Re: [PATCH 1/5] pwm: mediatek: add a property "mediatek,num-pwms"

Uwe Kleine-König
2019-01-15T20:00:45Z

On Mon, Jan 14, 2019 at 04:21:20PM +0800, Ryder Lee wrote:
> This adds a property "mediatek,num-pwms" to avoid having an endless
> list of compatibles with no other differences for the same driver.

I seem to recall having said something similar before, but maybe this
was a different series (there is no v2 or higher in the Subject ...)

I think it would be sensible to drop the vendor prefix and go with plain
"num-pwms" (or "npwms" to align to "ngpios" in the gpio bindings).

> Signed-off-by: Ryder Lee <ryder.lee@mediatek.com>
> ---
> drivers/pwm/pwm-mediatek.c | 25 +++++++++++--------------
> 1 file changed, 11 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/pwm/pwm-mediatek.c b/drivers/pwm/pwm-mediatek.c
> index eb6674c..37daa84 100644
> --- a/drivers/pwm/pwm-mediatek.c
> +++ b/drivers/pwm/pwm-mediatek.c
> @@ -55,7 +55,6 @@ enum {
> };
>
> struct mtk_pwm_platform_data {
> - unsigned int num_pwms;
> bool pwm45_fixup;
> bool has_clks;
> };
> @@ -226,10 +225,11 @@ static void mtk_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
>
> static int mtk_pwm_probe(struct platform_device *pdev)
> {
> + struct device_node *np = pdev->dev.of_node;
> const struct mtk_pwm_platform_data *data;
> struct mtk_pwm_chip *pc;
> struct resource *res;
> - unsigned int i;
> + unsigned int i, num_pwms;
> int ret;
>
> pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL);
> @@ -246,7 +246,13 @@ static int mtk_pwm_probe(struct platform_device *pdev)
> if (IS_ERR(pc->regs))
> return PTR_ERR(pc->regs);
>
> - for (i = 0; i < data->num_pwms + 2 && pc->soc->has_clks; i++) {
> + ret = of_property_read_u32(np, "mediatek,num-pwms", &num_pwms);
> + if (ret < 0) {
> + dev_err(&pdev->dev, "failed to get pwm number: %d\n", ret);

This sounds wrong. "Failed to get number of pwms" sounds better to my
(non-native) ear.

> + return ret;
> + }
> +
> + for (i = 0; i < num_pwms + 2 && pc->soc->has_clks; i++) {
> pc->clks[i] = devm_clk_get(&pdev->dev, mtk_pwm_clk_name[i]);
> if (IS_ERR(pc->clks[i])) {
> dev_err(&pdev->dev, "clock: %s fail: %ld\n",
> @@ -260,7 +266,7 @@ static int mtk_pwm_probe(struct platform_device *pdev)
> pc->chip.dev = &pdev->dev;
> pc->chip.ops = &mtk_pwm_ops;
> pc->chip.base = -1;
> - pc->chip.npwm = data->num_pwms;
> + pc->chip.npwm = num_pwms;
>
> ret = pwmchip_add(&pc->chip);
> if (ret < 0) {
> @@ -279,32 +285,23 @@ static int mtk_pwm_remove(struct platform_device *pdev)
> }
>
> static const struct mtk_pwm_platform_data mt2712_pwm_data = {
> - .num_pwms = 8,
> - .pwm45_fixup = false,
> - .has_clks = true,
> -};
> -
> -static const struct mtk_pwm_platform_data mt7622_pwm_data = {
> - .num_pwms = 6,
> .pwm45_fixup = false,
> .has_clks = true,

I agree with Matthias Brugger that at least for some time you should be
able to fall back to the right number of pwms if the device tree doesn't
have a num-pwms property.

Best regards
Uwe

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