[5/5] soundwire: qcom: add sdw_master_device support
diff mbox series

Message ID 20200320162947.17663-6-pierre-louis.bossart@linux.intel.com
State New
Headers show
Series
  • soundwire: add sdw_master_device support on Qualcomm platforms
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Commit Message

Pierre-Louis Bossart March 20, 2020, 4:29 p.m. UTC
Add new device as a child of the platform device, following the
following hierarchy:

platform_device
    sdw_master_device
        sdw_slave0
	...
	sdw_slaveN

For the Qualcomm implementation no sdw_master_driver is registered so
the dais have to be registered using the platform_device and likely
all power management is handled at the platform device level.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
---
 drivers/soundwire/qcom.c | 29 +++++++++++++++++++++++++----
 1 file changed, 25 insertions(+), 4 deletions(-)

Comments

Srinivas Kandagatla March 20, 2020, 5:01 p.m. UTC | #1
On 20/03/2020 16:29, Pierre-Louis Bossart wrote:
> Add new device as a child of the platform device, following the
> following hierarchy:
> 
> platform_device
>      sdw_master_device
>          sdw_slave0

Why can't we just remove the platform device layer here and add 
sdw_master_device directly?

What is it stopping doing that?

--srini


> 	...
> 	sdw_slaveN
> 
> For the Qualcomm implementation no sdw_master_driver is registered so
> the dais have to be registered using the platform_device and likely
> all power management is handled at the platform device level.
> 
> Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
> ---
>   drivers/soundwire/qcom.c | 29 +++++++++++++++++++++++++----
>   1 file changed, 25 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/soundwire/qcom.c b/drivers/soundwire/qcom.c
> index 77783ae4b71d..86b46415e50b 100644
> --- a/drivers/soundwire/qcom.c
> +++ b/drivers/soundwire/qcom.c
> @@ -89,6 +89,7 @@ struct qcom_swrm_port_config {
>   struct qcom_swrm_ctrl {
>   	struct sdw_bus bus;
>   	struct device *dev;
> +	struct sdw_master_device *md;
>   	struct regmap *regmap;
>   	struct completion *comp;
>   	struct work_struct slave_work;
> @@ -775,14 +776,31 @@ static int qcom_swrm_probe(struct platform_device *pdev)
>   	mutex_init(&ctrl->port_lock);
>   	INIT_WORK(&ctrl->slave_work, qcom_swrm_slave_wq);
>   
> -	ctrl->bus.dev = dev;
> +	/*
> +	 * add sdw_master_device.
> +	 * For the Qualcomm implementation there is no driver.
> +	 */
> +	ctrl->md = sdw_master_device_add(NULL,	/* no driver name */
> +					 dev,	/* platform device is parent */
> +					 dev->fwnode,
> +					 0,	/* only one link supported */
> +					 NULL);	/* no context */
> +	if (IS_ERR(ctrl->md)) {
> +		dev_err(dev, "Could not create sdw_master_device\n");
> +		ret = PTR_ERR(ctrl->md);
> +		goto err_clk;
> +	}
> +
> +	/* the bus uses the sdw_master_device, not the platform device */
> +	ctrl->bus.dev = &ctrl->md->dev;
> +
>   	ctrl->bus.ops = &qcom_swrm_ops;
>   	ctrl->bus.port_ops = &qcom_swrm_port_ops;
>   	ctrl->bus.compute_params = &qcom_swrm_compute_params;
>   
>   	ret = qcom_swrm_get_port_config(ctrl);
>   	if (ret)
> -		goto err_clk;
> +		goto err_md;
>   
>   	params = &ctrl->bus.params;
>   	params->max_dr_freq = DEFAULT_CLK_FREQ;
> @@ -809,14 +827,14 @@ static int qcom_swrm_probe(struct platform_device *pdev)
>   					"soundwire", ctrl);
>   	if (ret) {
>   		dev_err(dev, "Failed to request soundwire irq\n");
> -		goto err_clk;
> +		goto err_md;
>   	}
>   
>   	ret = sdw_add_bus_master(&ctrl->bus);
>   	if (ret) {
>   		dev_err(dev, "Failed to register Soundwire controller (%d)\n",
>   			ret);
> -		goto err_clk;
> +		goto err_md;
>   	}
>   
>   	qcom_swrm_init(ctrl);
> @@ -832,6 +850,8 @@ static int qcom_swrm_probe(struct platform_device *pdev)
>   
>   err_master_add:
>   	sdw_delete_bus_master(&ctrl->bus);
> +err_md:
> +	device_unregister(&ctrl->md->dev);
>   err_clk:
>   	clk_disable_unprepare(ctrl->hclk);
>   err_init:
> @@ -843,6 +863,7 @@ static int qcom_swrm_remove(struct platform_device *pdev)
>   	struct qcom_swrm_ctrl *ctrl = dev_get_drvdata(&pdev->dev);
>   
>   	sdw_delete_bus_master(&ctrl->bus);
> +	device_unregister(&ctrl->md->dev);
>   	clk_disable_unprepare(ctrl->hclk);
>   
>   	return 0;
>
Pierre-Louis Bossart March 20, 2020, 5:57 p.m. UTC | #2
>> Add new device as a child of the platform device, following the
>> following hierarchy:
>>
>> platform_device
>>      sdw_master_device
>>          sdw_slave0
> 
> Why can't we just remove the platform device layer here and add 
> sdw_master_device directly?
> 
> What is it stopping doing that?

The guidance from Greg was "no platform devices, unless you really are 
on a platform bus (i.e. Device tree.)". We never discussed changing the 
way the Device Tree parts are handled.

The main idea was to leave the parent (be it platform-device or PCI 
device) alone and not add new attributes or references to it.

The scheme here is similar to I2C/SPI, you have a platform device 
handled by the Device Tree baseline, and a driver create an 
i2c_adapter/spi_controller/sdw_master_device.
Vinod Koul March 23, 2020, 12:52 p.m. UTC | #3
On 20-03-20, 17:01, Srinivas Kandagatla wrote:
> 
> 
> On 20/03/2020 16:29, Pierre-Louis Bossart wrote:
> > Add new device as a child of the platform device, following the
> > following hierarchy:
> > 
> > platform_device
> >      sdw_master_device
> >          sdw_slave0
> 
> Why can't we just remove the platform device layer here and add
> sdw_master_device directly?

In the case platform_device is the OF device your controller gets probed
on.

My thinking on this is that drivers should not be directly creating
sdw_master_device but it should be done by core as this device is for
core to use and handle. Ideally I would love that sdw_master_device is
created/handled by core, preferably this be handled as part of
sdw_add_bus_master().

But Pierre is trying to solve the limitation of the devices given by
ACPI and trying to add sdw_master_driver to handle that. I am not
convinced that we should do that.

Patch
diff mbox series

diff --git a/drivers/soundwire/qcom.c b/drivers/soundwire/qcom.c
index 77783ae4b71d..86b46415e50b 100644
--- a/drivers/soundwire/qcom.c
+++ b/drivers/soundwire/qcom.c
@@ -89,6 +89,7 @@  struct qcom_swrm_port_config {
 struct qcom_swrm_ctrl {
 	struct sdw_bus bus;
 	struct device *dev;
+	struct sdw_master_device *md;
 	struct regmap *regmap;
 	struct completion *comp;
 	struct work_struct slave_work;
@@ -775,14 +776,31 @@  static int qcom_swrm_probe(struct platform_device *pdev)
 	mutex_init(&ctrl->port_lock);
 	INIT_WORK(&ctrl->slave_work, qcom_swrm_slave_wq);
 
-	ctrl->bus.dev = dev;
+	/*
+	 * add sdw_master_device.
+	 * For the Qualcomm implementation there is no driver.
+	 */
+	ctrl->md = sdw_master_device_add(NULL,	/* no driver name */
+					 dev,	/* platform device is parent */
+					 dev->fwnode,
+					 0,	/* only one link supported */
+					 NULL);	/* no context */
+	if (IS_ERR(ctrl->md)) {
+		dev_err(dev, "Could not create sdw_master_device\n");
+		ret = PTR_ERR(ctrl->md);
+		goto err_clk;
+	}
+
+	/* the bus uses the sdw_master_device, not the platform device */
+	ctrl->bus.dev = &ctrl->md->dev;
+
 	ctrl->bus.ops = &qcom_swrm_ops;
 	ctrl->bus.port_ops = &qcom_swrm_port_ops;
 	ctrl->bus.compute_params = &qcom_swrm_compute_params;
 
 	ret = qcom_swrm_get_port_config(ctrl);
 	if (ret)
-		goto err_clk;
+		goto err_md;
 
 	params = &ctrl->bus.params;
 	params->max_dr_freq = DEFAULT_CLK_FREQ;
@@ -809,14 +827,14 @@  static int qcom_swrm_probe(struct platform_device *pdev)
 					"soundwire", ctrl);
 	if (ret) {
 		dev_err(dev, "Failed to request soundwire irq\n");
-		goto err_clk;
+		goto err_md;
 	}
 
 	ret = sdw_add_bus_master(&ctrl->bus);
 	if (ret) {
 		dev_err(dev, "Failed to register Soundwire controller (%d)\n",
 			ret);
-		goto err_clk;
+		goto err_md;
 	}
 
 	qcom_swrm_init(ctrl);
@@ -832,6 +850,8 @@  static int qcom_swrm_probe(struct platform_device *pdev)
 
 err_master_add:
 	sdw_delete_bus_master(&ctrl->bus);
+err_md:
+	device_unregister(&ctrl->md->dev);
 err_clk:
 	clk_disable_unprepare(ctrl->hclk);
 err_init:
@@ -843,6 +863,7 @@  static int qcom_swrm_remove(struct platform_device *pdev)
 	struct qcom_swrm_ctrl *ctrl = dev_get_drvdata(&pdev->dev);
 
 	sdw_delete_bus_master(&ctrl->bus);
+	device_unregister(&ctrl->md->dev);
 	clk_disable_unprepare(ctrl->hclk);
 
 	return 0;