1 files changed, 75 insertions, 85 deletions

diff --git a/drivers/pwm/pwm-lpc32xx.c b/drivers/pwm/pwm-lpc32xx.c
index efb6c7bf8750..c748537e57d1 100644
--- a/drivers/pwm/pwm-lpc32xx.c
+++ b/drivers/pwm/pwm-lpc32xx.c
@@ -1,10 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright 2012 Alexandre Pereira da Silva <aletes.xgr@gmail.com>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; version 2.
- *
  */
 
 #include <linux/clk.h>
@@ -19,17 +15,17 @@
 #include <linux/slab.h>
 
 struct lpc32xx_pwm_chip {
-	struct pwm_chip chip;
 	struct clk *clk;
 	void __iomem *base;
 };
 
-#define PWM_ENABLE	(1 << 31)
-#define PWM_RELOADV(x)	(((x) & 0xFF) << 8)
-#define PWM_DUTY(x)	((x) & 0xFF)
+#define PWM_ENABLE	BIT(31)
+#define PWM_PIN_LEVEL	BIT(30)
 
-#define to_lpc32xx_pwm_chip(_chip) \
-	container_of(_chip, struct lpc32xx_pwm_chip, chip)
+static inline struct lpc32xx_pwm_chip *to_lpc32xx_pwm_chip(struct pwm_chip *chip)
+{
+	return pwmchip_get_drvdata(chip);
+}
 
 static int lpc32xx_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 			      int duty_ns, int period_ns)
@@ -38,41 +34,28 @@ static int lpc32xx_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 	unsigned long long c;
 	int period_cycles, duty_cycles;
 	u32 val;
-
-	c = clk_get_rate(lpc32xx->clk) / 256;
-	c = c * period_ns;
-	do_div(c, NSEC_PER_SEC);
-
-	/* Handle high and low extremes */
-	if (c == 0)
-		c = 1;
-	if (c > 255)
-		c = 0; /* 0 set division by 256 */
-	period_cycles = c;
-
-	/* The duty-cycle value is as follows:
-	 *
-	 *  DUTY-CYCLE     HIGH LEVEL
-	 *      1            99.9%
-	 *      25           90.0%
-	 *      128          50.0%
-	 *      220          10.0%
-	 *      255           0.1%
-	 *      0             0.0%
-	 *
-	 * In other words, the register value is duty-cycle % 256 with
-	 * duty-cycle in the range 1-256.
-	 */
-	c = 256 * duty_ns;
-	do_div(c, period_ns);
-	if (c > 255)
-		c = 255;
-	duty_cycles = 256 - c;
-
-	val = readl(lpc32xx->base + (pwm->hwpwm << 2));
+	c = clk_get_rate(lpc32xx->clk);
+
+	/* The highest acceptable divisor is 256, which is represented by 0 */
+	period_cycles = div64_u64(c * period_ns,
+			       (unsigned long long)NSEC_PER_SEC * 256);
+	if (!period_cycles || period_cycles > 256)
+		return -ERANGE;
+	if (period_cycles == 256)
+		period_cycles = 0;
+
+	/* Compute 256 x #duty/period value and care for corner cases */
+	duty_cycles = div64_u64((unsigned long long)(period_ns - duty_ns) * 256,
+				period_ns);
+	if (!duty_cycles)
+		duty_cycles = 1;
+	if (duty_cycles > 255)
+		duty_cycles = 255;
+
+	val = readl(lpc32xx->base);
 	val &= ~0xFFFF;
-	val |= PWM_RELOADV(period_cycles) | PWM_DUTY(duty_cycles);
-	writel(val, lpc32xx->base + (pwm->hwpwm << 2));
+	val |= (period_cycles << 8) | duty_cycles;
+	writel(val, lpc32xx->base);
 
 	return 0;
 }
@@ -83,13 +66,13 @@ static int lpc32xx_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 	u32 val;
 	int ret;
 
-	ret = clk_enable(lpc32xx->clk);
+	ret = clk_prepare_enable(lpc32xx->clk);
 	if (ret)
 		return ret;
 
-	val = readl(lpc32xx->base + (pwm->hwpwm << 2));
+	val = readl(lpc32xx->base);
 	val |= PWM_ENABLE;
-	writel(val, lpc32xx->base + (pwm->hwpwm << 2));
+	writel(val, lpc32xx->base);
 
 	return 0;
 }
@@ -99,35 +82,55 @@ static void lpc32xx_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
 	struct lpc32xx_pwm_chip *lpc32xx = to_lpc32xx_pwm_chip(chip);
 	u32 val;
 
-	val = readl(lpc32xx->base + (pwm->hwpwm << 2));
+	val = readl(lpc32xx->base);
 	val &= ~PWM_ENABLE;
-	writel(val, lpc32xx->base + (pwm->hwpwm << 2));
+	writel(val, lpc32xx->base);
+
+	clk_disable_unprepare(lpc32xx->clk);
+}
+
+static int lpc32xx_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+			     const struct pwm_state *state)
+{
+	int err;
+
+	if (state->polarity != PWM_POLARITY_NORMAL)
+		return -EINVAL;
+
+	if (!state->enabled) {
+		if (pwm->state.enabled)
+			lpc32xx_pwm_disable(chip, pwm);
+
+		return 0;
+	}
 
-	clk_disable(lpc32xx->clk);
+	err = lpc32xx_pwm_config(chip, pwm, state->duty_cycle, state->period);
+	if (err)
+		return err;
+
+	if (!pwm->state.enabled)
+		err = lpc32xx_pwm_enable(chip, pwm);
+
+	return err;
 }
 
 static const struct pwm_ops lpc32xx_pwm_ops = {
-	.config = lpc32xx_pwm_config,
-	.enable = lpc32xx_pwm_enable,
-	.disable = lpc32xx_pwm_disable,
-	.owner = THIS_MODULE,
+	.apply = lpc32xx_pwm_apply,
 };
 
 static int lpc32xx_pwm_probe(struct platform_device *pdev)
 {
+	struct pwm_chip *chip;
 	struct lpc32xx_pwm_chip *lpc32xx;
-	struct resource *res;
 	int ret;
+	u32 val;
 
-	lpc32xx = devm_kzalloc(&pdev->dev, sizeof(*lpc32xx), GFP_KERNEL);
-	if (!lpc32xx)
-		return -ENOMEM;
-
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	if (!res)
-		return -EINVAL;
+	chip = devm_pwmchip_alloc(&pdev->dev, 1, sizeof(*lpc32xx));
+	if (IS_ERR(chip))
+		return PTR_ERR(chip);
+	lpc32xx = to_lpc32xx_pwm_chip(chip);
 
-	lpc32xx->base = devm_ioremap_resource(&pdev->dev, res);
+	lpc32xx->base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(lpc32xx->base))
 		return PTR_ERR(lpc32xx->base);
 
@@ -135,33 +138,22 @@ static int lpc32xx_pwm_probe(struct platform_device *pdev)
 	if (IS_ERR(lpc32xx->clk))
 		return PTR_ERR(lpc32xx->clk);
 
-	lpc32xx->chip.dev = &pdev->dev;
-	lpc32xx->chip.ops = &lpc32xx_pwm_ops;
-	lpc32xx->chip.npwm = 2;
-	lpc32xx->chip.base = -1;
+	chip->ops = &lpc32xx_pwm_ops;
+
+	/* If PWM is disabled, configure the output to the default value */
+	val = readl(lpc32xx->base);
+	val &= ~PWM_PIN_LEVEL;
+	writel(val, lpc32xx->base);
 
-	ret = pwmchip_add(&lpc32xx->chip);
+	ret = devm_pwmchip_add(&pdev->dev, chip);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "failed to add PWM chip, error %d\n", ret);
 		return ret;
 	}
 
-	platform_set_drvdata(pdev, lpc32xx);
-
 	return 0;
 }
 
-static int lpc32xx_pwm_remove(struct platform_device *pdev)
-{
-	struct lpc32xx_pwm_chip *lpc32xx = platform_get_drvdata(pdev);
-	unsigned int i;
-
-	for (i = 0; i < lpc32xx->chip.npwm; i++)
-		pwm_disable(&lpc32xx->chip.pwms[i]);
-
-	return pwmchip_remove(&lpc32xx->chip);
-}
-
 static const struct of_device_id lpc32xx_pwm_dt_ids[] = {
 	{ .compatible = "nxp,lpc3220-pwm", },
 	{ /* sentinel */ }
@@ -171,11 +163,9 @@ MODULE_DEVICE_TABLE(of, lpc32xx_pwm_dt_ids);
 static struct platform_driver lpc32xx_pwm_driver = {
 	.driver = {
 		.name = "lpc32xx-pwm",
-		.owner = THIS_MODULE,
-		.of_match_table = of_match_ptr(lpc32xx_pwm_dt_ids),
+		.of_match_table = lpc32xx_pwm_dt_ids,
 	},
 	.probe = lpc32xx_pwm_probe,
-	.remove = lpc32xx_pwm_remove,
 };
 module_platform_driver(lpc32xx_pwm_driver);