Hi Uwe,
(CC'ing Bartosz)
Thank you for the patch.
On Tue, Nov 21, 2023 at 02:50:43PM +0100, Uwe Kleine-König wrote:
> This prepares the pwm driver of the ti-sn65dsi86 to further changes of
> the pwm core outlined in the commit introducing devm_pwmchip_alloc().
> There is no intended semantical change and the driver should behave as
> before.
>
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>
> ---
> drivers/gpu/drm/bridge/ti-sn65dsi86.c | 25 ++++++++++++++++---------
> 1 file changed, 16 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c
> index c45c07840f64..cd40530ffd71 100644
> --- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c
> +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c
> @@ -197,7 +197,7 @@ struct ti_sn65dsi86 {
> DECLARE_BITMAP(gchip_output, SN_NUM_GPIOS);
> #endif
> #if defined(CONFIG_PWM)
> - struct pwm_chip pchip;
> + struct pwm_chip *pchip;
Dynamic allocation with devm_*() isn't the right solution for lifetime
issues related to cdev. See my talk at LPC 2022
(https://www.youtube.com/watch?v=kW8LHWlJPTU, slides at
https://lpc.events/event/16/contributions/1227/attachments/1103/2115/20220914-lpc-devm_kzalloc.pdf),
and Bartosz's talk at LPC 2023
(https://lpc.events/event/17/contributions/1627/attachments/1258/2725/Linux%20Plumbers%20Conference%202023.pdf).
> bool pwm_enabled;
> atomic_t pwm_pin_busy;
> #endif
> @@ -1372,7 +1372,8 @@ static void ti_sn_pwm_pin_release(struct ti_sn65dsi86 *pdata)
>
> static struct ti_sn65dsi86 *pwm_chip_to_ti_sn_bridge(struct pwm_chip *chip)
> {
> - return container_of(chip, struct ti_sn65dsi86, pchip);
> + struct ti_sn65dsi86 **pdata = pwmchip_priv(chip);
> + return *pdata;
> }
>
> static int ti_sn_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
> @@ -1585,22 +1586,28 @@ static const struct pwm_ops ti_sn_pwm_ops = {
> static int ti_sn_pwm_probe(struct auxiliary_device *adev,
> const struct auxiliary_device_id *id)
> {
> + struct pwm_chip *chip;
> struct ti_sn65dsi86 *pdata = dev_get_drvdata(adev->dev.parent);
>
> - pdata->pchip.dev = pdata->dev;
> - pdata->pchip.ops = &ti_sn_pwm_ops;
> - pdata->pchip.npwm = 1;
> - pdata->pchip.of_xlate = of_pwm_single_xlate;
> - pdata->pchip.of_pwm_n_cells = 1;
> + /* XXX: should this better use adev->dev instead of pdata->dev? */
> + pdata->pchip = chip = devm_pwmchip_alloc(pdata->dev, 1, sizeof(&pdata));
> + if (IS_ERR(chip))
> + return PTR_ERR(chip);
>
> - return pwmchip_add(&pdata->pchip);
> + *(struct ti_sn65dsi86 **)pwmchip_priv(chip) = pdata;
> +
> + chip->ops = &ti_sn_pwm_ops;
> + chip->of_xlate = of_pwm_single_xlate;
> + chip->of_pwm_n_cells = 1;
> +
> + return pwmchip_add(chip);
> }
>
> static void ti_sn_pwm_remove(struct auxiliary_device *adev)
> {
> struct ti_sn65dsi86 *pdata = dev_get_drvdata(adev->dev.parent);
>
> - pwmchip_remove(&pdata->pchip);
> + pwmchip_remove(pdata->pchip);
>
> if (pdata->pwm_enabled)
> pm_runtime_put_sync(pdata->dev);
--
Regards,
Laurent Pinchart
