soundwire: qcom: add software workaround for bus clash interrupt assertion

Sometimes Hard reset does not clear some of the registers,
this sometimes results in firing a bus clash interrupt.
Add workaround for this during power up sequence, as
suggested by hardware manual.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20230525133812.30841-4-srinivas.kandagatla@linaro.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>

diff --git a/drivers/soundwire/qcom.c b/drivers/soundwire/qcom.c
index 91d9de5..488a9c0 100644 (file)
--- a/drivers/soundwire/qcom.c
+++ b/drivers/soundwire/qcom.c
@@ -790,6 +790,26 @@ static irqreturn_t qcom_swrm_irq_handler(int irq, void *dev_id)
        return ret;
 }
 
+static bool swrm_wait_for_frame_gen_enabled(struct qcom_swrm_ctrl *ctrl)
+{
+       int retry = SWRM_LINK_STATUS_RETRY_CNT;
+       int comp_sts;
+
+       do {
+               ctrl->reg_read(ctrl, SWRM_COMP_STATUS, &comp_sts);
+
+               if (comp_sts & SWRM_FRM_GEN_ENABLED)
+                       return true;
+
+               usleep_range(500, 510);
+       } while (retry--);
+
+       dev_err(ctrl->dev, "%s: link status not %s\n", __func__,
+               comp_sts & SWRM_FRM_GEN_ENABLED ? "connected" : "disconnected");
+
+       return false;
+}
+
 static int qcom_swrm_init(struct qcom_swrm_ctrl *ctrl)
 {
        u32 val;
@@ -838,16 +858,28 @@ static int qcom_swrm_init(struct qcom_swrm_ctrl *ctrl)
                                SWRM_RD_WR_CMD_RETRIES);
        }
 
+       /* COMP Enable */
+       ctrl->reg_write(ctrl, SWRM_COMP_CFG_ADDR, SWRM_COMP_CFG_ENABLE_MSK);
+
        /* Set IRQ to PULSE */
        ctrl->reg_write(ctrl, SWRM_COMP_CFG_ADDR,
-                       SWRM_COMP_CFG_IRQ_LEVEL_OR_PULSE_MSK |
-                       SWRM_COMP_CFG_ENABLE_MSK);
+                       SWRM_COMP_CFG_IRQ_LEVEL_OR_PULSE_MSK);
+
+       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);
        }
+
+       /* Set IRQ to PULSE */
+       ctrl->reg_write(ctrl, SWRM_COMP_CFG_ADDR,
+                       SWRM_COMP_CFG_IRQ_LEVEL_OR_PULSE_MSK |
+                       SWRM_COMP_CFG_ENABLE_MSK);
+
+       swrm_wait_for_frame_gen_enabled(ctrl);
        ctrl->slave_status = 0;
        ctrl->reg_read(ctrl, SWRM_COMP_PARAMS, &val);
        ctrl->rd_fifo_depth = FIELD_GET(SWRM_COMP_PARAMS_RD_FIFO_DEPTH, val);
@@ -1623,26 +1655,6 @@ static int qcom_swrm_remove(struct platform_device *pdev)
        return 0;
 }
 
-static bool swrm_wait_for_frame_gen_enabled(struct qcom_swrm_ctrl *ctrl)
-{
-       int retry = SWRM_LINK_STATUS_RETRY_CNT;
-       int comp_sts;
-
-       do {
-               ctrl->reg_read(ctrl, SWRM_COMP_STATUS, &comp_sts);
-
-               if (comp_sts & SWRM_FRM_GEN_ENABLED)
-                       return true;
-
-               usleep_range(500, 510);
-       } while (retry--);
-
-       dev_err(ctrl->dev, "%s: link status not %s\n", __func__,
-               comp_sts & SWRM_FRM_GEN_ENABLED ? "connected" : "disconnected");
-
-       return false;
-}
-
 static int __maybe_unused swrm_runtime_resume(struct device *dev)
 {
        struct qcom_swrm_ctrl *ctrl = dev_get_drvdata(dev);