+++ /dev/null
-/* drivers/pwm/pwm-samsung.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.
-*/
-
-#define pr_fmt(fmt) "pwm-samsung: " fmt
-
-#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 s3c_chip {
- 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 pwm_id;
- struct pwm_chip chip;
-};
-
-#define to_s3c_chip(chip) container_of(chip, struct s3c_chip, chip)
-
-#define pwm_dbg(_pwm, msg...) dev_dbg(&(_pwm)->pdev->dev, msg)
-
-static struct clk *clk_scaler[2];
-
-static inline int pwm_is_tdiv(struct s3c_chip *chip)
-{
- return clk_get_parent(chip->clk) == chip->clk_div;
-}
-
-#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))
-
-static int s3c_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
-{
- struct s3c_chip *s3c = to_s3c_chip(chip);
- unsigned long flags;
- unsigned long tcon;
-
- local_irq_save(flags);
-
- tcon = __raw_readl(S3C2410_TCON);
- tcon |= pwm_tcon_start(s3c);
- __raw_writel(tcon, S3C2410_TCON);
-
- local_irq_restore(flags);
-
- return 0;
-}
-
-static void s3c_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
-{
- struct s3c_chip *s3c = to_s3c_chip(chip);
- unsigned long flags;
- unsigned long tcon;
-
- local_irq_save(flags);
-
- tcon = __raw_readl(S3C2410_TCON);
- tcon &= ~pwm_tcon_start(s3c);
- __raw_writel(tcon, S3C2410_TCON);
-
- local_irq_restore(flags);
-}
-
-static unsigned long pwm_calc_tin(struct s3c_chip *s3c, unsigned long freq)
-{
- unsigned long tin_parent_rate;
- unsigned int div;
-
- tin_parent_rate = clk_get_rate(clk_get_parent(s3c->clk_div));
- pwm_dbg(s3c, "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)
-
-static int s3c_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
- int duty_ns, int period_ns)
-{
- struct s3c_chip *s3c = to_s3c_chip(chip);
- 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 (period_ns == s3c->period_ns &&
- duty_ns == s3c->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(s3c->pwm_id));
- tcnt = __raw_readl(S3C2410_TCNTB(s3c->pwm_id));
-
- period = NS_IN_HZ / period_ns;
-
- pwm_dbg(s3c, "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 (s3c->period_ns != period_ns) {
- if (pwm_is_tdiv(s3c)) {
- tin_rate = pwm_calc_tin(s3c, period);
- clk_set_rate(s3c->clk_div, tin_rate);
- } else
- tin_rate = clk_get_rate(s3c->clk);
-
- s3c->period_ns = period_ns;
-
- pwm_dbg(s3c, "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(s3c->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(s3c, "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(s3c->pwm_id));
- __raw_writel(tcnt, S3C2410_TCNTB(s3c->pwm_id));
-
- tcon = __raw_readl(S3C2410_TCON);
- tcon |= pwm_tcon_manulupdate(s3c);
- tcon |= pwm_tcon_autoreload(s3c);
- __raw_writel(tcon, S3C2410_TCON);
-
- tcon &= ~pwm_tcon_manulupdate(s3c);
- __raw_writel(tcon, S3C2410_TCON);
-
- local_irq_restore(flags);
-
- return 0;
-}
-
-static struct pwm_ops s3c_pwm_ops = {
- .enable = s3c_pwm_enable,
- .disable = s3c_pwm_disable,
- .config = s3c_pwm_config,
- .owner = THIS_MODULE,
-};
-
-static int s3c_pwm_probe(struct platform_device *pdev)
-{
- struct device *dev = &pdev->dev;
- struct s3c_chip *s3c;
- 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;
- }
-
- s3c = devm_kzalloc(&pdev->dev, sizeof(*s3c), GFP_KERNEL);
- if (s3c == NULL) {
- dev_err(dev, "failed to allocate pwm_device\n");
- return -ENOMEM;
- }
-
- /* calculate base of control bits in TCON */
- s3c->tcon_base = id == 0 ? 0 : (id * 4) + 4;
- s3c->pwm_id = id;
- s3c->chip.dev = &pdev->dev;
- s3c->chip.ops = &s3c_pwm_ops;
- s3c->chip.base = -1;
- s3c->chip.npwm = 1;
-
- s3c->clk = devm_clk_get(dev, "pwm-tin");
- if (IS_ERR(s3c->clk)) {
- dev_err(dev, "failed to get pwm tin clk\n");
- return PTR_ERR(s3c->clk);
- }
-
- s3c->clk_div = devm_clk_get(dev, "pwm-tdiv");
- if (IS_ERR(s3c->clk_div)) {
- dev_err(dev, "failed to get pwm tdiv clk\n");
- return PTR_ERR(s3c->clk_div);
- }
-
- clk_enable(s3c->clk);
- clk_enable(s3c->clk_div);
-
- local_irq_save(flags);
-
- tcon = __raw_readl(S3C2410_TCON);
- tcon |= pwm_tcon_invert(s3c);
- __raw_writel(tcon, S3C2410_TCON);
-
- local_irq_restore(flags);
-
- ret = pwmchip_add(&s3c->chip);
- if (ret < 0) {
- dev_err(dev, "failed to register pwm\n");
- goto err_clk_tdiv;
- }
-
- pwm_dbg(s3c, "config bits %02x\n",
- (__raw_readl(S3C2410_TCON) >> s3c->tcon_base) & 0x0f);
-
- dev_info(dev, "tin at %lu, tdiv at %lu, tin=%sclk, base %d\n",
- clk_get_rate(s3c->clk),
- clk_get_rate(s3c->clk_div),
- pwm_is_tdiv(s3c) ? "div" : "ext", s3c->tcon_base);
-
- platform_set_drvdata(pdev, s3c);
- return 0;
-
- err_clk_tdiv:
- clk_disable(s3c->clk_div);
- clk_disable(s3c->clk);
- return ret;
-}
-
-static int s3c_pwm_remove(struct platform_device *pdev)
-{
- struct s3c_chip *s3c = platform_get_drvdata(pdev);
- int err;
-
- err = pwmchip_remove(&s3c->chip);
- if (err < 0)
- return err;
-
- clk_disable(s3c->clk_div);
- clk_disable(s3c->clk);
-
- return 0;
-}
-
-#ifdef CONFIG_PM_SLEEP
-static int s3c_pwm_suspend(struct device *dev)
-{
- struct s3c_chip *s3c = dev_get_drvdata(dev);
-
- /* No one preserve these values during suspend so reset them
- * Otherwise driver leaves PWM unconfigured if same values
- * passed to pwm_config
- */
- s3c->period_ns = 0;
- s3c->duty_ns = 0;
-
- return 0;
-}
-
-static int s3c_pwm_resume(struct device *dev)
-{
- struct s3c_chip *s3c = dev_get_drvdata(dev);
- unsigned long tcon;
-
- /* Restore invertion */
- tcon = __raw_readl(S3C2410_TCON);
- tcon |= pwm_tcon_invert(s3c);
- __raw_writel(tcon, S3C2410_TCON);
-
- return 0;
-}
-#endif
-
-static SIMPLE_DEV_PM_OPS(s3c_pwm_pm_ops, s3c_pwm_suspend,
- s3c_pwm_resume);
-
-static struct platform_driver s3c_pwm_driver = {
- .driver = {
- .name = "s3c24xx-pwm",
- .owner = THIS_MODULE,
- .pm = &s3c_pwm_pm_ops,
- },
- .probe = s3c_pwm_probe,
- .remove = s3c_pwm_remove,
-};
-
-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])) {
- pr_err("failed to get scaler clocks\n");
- return -EINVAL;
- }
-
- ret = platform_driver_register(&s3c_pwm_driver);
- if (ret)
- pr_err("failed to add pwm driver\n");
-
- return ret;
-}
-
-arch_initcall(pwm_init);
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