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a4315e3c TR |
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 | if (duty_ns < 0 || duty_ns > period_ns) | |
73 | return -EINVAL; | |
74 | ||
75 | val = (unsigned long long)get_sclk() * period_ns; | |
76 | do_div(val, NSEC_PER_SEC); | |
77 | period = val; | |
78 | ||
79 | val = (unsigned long long)period * duty_ns; | |
80 | do_div(val, period_ns); | |
81 | duty = period - val; | |
82 | ||
83 | if (duty >= period) | |
84 | duty = period - 1; | |
85 | ||
86 | set_gptimer_config(priv->pin, TIMER_MODE_PWM | TIMER_PERIOD_CNT); | |
87 | set_gptimer_pwidth(priv->pin, duty); | |
88 | set_gptimer_period(priv->pin, period); | |
89 | ||
90 | return 0; | |
91 | } | |
92 | ||
93 | static int bfin_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) | |
94 | { | |
95 | struct bfin_pwm *priv = pwm_get_chip_data(pwm); | |
96 | ||
97 | enable_gptimer(priv->pin); | |
98 | ||
99 | return 0; | |
100 | } | |
101 | ||
102 | static void bfin_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) | |
103 | { | |
104 | struct bfin_pwm *priv = pwm_get_chip_data(pwm); | |
105 | ||
106 | disable_gptimer(priv->pin); | |
107 | } | |
108 | ||
109 | static struct pwm_ops bfin_pwm_ops = { | |
110 | .request = bfin_pwm_request, | |
111 | .free = bfin_pwm_free, | |
112 | .config = bfin_pwm_config, | |
113 | .enable = bfin_pwm_enable, | |
114 | .disable = bfin_pwm_disable, | |
115 | .owner = THIS_MODULE, | |
116 | }; | |
117 | ||
118 | static int bfin_pwm_probe(struct platform_device *pdev) | |
119 | { | |
120 | struct bfin_pwm_chip *pwm; | |
121 | int ret; | |
122 | ||
123 | pwm = devm_kzalloc(&pdev->dev, sizeof(*pwm), GFP_KERNEL); | |
124 | if (!pwm) { | |
125 | dev_err(&pdev->dev, "failed to allocate memory\n"); | |
126 | return -ENOMEM; | |
127 | } | |
128 | ||
129 | platform_set_drvdata(pdev, pwm); | |
130 | ||
131 | pwm->chip.dev = &pdev->dev; | |
132 | pwm->chip.ops = &bfin_pwm_ops; | |
133 | pwm->chip.base = -1; | |
134 | pwm->chip.npwm = 12; | |
135 | ||
136 | ret = pwmchip_add(&pwm->chip); | |
137 | if (ret < 0) { | |
138 | dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret); | |
139 | return ret; | |
140 | } | |
141 | ||
142 | return 0; | |
143 | } | |
144 | ||
145 | static int __devexit bfin_pwm_remove(struct platform_device *pdev) | |
146 | { | |
147 | struct bfin_pwm_chip *pwm = platform_get_drvdata(pdev); | |
148 | ||
b50675dc | 149 | return pwmchip_remove(&pwm->chip); |
a4315e3c TR |
150 | } |
151 | ||
152 | static struct platform_driver bfin_pwm_driver = { | |
153 | .driver = { | |
154 | .name = "bfin-pwm", | |
155 | }, | |
156 | .probe = bfin_pwm_probe, | |
157 | .remove = __devexit_p(bfin_pwm_remove), | |
158 | }; | |
159 | ||
160 | module_platform_driver(bfin_pwm_driver); | |
161 | ||
162 | MODULE_LICENSE("GPL"); |