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@xxxxxxxxxxxx>
---
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) {
