Re: [PATCH 4/7] mfd / platform: cros_ec: move debugfs attributes to its own driver.

Guenter Roeck
2018-11-22T18:52:06Z

On Thu, Nov 22, 2018 at 12:33:53PM +0100, Enric Balletbo i Serra wrote:
> The entire way how cros debugfs attibutes are created is broken.
> cros_ec_debugfs should be its own driver and its attributes should be
> associated with a debugfs driver not the mfd driver.
>
> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
> ---
>
> drivers/mfd/cros_ec_dev.c | 41 +------------------
> drivers/platform/chrome/Kconfig | 10 +++++
> drivers/platform/chrome/Makefile | 4 +-
> drivers/platform/chrome/cros_ec_debugfs.c | 49 ++++++++++++++++++-----
> include/linux/mfd/cros_ec.h | 6 ---
> 5 files changed, 53 insertions(+), 57 deletions(-)
>
> diff --git a/drivers/mfd/cros_ec_dev.c b/drivers/mfd/cros_ec_dev.c
> index 790dc28b93f0..8c7ee2a0b50a 100644
> --- a/drivers/mfd/cros_ec_dev.c
> +++ b/drivers/mfd/cros_ec_dev.c
> @@ -403,6 +403,7 @@ static const struct mfd_cell cros_usbpd_charger_cells[] = {
> };
>
> static const struct mfd_cell cros_ec_platform_cells[] = {
> + { .name = "cros-ec-debugfs" },
> { .name = "cros-ec-lightbar" },
> { .name = "cros-ec-vbc" },
> };
> @@ -496,9 +497,6 @@ static int ec_device_probe(struct platform_device *pdev)
> dev_err(ec->dev,
> "failed to add cros-ec platform devices: %d\n", retval);
>
> - if (cros_ec_debugfs_init(ec))
> - dev_warn(dev, "failed to create debugfs directory\n");
> -
> return 0;
>
> failed:
> @@ -510,61 +508,24 @@ static int ec_device_remove(struct platform_device *pdev)
> {
> struct cros_ec_dev *ec = dev_get_drvdata(&pdev->dev);
>
> - cros_ec_debugfs_remove(ec);
> -
> cdev_del(&ec->cdev);
> device_unregister(&ec->class_dev);
> return 0;
> }
>
> -static void ec_device_shutdown(struct platform_device *pdev)
> -{
> - struct cros_ec_dev *ec = dev_get_drvdata(&pdev->dev);
> -
> - /* Be sure to clear up debugfs delayed works */
> - cros_ec_debugfs_remove(ec);
> -}
> -
> static const struct platform_device_id cros_ec_id[] = {
> { DRV_NAME, 0 },
> { /* sentinel */ }
> };
> MODULE_DEVICE_TABLE(platform, cros_ec_id);
>
> -static __maybe_unused int ec_device_suspend(struct device *dev)
> -{
> - struct cros_ec_dev *ec = dev_get_drvdata(dev);
> -
> - cros_ec_debugfs_suspend(ec);
> -
> - return 0;
> -}
> -
> -static __maybe_unused int ec_device_resume(struct device *dev)
> -{
> - struct cros_ec_dev *ec = dev_get_drvdata(dev);
> -
> - cros_ec_debugfs_resume(ec);
> -
> - return 0;
> -}
> -
> -static const struct dev_pm_ops cros_ec_dev_pm_ops = {
> -#ifdef CONFIG_PM_SLEEP
> - .suspend = ec_device_suspend,
> - .resume = ec_device_resume,
> -#endif
> -};
> -
> static struct platform_driver cros_ec_dev_driver = {
> .driver = {
> .name = DRV_NAME,
> - .pm = &cros_ec_dev_pm_ops,
> },
> .id_table = cros_ec_id,
> .probe = ec_device_probe,
> .remove = ec_device_remove,
> - .shutdown = ec_device_shutdown,
> };
>
> static int __init cros_ec_dev_init(void)
> diff --git a/drivers/platform/chrome/Kconfig b/drivers/platform/chrome/Kconfig
> index 29bd9837d520..a1239d48c46f 100644
> --- a/drivers/platform/chrome/Kconfig
> +++ b/drivers/platform/chrome/Kconfig
> @@ -131,4 +131,14 @@ config CROS_EC_VBC
> To compile this driver as a module, choose M here: the
> module will be called cros_ec_vbc.
>
> +config CROS_EC_DEBUGFS
> + tristate "Export ChromeOS EC internals in DebugFS"
> + depends on MFD_CROS_EC_CHARDEV && DEBUG_FS

Maybe "default MFD_CROS_EC_CHARDEV" ?

> + help
> + This option exposes the ChromeOS EC device internals to
> + userspace.
> +
> + To compile this driver as a module, choose M here: the
> + module will be called cros_ec_debugfs.
> +
> endif # CHROMEOS_PLATFORMS
> diff --git a/drivers/platform/chrome/Makefile b/drivers/platform/chrome/Makefile
> index 4081b7179df7..12a5c4d18c17 100644
> --- a/drivers/platform/chrome/Makefile
> +++ b/drivers/platform/chrome/Makefile
> @@ -3,8 +3,7 @@
> obj-$(CONFIG_CHROMEOS_LAPTOP) += chromeos_laptop.o
> obj-$(CONFIG_CHROMEOS_PSTORE) += chromeos_pstore.o
> obj-$(CONFIG_CHROMEOS_TBMC) += chromeos_tbmc.o
> -cros_ec_ctl-objs := cros_ec_sysfs.o \
> - cros_ec_debugfs.o
> +cros_ec_ctl-objs := cros_ec_sysfs.o
> obj-$(CONFIG_CROS_EC_CTL) += cros_ec_ctl.o
> obj-$(CONFIG_CROS_EC_I2C) += cros_ec_i2c.o
> obj-$(CONFIG_CROS_EC_SPI) += cros_ec_spi.o
> @@ -15,3 +14,4 @@ obj-$(CONFIG_CROS_EC_PROTO) += cros_ec_proto.o
> obj-$(CONFIG_CROS_KBD_LED_BACKLIGHT) += cros_kbd_led_backlight.o
> obj-$(CONFIG_CROS_EC_LIGHTBAR) += cros_ec_lightbar.o
> obj-$(CONFIG_CROS_EC_VBC) += cros_ec_vbc.o
> +obj-$(CONFIG_CROS_EC_DEBUGFS) += cros_ec_debugfs.o
> diff --git a/drivers/platform/chrome/cros_ec_debugfs.c b/drivers/platform/chrome/cros_ec_debugfs.c
> index c62ee8e610a0..2ae385a27a1d 100644
> --- a/drivers/platform/chrome/cros_ec_debugfs.c
> +++ b/drivers/platform/chrome/cros_ec_debugfs.c
> @@ -23,12 +23,16 @@
> #include <linux/fs.h>
> #include <linux/mfd/cros_ec.h>
> #include <linux/mfd/cros_ec_commands.h>
> +#include <linux/module.h>
> #include <linux/mutex.h>
> +#include <linux/platform_device.h>
> #include <linux/poll.h>
> #include <linux/sched.h>
> #include <linux/slab.h>
> #include <linux/wait.h>
>
> +#define DRV_NAME "cros-ec-debugfs"
> +
> #define LOG_SHIFT 14
> #define LOG_SIZE (1 << LOG_SHIFT)
> #define LOG_POLL_SEC 10
> @@ -423,8 +427,9 @@ static int cros_ec_create_pdinfo(struct cros_ec_debugfs *debug_info)
> return 0;
> }
>
> -int cros_ec_debugfs_init(struct cros_ec_dev *ec)
> +static int cros_ec_debugfs_probe(struct platform_device *pd)
> {
> + struct cros_ec_dev *ec = dev_get_drvdata(pd->dev.parent);
> struct cros_ec_platform *ec_platform = dev_get_platdata(ec->dev);
> const char *name = ec_platform->ec_name;
> struct cros_ec_debugfs *debug_info;
> @@ -459,20 +464,24 @@ int cros_ec_debugfs_init(struct cros_ec_dev *ec)
> debugfs_remove_recursive(debug_info->dir);
> return ret;
> }
> -EXPORT_SYMBOL(cros_ec_debugfs_init);
>
> -void cros_ec_debugfs_remove(struct cros_ec_dev *ec)
> +static int cros_ec_debugfs_remove(struct platform_device *pd)
> {
> + struct cros_ec_dev *ec = dev_get_drvdata(pd->dev.parent);
> +
> if (!ec->debug_info)
> - return;
> + return 0;

This should no long be necessary.

>
> debugfs_remove_recursive(ec->debug_info->dir);
> cros_ec_cleanup_console_log(ec->debug_info);
> +
> + return 0;
> }
> -EXPORT_SYMBOL(cros_ec_debugfs_remove);
>
> -void cros_ec_debugfs_suspend(struct cros_ec_dev *ec)
> +static int __maybe_unused cros_ec_debugfs_suspend(struct device *dev)
> {
> + struct cros_ec_dev *ec = dev_get_drvdata(dev);
> +
> /*
> * cros_ec_debugfs_init() failures are non-fatal; it's also possible
> * that we initted things but decided that console log wasn't supported.

The above comment no longer applies. Also, since this is now its own driver,
the if statement should not be necessary anymore.

> @@ -481,12 +490,34 @@ void cros_ec_debugfs_suspend(struct cros_ec_dev *ec)
> */
> if (ec->debug_info && ec->debug_info->log_buffer.buf)
> cancel_delayed_work_sync(&ec->debug_info->log_poll_work);
> +
> + return 0;
> }
> -EXPORT_SYMBOL(cros_ec_debugfs_suspend);
>
> -void cros_ec_debugfs_resume(struct cros_ec_dev *ec)
> +static int __maybe_unused cros_ec_debugfs_resume(struct device *dev)
> {
> + struct cros_ec_dev *ec = dev_get_drvdata(dev);
> +
> if (ec->debug_info && ec->debug_info->log_buffer.buf)
> schedule_delayed_work(&ec->debug_info->log_poll_work, 0);

As aabove, the if statement should not be necessary anymore.

> +
> + return 0;
> }
> -EXPORT_SYMBOL(cros_ec_debugfs_resume);
> +
> +static SIMPLE_DEV_PM_OPS(cros_ec_debugfs_pm_ops,
> + cros_ec_debugfs_suspend, cros_ec_debugfs_resume);
> +
> +static struct platform_driver cros_ec_debugfs_driver = {
> + .driver = {
> + .name = DRV_NAME,
> + .pm = &cros_ec_debugfs_pm_ops,
> + },
> + .probe = cros_ec_debugfs_probe,
> + .remove = cros_ec_debugfs_remove,
> +};
> +
> +module_platform_driver(cros_ec_debugfs_driver);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_DESCRIPTION("Debug logs for ChromeOS EC");
> +MODULE_ALIAS("platform:" DRV_NAME);
> diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h
> index ddbb7e18a530..1722c2c26143 100644
> --- a/include/linux/mfd/cros_ec.h
> +++ b/include/linux/mfd/cros_ec.h
> @@ -336,12 +336,6 @@ u32 cros_ec_get_host_event(struct cros_ec_device *ec_dev);
> /* sysfs stuff */
> extern struct attribute_group cros_ec_attr_group;
>
> -/* debugfs stuff */
> -int cros_ec_debugfs_init(struct cros_ec_dev *ec);
> -void cros_ec_debugfs_remove(struct cros_ec_dev *ec);
> -void cros_ec_debugfs_suspend(struct cros_ec_dev *ec);
> -void cros_ec_debugfs_resume(struct cros_ec_dev *ec);
> -
> /* Attach/detach attributes to the cros_class */
> extern int cros_ec_attach_attribute_group(struct cros_ec_dev *ec,
> struct attribute_group *attrs);