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 | |
14 | struct clps711x_chip { |
15 | void __iomem *pmpcon; |
16 | struct clk *clk; |
17 | spinlock_t lock; |
18 | }; |
19 | |
20 | static inline struct clps711x_chip *to_clps711x_chip(struct pwm_chip *chip) |
21 | { |
22 | return pwmchip_get_drvdata(chip); |
23 | } |
24 | |
25 | static 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(clk: 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 | |
39 | static 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(a: state->duty_cycle, mul: 0xf, div: state->period); |
56 | else |
57 | val = 0; |
58 | |
59 | spin_lock_irqsave(&priv->lock, flags); |
60 | |
61 | pmpcon = readl(addr: priv->pmpcon); |
62 | pmpcon &= ~(0xf << shift); |
63 | pmpcon |= val << shift; |
64 | writel(val: pmpcon, addr: priv->pmpcon); |
65 | |
66 | spin_unlock_irqrestore(lock: &priv->lock, flags); |
67 | |
68 | return 0; |
69 | } |
70 | |
71 | static const struct pwm_ops clps711x_pwm_ops = { |
72 | .request = clps711x_pwm_request, |
73 | .apply = clps711x_pwm_apply, |
74 | }; |
75 | |
76 | static 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(parent: &pdev->dev, npwm: 2, sizeof_priv: sizeof(*priv)); |
82 | if (IS_ERR(ptr: chip)) |
83 | return PTR_ERR(ptr: chip); |
84 | priv = to_clps711x_chip(chip); |
85 | |
86 | priv->pmpcon = devm_platform_ioremap_resource(pdev, index: 0); |
87 | if (IS_ERR(ptr: priv->pmpcon)) |
88 | return PTR_ERR(ptr: priv->pmpcon); |
89 | |
90 | priv->clk = devm_clk_get(dev: &pdev->dev, NULL); |
91 | if (IS_ERR(ptr: priv->clk)) |
92 | return PTR_ERR(ptr: 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 | |
101 | static const struct of_device_id __maybe_unused clps711x_pwm_dt_ids[] = { |
102 | { .compatible = "cirrus,ep7209-pwm" , }, |
103 | { } |
104 | }; |
105 | MODULE_DEVICE_TABLE(of, clps711x_pwm_dt_ids); |
106 | |
107 | static 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 | }; |
114 | module_platform_driver(clps711x_pwm_driver); |
115 | |
116 | MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>" ); |
117 | MODULE_DESCRIPTION("Cirrus Logic CLPS711X PWM driver" ); |
118 | MODULE_LICENSE("GPL" ); |
119 | |