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Subject[PATCH v3 1/7] pwm: rockchip: Add APB and function both clocks support
Date
New PWM module provides two individual clocks for APB clock
and function clock.

Signed-off-by: David Wu <david.wu@rock-chips.com>
Acked-by: Rob Herring <robh@kernel.org>
---
changes in v3:
- clk_get with NULL argument again if it was error, when clk_get with "pwm" argument.
- To get clk count, use of_count_phandle_with_args instead of of_property_count_strings.

.../devicetree/bindings/pwm/pwm-rockchip.txt | 8 ++-
drivers/pwm/pwm-rockchip.c | 58 ++++++++++++++++++----
2 files changed, 56 insertions(+), 10 deletions(-)

diff --git a/Documentation/devicetree/bindings/pwm/pwm-rockchip.txt b/Documentation/devicetree/bindings/pwm/pwm-rockchip.txt
index b8be3d0..2350ef9 100644
--- a/Documentation/devicetree/bindings/pwm/pwm-rockchip.txt
+++ b/Documentation/devicetree/bindings/pwm/pwm-rockchip.txt
@@ -6,7 +6,13 @@ Required properties:
"rockchip,rk3288-pwm": found on RK3288 SoC
"rockchip,vop-pwm": found integrated in VOP on RK3288 SoC
- reg: physical base address and length of the controller's registers
- - clocks: phandle and clock specifier of the PWM reference clock
+ - clocks: See ../clock/clock-bindings.txt
+ - For older hardware (rk2928, rk3066, rk3188, rk3228, rk3288, rk3399):
+ - There is one clock that's used both to derive the functional clock
+ for the device and as the bus clock.
+ - For newer hardware (rk3328 and future socs): specified by name
+ - "pwm": This is used to derive the functional clock.
+ - "pclk": This is the APB bus clock.
- #pwm-cells: must be 2 (rk2928) or 3 (rk3288). See pwm.txt in this directory
for a description of the cell format.

diff --git a/drivers/pwm/pwm-rockchip.c b/drivers/pwm/pwm-rockchip.c
index 744d561..ac3cd5e 100644
--- a/drivers/pwm/pwm-rockchip.c
+++ b/drivers/pwm/pwm-rockchip.c
@@ -33,6 +33,7 @@
struct rockchip_pwm_chip {
struct pwm_chip chip;
struct clk *clk;
+ struct clk *pclk;
const struct rockchip_pwm_data *data;
void __iomem *base;
};
@@ -145,7 +146,7 @@ static void rockchip_pwm_get_state(struct pwm_chip *chip,
u64 tmp;
int ret;

- ret = clk_enable(pc->clk);
+ ret = clk_enable(pc->pclk);
if (ret)
return;

@@ -161,7 +162,7 @@ static void rockchip_pwm_get_state(struct pwm_chip *chip,

pc->data->get_state(chip, pwm, state);

- clk_disable(pc->clk);
+ clk_disable(pc->pclk);
}

static int rockchip_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
@@ -224,7 +225,7 @@ static int rockchip_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
pwm_get_state(pwm, &curstate);
enabled = curstate.enabled;

- ret = clk_enable(pc->clk);
+ ret = clk_enable(pc->pclk);
if (ret)
return ret;

@@ -257,7 +258,7 @@ static int rockchip_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
rockchip_pwm_get_state(chip, pwm, state);

out:
- clk_disable(pc->clk);
+ clk_disable(pc->pclk);

return ret;
}
@@ -328,7 +329,7 @@ static int rockchip_pwm_probe(struct platform_device *pdev)
const struct of_device_id *id;
struct rockchip_pwm_chip *pc;
struct resource *r;
- int ret;
+ int ret, count;

id = of_match_device(rockchip_pwm_dt_ids, &pdev->dev);
if (!id)
@@ -343,13 +344,43 @@ static int rockchip_pwm_probe(struct platform_device *pdev)
if (IS_ERR(pc->base))
return PTR_ERR(pc->base);

- pc->clk = devm_clk_get(&pdev->dev, NULL);
- if (IS_ERR(pc->clk))
- return PTR_ERR(pc->clk);
+ pc->clk = devm_clk_get(&pdev->dev, "pwm");
+ if (IS_ERR(pc->clk)) {
+ pc->clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(pc->clk)) {
+ ret = PTR_ERR(pc->clk);
+ if (ret != -EPROBE_DEFER)
+ dev_err(&pdev->dev, "Can't get bus clk: %d\n",
+ ret);
+ return ret;
+ }
+ }
+
+ count = of_count_phandle_with_args(pdev->dev.of_node,
+ "clocks", "#clock-cells");
+ if (count == 2)
+ pc->pclk = devm_clk_get(&pdev->dev, "pclk");
+ else
+ pc->pclk = pc->clk;
+
+ if (IS_ERR(pc->pclk)) {
+ ret = PTR_ERR(pc->pclk);
+ if (ret != -EPROBE_DEFER)
+ dev_err(&pdev->dev, "Can't get APB clk: %d\n", ret);
+ return ret;
+ }

ret = clk_prepare_enable(pc->clk);
- if (ret)
+ if (ret) {
+ dev_err(&pdev->dev, "Can't prepare enable bus clk: %d\n", ret);
return ret;
+ }
+
+ ret = clk_prepare(pc->pclk);
+ if (ret) {
+ dev_err(&pdev->dev, "Can't prepare APB clk: %d\n", ret);
+ goto err_clk;
+ }

platform_set_drvdata(pdev, pc);

@@ -368,12 +399,20 @@ static int rockchip_pwm_probe(struct platform_device *pdev)
if (ret < 0) {
clk_unprepare(pc->clk);
dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
+ goto err_pclk;
}

/* Keep the PWM clk enabled if the PWM appears to be up and running. */
if (!pwm_is_enabled(pc->chip.pwms))
clk_disable(pc->clk);

+ return 0;
+
+err_pclk:
+ clk_unprepare(pc->pclk);
+err_clk:
+ clk_disable_unprepare(pc->clk);
+
return ret;
}

@@ -395,6 +434,7 @@ static int rockchip_pwm_remove(struct platform_device *pdev)
if (pwm_is_enabled(pc->chip.pwms))
clk_disable(pc->clk);

+ clk_unprepare(pc->pclk);
clk_unprepare(pc->clk);

return pwmchip_remove(&pc->chip);
--
1.9.1

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