3.0: remove mfd_data
[linux-2.6.git] / drivers / mfd / twl6030-pwm.c
1 /*
2  * twl6030_pwm.c
3  * Driver for PHOENIX (TWL6030) Pulse Width Modulator
4  *
5  * Copyright (C) 2010 Texas Instruments
6  * Author: Hemanth V <hemanthv@ti.com>
7  *
8  * This program is free software; you can redistribute it and/or modify it
9  * under the terms of the GNU General Public License version 2 as published by
10  * the Free Software Foundation.
11  *
12  * This program is distributed in the hope that it will be useful, but WITHOUT
13  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
15  * more details.
16  *
17  * You should have received a copy of the GNU General Public License along with
18  * this program.  If not, see <http://www.gnu.org/licenses/>.
19  */
20
21 #include <linux/module.h>
22 #include <linux/platform_device.h>
23 #include <linux/i2c/twl.h>
24 #include <linux/slab.h>
25
26 #define LED_PWM_CTRL1   0xF4
27 #define LED_PWM_CTRL2   0xF5
28
29 /* Max value for CTRL1 register */
30 #define PWM_CTRL1_MAX   255
31
32 /* Pull down disable */
33 #define PWM_CTRL2_DIS_PD        (1 << 6)
34
35 /* Current control 2.5 milli Amps */
36 #define PWM_CTRL2_CURR_02       (2 << 4)
37
38 /* LED supply source */
39 #define PWM_CTRL2_SRC_VAC       (1 << 2)
40
41 /* LED modes */
42 #define PWM_CTRL2_MODE_HW       (0 << 0)
43 #define PWM_CTRL2_MODE_SW       (1 << 0)
44 #define PWM_CTRL2_MODE_DIS      (2 << 0)
45
46 #define PWM_CTRL2_MODE_MASK     0x3
47
48 struct pwm_device {
49         const char *label;
50         unsigned int pwm_id;
51 };
52
53 int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
54 {
55         u8 duty_cycle;
56         int ret;
57
58         if (pwm == NULL || period_ns == 0 || duty_ns > period_ns)
59                 return -EINVAL;
60
61         duty_cycle = (duty_ns * PWM_CTRL1_MAX) / period_ns;
62
63         ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, duty_cycle, LED_PWM_CTRL1);
64
65         if (ret < 0) {
66                 pr_err("%s: Failed to configure PWM, Error %d\n",
67                         pwm->label, ret);
68                 return ret;
69         }
70         return 0;
71 }
72 EXPORT_SYMBOL(pwm_config);
73
74 int pwm_enable(struct pwm_device *pwm)
75 {
76         u8 val;
77         int ret;
78
79         ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, LED_PWM_CTRL2);
80         if (ret < 0) {
81                 pr_err("%s: Failed to enable PWM, Error %d\n", pwm->label, ret);
82                 return ret;
83         }
84
85         /* Change mode to software control */
86         val &= ~PWM_CTRL2_MODE_MASK;
87         val |= PWM_CTRL2_MODE_SW;
88
89         ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, LED_PWM_CTRL2);
90         if (ret < 0) {
91                 pr_err("%s: Failed to enable PWM, Error %d\n", pwm->label, ret);
92                 return ret;
93         }
94
95         twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, LED_PWM_CTRL2);
96         return 0;
97 }
98 EXPORT_SYMBOL(pwm_enable);
99
100 void pwm_disable(struct pwm_device *pwm)
101 {
102         u8 val;
103         int ret;
104
105         ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, LED_PWM_CTRL2);
106         if (ret < 0) {
107                 pr_err("%s: Failed to disable PWM, Error %d\n",
108                         pwm->label, ret);
109                 return;
110         }
111
112         val &= ~PWM_CTRL2_MODE_MASK;
113         val |= PWM_CTRL2_MODE_HW;
114
115         ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, LED_PWM_CTRL2);
116         if (ret < 0) {
117                 pr_err("%s: Failed to disable PWM, Error %d\n",
118                         pwm->label, ret);
119                 return;
120         }
121         return;
122 }
123 EXPORT_SYMBOL(pwm_disable);
124
125 struct pwm_device *pwm_request(int pwm_id, const char *label)
126 {
127         u8 val;
128         int ret;
129         struct pwm_device *pwm;
130
131         pwm = kzalloc(sizeof(struct pwm_device), GFP_KERNEL);
132         if (pwm == NULL) {
133                 pr_err("%s: failed to allocate memory\n", label);
134                 return NULL;
135         }
136
137         pwm->label = label;
138         pwm->pwm_id = pwm_id;
139
140         /* Configure PWM */
141         val = PWM_CTRL2_DIS_PD | PWM_CTRL2_CURR_02 | PWM_CTRL2_SRC_VAC |
142                 PWM_CTRL2_MODE_HW;
143
144         ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, LED_PWM_CTRL2);
145
146         if (ret < 0) {
147                 pr_err("%s: Failed to configure PWM, Error %d\n",
148                          pwm->label, ret);
149
150                 kfree(pwm);
151                 return NULL;
152         }
153
154         return pwm;
155 }
156 EXPORT_SYMBOL(pwm_request);
157
158 void pwm_free(struct pwm_device *pwm)
159 {
160         pwm_disable(pwm);
161         kfree(pwm);
162 }
163 EXPORT_SYMBOL(pwm_free);
164
165 MODULE_LICENSE("GPL");