[PATCH v1 2/2] soundwire: qcom: add EE-aware register layout and cpu selection

[Mohammad Rafi Shaik <mohammad.rafi.shaik@oss.qualcomm.com>]

Some Qualcomm SoundWire masters expose interrupt, FIFO and status
registers in EE-specific register windows on v2.0 and newer hardware.

Add support for selecting the SoundWire execution environment from DT
and use it to program the correct register window for the active EE.
The driver now reads the EE value from the new
qcom,swr-master-ee-val property, with qcom,ee as a fallback for
backward compatibility.

For v2.0+ hardware, the IRQ/FIFO/status register layout is adjusted by
the EE window stride so the driver programs the correct bank for the
selected EE. The interrupt enable path is also updated to always use
the selected EE window.

This change allows SoundWire interrupt routing and register accesses to
work correctly on platforms where the master is not mapped to the
default EE1 window.

In Shikra, the soundwire execution environment is set to 0 unlike other
Qualcomm boards.

Signed-off-by: Mohammad Rafi Shaik <mohammad.rafi.shaik@oss.qualcomm.com>
---
 drivers/soundwire/qcom.c | 78 +++++++++++++++++++++++++++++++++-------
 1 file changed, 65 insertions(+), 13 deletions(-)

diff --git a/drivers/soundwire/qcom.c b/drivers/soundwire/qcom.c
index 3d8f5a81e..f4b8ff77b 100644
--- a/drivers/soundwire/qcom.c
+++ b/drivers/soundwire/qcom.c
@@ -26,6 +26,7 @@
 #define SWRM_COMP_STATUS					0x014
 #define SWRM_LINK_MANAGER_EE					0x018
 #define SWRM_EE_CPU						1
+#define SWRM_MAX_EE						1
 #define SWRM_FRM_GEN_ENABLED					BIT(0)
 #define SWRM_VERSION_1_3_0					0x01030000
 #define SWRM_VERSION_1_5_1					0x01050001
@@ -118,6 +119,7 @@
 #define SWRM_V2_0_CLK_CTRL					0x5060
 #define SWRM_V2_0_CLK_CTRL_CLK_START				BIT(0)
 #define SWRM_V2_0_LINK_STATUS					0x5064
+#define SWRM_V2_REG_EE_STRIDE					0x1000
 
 #define SWRM_DP_PORT_CTRL_EN_CHAN_SHFT				0x18
 #define SWRM_DP_PORT_CTRL_OFFSET2_SHFT				0x10
@@ -202,6 +204,7 @@ struct qcom_swrm_ctrl {
 	struct mutex port_lock;
 	struct clk *hclk;
 	int irq;
+	u32 ee;
 	unsigned int version;
 	int wake_irq;
 	int num_din_ports;
@@ -222,6 +225,7 @@ struct qcom_swrm_ctrl {
 	u32 slave_status;
 	u32 wr_fifo_depth;
 	bool clock_stop_not_supported;
+	unsigned int reg_layout_local[SWRM_OFFSET_DP_SAMPLECTRL2_BANK + 1];
 };
 
 struct qcom_swrm_data {
@@ -328,6 +332,36 @@ static const struct qcom_swrm_data swrm_v3_0_data = {
 };
 #define to_qcom_sdw(b)	container_of(b, struct qcom_swrm_ctrl, bus)
 
+static void qcom_swrm_set_ee_register_layout(struct qcom_swrm_ctrl *ctrl,
+					     const struct qcom_swrm_data *data)
+{
+	int ee_offset;
+
+	memcpy(ctrl->reg_layout_local, data->reg_layout,
+	       sizeof(ctrl->reg_layout_local));
+	ctrl->reg_layout = ctrl->reg_layout_local;
+
+	if (ctrl->version < SWRM_VERSION_2_0_0)
+		return;
+
+	/*
+	 * Current register constants map EE1. For EE0, use the EE register
+	 * window stride to access status/IRQ/FIFO registers.
+	 */
+	ee_offset = ((int)ctrl->ee - SWRM_EE_CPU) * SWRM_V2_REG_EE_STRIDE;
+	if (!ee_offset)
+		return;
+
+	ctrl->reg_layout_local[SWRM_REG_FRAME_GEN_ENABLED] += ee_offset;
+	ctrl->reg_layout_local[SWRM_REG_INTERRUPT_STATUS] += ee_offset;
+	ctrl->reg_layout_local[SWRM_REG_INTERRUPT_CLEAR] += ee_offset;
+	ctrl->reg_layout_local[SWRM_REG_INTERRUPT_CPU_EN] += ee_offset;
+	ctrl->reg_layout_local[SWRM_REG_CMD_FIFO_WR_CMD] += ee_offset;
+	ctrl->reg_layout_local[SWRM_REG_CMD_FIFO_RD_CMD] += ee_offset;
+	ctrl->reg_layout_local[SWRM_REG_CMD_FIFO_STATUS] += ee_offset;
+	ctrl->reg_layout_local[SWRM_REG_CMD_FIFO_RD_FIFO_ADDR] += ee_offset;
+}
+
 static int qcom_swrm_ahb_reg_read(struct qcom_swrm_ctrl *ctrl, int reg,
 				  u32 *val)
 {
@@ -904,12 +938,13 @@ static int qcom_swrm_init(struct qcom_swrm_ctrl *ctrl)
 	ctrl->reg_write(ctrl, SWRM_MCP_CFG_ADDR, val);
 
 	if (ctrl->version == SWRM_VERSION_1_7_0) {
-		ctrl->reg_write(ctrl, SWRM_LINK_MANAGER_EE, SWRM_EE_CPU);
+		ctrl->reg_write(ctrl, SWRM_LINK_MANAGER_EE, ctrl->ee);
 		ctrl->reg_write(ctrl, SWRM_MCP_BUS_CTRL,
-				SWRM_MCP_BUS_CLK_START << SWRM_EE_CPU);
+				SWRM_MCP_BUS_CLK_START << ctrl->ee);
 	} else if (ctrl->version >= SWRM_VERSION_2_0_0) {
-		ctrl->reg_write(ctrl, SWRM_LINK_MANAGER_EE, SWRM_EE_CPU);
-		ctrl->reg_write(ctrl, SWRM_V2_0_CLK_CTRL,
+		ctrl->reg_write(ctrl, SWRM_LINK_MANAGER_EE, ctrl->ee);
+		ctrl->reg_write(ctrl, SWRM_V2_0_CLK_CTRL +
+				((int)ctrl->ee - SWRM_EE_CPU) * SWRM_V2_REG_EE_STRIDE,
 				SWRM_V2_0_CLK_CTRL_CLK_START);
 	} else {
 		ctrl->reg_write(ctrl, SWRM_MCP_BUS_CTRL, SWRM_MCP_BUS_CLK_START);
@@ -935,11 +970,9 @@ static int qcom_swrm_init(struct qcom_swrm_ctrl *ctrl)
 	ctrl->reg_write(ctrl, ctrl->reg_layout[SWRM_REG_INTERRUPT_CLEAR],
 			0xFFFFFFFF);
 
-	/* enable CPU IRQs */
-	if (ctrl->mmio) {
-		ctrl->reg_write(ctrl, ctrl->reg_layout[SWRM_REG_INTERRUPT_CPU_EN],
-				SWRM_INTERRUPT_STATUS_RMSK);
-	}
+	/* enable CPU IRQs for the selected EE window */
+	ctrl->reg_write(ctrl, ctrl->reg_layout[SWRM_REG_INTERRUPT_CPU_EN],
+			SWRM_INTERRUPT_STATUS_RMSK);
 
 	/* Set IRQ to PULSE */
 	ctrl->reg_write(ctrl, SWRM_COMP_CFG_ADDR,
@@ -1545,7 +1578,22 @@ static int qcom_swrm_probe(struct platform_device *pdev)
 		return -ENOMEM;
 
 	data = of_device_get_match_data(dev);
+	ctrl->ee = SWRM_EE_CPU;
+	ret = of_property_read_u32(dev->of_node, "qcom,swr-master-ee-val", &ctrl->ee);
+	if (ret)
+		ret = of_property_read_u32(dev->of_node, "qcom,ee", &ctrl->ee);
+	if (ret)
+		ctrl->ee = SWRM_EE_CPU;
+	if (ctrl->ee > SWRM_MAX_EE) {
+		dev_warn(dev, "invalid SoundWire EE %u, using EE%u\n",
+			 ctrl->ee, SWRM_EE_CPU);
+		ctrl->ee = SWRM_EE_CPU;
+	}
 	ctrl->max_reg = data->max_reg;
+	/*
+	 * Defer EE register window selection until HW version is known.
+	 * For v2.0+ the IRQ/FIFO window is EE-banked.
+	 */
 	ctrl->reg_layout = data->reg_layout;
 	ctrl->rows_index = sdw_find_row_index(data->default_rows);
 	ctrl->cols_index = sdw_find_col_index(data->default_cols);
@@ -1623,6 +1671,7 @@ static int qcom_swrm_probe(struct platform_device *pdev)
 	prop->default_row = data->default_rows;
 
 	ctrl->reg_read(ctrl, SWRM_COMP_HW_VERSION, &ctrl->version);
+	qcom_swrm_set_ee_register_layout(ctrl, data);
 
 	ret = devm_request_threaded_irq(dev, ctrl->irq, NULL,
 					qcom_swrm_irq_handler,
@@ -1733,16 +1782,19 @@ static int __maybe_unused swrm_runtime_resume(struct device *dev)
 		reset_control_reset(ctrl->audio_cgcr);
 
 		if (ctrl->version == SWRM_VERSION_1_7_0) {
-			ctrl->reg_write(ctrl, SWRM_LINK_MANAGER_EE, SWRM_EE_CPU);
+			ctrl->reg_write(ctrl, SWRM_LINK_MANAGER_EE, ctrl->ee);
 			ctrl->reg_write(ctrl, SWRM_MCP_BUS_CTRL,
-					SWRM_MCP_BUS_CLK_START << SWRM_EE_CPU);
+					SWRM_MCP_BUS_CLK_START << ctrl->ee);
 		} else if (ctrl->version >= SWRM_VERSION_2_0_0) {
-			ctrl->reg_write(ctrl, SWRM_LINK_MANAGER_EE, SWRM_EE_CPU);
-			ctrl->reg_write(ctrl, SWRM_V2_0_CLK_CTRL,
+			ctrl->reg_write(ctrl, SWRM_LINK_MANAGER_EE, ctrl->ee);
+			ctrl->reg_write(ctrl, SWRM_V2_0_CLK_CTRL +
+					((int)ctrl->ee - SWRM_EE_CPU) *
+					SWRM_V2_REG_EE_STRIDE,
 					SWRM_V2_0_CLK_CTRL_CLK_START);
 		} else {
 			ctrl->reg_write(ctrl, SWRM_MCP_BUS_CTRL, SWRM_MCP_BUS_CLK_START);
 		}
+
 		ctrl->reg_write(ctrl, ctrl->reg_layout[SWRM_REG_INTERRUPT_CLEAR],
 			SWRM_INTERRUPT_STATUS_MASTER_CLASH_DET);
 
-- 
2.34.1