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>

diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c
index 0a81c028cb117d7d52912b639cd2445736295326..957099e82ed3783d0ec1a1fd455570e55c0e20f7 100644 (file)
--- 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))