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 void clps711x_pwm_update_val(struct clps711x_chip *priv, u32 n, u32 v)
27{
28	/* PWM0 - bits 4..7, PWM1 - bits 8..11 */
29	u32 shift = (n + 1) * 4;
30	unsigned long flags;
31	u32 tmp;
32
33	spin_lock_irqsave(&priv->lock, flags);
34
35	tmp = readl(priv->pmpcon);
36	tmp &= ~(0xf << shift);
37	tmp |= v << shift;
38	writel(tmp, priv->pmpcon);
39
40	spin_unlock_irqrestore(&priv->lock, flags);
41}
42
43static unsigned int clps711x_get_duty(struct pwm_device *pwm, unsigned int v)
44{
45	/* Duty cycle 0..15 max */
46	return DIV64_U64_ROUND_CLOSEST(v * 0xf, pwm->args.period);
47}
48
49static int clps711x_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
50{
51	struct clps711x_chip *priv = to_clps711x_chip(chip);
52	unsigned int freq = clk_get_rate(priv->clk);
53
54	if (!freq)
55		return -EINVAL;
56
57	/* Store constant period value */
58	pwm->args.period = DIV_ROUND_CLOSEST(NSEC_PER_SEC, freq);
59
60	return 0;
61}
62
63static int clps711x_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
64			       int duty_ns, int period_ns)
65{
66	struct clps711x_chip *priv = to_clps711x_chip(chip);
67	unsigned int duty;
68
69	if (period_ns != pwm->args.period)
70		return -EINVAL;
71
72	duty = clps711x_get_duty(pwm, duty_ns);
73	clps711x_pwm_update_val(priv, pwm->hwpwm, duty);
74
75	return 0;
76}
77
78static int clps711x_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
79{
80	struct clps711x_chip *priv = to_clps711x_chip(chip);
81	unsigned int duty;
82
83	duty = clps711x_get_duty(pwm, pwm_get_duty_cycle(pwm));
84	clps711x_pwm_update_val(priv, pwm->hwpwm, duty);
85
86	return 0;
87}
88
89static void clps711x_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
90{
91	struct clps711x_chip *priv = to_clps711x_chip(chip);
92
93	clps711x_pwm_update_val(priv, pwm->hwpwm, 0);
94}
95
96static const struct pwm_ops clps711x_pwm_ops = {
97	.request = clps711x_pwm_request,
98	.config = clps711x_pwm_config,
99	.enable = clps711x_pwm_enable,
100	.disable = clps711x_pwm_disable,
101	.owner = THIS_MODULE,
102};
103
104static struct pwm_device *clps711x_pwm_xlate(struct pwm_chip *chip,
105					     const struct of_phandle_args *args)
106{
107	if (args->args[0] >= chip->npwm)
108		return ERR_PTR(-EINVAL);
109
110	return pwm_request_from_chip(chip, args->args[0], NULL);
111}
112
113static int clps711x_pwm_probe(struct platform_device *pdev)
114{
115	struct clps711x_chip *priv;
116	struct resource *res;
117
118	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
119	if (!priv)
120		return -ENOMEM;
121
122	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
123	priv->pmpcon = devm_ioremap_resource(&pdev->dev, res);
124	if (IS_ERR(priv->pmpcon))
125		return PTR_ERR(priv->pmpcon);
126
127	priv->clk = devm_clk_get(&pdev->dev, NULL);
128	if (IS_ERR(priv->clk))
129		return PTR_ERR(priv->clk);
130
131	priv->chip.ops = &clps711x_pwm_ops;
132	priv->chip.dev = &pdev->dev;
133	priv->chip.base = -1;
134	priv->chip.npwm = 2;
135	priv->chip.of_xlate = clps711x_pwm_xlate;
136	priv->chip.of_pwm_n_cells = 1;
137
138	spin_lock_init(&priv->lock);
139
140	platform_set_drvdata(pdev, priv);
141
142	return pwmchip_add(&priv->chip);
143}
144
145static int clps711x_pwm_remove(struct platform_device *pdev)
146{
147	struct clps711x_chip *priv = platform_get_drvdata(pdev);
148
149	return pwmchip_remove(&priv->chip);
150}
151
152static const struct of_device_id __maybe_unused clps711x_pwm_dt_ids[] = {
153	{ .compatible = "cirrus,ep7209-pwm", },
154	{ }
155};
156MODULE_DEVICE_TABLE(of, clps711x_pwm_dt_ids);
157
158static struct platform_driver clps711x_pwm_driver = {
159	.driver = {
160		.name = "clps711x-pwm",
161		.of_match_table = of_match_ptr(clps711x_pwm_dt_ids),
162	},
163	.probe = clps711x_pwm_probe,
164	.remove = clps711x_pwm_remove,
165};
166module_platform_driver(clps711x_pwm_driver);
167
168MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
169MODULE_DESCRIPTION("Cirrus Logic CLPS711X PWM driver");
170MODULE_LICENSE("GPL");
171