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Subject[PATCH v3 2/4] pwm: rockchip: Allow polarity invert on rk3288
Date
The rk3288 has the ability to invert the polarity of the PWM.  Let's
enable that ability.

To do this we increase the number of pwm_cells to 3 to allow using the
PWM_POLARITY_INVERTED flag. Since the PWM driver on rk3288 is very
new, I thought this was OK.

Signed-off-by: Doug Anderson <dianders@chromium.org>
---
Changes in v3:
- Don't store a private copy of polarity.
- Use true instead of 1.
- Cleanup init order with "has_invert".

Changes in v2: None

.../devicetree/bindings/pwm/pwm-rockchip.txt | 4 +-
drivers/pwm/pwm-rockchip.c | 48 ++++++++++++++++++----
2 files changed, 43 insertions(+), 9 deletions(-)

diff --git a/Documentation/devicetree/bindings/pwm/pwm-rockchip.txt b/Documentation/devicetree/bindings/pwm/pwm-rockchip.txt
index d47d15a..b8be3d0 100644
--- a/Documentation/devicetree/bindings/pwm/pwm-rockchip.txt
+++ b/Documentation/devicetree/bindings/pwm/pwm-rockchip.txt
@@ -7,8 +7,8 @@ Required properties:
"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
- - #pwm-cells: should be 2. See pwm.txt in this directory for a
- description of the cell format.
+ - #pwm-cells: must be 2 (rk2928) or 3 (rk3288). See pwm.txt in this directory
+ for a description of the cell format.

Example:

diff --git a/drivers/pwm/pwm-rockchip.c b/drivers/pwm/pwm-rockchip.c
index bdd8644..646aed2 100644
--- a/drivers/pwm/pwm-rockchip.c
+++ b/drivers/pwm/pwm-rockchip.c
@@ -24,7 +24,9 @@
#define PWM_ENABLE (1 << 0)
#define PWM_CONTINUOUS (1 << 1)
#define PWM_DUTY_POSITIVE (1 << 3)
+#define PWM_DUTY_NEGATIVE (0 << 3)
#define PWM_INACTIVE_NEGATIVE (0 << 4)
+#define PWM_INACTIVE_POSITIVE (1 << 4)
#define PWM_OUTPUT_LEFT (0 << 5)
#define PWM_LP_DISABLE (0 << 8)

@@ -45,8 +47,10 @@ struct rockchip_pwm_regs {
struct rockchip_pwm_data {
struct rockchip_pwm_regs regs;
unsigned int prescaler;
+ bool has_invert;

- void (*set_enable)(struct pwm_chip *chip, bool enable);
+ void (*set_enable)(struct pwm_chip *chip,
+ struct pwm_device *pwm, bool enable);
};

static inline struct rockchip_pwm_chip *to_rockchip_pwm_chip(struct pwm_chip *c)
@@ -54,7 +58,8 @@ static inline struct rockchip_pwm_chip *to_rockchip_pwm_chip(struct pwm_chip *c)
return container_of(c, struct rockchip_pwm_chip, chip);
}

-static void rockchip_pwm_set_enable_v1(struct pwm_chip *chip, bool enable)
+static void rockchip_pwm_set_enable_v1(struct pwm_chip *chip,
+ struct pwm_device *pwm, bool enable)
{
struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
u32 enable_conf = PWM_CTRL_OUTPUT_EN | PWM_CTRL_TIMER_EN;
@@ -70,14 +75,19 @@ static void rockchip_pwm_set_enable_v1(struct pwm_chip *chip, bool enable)
writel_relaxed(val, pc->base + pc->data->regs.ctrl);
}

-static void rockchip_pwm_set_enable_v2(struct pwm_chip *chip, bool enable)
+static void rockchip_pwm_set_enable_v2(struct pwm_chip *chip,
+ struct pwm_device *pwm, bool enable)
{
struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
u32 enable_conf = PWM_OUTPUT_LEFT | PWM_LP_DISABLE | PWM_ENABLE |
- PWM_CONTINUOUS | PWM_DUTY_POSITIVE |
- PWM_INACTIVE_NEGATIVE;
+ PWM_CONTINUOUS;
u32 val;

+ if (pwm->polarity == PWM_POLARITY_INVERSED)
+ enable_conf |= PWM_DUTY_NEGATIVE | PWM_INACTIVE_POSITIVE;
+ else
+ enable_conf |= PWM_DUTY_POSITIVE | PWM_INACTIVE_NEGATIVE;
+
val = readl_relaxed(pc->base + pc->data->regs.ctrl);

if (enable)
@@ -124,6 +134,23 @@ static int rockchip_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
return 0;
}

+int rockchip_pwm_set_polarity(struct pwm_chip *chip, struct pwm_device *pwm,
+ enum pwm_polarity polarity)
+{
+ struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
+
+ if (!pc->data->has_invert)
+ return -ENOSYS;
+
+ /*
+ * No action needed here because pwm->polarity will be set by the core
+ * and the core will only change polarity when the PWM is not enabled.
+ * We'll handle things in set_enable().
+ */
+
+ return 0;
+}
+
static int rockchip_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
@@ -133,7 +160,7 @@ static int rockchip_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
if (ret)
return ret;

- pc->data->set_enable(chip, true);
+ pc->data->set_enable(chip, pwm, true);

return 0;
}
@@ -142,13 +169,14 @@ static void rockchip_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);

- pc->data->set_enable(chip, false);
+ pc->data->set_enable(chip, pwm, false);

clk_disable(pc->clk);
}

static const struct pwm_ops rockchip_pwm_ops = {
.config = rockchip_pwm_config,
+ .set_polarity = rockchip_pwm_set_polarity,
.enable = rockchip_pwm_enable,
.disable = rockchip_pwm_disable,
.owner = THIS_MODULE,
@@ -173,6 +201,7 @@ static const struct rockchip_pwm_data pwm_data_v2 = {
.ctrl = 0x0c,
},
.prescaler = 1,
+ .has_invert = true,
.set_enable = rockchip_pwm_set_enable_v2,
};

@@ -184,6 +213,7 @@ static const struct rockchip_pwm_data pwm_data_vop = {
.ctrl = 0x00,
},
.prescaler = 1,
+ .has_invert = true,
.set_enable = rockchip_pwm_set_enable_v2,
};

@@ -230,6 +260,10 @@ static int rockchip_pwm_probe(struct platform_device *pdev)
pc->chip.ops = &rockchip_pwm_ops;
pc->chip.base = -1;
pc->chip.npwm = 1;
+ if (pc->data->has_invert) {
+ pc->chip.of_xlate = of_pwm_xlate_with_flags;
+ pc->chip.of_pwm_n_cells = 3;
+ }

ret = pwmchip_add(&pc->chip);
if (ret < 0) {
--
2.1.0.rc2.206.gedb03e5


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