pwm: imx-tpm: Make use of devm_pwmchip_alloc() function

This prepares the pwm-tmp driver to further changes of the pwm core
outlined in the commit introducing devm_pwmchip_alloc(). There is no
intended semantical change and the driver should behave as before.

Link: https://lore.kernel.org/r/5de5d53295fa445d58a79f83421dd3406166c3c6.1707900770.git.u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

drivers/pwm/pwm-imx-tpm.c

@@ -57,7 +57,6 @@
 #define PWM_IMX_TPM_MOD_MOD	GENMASK(PWM_IMX_TPM_MOD_WIDTH - 1, 0)
 
 struct imx_tpm_pwm_chip {
-	struct pwm_chip chip;
 	struct clk *clk;
 	void __iomem *base;
 	struct mutex lock;
@@ -75,7 +74,7 @@ struct imx_tpm_pwm_param {
 static inline struct imx_tpm_pwm_chip *
 to_imx_tpm_pwm_chip(struct pwm_chip *chip)
 {
-	return container_of(chip, struct imx_tpm_pwm_chip, chip);
+	return pwmchip_get_drvdata(chip);
 }
 
 /*
@@ -336,35 +335,40 @@ static const struct pwm_ops imx_tpm_pwm_ops = {
 
 static int pwm_imx_tpm_probe(struct platform_device *pdev)
 {
+	struct pwm_chip *chip;
 	struct imx_tpm_pwm_chip *tpm;
+	void __iomem *base;
 	int ret;
+	unsigned int npwm;
 	u32 val;
 
-	tpm = devm_kzalloc(&pdev->dev, sizeof(*tpm), GFP_KERNEL);
-	if (!tpm)
-		return -ENOMEM;
+	base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	/* get number of channels */
+	val = readl(base + PWM_IMX_TPM_PARAM);
+	npwm = FIELD_GET(PWM_IMX_TPM_PARAM_CHAN, val);
+
+	chip = devm_pwmchip_alloc(&pdev->dev, npwm, sizeof(*tpm));
+	if (IS_ERR(chip))
+		return PTR_ERR(chip);
+	tpm = to_imx_tpm_pwm_chip(chip);
 
 	platform_set_drvdata(pdev, tpm);
 
-	tpm->base = devm_platform_ioremap_resource(pdev, 0);
-	if (IS_ERR(tpm->base))
-		return PTR_ERR(tpm->base);
+	tpm->base = base;
 
 	tpm->clk = devm_clk_get_enabled(&pdev->dev, NULL);
 	if (IS_ERR(tpm->clk))
 		return dev_err_probe(&pdev->dev, PTR_ERR(tpm->clk),
 				     "failed to get PWM clock\n");
 
-	tpm->chip.dev = &pdev->dev;
-	tpm->chip.ops = &imx_tpm_pwm_ops;
-
-	/* get number of channels */
-	val = readl(tpm->base + PWM_IMX_TPM_PARAM);
-	tpm->chip.npwm = FIELD_GET(PWM_IMX_TPM_PARAM_CHAN, val);
+	chip->ops = &imx_tpm_pwm_ops;
 
 	mutex_init(&tpm->lock);
 
-	ret = devm_pwmchip_add(&pdev->dev, &tpm->chip);
+	ret = devm_pwmchip_add(&pdev->dev, chip);
 	if (ret)
 		return dev_err_probe(&pdev->dev, ret, "failed to add PWM chip\n");