On Wed, Dec 07, 2022 at 02:43:05PM +0200, Tony Lindgren wrote:
> We want to enable runtime PM for serial port device drivers in a generic
> way. To do this, we want to have the serial core layer manage the
> registered physical serial controller devices.
>
> To do this, let's set up a struct device for the serial core controller
> as suggested by Greg and Jiri. The serial core controller devices are
> children of the physical serial port device. The serial core controller
> device is needed to support multiple different kind of ports connected
> to single physical serial port device.
>
> Let's also set up a struct device for the serial core port. The serial
> core port instances are children of the serial core controller device.
> With the serial core port device we can now flush pending TX on the
> runtime PM resume as suggested by Johan.
...
> +static struct platform_device *serial_core_device_add(struct uart_port *port,
> + const char *name,
> + struct device *parent_dev,
> + void *pdata,
> + int pdata_size)
> +{
> + struct platform_device_info pinfo;
' = {}' can also work instead of memset(), but up to you.
> + memset(&pinfo, 0, sizeof(pinfo));
> + pinfo.name = name;
> + pinfo.id = PLATFORM_DEVID_AUTO;
> + pinfo.parent = parent_dev;
> + pinfo.data = pdata;
> + pinfo.size_data = pdata_size;
> +
> + return platform_device_register_full(&pinfo);
> +}
...
> + struct serial_port_platdata pdata;
Ditto.
> + memset(&pdata, 0, sizeof(pdata));
...
> +int serial_core_register_port(struct uart_driver *drv, struct uart_port *port)
> +{
> + bool allocated = false;
Not sure why this is needed.
> + struct device *ctrl_dev;
> + int ret;
> +
> + ret = serial_core_add_one_port(drv, port);
> + if (ret)
> + return ret;
> +
> + mutex_lock(&port_mutex);
> +
> + /* Inititalize a serial core controller device if needed */
> + ctrl_dev = serial_core_ctrl_find(drv, port->dev, port->ctrl_id);
> + if (!ctrl_dev) {
> + ctrl_dev = serial_core_ctrl_device_add(port);
> + if (!ctrl_dev)
> + goto err_remove_port;
> + allocated = true;
> + }
Wouldn't be slightly better
ctrl_dev = serial_core_ctrl_find(drv, port->dev, port->ctrl_id);
if (!ctrl_dev)
ctrl_dev = serial_core_ctrl_device_add(port);
if (!ctrl_dev)
goto err_remove_port;
?
> + /* Initialize a serial core port device */
> + ret = serial_core_port_device_add(ctrl_dev, port);
> + if (ret)
> + goto err_del_ctrl_dev;
> +
> + mutex_unlock(&port_mutex);
> +
> + return 0;
> +
> +err_del_ctrl_dev:
> + if (allocated)
> + platform_device_del(to_platform_device(ctrl_dev));
Shouldn't you call platform_device_unregister()?
> +err_remove_port:
> + mutex_unlock(&port_mutex);
> +
> + return serial_core_remove_one_port(drv, port);
> +}
...
> + platform_device_del(to_platform_device(port_dev));
Ditto?
...
> + /* Drop the serial core controller device if no ports are using it */
> + if (!serial_core_ctrl_find(drv, port->dev, port->ctrl_id))
> + platform_device_del(to_platform_device(ctrl_dev));
Ditto?
...
> +/* Serial core controller data. Serial port device drivers do not need this. */
Some missing forward declarations?
struct uart_driver:
struct uart_port;
?
...
> +static DEFINE_RUNTIME_DEV_PM_OPS(serial_port_pm, NULL,
> + serial_port_runtime_resume, NULL);
Wouldn't be more logical to indent like
static DEFINE_RUNTIME_DEV_PM_OPS(serial_port_pm,
NULL, serial_port_runtime_resume,
NULL);
?
--
With Best Regards,
Andy Shevchenko
