[PATCH v5 0/6] Add xhci-exynos for Exynos SOC

[PATCH v5 0/6] Add xhci-exynos for Exynos SOC

[Daehwan Jung]

This patchset is for Samsung Exynos xHCI host conroller. It uses xhci
platform driver and extends some functions by xhci hooks and overrides.

This driver supports USB offload which makes Co-processor to use
some memories of xhci. Especially it's useful for USB Audio scenario.
Audio stream would get shortcut because Co-processor directly write/read
data in xhci memories. It could get speed-up using faster memory like SRAM.
That's why this gives vendors flexibilty of memory management. This feature
is done with xhci hooks and overrides.

It supports USB offload only for first connected device. It follows normal
sequence from 2nd device.

Changes in v2 :
- Fix commit message by adding Signed-off-by in each patch.
- Fix conflict on latest.

Changes in v3 :
- Remove export symbols and xhci hooks which xhci-exynos don't need.
- Modify commit message to clarify why it needs to export symbols.
- Check compiling of xhci-exynos.

Changes in v4 :
- Modify commit message to clarify why it needs to export symbols.
- Add a function for override of hc driver in xhci-plat.
- Make xhci-exynos extending xhci-plat by xhci hooks and overrides.
  (vendor_init / vendor_cleanup hooks are useful from here v4)
- Change the term (USB offload -> xhci-exynos) on subject of patches.

Changes in v5 :
- Rename subject of cover-letter.
- Add code in xhci_alloc_segments_for_uram.
- Add code for supporting several devices.
- Move adding xhci_address_device to other commit.
  (usb: host: add some to xhci overrides for xhci-exynos
    -> usb: host: export symbols for xhci-exynos to use xhci hooks)
- Add new commit (usb: dwc3: dwc3-exynos: add host init)

Daehwan Jung (6):
  usb: host: export symbols for xhci-exynos to use xhci hooks
  usb: host: add xhci hooks for xhci-exynos
  usb: host: xhci-plat: support override of hc driver
  usb: host: add some to xhci overrides for xhci-exynos
  usb: host: add xhci-exynos driver
  usb: dwc3: dwc3-exynos: add host init

 drivers/usb/dwc3/dwc3-exynos.c | 100 ++++-
 drivers/usb/host/Kconfig       |   8 +
 drivers/usb/host/Makefile      |   1 +
 drivers/usb/host/xhci-exynos.c | 775 +++++++++++++++++++++++++++++++++
 drivers/usb/host/xhci-hub.c    |   7 +
 drivers/usb/host/xhci-mem.c    | 150 ++++++-
 drivers/usb/host/xhci-plat.c   |  50 ++-
 drivers/usb/host/xhci-plat.h   |   9 +
 drivers/usb/host/xhci-ring.c   |   1 +
 drivers/usb/host/xhci.c        |  90 +++-
 drivers/usb/host/xhci.h        |  57 +++
 11 files changed, 1222 insertions(+), 26 deletions(-)
 create mode 100644 drivers/usb/host/xhci-exynos.c

-- 
2.31.1

[PATCH v5 1/6] usb: host: export symbols for xhci-exynos to use xhci hooks

[Daehwan Jung]

Export symbols for xhci hooks usage:
    xhci_get_slot_ctx
    xhci_get_endpoint_address
    - Allow xhci hook to get ep_ctx from the xhci_container_ctx for
      getting the ep_ctx information to know which ep is offloading and
      comparing the context in remote subsystem memory if needed.

    xhci_ring_alloc
    - Allow xhci hook to allocate vendor specific ring. Vendors could
      alloc additional event ring.

    xhci_trb_virt_to_dma
    - Used to retrieve the DMA address of vendor specific ring. Vendors
      could get dequeue address of event ring.

    xhci_segment_free
    xhci_link_segments
    - Allow xhci hook to handle vendor specific segment. Vendors could
      directly free or link segments of vendor specific ring.

    xhci_initialize_ring_info
    - Allow xhci hook to initialize vendor specific ring.

    xhci_check_trb_in_td_math
    - Allow xhci hook to Check TRB math for validation. Vendors could
      check trb when allocating vendor specific ring.

    xhci_address_device
    - Allow override to give configuration info to Co-processor.

    xhci_bus_suspend
    xhci_bus_resume
    - Allow override of suspend and resume for power scenario.

    xhci_remove_stream_mapping
    - Allow to xhci hook to remove stream mapping. Vendors need to do it
      when free-ing vendor specific ring if it's stream type.

Signed-off-by: Daehwan Jung <dh10.jung@samsung.com>
Signed-off-by: Jack Pham <jackp@codeaurora.org>
Signed-off-by: Howard Yen <howardyen@google.com>
---
 drivers/usb/host/xhci-hub.c  |  2 ++
 drivers/usb/host/xhci-mem.c  | 19 +++++++++++++------
 drivers/usb/host/xhci-ring.c |  1 +
 drivers/usb/host/xhci.c      |  4 +++-
 drivers/usb/host/xhci.h      |  7 +++++++
 5 files changed, 26 insertions(+), 7 deletions(-)

diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
index f65f1ba2b592..841617952ac7 100644
--- a/drivers/usb/host/xhci-hub.c
+++ b/drivers/usb/host/xhci-hub.c
@@ -1812,6 +1812,7 @@ int xhci_bus_suspend(struct usb_hcd *hcd)
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(xhci_bus_suspend);
 
 /*
  * Workaround for missing Cold Attach Status (CAS) if device re-plugged in S3.
@@ -1956,6 +1957,7 @@ int xhci_bus_resume(struct usb_hcd *hcd)
 	spin_unlock_irqrestore(&xhci->lock, flags);
 	return 0;
 }
+EXPORT_SYMBOL_GPL(xhci_bus_resume);
 
 unsigned long xhci_get_resuming_ports(struct usb_hcd *hcd)
 {
diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index bbb27ee2c6a3..82b9f90c0f27 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -65,7 +65,7 @@ static struct xhci_segment *xhci_segment_alloc(struct xhci_hcd *xhci,
 	return seg;
 }
 
-static void xhci_segment_free(struct xhci_hcd *xhci, struct xhci_segment *seg)
+void xhci_segment_free(struct xhci_hcd *xhci, struct xhci_segment *seg)
 {
 	if (seg->trbs) {
 		dma_pool_free(xhci->segment_pool, seg->trbs, seg->dma);
@@ -74,6 +74,7 @@ static void xhci_segment_free(struct xhci_hcd *xhci, struct xhci_segment *seg)
 	kfree(seg->bounce_buf);
 	kfree(seg);
 }
+EXPORT_SYMBOL_GPL(xhci_segment_free);
 
 static void xhci_free_segments_for_ring(struct xhci_hcd *xhci,
 				struct xhci_segment *first)
@@ -96,9 +97,9 @@ static void xhci_free_segments_for_ring(struct xhci_hcd *xhci,
  * DMA address of the next segment.  The caller needs to set any Link TRB
  * related flags, such as End TRB, Toggle Cycle, and no snoop.
  */
-static void xhci_link_segments(struct xhci_segment *prev,
-			       struct xhci_segment *next,
-			       enum xhci_ring_type type, bool chain_links)
+void xhci_link_segments(struct xhci_segment *prev,
+			struct xhci_segment *next,
+			enum xhci_ring_type type, bool chain_links)
 {
 	u32 val;
 
@@ -118,6 +119,7 @@ static void xhci_link_segments(struct xhci_segment *prev,
 		prev->trbs[TRBS_PER_SEGMENT-1].link.control = cpu_to_le32(val);
 	}
 }
+EXPORT_SYMBOL_GPL(xhci_link_segments);
 
 /*
  * Link the ring to the new segments.
@@ -256,7 +258,7 @@ static int xhci_update_stream_segment_mapping(
 	return ret;
 }
 
-static void xhci_remove_stream_mapping(struct xhci_ring *ring)
+void xhci_remove_stream_mapping(struct xhci_ring *ring)
 {
 	struct xhci_segment *seg;
 
@@ -269,6 +271,7 @@ static void xhci_remove_stream_mapping(struct xhci_ring *ring)
 		seg = seg->next;
 	} while (seg != ring->first_seg);
 }
+EXPORT_SYMBOL_GPL(xhci_remove_stream_mapping);
 
 static int xhci_update_stream_mapping(struct xhci_ring *ring, gfp_t mem_flags)
 {
@@ -316,6 +319,7 @@ void xhci_initialize_ring_info(struct xhci_ring *ring,
 	 */
 	ring->num_trbs_free = ring->num_segs * (TRBS_PER_SEGMENT - 1) - 1;
 }
+EXPORT_SYMBOL_GPL(xhci_initialize_ring_info);
 
 /* Allocate segments and link them for a ring */
 static int xhci_alloc_segments_for_ring(struct xhci_hcd *xhci,
@@ -407,6 +411,7 @@ struct xhci_ring *xhci_ring_alloc(struct xhci_hcd *xhci,
 	kfree(ring);
 	return NULL;
 }
+EXPORT_SYMBOL_GPL(xhci_ring_alloc);
 
 void xhci_free_endpoint_ring(struct xhci_hcd *xhci,
 		struct xhci_virt_device *virt_dev,
@@ -518,6 +523,7 @@ struct xhci_slot_ctx *xhci_get_slot_ctx(struct xhci_hcd *xhci,
 	return (struct xhci_slot_ctx *)
 		(ctx->bytes + CTX_SIZE(xhci->hcc_params));
 }
+EXPORT_SYMBOL_GPL(xhci_get_slot_ctx);
 
 struct xhci_ep_ctx *xhci_get_ep_ctx(struct xhci_hcd *xhci,
 				    struct xhci_container_ctx *ctx,
@@ -1965,7 +1971,7 @@ static int xhci_test_trb_in_td(struct xhci_hcd *xhci,
 }
 
 /* TRB math checks for xhci_trb_in_td(), using the command and event rings. */
-static int xhci_check_trb_in_td_math(struct xhci_hcd *xhci)
+int xhci_check_trb_in_td_math(struct xhci_hcd *xhci)
 {
 	struct {
 		dma_addr_t		input_dma;
@@ -2085,6 +2091,7 @@ static int xhci_check_trb_in_td_math(struct xhci_hcd *xhci)
 	xhci_dbg(xhci, "TRB math tests passed.\n");
 	return 0;
 }
+EXPORT_SYMBOL_GPL(xhci_check_trb_in_td_math);
 
 static void xhci_set_hc_event_deq(struct xhci_hcd *xhci)
 {
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index f9707997969d..652b37cd9c5e 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -79,6 +79,7 @@ dma_addr_t xhci_trb_virt_to_dma(struct xhci_segment *seg,
 		return 0;
 	return seg->dma + (segment_offset * sizeof(*trb));
 }
+EXPORT_SYMBOL_GPL(xhci_trb_virt_to_dma);
 
 static bool trb_is_noop(union xhci_trb *trb)
 {
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 25b87e99b4dd..c06e8b21b724 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -1468,6 +1468,7 @@ unsigned int xhci_get_endpoint_address(unsigned int ep_index)
 	unsigned int direction = ep_index % 2 ? USB_DIR_OUT : USB_DIR_IN;
 	return direction | number;
 }
+EXPORT_SYMBOL_GPL(xhci_get_endpoint_address);
 
 /* Find the flag for this endpoint (for use in the control context).  Use the
  * endpoint index to create a bitmask.  The slot context is bit 0, endpoint 0 is
@@ -4324,10 +4325,11 @@ static int xhci_setup_device(struct usb_hcd *hcd, struct usb_device *udev,
 	return ret;
 }
 
-static int xhci_address_device(struct usb_hcd *hcd, struct usb_device *udev)
+int xhci_address_device(struct usb_hcd *hcd, struct usb_device *udev)
 {
 	return xhci_setup_device(hcd, udev, SETUP_CONTEXT_ADDRESS);
 }
+EXPORT_SYMBOL_GPL(xhci_address_device);
 
 static int xhci_enable_device(struct usb_hcd *hcd, struct usb_device *udev)
 {
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 473a33ce299e..5316841e9b26 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -2054,6 +2054,11 @@ void xhci_free_erst(struct xhci_hcd *xhci, struct xhci_erst *erst);
 void xhci_free_endpoint_ring(struct xhci_hcd *xhci,
 		struct xhci_virt_device *virt_dev,
 		unsigned int ep_index);
+void xhci_segment_free(struct xhci_hcd *xhci, struct xhci_segment *seg);
+void xhci_link_segments(struct xhci_segment *prev,
+			struct xhci_segment *next,
+			enum xhci_ring_type type, bool chain_links);
+void xhci_remove_stream_mapping(struct xhci_ring *ring);
 struct xhci_stream_info *xhci_alloc_stream_info(struct xhci_hcd *xhci,
 		unsigned int num_stream_ctxs,
 		unsigned int num_streams,
@@ -2100,6 +2105,7 @@ int xhci_drop_endpoint(struct usb_hcd *hcd, struct usb_device *udev,
 		       struct usb_host_endpoint *ep);
 int xhci_check_bandwidth(struct usb_hcd *hcd, struct usb_device *udev);
 void xhci_reset_bandwidth(struct usb_hcd *hcd, struct usb_device *udev);
+int xhci_address_device(struct usb_hcd *hcd, struct usb_device *udev);
 int xhci_disable_slot(struct xhci_hcd *xhci, u32 slot_id);
 int xhci_ext_cap_init(struct xhci_hcd *xhci);
 
@@ -2116,6 +2122,7 @@ int xhci_alloc_tt_info(struct xhci_hcd *xhci,
 
 /* xHCI ring, segment, TRB, and TD functions */
 dma_addr_t xhci_trb_virt_to_dma(struct xhci_segment *seg, union xhci_trb *trb);
+int xhci_check_trb_in_td_math(struct xhci_hcd *xhci);
 struct xhci_segment *trb_in_td(struct xhci_hcd *xhci,
 		struct xhci_segment *start_seg, union xhci_trb *start_trb,
 		union xhci_trb *end_trb, dma_addr_t suspect_dma, bool debug);
-- 
2.31.1

[PATCH v5 2/6] usb: host: add xhci hooks for xhci-exynos

[Daehwan Jung]

To enable supporting for USB offload, define "offload" in usb controller
node of device tree. "offload" value can be used to determine which type
of offload was been enabled in the SoC.

For example:

&usbdrd_dwc3 {
        ...
        /* support usb offloading, 0: disabled, 1: audio */
        offload = <1>;
        ...
};

There are several vendor_ops introduced by this patch:

struct xhci_vendor_ops - function callbacks for vendor specific operations
{
        @vendor_init:
                - called for vendor init process during xhci-plat-hcd
                  probe.
        @vendor_cleanup:
                - called for vendor cleanup process during xhci-plat-hcd
                  remove.
        @is_usb_offload_enabled:
                - called to check if usb offload enabled.
        @alloc_dcbaa:
                - called when allocating vendor specific dcbaa during
                  memory initializtion.
        @free_dcbaa:
                - called to free vendor specific dcbaa when cleanup the
                  memory.
        @alloc_transfer_ring:
                - called when vendor specific transfer ring allocation is required
        @free_transfer_ring:
                - called to free vendor specific transfer ring
        @sync_dev_ctx:
                - called when synchronization for device context is required
	@alloc_container_ctx
		- called to alloc vendor specific container context
	@free_container_ctx
		- called to free vendor specific container context
}

The xhci hooks with prefix "xhci_vendor_" on the ops in xhci_vendor_ops.
For example, vendor_init ops will be invoked by xhci_vendor_init() hook,
is_usb_offload_enabled ops will be invoked by
xhci_vendor_is_usb_offload_enabled(), and so on.

Signed-off-by: Daehwan Jung <dh10.jung@samsung.com>
Signed-off-by: J. Avila <elavila@google.com>
Signed-off-by: Puma Hsu <pumahsu@google.com>
Signed-off-by: Howard Yen <howardyen@google.com>
---
 drivers/usb/host/xhci-hub.c  |   5 ++
 drivers/usb/host/xhci-mem.c  | 131 +++++++++++++++++++++++++++++++----
 drivers/usb/host/xhci-plat.c |  44 +++++++++++-
 drivers/usb/host/xhci-plat.h |   8 +++
 drivers/usb/host/xhci.c      |  80 ++++++++++++++++++++-
 drivers/usb/host/xhci.h      |  47 +++++++++++++
 6 files changed, 297 insertions(+), 18 deletions(-)

diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
index 841617952ac7..e07c9c132061 100644
--- a/drivers/usb/host/xhci-hub.c
+++ b/drivers/usb/host/xhci-hub.c
@@ -535,8 +535,13 @@ static int xhci_stop_device(struct xhci_hcd *xhci, int slot_id, int suspend)
 	    cmd->status == COMP_COMMAND_RING_STOPPED) {
 		xhci_warn(xhci, "Timeout while waiting for stop endpoint command\n");
 		ret = -ETIME;
+		goto cmd_cleanup;
 	}
 
+	ret = xhci_vendor_sync_dev_ctx(xhci, slot_id);
+	if (ret)
+		xhci_warn(xhci, "Sync device context failed, ret=%d\n", ret);
+
 cmd_cleanup:
 	xhci_free_command(xhci, cmd);
 	return ret;
diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index 82b9f90c0f27..5ee0ffb676d3 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -365,6 +365,54 @@ static int xhci_alloc_segments_for_ring(struct xhci_hcd *xhci,
 	return 0;
 }
 
+static void xhci_vendor_free_container_ctx(struct xhci_hcd *xhci, struct xhci_container_ctx *ctx)
+{
+	struct xhci_vendor_ops *ops = xhci_vendor_get_ops(xhci);
+
+	if (ops && ops->free_container_ctx)
+		ops->free_container_ctx(xhci, ctx);
+}
+
+static void xhci_vendor_alloc_container_ctx(struct xhci_hcd *xhci, struct xhci_container_ctx *ctx,
+					    int type, gfp_t flags)
+{
+	struct xhci_vendor_ops *ops = xhci_vendor_get_ops(xhci);
+
+	if (ops && ops->alloc_container_ctx)
+		ops->alloc_container_ctx(xhci, ctx, type, flags);
+}
+
+static struct xhci_ring *xhci_vendor_alloc_transfer_ring(struct xhci_hcd *xhci,
+		u32 endpoint_type, enum xhci_ring_type ring_type,
+		unsigned int max_packet, gfp_t mem_flags)
+{
+	struct xhci_vendor_ops *ops = xhci_vendor_get_ops(xhci);
+
+	if (ops && ops->alloc_transfer_ring)
+		return ops->alloc_transfer_ring(xhci, endpoint_type, ring_type,
+				max_packet, mem_flags);
+	return 0;
+}
+
+void xhci_vendor_free_transfer_ring(struct xhci_hcd *xhci,
+		struct xhci_ring *ring, unsigned int ep_index)
+{
+	struct xhci_vendor_ops *ops = xhci_vendor_get_ops(xhci);
+
+	if (ops && ops->free_transfer_ring)
+		ops->free_transfer_ring(xhci, ring, ep_index);
+}
+
+bool xhci_vendor_is_usb_offload_enabled(struct xhci_hcd *xhci,
+		struct xhci_virt_device *virt_dev, unsigned int ep_index)
+{
+	struct xhci_vendor_ops *ops = xhci_vendor_get_ops(xhci);
+
+	if (ops && ops->is_usb_offload_enabled)
+		return ops->is_usb_offload_enabled(xhci, virt_dev, ep_index);
+	return false;
+}
+
 /*
  * Create a new ring with zero or more segments.
  *
@@ -417,7 +465,11 @@ void xhci_free_endpoint_ring(struct xhci_hcd *xhci,
 		struct xhci_virt_device *virt_dev,
 		unsigned int ep_index)
 {
-	xhci_ring_free(xhci, virt_dev->eps[ep_index].ring);
+	if (xhci_vendor_is_usb_offload_enabled(xhci, virt_dev, ep_index))
+		xhci_vendor_free_transfer_ring(xhci, virt_dev->eps[ep_index].ring, ep_index);
+	else
+		xhci_ring_free(xhci, virt_dev->eps[ep_index].ring);
+
 	virt_dev->eps[ep_index].ring = NULL;
 }
 
@@ -475,6 +527,7 @@ struct xhci_container_ctx *xhci_alloc_container_ctx(struct xhci_hcd *xhci,
 {
 	struct xhci_container_ctx *ctx;
 	struct device *dev = xhci_to_hcd(xhci)->self.sysdev;
+	struct xhci_vendor_ops *ops = xhci_vendor_get_ops(xhci);
 
 	if ((type != XHCI_CTX_TYPE_DEVICE) && (type != XHCI_CTX_TYPE_INPUT))
 		return NULL;
@@ -488,7 +541,12 @@ struct xhci_container_ctx *xhci_alloc_container_ctx(struct xhci_hcd *xhci,
 	if (type == XHCI_CTX_TYPE_INPUT)
 		ctx->size += CTX_SIZE(xhci->hcc_params);
 
-	ctx->bytes = dma_pool_zalloc(xhci->device_pool, flags, &ctx->dma);
+	if (xhci_vendor_is_usb_offload_enabled(xhci, NULL, 0) &&
+	    (ops && ops->alloc_container_ctx))
+		xhci_vendor_alloc_container_ctx(xhci, ctx, type, flags);
+	else
+		ctx->bytes = dma_pool_zalloc(xhci->device_pool, flags, &ctx->dma);
+
 	if (!ctx->bytes) {
 		kfree(ctx);
 		return NULL;
@@ -499,9 +557,16 @@ struct xhci_container_ctx *xhci_alloc_container_ctx(struct xhci_hcd *xhci,
 void xhci_free_container_ctx(struct xhci_hcd *xhci,
 			     struct xhci_container_ctx *ctx)
 {
+	struct xhci_vendor_ops *ops = xhci_vendor_get_ops(xhci);
+
 	if (!ctx)
 		return;
-	dma_pool_free(xhci->device_pool, ctx->bytes, ctx->dma);
+	if (xhci_vendor_is_usb_offload_enabled(xhci, NULL, 0) &&
+	    (ops && ops->free_container_ctx))
+		xhci_vendor_free_container_ctx(xhci, ctx);
+	else
+		dma_pool_free(xhci->device_pool, ctx->bytes, ctx->dma);
+
 	kfree(ctx);
 }
 
@@ -894,7 +959,7 @@ void xhci_free_virt_device(struct xhci_hcd *xhci, int slot_id)
 
 	for (i = 0; i < 31; i++) {
 		if (dev->eps[i].ring)
-			xhci_ring_free(xhci, dev->eps[i].ring);
+			xhci_free_endpoint_ring(xhci, dev, i);
 		if (dev->eps[i].stream_info)
 			xhci_free_stream_info(xhci,
 					dev->eps[i].stream_info);
@@ -1492,8 +1557,16 @@ int xhci_endpoint_init(struct xhci_hcd *xhci,
 		mult = 0;
 
 	/* Set up the endpoint ring */
-	virt_dev->eps[ep_index].new_ring =
-		xhci_ring_alloc(xhci, 2, 1, ring_type, max_packet, mem_flags);
+	if (xhci_vendor_is_usb_offload_enabled(xhci, virt_dev, ep_index) &&
+	    usb_endpoint_xfer_isoc(&ep->desc)) {
+		virt_dev->eps[ep_index].new_ring =
+			xhci_vendor_alloc_transfer_ring(xhci, endpoint_type, ring_type,
+							max_packet, mem_flags);
+	} else {
+		virt_dev->eps[ep_index].new_ring =
+			xhci_ring_alloc(xhci, 2, 1, ring_type, max_packet, mem_flags);
+	}
+
 	if (!virt_dev->eps[ep_index].new_ring)
 		return -ENOMEM;
 
@@ -1837,6 +1910,24 @@ void xhci_free_erst(struct xhci_hcd *xhci, struct xhci_erst *erst)
 	erst->entries = NULL;
 }
 
+static struct xhci_device_context_array *xhci_vendor_alloc_dcbaa(
+		struct xhci_hcd *xhci, gfp_t flags)
+{
+	struct xhci_vendor_ops *ops = xhci_vendor_get_ops(xhci);
+
+	if (ops && ops->alloc_dcbaa)
+		return ops->alloc_dcbaa(xhci, flags);
+	return 0;
+}
+
+static void xhci_vendor_free_dcbaa(struct xhci_hcd *xhci)
+{
+	struct xhci_vendor_ops *ops = xhci_vendor_get_ops(xhci);
+
+	if (ops && ops->free_dcbaa)
+		ops->free_dcbaa(xhci);
+}
+
 void xhci_mem_cleanup(struct xhci_hcd *xhci)
 {
 	struct device	*dev = xhci_to_hcd(xhci)->self.sysdev;
@@ -1888,9 +1979,13 @@ void xhci_mem_cleanup(struct xhci_hcd *xhci)
 	xhci_dbg_trace(xhci, trace_xhci_dbg_init,
 			"Freed medium stream array pool");
 
-	if (xhci->dcbaa)
-		dma_free_coherent(dev, sizeof(*xhci->dcbaa),
-				xhci->dcbaa, xhci->dcbaa->dma);
+	if (xhci_vendor_is_usb_offload_enabled(xhci, NULL, 0)) {
+		xhci_vendor_free_dcbaa(xhci);
+	} else {
+		if (xhci->dcbaa)
+			dma_free_coherent(dev, sizeof(*xhci->dcbaa),
+					xhci->dcbaa, xhci->dcbaa->dma);
+	}
 	xhci->dcbaa = NULL;
 
 	scratchpad_free(xhci);
@@ -2427,15 +2522,21 @@ int xhci_mem_init(struct xhci_hcd *xhci, gfp_t flags)
 	 * xHCI section 5.4.6 - Device Context array must be
 	 * "physically contiguous and 64-byte (cache line) aligned".
 	 */
-	xhci->dcbaa = dma_alloc_coherent(dev, sizeof(*xhci->dcbaa), &dma,
-			flags);
-	if (!xhci->dcbaa)
-		goto fail;
-	xhci->dcbaa->dma = dma;
+	if (xhci_vendor_is_usb_offload_enabled(xhci, NULL, 0)) {
+		xhci->dcbaa = xhci_vendor_alloc_dcbaa(xhci, flags);
+		if (!xhci->dcbaa)
+			goto fail;
+	} else {
+		xhci->dcbaa = dma_alloc_coherent(dev, sizeof(*xhci->dcbaa), &dma,
+				flags);
+		if (!xhci->dcbaa)
+			goto fail;
+		xhci->dcbaa->dma = dma;
+	}
 	xhci_dbg_trace(xhci, trace_xhci_dbg_init,
 			"// Device context base array address = 0x%llx (DMA), %p (virt)",
 			(unsigned long long)xhci->dcbaa->dma, xhci->dcbaa);
-	xhci_write_64(xhci, dma, &xhci->op_regs->dcbaa_ptr);
+	xhci_write_64(xhci, xhci->dcbaa->dma, &xhci->op_regs->dcbaa_ptr);
 
 	/*
 	 * Initialize the ring segment pool.  The ring must be a contiguous
diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
index 649ffd861b44..a5881ff945a6 100644
--- a/drivers/usb/host/xhci-plat.c
+++ b/drivers/usb/host/xhci-plat.c
@@ -173,6 +173,41 @@ static const struct of_device_id usb_xhci_of_match[] = {
 MODULE_DEVICE_TABLE(of, usb_xhci_of_match);
 #endif
 
+static struct xhci_plat_priv_overwrite xhci_plat_vendor_overwrite;
+
+int xhci_plat_register_vendor_ops(struct xhci_vendor_ops *vendor_ops)
+{
+	if (vendor_ops == NULL)
+		return -EINVAL;
+
+	xhci_plat_vendor_overwrite.vendor_ops = vendor_ops;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(xhci_plat_register_vendor_ops);
+
+static int xhci_vendor_init(struct xhci_hcd *xhci, struct device *dev)
+{
+	struct xhci_vendor_ops *ops = NULL;
+
+	if (xhci_plat_vendor_overwrite.vendor_ops)
+		ops = xhci->vendor_ops = xhci_plat_vendor_overwrite.vendor_ops;
+
+	if (ops && ops->vendor_init)
+		return ops->vendor_init(xhci, dev);
+	return 0;
+}
+
+static void xhci_vendor_cleanup(struct xhci_hcd *xhci)
+{
+	struct xhci_vendor_ops *ops = xhci_vendor_get_ops(xhci);
+
+	if (ops && ops->vendor_cleanup)
+		ops->vendor_cleanup(xhci);
+
+	xhci->vendor_ops = NULL;
+}
+
 static int xhci_plat_probe(struct platform_device *pdev)
 {
 	const struct xhci_plat_priv *priv_match;
@@ -185,7 +220,6 @@ static int xhci_plat_probe(struct platform_device *pdev)
 	int			irq;
 	struct xhci_plat_priv	*priv = NULL;
 
-
 	if (usb_disabled())
 		return -ENODEV;
 
@@ -321,6 +355,10 @@ static int xhci_plat_probe(struct platform_device *pdev)
 			goto put_usb3_hcd;
 	}
 
+	ret = xhci_vendor_init(xhci, &pdev->dev);
+	if (ret)
+		goto disable_usb_phy;
+
 	hcd->tpl_support = of_usb_host_tpl_support(sysdev->of_node);
 	xhci->shared_hcd->tpl_support = hcd->tpl_support;
 	if (priv && (priv->quirks & XHCI_SKIP_PHY_INIT))
@@ -393,8 +431,10 @@ static int xhci_plat_remove(struct platform_device *dev)
 	usb_phy_shutdown(hcd->usb_phy);
 
 	usb_remove_hcd(hcd);
-	usb_put_hcd(shared_hcd);
 
+	xhci_vendor_cleanup(xhci);
+
+	usb_put_hcd(shared_hcd);
 	clk_disable_unprepare(clk);
 	clk_disable_unprepare(reg_clk);
 	usb_put_hcd(hcd);
diff --git a/drivers/usb/host/xhci-plat.h b/drivers/usb/host/xhci-plat.h
index 1fb149d1fbce..8c204f3234d8 100644
--- a/drivers/usb/host/xhci-plat.h
+++ b/drivers/usb/host/xhci-plat.h
@@ -17,8 +17,16 @@ struct xhci_plat_priv {
 	int (*init_quirk)(struct usb_hcd *);
 	int (*suspend_quirk)(struct usb_hcd *);
 	int (*resume_quirk)(struct usb_hcd *);
+	void *vendor_priv;
 };
 
 #define hcd_to_xhci_priv(h) ((struct xhci_plat_priv *)hcd_to_xhci(h)->priv)
 #define xhci_to_priv(x) ((struct xhci_plat_priv *)(x)->priv)
+
+struct xhci_plat_priv_overwrite {
+	struct xhci_vendor_ops *vendor_ops;
+};
+
+int xhci_plat_register_vendor_ops(struct xhci_vendor_ops *vendor_ops);
+
 #endif	/* _XHCI_PLAT_H */
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index c06e8b21b724..5ccf1bbe8732 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -2986,6 +2986,14 @@ static int xhci_configure_endpoint(struct xhci_hcd *xhci,
 			xhci_finish_resource_reservation(xhci, ctrl_ctx);
 		spin_unlock_irqrestore(&xhci->lock, flags);
 	}
+	if (ret)
+		goto failed;
+
+	ret = xhci_vendor_sync_dev_ctx(xhci, udev->slot_id);
+	if (ret)
+		xhci_warn(xhci, "sync device context failed, ret=%d", ret);
+
+failed:
 	return ret;
 }
 
@@ -3129,7 +3137,11 @@ void xhci_reset_bandwidth(struct usb_hcd *hcd, struct usb_device *udev)
 	for (i = 0; i < 31; i++) {
 		if (virt_dev->eps[i].new_ring) {
 			xhci_debugfs_remove_endpoint(xhci, virt_dev, i);
-			xhci_ring_free(xhci, virt_dev->eps[i].new_ring);
+			if (xhci_vendor_is_usb_offload_enabled(xhci, virt_dev, i))
+				xhci_vendor_free_transfer_ring(xhci, virt_dev->eps[i].new_ring, i);
+			else
+				xhci_ring_free(xhci, virt_dev->eps[i].new_ring);
+
 			virt_dev->eps[i].new_ring = NULL;
 		}
 	}
@@ -3290,6 +3302,13 @@ static void xhci_endpoint_reset(struct usb_hcd *hcd,
 
 	wait_for_completion(stop_cmd->completion);
 
+	err = xhci_vendor_sync_dev_ctx(xhci, udev->slot_id);
+	if (err) {
+		xhci_warn(xhci, "%s: Failed to sync device context failed, err=%d",
+			  __func__, err);
+		goto cleanup;
+	}
+
 	spin_lock_irqsave(&xhci->lock, flags);
 
 	/* config ep command clears toggle if add and drop ep flags are set */
@@ -3321,6 +3340,11 @@ static void xhci_endpoint_reset(struct usb_hcd *hcd,
 
 	wait_for_completion(cfg_cmd->completion);
 
+	err = xhci_vendor_sync_dev_ctx(xhci, udev->slot_id);
+	if (err)
+		xhci_warn(xhci, "%s: Failed to sync device context failed, err=%d",
+			  __func__, err);
+
 	xhci_free_command(xhci, cfg_cmd);
 cleanup:
 	xhci_free_command(xhci, stop_cmd);
@@ -3866,6 +3890,13 @@ static int xhci_discover_or_reset_device(struct usb_hcd *hcd,
 	/* Wait for the Reset Device command to finish */
 	wait_for_completion(reset_device_cmd->completion);
 
+	ret = xhci_vendor_sync_dev_ctx(xhci, slot_id);
+	if (ret) {
+		xhci_warn(xhci, "%s: Failed to sync device context failed, err=%d",
+			  __func__, ret);
+		goto command_cleanup;
+	}
+
 	/* The Reset Device command can't fail, according to the 0.95/0.96 spec,
 	 * unless we tried to reset a slot ID that wasn't enabled,
 	 * or the device wasn't in the addressed or configured state.
@@ -4111,6 +4142,14 @@ int xhci_alloc_dev(struct usb_hcd *hcd, struct usb_device *udev)
 		xhci_warn(xhci, "Could not allocate xHCI USB device data structures\n");
 		goto disable_slot;
 	}
+
+	ret = xhci_vendor_sync_dev_ctx(xhci, slot_id);
+	if (ret) {
+		xhci_warn(xhci, "%s: Failed to sync device context failed, err=%d",
+			  __func__, ret);
+		goto disable_slot;
+	}
+
 	vdev = xhci->devs[slot_id];
 	slot_ctx = xhci_get_slot_ctx(xhci, vdev->out_ctx);
 	trace_xhci_alloc_dev(slot_ctx);
@@ -4241,6 +4280,13 @@ static int xhci_setup_device(struct usb_hcd *hcd, struct usb_device *udev,
 	/* ctrl tx can take up to 5 sec; XXX: need more time for xHC? */
 	wait_for_completion(command->completion);
 
+	ret = xhci_vendor_sync_dev_ctx(xhci, udev->slot_id);
+	if (ret) {
+		xhci_warn(xhci, "%s: Failed to sync device context failed, err=%d",
+			  __func__, ret);
+		goto out;
+	}
+
 	/* FIXME: From section 4.3.4: "Software shall be responsible for timing
 	 * the SetAddress() "recovery interval" required by USB and aborting the
 	 * command on a timeout.
@@ -4393,6 +4439,14 @@ static int __maybe_unused xhci_change_max_exit_latency(struct xhci_hcd *xhci,
 		return -ENOMEM;
 	}
 
+	ret = xhci_vendor_sync_dev_ctx(xhci, udev->slot_id);
+	if (ret) {
+		spin_unlock_irqrestore(&xhci->lock, flags);
+		xhci_warn(xhci, "%s: Failed to sync device context failed, err=%d",
+			  __func__, ret);
+		return ret;
+	}
+
 	xhci_slot_copy(xhci, command->in_ctx, virt_dev->out_ctx);
 	spin_unlock_irqrestore(&xhci->lock, flags);
 
@@ -4420,6 +4474,21 @@ static int __maybe_unused xhci_change_max_exit_latency(struct xhci_hcd *xhci,
 	return ret;
 }
 
+struct xhci_vendor_ops *xhci_vendor_get_ops(struct xhci_hcd *xhci)
+{
+	return xhci->vendor_ops;
+}
+EXPORT_SYMBOL_GPL(xhci_vendor_get_ops);
+
+int xhci_vendor_sync_dev_ctx(struct xhci_hcd *xhci, unsigned int slot_id)
+{
+	struct xhci_vendor_ops *ops = xhci_vendor_get_ops(xhci);
+
+	if (ops && ops->sync_dev_ctx)
+		return ops->sync_dev_ctx(xhci, slot_id);
+	return 0;
+}
+
 #ifdef CONFIG_PM
 
 /* BESL to HIRD Encoding array for USB2 LPM */
@@ -5144,6 +5213,15 @@ static int xhci_update_hub_device(struct usb_hcd *hcd, struct usb_device *hdev,
 		return -ENOMEM;
 	}
 
+	ret = xhci_vendor_sync_dev_ctx(xhci, hdev->slot_id);
+	if (ret) {
+		xhci_warn(xhci, "%s: Failed to sync device context failed, err=%d",
+			  __func__, ret);
+		xhci_free_command(xhci, config_cmd);
+		spin_unlock_irqrestore(&xhci->lock, flags);
+		return ret;
+	}
+
 	xhci_slot_copy(xhci, config_cmd->in_ctx, vdev->out_ctx);
 	ctrl_ctx->add_flags |= cpu_to_le32(SLOT_FLAG);
 	slot_ctx = xhci_get_slot_ctx(xhci, config_cmd->in_ctx);
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 5316841e9b26..5d356f40c2b9 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1929,6 +1929,9 @@ struct xhci_hcd {
 	struct list_head	regset_list;
 
 	void			*dbc;
+
+	struct xhci_vendor_ops *vendor_ops;
+
 	/* platform-specific data -- must come last */
 	unsigned long		priv[] __aligned(sizeof(s64));
 };
@@ -2214,6 +2217,50 @@ static inline struct xhci_ring *xhci_urb_to_transfer_ring(struct xhci_hcd *xhci,
 					urb->stream_id);
 }
 
+/**
+ * struct xhci_vendor_ops - function callbacks for vendor specific operations
+ * @vendor_init: called for vendor init process
+ * @vendor_cleanup: called for vendor cleanup process
+ * @is_usb_offload_enabled: called to check if usb offload enabled
+ * @alloc_dcbaa: called when allocating vendor specific dcbaa
+ * @free_dcbaa: called to free vendor specific dcbaa
+ * @alloc_transfer_ring: called when remote transfer ring allocation is required
+ * @free_transfer_ring: called to free vendor specific transfer ring
+ * @sync_dev_ctx: called when synchronization for device context is required
+ * @alloc_container_ctx: called when allocating vendor specific container context
+ * @free_container_ctx: called to free vendor specific container context
+ */
+struct xhci_vendor_ops {
+	int (*vendor_init)(struct xhci_hcd *xhci, struct device *dev);
+	void (*vendor_cleanup)(struct xhci_hcd *xhci);
+	bool (*is_usb_offload_enabled)(struct xhci_hcd *xhci,
+				       struct xhci_virt_device *vdev,
+				       unsigned int ep_index);
+
+	struct xhci_device_context_array *(*alloc_dcbaa)(struct xhci_hcd *xhci,
+							 gfp_t flags);
+	void (*free_dcbaa)(struct xhci_hcd *xhci);
+
+	struct xhci_ring *(*alloc_transfer_ring)(struct xhci_hcd *xhci,
+			u32 endpoint_type, enum xhci_ring_type ring_type,
+			unsigned int max_packet, gfp_t mem_flags);
+	void (*free_transfer_ring)(struct xhci_hcd *xhci,
+			struct xhci_ring *ring, unsigned int ep_index);
+	int (*sync_dev_ctx)(struct xhci_hcd *xhci, unsigned int slot_id);
+	void (*alloc_container_ctx)(struct xhci_hcd *xhci, struct xhci_container_ctx *ctx,
+				    int type, gfp_t flags);
+	void (*free_container_ctx)(struct xhci_hcd *xhci, struct xhci_container_ctx *ctx);
+};
+/**
+ * Only Below vendor ops are non-static. That's why we add prototype here.
+ */
+struct xhci_vendor_ops *xhci_vendor_get_ops(struct xhci_hcd *xhci);
+int xhci_vendor_sync_dev_ctx(struct xhci_hcd *xhci, unsigned int slot_id);
+void xhci_vendor_free_transfer_ring(struct xhci_hcd *xhci,
+		struct xhci_ring *ring, unsigned int ep_index);
+bool xhci_vendor_is_usb_offload_enabled(struct xhci_hcd *xhci,
+		struct xhci_virt_device *virt_dev, unsigned int ep_index);
+
 /*
  * TODO: As per spec Isochronous IDT transmissions are supported. We bypass
  * them anyways as we where unable to find a device that matches the
-- 
2.31.1

[PATCH v5 3/6] usb: host: xhci-plat: support override of hc driver

[Daehwan Jung]

It helps xhci-plat driver increase usability. Vendors could use functions
in xhci-plat mostly and use some overrides to do what they wants without
modifying xhci-plat driver.

Signed-off-by: Daehwan Jung <dh10.jung@samsung.com>
---
 drivers/usb/host/xhci-plat.c | 6 ++++++
 drivers/usb/host/xhci-plat.h | 1 +
 2 files changed, 7 insertions(+)

diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
index a5881ff945a6..a340e14ce9a6 100644
--- a/drivers/usb/host/xhci-plat.c
+++ b/drivers/usb/host/xhci-plat.c
@@ -173,6 +173,12 @@ static const struct of_device_id usb_xhci_of_match[] = {
 MODULE_DEVICE_TABLE(of, usb_xhci_of_match);
 #endif
 
+void xhci_plat_override_driver(const struct xhci_driver_overrides *xhci_vendor_overrides)
+{
+	xhci_init_driver(&xhci_plat_hc_driver, xhci_vendor_overrides);
+}
+EXPORT_SYMBOL_GPL(xhci_plat_override_driver);
+
 static struct xhci_plat_priv_overwrite xhci_plat_vendor_overwrite;
 
 int xhci_plat_register_vendor_ops(struct xhci_vendor_ops *vendor_ops)
diff --git a/drivers/usb/host/xhci-plat.h b/drivers/usb/host/xhci-plat.h
index 8c204f3234d8..455e0018d5e6 100644
--- a/drivers/usb/host/xhci-plat.h
+++ b/drivers/usb/host/xhci-plat.h
@@ -28,5 +28,6 @@ struct xhci_plat_priv_overwrite {
 };
 
 int xhci_plat_register_vendor_ops(struct xhci_vendor_ops *vendor_ops);
+void xhci_plat_override_driver(const struct xhci_driver_overrides *xhci_vendor_overrides);
 
 #endif	/* _XHCI_PLAT_H */
-- 
2.31.1

[PATCH v5 4/6] usb: host: add some to xhci overrides for xhci-exynos

[Daehwan Jung]

Co-processor needs some information about connected usb device.
It's proper to pass information after usb device gets address when
getting "Set Address" command. It supports vendors to implement it
using xhci overrides. There're several power scenarios depending
on vendors. It gives vendors flexibilty to meet their power requirement.
They can override suspend and resume of root hub.

Signed-off-by: Daehwan Jung <dh10.jung@samsung.com>
---
 drivers/usb/host/xhci.c | 6 ++++++
 drivers/usb/host/xhci.h | 3 +++
 2 files changed, 9 insertions(+)

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 5ccf1bbe8732..8b3df1302650 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -5555,6 +5555,12 @@ void xhci_init_driver(struct hc_driver *drv,
 			drv->check_bandwidth = over->check_bandwidth;
 		if (over->reset_bandwidth)
 			drv->reset_bandwidth = over->reset_bandwidth;
+		if (over->address_device)
+			drv->address_device = over->address_device;
+		if (over->bus_suspend)
+			drv->bus_suspend = over->bus_suspend;
+		if (over->bus_resume)
+			drv->bus_resume = over->bus_resume;
 	}
 }
 EXPORT_SYMBOL_GPL(xhci_init_driver);
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 5d356f40c2b9..ab74b24a13b3 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1947,6 +1947,9 @@ struct xhci_driver_overrides {
 			     struct usb_host_endpoint *ep);
 	int (*check_bandwidth)(struct usb_hcd *, struct usb_device *);
 	void (*reset_bandwidth)(struct usb_hcd *, struct usb_device *);
+	int (*address_device)(struct usb_hcd *hcd, struct usb_device *udev);
+	int (*bus_suspend)(struct usb_hcd *hcd);
+	int (*bus_resume)(struct usb_hcd *hcd);
 };
 
 #define	XHCI_CFC_DELAY		10
-- 
2.31.1

[PATCH RFC v5 5/6] usb: host: add xhci-exynos driver

[Daehwan Jung]

This driver is for Samsung Exynos xHCI host conroller. It works based on
xhci platform driver and extends functions by xhci hooks and overrides.
Vendor ops(xhci hooks) should be mapped before probing driver.
It overrides functions of hc driver on vendor init.

It supports USB Audio offload with Co-processor. It only cares DCBAA,
Device Context, Transfer Ring, Event Ring, and ERST. They are allocated
on specific address with xhci hooks. Co-processor could use them directly
without xhci driver after then.

Signed-off-by: Daehwan Jung <dh10.jung@samsung.com>
---
 drivers/usb/host/Kconfig       |   8 +
 drivers/usb/host/Makefile      |   1 +
 drivers/usb/host/xhci-exynos.c | 775 +++++++++++++++++++++++++++++++++
 3 files changed, 784 insertions(+)
 create mode 100644 drivers/usb/host/xhci-exynos.c

diff --git a/drivers/usb/host/Kconfig b/drivers/usb/host/Kconfig
index 682b3d2da623..ccafcd9b4212 100644
--- a/drivers/usb/host/Kconfig
+++ b/drivers/usb/host/Kconfig
@@ -104,6 +104,14 @@ config USB_XHCI_TEGRA
 	  Say 'Y' to enable the support for the xHCI host controller
 	  found in NVIDIA Tegra124 and later SoCs.
 
+config USB_XHCI_EXYNOS
+	tristate "xHCI support for Samsung Exynos SoC Series"
+	depends on USB_XHCI_PLATFORM
+	depends on ARCH_EXYNOS || COMPILE_TEST
+	help
+	  Say 'Y' to enable the support for the xHCI host controller
+	  found in Samsung Exynos SoCs.
+
 endif # USB_XHCI_HCD
 
 config USB_EHCI_BRCMSTB
diff --git a/drivers/usb/host/Makefile b/drivers/usb/host/Makefile
index 2948983618fb..300f22b6eb1b 100644
--- a/drivers/usb/host/Makefile
+++ b/drivers/usb/host/Makefile
@@ -86,3 +86,4 @@ obj-$(CONFIG_USB_HCD_SSB)	+= ssb-hcd.o
 obj-$(CONFIG_USB_FOTG210_HCD)	+= fotg210-hcd.o
 obj-$(CONFIG_USB_MAX3421_HCD)	+= max3421-hcd.o
 obj-$(CONFIG_USB_XEN_HCD)	+= xen-hcd.o
+obj-$(CONFIG_USB_XHCI_EXYNOS)	+= xhci-exynos.o
diff --git a/drivers/usb/host/xhci-exynos.c b/drivers/usb/host/xhci-exynos.c
new file mode 100644
index 000000000000..5318a51ac5ee
--- /dev/null
+++ b/drivers/usb/host/xhci-exynos.c
@@ -0,0 +1,775 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * xhci-exynos.c - xHCI host controller driver platform Bus Glue for Exynos.
+ *
+ * Copyright (C) 2022 Samsung Electronics Incorporated - http://www.samsung.com
+ * Author: Daehwan Jung <dh10.jung@samsung.com>
+ *
+ * A lot of code borrowed from the Linux xHCI driver.
+ */
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+
+#include "xhci.h"
+#include "xhci-plat.h"
+
+/* EXYNOS uram memory map */
+#define EXYNOS_URAM_ABOX_EVT_RING_ADDR	0x02a00000
+#define EXYNOS_URAM_ISOC_OUT_RING_ADDR	0x02a01000
+#define EXYNOS_URAM_ISOC_IN_RING_ADDR	0x02a02000
+#define EXYNOS_URAM_DEVICE_CTX_ADDR	0x02a03000
+#define EXYNOS_URAM_DCBAA_ADDR		0x02a03880
+#define EXYNOS_URAM_ABOX_ERST_SEG_ADDR	0x02a03C80
+#define EXYNOS_URAM_CTX_SIZE		2112
+
+int xhci_exynos_register_vendor_ops(void);
+
+struct xhci_hcd_exynos {
+	struct	xhci_intr_reg __iomem *ir_set_audio;
+
+	struct xhci_ring	*event_ring_audio;
+	struct xhci_erst	erst_audio;
+
+	struct device		*dev;
+	struct usb_hcd		*hcd;
+	struct usb_hcd		*shared_hcd;
+
+	struct wakeup_source *main_wakelock; /* Wakelock for HS HCD */
+	struct wakeup_source *shared_wakelock; /* Wakelock for SS HCD */
+
+	u32 in_ep;
+	u32 out_ep;
+	u32 in_deq;
+	u32 out_deq;
+
+	/* This flag is used to check first allocation for URAM */
+	bool			exynos_uram_ctx_alloc;
+	bool			exynos_uram_isoc_out_alloc;
+	bool			exynos_uram_isoc_in_alloc;
+
+	unsigned long long	quirks;
+};
+
+static const struct dev_pm_ops xhci_exynos_pm_ops;
+
+static struct xhci_vendor_ops ops;
+static void xhci_exynos_parse_endpoint(struct xhci_hcd *xhci, struct usb_device *udev,
+		struct usb_endpoint_descriptor *desc, struct xhci_container_ctx *ctx);
+static void xhci_exynos_free_event_ring(struct xhci_hcd *xhci);
+static struct xhci_segment *xhci_segment_alloc_uram_ep(struct xhci_hcd *xhci,
+					       unsigned int cycle_state,
+					       unsigned int max_packet,
+					       gfp_t flags, int seg_num,
+					       u32 endpoint_type);
+static struct xhci_ring *xhci_ring_alloc_uram(struct xhci_hcd *xhci,
+		unsigned int num_segs, unsigned int cycle_state,
+		enum xhci_ring_type type, unsigned int max_packet, gfp_t flags,
+		u32 endpoint_type);
+static void xhci_exynos_ring_free(struct xhci_hcd *xhci, struct xhci_ring *ring);
+static int xhci_exynos_alloc_event_ring(struct xhci_hcd *xhci, gfp_t flags);
+
+int xhci_exynos_register_vendor_ops(void)
+{
+	return xhci_plat_register_vendor_ops(&ops);
+}
+EXPORT_SYMBOL_GPL(xhci_exynos_register_vendor_ops);
+
+static void xhci_exynos_quirks(struct device *dev, struct xhci_hcd *xhci)
+{
+	struct xhci_plat_priv *priv = xhci_to_priv(xhci);
+	struct xhci_hcd_exynos *xhci_exynos = priv->vendor_priv;
+
+	xhci->quirks |= XHCI_PLAT | xhci_exynos->quirks;
+}
+
+/* called during probe() after chip reset completes */
+static int xhci_exynos_setup(struct usb_hcd *hcd)
+{
+	int ret;
+	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
+
+	ret = xhci_gen_setup(hcd, xhci_exynos_quirks);
+	xhci_exynos_alloc_event_ring(xhci, GFP_KERNEL);
+
+	return ret;
+}
+
+static void xhci_exynos_usb_offload_enable_event_ring(struct xhci_hcd *xhci)
+{
+	struct xhci_plat_priv *priv = xhci_to_priv(xhci);
+	struct xhci_hcd_exynos *xhci_exynos = priv->vendor_priv;
+
+	u32 temp;
+	u64 temp_64;
+
+	temp_64 = xhci_read_64(xhci, &xhci_exynos->ir_set_audio->erst_dequeue);
+	temp_64 &= ~ERST_PTR_MASK;
+	xhci_info(xhci,	"ERST2 deq = 64'h%0lx", (unsigned long) temp_64);
+
+	xhci_info(xhci, "// [USB Audio] Set the interrupt modulation register");
+	temp = readl(&xhci_exynos->ir_set_audio->irq_control);
+	temp &= ~ER_IRQ_INTERVAL_MASK;
+	temp |= (u32)160;
+	writel(temp, &xhci_exynos->ir_set_audio->irq_control);
+
+	temp = readl(&xhci_exynos->ir_set_audio->irq_pending);
+	xhci_info(xhci, "// [USB Audio] Enabling event ring interrupter %p by writing 0x%x to irq_pending",
+			xhci_exynos->ir_set_audio, (unsigned int) ER_IRQ_ENABLE(temp));
+	writel(ER_IRQ_ENABLE(temp), &xhci_exynos->ir_set_audio->irq_pending);
+}
+
+static int xhci_exynos_start(struct usb_hcd *hcd)
+{
+	struct xhci_hcd *xhci;
+	int ret;
+
+	ret = xhci_run(hcd);
+
+	xhci = hcd_to_xhci(hcd);
+	xhci_exynos_usb_offload_enable_event_ring(xhci);
+
+	return ret;
+}
+
+static int xhci_exynos_add_endpoint(struct usb_hcd *hcd, struct usb_device *udev,
+		struct usb_host_endpoint *ep)
+{
+	int ret;
+	struct xhci_hcd *xhci;
+	struct xhci_virt_device *virt_dev;
+
+	ret = xhci_add_endpoint(hcd, udev, ep);
+
+	if (!ret && udev->slot_id) {
+		xhci = hcd_to_xhci(hcd);
+		virt_dev = xhci->devs[udev->slot_id];
+		xhci_exynos_parse_endpoint(xhci, udev, &ep->desc, virt_dev->out_ctx);
+	}
+
+	return ret;
+}
+
+static int xhci_exynos_address_device(struct usb_hcd *hcd, struct usb_device *udev)
+{
+	int ret;
+
+	ret = xhci_address_device(hcd, udev);
+
+	/* TODO: store and pass hw info to Co-Processor here*/
+
+	return ret;
+}
+
+static int xhci_exynos_wake_lock(struct xhci_hcd_exynos *xhci_exynos,
+				   int is_main_hcd, int is_lock)
+{
+	struct usb_hcd	*hcd = xhci_exynos->hcd;
+	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
+	struct wakeup_source *main_wakelock, *shared_wakelock;
+
+	main_wakelock = xhci_exynos->main_wakelock;
+	shared_wakelock = xhci_exynos->shared_wakelock;
+
+	if (xhci->xhc_state & XHCI_STATE_REMOVING)
+		return -ESHUTDOWN;
+
+	if (is_lock) {
+		if (is_main_hcd)
+			__pm_stay_awake(main_wakelock);
+		else
+			__pm_stay_awake(shared_wakelock);
+	} else {
+		if (is_main_hcd)
+			__pm_relax(main_wakelock);
+		else
+			__pm_relax(shared_wakelock);
+	}
+
+	return 0;
+}
+
+static int xhci_exynos_bus_suspend(struct usb_hcd *hcd)
+{
+	struct xhci_plat_priv *priv = hcd_to_xhci_priv(hcd);
+	struct xhci_hcd_exynos *xhci_exynos = priv->vendor_priv;
+	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
+
+
+	int ret, main_hcd;
+
+	if (hcd == xhci->main_hcd)
+		main_hcd = 1;
+	else
+		main_hcd = 0;
+
+	ret = xhci_bus_suspend(hcd);
+	xhci_exynos_wake_lock(xhci_exynos, main_hcd, 0);
+
+	return ret;
+}
+
+static int xhci_exynos_bus_resume(struct usb_hcd *hcd)
+{
+	struct xhci_plat_priv *priv = hcd_to_xhci_priv(hcd);
+	struct xhci_hcd_exynos *xhci_exynos = priv->vendor_priv;
+	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
+
+	int ret, main_hcd;
+
+	if (hcd == xhci->main_hcd)
+		main_hcd = 1;
+	else
+		main_hcd = 0;
+
+	ret = xhci_bus_resume(hcd);
+	xhci_exynos_wake_lock(xhci_exynos, main_hcd, 1);
+
+	return ret;
+}
+
+const struct xhci_driver_overrides xhci_exynos_overrides = {
+	.reset = xhci_exynos_setup,
+	.start = xhci_exynos_start,
+	.add_endpoint = xhci_exynos_add_endpoint,
+	.address_device = xhci_exynos_address_device,
+	.bus_suspend = xhci_exynos_bus_suspend,
+	.bus_resume = xhci_exynos_bus_resume,
+};
+
+static int xhci_exynos_vendor_init(struct xhci_hcd *xhci, struct device *dev)
+{
+	struct usb_hcd		*hcd;
+	struct xhci_hcd_exynos	*xhci_exynos;
+	struct xhci_plat_priv *priv;
+	struct wakeup_source	*main_wakelock, *shared_wakelock;
+
+	xhci_plat_override_driver(&xhci_exynos_overrides);
+	dev->driver->pm = &xhci_exynos_pm_ops;
+
+	main_wakelock = wakeup_source_register(dev, dev_name(dev));
+	__pm_stay_awake(main_wakelock);
+
+	/* Initialization shared wakelock for SS HCD */
+	shared_wakelock = wakeup_source_register(dev, dev_name(dev));
+	__pm_stay_awake(shared_wakelock);
+
+	hcd = xhci->main_hcd;
+
+	priv = hcd_to_xhci_priv(hcd);
+	xhci_exynos = priv->vendor_priv;
+	xhci_exynos->dev = dev;
+	xhci_exynos->main_wakelock = main_wakelock;
+	xhci_exynos->shared_wakelock = shared_wakelock;
+
+	return 0;
+}
+
+static void xhci_exynos_vendor_cleanup(struct xhci_hcd *xhci)
+{
+	xhci_exynos_free_event_ring(xhci);
+}
+
+static bool xhci_exynos_is_usb_offload_enabled(struct xhci_hcd *xhci,
+		struct xhci_virt_device *virt_dev, unsigned int ep_index)
+{
+	/* TODO */
+	return true;
+}
+
+static struct xhci_device_context_array *xhci_exynos_alloc_dcbaa(
+		struct xhci_hcd *xhci, gfp_t flags)
+{
+	int i;
+
+	xhci->dcbaa = ioremap(EXYNOS_URAM_DCBAA_ADDR,
+					sizeof(*xhci->dcbaa));
+	if (!xhci->dcbaa)
+		return NULL;
+	/* Clear DCBAA */
+	for (i = 0; i < MAX_HC_SLOTS; i++)
+		xhci->dcbaa->dev_context_ptrs[i] = 0x0;
+
+	xhci->dcbaa->dma = EXYNOS_URAM_DCBAA_ADDR;
+
+	return xhci->dcbaa;
+}
+
+static void xhci_exynos_free_dcbaa(struct xhci_hcd *xhci)
+{
+	iounmap(xhci->dcbaa);
+	xhci->dcbaa = NULL;
+}
+
+static struct xhci_ring *xhci_exynos_alloc_transfer_ring(struct xhci_hcd *xhci, u32 endpoint_type,
+			enum xhci_ring_type ring_type, unsigned int max_packet, gfp_t mem_flags)
+{
+	struct xhci_plat_priv *priv = xhci_to_priv(xhci);
+	struct xhci_hcd_exynos *xhci_exynos = priv->vendor_priv;
+	/* If URAM is not allocated, it try to allocate from URAM */
+	if (xhci_exynos->exynos_uram_isoc_out_alloc == 0 && endpoint_type == ISOC_OUT_EP) {
+		xhci_exynos->exynos_uram_isoc_out_alloc = 1;
+		return xhci_ring_alloc_uram(xhci, 1, 1, ring_type, max_packet, mem_flags,
+						endpoint_type);
+	} else if (xhci_exynos->exynos_uram_isoc_in_alloc == 0 && endpoint_type == ISOC_IN_EP) {
+		xhci_exynos->exynos_uram_isoc_in_alloc = 1;
+		return xhci_ring_alloc_uram(xhci, 1, 1, ring_type, max_packet, mem_flags,
+						endpoint_type);
+	} else
+		return xhci_ring_alloc(xhci, 2, 1, ring_type, max_packet, mem_flags);
+}
+
+static void xhci_exynos_free_transfer_ring(struct xhci_hcd *xhci, struct xhci_ring *ring,
+						unsigned int ep_index)
+{
+	xhci_exynos_ring_free(xhci, ring);
+}
+
+static void xhci_exynos_alloc_container_ctx(struct xhci_hcd *xhci, struct xhci_container_ctx *ctx,
+						int type, gfp_t flags)
+{
+	struct xhci_plat_priv *priv = xhci_to_priv(xhci);
+	struct xhci_hcd_exynos *xhci_exynos = priv->vendor_priv;
+
+	if (type != XHCI_CTX_TYPE_INPUT && xhci_exynos->exynos_uram_ctx_alloc == 0) {
+		/* Only first Device Context uses URAM */
+		int i;
+
+		ctx->bytes = ioremap(EXYNOS_URAM_DEVICE_CTX_ADDR, EXYNOS_URAM_CTX_SIZE);
+		if (!ctx->bytes)
+			return;
+
+		for (i = 0; i < EXYNOS_URAM_CTX_SIZE; i++)
+			ctx->bytes[i] = 0;
+
+		ctx->dma = EXYNOS_URAM_DEVICE_CTX_ADDR;
+
+		xhci_exynos->exynos_uram_ctx_alloc = 1;
+	} else {
+		ctx->bytes = dma_pool_zalloc(xhci->device_pool, flags, &ctx->dma);
+		if (!ctx->bytes)
+			return;
+	}
+}
+
+static void xhci_exynos_free_container_ctx(struct xhci_hcd *xhci, struct xhci_container_ctx *ctx)
+{
+	/* Ignore dma_pool_free if it is allocated from URAM */
+	if (ctx->dma != EXYNOS_URAM_DEVICE_CTX_ADDR)
+		dma_pool_free(xhci->device_pool, ctx->bytes, ctx->dma);
+}
+
+static int xhci_exynos_sync_dev_ctx(struct xhci_hcd *xhci, unsigned int slot_id)
+{
+	struct xhci_plat_priv *priv = xhci_to_priv(xhci);
+	struct xhci_hcd_exynos *xhci_exynos = priv->vendor_priv;
+	struct xhci_virt_device *virt_dev;
+	struct xhci_slot_ctx *slot_ctx;
+
+	int i;
+	int last_ep;
+	int last_ep_ctx = 31;
+
+	virt_dev = xhci->devs[slot_id];
+	slot_ctx = xhci_get_slot_ctx(xhci, virt_dev->in_ctx);
+
+	last_ep = LAST_CTX_TO_EP_NUM(le32_to_cpu(slot_ctx->dev_info));
+
+	if (last_ep < 31)
+		last_ep_ctx = last_ep + 1;
+
+	for (i = 0; i < last_ep_ctx; ++i) {
+		unsigned int epaddr = xhci_get_endpoint_address(i);
+		struct xhci_ep_ctx *ep_ctx = xhci_get_ep_ctx(xhci, virt_dev->out_ctx, i);
+
+		if (epaddr == xhci_exynos->in_ep)
+			xhci_exynos->in_deq = ep_ctx->deq;
+		else if (epaddr == xhci_exynos->out_ep)
+			xhci_exynos->out_deq = ep_ctx->deq;
+	}
+
+	return 0;
+}
+static struct xhci_vendor_ops ops = {
+	.vendor_init = xhci_exynos_vendor_init,
+	.vendor_cleanup = xhci_exynos_vendor_cleanup,
+	.is_usb_offload_enabled = xhci_exynos_is_usb_offload_enabled,
+	.alloc_dcbaa = xhci_exynos_alloc_dcbaa,
+	.free_dcbaa = xhci_exynos_free_dcbaa,
+	.alloc_transfer_ring = xhci_exynos_alloc_transfer_ring,
+	.free_transfer_ring = xhci_exynos_free_transfer_ring,
+	.alloc_container_ctx = xhci_exynos_alloc_container_ctx,
+	.free_container_ctx = xhci_exynos_free_container_ctx,
+	.sync_dev_ctx = xhci_exynos_sync_dev_ctx,
+};
+
+
+static void xhci_exynos_parse_endpoint(struct xhci_hcd *xhci, struct usb_device *udev,
+		struct usb_endpoint_descriptor *desc, struct xhci_container_ctx *ctx)
+{
+	struct xhci_plat_priv *priv = xhci_to_priv(xhci);
+	struct xhci_hcd_exynos *xhci_exynos = priv->vendor_priv;
+	struct usb_endpoint_descriptor *d = desc;
+
+	if ((d->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) ==
+				USB_ENDPOINT_XFER_ISOC) {
+		if (d->bEndpointAddress & USB_ENDPOINT_DIR_MASK)
+			xhci_exynos->in_ep = d->bEndpointAddress;
+		else
+			xhci_exynos->out_ep = d->bEndpointAddress;
+	}
+}
+
+static void xhci_exynos_segment_free_skip(struct xhci_hcd *xhci, struct xhci_segment *seg)
+{
+	struct xhci_plat_priv *priv = xhci_to_priv(xhci);
+	struct xhci_hcd_exynos *xhci_exynos = priv->vendor_priv;
+
+	if (seg->trbs) {
+		/* Check URAM address for memory free */
+		if (seg->dma == EXYNOS_URAM_ABOX_EVT_RING_ADDR) {
+			iounmap(seg->trbs);
+		} else if (seg->dma == EXYNOS_URAM_ISOC_OUT_RING_ADDR) {
+			xhci_exynos->exynos_uram_isoc_out_alloc = 0;
+			iounmap(seg->trbs);
+		} else if (seg->dma == EXYNOS_URAM_ISOC_IN_RING_ADDR) {
+			xhci_exynos->exynos_uram_isoc_in_alloc = 0;
+			iounmap(seg->trbs);
+		} else
+			dma_pool_free(xhci->segment_pool, seg->trbs, seg->dma);
+
+		seg->trbs = NULL;
+	}
+	kfree(seg->bounce_buf);
+	kfree(seg);
+}
+
+static void xhci_exynos_free_segments_for_ring(struct xhci_hcd *xhci,
+				struct xhci_segment *first)
+{
+	struct xhci_segment *seg;
+
+	seg = first->next;
+
+	while (seg != first) {
+		struct xhci_segment *next = seg->next;
+
+		xhci_exynos_segment_free_skip(xhci, seg);
+		seg = next;
+	}
+	xhci_exynos_segment_free_skip(xhci, first);
+}
+
+static void xhci_exynos_ring_free(struct xhci_hcd *xhci, struct xhci_ring *ring)
+{
+	if (!ring)
+		return;
+
+	if (ring->first_seg) {
+		if (ring->type == TYPE_STREAM)
+			xhci_remove_stream_mapping(ring);
+
+		xhci_exynos_free_segments_for_ring(xhci, ring->first_seg);
+	}
+
+	kfree(ring);
+}
+
+static void xhci_exynos_free_event_ring(struct xhci_hcd *xhci)
+{
+	struct xhci_plat_priv *priv = xhci_to_priv(xhci);
+	struct xhci_hcd_exynos *xhci_exynos = priv->vendor_priv;
+
+	xhci_exynos_ring_free(xhci, xhci_exynos->event_ring_audio);
+}
+
+static void xhci_exynos_set_hc_event_deq_audio(struct xhci_hcd *xhci)
+{
+	struct xhci_plat_priv *priv = xhci_to_priv(xhci);
+	struct xhci_hcd_exynos *xhci_exynos = priv->vendor_priv;
+
+	u64 temp;
+	dma_addr_t deq;
+
+	deq = xhci_trb_virt_to_dma(xhci_exynos->event_ring_audio->deq_seg,
+			xhci_exynos->event_ring_audio->dequeue);
+	if (deq == 0 && !in_interrupt())
+		xhci_warn(xhci, "WARN something wrong with SW event ring "
+				"dequeue ptr.\n");
+	/* Update HC event ring dequeue pointer */
+	temp = xhci_read_64(xhci, &xhci_exynos->ir_set_audio->erst_dequeue);
+	temp &= ERST_PTR_MASK;
+	/* Don't clear the EHB bit (which is RW1C) because
+	 * there might be more events to service.
+	 */
+	temp &= ~ERST_EHB;
+	xhci_info(xhci,	"//[%s] Write event ring dequeue pointer = 0x%llx, "
+			"preserving EHB bit", __func__,
+			((u64) deq & (u64) ~ERST_PTR_MASK) | temp);
+	xhci_write_64(xhci, ((u64) deq & (u64) ~ERST_PTR_MASK) | temp,
+			&xhci_exynos->ir_set_audio->erst_dequeue);
+
+}
+
+
+
+static int xhci_exynos_alloc_event_ring(struct xhci_hcd *xhci, gfp_t flags)
+{
+	struct xhci_plat_priv *priv = xhci_to_priv(xhci);
+	struct xhci_hcd_exynos *xhci_exynos = priv->vendor_priv;
+
+	if (xhci_check_trb_in_td_math(xhci) < 0)
+		goto fail;
+
+	xhci_exynos->event_ring_audio = xhci_ring_alloc(xhci, ERST_NUM_SEGS, 1,
+						TYPE_EVENT, 0, flags);
+	/* Set the event ring dequeue address */
+	xhci_exynos_set_hc_event_deq_audio(xhci);
+
+	return 0;
+fail:
+	return -1;
+}
+
+static struct xhci_segment *xhci_segment_alloc_uram(struct xhci_hcd *xhci,
+					       unsigned int cycle_state,
+					       unsigned int max_packet,
+					       gfp_t flags)
+{
+	struct xhci_segment *seg;
+	dma_addr_t	dma;
+	int		i;
+	struct device *dev = xhci_to_hcd(xhci)->self.sysdev;
+
+	seg = kzalloc_node(sizeof(*seg), flags, dev_to_node(dev));
+	if (!seg)
+		return NULL;
+
+	seg->trbs = ioremap(EXYNOS_URAM_ABOX_EVT_RING_ADDR, TRB_SEGMENT_SIZE);
+	if (!seg->trbs)
+		return NULL;
+
+	dma = EXYNOS_URAM_ABOX_EVT_RING_ADDR;
+
+	if (max_packet) {
+		seg->bounce_buf = kzalloc_node(max_packet, flags,
+					dev_to_node(dev));
+		if (!seg->bounce_buf) {
+			dma_pool_free(xhci->segment_pool, seg->trbs, dma);
+			kfree(seg);
+			return NULL;
+		}
+	}
+	/* If the cycle state is 0, set the cycle bit to 1 for all the TRBs */
+	if (cycle_state == 0) {
+		for (i = 0; i < TRBS_PER_SEGMENT; i++)
+			seg->trbs[i].link.control |= cpu_to_le32(TRB_CYCLE);
+	}
+	seg->dma = dma;
+	seg->next = NULL;
+
+	return seg;
+}
+
+static struct xhci_segment *xhci_segment_alloc_uram_ep(struct xhci_hcd *xhci,
+					       unsigned int cycle_state,
+					       unsigned int max_packet,
+					       gfp_t flags, int seg_num,
+					       u32 endpoint_type)
+{
+	struct xhci_segment *seg;
+	dma_addr_t	dma;
+	int		i;
+	struct device *dev = xhci_to_hcd(xhci)->self.sysdev;
+
+	seg = kzalloc_node(sizeof(*seg), flags, dev_to_node(dev));
+	if (!seg)
+		return NULL;
+
+	if (seg_num != 0) {
+		/* Support just one segment */
+		xhci_err(xhci, "%s : Unexpected SEG NUMBER!\n", __func__);
+		return NULL;
+	}
+
+	if (endpoint_type == ISOC_OUT_EP) {
+		seg->trbs = ioremap(EXYNOS_URAM_ISOC_OUT_RING_ADDR,
+							TRB_SEGMENT_SIZE);
+		if (!seg->trbs)
+			return NULL;
+
+		dma = EXYNOS_URAM_ISOC_OUT_RING_ADDR;
+	} else if (endpoint_type == ISOC_IN_EP) {
+		seg->trbs = ioremap(EXYNOS_URAM_ISOC_IN_RING_ADDR,
+							TRB_SEGMENT_SIZE);
+		if (!seg->trbs)
+			return NULL;
+
+		dma = EXYNOS_URAM_ISOC_IN_RING_ADDR;
+	} else {
+		xhci_err(xhci, "%s : Unexpected EP Type!\n", __func__);
+		return NULL;
+	}
+
+	for (i = 0; i < 256; i++) {
+		seg->trbs[i].link.segment_ptr = 0;
+		seg->trbs[i].link.intr_target = 0;
+		seg->trbs[i].link.control = 0;
+	}
+
+
+	if (max_packet) {
+		seg->bounce_buf = kzalloc_node(max_packet, flags,
+					dev_to_node(dev));
+		if (!seg->bounce_buf) {
+			dma_pool_free(xhci->segment_pool, seg->trbs, dma);
+			kfree(seg);
+			return NULL;
+		}
+	}
+	/* If the cycle state is 0, set the cycle bit to 1 for all the TRBs */
+	if (cycle_state == 0) {
+		for (i = 0; i < TRBS_PER_SEGMENT; i++)
+			seg->trbs[i].link.control |= cpu_to_le32(TRB_CYCLE);
+	}
+	seg->dma = dma;
+	seg->next = NULL;
+
+	return seg;
+}
+
+static int xhci_alloc_segments_for_ring_uram(struct xhci_hcd *xhci,
+		struct xhci_segment **first, struct xhci_segment **last,
+		unsigned int num_segs, unsigned int cycle_state,
+		enum xhci_ring_type type, unsigned int max_packet, gfp_t flags,
+		u32 endpoint_type)
+{
+	struct xhci_segment *prev;
+	bool chain_links = false;
+
+	if (type == TYPE_ISOC) {
+		prev = xhci_segment_alloc_uram_ep(xhci, cycle_state,
+							max_packet, flags, 0,
+							endpoint_type);
+	} else if (type == TYPE_EVENT) {
+		prev = xhci_segment_alloc_uram(xhci, cycle_state, max_packet, flags);
+	} else {
+		xhci_err(xhci, "Unexpected TYPE for URAM allocation!\n");
+		return -ENOMEM;
+	}
+
+	if (!prev)
+		return -ENOMEM;
+	num_segs--;
+
+	*first = prev;
+	while (num_segs > 0) {
+		struct xhci_segment *next = NULL;
+
+		if (type == TYPE_ISOC) {
+			prev = xhci_segment_alloc_uram_ep(xhci, cycle_state,
+							max_packet, flags, 1,
+							endpoint_type);
+		} else if (type == TYPE_EVENT) {
+			next = xhci_segment_alloc_uram(xhci, cycle_state,
+							max_packet, flags);
+		} else {
+			xhci_err(xhci, "Unexpected TYPE for URAM alloc(multi)!\n");
+			return -ENOMEM;
+		}
+
+		if (!next) {
+			prev = *first;
+			while (prev) {
+				next = prev->next;
+				xhci_segment_free(xhci, prev);
+				prev = next;
+			}
+			return -ENOMEM;
+		}
+		xhci_link_segments(prev, next, type, chain_links);
+
+		prev = next;
+		num_segs--;
+	}
+	xhci_link_segments(prev, *first, type, chain_links);
+	*last = prev;
+
+	return 0;
+}
+
+static struct xhci_ring *xhci_ring_alloc_uram(struct xhci_hcd *xhci,
+		unsigned int num_segs, unsigned int cycle_state,
+		enum xhci_ring_type type, unsigned int max_packet, gfp_t flags,
+		u32 endpoint_type)
+{
+	struct xhci_ring	*ring;
+	int ret;
+	struct device *dev = xhci_to_hcd(xhci)->self.sysdev;
+
+	ring = kzalloc_node(sizeof(*ring), flags, dev_to_node(dev));
+	if (!ring)
+		return NULL;
+
+	ring->num_segs = num_segs;
+	ring->bounce_buf_len = max_packet;
+	INIT_LIST_HEAD(&ring->td_list);
+	ring->type = type;
+	if (num_segs == 0)
+		return ring;
+
+	ret = xhci_alloc_segments_for_ring_uram(xhci, &ring->first_seg,
+			&ring->last_seg, num_segs, cycle_state, type,
+			max_packet, flags, endpoint_type);
+	if (ret)
+		goto fail;
+
+	/* Only event ring does not use link TRB */
+	if (type != TYPE_EVENT) {
+		/* See section 4.9.2.1 and 6.4.4.1 */
+		ring->last_seg->trbs[TRBS_PER_SEGMENT - 1].link.control |=
+			cpu_to_le32(LINK_TOGGLE);
+	}
+	xhci_initialize_ring_info(ring, cycle_state);
+
+	return ring;
+
+fail:
+	kfree(ring);
+	return NULL;
+}
+
+static int xhci_exynos_suspend(struct device *dev)
+{
+	struct usb_hcd	*hcd = dev_get_drvdata(dev);
+	struct xhci_hcd	*xhci = hcd_to_xhci(hcd);
+
+	/* TODO: AP sleep scenario*/
+
+	return xhci_suspend(xhci, device_may_wakeup(dev));
+}
+
+static int xhci_exynos_resume(struct device *dev)
+{
+	struct usb_hcd	*hcd = dev_get_drvdata(dev);
+	struct xhci_hcd	*xhci = hcd_to_xhci(hcd);
+	int ret;
+
+	/* TODO: AP resume scenario*/
+
+	ret = xhci_resume(xhci, 0);
+	if (ret)
+		return ret;
+
+	pm_runtime_disable(dev);
+	pm_runtime_set_active(dev);
+	pm_runtime_enable(dev);
+
+	return 0;
+}
+
+static const struct dev_pm_ops xhci_exynos_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(xhci_exynos_suspend, xhci_exynos_resume)
+};
+
+MODULE_DESCRIPTION("xHCI Exynos Host Controller Driver");
+MODULE_LICENSE("GPL");
-- 
2.31.1

Re: [PATCH RFC v5 5/6] usb: host: add xhci-exynos driver

[Krzysztof Kozlowski]

On 06/05/2022 08:31, Daehwan Jung wrote:
> This driver is for Samsung Exynos xHCI host conroller. It works based on

https://elixir.bootlin.com/linux/v5.17.1/source/Documentation/process/submitting-patches.rst#L95

> xhci platform driver and extends functions by xhci hooks and overrides.
> Vendor ops(xhci hooks) should be mapped before probing driver.
> It overrides functions of hc driver on vendor init.
> 
> It supports USB Audio offload with Co-processor. It only cares DCBAA,
> Device Context, Transfer Ring, Event Ring, and ERST. They are allocated
> on specific address with xhci hooks. Co-processor could use them directly
> without xhci driver after then.
> 
> Signed-off-by: Daehwan Jung <dh10.jung@samsung.com>
> ---
>  drivers/usb/host/Kconfig       |   8 +
>  drivers/usb/host/Makefile      |   1 +
>  drivers/usb/host/xhci-exynos.c | 775 +++++++++++++++++++++++++++++++++

This is your fifth version and *it still does not compile*. Can you
compile your changes before sending them? It saves reviewer's time.

/usr/bin/aarch64-linux-gnu-ld: drivers/usb/dwc3/dwc3-exynos.o: in
function `dwc3_exynos_probe':

dwc3-exynos.c:(.text+0x470): undefined reference to
`xhci_exynos_register_vendor_ops'



>  3 files changed, 784 insertions(+)
>  create mode 100644 drivers/usb/host/xhci-exynos.c
> 
> diff --git a/drivers/usb/host/Kconfig b/drivers/usb/host/Kconfig
> index 682b3d2da623..ccafcd9b4212 100644
> --- a/drivers/usb/host/Kconfig
> +++ b/drivers/usb/host/Kconfig
> @@ -104,6 +104,14 @@ config USB_XHCI_TEGRA
>  	  Say 'Y' to enable the support for the xHCI host controller
>  	  found in NVIDIA Tegra124 and later SoCs.
>  
> +config USB_XHCI_EXYNOS
> +	tristate "xHCI support for Samsung Exynos SoC Series"

XHCI was supported before, wasn't it? If yes, this title does not make
really sense.

You need to provide proper title explaining this option.

> +	depends on USB_XHCI_PLATFORM
> +	depends on ARCH_EXYNOS || COMPILE_TEST
> +	help
> +	  Say 'Y' to enable the support for the xHCI host controller
> +	  found in Samsung Exynos SoCs.

The same.

> +
>  endif # USB_XHCI_HCD
>  
>  config USB_EHCI_BRCMSTB
> diff --git a/drivers/usb/host/Makefile b/drivers/usb/host/Makefile
> index 2948983618fb..300f22b6eb1b 100644
> --- a/drivers/usb/host/Makefile
> +++ b/drivers/usb/host/Makefile
> @@ -86,3 +86,4 @@ obj-$(CONFIG_USB_HCD_SSB)	+= ssb-hcd.o
>  obj-$(CONFIG_USB_FOTG210_HCD)	+= fotg210-hcd.o
>  obj-$(CONFIG_USB_MAX3421_HCD)	+= max3421-hcd.o
>  obj-$(CONFIG_USB_XEN_HCD)	+= xen-hcd.o
> +obj-$(CONFIG_USB_XHCI_EXYNOS)	+= xhci-exynos.o
> diff --git a/drivers/usb/host/xhci-exynos.c b/drivers/usb/host/xhci-exynos.c
> new file mode 100644
> index 000000000000..5318a51ac5ee
> --- /dev/null
> +++ b/drivers/usb/host/xhci-exynos.c
> @@ -0,0 +1,775 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * xhci-exynos.c - xHCI host controller driver platform Bus Glue for Exynos.
> + *
> + * Copyright (C) 2022 Samsung Electronics Incorporated - http://www.samsung.com
> + * Author: Daehwan Jung <dh10.jung@samsung.com>
> + *
> + * A lot of code borrowed from the Linux xHCI driver.

Then please keep original copyrights, as a derivative work.

> + */
> +#include <linux/pci.h>
> +#include <linux/platform_device.h>
> +
> +#include "xhci.h"
> +#include "xhci-plat.h"
> +
> +/* EXYNOS uram memory map */
> +#define EXYNOS_URAM_ABOX_EVT_RING_ADDR	0x02a00000

Are these SoC memory map addresses? If yes, they should not be
hard-coded in the driver.

> +#define EXYNOS_URAM_ISOC_OUT_RING_ADDR	0x02a01000
> +#define EXYNOS_URAM_ISOC_IN_RING_ADDR	0x02a02000
> +#define EXYNOS_URAM_DEVICE_CTX_ADDR	0x02a03000
> +#define EXYNOS_URAM_DCBAA_ADDR		0x02a03880
> +#define EXYNOS_URAM_ABOX_ERST_SEG_ADDR	0x02a03C80
> +#define EXYNOS_URAM_CTX_SIZE		2112
> +
> +int xhci_exynos_register_vendor_ops(void);
> +
> +struct xhci_hcd_exynos {
> +	struct	xhci_intr_reg __iomem *ir_set_audio;
> +
> +	struct xhci_ring	*event_ring_audio;
> +	struct xhci_erst	erst_audio;

Why "xHCI support for Samsung Exynos SoC Series" comes specific to
audio? Isn't XHCI related to USB, so a Universal use? Cannot XHCI driver
support mass storage?

> +
> +	struct device		*dev;
> +	struct usb_hcd		*hcd;
> +	struct usb_hcd		*shared_hcd;
> +
> +	struct wakeup_source *main_wakelock; /* Wakelock for HS HCD */
> +	struct wakeup_source *shared_wakelock; /* Wakelock for SS HCD */

None of other USB drivers use wakeloks so why is this one special?

> +
> +	u32 in_ep;
> +	u32 out_ep;
> +	u32 in_deq;
> +	u32 out_deq;
> +
> +	/* This flag is used to check first allocation for URAM */
> +	bool			exynos_uram_ctx_alloc;
> +	bool			exynos_uram_isoc_out_alloc;
> +	bool			exynos_uram_isoc_in_alloc;

This indentation is really troubling me - just few lines above, you
don't indent variables. Here you indent. You need to clean up your
driver before submitting. Run checkpatch --strict and fix all the
issues. Add const to all static variables and most of pointed memory.
Remove any inconsistencies. Remove double blank lines. Fix indentation.

Best regards,
Krzysztof

[PATCH RFC v5 6/6] usb: dwc3: dwc3-exynos: add host init

[Daehwan Jung]

This is for xHCI Host Controller driver on Exynos SOC.
It registers vendor ops before loading xhci platform driver.

Signed-off-by: Daehwan Jung <dh10.jung@samsung.com>
---
 drivers/usb/dwc3/dwc3-exynos.c | 100 ++++++++++++++++++++++++++++++++-
 1 file changed, 99 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/dwc3/dwc3-exynos.c b/drivers/usb/dwc3/dwc3-exynos.c
index 0ecf20eeceee..c22ea5cd6ab0 100644
--- a/drivers/usb/dwc3/dwc3-exynos.c
+++ b/drivers/usb/dwc3/dwc3-exynos.c
@@ -17,6 +17,12 @@
 #include <linux/of_platform.h>
 #include <linux/regulator/consumer.h>
 
+#include "core.h"
+
+#if IS_ENABLED(CONFIG_USB_XHCI_EXYNOS)
+int xhci_exynos_register_vendor_ops(void);
+#endif
+
 #define DWC3_EXYNOS_MAX_CLOCKS	4
 
 struct dwc3_exynos_driverdata {
@@ -27,6 +33,7 @@ struct dwc3_exynos_driverdata {
 
 struct dwc3_exynos {
 	struct device		*dev;
+	struct dwc3		*dwc;
 
 	const char		**clk_names;
 	struct clk		*clks[DWC3_EXYNOS_MAX_CLOCKS];
@@ -46,12 +53,81 @@ static int dwc3_exynos_remove_child(struct device *dev, void *unused)
 	return 0;
 }
 
+#if IS_ENABLED(CONFIG_USB_XHCI_EXYNOS)
+static int dwc3_exynos_host_init(struct dwc3_exynos *exynos)
+{
+	struct dwc3		*dwc = exynos->dwc;
+	struct device		*dev = exynos->dev;
+	struct platform_device	*xhci;
+	struct resource		*res;
+	struct platform_device	*dwc3_pdev = to_platform_device(dwc->dev);
+	int			ret = 0;
+
+	/* Configuration xhci resources */
+	xhci_exynos_register_vendor_ops();
+
+	res = platform_get_resource(dwc3_pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(dev, "missing memory resource\n");
+		return -ENODEV;
+	}
+	dwc->xhci_resources[0].start = res->start;
+	dwc->xhci_resources[0].end = dwc->xhci_resources[0].start +
+					DWC3_XHCI_REGS_END;
+	dwc->xhci_resources[0].flags = res->flags;
+	dwc->xhci_resources[0].name = res->name;
+
+	res = platform_get_resource(dwc3_pdev, IORESOURCE_IRQ, 0);
+	if (!res) {
+		dev_err(dev, "missing irq resource\n");
+		return -ENODEV;
+	}
+
+	dwc->xhci_resources[1].start = dwc->irq_gadget;
+	dwc->xhci_resources[1].end = dwc->irq_gadget;
+	dwc->xhci_resources[1].flags = res->flags;
+	dwc->xhci_resources[1].name = res->name;
+
+	xhci = platform_device_alloc("xhci-hcd", PLATFORM_DEVID_AUTO);
+	if (!xhci) {
+		dev_err(dwc->dev, "couldn't allocate xHCI device\n");
+		return -ENOMEM;
+	}
+
+	xhci->dev.parent	= dwc->dev;
+	ret = dma_set_mask_and_coherent(&xhci->dev, DMA_BIT_MASK(36));
+	if (ret) {
+		pr_err("xhci dma set mask ret = %d\n", ret);
+		return ret;
+	}
+
+	ret = platform_device_add_resources(xhci, dwc->xhci_resources,
+						DWC3_XHCI_RESOURCES_NUM);
+	if (ret) {
+		dev_err(dwc->dev, "couldn't add resources to xHCI device\n");
+		goto err;
+	}
+
+	ret = platform_device_add(xhci);
+	if (ret) {
+		dev_err(dwc->dev, "couldn't add xHCI device\n");
+		goto err;
+	}
+
+	return 0;
+err:
+	platform_device_put(xhci);
+	return ret;
+}
+#endif
+
 static int dwc3_exynos_probe(struct platform_device *pdev)
 {
 	struct dwc3_exynos	*exynos;
 	struct device		*dev = &pdev->dev;
-	struct device_node	*node = dev->of_node;
+	struct device_node	*node = dev->of_node, *dwc3_np;
 	const struct dwc3_exynos_driverdata *driver_data;
+	struct platform_device *dwc3_pdev;
 	int			i, ret;
 
 	exynos = devm_kzalloc(dev, sizeof(*exynos), GFP_KERNEL);
@@ -109,6 +185,12 @@ static int dwc3_exynos_probe(struct platform_device *pdev)
 		goto vdd10_err;
 	}
 
+	dwc3_np = of_get_compatible_child(node, "snps,dwc3");
+	if (!dwc3_np) {
+		dev_err(dev, "failed to find dwc3 core child!\n");
+		goto vdd33_err;
+	}
+
 	if (node) {
 		ret = of_platform_populate(node, NULL, NULL, dev);
 		if (ret) {
@@ -121,6 +203,22 @@ static int dwc3_exynos_probe(struct platform_device *pdev)
 		goto populate_err;
 	}
 
+	dwc3_pdev = of_find_device_by_node(dwc3_np);
+	exynos->dwc = platform_get_drvdata(dwc3_pdev);
+	if (!exynos->dwc) {
+		ret = -EPROBE_DEFER;
+		dev_err(dev, "failed to get dwc3 core node!\n");
+		goto populate_err;
+	}
+
+#if IS_ENABLED(CONFIG_USB_XHCI_EXYNOS)
+	/* USB host initialization. */
+	ret = dwc3_exynos_host_init(exynos);
+	if (ret) {
+		dev_err(dev, "USB host pre-initialization fail!\n");
+		goto populate_err;
+	}
+#endif
 	return 0;
 
 populate_err:
-- 
2.31.1

Re: [PATCH RFC v5 6/6] usb: dwc3: dwc3-exynos: add host init

[Krzysztof Kozlowski]

On 06/05/2022 08:31, Daehwan Jung wrote:
> This is for xHCI Host Controller driver on Exynos SOC.

https://elixir.bootlin.com/linux/v5.17.1/source/Documentation/process/submitting-patches.rst#L95

> It registers vendor ops before loading xhci platform driver.

It does not explain why do you need it, why do you do it, what is this
going to achieve or give us.

> 
> Signed-off-by: Daehwan Jung <dh10.jung@samsung.com>
> ---
>  drivers/usb/dwc3/dwc3-exynos.c | 100 ++++++++++++++++++++++++++++++++-
>  1 file changed, 99 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/dwc3/dwc3-exynos.c b/drivers/usb/dwc3/dwc3-exynos.c
> index 0ecf20eeceee..c22ea5cd6ab0 100644
> --- a/drivers/usb/dwc3/dwc3-exynos.c
> +++ b/drivers/usb/dwc3/dwc3-exynos.c
> @@ -17,6 +17,12 @@
>  #include <linux/of_platform.h>
>  #include <linux/regulator/consumer.h>
>  
> +#include "core.h"
> +
> +#if IS_ENABLED(CONFIG_USB_XHCI_EXYNOS)

This symbol does not exist at this point, so your patch does not look
like correctly ordered.

> +int xhci_exynos_register_vendor_ops(void);
> +#endif
> +
>  #define DWC3_EXYNOS_MAX_CLOCKS	4
>  
>  struct dwc3_exynos_driverdata {
> @@ -27,6 +33,7 @@ struct dwc3_exynos_driverdata {
>  
>  struct dwc3_exynos {
>  	struct device		*dev;
> +	struct dwc3		*dwc;
>  
>  	const char		**clk_names;
>  	struct clk		*clks[DWC3_EXYNOS_MAX_CLOCKS];
> @@ -46,12 +53,81 @@ static int dwc3_exynos_remove_child(struct device *dev, void *unused)
>  	return 0;
>  }
>  
> +#if IS_ENABLED(CONFIG_USB_XHCI_EXYNOS)
> +static int dwc3_exynos_host_init(struct dwc3_exynos *exynos)
> +{
> +	struct dwc3		*dwc = exynos->dwc;
> +	struct device		*dev = exynos->dev;
> +	struct platform_device	*xhci;
> +	struct resource		*res;
> +	struct platform_device	*dwc3_pdev = to_platform_device(dwc->dev);
> +	int			ret = 0;
> +
> +	/* Configuration xhci resources */
> +	xhci_exynos_register_vendor_ops();

Why this is always being called? Runtime features should not be added
like that.

> +
> +	res = platform_get_resource(dwc3_pdev, IORESOURCE_MEM, 0);
> +	if (!res) {
> +		dev_err(dev, "missing memory resource\n");
> +		return -ENODEV;
> +	}
> +	dwc->xhci_resources[0].start = res->start;
> +	dwc->xhci_resources[0].end = dwc->xhci_resources[0].start +
> +					DWC3_XHCI_REGS_END;
> +	dwc->xhci_resources[0].flags = res->flags;
> +	dwc->xhci_resources[0].name = res->name;
> +
> +	res = platform_get_resource(dwc3_pdev, IORESOURCE_IRQ, 0);
> +	if (!res) {
> +		dev_err(dev, "missing irq resource\n");
> +		return -ENODEV;
> +	}
> +
> +	dwc->xhci_resources[1].start = dwc->irq_gadget;
> +	dwc->xhci_resources[1].end = dwc->irq_gadget;
> +	dwc->xhci_resources[1].flags = res->flags;
> +	dwc->xhci_resources[1].name = res->name;
> +
> +	xhci = platform_device_alloc("xhci-hcd", PLATFORM_DEVID_AUTO);
> +	if (!xhci) {
> +		dev_err(dwc->dev, "couldn't allocate xHCI device\n");
> +		return -ENOMEM;
> +	}
> +
> +	xhci->dev.parent	= dwc->dev;

Remove any duplicates spaces/tabs which should not be in the code (no
need for indenting '=').

> +	ret = dma_set_mask_and_coherent(&xhci->dev, DMA_BIT_MASK(36));
> +	if (ret) {
> +		pr_err("xhci dma set mask ret = %d\n", ret);
> +		return ret;
> +	}
> +
> +	ret = platform_device_add_resources(xhci, dwc->xhci_resources,
> +						DWC3_XHCI_RESOURCES_NUM);

But this should be properly indented, how checkpatch asks.

> +	if (ret) {
> +		dev_err(dwc->dev, "couldn't add resources to xHCI device\n");
> +		goto err;
> +	}
> +
> +	ret = platform_device_add(xhci);
> +	if (ret) {
> +		dev_err(dwc->dev, "couldn't add xHCI device\n");
> +		goto err;
> +	}
> +
> +	return 0;
> +err:
> +	platform_device_put(xhci);
> +	return ret;
> +}
> +#endif
> +
>  static int dwc3_exynos_probe(struct platform_device *pdev)
>  {
>  	struct dwc3_exynos	*exynos;
>  	struct device		*dev = &pdev->dev;
> -	struct device_node	*node = dev->of_node;
> +	struct device_node	*node = dev->of_node, *dwc3_np;
>  	const struct dwc3_exynos_driverdata *driver_data;
> +	struct platform_device *dwc3_pdev;
>  	int			i, ret;
>  
>  	exynos = devm_kzalloc(dev, sizeof(*exynos), GFP_KERNEL);
> @@ -109,6 +185,12 @@ static int dwc3_exynos_probe(struct platform_device *pdev)
>  		goto vdd10_err;
>  	}
>  
> +	dwc3_np = of_get_compatible_child(node, "snps,dwc3");
> +	if (!dwc3_np) {
> +		dev_err(dev, "failed to find dwc3 core child!\n");

Please keep messages consistent with other, so start with capital letter
and do not shout.

> +		goto vdd33_err;
> +	}
> +
>  	if (node) {
>  		ret = of_platform_populate(node, NULL, NULL, dev);
>  		if (ret) {
> @@ -121,6 +203,22 @@ static int dwc3_exynos_probe(struct platform_device *pdev)
>  		goto populate_err;
>  	}
>  
> +	dwc3_pdev = of_find_device_by_node(dwc3_np);
> +	exynos->dwc = platform_get_drvdata(dwc3_pdev);

Driver should not poke into its child. You violate device layering here.
No, no. This is a glue driver, not a "let's do something inside DWC3"
driver.

> +	if (!exynos->dwc) {
> +		ret = -EPROBE_DEFER;
> +		dev_err(dev, "failed to get dwc3 core node!\n");

Again no reason for shouting.

> +		goto populate_err;
> +	}
> +
> +#if IS_ENABLED(CONFIG_USB_XHCI_EXYNOS)
> +	/* USB host initialization. */
> +	ret = dwc3_exynos_host_init(exynos);
> +	if (ret) {
> +		dev_err(dev, "USB host pre-initialization fail!\n");
> +		goto populate_err;
> +	}
> +#endif
>  	return 0;
>  
>  populate_err:


Best regards,
Krzysztof

Re: [PATCH RFC v5 6/6] usb: dwc3: dwc3-exynos: add host init

[Christoph Hellwig]

On Fri, May 06, 2022 at 08:45:39AM +0200, Krzysztof Kozlowski wrote:
> On 06/05/2022 08:31, Daehwan Jung wrote:
> > This is for xHCI Host Controller driver on Exynos SOC.
> 
> https://elixir.bootlin.com/linux/v5.17.1/source/Documentation/process/submitting-patches.rst#L95
> 
> > It registers vendor ops before loading xhci platform driver.
> 
> It does not explain why do you need it, why do you do it, what is this
> going to achieve or give us.

Nver mind that the whole concept if "vendor" ops doesnt make any sense
whatsoever, as I've repeatedly pointed out.  The "vendor" is completely
irrelevant for a Linux driver.

Re: [PATCH RFC v5 6/6] usb: dwc3: dwc3-exynos: add host init

[Arnd Bergmann]

On Fri, May 6, 2022 at 8:31 AM Daehwan Jung <dh10.jung@samsung.com> wrote:
>
> This is for xHCI Host Controller driver on Exynos SOC.
> It registers vendor ops before loading xhci platform driver.
>
> Signed-off-by: Daehwan Jung <dh10.jung@samsung.com>
> ---
>  drivers/usb/dwc3/dwc3-exynos.c | 100 ++++++++++++++++++++++++++++++++-
>  1 file changed, 99 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/usb/dwc3/dwc3-exynos.c b/drivers/usb/dwc3/dwc3-exynos.c
> index 0ecf20eeceee..c22ea5cd6ab0 100644
> --- a/drivers/usb/dwc3/dwc3-exynos.c
> +++ b/drivers/usb/dwc3/dwc3-exynos.c
> @@ -17,6 +17,12 @@
>  #include <linux/of_platform.h>
>  #include <linux/regulator/consumer.h>
>
> +#include "core.h"
> +
> +#if IS_ENABLED(CONFIG_USB_XHCI_EXYNOS)
> +int xhci_exynos_register_vendor_ops(void);
> +#endif

Function declarations should always be in a header file, and not guarded
by an #ifdef. This particular one is probably not needed anyway if the
driver is done correctly though, see below.

> @@ -46,12 +53,81 @@ static int dwc3_exynos_remove_child(struct device *dev, void *unused)
>         return 0;
>  }
>
> +#if IS_ENABLED(CONFIG_USB_XHCI_EXYNOS)
> +static int dwc3_exynos_host_init(struct dwc3_exynos *exynos)
> +{
> +       struct dwc3             *dwc = exynos->dwc;
> +       struct device           *dev = exynos->dev;
> +       struct platform_device  *xhci;
> +       struct resource         *res;
> +       struct platform_device  *dwc3_pdev = to_platform_device(dwc->dev);
> +       int                     ret = 0;
> +
> +       /* Configuration xhci resources */
> +       xhci_exynos_register_vendor_ops();
> +
> +       res = platform_get_resource(dwc3_pdev, IORESOURCE_MEM, 0);
> +       if (!res) {
> +               dev_err(dev, "missing memory resource\n");
> +               return -ENODEV;
> +       }
> +       dwc->xhci_resources[0].start = res->start;
> +       dwc->xhci_resources[0].end = dwc->xhci_resources[0].start +
> +                                       DWC3_XHCI_REGS_END;
> +       dwc->xhci_resources[0].flags = res->flags;
> +       dwc->xhci_resources[0].name = res->name;
> +
> +       res = platform_get_resource(dwc3_pdev, IORESOURCE_IRQ, 0);
> +       if (!res) {
> +               dev_err(dev, "missing irq resource\n");
> +               return -ENODEV;
> +       }
> +
> +       dwc->xhci_resources[1].start = dwc->irq_gadget;
> +       dwc->xhci_resources[1].end = dwc->irq_gadget;
> +       dwc->xhci_resources[1].flags = res->flags;
> +       dwc->xhci_resources[1].name = res->name;
> +
> +       xhci = platform_device_alloc("xhci-hcd", PLATFORM_DEVID_AUTO);
> +       if (!xhci) {
> +               dev_err(dwc->dev, "couldn't allocate xHCI device\n");
> +               return -ENOMEM;
> +       }
> +
> +       xhci->dev.parent        = dwc->dev;
> +       ret = dma_set_mask_and_coherent(&xhci->dev, DMA_BIT_MASK(36));
> +       if (ret) {
> +               pr_err("xhci dma set mask ret = %d\n", ret);
> +               return ret;
> +       }

This looks like you have the abstraction backwards from what normal
drivers do. If you need a specialization of a driver that already exists,
create a new driver module with a platform_driver that matches the
specialized of_device_id, and have it call into the more general driver,
do avoid having the general driver know about the specializations.

Allocating a platform_device and making it DMA capable
doesn't generally work correctly, and misses the IOMMU setup, so make
sure you have a device node for it instead and probe it from DT.

        Arnd