[PATCH v10 04/12] pwm: mediatek: allocate the clks array dynamically

From: Sam Shih
Date: Wed Sep 25 2019 - 10:34:21 EST


Instead of using fixed size of arrays, allocate the memory for them
based on the information we get from the DT.

Also remove the check for num_pwms, due to dynamically allocate pwm
should not cause array index out of bound.

Signed-off-by: Ryder Lee <ryder.lee@xxxxxxxxxxxx>
Signed-off-by: Sam Shih <sam.shih@xxxxxxxxxxxx>
Reviewed-by: Uwe Kleine-KÃnig <u.kleine-koenig@xxxxxxxxxxxxxx>
---
Changes since v10:
- Remove unuse clk_freq description

Changes since v8:
- Fix warning and build-error

Changes since v6:
- Add a Reviewed-by tag

Changes since v5:
- Follow reviewers's comments
Make the changes of allocate the clks array dynamically as a single patch

Changes since v4:
- Follow reviewers's comments
1. use pc->soc->has_clks to check clocks exist or not.
2. Add error message when probe() unable to get clks
- Fixes bug when SoC is old mips which has no complex clock tree.
if clocks not exist, use the new property from DT to apply period caculation;
otherwise, use clk_get_rate to get clock frequency and apply period caculation.

---
drivers/pwm/pwm-mediatek.c | 84 +++++++++++++++++++-------------------
1 file changed, 41 insertions(+), 43 deletions(-)

diff --git a/drivers/pwm/pwm-mediatek.c b/drivers/pwm/pwm-mediatek.c
index 07e843aeddb1..dcc85d07156f 100644
--- a/drivers/pwm/pwm-mediatek.c
+++ b/drivers/pwm/pwm-mediatek.c
@@ -35,25 +35,6 @@

#define PWM_CLK_DIV_MAX 7

-enum {
- MTK_CLK_MAIN = 0,
- MTK_CLK_TOP,
- MTK_CLK_PWM1,
- MTK_CLK_PWM2,
- MTK_CLK_PWM3,
- MTK_CLK_PWM4,
- MTK_CLK_PWM5,
- MTK_CLK_PWM6,
- MTK_CLK_PWM7,
- MTK_CLK_PWM8,
- MTK_CLK_MAX,
-};
-
-static const char * const mtk_pwm_clk_name[MTK_CLK_MAX] = {
- "main", "top", "pwm1", "pwm2", "pwm3", "pwm4", "pwm5", "pwm6", "pwm7",
- "pwm8"
-};
-
struct mtk_pwm_platform_data {
unsigned int fallback_npwms;
bool pwm45_fixup;
@@ -63,12 +44,16 @@ struct mtk_pwm_platform_data {
* struct mtk_pwm_chip - struct representing PWM chip
* @chip: linux PWM chip representation
* @regs: base address of PWM chip
- * @clks: list of clocks
+ * @clk_top: the top clock generator
+ * @clk_main: the clock used by PWM core
+ * @clk_pwms: the clock used by each PWM channel
*/
struct mtk_pwm_chip {
struct pwm_chip chip;
void __iomem *regs;
- struct clk *clks[MTK_CLK_MAX];
+ struct clk *clk_top;
+ struct clk *clk_main;
+ struct clk **clk_pwms;
const struct mtk_pwm_platform_data *soc;
};

@@ -86,24 +71,24 @@ static int mtk_pwm_clk_enable(struct pwm_chip *chip, struct pwm_device *pwm)
struct mtk_pwm_chip *pc = to_mtk_pwm_chip(chip);
int ret;

- ret = clk_prepare_enable(pc->clks[MTK_CLK_TOP]);
+ ret = clk_prepare_enable(pc->clk_top);
if (ret < 0)
return ret;

- ret = clk_prepare_enable(pc->clks[MTK_CLK_MAIN]);
+ ret = clk_prepare_enable(pc->clk_main);
if (ret < 0)
goto disable_clk_top;

- ret = clk_prepare_enable(pc->clks[MTK_CLK_PWM1 + pwm->hwpwm]);
+ ret = clk_prepare_enable(pc->clk_pwms[pwm->hwpwm]);
if (ret < 0)
goto disable_clk_main;

return 0;

disable_clk_main:
- clk_disable_unprepare(pc->clks[MTK_CLK_MAIN]);
+ clk_disable_unprepare(pc->clk_main);
disable_clk_top:
- clk_disable_unprepare(pc->clks[MTK_CLK_TOP]);
+ clk_disable_unprepare(pc->clk_top);

return ret;
}
@@ -112,9 +97,9 @@ static void mtk_pwm_clk_disable(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct mtk_pwm_chip *pc = to_mtk_pwm_chip(chip);

- clk_disable_unprepare(pc->clks[MTK_CLK_PWM1 + pwm->hwpwm]);
- clk_disable_unprepare(pc->clks[MTK_CLK_MAIN]);
- clk_disable_unprepare(pc->clks[MTK_CLK_TOP]);
+ clk_disable_unprepare(pc->clk_pwms[pwm->hwpwm]);
+ clk_disable_unprepare(pc->clk_main);
+ clk_disable_unprepare(pc->clk_top);
}

static inline u32 mtk_pwm_readl(struct mtk_pwm_chip *chip, unsigned int num,
@@ -134,7 +119,7 @@ static int mtk_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
int duty_ns, int period_ns)
{
struct mtk_pwm_chip *pc = to_mtk_pwm_chip(chip);
- struct clk *clk = pc->clks[MTK_CLK_PWM1 + pwm->hwpwm];
+ struct clk *clk = pc->clk_pwms[pwm->hwpwm];
u32 clkdiv = 0, cnt_period, cnt_duty, reg_width = PWMDWIDTH,
reg_thres = PWMTHRES;
u64 resolution;
@@ -222,8 +207,9 @@ static int mtk_pwm_probe(struct platform_device *pdev)
struct device_node *np = pdev->dev.of_node;
struct mtk_pwm_chip *pc;
struct resource *res;
- unsigned int i, npwms;
+ unsigned int npwms;
int ret;
+ int i;

pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL);
if (!pc)
@@ -248,21 +234,33 @@ static int mtk_pwm_probe(struct platform_device *pdev)
}
}

- /* MAIN + TOP + NPWM < MTK_CLK_MAX */
- if ((npwms + 2) > MTK_CLK_MAX) {
- dev_warn(&pdev->dev, "number of PWMs is larger than %d\n",
- MTK_CLK_MAX - 2);
- npwms = MTK_CLK_MAX - 2;
+ pc->clk_pwms = devm_kcalloc(&pdev->dev, npwms,
+ sizeof(*pc->clk_pwms), GFP_KERNEL);
+ if (!pc->clk_pwms)
+ return -ENOMEM;
+
+ pc->clk_top = devm_clk_get(&pdev->dev, "top");
+ if (IS_ERR(pc->clk_top)) {
+ dev_err(&pdev->dev, "clock: top fail: %ld\n",
+ PTR_ERR(pc->clk_top));
+ return PTR_ERR(pc->clk_top);
+ }
+
+ pc->clk_main = devm_clk_get(&pdev->dev, "main");
+ if (IS_ERR(pc->clk_main)) {
+ dev_err(&pdev->dev, "clock: main fail: %ld\n",
+ PTR_ERR(pc->clk_main));
+ return PTR_ERR(pc->clk_main);
}
+ for (i = 0; i < npwms; i++) {
+ char name[8];

- for (i = 0; i < npwms + 2 ; i++) {
- pc->clks[i] = devm_clk_get(&pdev->dev,
- mtk_pwm_clk_name[i]);
- if (IS_ERR(pc->clks[i])) {
+ snprintf(name, sizeof(name), "pwm%d", i + 1);
+ pc->clk_pwms[i] = devm_clk_get(&pdev->dev, name);
+ if (IS_ERR(pc->clk_pwms[i])) {
dev_err(&pdev->dev, "clock: %s fail: %ld\n",
- mtk_pwm_clk_name[i],
- PTR_ERR(pc->clks[i]));
- return PTR_ERR(pc->clks[i]);
+ name, PTR_ERR(pc->clk_pwms[i]));
+ return PTR_ERR(pc->clk_pwms[i]);
}
}

--
2.17.1