misc: tegra-baseband: Add usb core notification support.
[linux-2.6.git] / drivers / misc / ab8500-pwm.c
1 /*
2  * Copyright (C) ST-Ericsson SA 2010
3  *
4  * Author: Arun R Murthy <arun.murthy@stericsson.com>
5  * License terms: GNU General Public License (GPL) version 2
6  */
7 #include <linux/err.h>
8 #include <linux/platform_device.h>
9 #include <linux/slab.h>
10 #include <linux/pwm.h>
11 #include <linux/mfd/ab8500.h>
12 #include <linux/mfd/abx500.h>
13
14 /*
15  * PWM Out generators
16  * Bank: 0x10
17  */
18 #define AB8500_PWM_OUT_CTRL1_REG        0x60
19 #define AB8500_PWM_OUT_CTRL2_REG        0x61
20 #define AB8500_PWM_OUT_CTRL7_REG        0x66
21
22 /* backlight driver constants */
23 #define ENABLE_PWM                      1
24 #define DISABLE_PWM                     0
25
26 struct pwm_device {
27         struct device *dev;
28         struct list_head node;
29         const char *label;
30         unsigned int pwm_id;
31 };
32
33 static LIST_HEAD(pwm_list);
34
35 int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
36 {
37         int ret = 0;
38         unsigned int higher_val, lower_val;
39         u8 reg;
40
41         /*
42          * get the first 8 bits that are be written to
43          * AB8500_PWM_OUT_CTRL1_REG[0:7]
44          */
45         lower_val = duty_ns & 0x00FF;
46         /*
47          * get bits [9:10] that are to be written to
48          * AB8500_PWM_OUT_CTRL2_REG[0:1]
49          */
50         higher_val = ((duty_ns & 0x0300) >> 8);
51
52         reg = AB8500_PWM_OUT_CTRL1_REG + ((pwm->pwm_id - 1) * 2);
53
54         ret = abx500_set_register_interruptible(pwm->dev, AB8500_MISC,
55                         reg, (u8)lower_val);
56         if (ret < 0)
57                 return ret;
58         ret = abx500_set_register_interruptible(pwm->dev, AB8500_MISC,
59                         (reg + 1), (u8)higher_val);
60
61         return ret;
62 }
63 EXPORT_SYMBOL(pwm_config);
64
65 int pwm_enable(struct pwm_device *pwm)
66 {
67         int ret;
68
69         ret = abx500_mask_and_set_register_interruptible(pwm->dev,
70                                 AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG,
71                                 1 << (pwm->pwm_id-1), ENABLE_PWM);
72         if (ret < 0)
73                 dev_err(pwm->dev, "%s: Failed to disable PWM, Error %d\n",
74                                                         pwm->label, ret);
75         return ret;
76 }
77 EXPORT_SYMBOL(pwm_enable);
78
79 void pwm_disable(struct pwm_device *pwm)
80 {
81         int ret;
82
83         ret = abx500_mask_and_set_register_interruptible(pwm->dev,
84                                 AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG,
85                                 1 << (pwm->pwm_id-1), DISABLE_PWM);
86         if (ret < 0)
87                 dev_err(pwm->dev, "%s: Failed to disable PWM, Error %d\n",
88                                                         pwm->label, ret);
89         return;
90 }
91 EXPORT_SYMBOL(pwm_disable);
92
93 struct pwm_device *pwm_request(int pwm_id, const char *label)
94 {
95         struct pwm_device *pwm;
96
97         list_for_each_entry(pwm, &pwm_list, node) {
98                 if (pwm->pwm_id == pwm_id) {
99                         pwm->label = label;
100                         pwm->pwm_id = pwm_id;
101                         return pwm;
102                 }
103         }
104
105         return ERR_PTR(-ENOENT);
106 }
107 EXPORT_SYMBOL(pwm_request);
108
109 void pwm_free(struct pwm_device *pwm)
110 {
111         pwm_disable(pwm);
112 }
113 EXPORT_SYMBOL(pwm_free);
114
115 static int __devinit ab8500_pwm_probe(struct platform_device *pdev)
116 {
117         struct pwm_device *pwm;
118         /*
119          * Nothing to be done in probe, this is required to get the
120          * device which is required for ab8500 read and write
121          */
122         pwm = kzalloc(sizeof(struct pwm_device), GFP_KERNEL);
123         if (pwm == NULL) {
124                 dev_err(&pdev->dev, "failed to allocate memory\n");
125                 return -ENOMEM;
126         }
127         pwm->dev = &pdev->dev;
128         pwm->pwm_id = pdev->id;
129         list_add_tail(&pwm->node, &pwm_list);
130         platform_set_drvdata(pdev, pwm);
131         dev_dbg(pwm->dev, "pwm probe successful\n");
132         return 0;
133 }
134
135 static int __devexit ab8500_pwm_remove(struct platform_device *pdev)
136 {
137         struct pwm_device *pwm = platform_get_drvdata(pdev);
138         list_del(&pwm->node);
139         dev_dbg(&pdev->dev, "pwm driver removed\n");
140         kfree(pwm);
141         return 0;
142 }
143
144 static struct platform_driver ab8500_pwm_driver = {
145         .driver = {
146                 .name = "ab8500-pwm",
147                 .owner = THIS_MODULE,
148         },
149         .probe = ab8500_pwm_probe,
150         .remove = __devexit_p(ab8500_pwm_remove),
151 };
152
153 static int __init ab8500_pwm_init(void)
154 {
155         return platform_driver_register(&ab8500_pwm_driver);
156 }
157
158 static void __exit ab8500_pwm_exit(void)
159 {
160         platform_driver_unregister(&ab8500_pwm_driver);
161 }
162
163 subsys_initcall(ab8500_pwm_init);
164 module_exit(ab8500_pwm_exit);
165 MODULE_AUTHOR("Arun MURTHY <arun.murthy@stericsson.com>");
166 MODULE_DESCRIPTION("AB8500 Pulse Width Modulation Driver");
167 MODULE_ALIAS("platform:ab8500-pwm");
168 MODULE_LICENSE("GPL v2");