2019-09-26 09:37:17

by Sam Shih

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

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 <[email protected]>
Signed-off-by: Sam Shih <[email protected]>
Reviewed-by: Uwe Kleine-König <[email protected]>
---
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