diff options
Diffstat (limited to 'drivers/pwm/pwm-ab8500.c')
| -rw-r--r-- | drivers/pwm/pwm-ab8500.c | 153 |
1 files changed, 153 insertions, 0 deletions
diff --git a/drivers/pwm/pwm-ab8500.c b/drivers/pwm/pwm-ab8500.c new file mode 100644 index 00000000000..cfb72ca873d --- /dev/null +++ b/drivers/pwm/pwm-ab8500.c @@ -0,0 +1,153 @@ +/* + * Copyright (C) ST-Ericsson SA 2010 + * + * Author: Arun R Murthy <arun.murthy@stericsson.com> + * License terms: GNU General Public License (GPL) version 2 + */ +#include <linux/err.h> +#include <linux/platform_device.h> +#include <linux/slab.h> +#include <linux/pwm.h> +#include <linux/mfd/abx500.h> +#include <linux/mfd/abx500/ab8500.h> +#include <linux/module.h> + +/* + * PWM Out generators + * Bank: 0x10 + */ +#define AB8500_PWM_OUT_CTRL1_REG 0x60 +#define AB8500_PWM_OUT_CTRL2_REG 0x61 +#define AB8500_PWM_OUT_CTRL7_REG 0x66 + +/* backlight driver constants */ +#define ENABLE_PWM 1 +#define DISABLE_PWM 0 + +struct ab8500_pwm_chip { + struct pwm_chip chip; +}; + +static int ab8500_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, + int duty_ns, int period_ns) +{ + int ret = 0; + unsigned int higher_val, lower_val; + u8 reg; + + /* + * get the first 8 bits that are be written to + * AB8500_PWM_OUT_CTRL1_REG[0:7] + */ + lower_val = duty_ns & 0x00FF; + /* + * get bits [9:10] that are to be written to + * AB8500_PWM_OUT_CTRL2_REG[0:1] + */ + higher_val = ((duty_ns & 0x0300) >> 8); + + reg = AB8500_PWM_OUT_CTRL1_REG + ((chip->base - 1) * 2); + + ret = abx500_set_register_interruptible(chip->dev, AB8500_MISC, + reg, (u8)lower_val); + if (ret < 0) + return ret; + ret = abx500_set_register_interruptible(chip->dev, AB8500_MISC, + (reg + 1), (u8)higher_val); + + return ret; +} + +static int ab8500_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) +{ + int ret; + + ret = abx500_mask_and_set_register_interruptible(chip->dev, + AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG, + 1 << (chip->base - 1), ENABLE_PWM); + if (ret < 0) + dev_err(chip->dev, "%s: Failed to disable PWM, Error %d\n", + pwm->label, ret); + return ret; +} + +static void ab8500_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) +{ + int ret; + + ret = abx500_mask_and_set_register_interruptible(chip->dev, + AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG, + 1 << (chip->base - 1), DISABLE_PWM); + if (ret < 0) + dev_err(chip->dev, "%s: Failed to disable PWM, Error %d\n", + pwm->label, ret); + return; +} + +static const struct pwm_ops ab8500_pwm_ops = { + .config = ab8500_pwm_config, + .enable = ab8500_pwm_enable, + .disable = ab8500_pwm_disable, +}; + +static int __devinit ab8500_pwm_probe(struct platform_device *pdev) +{ + struct ab8500_pwm_chip *ab8500; + int err; + + /* + * Nothing to be done in probe, this is required to get the + * device which is required for ab8500 read and write + */ + ab8500 = kzalloc(sizeof(*ab8500), GFP_KERNEL); + if (ab8500 == NULL) { + dev_err(&pdev->dev, "failed to allocate memory\n"); + return -ENOMEM; + } + + ab8500->chip.dev = &pdev->dev; + ab8500->chip.ops = &ab8500_pwm_ops; + ab8500->chip.base = pdev->id; + ab8500->chip.npwm = 1; + + err = pwmchip_add(&ab8500->chip); + if (err < 0) { + kfree(ab8500); + return err; + } + + dev_dbg(&pdev->dev, "pwm probe successful\n"); + platform_set_drvdata(pdev, ab8500); + + return 0; +} + +static int __devexit ab8500_pwm_remove(struct platform_device *pdev) +{ + struct ab8500_pwm_chip *ab8500 = platform_get_drvdata(pdev); + int err; + + err = pwmchip_remove(&ab8500->chip); + if (err < 0) + return err; + + dev_dbg(&pdev->dev, "pwm driver removed\n"); + kfree(ab8500); + + return 0; +} + +static struct platform_driver ab8500_pwm_driver = { + .driver = { + .name = "ab8500-pwm", + .owner = THIS_MODULE, + }, + .probe = ab8500_pwm_probe, + .remove = __devexit_p(ab8500_pwm_remove), +}; +module_platform_driver(ab8500_pwm_driver); + +MODULE_AUTHOR("Arun MURTHY <arun.murthy@stericsson.com>"); +MODULE_DESCRIPTION("AB8500 Pulse Width Modulation Driver"); +MODULE_ALIAS("platform:ab8500-pwm"); +MODULE_LICENSE("GPL v2"); |