lkml.org 
[lkml]   [2019]   [Jan]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: [PATCH v1 1/5] pwm: mediatek: add a property "mediatek,num-pwms"
    From
    Date


    On 18/01/2019 04:24, Ryder Lee wrote:
    > This adds a property "mediatek,num-pwms" to avoid having an endless
    > list of compatibles with no differences for the same driver.
    >
    > Thus, the driver should have backwards compatibility to older DTs.
    >
    > Signed-off-by: Ryder Lee <ryder.lee@mediatek.com>
    > ---
    > Changes since v1: add some checks for backwards compatibility.
    > ---
    > drivers/pwm/pwm-mediatek.c | 27 ++++++++++++++++++---------
    > 1 file changed, 18 insertions(+), 9 deletions(-)
    >
    > diff --git a/drivers/pwm/pwm-mediatek.c b/drivers/pwm/pwm-mediatek.c
    > index eb6674c..81b7e5e 100644
    > --- a/drivers/pwm/pwm-mediatek.c
    > +++ b/drivers/pwm/pwm-mediatek.c
    > @@ -55,7 +55,7 @@ enum {
    > };
    >
    > struct mtk_pwm_platform_data {
    > - unsigned int num_pwms;
    > + unsigned int num_pwms; /* it should not be used in the future SoCs */
    > bool pwm45_fixup;
    > bool has_clks;
    > };
    > @@ -226,27 +226,36 @@ static void mtk_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
    >
    > static int mtk_pwm_probe(struct platform_device *pdev)
    > {
    > - const struct mtk_pwm_platform_data *data;
    > + struct device_node *np = pdev->dev.of_node;
    > 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);
    > if (!pc)
    > return -ENOMEM;
    >
    > - data = of_device_get_match_data(&pdev->dev);
    > - if (data == NULL)
    > - return -EINVAL;
    > - pc->soc = data;
    > + pc->soc = of_device_get_match_data(&pdev->dev);
    >
    > res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    > pc->regs = devm_ioremap_resource(&pdev->dev, res);
    > if (IS_ERR(pc->regs))
    > return PTR_ERR(pc->regs);
    >
    > - for (i = 0; i < data->num_pwms + 2 && pc->soc->has_clks; i++) {
    > + /* Check if we have set 'num-pwms' in DTs. */
    > + ret = of_property_read_u32(np, "mediatek,num-pwms", &num_pwms);
    > + if (ret < 0) {
    > + /* If no, fallback to use SoC data for backwards compatibility. */
    > + if (pc->soc->num_pwms) {
    > + num_pwms = pc->soc->num_pwms;

    Maybe that's bike shedding, but I think it would be better to carve out the
    num_pwms from the mtk_pwm_platform_data and check against the compatible here.
    With a expressive comment it will help other driver developers to not start
    adding num_pwms in the platform data in their first attempt.

    Regards,
    Matthias

    > + } else {
    > + dev_err(&pdev->dev, "failed to get pwm number: %d\n", ret);
    > + 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 +269,7 @@ 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) {
    >

    \
     
     \ /
      Last update: 2019-01-18 09:44    [W:3.289 / U:0.532 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site