diff mbox series

[v3,2/2] ASoC: qcom: soundwire: Add software clock gating requirement check

Message ID 1654696929-20205-3-git-send-email-quic_srivasam@quicinc.com (mailing list archive)
State Superseded
Headers show
Series Add software clock gating requirement check | expand

Commit Message

Srinivasa Rao Mandadapu June 8, 2022, 2:02 p.m. UTC 
Validate software clock gating required or not and do software
clock gating on hclk if soundwire is operational and keep it
running by adding flag in private dat structure.
This is to avoid conflict between older architectures,
where software clock gating is not required and on latest
architectues, where software clock gating is mandatory.

Signed-off-by: Srinivasa Rao Mandadapu <quic_srivasam@quicinc.com>
Reviewed-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
---
 drivers/soundwire/qcom.c | 27 ++++++++++++++++++++-------
 1 file changed, 20 insertions(+), 7 deletions(-)

Comments

Stephen Boyd June 8, 2022, 7:29 p.m. UTC | #1 
Quoting Srinivasa Rao Mandadapu (2022-06-08 07:02:09)
> Validate software clock gating required or not and do software
> clock gating on hclk if soundwire is operational and keep it
> running by adding flag in private dat structure.
> This is to avoid conflict between older architectures,
> where software clock gating is not required and on latest
> architectues, where software clock gating is mandatory.

This talks about software clock gating but the code is getting a reset
and asserting it. Is that because the power on reset value of the clock
gating is to have hardware clock gating disabled, but some earlier code
is enabling hardware clock gating?

>
> Signed-off-by: Srinivasa Rao Mandadapu <quic_srivasam@quicinc.com>
> Reviewed-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
> ---
>  drivers/soundwire/qcom.c | 27 ++++++++++++++++++++-------
>  1 file changed, 20 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/soundwire/qcom.c b/drivers/soundwire/qcom.c
> index 38c3bf5..ebd7479 100644
> --- a/drivers/soundwire/qcom.c
> +++ b/drivers/soundwire/qcom.c
> @@ -659,7 +665,8 @@ static int qcom_swrm_init(struct qcom_swrm_ctrl *ctrl)
>         val = FIELD_PREP(SWRM_MCP_FRAME_CTRL_BANK_ROW_CTRL_BMSK, ctrl->rows_index);
>         val |= FIELD_PREP(SWRM_MCP_FRAME_CTRL_BANK_COL_CTRL_BMSK, ctrl->cols_index);
>
> -       reset_control_reset(ctrl->audio_cgcr);
> +       if (ctrl->audio_cgcr)
> +               reset_control_reset(ctrl->audio_cgcr);
>
>         ctrl->reg_write(ctrl, SWRM_MCP_FRAME_CTRL_BANK_ADDR(0), val);
>
> @@ -1494,7 +1506,8 @@ static int __maybe_unused swrm_runtime_resume(struct device *dev)
>                 qcom_swrm_get_device_status(ctrl);
>                 sdw_handle_slave_status(&ctrl->bus, ctrl->status);
>         } else {
> -               reset_control_reset(ctrl->audio_cgcr);
> +               if (ctrl->audio_cgcr)
> +                       reset_control_reset(ctrl->audio_cgcr);

reset_control_reset() is a no-op if the pointer is NULL so the if
condition is not necessary in the above two statements.
Srinivasa Rao Mandadapu June 9, 2022, 5:14 a.m. UTC | #2 
On 6/9/2022 12:59 AM, Stephen Boyd wrote:
Thanks for Your time Stephen!!!
> Quoting Srinivasa Rao Mandadapu (2022-06-08 07:02:09)
>> Validate software clock gating required or not and do software
>> clock gating on hclk if soundwire is operational and keep it
>> running by adding flag in private dat structure.
>> This is to avoid conflict between older architectures,
>> where software clock gating is not required and on latest
>> architectues, where software clock gating is mandatory.
> This talks about software clock gating but the code is getting a reset
> and asserting it. Is that because the power on reset value of the clock
> gating is to have hardware clock gating disabled, but some earlier code
> is enabling hardware clock gating?

Yes Stephen. By Default this resets to HW controlled. As such there is 
no specific code

for enabling hardware clock gating, as these CGCR registers default 
setting is HW control.

>
>> Signed-off-by: Srinivasa Rao Mandadapu <quic_srivasam@quicinc.com>
>> Reviewed-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
>> ---
>>   drivers/soundwire/qcom.c | 27 ++++++++++++++++++++-------
>>   1 file changed, 20 insertions(+), 7 deletions(-)
>>
>> diff --git a/drivers/soundwire/qcom.c b/drivers/soundwire/qcom.c
>> index 38c3bf5..ebd7479 100644
>> --- a/drivers/soundwire/qcom.c
>> +++ b/drivers/soundwire/qcom.c
>> @@ -659,7 +665,8 @@ static int qcom_swrm_init(struct qcom_swrm_ctrl *ctrl)
>>          val = FIELD_PREP(SWRM_MCP_FRAME_CTRL_BANK_ROW_CTRL_BMSK, ctrl->rows_index);
>>          val |= FIELD_PREP(SWRM_MCP_FRAME_CTRL_BANK_COL_CTRL_BMSK, ctrl->cols_index);
>>
>> -       reset_control_reset(ctrl->audio_cgcr);
>> +       if (ctrl->audio_cgcr)
>> +               reset_control_reset(ctrl->audio_cgcr);
>>
>>          ctrl->reg_write(ctrl, SWRM_MCP_FRAME_CTRL_BANK_ADDR(0), val);
>>
>> @@ -1494,7 +1506,8 @@ static int __maybe_unused swrm_runtime_resume(struct device *dev)
>>                  qcom_swrm_get_device_status(ctrl);
>>                  sdw_handle_slave_status(&ctrl->bus, ctrl->status);
>>          } else {
>> -               reset_control_reset(ctrl->audio_cgcr);
>> +               if (ctrl->audio_cgcr)
>> +                       reset_control_reset(ctrl->audio_cgcr);
> reset_control_reset() is a no-op if the pointer is NULL so the if
> condition is not necessary in the above two statements.
Okay. revert this NULL check here.
diff mbox series

Patch

diff --git a/drivers/soundwire/qcom.c b/drivers/soundwire/qcom.c
index 38c3bf5..ebd7479 100644
--- a/drivers/soundwire/qcom.c
+++ b/drivers/soundwire/qcom.c
@@ -194,6 +194,12 @@  static const struct qcom_swrm_data swrm_v1_5_data = {
 	.default_cols = 16,
 };
 
+static const struct qcom_swrm_data swrm_v1_6_data = {
+	.default_rows = 50,
+	.default_cols = 16,
+	.sw_clk_gate_required = true,
+};
+
 #define to_qcom_sdw(b)	container_of(b, struct qcom_swrm_ctrl, bus)
 
 static int qcom_swrm_ahb_reg_read(struct qcom_swrm_ctrl *ctrl, int reg,
@@ -659,7 +665,8 @@  static int qcom_swrm_init(struct qcom_swrm_ctrl *ctrl)
 	val = FIELD_PREP(SWRM_MCP_FRAME_CTRL_BANK_ROW_CTRL_BMSK, ctrl->rows_index);
 	val |= FIELD_PREP(SWRM_MCP_FRAME_CTRL_BANK_COL_CTRL_BMSK, ctrl->cols_index);
 
-	reset_control_reset(ctrl->audio_cgcr);
+	if (ctrl->audio_cgcr)
+		reset_control_reset(ctrl->audio_cgcr);
 
 	ctrl->reg_write(ctrl, SWRM_MCP_FRAME_CTRL_BANK_ADDR(0), val);
 
@@ -1312,6 +1319,15 @@  static int qcom_swrm_probe(struct platform_device *pdev)
 			return PTR_ERR(ctrl->mmio);
 	}
 
+	if (data->sw_clk_gate_required) {
+		ctrl->audio_cgcr = devm_reset_control_get_exclusive(dev, "swr_audio_cgcr");
+		if (IS_ERR(ctrl->audio_cgcr)) {
+			dev_err(dev, "Failed to get cgcr reset ctrl required for SW gating\n");
+			ret = PTR_ERR(ctrl->audio_cgcr);
+			goto err_init;
+		}
+	}
+
 	ctrl->irq = of_irq_get(dev->of_node, 0);
 	if (ctrl->irq < 0) {
 		ret = ctrl->irq;
@@ -1337,10 +1353,6 @@  static int qcom_swrm_probe(struct platform_device *pdev)
 	ctrl->bus.compute_params = &qcom_swrm_compute_params;
 	ctrl->bus.clk_stop_timeout = 300;
 
-	ctrl->audio_cgcr = devm_reset_control_get_exclusive(dev, "swr_audio_cgcr");
-	if (IS_ERR(ctrl->audio_cgcr))
-		dev_err(dev, "Failed to get audio_cgcr reset required for soundwire-v1.6.0\n");
-
 	ret = qcom_swrm_get_port_config(ctrl);
 	if (ret)
 		goto err_clk;
@@ -1494,7 +1506,8 @@  static int __maybe_unused swrm_runtime_resume(struct device *dev)
 		qcom_swrm_get_device_status(ctrl);
 		sdw_handle_slave_status(&ctrl->bus, ctrl->status);
 	} else {
-		reset_control_reset(ctrl->audio_cgcr);
+		if (ctrl->audio_cgcr)
+			reset_control_reset(ctrl->audio_cgcr);
 
 		ctrl->reg_write(ctrl, SWRM_MCP_BUS_CTRL, SWRM_MCP_BUS_CLK_START);
 		ctrl->reg_write(ctrl, SWRM_INTERRUPT_CLEAR,
@@ -1559,7 +1572,7 @@  static const struct dev_pm_ops swrm_dev_pm_ops = {
 static const struct of_device_id qcom_swrm_of_match[] = {
 	{ .compatible = "qcom,soundwire-v1.3.0", .data = &swrm_v1_3_data },
 	{ .compatible = "qcom,soundwire-v1.5.1", .data = &swrm_v1_5_data },
-	{ .compatible = "qcom,soundwire-v1.6.0", .data = &swrm_v1_5_data },
+	{ .compatible = "qcom,soundwire-v1.6.0", .data = &swrm_v1_6_data },
 	{/* sentinel */},
 };