* [PATCH v5 1/5] i3c: master: export i3c_masterdev_type
2026-09-21 23:05 [PATCH v5 0/5] i3c: add i3cdev module to expose i3c dev in /dev Sam Agazaryan
@ 2026-09-21 23:05 ` Sam Agazaryan
2026-09-21 23:06 ` [PATCH v5 2/5] i3c: master: add i3c_for_each_dev helper Sam Agazaryan
` (3 subsequent siblings)
4 siblings, 0 replies; 7+ messages in thread
From: Sam Agazaryan @ 2026-09-21 23:05 UTC (permalink / raw)
To: linux-i3c, Alexandre Belloni, Frank Li
Cc: Greg Kroah-Hartman, Wolfram Sang, Arnd Bergmann, Adrian Hunter,
Meagan Lloyd, Vitor Soares, Oleksandr Shulzhenko,
Boris Brezillon, linux-kernel, Sam Agazaryan
From: Vitor Soares <vitor.soares@toradex.com>
Export i3c_masterdev_type so i3cdev module can verify if an i3c device
is a master.
Signed-off-by: Vitor Soares <vitor.soares@toradex.com>
Signed-off-by: Sam Agazaryan <samagazaryan@google.com>
---
drivers/i3c/internals.h | 2 ++
drivers/i3c/master.c | 3 ++-
2 files changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/i3c/internals.h b/drivers/i3c/internals.h
index 86a36b951e0d..cbc00c862104 100644
--- a/drivers/i3c/internals.h
+++ b/drivers/i3c/internals.h
@@ -11,6 +11,8 @@
#include <linux/i3c/master.h>
#include <linux/io.h>
+extern const struct device_type i3c_masterdev_type;
+
int __must_check i3c_bus_rpm_get(struct i3c_bus *bus);
void i3c_bus_rpm_put(struct i3c_bus *bus);
bool i3c_bus_rpm_ibi_allowed(struct i3c_bus *bus);
diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
index afcd7a21a3e6..e8a9f8c3041e 100644
--- a/drivers/i3c/master.c
+++ b/drivers/i3c/master.c
@@ -864,9 +864,10 @@ static void i3c_masterdev_release(struct device *dev)
i3c_master_free_i3c_dev(master->this);
}
-static const struct device_type i3c_masterdev_type = {
+const struct device_type i3c_masterdev_type = {
.groups = i3c_masterdev_groups,
};
+EXPORT_SYMBOL_GPL(i3c_masterdev_type);
static void i3c_master_shutdown(struct i3c_master_controller *master)
{
--
2.55.0.1082.g2b9226bbc0-goog
^ permalink raw reply [flat|nested] 7+ messages in thread* [PATCH v5 2/5] i3c: master: add i3c_for_each_dev helper
2026-09-21 23:05 [PATCH v5 0/5] i3c: add i3cdev module to expose i3c dev in /dev Sam Agazaryan
2026-09-21 23:05 ` [PATCH v5 1/5] i3c: master: export i3c_masterdev_type Sam Agazaryan
@ 2026-09-21 23:06 ` Sam Agazaryan
2026-09-21 23:06 ` [PATCH v5 3/5] i3c: use actual_len for read transfers Sam Agazaryan
` (2 subsequent siblings)
4 siblings, 0 replies; 7+ messages in thread
From: Sam Agazaryan @ 2026-09-21 23:06 UTC (permalink / raw)
To: linux-i3c, Alexandre Belloni, Frank Li
Cc: Greg Kroah-Hartman, Wolfram Sang, Arnd Bergmann, Adrian Hunter,
Meagan Lloyd, Vitor Soares, Oleksandr Shulzhenko,
Boris Brezillon, linux-kernel, Sam Agazaryan
From: Vitor Soares <vitor.soares@toradex.com>
Introduce i3c_for_each_dev(), an i3c device iterator for use by i3cdev.
Signed-off-by: Vitor Soares <vitor.soares@toradex.com>
Signed-off-by: Sam Agazaryan <samagazaryan@google.com>
---
drivers/i3c/internals.h | 2 ++
drivers/i3c/master.c | 6 ++++++
2 files changed, 8 insertions(+)
diff --git a/drivers/i3c/internals.h b/drivers/i3c/internals.h
index cbc00c862104..3c53a5108b81 100644
--- a/drivers/i3c/internals.h
+++ b/drivers/i3c/internals.h
@@ -79,4 +79,6 @@ static inline struct i3c_master_controller *i3c_bus_to_i3c_master(struct i3c_bus
return container_of(i3cbus, struct i3c_master_controller, bus);
}
+int i3c_for_each_dev(void *data, int (*fn)(struct device *, void *));
+
#endif /* I3C_INTERNAL_H */
diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
index e8a9f8c3041e..07540ea73aec 100644
--- a/drivers/i3c/master.c
+++ b/drivers/i3c/master.c
@@ -4011,6 +4011,12 @@ void i3c_dev_free_ibi_locked(struct i3c_dev_desc *dev)
}
EXPORT_SYMBOL_GPL(i3c_dev_free_ibi_locked);
+int i3c_for_each_dev(void *data, int (*fn)(struct device *, void *))
+{
+ return bus_for_each_dev(&i3c_bus_type, NULL, data, fn);
+}
+EXPORT_SYMBOL_GPL(i3c_for_each_dev);
+
static int __init i3c_init(void)
{
int res;
--
2.55.0.1082.g2b9226bbc0-goog
^ permalink raw reply [flat|nested] 7+ messages in thread* [PATCH v5 3/5] i3c: use actual_len for read transfers
2026-09-21 23:05 [PATCH v5 0/5] i3c: add i3cdev module to expose i3c dev in /dev Sam Agazaryan
2026-09-21 23:05 ` [PATCH v5 1/5] i3c: master: export i3c_masterdev_type Sam Agazaryan
2026-09-21 23:06 ` [PATCH v5 2/5] i3c: master: add i3c_for_each_dev helper Sam Agazaryan
@ 2026-09-21 23:06 ` Sam Agazaryan
2026-09-24 11:53 ` Adrian Hunter
2026-09-21 23:06 ` [PATCH v5 4/5] i3c: add i3cdev module to expose i3c dev in /dev Sam Agazaryan
2026-09-21 23:06 ` [PATCH v5 5/5] tools: i3c: add i3ctransfer utility Sam Agazaryan
4 siblings, 1 reply; 7+ messages in thread
From: Sam Agazaryan @ 2026-09-21 23:06 UTC (permalink / raw)
To: linux-i3c, Alexandre Belloni, Frank Li
Cc: Greg Kroah-Hartman, Wolfram Sang, Arnd Bergmann, Adrian Hunter,
Meagan Lloyd, Vitor Soares, Oleksandr Shulzhenko,
Boris Brezillon, linux-kernel, Sam Agazaryan
Currently only the amd and svc I3C controller drivers populate
i3c_xfer.actual_len on reads, while dw-i3c-master and mipi-i3c-hci
overwrite i3c_xfer.len with the received byte count and leave actual_len
as 0. Because of this inconsistency, mctp-i3c reads xfer.len instead of
xfer.actual_len, making it fail on controllers that do not mutate len.
Unify read length reporting across the subsystem:
- Clarify in <linux/i3c/device.h> that actual_len reflects the actual
number of bytes transferred on reads.
- Update adi, cdns, dw, mipi-i3c-hci, and renesas controller drivers to
populate actual_len on read transfers without mutating len.
- Update mctp-i3c to read xfer.actual_len instead of xfer.len.
Co-developed-by: Meagan Lloyd <meaganlloyd@linux.microsoft.com>
Signed-off-by: Meagan Lloyd <meaganlloyd@linux.microsoft.com>
Signed-off-by: Sam Agazaryan <samagazaryan@google.com>
---
drivers/i3c/master/adi-i3c-master.c | 5 ++++-
drivers/i3c/master/dw-i3c-master.c | 2 +-
drivers/i3c/master/i3c-master-cdns.c | 5 ++++-
drivers/i3c/master/mipi-i3c-hci/core.c | 2 +-
drivers/i3c/master/renesas-i3c.c | 3 +++
drivers/net/mctp/mctp-i3c.c | 10 +++++-----
include/linux/i3c/device.h | 2 +-
7 files changed, 19 insertions(+), 10 deletions(-)
diff --git a/drivers/i3c/master/adi-i3c-master.c b/drivers/i3c/master/adi-i3c-master.c
index b35386260350..d033bfd4ecc2 100644
--- a/drivers/i3c/master/adi-i3c-master.c
+++ b/drivers/i3c/master/adi-i3c-master.c
@@ -412,8 +412,11 @@ static int adi_i3c_master_i3c_xfers(struct i3c_dev_desc *dev,
ret = xfer->ret;
- for (i = 0; i < nxfers; i++)
+ for (i = 0; i < nxfers; i++) {
xfers[i].err = adi_i3c_cmd_get_err(&xfer->cmds[i]);
+ if (xfers[i].rnw)
+ xfers[i].actual_len = xfer->cmds[i].rx_len;
+ }
return ret;
}
diff --git a/drivers/i3c/master/dw-i3c-master.c b/drivers/i3c/master/dw-i3c-master.c
index 4563d8761ba0..28e8eb293747 100644
--- a/drivers/i3c/master/dw-i3c-master.c
+++ b/drivers/i3c/master/dw-i3c-master.c
@@ -1029,7 +1029,7 @@ static int dw_i3c_master_i3c_xfers(struct i3c_dev_desc *dev,
struct dw_i3c_cmd *cmd = &xfer->cmds[i];
if (i3c_xfers[i].rnw)
- i3c_xfers[i].len = cmd->rx_len;
+ i3c_xfers[i].actual_len = cmd->rx_len;
}
ret = xfer->ret;
diff --git a/drivers/i3c/master/i3c-master-cdns.c b/drivers/i3c/master/i3c-master-cdns.c
index 2d98c1ce9b12..331062c10b31 100644
--- a/drivers/i3c/master/i3c-master-cdns.c
+++ b/drivers/i3c/master/i3c-master-cdns.c
@@ -795,8 +795,11 @@ static int cdns_i3c_master_i3c_xfers(struct i3c_dev_desc *dev,
ret = cdns_xfer->ret;
- for (i = 0; i < nxfers; i++)
+ for (i = 0; i < nxfers; i++) {
xfers[i].err = cdns_i3c_cmd_get_err(&cdns_xfer->cmds[i]);
+ if (xfers[i].rnw)
+ xfers[i].actual_len = cdns_xfer->cmds[i].rx_len;
+ }
cdns_i3c_master_free_xfer(cdns_xfer);
diff --git a/drivers/i3c/master/mipi-i3c-hci/core.c b/drivers/i3c/master/mipi-i3c-hci/core.c
index dadf049bd4b5..f74c02fab9e3 100644
--- a/drivers/i3c/master/mipi-i3c-hci/core.c
+++ b/drivers/i3c/master/mipi-i3c-hci/core.c
@@ -509,7 +509,7 @@ static int i3c_hci_i3c_xfers(struct i3c_dev_desc *dev,
goto out;
for (i = 0; i < nxfers; i++) {
if (i3c_xfers[i].rnw)
- i3c_xfers[i].len = RESP_DATA_LENGTH(xfer[i].response);
+ i3c_xfers[i].actual_len = RESP_DATA_LENGTH(xfer[i].response);
if (RESP_STATUS(xfer[i].response) != RESP_SUCCESS) {
ret = -EIO;
goto out;
diff --git a/drivers/i3c/master/renesas-i3c.c b/drivers/i3c/master/renesas-i3c.c
index 28c0927a0179..a3dcb4cd9b0e 100644
--- a/drivers/i3c/master/renesas-i3c.c
+++ b/drivers/i3c/master/renesas-i3c.c
@@ -918,6 +918,9 @@ static int renesas_i3c_i3c_xfers(struct i3c_dev_desc *dev, struct i3c_xfer *i3c_
time_left = renesas_i3c_wait_xfer(i3c, xfer);
if (!time_left)
xfer_failed = true;
+
+ if (i3c_xfers[i].rnw)
+ i3c_xfers[i].actual_len = cmd->rx_count;
}
if (xfer_failed)
diff --git a/drivers/net/mctp/mctp-i3c.c b/drivers/net/mctp/mctp-i3c.c
index 6d2bbae7477b..5f94c11a1712 100644
--- a/drivers/net/mctp/mctp-i3c.c
+++ b/drivers/net/mctp/mctp-i3c.c
@@ -131,12 +131,12 @@ static int mctp_i3c_read(struct mctp_i3c_device *mi)
if (rc < 0)
goto err;
- if (WARN_ON_ONCE(xfer.len > mi->mrl)) {
+ if (WARN_ON_ONCE(xfer.actual_len > mi->mrl)) {
/* Bad i3c bus driver */
rc = -EIO;
goto err;
}
- if (xfer.len < MCTP_I3C_MINLEN) {
+ if (xfer.actual_len < MCTP_I3C_MINLEN) {
stats->rx_length_errors++;
rc = -EIO;
goto err;
@@ -145,15 +145,15 @@ static int mctp_i3c_read(struct mctp_i3c_device *mi)
/* check PEC, including address byte */
addr = mi->addr << 1 | 1;
pec = i2c_smbus_pec(0, &addr, 1);
- pec = i2c_smbus_pec(pec, xfer.data.in, xfer.len - 1);
- if (pec != ((u8 *)xfer.data.in)[xfer.len - 1]) {
+ pec = i2c_smbus_pec(pec, xfer.data.in, xfer.actual_len - 1);
+ if (pec != ((u8 *)xfer.data.in)[xfer.actual_len - 1]) {
stats->rx_crc_errors++;
rc = -EINVAL;
goto err;
}
/* Remove PEC */
- skb_trim(skb, xfer.len - 1);
+ skb_trim(skb, xfer.actual_len - 1);
cb = __mctp_cb(skb);
cb->halen = PID_SIZE;
diff --git a/include/linux/i3c/device.h b/include/linux/i3c/device.h
index 971d53349b6f..f868a7bf2bc9 100644
--- a/include/linux/i3c/device.h
+++ b/include/linux/i3c/device.h
@@ -59,7 +59,7 @@ enum i3c_xfer_mode {
* @rnw: encodes the transfer direction. true for a read, false for a write
* @cmd: Read/Write command in HDR mode, read: 0x80 - 0xff, write: 0x00 - 0x7f
* @len: transfer length in bytes of the transfer
- * @actual_len: actual length in bytes are transferred by the controller
+ * @actual_len: actual length in bytes transferred by the controller on read
* @data: input/output buffer
* @data.in: input buffer. Must point to a DMA-able buffer
* @data.out: output buffer. Must point to a DMA-able buffer
--
2.55.0.1082.g2b9226bbc0-goog
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: [PATCH v5 3/5] i3c: use actual_len for read transfers
2026-09-21 23:06 ` [PATCH v5 3/5] i3c: use actual_len for read transfers Sam Agazaryan
@ 2026-09-24 11:53 ` Adrian Hunter
0 siblings, 0 replies; 7+ messages in thread
From: Adrian Hunter @ 2026-09-24 11:53 UTC (permalink / raw)
To: Sam Agazaryan, linux-i3c, Alexandre Belloni, Frank Li
Cc: Greg Kroah-Hartman, Wolfram Sang, Arnd Bergmann, Meagan Lloyd,
Vitor Soares, Oleksandr Shulzhenko, Boris Brezillon,
linux-kernel
On 22/09/2026 02:06, Sam Agazaryan wrote:
> Currently only the amd and svc I3C controller drivers populate
> i3c_xfer.actual_len on reads, while dw-i3c-master and mipi-i3c-hci
> overwrite i3c_xfer.len with the received byte count and leave actual_len
> as 0. Because of this inconsistency, mctp-i3c reads xfer.len instead of
> xfer.actual_len, making it fail on controllers that do not mutate len.
>
> Unify read length reporting across the subsystem:
> - Clarify in <linux/i3c/device.h> that actual_len reflects the actual
> number of bytes transferred on reads.
> - Update adi, cdns, dw, mipi-i3c-hci, and renesas controller drivers to
> populate actual_len on read transfers without mutating len.
> - Update mctp-i3c to read xfer.actual_len instead of xfer.len.
>
> Co-developed-by: Meagan Lloyd <meaganlloyd@linux.microsoft.com>
> Signed-off-by: Meagan Lloyd <meaganlloyd@linux.microsoft.com>
> Signed-off-by: Sam Agazaryan <samagazaryan@google.com>
Looks good.
1 issue from Sashiko:
https://sashiko.dev/#/patchset/20260921230603.2518652-1-samagazaryan%40google.com?part=3
Also i3c_dev_do_xfers_locked() should probably clamp actual_len to len.
> ---
> drivers/i3c/master/adi-i3c-master.c | 5 ++++-
> drivers/i3c/master/dw-i3c-master.c | 2 +-
> drivers/i3c/master/i3c-master-cdns.c | 5 ++++-
> drivers/i3c/master/mipi-i3c-hci/core.c | 2 +-
> drivers/i3c/master/renesas-i3c.c | 3 +++
> drivers/net/mctp/mctp-i3c.c | 10 +++++-----
> include/linux/i3c/device.h | 2 +-
> 7 files changed, 19 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/i3c/master/adi-i3c-master.c b/drivers/i3c/master/adi-i3c-master.c
> index b35386260350..d033bfd4ecc2 100644
> --- a/drivers/i3c/master/adi-i3c-master.c
> +++ b/drivers/i3c/master/adi-i3c-master.c
> @@ -412,8 +412,11 @@ static int adi_i3c_master_i3c_xfers(struct i3c_dev_desc *dev,
>
> ret = xfer->ret;
>
> - for (i = 0; i < nxfers; i++)
> + for (i = 0; i < nxfers; i++) {
> xfers[i].err = adi_i3c_cmd_get_err(&xfer->cmds[i]);
> + if (xfers[i].rnw)
> + xfers[i].actual_len = xfer->cmds[i].rx_len;
> + }
>
> return ret;
> }
> diff --git a/drivers/i3c/master/dw-i3c-master.c b/drivers/i3c/master/dw-i3c-master.c
> index 4563d8761ba0..28e8eb293747 100644
> --- a/drivers/i3c/master/dw-i3c-master.c
> +++ b/drivers/i3c/master/dw-i3c-master.c
> @@ -1029,7 +1029,7 @@ static int dw_i3c_master_i3c_xfers(struct i3c_dev_desc *dev,
> struct dw_i3c_cmd *cmd = &xfer->cmds[i];
>
> if (i3c_xfers[i].rnw)
> - i3c_xfers[i].len = cmd->rx_len;
> + i3c_xfers[i].actual_len = cmd->rx_len;
> }
>
> ret = xfer->ret;
> diff --git a/drivers/i3c/master/i3c-master-cdns.c b/drivers/i3c/master/i3c-master-cdns.c
> index 2d98c1ce9b12..331062c10b31 100644
> --- a/drivers/i3c/master/i3c-master-cdns.c
> +++ b/drivers/i3c/master/i3c-master-cdns.c
> @@ -795,8 +795,11 @@ static int cdns_i3c_master_i3c_xfers(struct i3c_dev_desc *dev,
>
> ret = cdns_xfer->ret;
>
> - for (i = 0; i < nxfers; i++)
> + for (i = 0; i < nxfers; i++) {
> xfers[i].err = cdns_i3c_cmd_get_err(&cdns_xfer->cmds[i]);
> + if (xfers[i].rnw)
> + xfers[i].actual_len = cdns_xfer->cmds[i].rx_len;
> + }
>
> cdns_i3c_master_free_xfer(cdns_xfer);
>
> diff --git a/drivers/i3c/master/mipi-i3c-hci/core.c b/drivers/i3c/master/mipi-i3c-hci/core.c
> index dadf049bd4b5..f74c02fab9e3 100644
> --- a/drivers/i3c/master/mipi-i3c-hci/core.c
> +++ b/drivers/i3c/master/mipi-i3c-hci/core.c
> @@ -509,7 +509,7 @@ static int i3c_hci_i3c_xfers(struct i3c_dev_desc *dev,
> goto out;
> for (i = 0; i < nxfers; i++) {
> if (i3c_xfers[i].rnw)
> - i3c_xfers[i].len = RESP_DATA_LENGTH(xfer[i].response);
> + i3c_xfers[i].actual_len = RESP_DATA_LENGTH(xfer[i].response);
> if (RESP_STATUS(xfer[i].response) != RESP_SUCCESS) {
> ret = -EIO;
> goto out;
> diff --git a/drivers/i3c/master/renesas-i3c.c b/drivers/i3c/master/renesas-i3c.c
> index 28c0927a0179..a3dcb4cd9b0e 100644
> --- a/drivers/i3c/master/renesas-i3c.c
> +++ b/drivers/i3c/master/renesas-i3c.c
> @@ -918,6 +918,9 @@ static int renesas_i3c_i3c_xfers(struct i3c_dev_desc *dev, struct i3c_xfer *i3c_
> time_left = renesas_i3c_wait_xfer(i3c, xfer);
> if (!time_left)
> xfer_failed = true;
> +
> + if (i3c_xfers[i].rnw)
> + i3c_xfers[i].actual_len = cmd->rx_count;
> }
>
> if (xfer_failed)
> diff --git a/drivers/net/mctp/mctp-i3c.c b/drivers/net/mctp/mctp-i3c.c
> index 6d2bbae7477b..5f94c11a1712 100644
> --- a/drivers/net/mctp/mctp-i3c.c
> +++ b/drivers/net/mctp/mctp-i3c.c
> @@ -131,12 +131,12 @@ static int mctp_i3c_read(struct mctp_i3c_device *mi)
> if (rc < 0)
> goto err;
>
> - if (WARN_ON_ONCE(xfer.len > mi->mrl)) {
> + if (WARN_ON_ONCE(xfer.actual_len > mi->mrl)) {
> /* Bad i3c bus driver */
> rc = -EIO;
> goto err;
> }
> - if (xfer.len < MCTP_I3C_MINLEN) {
> + if (xfer.actual_len < MCTP_I3C_MINLEN) {
> stats->rx_length_errors++;
> rc = -EIO;
> goto err;
> @@ -145,15 +145,15 @@ static int mctp_i3c_read(struct mctp_i3c_device *mi)
> /* check PEC, including address byte */
> addr = mi->addr << 1 | 1;
> pec = i2c_smbus_pec(0, &addr, 1);
> - pec = i2c_smbus_pec(pec, xfer.data.in, xfer.len - 1);
> - if (pec != ((u8 *)xfer.data.in)[xfer.len - 1]) {
> + pec = i2c_smbus_pec(pec, xfer.data.in, xfer.actual_len - 1);
> + if (pec != ((u8 *)xfer.data.in)[xfer.actual_len - 1]) {
> stats->rx_crc_errors++;
> rc = -EINVAL;
> goto err;
> }
>
> /* Remove PEC */
> - skb_trim(skb, xfer.len - 1);
> + skb_trim(skb, xfer.actual_len - 1);
>
> cb = __mctp_cb(skb);
> cb->halen = PID_SIZE;
> diff --git a/include/linux/i3c/device.h b/include/linux/i3c/device.h
> index 971d53349b6f..f868a7bf2bc9 100644
> --- a/include/linux/i3c/device.h
> +++ b/include/linux/i3c/device.h
> @@ -59,7 +59,7 @@ enum i3c_xfer_mode {
> * @rnw: encodes the transfer direction. true for a read, false for a write
> * @cmd: Read/Write command in HDR mode, read: 0x80 - 0xff, write: 0x00 - 0x7f
> * @len: transfer length in bytes of the transfer
> - * @actual_len: actual length in bytes are transferred by the controller
> + * @actual_len: actual length in bytes transferred by the controller on read
> * @data: input/output buffer
> * @data.in: input buffer. Must point to a DMA-able buffer
> * @data.out: output buffer. Must point to a DMA-able buffer
^ permalink raw reply [flat|nested] 7+ messages in thread
* [PATCH v5 4/5] i3c: add i3cdev module to expose i3c dev in /dev
2026-09-21 23:05 [PATCH v5 0/5] i3c: add i3cdev module to expose i3c dev in /dev Sam Agazaryan
` (2 preceding siblings ...)
2026-09-21 23:06 ` [PATCH v5 3/5] i3c: use actual_len for read transfers Sam Agazaryan
@ 2026-09-21 23:06 ` Sam Agazaryan
2026-09-21 23:06 ` [PATCH v5 5/5] tools: i3c: add i3ctransfer utility Sam Agazaryan
4 siblings, 0 replies; 7+ messages in thread
From: Sam Agazaryan @ 2026-09-21 23:06 UTC (permalink / raw)
To: linux-i3c, Alexandre Belloni, Frank Li
Cc: Greg Kroah-Hartman, Wolfram Sang, Arnd Bergmann, Adrian Hunter,
Meagan Lloyd, Vitor Soares, Oleksandr Shulzhenko,
Boris Brezillon, linux-kernel, Sam Agazaryan
From: Vitor Soares <vitor.soares@toradex.com>
Add userspace character device support for I3C transfers via /dev.
The module allows userspace programs to interact directly with I3C
targets that do not have a kernel driver bound to them, such as devices
in ROM/bootloader recovery mode (e.g. OCP Secure Firmware Recovery v1.1
and Caliptra Silicon Root of Trust recovery flows).
Features:
- Dynamically exposes /dev/bus/i3c/<device> character devices for I3C
devices when unbound from kernel drivers.
- Dynamically allocates character device minor numbers using the IDA
allocator.
- Implements SDR and HDR transfers via I3C_IOC_XFER ioctl with 64-bit
aligned UAPI data structures and actual_len read reporting.
- Supports compat_ptr_ioctl for 32-bit userspace on 64-bit kernels.
- Uses cdev_device_add/cdev_device_del with device refcounting to ensure
safe lifecycle management and prevent use-after-free on driver detach.
Signed-off-by: Vitor Soares <vitor.soares@toradex.com>
Co-developed-by: Oleksandr Shulzhenko <oleksandr.shulzhenko.viktorovych@intel.com>
Signed-off-by: Oleksandr Shulzhenko <oleksandr.shulzhenko.viktorovych@intel.com>
Co-developed-by: Sam Agazaryan <samagazaryan@google.com>
Signed-off-by: Sam Agazaryan <samagazaryan@google.com>
---
MAINTAINERS | 1 +
drivers/i3c/Kconfig | 11 +
drivers/i3c/Makefile | 1 +
drivers/i3c/i3cdev.c | 491 ++++++++++++++++++++++++++++++++
include/uapi/linux/i3c/i3cdev.h | 57 ++++
5 files changed, 561 insertions(+)
create mode 100644 drivers/i3c/i3cdev.c
create mode 100644 include/uapi/linux/i3c/i3cdev.h
diff --git a/MAINTAINERS b/MAINTAINERS
index 81a9a02c919d..30a5cb12c4f0 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -12364,6 +12364,7 @@ F: Documentation/driver-api/i3c
F: drivers/i3c/
F: include/dt-bindings/i3c/
F: include/linux/i3c/
+F: include/uapi/linux/i3c/
IBM Operation Panel Input Driver
M: Eddie James <eajames@linux.ibm.com>
diff --git a/drivers/i3c/Kconfig b/drivers/i3c/Kconfig
index 626c54b386d5..166875837ec6 100644
--- a/drivers/i3c/Kconfig
+++ b/drivers/i3c/Kconfig
@@ -20,6 +20,17 @@ menuconfig I3C
will be called i3c.
if I3C
+
+config I3CDEV
+ tristate "I3C device interface"
+ help
+ Say Y here to use i3c-* device files, usually found in the /dev
+ directory on your system. They make it possible to have user-space
+ programs use the I3C devices.
+
+ This support is also available as a module. If so, the module
+ will be called i3cdev.
+
source "drivers/i3c/master/Kconfig"
endif # I3C
diff --git a/drivers/i3c/Makefile b/drivers/i3c/Makefile
index 11982efbc6d9..606d422841b2 100644
--- a/drivers/i3c/Makefile
+++ b/drivers/i3c/Makefile
@@ -1,4 +1,5 @@
# SPDX-License-Identifier: GPL-2.0
i3c-y := device.o master.o
obj-$(CONFIG_I3C) += i3c.o
+obj-$(CONFIG_I3CDEV) += i3cdev.o
obj-$(CONFIG_I3C) += master/
diff --git a/drivers/i3c/i3cdev.c b/drivers/i3c/i3cdev.c
new file mode 100644
index 000000000000..309ce8181209
--- /dev/null
+++ b/drivers/i3c/i3cdev.c
@@ -0,0 +1,491 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2020 Synopsys, Inc. and/or its affiliates.
+ * Copyright (c) 2026 Google LLC
+ *
+ * Author: Vitor Soares <soares@synopsys.com>
+ * Author: Sam Agazaryan <samagazaryan@google.com>
+ */
+
+#include <linux/cdev.h>
+#include <linux/cleanup.h>
+#include <linux/compat.h>
+#include <linux/device.h>
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/jiffies.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/notifier.h>
+#include <linux/overflow.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+
+#include <linux/i3c/i3cdev.h>
+
+#include "internals.h"
+
+struct i3cdev_data {
+ struct list_head list;
+ struct i3c_device *i3c;
+ struct device dev;
+ struct mutex xfer_lock; /* prevent detach while transferring */
+ struct cdev cdev;
+ int id;
+};
+
+static DEFINE_IDA(i3cdev_ida);
+static LIST_HEAD(i3cdev_list);
+static DEFINE_MUTEX(i3cdev_attach_lock);
+static dev_t i3cdev_number;
+#define I3C_MINORS (MINORMASK + 1)
+
+static void i3cdev_dev_release(struct device *dev)
+{
+ struct i3cdev_data *i3cdev = container_of(dev, struct i3cdev_data, dev);
+
+ ida_free(&i3cdev_ida, i3cdev->id);
+ kfree(i3cdev);
+}
+
+static struct i3cdev_data *i3cdev_get_by_i3c(struct i3c_device *i3c)
+{
+ struct i3cdev_data *i3cdev;
+
+ list_for_each_entry(i3cdev, &i3cdev_list, list) {
+ if (i3cdev->i3c == i3c)
+ return i3cdev;
+ }
+
+ return NULL;
+}
+
+static struct i3cdev_data *get_free_i3cdev(struct i3c_device *i3c)
+{
+ struct i3cdev_data *i3cdev;
+ int id;
+
+ id = ida_alloc_max(&i3cdev_ida, MINORMASK, GFP_KERNEL);
+ if (id < 0) {
+ pr_err("i3cdev: no minor number available!\n");
+ return ERR_PTR(id);
+ }
+
+ i3cdev = kzalloc_obj(*i3cdev, GFP_KERNEL);
+ if (!i3cdev) {
+ ida_free(&i3cdev_ida, id);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ i3cdev->i3c = i3c;
+ i3cdev->id = id;
+ list_add_tail(&i3cdev->list, &i3cdev_list);
+
+ return i3cdev;
+}
+
+static ssize_t
+i3cdev_read(struct file *file, char __user *buf, size_t count, loff_t *f_pos)
+{
+ char *tmp __free(kfree) = NULL;
+ struct i3cdev_data *i3cdev = file->private_data;
+ struct i3c_xfer xfers = {
+ .rnw = true,
+ };
+ struct i3c_device *i3c;
+ int ret;
+
+ count = min_t(size_t, count, type_max(xfers.len));
+ xfers.len = count;
+
+ tmp = kzalloc(count, GFP_KERNEL);
+ if (!tmp)
+ return -ENOMEM;
+
+ guard(mutex)(&i3cdev->xfer_lock);
+ i3c = i3cdev->i3c;
+ if (!i3c || i3c->dev.driver)
+ return -ENODEV;
+
+ xfers.data.in = tmp;
+
+ dev_dbg(&i3c->dev, "Reading %zu bytes.\n", count);
+
+ ret = i3c_device_do_xfers(i3c, &xfers, 1, I3C_SDR);
+ if (ret)
+ return ret;
+
+ if (copy_to_user(buf, tmp, xfers.actual_len))
+ return -EFAULT;
+
+ return xfers.actual_len;
+}
+
+static ssize_t
+i3cdev_write(struct file *file, const char __user *buf, size_t count,
+ loff_t *f_pos)
+{
+ void *tmp __free(kfree) = NULL;
+ struct i3cdev_data *i3cdev = file->private_data;
+ struct i3c_xfer xfers = {
+ .rnw = false,
+ };
+ struct i3c_device *i3c;
+ int ret;
+
+ count = min_t(size_t, count, type_max(xfers.len));
+ xfers.len = count;
+
+ tmp = memdup_user(buf, count);
+ if (IS_ERR(tmp))
+ return PTR_ERR(tmp);
+
+ guard(mutex)(&i3cdev->xfer_lock);
+ i3c = i3cdev->i3c;
+ if (!i3c || i3c->dev.driver)
+ return -ENODEV;
+
+ xfers.data.out = tmp;
+
+ dev_dbg(&i3c->dev, "Writing %zu bytes.\n", count);
+
+ ret = i3c_device_do_xfers(i3c, &xfers, 1, I3C_SDR);
+ if (ret)
+ return ret;
+
+ return count;
+}
+
+static int
+i3cdev_do_xfer(struct i3c_device *dev, struct i3c_ioc_xfer *xfers,
+ struct i3c_ioc_xfer __user *u_xfers, unsigned int nxfers)
+{
+ struct i3c_xfer *k_xfers __free(kfree) = NULL;
+ enum i3c_xfer_mode mode = xfers[0].mode;
+ u8 **data_ptrs;
+ int i, j, nalloc, ret = 0;
+
+ /* Since we have nxfers we may allocate k_xfer + *data_ptrs together */
+ k_xfers = kcalloc(nxfers, sizeof(*k_xfers) + sizeof(*data_ptrs),
+ GFP_KERNEL);
+ if (!k_xfers)
+ return -ENOMEM;
+
+ /* set data_ptrs to be after nxfers * i3c_xfer */
+ data_ptrs = (void *)k_xfers + (nxfers * sizeof(*k_xfers));
+
+ for (i = 0; i < nxfers; i++) {
+ bool is_read;
+
+ if (xfers[i].mode != mode) {
+ ret = -EINVAL;
+ break;
+ }
+
+ if (memchr_inv(xfers[i].pad, 0, sizeof(xfers[i].pad))) {
+ ret = -EINVAL;
+ break;
+ }
+
+ if (mode == I3C_SDR) {
+ if (xfers[i].rnw != I3C_DEV_DIR_WRITE &&
+ xfers[i].rnw != I3C_DEV_DIR_READ) {
+ ret = -EINVAL;
+ break;
+ }
+ is_read = xfers[i].rnw == I3C_DEV_DIR_READ;
+ } else {
+ is_read = xfers[i].cmd & 0x80;
+ }
+
+ if (is_read) {
+ data_ptrs[i] = kzalloc(xfers[i].len, GFP_KERNEL);
+ if (!data_ptrs[i]) {
+ ret = -ENOMEM;
+ break;
+ }
+ k_xfers[i].data.in = data_ptrs[i];
+ } else {
+ data_ptrs[i] = memdup_user(u64_to_user_ptr(xfers[i].data),
+ xfers[i].len);
+ if (IS_ERR(data_ptrs[i])) {
+ ret = PTR_ERR(data_ptrs[i]);
+ break;
+ }
+ k_xfers[i].data.out = data_ptrs[i];
+ }
+
+ k_xfers[i].cmd = xfers[i].cmd;
+ k_xfers[i].len = xfers[i].len;
+ }
+ nalloc = i;
+
+ if (ret < 0)
+ goto err_free_mem;
+
+ ret = i3c_device_do_xfers(dev, k_xfers, nxfers, mode);
+ if (ret)
+ goto err_free_mem;
+
+ for (i = 0; i < nxfers; i++) {
+ bool is_read = (mode == I3C_SDR) ?
+ (xfers[i].rnw == I3C_DEV_DIR_READ) :
+ (xfers[i].cmd & 0x80);
+
+ if (is_read) {
+ if (copy_to_user(u64_to_user_ptr(xfers[i].data),
+ data_ptrs[i], k_xfers[i].actual_len) ||
+ put_user(k_xfers[i].actual_len,
+ &u_xfers[i].actual_len)) {
+ ret = -EFAULT;
+ break;
+ }
+ }
+ }
+
+err_free_mem:
+ for (j = 0; j < nalloc; j++)
+ kfree(data_ptrs[j]);
+ return ret;
+}
+
+static struct i3c_ioc_xfer *
+i3cdev_get_ioc_xfer(unsigned int cmd, struct i3c_ioc_xfer __user *u_xfers,
+ unsigned int *nxfers)
+{
+ u32 tmp = _IOC_SIZE(cmd);
+
+ if ((tmp % sizeof(struct i3c_ioc_xfer)) != 0)
+ return ERR_PTR(-EINVAL);
+
+ *nxfers = tmp / sizeof(struct i3c_ioc_xfer);
+ if (*nxfers == 0)
+ return ERR_PTR(-EINVAL);
+
+ return memdup_user(u_xfers, tmp);
+}
+
+static int
+i3cdev_ioc_xfer(struct i3c_device *i3c, unsigned int cmd,
+ struct i3c_ioc_xfer __user *u_xfers)
+{
+ struct i3c_ioc_xfer *k_xfers __free(kfree) = NULL;
+ unsigned int nxfers;
+
+ k_xfers = i3cdev_get_ioc_xfer(cmd, u_xfers, &nxfers);
+ if (IS_ERR(k_xfers))
+ return PTR_ERR(k_xfers);
+
+ return i3cdev_do_xfer(i3c, k_xfers, u_xfers, nxfers);
+}
+
+static long
+i3cdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+ struct i3cdev_data *i3cdev = file->private_data;
+ struct i3c_device *i3c;
+
+ if (_IOC_TYPE(cmd) != I3C_DEV_IOC_MAGIC)
+ return -ENOTTY;
+
+ /* Use the xfer_lock to prevent device detach during ioctl call */
+ guard(mutex)(&i3cdev->xfer_lock);
+ i3c = i3cdev->i3c;
+ if (!i3c || i3c->dev.driver)
+ return -ENODEV;
+
+ dev_dbg(&i3c->dev, "ioctl, cmd=0x%02x, arg=0x%02lx\n", cmd, arg);
+
+ /* Check command number and direction */
+ if (_IOC_NR(cmd) == _IOC_NR(I3C_IOC_XFER(0)) &&
+ _IOC_DIR(cmd) == (_IOC_READ | _IOC_WRITE))
+ return i3cdev_ioc_xfer(i3c, cmd,
+ (struct i3c_ioc_xfer __user *)arg);
+
+ return -ENOTTY;
+}
+
+static int i3cdev_open(struct inode *inode, struct file *file)
+{
+ struct i3cdev_data *i3cdev = container_of(inode->i_cdev,
+ struct i3cdev_data,
+ cdev);
+ file->private_data = i3cdev;
+
+ return 0;
+}
+
+static int i3cdev_release(struct inode *inode, struct file *file)
+{
+ file->private_data = NULL;
+
+ return 0;
+}
+
+static const struct file_operations i3cdev_fops = {
+ .owner = THIS_MODULE,
+ .read = i3cdev_read,
+ .write = i3cdev_write,
+ .unlocked_ioctl = i3cdev_ioctl,
+ .compat_ioctl = compat_ptr_ioctl,
+ .open = i3cdev_open,
+ .release = i3cdev_release,
+};
+
+/* ------------------------------------------------------------------------- */
+
+static const struct class i3cdev_class = {
+ .name = "i3cdev",
+};
+
+static int i3cdev_attach(struct device *dev, void *dummy)
+{
+ struct i3cdev_data *i3cdev;
+ struct i3c_device *i3c;
+ int res;
+
+ if (dev->type == &i3c_masterdev_type)
+ return 0;
+
+ i3c = dev_to_i3cdev(dev);
+
+ guard(mutex)(&i3cdev_attach_lock);
+ if (dev->driver || i3cdev_get_by_i3c(i3c))
+ return 0;
+
+ /* Get a device */
+ i3cdev = get_free_i3cdev(i3c);
+ if (IS_ERR(i3cdev))
+ return PTR_ERR(i3cdev);
+
+ mutex_init(&i3cdev->xfer_lock);
+ cdev_init(&i3cdev->cdev, &i3cdev_fops);
+ i3cdev->cdev.owner = THIS_MODULE;
+
+ device_initialize(&i3cdev->dev);
+ i3cdev->dev.devt = MKDEV(MAJOR(i3cdev_number), i3cdev->id);
+ i3cdev->dev.class = &i3cdev_class;
+ i3cdev->dev.parent = &i3c->dev;
+ i3cdev->dev.release = i3cdev_dev_release;
+
+ res = dev_set_name(&i3cdev->dev, "bus!i3c!%s", dev_name(&i3c->dev));
+ if (res)
+ goto error_put_dev;
+
+ res = cdev_device_add(&i3cdev->cdev, &i3cdev->dev);
+ if (res)
+ goto error_put_dev;
+
+ pr_debug("i3cdev: I3C device [%s] registered as minor %d\n",
+ dev_name(&i3c->dev), i3cdev->id);
+ return 0;
+
+error_put_dev:
+ list_del(&i3cdev->list);
+ put_device(&i3cdev->dev);
+ return res;
+}
+
+static int i3cdev_detach(struct device *dev, void *dummy)
+{
+ struct i3cdev_data *i3cdev;
+ struct i3c_device *i3c;
+
+ if (dev->type == &i3c_masterdev_type)
+ return 0;
+
+ i3c = dev_to_i3cdev(dev);
+
+ guard(mutex)(&i3cdev_attach_lock);
+ i3cdev = i3cdev_get_by_i3c(i3c);
+ if (!i3cdev)
+ return 0;
+
+ list_del(&i3cdev->list);
+
+ /* Prevent transfers while cdev removal */
+ scoped_guard(mutex, &i3cdev->xfer_lock)
+ i3cdev->i3c = NULL;
+
+ cdev_device_del(&i3cdev->cdev, &i3cdev->dev);
+ put_device(&i3cdev->dev);
+
+ pr_debug("i3cdev: device [%s] unregistered\n", dev_name(&i3c->dev));
+
+ return 0;
+}
+
+static int i3cdev_notifier_call(struct notifier_block *nb,
+ unsigned long action,
+ void *data)
+{
+ struct device *dev = data;
+
+ switch (action) {
+ case BUS_NOTIFY_ADD_DEVICE:
+ case BUS_NOTIFY_UNBOUND_DRIVER:
+ case BUS_NOTIFY_DRIVER_NOT_BOUND:
+ i3cdev_attach(dev, NULL);
+ break;
+ case BUS_NOTIFY_DEL_DEVICE:
+ case BUS_NOTIFY_REMOVED_DEVICE:
+ case BUS_NOTIFY_BIND_DRIVER:
+ i3cdev_detach(dev, NULL);
+ break;
+ }
+
+ return NOTIFY_OK;
+}
+
+static struct notifier_block i3cdev_notifier = {
+ .notifier_call = i3cdev_notifier_call,
+};
+
+static int __init i3cdev_init(void)
+{
+ int res;
+
+ /* Dynamically request unused major number */
+ res = alloc_chrdev_region(&i3cdev_number, 0, I3C_MINORS, "i3c");
+ if (res)
+ goto out;
+
+ /* Register device class to populate sysfs entries */
+ res = class_register(&i3cdev_class);
+ if (res)
+ goto out_unreg_chrdev;
+
+ /* Keep track of busses which have devices to add or remove later */
+ res = bus_register_notifier(&i3c_bus_type, &i3cdev_notifier);
+ if (res)
+ goto out_unreg_class;
+
+ /* Bind to already existing device without driver right away */
+ i3c_for_each_dev(NULL, i3cdev_attach);
+
+ return 0;
+
+out_unreg_class:
+ class_unregister(&i3cdev_class);
+out_unreg_chrdev:
+ unregister_chrdev_region(i3cdev_number, I3C_MINORS);
+out:
+ pr_err("%s: Driver Initialisation failed\n", __FILE__);
+ return res;
+}
+
+static void __exit i3cdev_exit(void)
+{
+ bus_unregister_notifier(&i3c_bus_type, &i3cdev_notifier);
+ i3c_for_each_dev(NULL, i3cdev_detach);
+ class_unregister(&i3cdev_class);
+ unregister_chrdev_region(i3cdev_number, I3C_MINORS);
+}
+
+MODULE_AUTHOR("Vitor Soares <soares@synopsys.com>");
+MODULE_DESCRIPTION("I3C /dev entries driver");
+MODULE_LICENSE("GPL");
+
+module_init(i3cdev_init);
+module_exit(i3cdev_exit);
diff --git a/include/uapi/linux/i3c/i3cdev.h b/include/uapi/linux/i3c/i3cdev.h
new file mode 100644
index 000000000000..69e901017378
--- /dev/null
+++ b/include/uapi/linux/i3c/i3cdev.h
@@ -0,0 +1,57 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/*
+ * Copyright (c) 2020 Synopsys, Inc. and/or its affiliates.
+ * Copyright (c) 2026 Google LLC
+ *
+ * Author: Vitor Soares <vitor.soares@synopsys.com>
+ */
+
+#ifndef _UAPI_I3C_DEV_H_
+#define _UAPI_I3C_DEV_H_
+
+#include <linux/types.h>
+#include <linux/ioctl.h>
+
+/* IOCTL commands */
+#define I3C_DEV_IOC_MAGIC 0x07
+
+#define I3C_DEV_DIR_WRITE 0
+#define I3C_DEV_DIR_READ 1
+
+#define I3C_XFER_MODE_HDR_DDR 0
+#define I3C_XFER_MODE_HDR_TSP 1
+#define I3C_XFER_MODE_HDR_TSL 2
+#define I3C_XFER_MODE_SDR 31
+
+/**
+ * struct i3c_ioc_xfer - I3C ioctl transfer
+ * @data: Holds pointer to userspace buffer with transmit/receive data.
+ * @len: Length of data buffer, in bytes.
+ * @actual_len: Actual length of data transferred on read, in bytes (output).
+ * @rnw: Transfer direction for SDR mode (I3C_DEV_DIR_WRITE or I3C_DEV_DIR_READ).
+ * @cmd: Command byte for HDR mode (0x00-0x7f write, 0x80-0xff read).
+ * @mode: Transfer mode (I3C_XFER_MODE_SDR, I3C_XFER_MODE_HDR_DDR, etc.).
+ * @pad: Reserved for future extensions; must be zeroed.
+ */
+struct i3c_ioc_xfer {
+ __u64 data;
+ __u16 len;
+ __u16 actual_len;
+ union {
+ __u8 rnw;
+ __u8 cmd;
+ };
+ __u8 mode;
+ __u8 pad[2];
+};
+
+#define __I3C_XFER_SIZE(type) \
+ ((((sizeof(struct i3c_ioc_xfer)) * (type)) < (1 << _IOC_SIZEBITS)) \
+ ? ((sizeof(struct i3c_ioc_xfer)) * (type)) : 0)
+
+#define I3C_XFER_SIZE(N) __I3C_XFER_SIZE(N)
+
+#define I3C_IOC_XFER(N) \
+ _IOC(_IOC_READ | _IOC_WRITE, I3C_DEV_IOC_MAGIC, 30, I3C_XFER_SIZE(N))
+
+#endif
--
2.55.0.1082.g2b9226bbc0-goog
^ permalink raw reply [flat|nested] 7+ messages in thread* [PATCH v5 5/5] tools: i3c: add i3ctransfer utility
2026-09-21 23:05 [PATCH v5 0/5] i3c: add i3cdev module to expose i3c dev in /dev Sam Agazaryan
` (3 preceding siblings ...)
2026-09-21 23:06 ` [PATCH v5 4/5] i3c: add i3cdev module to expose i3c dev in /dev Sam Agazaryan
@ 2026-09-21 23:06 ` Sam Agazaryan
4 siblings, 0 replies; 7+ messages in thread
From: Sam Agazaryan @ 2026-09-21 23:06 UTC (permalink / raw)
To: linux-i3c, Alexandre Belloni, Frank Li
Cc: Greg Kroah-Hartman, Wolfram Sang, Arnd Bergmann, Adrian Hunter,
Meagan Lloyd, Vitor Soares, Oleksandr Shulzhenko,
Boris Brezillon, linux-kernel, Sam Agazaryan
Add the i3ctransfer userspace utility to tools/i3c/ for testing and
interacting with I3C target devices via /dev/bus/i3c/* character
devices.
Based on the i3ctransfer tool from i3c-tools by Vitor Soares, updated
for the unified I3C_IOC_XFER UAPI (struct i3c_ioc_xfer):
- Supports SDR and HDR (HDR-DDR, HDR-TSP, HDR-TSL) transfer modes
via -m/--mode and -c/--command options.
- Reports actual_len bytes received on read transfers.
Signed-off-by: Sam Agazaryan <samagazaryan@google.com>
---
Note to Vitor Soares:
This patch ports your GPL-2.0 i3ctransfer utility from i3c-tools into
tools/i3c/ and updates it for struct i3c_ioc_xfer (SDR/HDR modes and
actual_len read reporting). Since the original GitHub commit did not
include a Signed-off-by tag, could you please reply with your
Signed-off-by or Acked-by so we can properly record your sign-off?
MAINTAINERS | 1 +
tools/Makefile | 13 +-
tools/i3c/Build | 1 +
tools/i3c/Makefile | 58 ++++++++
tools/i3c/i3ctransfer.c | 307 ++++++++++++++++++++++++++++++++++++++++
5 files changed, 374 insertions(+), 6 deletions(-)
create mode 100644 tools/i3c/Build
create mode 100644 tools/i3c/Makefile
create mode 100644 tools/i3c/i3ctransfer.c
diff --git a/MAINTAINERS b/MAINTAINERS
index 30a5cb12c4f0..8a4166ebc9dc 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -12365,6 +12365,7 @@ F: drivers/i3c/
F: include/dt-bindings/i3c/
F: include/linux/i3c/
F: include/uapi/linux/i3c/
+F: tools/i3c/
IBM Operation Panel Input Driver
M: Eddie James <eajames@linux.ibm.com>
diff --git a/tools/Makefile b/tools/Makefile
index cb40961a740f..7c17e7555fd7 100644
--- a/tools/Makefile
+++ b/tools/Makefile
@@ -20,6 +20,7 @@ help:
@echo ' freefall - laptop accelerometer program for disk protection'
@echo ' gpio - GPIO tools'
@echo ' hv - tools used when in Hyper-V clients'
+ @echo ' i3c - I3C tools'
@echo ' iio - IIO tools'
@echo ' intel-speed-select - Intel Speed Select tool'
@echo ' kvm_stat - top-like utility for displaying kvm statistics'
@@ -70,7 +71,7 @@ acpi: FORCE
cpupower: FORCE
$(call descend,power/$@)
-counter dma firewire hv guest bootconfig spi usb virtio mm bpf iio gpio objtool leds wmi firmware debugging tracing: FORCE
+counter dma firewire hv guest bootconfig spi usb virtio mm bpf i3c iio gpio objtool leds wmi firmware debugging tracing: FORCE
$(call descend,$@)
bpf/%: FORCE
@@ -126,7 +127,7 @@ ynl: FORCE
all: acpi counter cpupower dma gpio hv firewire \
perf selftests bootconfig spi turbostat usb \
virtio mm bpf x86_energy_perf_policy \
- tmon freefall iio objtool kvm_stat wmi \
+ tmon freefall i3c iio objtool kvm_stat wmi \
debugging tracing thermal thermometer thermal-engine ynl
acpi_install:
@@ -135,7 +136,7 @@ acpi_install:
cpupower_install:
$(call descend,power/$(@:_install=),install)
-counter_install dma_install firewire_install gpio_install hv_install iio_install perf_install bootconfig_install spi_install usb_install virtio_install mm_install bpf_install objtool_install wmi_install debugging_install tracing_install:
+counter_install dma_install firewire_install gpio_install hv_install i3c_install iio_install perf_install bootconfig_install spi_install usb_install virtio_install mm_install bpf_install objtool_install wmi_install debugging_install tracing_install:
$(call descend,$(@:_install=),install)
selftests_install:
@@ -166,7 +167,7 @@ ynl_install:
$(call descend,net/$(@:_install=),install)
install: acpi_install counter_install cpupower_install dma_install gpio_install \
- hv_install firewire_install iio_install \
+ hv_install firewire_install i3c_install iio_install \
perf_install selftests_install turbostat_install usb_install \
virtio_install mm_install bpf_install x86_energy_perf_policy_install \
tmon_install freefall_install objtool_install kvm_stat_install \
@@ -179,7 +180,7 @@ acpi_clean:
cpupower_clean:
$(call descend,power/cpupower,clean)
-counter_clean dma_clean hv_clean firewire_clean bootconfig_clean spi_clean usb_clean virtio_clean mm_clean wmi_clean bpf_clean iio_clean gpio_clean objtool_clean leds_clean firmware_clean debugging_clean tracing_clean:
+counter_clean dma_clean hv_clean firewire_clean bootconfig_clean spi_clean usb_clean virtio_clean mm_clean wmi_clean bpf_clean i3c_clean iio_clean gpio_clean objtool_clean leds_clean firmware_clean debugging_clean tracing_clean:
$(call descend,$(@:_clean=),clean)
libapi_clean:
@@ -227,7 +228,7 @@ ynl_clean:
clean: acpi_clean counter_clean cpupower_clean dma_clean hv_clean firewire_clean \
perf_clean selftests_clean turbostat_clean bootconfig_clean spi_clean usb_clean virtio_clean \
- mm_clean bpf_clean iio_clean x86_energy_perf_policy_clean tmon_clean \
+ mm_clean bpf_clean i3c_clean iio_clean x86_energy_perf_policy_clean tmon_clean \
freefall_clean build_clean libbpf_clean libsubcmd_clean \
gpio_clean objtool_clean leds_clean wmi_clean firmware_clean debugging_clean \
intel-speed-select_clean tracing_clean thermal_clean thermometer_clean thermal-engine_clean \
diff --git a/tools/i3c/Build b/tools/i3c/Build
new file mode 100644
index 000000000000..6a22328ad983
--- /dev/null
+++ b/tools/i3c/Build
@@ -0,0 +1 @@
+i3ctransfer-y += i3ctransfer.o
diff --git a/tools/i3c/Makefile b/tools/i3c/Makefile
new file mode 100644
index 000000000000..43ce8769185b
--- /dev/null
+++ b/tools/i3c/Makefile
@@ -0,0 +1,58 @@
+# SPDX-License-Identifier: GPL-2.0-only
+include ../scripts/Makefile.include
+
+bindir ?= /usr/bin
+
+ifeq ($(srctree),)
+srctree := $(patsubst %/,%,$(dir $(CURDIR)))
+srctree := $(patsubst %/,%,$(dir $(srctree)))
+endif
+
+# Do not use make's built-in rules
+# (this improves performance and avoids hard-to-debug behaviour);
+MAKEFLAGS += -r
+
+CFLAGS += -O2 -Wall -g -D_GNU_SOURCE -I$(OUTPUT)include
+
+ALL_TARGETS := i3ctransfer
+ALL_PROGRAMS := $(patsubst %,$(OUTPUT)%,$(ALL_TARGETS))
+
+all: $(ALL_PROGRAMS)
+
+export srctree OUTPUT CC LD CFLAGS
+include $(srctree)/tools/build/Makefile.include
+
+#
+# We need the following to be outside of kernel tree
+#
+$(OUTPUT)include/linux/i3c: ../../include/uapi/linux/i3c
+ mkdir -p $(OUTPUT)include/linux/i3c 2>&1 || true
+ ln -sf $(CURDIR)/../../include/uapi/linux/i3c/i3cdev.h $@
+
+prepare: $(OUTPUT)include/linux/i3c
+
+#
+# i3ctransfer
+#
+I3CTRANSFER_IN := $(OUTPUT)i3ctransfer-in.o
+$(I3CTRANSFER_IN): prepare FORCE
+ $(Q)$(MAKE) $(build)=i3ctransfer
+$(OUTPUT)i3ctransfer: $(I3CTRANSFER_IN)
+ $(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) $< -o $@
+
+clean:
+ rm -f $(ALL_PROGRAMS)
+ rm -rf $(OUTPUT)include/
+ find $(or $(OUTPUT),.) -name '*.o' -delete
+ find $(or $(OUTPUT),.) -name '\.*.o.d' -delete
+ find $(or $(OUTPUT),.) -name '\.*.o.cmd' -delete
+
+install: $(ALL_PROGRAMS)
+ install -d -m 755 $(DESTDIR)$(bindir); \
+ for program in $(ALL_PROGRAMS); do \
+ install $$program $(DESTDIR)$(bindir); \
+ done
+
+FORCE:
+
+.PHONY: all install clean FORCE prepare
diff --git a/tools/i3c/i3ctransfer.c b/tools/i3c/i3ctransfer.c
new file mode 100644
index 000000000000..a5b071e63530
--- /dev/null
+++ b/tools/i3c/i3ctransfer.c
@@ -0,0 +1,307 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2019 Synopsys, Inc. and/or its affiliates.
+ * Copyright (c) 2026 Google LLC
+ *
+ * Author: Vitor Soares <vitor.soares@synopsys.com>
+ */
+
+#include <ctype.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <getopt.h>
+#include <limits.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include <linux/i3c/i3cdev.h>
+
+#define VERSION "0.2"
+
+static const char *sopts = "d:m:c:r:w:vh";
+static const struct option lopts[] = {
+ {"device", required_argument, NULL, 'd' },
+ {"mode", required_argument, NULL, 'm' },
+ {"command", required_argument, NULL, 'c' },
+ {"read", required_argument, NULL, 'r' },
+ {"write", required_argument, NULL, 'w' },
+ {"help", no_argument, NULL, 'h' },
+ {"version", no_argument, NULL, 'v' },
+ {0, 0, 0, 0}
+};
+
+static void print_usage(const char *name)
+{
+ fprintf(stderr, "usage: %s options...\n", name);
+ fprintf(stderr, " options:\n");
+ fprintf(stderr, " -d --device <dev> device to use.\n");
+ fprintf(stderr,
+ " -m --mode <mode> sdr (default), hdr-ddr, hdr-tsp, hdr-tsl.\n");
+ fprintf(stderr,
+ " -c --command <cmd> HDR command byte (0x00-0x7f W, 0x80-0xff R).\n");
+ fprintf(stderr, " -r --read <len> read data length in bytes.\n");
+ fprintf(stderr,
+ " -w --write <block> write comma-separated bytes (e.g. 0x01,0x02).\n");
+ fprintf(stderr, " -h --help output usage message and exit.\n");
+ fprintf(stderr, " -v --version output version number and exit.\n");
+}
+
+static int parse_mode(const char *arg, uint8_t *mode)
+{
+ char *endptr;
+ long val;
+
+ if (!strcmp(arg, "sdr")) {
+ *mode = I3C_XFER_MODE_SDR;
+ return 0;
+ }
+ if (!strcmp(arg, "hdr-ddr") || !strcmp(arg, "ddr")) {
+ *mode = I3C_XFER_MODE_HDR_DDR;
+ return 0;
+ }
+ if (!strcmp(arg, "hdr-tsp") || !strcmp(arg, "tsp")) {
+ *mode = I3C_XFER_MODE_HDR_TSP;
+ return 0;
+ }
+ if (!strcmp(arg, "hdr-tsl") || !strcmp(arg, "tsl")) {
+ *mode = I3C_XFER_MODE_HDR_TSL;
+ return 0;
+ }
+
+ val = strtol(arg, &endptr, 0);
+ if (*endptr == '\0' &&
+ (val == I3C_XFER_MODE_HDR_DDR ||
+ val == I3C_XFER_MODE_HDR_TSP ||
+ val == I3C_XFER_MODE_HDR_TSL ||
+ val == I3C_XFER_MODE_SDR)) {
+ *mode = (uint8_t)val;
+ return 0;
+ }
+
+ fprintf(stderr, "Error: invalid transfer mode '%s'\n", arg);
+ return -1;
+}
+
+static int rx_args_to_xfer(struct i3c_ioc_xfer *xfer, char *arg,
+ uint8_t mode, int cmd)
+{
+ char *endptr;
+ uint8_t *tmp;
+ long len;
+
+ len = strtol(arg, &endptr, 0);
+ if (*endptr != '\0' || len <= 0 || len > UINT16_MAX) {
+ fprintf(stderr, "Error: invalid read length '%s'\n", arg);
+ return -1;
+ }
+
+ if (mode == I3C_XFER_MODE_SDR) {
+ xfer->rnw = I3C_DEV_DIR_READ;
+ } else {
+ if (cmd < 0 || !(cmd & 0x80)) {
+ fprintf(stderr,
+ "Error: HDR read requires command (-c) in range 0x80..0xff\n");
+ return -1;
+ }
+ xfer->cmd = (uint8_t)cmd;
+ }
+
+ tmp = calloc(len, sizeof(uint8_t));
+ if (!tmp)
+ return -1;
+
+ xfer->mode = mode;
+ xfer->len = (uint16_t)len;
+ xfer->data = (uintptr_t)tmp;
+
+ return 0;
+}
+
+static int w_args_to_xfer(struct i3c_ioc_xfer *xfer, char *arg,
+ uint8_t mode, int cmd)
+{
+ char *data_ptrs[256];
+ int len, i = 0;
+ uint8_t *tmp;
+
+ if (mode == I3C_XFER_MODE_SDR) {
+ xfer->rnw = I3C_DEV_DIR_WRITE;
+ } else {
+ if (cmd < 0 || (cmd & 0x80)) {
+ fprintf(stderr,
+ "Error: HDR write requires command (-c) in range 0x00..0x7f\n");
+ return -1;
+ }
+ xfer->cmd = (uint8_t)cmd;
+ }
+
+ data_ptrs[i] = strtok(arg, ",");
+ while (data_ptrs[i] && i < 255)
+ data_ptrs[++i] = strtok(NULL, ",");
+
+ if (i == 0) {
+ fprintf(stderr, "Error: empty write data block\n");
+ return -1;
+ }
+
+ tmp = calloc(i, sizeof(uint8_t));
+ if (!tmp)
+ return -1;
+
+ for (len = 0; len < i; len++) {
+ char *endptr;
+ long val = strtol(data_ptrs[len], &endptr, 0);
+
+ if (*endptr != '\0' || val < 0 || val > UINT8_MAX) {
+ fprintf(stderr, "Error: invalid byte value '%s'\n",
+ data_ptrs[len]);
+ free(tmp);
+ return -1;
+ }
+ tmp[len] = (uint8_t)val;
+ }
+
+ xfer->mode = mode;
+ xfer->len = (uint16_t)len;
+ xfer->data = (uintptr_t)tmp;
+
+ return 0;
+}
+
+static void print_rx_data(const struct i3c_ioc_xfer *xfer)
+{
+ const uint8_t *tmp = (const uint8_t *)(uintptr_t)xfer->data;
+ int i;
+
+ fprintf(stdout, " received data (%u bytes):\n", xfer->actual_len);
+ for (i = 0; i < xfer->actual_len; i++)
+ fprintf(stdout, " 0x%02x\n", tmp[i]);
+}
+
+int main(int argc, char *argv[])
+{
+ uint8_t mode = I3C_XFER_MODE_SDR;
+ struct i3c_ioc_xfer *xfers;
+ char *device = NULL;
+ int file, ret, opt, i;
+ int nxfers = 0;
+ int cmd = -1;
+
+ while ((opt = getopt_long(argc, argv, sopts, lopts, NULL)) != EOF) {
+ switch (opt) {
+ case 'h':
+ print_usage(argv[0]);
+ return EXIT_SUCCESS;
+ case 'v':
+ fprintf(stderr, "%s - %s\n", argv[0], VERSION);
+ return EXIT_SUCCESS;
+ case 'd':
+ device = optarg;
+ break;
+ case 'm':
+ if (parse_mode(optarg, &mode))
+ return EXIT_FAILURE;
+ break;
+ case 'c': {
+ char *endptr;
+ long val = strtol(optarg, &endptr, 0);
+
+ if (*endptr != '\0' || val < 0 || val > UINT8_MAX) {
+ fprintf(stderr, "Error: invalid command '%s'\n",
+ optarg);
+ return EXIT_FAILURE;
+ }
+ cmd = (int)val;
+ break;
+ }
+ case 'r':
+ case 'w':
+ nxfers++;
+ break;
+ default:
+ print_usage(argv[0]);
+ return EXIT_FAILURE;
+ }
+ }
+
+ if (!device || nxfers == 0) {
+ print_usage(argv[0]);
+ return EXIT_FAILURE;
+ }
+
+ file = open(device, O_RDWR);
+ if (file < 0) {
+ fprintf(stderr, "Error: failed to open %s: %s\n",
+ device, strerror(errno));
+ return EXIT_FAILURE;
+ }
+
+ xfers = calloc(nxfers, sizeof(*xfers));
+ if (!xfers) {
+ close(file);
+ return EXIT_FAILURE;
+ }
+
+ optind = 1;
+ nxfers = 0;
+ cmd = -1;
+
+ while ((opt = getopt_long(argc, argv, sopts, lopts, NULL)) != EOF) {
+ switch (opt) {
+ case 'h':
+ case 'v':
+ case 'd':
+ case 'm':
+ break;
+ case 'c':
+ cmd = (int)strtol(optarg, NULL, 0);
+ break;
+ case 'r':
+ if (rx_args_to_xfer(&xfers[nxfers], optarg, mode, cmd)) {
+ ret = EXIT_FAILURE;
+ goto err_free;
+ }
+ nxfers++;
+ break;
+ case 'w':
+ if (w_args_to_xfer(&xfers[nxfers], optarg, mode, cmd)) {
+ ret = EXIT_FAILURE;
+ goto err_free;
+ }
+ nxfers++;
+ break;
+ }
+ }
+
+ if (ioctl(file, I3C_IOC_XFER(nxfers), xfers) < 0) {
+ fprintf(stderr, "Error: transfer failed: %s\n", strerror(errno));
+ ret = EXIT_FAILURE;
+ goto err_free;
+ }
+
+ for (i = 0; i < nxfers; i++) {
+ bool is_read = (mode == I3C_XFER_MODE_SDR) ?
+ (xfers[i].rnw == I3C_DEV_DIR_READ) :
+ (xfers[i].cmd & 0x80);
+
+ fprintf(stdout, "Success on message %d\n", i);
+ if (is_read)
+ print_rx_data(&xfers[i]);
+ }
+
+ ret = EXIT_SUCCESS;
+
+err_free:
+ for (i = 0; i < nxfers; i++)
+ free((void *)(uintptr_t)xfers[i].data);
+ free(xfers);
+ close(file);
+
+ return ret;
+}
--
2.55.0.1082.g2b9226bbc0-goog
^ permalink raw reply [flat|nested] 7+ messages in thread