diff options
Diffstat (limited to 'drivers/pwm/pwm-twl6030.c')
| -rw-r--r-- | drivers/pwm/pwm-twl6030.c | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/drivers/pwm/pwm-twl6030.c b/drivers/pwm/pwm-twl6030.c new file mode 100644 index 0000000..8e63878 --- /dev/null +++ b/drivers/pwm/pwm-twl6030.c @@ -0,0 +1,184 @@ +/* + * twl6030_pwm.c + * Driver for PHOENIX (TWL6030) Pulse Width Modulator + * + * Copyright (C) 2010 Texas Instruments + * Author: Hemanth V <hemanthv@ti.com> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published by + * the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along with + * this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/pwm.h> +#include <linux/i2c/twl.h> +#include <linux/slab.h> + +#define LED_PWM_CTRL1 0xF4 +#define LED_PWM_CTRL2 0xF5 + +/* Max value for CTRL1 register */ +#define PWM_CTRL1_MAX 255 + +/* Pull down disable */ +#define PWM_CTRL2_DIS_PD (1 << 6) + +/* Current control 2.5 milli Amps */ +#define PWM_CTRL2_CURR_02 (2 << 4) + +/* LED supply source */ +#define PWM_CTRL2_SRC_VAC (1 << 2) + +/* LED modes */ +#define PWM_CTRL2_MODE_HW (0 << 0) +#define PWM_CTRL2_MODE_SW (1 << 0) +#define PWM_CTRL2_MODE_DIS (2 << 0) + +#define PWM_CTRL2_MODE_MASK 0x3 + +struct twl6030_pwm_chip { + struct pwm_chip chip; +}; + +static int twl6030_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm) +{ + int ret; + u8 val; + + /* Configure PWM */ + val = PWM_CTRL2_DIS_PD | PWM_CTRL2_CURR_02 | PWM_CTRL2_SRC_VAC | + PWM_CTRL2_MODE_HW; + + ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, LED_PWM_CTRL2); + if (ret < 0) { + dev_err(chip->dev, "%s: Failed to configure PWM, Error %d\n", + pwm->label, ret); + return ret; + } + + return 0; +} + +static int twl6030_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, + int duty_ns, int period_ns) +{ + u8 duty_cycle = (duty_ns * PWM_CTRL1_MAX) / period_ns; + int ret; + + ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, duty_cycle, LED_PWM_CTRL1); + if (ret < 0) { + pr_err("%s: Failed to configure PWM, Error %d\n", + pwm->label, ret); + return ret; + } + + return 0; +} + +static int twl6030_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) +{ + int ret; + u8 val; + + ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, LED_PWM_CTRL2); + if (ret < 0) { + dev_err(chip->dev, "%s: Failed to enable PWM, Error %d\n", + pwm->label, ret); + return ret; + } + + /* Change mode to software control */ + val &= ~PWM_CTRL2_MODE_MASK; + val |= PWM_CTRL2_MODE_SW; + + ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, LED_PWM_CTRL2); + if (ret < 0) { + dev_err(chip->dev, "%s: Failed to enable PWM, Error %d\n", + pwm->label, ret); + return ret; + } + + twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, LED_PWM_CTRL2); + return 0; +} + +static void twl6030_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) +{ + int ret; + u8 val; + + ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, LED_PWM_CTRL2); + if (ret < 0) { + dev_err(chip->dev, "%s: Failed to disable PWM, Error %d\n", + pwm->label, ret); + return; + } + + val &= ~PWM_CTRL2_MODE_MASK; + val |= PWM_CTRL2_MODE_HW; + + ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, LED_PWM_CTRL2); + if (ret < 0) { + dev_err(chip->dev, "%s: Failed to disable PWM, Error %d\n", + pwm->label, ret); + } +} + +static const struct pwm_ops twl6030_pwm_ops = { + .request = twl6030_pwm_request, + .config = twl6030_pwm_config, + .enable = twl6030_pwm_enable, + .disable = twl6030_pwm_disable, +}; + +static int twl6030_pwm_probe(struct platform_device *pdev) +{ + struct twl6030_pwm_chip *twl6030; + int ret; + + twl6030 = devm_kzalloc(&pdev->dev, sizeof(*twl6030), GFP_KERNEL); + if (!twl6030) + return -ENOMEM; + + twl6030->chip.dev = &pdev->dev; + twl6030->chip.ops = &twl6030_pwm_ops; + twl6030->chip.base = -1; + twl6030->chip.npwm = 1; + + ret = pwmchip_add(&twl6030->chip); + if (ret < 0) + return ret; + + platform_set_drvdata(pdev, twl6030); + + return 0; +} + +static int twl6030_pwm_remove(struct platform_device *pdev) +{ + struct twl6030_pwm_chip *twl6030 = platform_get_drvdata(pdev); + + return pwmchip_remove(&twl6030->chip); +} + +static struct platform_driver twl6030_pwm_driver = { + .driver = { + .name = "twl6030-pwm", + }, + .probe = twl6030_pwm_probe, + .remove = __devexit_p(twl6030_pwm_remove), +}; +module_platform_driver(twl6030_pwm_driver); + +MODULE_ALIAS("platform:twl6030-pwm"); +MODULE_LICENSE("GPL"); |
