1// SPDX-License-Identifier: GPL-2.0+
  2/*
  3 * Cirrus Logic CLPS711X PWM driver
  4 * Author: Alexander Shiyan <shc_work@mail.ru>
  5 */
  6
  7#include <linux/clk.h>
  8#include <linux/io.h>
  9#include <linux/module.h>
 10#include <linux/of.h>
 11#include <linux/platform_device.h>
 12#include <linux/pwm.h>
 13
 14struct clps711x_chip {
 15	void __iomem *pmpcon;
 16	struct clk *clk;
 17	spinlock_t lock;
 18};
 19
 20static inline struct clps711x_chip *to_clps711x_chip(struct pwm_chip *chip)
 21{
 22	return pwmchip_get_drvdata(chip);
 23}
 24
 25static int clps711x_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
 26{
 27	struct clps711x_chip *priv = to_clps711x_chip(chip);
 28	unsigned int freq = clk_get_rate(priv->clk);
 29
 30	if (!freq)
 31		return -EINVAL;
 32
 33	/* Store constant period value */
 34	pwm->args.period = DIV_ROUND_CLOSEST(NSEC_PER_SEC, freq);
 35
 36	return 0;
 37}
 38
 39static int clps711x_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 40			      const struct pwm_state *state)
 41{
 42	struct clps711x_chip *priv = to_clps711x_chip(chip);
 43	/* PWM0 - bits 4..7, PWM1 - bits 8..11 */
 44	u32 shift = (pwm->hwpwm + 1) * 4;
 45	unsigned long flags;
 46	u32 pmpcon, val;
 47
 48	if (state->polarity != PWM_POLARITY_NORMAL)
 49		return -EINVAL;
 50
 51	if (state->period != pwm->args.period)
 52		return -EINVAL;
 53
 54	if (state->enabled)
 55		val = mul_u64_u64_div_u64(state->duty_cycle, 0xf, state->period);
 56	else
 57		val = 0;
 58
 59	spin_lock_irqsave(&priv->lock, flags);
 60
 61	pmpcon = readl(priv->pmpcon);
 62	pmpcon &= ~(0xf << shift);
 63	pmpcon |= val << shift;
 64	writel(pmpcon, priv->pmpcon);
 65
 66	spin_unlock_irqrestore(&priv->lock, flags);
 67
 68	return 0;
 69}
 70
 71static const struct pwm_ops clps711x_pwm_ops = {
 72	.request = clps711x_pwm_request,
 73	.apply = clps711x_pwm_apply,
 74};
 75
 76static int clps711x_pwm_probe(struct platform_device *pdev)
 77{
 78	struct pwm_chip *chip;
 79	struct clps711x_chip *priv;
 80
 81	chip = devm_pwmchip_alloc(&pdev->dev, 2, sizeof(*priv));
 82	if (IS_ERR(chip))
 83		return PTR_ERR(chip);
 84	priv = to_clps711x_chip(chip);
 85
 86	priv->pmpcon = devm_platform_ioremap_resource(pdev, 0);
 87	if (IS_ERR(priv->pmpcon))
 88		return PTR_ERR(priv->pmpcon);
 89
 90	priv->clk = devm_clk_get(&pdev->dev, NULL);
 91	if (IS_ERR(priv->clk))
 92		return PTR_ERR(priv->clk);
 93
 94	chip->ops = &clps711x_pwm_ops;
 95
 96	spin_lock_init(&priv->lock);
 97
 98	return devm_pwmchip_add(&pdev->dev, chip);
 99}
100
101static const struct of_device_id __maybe_unused clps711x_pwm_dt_ids[] = {
102	{ .compatible = "cirrus,ep7209-pwm", },
103	{ }
104};
105MODULE_DEVICE_TABLE(of, clps711x_pwm_dt_ids);
106
107static struct platform_driver clps711x_pwm_driver = {
108	.driver = {
109		.name = "clps711x-pwm",
110		.of_match_table = of_match_ptr(clps711x_pwm_dt_ids),
111	},
112	.probe = clps711x_pwm_probe,
113};
114module_platform_driver(clps711x_pwm_driver);
115
116MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
117MODULE_DESCRIPTION("Cirrus Logic CLPS711X PWM driver");
118MODULE_LICENSE("GPL");