[PATCH v4 11/11] pwm: imx: Add polarity inversion support to i.MX's PWMv2

From: Lukasz Majewski
Date: Wed Jan 04 2017 - 18:38:01 EST


With this patch the polarity settings for i.MX's PWMv2 is now supported
on top of atomic PWM setting

Signed-off-by: Bhuvanchandra DV <bhuvanchandra.dv@xxxxxxxxxxx>
Signed-off-by: Lukasz Majewski <l.majewski@xxxxxxxxx>
---
Changes for v4:
- MX3_PWMCR_POUTC setting adjustements after apply_v2() previous changes

Changes for v3:
- None

Changes for v2:
- New patch
---
drivers/pwm/pwm-imx.c | 22 +++++++++++++++++-----
1 file changed, 17 insertions(+), 5 deletions(-)

diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c
index afca5f5..d35d83f 100644
--- a/drivers/pwm/pwm-imx.c
+++ b/drivers/pwm/pwm-imx.c
@@ -38,6 +38,7 @@
#define MX3_PWMCR_DOZEEN (1 << 24)
#define MX3_PWMCR_WAITEN (1 << 23)
#define MX3_PWMCR_DBGEN (1 << 22)
+#define MX3_PWMCR_POUTC (1 << 18)
#define MX3_PWMCR_CLKSRC_IPG_HIGH (2 << 16)
#define MX3_PWMCR_CLKSRC_IPG (1 << 16)
#define MX3_PWMCR_SWR (1 << 3)
@@ -164,6 +165,7 @@ static int imx_pwm_apply_v2(struct pwm_chip *chip, struct pwm_device *pwm,
struct pwm_state cstate;
unsigned long long c;
int ret;
+ u32 cr;

pwm_get_state(pwm, &cstate);

@@ -207,12 +209,15 @@ static int imx_pwm_apply_v2(struct pwm_chip *chip, struct pwm_device *pwm,
writel(duty_cycles, imx->mmio_base + MX3_PWMSAR);
writel(period_cycles, imx->mmio_base + MX3_PWMPR);

- writel(MX3_PWMCR_PRESCALER(prescale) |
- MX3_PWMCR_DOZEEN | MX3_PWMCR_WAITEN |
- MX3_PWMCR_DBGEN | MX3_PWMCR_CLKSRC_IPG_HIGH |
- MX3_PWMCR_EN,
- imx->mmio_base + MX3_PWMCR);
+ cr = MX3_PWMCR_PRESCALER(prescale) |
+ MX3_PWMCR_DOZEEN | MX3_PWMCR_WAITEN |
+ MX3_PWMCR_DBGEN | MX3_PWMCR_CLKSRC_IPG_HIGH |
+ MX3_PWMCR_EN;
+
+ if (state->polarity == PWM_POLARITY_INVERSED)
+ cr |= MX3_PWMCR_POUTC;

+ writel(cr, imx->mmio_base + MX3_PWMCR);
} else {
writel(0, imx->mmio_base + MX3_PWMCR);

@@ -235,6 +240,7 @@ static struct pwm_ops imx_pwm_ops_v2 = {
};

struct imx_pwm_data {
+ bool polarity_supported;
struct pwm_ops *pwm_ops;
};

@@ -243,6 +249,7 @@ static struct imx_pwm_data imx_pwm_data_v1 = {
};

static struct imx_pwm_data imx_pwm_data_v2 = {
+ .polarity_supported = true,
.pwm_ops = &imx_pwm_ops_v2,
};

@@ -283,6 +290,11 @@ static int imx_pwm_probe(struct platform_device *pdev)
imx->chip.base = -1;
imx->chip.npwm = 1;
imx->chip.can_sleep = true;
+ if (data->polarity_supported) {
+ dev_dbg(&pdev->dev, "PWM supports output inversion\n");
+ imx->chip.of_xlate = of_pwm_xlate_with_flags;
+ imx->chip.of_pwm_n_cells = 3;
+ }

r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
imx->mmio_base = devm_ioremap_resource(&pdev->dev, r);
--
2.1.4