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
to_clps711x_chip(struct pwm_chip * chip)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
clps711x_pwm_update_val(struct clps711x_chip * priv,u32 n,u32 v)26 static 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
clps711x_get_duty(struct pwm_device * pwm,unsigned int v)43 static 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
clps711x_pwm_request(struct pwm_chip * chip,struct pwm_device * pwm)49 static 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
clps711x_pwm_config(struct pwm_chip * chip,struct pwm_device * pwm,int duty_ns,int period_ns)63 static 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
clps711x_pwm_enable(struct pwm_chip * chip,struct pwm_device * pwm)78 static 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
clps711x_pwm_disable(struct pwm_chip * chip,struct pwm_device * pwm)89 static 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
96 static 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
clps711x_pwm_xlate(struct pwm_chip * chip,const struct of_phandle_args * args)104 static 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
clps711x_pwm_probe(struct platform_device * pdev)113 static 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
clps711x_pwm_remove(struct platform_device * pdev)145 static 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
152 static const struct of_device_id __maybe_unused clps711x_pwm_dt_ids[] = {
153 { .compatible = "cirrus,ep7209-pwm", },
154 { }
155 };
156 MODULE_DEVICE_TABLE(of, clps711x_pwm_dt_ids);
157
158 static 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 };
166 module_platform_driver(clps711x_pwm_driver);
167
168 MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
169 MODULE_DESCRIPTION("Cirrus Logic CLPS711X PWM driver");
170 MODULE_LICENSE("GPL");
171