Commit | Line | Data |
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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 | ||
a4315e3c TR |
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 | ||
b2ec9efc | 106 | static const struct pwm_ops bfin_pwm_ops = { |
a4315e3c TR |
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); | |
0e1921dc | 121 | if (!pwm) |
a4315e3c | 122 | return -ENOMEM; |
a4315e3c TR |
123 | |
124 | platform_set_drvdata(pdev, pwm); | |
125 | ||
126 | pwm->chip.dev = &pdev->dev; | |
127 | pwm->chip.ops = &bfin_pwm_ops; | |
128 | pwm->chip.base = -1; | |
129 | pwm->chip.npwm = 12; | |
130 | ||
131 | ret = pwmchip_add(&pwm->chip); | |
132 | if (ret < 0) { | |
133 | dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret); | |
134 | return ret; | |
135 | } | |
136 | ||
137 | return 0; | |
138 | } | |
139 | ||
77f37917 | 140 | static int bfin_pwm_remove(struct platform_device *pdev) |
a4315e3c TR |
141 | { |
142 | struct bfin_pwm_chip *pwm = platform_get_drvdata(pdev); | |
143 | ||
b50675dc | 144 | return pwmchip_remove(&pwm->chip); |
a4315e3c TR |
145 | } |
146 | ||
147 | static struct platform_driver bfin_pwm_driver = { | |
148 | .driver = { | |
149 | .name = "bfin-pwm", | |
150 | }, | |
151 | .probe = bfin_pwm_probe, | |
fd109112 | 152 | .remove = bfin_pwm_remove, |
a4315e3c TR |
153 | }; |
154 | ||
155 | module_platform_driver(bfin_pwm_driver); | |
156 | ||
157 | MODULE_LICENSE("GPL"); |