linux-kernel - [PATCH v5 11/11] pwm: imx: Add polarity inversion support to i.MX's PWMv2

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Date:   Sun, 29 Jan 2017 22:54:15 +0100
From:   Lukasz Majewski <lukma@...x.de>
To:     Thierry Reding <thierry.reding@...il.com>,
        Sascha Hauer <s.hauer@...gutronix.de>,
        Stefan Agner <stefan@...er.ch>,
        Boris Brezillon <boris.brezillon@...e-electrons.com>,
        linux-pwm@...r.kernel.org,
        Bhuvanchandra DV <bhuvanchandra.dv@...adex.com>,
        linux-kernel@...r.kernel.org
Cc:     Lothar Wassmann <LW@...o-electronics.de>, kernel@...gutronix.de,
        Fabio Estevam <fabio.estevam@....com>,
        Lukasz Majewski <lukma@...x.de>,
        Lukasz Majewski <l.majewski@...ess.pl>
Subject: [PATCH v5 11/11] 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@...adex.com>
Signed-off-by: Lukasz Majewski <l.majewski@...ess.pl>
---
Changes for v5:
- Adjust to corrected ->apply_v2() code

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 e037023..9f7e787 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);
 
@@ -208,12 +210,15 @@ 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);
 
@@ -236,6 +241,7 @@ static struct pwm_ops imx_pwm_ops_v2 = {
 };
 
 struct imx_pwm_data {
+	bool polarity_supported;
 	struct pwm_ops *pwm_ops;
 };
 
@@ -244,6 +250,7 @@ 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,
 };
 
@@ -284,6 +291,11 @@ 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