[PATCH v1 1/5] pwm: mediatek: add a property "mediatek,num-pwms"

Ryder Lee
2019-01-18T03:24:41Z

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-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>
---
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;
+ } 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) {
--
1.9.1