/* * 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/ab8500.h> #include <linux/mfd/abx500.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 pwm_device { struct device *dev; struct list_head node; const char *label; unsigned int pwm_id; }; static LIST_HEAD(pwm_list); int pwm_config(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 + ((pwm->pwm_id - 1) * 2); ret = abx500_set_register_interruptible(pwm->dev, AB8500_MISC, reg, (u8)lower_val); if (ret < 0) return ret; ret = abx500_set_register_interruptible(pwm->dev, AB8500_MISC, (reg + 1), (u8)higher_val); return ret; } EXPORT_SYMBOL(pwm_config); int pwm_enable(struct pwm_device *pwm) { int ret; ret = abx500_mask_and_set_register_interruptible(pwm->dev, AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG, 1 << (pwm->pwm_id-1), ENABLE_PWM); if (ret < 0) dev_err(pwm->dev, "%s: Failed to disable PWM, Error %d\n", pwm->label, ret); return ret; } EXPORT_SYMBOL(pwm_enable); void pwm_disable(struct pwm_device *pwm) { int ret; ret = abx500_mask_and_set_register_interruptible(pwm->dev, AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG, 1 << (pwm->pwm_id-1), DISABLE_PWM); if (ret < 0) dev_err(pwm->dev, "%s: Failed to disable PWM, Error %d\n", pwm->label, ret); return; } EXPORT_SYMBOL(pwm_disable); struct pwm_device *pwm_request(int pwm_id, const char *label) { struct pwm_device *pwm; list_for_each_entry(pwm, &pwm_list, node) { if (pwm->pwm_id == pwm_id) { pwm->label = label; pwm->pwm_id = pwm_id; return pwm; } } return ERR_PTR(-ENOENT); } EXPORT_SYMBOL(pwm_request); void pwm_free(struct pwm_device *pwm) { pwm_disable(pwm); } EXPORT_SYMBOL(pwm_free); static int __devinit ab8500_pwm_probe(struct platform_device *pdev) { struct pwm_device *pwm; /* * Nothing to be done in probe, this is required to get the * device which is required for ab8500 read and write */ pwm = kzalloc(sizeof(struct pwm_device), GFP_KERNEL); if (pwm == NULL) { dev_err(&pdev->dev, "failed to allocate memory\n"); return -ENOMEM; } pwm->dev = &pdev->dev; pwm->pwm_id = pdev->id; list_add_tail(&pwm->node, &pwm_list); platform_set_drvdata(pdev, pwm); dev_dbg(pwm->dev, "pwm probe successful\n"); return 0; } static int __devexit ab8500_pwm_remove(struct platform_device *pdev) { struct pwm_device *pwm = platform_get_drvdata(pdev); list_del(&pwm->node); dev_dbg(&pdev->dev, "pwm driver removed\n"); kfree(pwm); 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), }; static int __init ab8500_pwm_init(void) { return platform_driver_register(&ab8500_pwm_driver); } static void __exit ab8500_pwm_exit(void) { platform_driver_unregister(&ab8500_pwm_driver); } subsys_initcall(ab8500_pwm_init); module_exit(ab8500_pwm_exit); MODULE_AUTHOR("Arun MURTHY <arun.murthy@stericsson.com>"); MODULE_DESCRIPTION("AB8500 Pulse Width Modulation Driver"); MODULE_ALIAS("AB8500 PWM driver"); MODULE_LICENSE("GPL v2");