3 * Driver for PHOENIX (TWL6030) Pulse Width Modulator
5 * Copyright (C) 2010 Texas Instruments
6 * Author: Hemanth V <hemanthv@ti.com>
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.
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
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/>.
21 #include <linux/module.h>
22 #include <linux/platform_device.h>
23 #include <linux/pwm.h>
24 #include <linux/i2c/twl.h>
25 #include <linux/slab.h>
27 #define LED_PWM_CTRL1 0xF4
28 #define LED_PWM_CTRL2 0xF5
30 /* Max value for CTRL1 register */
31 #define PWM_CTRL1_MAX 255
33 /* Pull down disable */
34 #define PWM_CTRL2_DIS_PD (1 << 6)
36 /* Current control 2.5 milli Amps */
37 #define PWM_CTRL2_CURR_02 (2 << 4)
39 /* LED supply source */
40 #define PWM_CTRL2_SRC_VAC (1 << 2)
43 #define PWM_CTRL2_MODE_HW (0 << 0)
44 #define PWM_CTRL2_MODE_SW (1 << 0)
45 #define PWM_CTRL2_MODE_DIS (2 << 0)
47 #define PWM_CTRL2_MODE_MASK 0x3
49 struct twl6030_pwm_chip {
53 static int twl6030_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
59 val = PWM_CTRL2_DIS_PD | PWM_CTRL2_CURR_02 | PWM_CTRL2_SRC_VAC |
62 ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, LED_PWM_CTRL2);
64 dev_err(chip->dev, "%s: Failed to configure PWM, Error %d\n",
72 static int twl6030_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
73 int duty_ns, int period_ns)
75 u8 duty_cycle = (duty_ns * PWM_CTRL1_MAX) / period_ns;
78 ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, duty_cycle, LED_PWM_CTRL1);
80 pr_err("%s: Failed to configure PWM, Error %d\n",
88 static int twl6030_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
93 ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, LED_PWM_CTRL2);
95 dev_err(chip->dev, "%s: Failed to enable PWM, Error %d\n",
100 /* Change mode to software control */
101 val &= ~PWM_CTRL2_MODE_MASK;
102 val |= PWM_CTRL2_MODE_SW;
104 ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, LED_PWM_CTRL2);
106 dev_err(chip->dev, "%s: Failed to enable PWM, Error %d\n",
111 twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, LED_PWM_CTRL2);
115 static void twl6030_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
120 ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, LED_PWM_CTRL2);
122 dev_err(chip->dev, "%s: Failed to disable PWM, Error %d\n",
127 val &= ~PWM_CTRL2_MODE_MASK;
128 val |= PWM_CTRL2_MODE_HW;
130 ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, LED_PWM_CTRL2);
132 dev_err(chip->dev, "%s: Failed to disable PWM, Error %d\n",
137 static const struct pwm_ops twl6030_pwm_ops = {
138 .request = twl6030_pwm_request,
139 .config = twl6030_pwm_config,
140 .enable = twl6030_pwm_enable,
141 .disable = twl6030_pwm_disable,
144 static int twl6030_pwm_probe(struct platform_device *pdev)
146 struct twl6030_pwm_chip *twl6030;
149 twl6030 = devm_kzalloc(&pdev->dev, sizeof(*twl6030), GFP_KERNEL);
153 twl6030->chip.dev = &pdev->dev;
154 twl6030->chip.ops = &twl6030_pwm_ops;
155 twl6030->chip.base = -1;
156 twl6030->chip.npwm = 1;
158 ret = pwmchip_add(&twl6030->chip);
162 platform_set_drvdata(pdev, twl6030);
167 static int twl6030_pwm_remove(struct platform_device *pdev)
169 struct twl6030_pwm_chip *twl6030 = platform_get_drvdata(pdev);
171 return pwmchip_remove(&twl6030->chip);
174 static struct platform_driver twl6030_pwm_driver = {
176 .name = "twl6030-pwm",
178 .probe = twl6030_pwm_probe,
179 .remove = twl6030_pwm_remove,
181 module_platform_driver(twl6030_pwm_driver);
183 MODULE_ALIAS("platform:twl6030-pwm");
184 MODULE_LICENSE("GPL");