diff options
Diffstat (limited to 'arch/arm/plat-samsung/pwm.c')
-rw-r--r-- | arch/arm/plat-samsung/pwm.c | 416 |
1 files changed, 0 insertions, 416 deletions
diff --git a/arch/arm/plat-samsung/pwm.c b/arch/arm/plat-samsung/pwm.c deleted file mode 100644 index d3583050fb05..000000000000 --- a/arch/arm/plat-samsung/pwm.c +++ /dev/null @@ -1,416 +0,0 @@ -/* arch/arm/plat-s3c/pwm.c - * - * Copyright (c) 2007 Ben Dooks - * Copyright (c) 2008 Simtec Electronics - * Ben Dooks <ben@simtec.co.uk>, <ben-linux@fluff.org> - * - * S3C series PWM device core - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License. -*/ - -#include <linux/export.h> -#include <linux/kernel.h> -#include <linux/platform_device.h> -#include <linux/slab.h> -#include <linux/err.h> -#include <linux/clk.h> -#include <linux/io.h> -#include <linux/pwm.h> - -#include <mach/map.h> - -#include <plat/regs-timer.h> - -struct pwm_device { - struct list_head list; - struct platform_device *pdev; - - struct clk *clk_div; - struct clk *clk; - const char *label; - - unsigned int period_ns; - unsigned int duty_ns; - - unsigned char tcon_base; - unsigned char use_count; - unsigned char pwm_id; -}; - -#define pwm_dbg(_pwm, msg...) dev_dbg(&(_pwm)->pdev->dev, msg) - -static struct clk *clk_scaler[2]; - -static inline int pwm_is_tdiv(struct pwm_device *pwm) -{ - return clk_get_parent(pwm->clk) == pwm->clk_div; -} - -static DEFINE_MUTEX(pwm_lock); -static LIST_HEAD(pwm_list); - -struct pwm_device *pwm_request(int pwm_id, const char *label) -{ - struct pwm_device *pwm; - int found = 0; - - mutex_lock(&pwm_lock); - - list_for_each_entry(pwm, &pwm_list, list) { - if (pwm->pwm_id == pwm_id) { - found = 1; - break; - } - } - - if (found) { - if (pwm->use_count == 0) { - pwm->use_count = 1; - pwm->label = label; - } else - pwm = ERR_PTR(-EBUSY); - } else - pwm = ERR_PTR(-ENOENT); - - mutex_unlock(&pwm_lock); - return pwm; -} - -EXPORT_SYMBOL(pwm_request); - - -void pwm_free(struct pwm_device *pwm) -{ - mutex_lock(&pwm_lock); - - if (pwm->use_count) { - pwm->use_count--; - pwm->label = NULL; - } else - printk(KERN_ERR "PWM%d device already freed\n", pwm->pwm_id); - - mutex_unlock(&pwm_lock); -} - -EXPORT_SYMBOL(pwm_free); - -#define pwm_tcon_start(pwm) (1 << (pwm->tcon_base + 0)) -#define pwm_tcon_invert(pwm) (1 << (pwm->tcon_base + 2)) -#define pwm_tcon_autoreload(pwm) (1 << (pwm->tcon_base + 3)) -#define pwm_tcon_manulupdate(pwm) (1 << (pwm->tcon_base + 1)) - -int pwm_enable(struct pwm_device *pwm) -{ - unsigned long flags; - unsigned long tcon; - - local_irq_save(flags); - - tcon = __raw_readl(S3C2410_TCON); - tcon |= pwm_tcon_start(pwm); - __raw_writel(tcon, S3C2410_TCON); - - local_irq_restore(flags); - - return 0; -} - -EXPORT_SYMBOL(pwm_enable); - -void pwm_disable(struct pwm_device *pwm) -{ - unsigned long flags; - unsigned long tcon; - - local_irq_save(flags); - - tcon = __raw_readl(S3C2410_TCON); - tcon &= ~pwm_tcon_start(pwm); - __raw_writel(tcon, S3C2410_TCON); - - local_irq_restore(flags); -} - -EXPORT_SYMBOL(pwm_disable); - -static unsigned long pwm_calc_tin(struct pwm_device *pwm, unsigned long freq) -{ - unsigned long tin_parent_rate; - unsigned int div; - - tin_parent_rate = clk_get_rate(clk_get_parent(pwm->clk_div)); - pwm_dbg(pwm, "tin parent at %lu\n", tin_parent_rate); - - for (div = 2; div <= 16; div *= 2) { - if ((tin_parent_rate / (div << 16)) < freq) - return tin_parent_rate / div; - } - - return tin_parent_rate / 16; -} - -#define NS_IN_HZ (1000000000UL) - -int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns) -{ - unsigned long tin_rate; - unsigned long tin_ns; - unsigned long period; - unsigned long flags; - unsigned long tcon; - unsigned long tcnt; - long tcmp; - - /* We currently avoid using 64bit arithmetic by using the - * fact that anything faster than 1Hz is easily representable - * by 32bits. */ - - if (period_ns > NS_IN_HZ || duty_ns > NS_IN_HZ) - return -ERANGE; - - if (duty_ns > period_ns) - return -EINVAL; - - if (period_ns == pwm->period_ns && - duty_ns == pwm->duty_ns) - return 0; - - /* The TCMP and TCNT can be read without a lock, they're not - * shared between the timers. */ - - tcmp = __raw_readl(S3C2410_TCMPB(pwm->pwm_id)); - tcnt = __raw_readl(S3C2410_TCNTB(pwm->pwm_id)); - - period = NS_IN_HZ / period_ns; - - pwm_dbg(pwm, "duty_ns=%d, period_ns=%d (%lu)\n", - duty_ns, period_ns, period); - - /* Check to see if we are changing the clock rate of the PWM */ - - if (pwm->period_ns != period_ns) { - if (pwm_is_tdiv(pwm)) { - tin_rate = pwm_calc_tin(pwm, period); - clk_set_rate(pwm->clk_div, tin_rate); - } else - tin_rate = clk_get_rate(pwm->clk); - - pwm->period_ns = period_ns; - - pwm_dbg(pwm, "tin_rate=%lu\n", tin_rate); - - tin_ns = NS_IN_HZ / tin_rate; - tcnt = period_ns / tin_ns; - } else - tin_ns = NS_IN_HZ / clk_get_rate(pwm->clk); - - /* Note, counters count down */ - - tcmp = duty_ns / tin_ns; - tcmp = tcnt - tcmp; - /* the pwm hw only checks the compare register after a decrement, - so the pin never toggles if tcmp = tcnt */ - if (tcmp == tcnt) - tcmp--; - - pwm_dbg(pwm, "tin_ns=%lu, tcmp=%ld/%lu\n", tin_ns, tcmp, tcnt); - - if (tcmp < 0) - tcmp = 0; - - /* Update the PWM register block. */ - - local_irq_save(flags); - - __raw_writel(tcmp, S3C2410_TCMPB(pwm->pwm_id)); - __raw_writel(tcnt, S3C2410_TCNTB(pwm->pwm_id)); - - tcon = __raw_readl(S3C2410_TCON); - tcon |= pwm_tcon_manulupdate(pwm); - tcon |= pwm_tcon_autoreload(pwm); - __raw_writel(tcon, S3C2410_TCON); - - tcon &= ~pwm_tcon_manulupdate(pwm); - __raw_writel(tcon, S3C2410_TCON); - - local_irq_restore(flags); - - return 0; -} - -EXPORT_SYMBOL(pwm_config); - -static int pwm_register(struct pwm_device *pwm) -{ - pwm->duty_ns = -1; - pwm->period_ns = -1; - - mutex_lock(&pwm_lock); - list_add_tail(&pwm->list, &pwm_list); - mutex_unlock(&pwm_lock); - - return 0; -} - -static int s3c_pwm_probe(struct platform_device *pdev) -{ - struct device *dev = &pdev->dev; - struct pwm_device *pwm; - unsigned long flags; - unsigned long tcon; - unsigned int id = pdev->id; - int ret; - - if (id == 4) { - dev_err(dev, "TIMER4 is currently not supported\n"); - return -ENXIO; - } - - pwm = kzalloc(sizeof(struct pwm_device), GFP_KERNEL); - if (pwm == NULL) { - dev_err(dev, "failed to allocate pwm_device\n"); - return -ENOMEM; - } - - pwm->pdev = pdev; - pwm->pwm_id = id; - - /* calculate base of control bits in TCON */ - pwm->tcon_base = id == 0 ? 0 : (id * 4) + 4; - - pwm->clk = clk_get(dev, "pwm-tin"); - if (IS_ERR(pwm->clk)) { - dev_err(dev, "failed to get pwm tin clk\n"); - ret = PTR_ERR(pwm->clk); - goto err_alloc; - } - - pwm->clk_div = clk_get(dev, "pwm-tdiv"); - if (IS_ERR(pwm->clk_div)) { - dev_err(dev, "failed to get pwm tdiv clk\n"); - ret = PTR_ERR(pwm->clk_div); - goto err_clk_tin; - } - - clk_enable(pwm->clk); - clk_enable(pwm->clk_div); - - local_irq_save(flags); - - tcon = __raw_readl(S3C2410_TCON); - tcon |= pwm_tcon_invert(pwm); - __raw_writel(tcon, S3C2410_TCON); - - local_irq_restore(flags); - - - ret = pwm_register(pwm); - if (ret) { - dev_err(dev, "failed to register pwm\n"); - goto err_clk_tdiv; - } - - pwm_dbg(pwm, "config bits %02x\n", - (__raw_readl(S3C2410_TCON) >> pwm->tcon_base) & 0x0f); - - dev_info(dev, "tin at %lu, tdiv at %lu, tin=%sclk, base %d\n", - clk_get_rate(pwm->clk), - clk_get_rate(pwm->clk_div), - pwm_is_tdiv(pwm) ? "div" : "ext", pwm->tcon_base); - - platform_set_drvdata(pdev, pwm); - return 0; - - err_clk_tdiv: - clk_disable(pwm->clk_div); - clk_disable(pwm->clk); - clk_put(pwm->clk_div); - - err_clk_tin: - clk_put(pwm->clk); - - err_alloc: - kfree(pwm); - return ret; -} - -static int __devexit s3c_pwm_remove(struct platform_device *pdev) -{ - struct pwm_device *pwm = platform_get_drvdata(pdev); - - clk_disable(pwm->clk_div); - clk_disable(pwm->clk); - clk_put(pwm->clk_div); - clk_put(pwm->clk); - kfree(pwm); - - return 0; -} - -#ifdef CONFIG_PM -static int s3c_pwm_suspend(struct platform_device *pdev, pm_message_t state) -{ - struct pwm_device *pwm = platform_get_drvdata(pdev); - - /* No one preserve these values during suspend so reset them - * Otherwise driver leaves PWM unconfigured if same values - * passed to pwm_config - */ - pwm->period_ns = 0; - pwm->duty_ns = 0; - - return 0; -} - -static int s3c_pwm_resume(struct platform_device *pdev) -{ - struct pwm_device *pwm = platform_get_drvdata(pdev); - unsigned long tcon; - - /* Restore invertion */ - tcon = __raw_readl(S3C2410_TCON); - tcon |= pwm_tcon_invert(pwm); - __raw_writel(tcon, S3C2410_TCON); - - return 0; -} - -#else -#define s3c_pwm_suspend NULL -#define s3c_pwm_resume NULL -#endif - -static struct platform_driver s3c_pwm_driver = { - .driver = { - .name = "s3c24xx-pwm", - .owner = THIS_MODULE, - }, - .probe = s3c_pwm_probe, - .remove = __devexit_p(s3c_pwm_remove), - .suspend = s3c_pwm_suspend, - .resume = s3c_pwm_resume, -}; - -static int __init pwm_init(void) -{ - int ret; - - clk_scaler[0] = clk_get(NULL, "pwm-scaler0"); - clk_scaler[1] = clk_get(NULL, "pwm-scaler1"); - - if (IS_ERR(clk_scaler[0]) || IS_ERR(clk_scaler[1])) { - printk(KERN_ERR "%s: failed to get scaler clocks\n", __func__); - return -EINVAL; - } - - ret = platform_driver_register(&s3c_pwm_driver); - if (ret) - printk(KERN_ERR "%s: failed to add pwm driver\n", __func__); - - return ret; -} - -arch_initcall(pwm_init); |