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f236d188 | 1 | // SPDX-License-Identifier: GPL-2.0+ |
7eb3f6ff AS |
2 | /* |
3 | * Cirrus Logic CLPS711X PWM driver | |
f236d188 | 4 | * Author: Alexander Shiyan <[email protected]> |
7eb3f6ff AS |
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 | ||
7eb3f6ff AS |
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(priv->clk); | |
30 | ||
31 | if (!freq) | |
32 | return -EINVAL; | |
33 | ||
34 | /* Store constant period value */ | |
e39c0df1 | 35 | pwm->args.period = DIV_ROUND_CLOSEST(NSEC_PER_SEC, freq); |
7eb3f6ff AS |
36 | |
37 | return 0; | |
38 | } | |
39 | ||
4225cd01 UKK |
40 | static int clps711x_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, |
41 | const struct pwm_state *state) | |
7eb3f6ff AS |
42 | { |
43 | struct clps711x_chip *priv = to_clps711x_chip(chip); | |
4225cd01 UKK |
44 | /* PWM0 - bits 4..7, PWM1 - bits 8..11 */ |
45 | u32 shift = (pwm->hwpwm + 1) * 4; | |
46 | unsigned long flags; | |
47 | u32 pmpcon, val; | |
7eb3f6ff | 48 | |
4225cd01 | 49 | if (state->polarity != PWM_POLARITY_NORMAL) |
7eb3f6ff AS |
50 | return -EINVAL; |
51 | ||
4225cd01 UKK |
52 | if (state->period != pwm->args.period) |
53 | return -EINVAL; | |
7eb3f6ff | 54 | |
4225cd01 UKK |
55 | if (state->enabled) |
56 | val = mul_u64_u64_div_u64(state->duty_cycle, 0xf, state->period); | |
57 | else | |
58 | val = 0; | |
7eb3f6ff | 59 | |
4225cd01 | 60 | spin_lock_irqsave(&priv->lock, flags); |
7eb3f6ff | 61 | |
4225cd01 UKK |
62 | pmpcon = readl(priv->pmpcon); |
63 | pmpcon &= ~(0xf << shift); | |
64 | pmpcon |= val << shift; | |
65 | writel(pmpcon, priv->pmpcon); | |
7eb3f6ff | 66 | |
4225cd01 | 67 | spin_unlock_irqrestore(&priv->lock, flags); |
7eb3f6ff | 68 | |
4225cd01 | 69 | return 0; |
7eb3f6ff AS |
70 | } |
71 | ||
72 | static const struct pwm_ops clps711x_pwm_ops = { | |
73 | .request = clps711x_pwm_request, | |
4225cd01 | 74 | .apply = clps711x_pwm_apply, |
7eb3f6ff AS |
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(-EINVAL); | |
83 | ||
84 | return pwm_request_from_chip(chip, args->args[0], NULL); | |
85 | } | |
86 | ||
87 | static int clps711x_pwm_probe(struct platform_device *pdev) | |
88 | { | |
89 | struct clps711x_chip *priv; | |
7eb3f6ff AS |
90 | |
91 | priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); | |
92 | if (!priv) | |
93 | return -ENOMEM; | |
94 | ||
3151b130 | 95 | priv->pmpcon = devm_platform_ioremap_resource(pdev, 0); |
7eb3f6ff AS |
96 | if (IS_ERR(priv->pmpcon)) |
97 | return PTR_ERR(priv->pmpcon); | |
98 | ||
99 | priv->clk = devm_clk_get(&pdev->dev, NULL); | |
100 | if (IS_ERR(priv->clk)) | |
101 | return PTR_ERR(priv->clk); | |
102 | ||
103 | priv->chip.ops = &clps711x_pwm_ops; | |
104 | priv->chip.dev = &pdev->dev; | |
7eb3f6ff AS |
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 | ||
9c6a02e6 | 111 | return devm_pwmchip_add(&pdev->dev, &priv->chip); |
7eb3f6ff AS |
112 | } |
113 | ||
114 | static const struct of_device_id __maybe_unused clps711x_pwm_dt_ids[] = { | |
ba60ae1d | 115 | { .compatible = "cirrus,ep7209-pwm", }, |
7eb3f6ff AS |
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", | |
7eb3f6ff AS |
123 | .of_match_table = of_match_ptr(clps711x_pwm_dt_ids), |
124 | }, | |
125 | .probe = clps711x_pwm_probe, | |
7eb3f6ff AS |
126 | }; |
127 | module_platform_driver(clps711x_pwm_driver); | |
128 | ||
129 | MODULE_AUTHOR("Alexander Shiyan <[email protected]>"); | |
130 | MODULE_DESCRIPTION("Cirrus Logic CLPS711X PWM driver"); | |
131 | MODULE_LICENSE("GPL"); |