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 | struct pwm_chip chip; |
16 | void __iomem *pmpcon; |
17 | struct clk *clk; |
18 | spinlock_t lock; |
19 | }; |
20 | |
21 | static inline struct clps711x_chip *to_clps711x_chip(struct pwm_chip *chip) |
22 | { |
23 | return container_of(chip, struct clps711x_chip, chip); |
24 | } |
25 | |
26 | static 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(clk: 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 | |
40 | static 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(a: state->duty_cycle, mul: 0xf, div: state->period); |
57 | else |
58 | val = 0; |
59 | |
60 | spin_lock_irqsave(&priv->lock, flags); |
61 | |
62 | pmpcon = readl(addr: priv->pmpcon); |
63 | pmpcon &= ~(0xf << shift); |
64 | pmpcon |= val << shift; |
65 | writel(val: pmpcon, addr: priv->pmpcon); |
66 | |
67 | spin_unlock_irqrestore(lock: &priv->lock, flags); |
68 | |
69 | return 0; |
70 | } |
71 | |
72 | static const struct pwm_ops clps711x_pwm_ops = { |
73 | .request = clps711x_pwm_request, |
74 | .apply = clps711x_pwm_apply, |
75 | .owner = THIS_MODULE, |
76 | }; |
77 | |
78 | static struct pwm_device *clps711x_pwm_xlate(struct pwm_chip *chip, |
79 | const struct of_phandle_args *args) |
80 | { |
81 | if (args->args[0] >= chip->npwm) |
82 | return ERR_PTR(error: -EINVAL); |
83 | |
84 | return pwm_request_from_chip(chip, index: args->args[0], NULL); |
85 | } |
86 | |
87 | static int clps711x_pwm_probe(struct platform_device *pdev) |
88 | { |
89 | struct clps711x_chip *priv; |
90 | |
91 | priv = devm_kzalloc(dev: &pdev->dev, size: sizeof(*priv), GFP_KERNEL); |
92 | if (!priv) |
93 | return -ENOMEM; |
94 | |
95 | priv->pmpcon = devm_platform_ioremap_resource(pdev, index: 0); |
96 | if (IS_ERR(ptr: priv->pmpcon)) |
97 | return PTR_ERR(ptr: priv->pmpcon); |
98 | |
99 | priv->clk = devm_clk_get(dev: &pdev->dev, NULL); |
100 | if (IS_ERR(ptr: priv->clk)) |
101 | return PTR_ERR(ptr: priv->clk); |
102 | |
103 | priv->chip.ops = &clps711x_pwm_ops; |
104 | priv->chip.dev = &pdev->dev; |
105 | priv->chip.npwm = 2; |
106 | priv->chip.of_xlate = clps711x_pwm_xlate; |
107 | priv->chip.of_pwm_n_cells = 1; |
108 | |
109 | spin_lock_init(&priv->lock); |
110 | |
111 | return devm_pwmchip_add(dev: &pdev->dev, chip: &priv->chip); |
112 | } |
113 | |
114 | static const struct of_device_id __maybe_unused clps711x_pwm_dt_ids[] = { |
115 | { .compatible = "cirrus,ep7209-pwm" , }, |
116 | { } |
117 | }; |
118 | MODULE_DEVICE_TABLE(of, clps711x_pwm_dt_ids); |
119 | |
120 | static struct platform_driver clps711x_pwm_driver = { |
121 | .driver = { |
122 | .name = "clps711x-pwm" , |
123 | .of_match_table = of_match_ptr(clps711x_pwm_dt_ids), |
124 | }, |
125 | .probe = clps711x_pwm_probe, |
126 | }; |
127 | module_platform_driver(clps711x_pwm_driver); |
128 | |
129 | MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>" ); |
130 | MODULE_DESCRIPTION("Cirrus Logic CLPS711X PWM driver" ); |
131 | MODULE_LICENSE("GPL" ); |
132 | |