[PATCH v2 8/10] pwm: mediatek: add new property and fix mt7628 pwm

From: Sam Shih
Date: Wed Aug 14 2019 - 06:45:15 EST


From: sam shih <sam.shih@xxxxxxxxxxxx>

This fix mt7628 pwm during configure from userspace. The SoC
is legacy MIPS and has no complex clock tree. This patch add property
clock-frequency to the SoC specific data and legacy MIPS SoC need to
configure it in DT. This property is use for period calculation.

Signed-off-by: Sam Shih <sam.shih@xxxxxxxxxxxx>
---
drivers/pwm/pwm-mediatek.c | 15 ++++++++++++++-
1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/pwm/pwm-mediatek.c b/drivers/pwm/pwm-mediatek.c
index d696df7a58fa..922a7543a2b1 100644
--- a/drivers/pwm/pwm-mediatek.c
+++ b/drivers/pwm/pwm-mediatek.c
@@ -53,6 +53,7 @@ struct pwm_mediatek_chip {
struct clk *clk_top;
struct clk *clk_main;
struct clk **clk_pwms;
+ unsigned int clock_frequency;
const struct pwm_mediatek_of_data *soc;
};

@@ -139,7 +140,10 @@ static int pwm_mediatek_config(struct pwm_chip *chip, struct pwm_device *pwm,

/* Using resolution in picosecond gets accuracy higher */
resolution = (u64)NSEC_PER_SEC * 1000;
- do_div(resolution, clk_get_rate(clk));
+ if (pc->soc->has_clks)
+ do_div(resolution, clk_get_rate(clk));
+ else
+ do_div(resolution, pc->clock_frequency);

cnt_period = DIV_ROUND_CLOSEST_ULL((u64)period_ns * 1000, resolution);
while (cnt_period > 8191) {
@@ -216,6 +220,7 @@ static int pwm_mediatek_probe(struct platform_device *pdev)
struct pwm_mediatek_chip *pc;
struct resource *res;
unsigned int npwms;
+ unsigned int clock_frequency;
int ret;

pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL);
@@ -265,6 +270,14 @@ static int pwm_mediatek_probe(struct platform_device *pdev)
if (IS_ERR(pc->clk_pwms[i]))
return PTR_ERR(pc->clk_pwms[i]);
}
+ } else {
+ ret = of_property_read_u32(np, "clock-frequency",
+ &clock_frequency);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "failed to get clock_frequency\n");
+ return ret;
+ }
+ pc->clock_frequency = clock_frequency;
}

platform_set_drvdata(pdev, pc);
--
2.17.1