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	struct pwm_chip chip;
 16	void __iomem *pmpcon;
 17	struct clk *clk;
 18	spinlock_t lock;
 19};
 20
 21static inline struct clps711x_chip *to_clps711x_chip(struct pwm_chip *chip)
 22{
 23	return container_of(chip, struct clps711x_chip, chip);
 24}
 25
 26static int clps711x_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
 27{
 28	struct clps711x_chip *priv = to_clps711x_chip(chip);
 29	unsigned int freq = clk_get_rate(priv->clk);
 30
 31	if (!freq)
 32		return -EINVAL;
 33
 34	/* Store constant period value */
 35	pwm->args.period = DIV_ROUND_CLOSEST(NSEC_PER_SEC, freq);
 36
 37	return 0;
 38}
 39
 40static int clps711x_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 41			      const struct pwm_state *state)
 42{
 43	struct clps711x_chip *priv = to_clps711x_chip(chip);
 44	/* PWM0 - bits 4..7, PWM1 - bits 8..11 */
 45	u32 shift = (pwm->hwpwm + 1) * 4;
 46	unsigned long flags;
 47	u32 pmpcon, val;
 48
 49	if (state->polarity != PWM_POLARITY_NORMAL)
 50		return -EINVAL;
 51
 52	if (state->period != pwm->args.period)
 53		return -EINVAL;
 54
 55	if (state->enabled)
 56		val = mul_u64_u64_div_u64(state->duty_cycle, 0xf, state->period);
 57	else
 58		val = 0;
 59
 60	spin_lock_irqsave(&priv->lock, flags);
 61
 62	pmpcon = readl(priv->pmpcon);
 63	pmpcon &= ~(0xf << shift);
 64	pmpcon |= val << shift;
 65	writel(pmpcon, priv->pmpcon);
 66
 67	spin_unlock_irqrestore(&priv->lock, flags);
 68
 69	return 0;
 70}
 71
 72static const struct pwm_ops clps711x_pwm_ops = {
 73	.request = clps711x_pwm_request,
 74	.apply = clps711x_pwm_apply,
 75};
 76
 77static struct pwm_device *clps711x_pwm_xlate(struct pwm_chip *chip,
 78					     const struct of_phandle_args *args)
 79{
 80	if (args->args[0] >= chip->npwm)
 81		return ERR_PTR(-EINVAL);
 82
 83	return pwm_request_from_chip(chip, args->args[0], NULL);
 84}
 85
 86static int clps711x_pwm_probe(struct platform_device *pdev)
 87{
 88	struct clps711x_chip *priv;
 89
 90	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
 91	if (!priv)
 92		return -ENOMEM;
 93
 94	priv->pmpcon = devm_platform_ioremap_resource(pdev, 0);
 95	if (IS_ERR(priv->pmpcon))
 96		return PTR_ERR(priv->pmpcon);
 97
 98	priv->clk = devm_clk_get(&pdev->dev, NULL);
 99	if (IS_ERR(priv->clk))
100		return PTR_ERR(priv->clk);
101
102	priv->chip.ops = &clps711x_pwm_ops;
103	priv->chip.dev = &pdev->dev;
104	priv->chip.npwm = 2;
105	priv->chip.of_xlate = clps711x_pwm_xlate;
106	priv->chip.of_pwm_n_cells = 1;
107
108	spin_lock_init(&priv->lock);
109
110	return devm_pwmchip_add(&pdev->dev, &priv->chip);
111}
112
113static const struct of_device_id __maybe_unused clps711x_pwm_dt_ids[] = {
114	{ .compatible = "cirrus,ep7209-pwm", },
115	{ }
116};
117MODULE_DEVICE_TABLE(of, clps711x_pwm_dt_ids);
118
119static struct platform_driver clps711x_pwm_driver = {
120	.driver = {
121		.name = "clps711x-pwm",
122		.of_match_table = of_match_ptr(clps711x_pwm_dt_ids),
123	},
124	.probe = clps711x_pwm_probe,
125};
126module_platform_driver(clps711x_pwm_driver);
127
128MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
129MODULE_DESCRIPTION("Cirrus Logic CLPS711X PWM driver");
130MODULE_LICENSE("GPL");