pwm: imx: Add polarity inversion support to i.MX's PWMv2

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@toradex.com>
Signed-off-by: Lukasz Majewski <l.majewski@majess.pl>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

1 files changed, 19 insertions, 5 deletions

diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c
index 0a81c028cb11..957099e82ed3 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)
@@ -163,6 +164,7 @@ 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);
 
@@ -207,11 +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 if (cstate.enabled) {
                 writel(0, imx->mmio_base + MX3_PWMCR);
 
@@ -234,6 +240,7 @@ static const struct pwm_ops imx_pwm_ops_v2 = {
 };
 
 struct imx_pwm_data {
+        bool polarity_supported;
         const struct pwm_ops *ops;
 };
 
@@ -242,6 +249,7 @@ static struct imx_pwm_data imx_pwm_data_v1 = {
 };
 
 static struct imx_pwm_data imx_pwm_data_v2 = {
+        .polarity_supported = true,
         .ops = &imx_pwm_ops_v2,
 };
 
@@ -283,6 +291,12 @@ static int imx_pwm_probe(struct platform_device *pdev)
         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);
         if (IS_ERR(imx->mmio_base))