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");
119