On Mon, Nov 18, 2019 at 10:37:22AM +0100, Clément Péron wrote:
> New device tree bindings called the source clock of the module
> "mod" when several clocks are defined.
>
> Try to get a clock called "mod" if nothing is found try to get
> an unnamed clock.
>
> Signed-off-by: Clément Péron <peron.clem@xxxxxxxxx>
> ---
> drivers/pwm/pwm-sun4i.c | 29 +++++++++++++++++++++++++++--
> 1 file changed, 27 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/pwm/pwm-sun4i.c b/drivers/pwm/pwm-sun4i.c
> index c17935805690..bbb1ed194c0e 100644
> --- a/drivers/pwm/pwm-sun4i.c
> +++ b/drivers/pwm/pwm-sun4i.c
> @@ -362,9 +362,34 @@ static int sun4i_pwm_probe(struct platform_device *pdev)
> if (IS_ERR(pwm->base))
> return PTR_ERR(pwm->base);
>
> - pwm->clk = devm_clk_get(&pdev->dev, NULL);
> - if (IS_ERR(pwm->clk))
> + /*
> + * All hardware variants need a source clock that is divided and
> + * then feeds the counter that defines the output wave form. In the
> + * device tree this clock is either unnamed or called "mod".
> + * Some variants (e.g. H6) need another clock to access the
> + * hardware registers; this is called "bus".
> + * So we request "mod" first (and ignore the corner case that a
> + * parent provides a "mod" clock while the right one would be the
> + * unnamed one of the PWM device) and if this is not found we fall
> + * back to the first clock of the PWM.
> + */
> + pwm->clk = devm_clk_get_optional(&pdev->dev, "mod");
> + if (IS_ERR(pwm->clk)) {
> + if (PTR_ERR(pwm->rst) != -EPROBE_DEFER)
> + dev_err(&pdev->dev, "get clock failed %pe\n",
> + pwm->clk);
I think the line break isn't needed here. Unless I'm mistaken the final
; will end in column 80 which is fine.
> return PTR_ERR(pwm->clk);
> + }
> +
> + if (!pwm->clk) {
> + pwm->clk = devm_clk_get(&pdev->dev, NULL);
> + if (IS_ERR(pwm->clk)) {
> + if (PTR_ERR(pwm->rst) != -EPROBE_DEFER)
> + dev_err(&pdev->dev, "get clock failed %pe\n",
> + pwm->clk);
A different error message than above would be nice to be able to
distinguish the two cases.
Best regards
Uwe
--
Pengutronix e.K. | Uwe Kleine-König |
Industrial Linux Solutions | https://www.pengutronix.de/ |
