[PATCH 2/3] pwm: imx27: Add 32k clock for pwm in i.MX8QXP MIPI subsystem

[Frank Li <Frank.Li@xxxxxxx>]

From: Liu Ying <victor.liu@xxxxxxx>

PWM in i.MX8QXP MIPI subsystem needs the clock '32k'. Use it if the DTS
provides that.

Signed-off-by: Liu Ying <victor.liu@xxxxxxx>
Signed-off-by: Frank Li <Frank.Li@xxxxxxx>
---
 drivers/pwm/pwm-imx27.c | 33 ++++++++++++++++++++++++++++-----
 1 file changed, 28 insertions(+), 5 deletions(-)

diff --git a/drivers/pwm/pwm-imx27.c b/drivers/pwm/pwm-imx27.c
index 9e2bbf5b4a8ce..032bce7d1fdd3 100644
--- a/drivers/pwm/pwm-imx27.c
+++ b/drivers/pwm/pwm-imx27.c
@@ -15,6 +15,7 @@
 #include <linux/delay.h>
 #include <linux/err.h>
 #include <linux/io.h>
+#include <linux/iopoll.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/of.h>
@@ -82,6 +83,7 @@
 struct pwm_imx27_chip {
 	struct clk	*clk_ipg;
 	struct clk	*clk_per;
+	struct clk	*clk_32k;
 	void __iomem	*mmio_base;
 
 	/*
@@ -101,23 +103,36 @@ static int pwm_imx27_clk_prepare_enable(struct pwm_imx27_chip *imx)
 {
 	int ret;
 
+	if (imx->clk_32k) {
+		ret = clk_prepare_enable(imx->clk_32k);
+		if (ret)
+			goto err1;
+	}
+
 	ret = clk_prepare_enable(imx->clk_ipg);
 	if (ret)
-		return ret;
+		goto err2;
 
 	ret = clk_prepare_enable(imx->clk_per);
-	if (ret) {
-		clk_disable_unprepare(imx->clk_ipg);
-		return ret;
-	}
+	if (ret)
+		goto err3;
 
 	return 0;
+err3:
+	clk_disable_unprepare(imx->clk_ipg);
+err2:
+	if (imx->clk_32k)
+		clk_disable_unprepare(imx->clk_32k);
+err1:
+	return ret;
 }
 
 static void pwm_imx27_clk_disable_unprepare(struct pwm_imx27_chip *imx)
 {
 	clk_disable_unprepare(imx->clk_per);
 	clk_disable_unprepare(imx->clk_ipg);
+	if (imx->clk_32k)
+		clk_disable_unprepare(imx->clk_32k);
 }
 
 static int pwm_imx27_get_state(struct pwm_chip *chip,
@@ -223,6 +238,7 @@ static int pwm_imx27_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 	struct pwm_imx27_chip *imx = to_pwm_imx27_chip(chip);
 	unsigned long long c;
 	unsigned long long clkrate;
+	int val;
 	int ret;
 	u32 cr;
 
@@ -325,6 +341,13 @@ static int pwm_imx27_probe(struct platform_device *pdev)
 		return dev_err_probe(&pdev->dev, PTR_ERR(imx->clk_per),
 				     "failed to get peripheral clock\n");
 
+	imx->clk_32k = devm_clk_get_optional(&pdev->dev, "32k");
+	if (IS_ERR(imx->clk_32k)) {
+		dev_err(&pdev->dev, "getting 32k clock failed with %ld\n",
+				PTR_ERR(imx->clk_32k));
+		return PTR_ERR(imx->clk_32k);
+	}
+
 	chip->ops = &pwm_imx27_ops;
 
 	imx->mmio_base = devm_platform_ioremap_resource(pdev, 0);

-- 
2.34.1