GNU Linux-libre 4.9.326-gnu1
[releases.git] / drivers / pwm / pwm-bfin.c
1 /*
2  * Blackfin Pulse Width Modulation (PWM) core
3  *
4  * Copyright (c) 2011 Analog Devices Inc.
5  *
6  * Licensed under the GPL-2 or later.
7  */
8
9 #include <linux/module.h>
10 #include <linux/platform_device.h>
11 #include <linux/pwm.h>
12 #include <linux/slab.h>
13
14 #include <asm/gptimers.h>
15 #include <asm/portmux.h>
16
17 struct bfin_pwm_chip {
18         struct pwm_chip chip;
19 };
20
21 struct bfin_pwm {
22         unsigned short pin;
23 };
24
25 static const unsigned short pwm_to_gptimer_per[] = {
26         P_TMR0, P_TMR1, P_TMR2, P_TMR3, P_TMR4, P_TMR5,
27         P_TMR6, P_TMR7, P_TMR8, P_TMR9, P_TMR10, P_TMR11,
28 };
29
30 static int bfin_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
31 {
32         struct bfin_pwm *priv;
33         int ret;
34
35         if (pwm->hwpwm >= ARRAY_SIZE(pwm_to_gptimer_per))
36                 return -EINVAL;
37
38         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
39         if (!priv)
40                 return -ENOMEM;
41
42         priv->pin = pwm_to_gptimer_per[pwm->hwpwm];
43
44         ret = peripheral_request(priv->pin, NULL);
45         if (ret) {
46                 kfree(priv);
47                 return ret;
48         }
49
50         pwm_set_chip_data(pwm, priv);
51
52         return 0;
53 }
54
55 static void bfin_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
56 {
57         struct bfin_pwm *priv = pwm_get_chip_data(pwm);
58
59         if (priv) {
60                 peripheral_free(priv->pin);
61                 kfree(priv);
62         }
63 }
64
65 static int bfin_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
66                 int duty_ns, int period_ns)
67 {
68         struct bfin_pwm *priv = pwm_get_chip_data(pwm);
69         unsigned long period, duty;
70         unsigned long long val;
71
72         val = (unsigned long long)get_sclk() * period_ns;
73         do_div(val, NSEC_PER_SEC);
74         period = val;
75
76         val = (unsigned long long)period * duty_ns;
77         do_div(val, period_ns);
78         duty = period - val;
79
80         if (duty >= period)
81                 duty = period - 1;
82
83         set_gptimer_config(priv->pin, TIMER_MODE_PWM | TIMER_PERIOD_CNT);
84         set_gptimer_pwidth(priv->pin, duty);
85         set_gptimer_period(priv->pin, period);
86
87         return 0;
88 }
89
90 static int bfin_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
91 {
92         struct bfin_pwm *priv = pwm_get_chip_data(pwm);
93
94         enable_gptimer(priv->pin);
95
96         return 0;
97 }
98
99 static void bfin_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
100 {
101         struct bfin_pwm *priv = pwm_get_chip_data(pwm);
102
103         disable_gptimer(priv->pin);
104 }
105
106 static struct pwm_ops bfin_pwm_ops = {
107         .request = bfin_pwm_request,
108         .free = bfin_pwm_free,
109         .config = bfin_pwm_config,
110         .enable = bfin_pwm_enable,
111         .disable = bfin_pwm_disable,
112         .owner = THIS_MODULE,
113 };
114
115 static int bfin_pwm_probe(struct platform_device *pdev)
116 {
117         struct bfin_pwm_chip *pwm;
118         int ret;
119
120         pwm = devm_kzalloc(&pdev->dev, sizeof(*pwm), GFP_KERNEL);
121         if (!pwm) {
122                 dev_err(&pdev->dev, "failed to allocate memory\n");
123                 return -ENOMEM;
124         }
125
126         platform_set_drvdata(pdev, pwm);
127
128         pwm->chip.dev = &pdev->dev;
129         pwm->chip.ops = &bfin_pwm_ops;
130         pwm->chip.base = -1;
131         pwm->chip.npwm = 12;
132
133         ret = pwmchip_add(&pwm->chip);
134         if (ret < 0) {
135                 dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
136                 return ret;
137         }
138
139         return 0;
140 }
141
142 static int bfin_pwm_remove(struct platform_device *pdev)
143 {
144         struct bfin_pwm_chip *pwm = platform_get_drvdata(pdev);
145
146         return pwmchip_remove(&pwm->chip);
147 }
148
149 static struct platform_driver bfin_pwm_driver = {
150         .driver = {
151                 .name = "bfin-pwm",
152         },
153         .probe = bfin_pwm_probe,
154         .remove = bfin_pwm_remove,
155 };
156
157 module_platform_driver(bfin_pwm_driver);
158
159 MODULE_LICENSE("GPL");