mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-29 23:24:11 +08:00
77f37917a6
CONFIG_HOTPLUG is going away as an option so __devexit is no longer needed. Signed-off-by: Bill Pemberton <wfp5p@virginia.edu> Acked-by: Thierry Reding <thierry.reding@avionic-design.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
149 lines
3.5 KiB
C
149 lines
3.5 KiB
C
/*
|
|
* Copyright 2012 Alexandre Pereira da Silva <aletes.xgr@gmail.com>
|
|
*
|
|
* 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; version 2.
|
|
*
|
|
*/
|
|
|
|
#include <linux/clk.h>
|
|
#include <linux/err.h>
|
|
#include <linux/io.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/of.h>
|
|
#include <linux/of_address.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/pwm.h>
|
|
#include <linux/slab.h>
|
|
|
|
struct lpc32xx_pwm_chip {
|
|
struct pwm_chip chip;
|
|
struct clk *clk;
|
|
void __iomem *base;
|
|
};
|
|
|
|
#define PWM_ENABLE (1 << 31)
|
|
#define PWM_RELOADV(x) (((x) & 0xFF) << 8)
|
|
#define PWM_DUTY(x) ((x) & 0xFF)
|
|
|
|
#define to_lpc32xx_pwm_chip(_chip) \
|
|
container_of(_chip, struct lpc32xx_pwm_chip, chip)
|
|
|
|
static int lpc32xx_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
|
|
int duty_ns, int period_ns)
|
|
{
|
|
struct lpc32xx_pwm_chip *lpc32xx = to_lpc32xx_pwm_chip(chip);
|
|
unsigned long long c;
|
|
int period_cycles, duty_cycles;
|
|
|
|
c = clk_get_rate(lpc32xx->clk) / 256;
|
|
c = c * period_ns;
|
|
do_div(c, NSEC_PER_SEC);
|
|
|
|
/* Handle high and low extremes */
|
|
if (c == 0)
|
|
c = 1;
|
|
if (c > 255)
|
|
c = 0; /* 0 set division by 256 */
|
|
period_cycles = c;
|
|
|
|
c = 256 * duty_ns;
|
|
do_div(c, period_ns);
|
|
duty_cycles = c;
|
|
|
|
writel(PWM_ENABLE | PWM_RELOADV(period_cycles) | PWM_DUTY(duty_cycles),
|
|
lpc32xx->base + (pwm->hwpwm << 2));
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int lpc32xx_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
|
|
{
|
|
struct lpc32xx_pwm_chip *lpc32xx = to_lpc32xx_pwm_chip(chip);
|
|
|
|
return clk_enable(lpc32xx->clk);
|
|
}
|
|
|
|
static void lpc32xx_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
|
|
{
|
|
struct lpc32xx_pwm_chip *lpc32xx = to_lpc32xx_pwm_chip(chip);
|
|
|
|
writel(0, lpc32xx->base + (pwm->hwpwm << 2));
|
|
clk_disable(lpc32xx->clk);
|
|
}
|
|
|
|
static const struct pwm_ops lpc32xx_pwm_ops = {
|
|
.config = lpc32xx_pwm_config,
|
|
.enable = lpc32xx_pwm_enable,
|
|
.disable = lpc32xx_pwm_disable,
|
|
.owner = THIS_MODULE,
|
|
};
|
|
|
|
static int lpc32xx_pwm_probe(struct platform_device *pdev)
|
|
{
|
|
struct lpc32xx_pwm_chip *lpc32xx;
|
|
struct resource *res;
|
|
int ret;
|
|
|
|
lpc32xx = devm_kzalloc(&pdev->dev, sizeof(*lpc32xx), GFP_KERNEL);
|
|
if (!lpc32xx)
|
|
return -ENOMEM;
|
|
|
|
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
|
|
if (!res)
|
|
return -EINVAL;
|
|
|
|
lpc32xx->base = devm_request_and_ioremap(&pdev->dev, res);
|
|
if (!lpc32xx->base)
|
|
return -EADDRNOTAVAIL;
|
|
|
|
lpc32xx->clk = devm_clk_get(&pdev->dev, NULL);
|
|
if (IS_ERR(lpc32xx->clk))
|
|
return PTR_ERR(lpc32xx->clk);
|
|
|
|
lpc32xx->chip.dev = &pdev->dev;
|
|
lpc32xx->chip.ops = &lpc32xx_pwm_ops;
|
|
lpc32xx->chip.npwm = 2;
|
|
|
|
ret = pwmchip_add(&lpc32xx->chip);
|
|
if (ret < 0) {
|
|
dev_err(&pdev->dev, "failed to add PWM chip, error %d\n", ret);
|
|
return ret;
|
|
}
|
|
|
|
platform_set_drvdata(pdev, lpc32xx);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int lpc32xx_pwm_remove(struct platform_device *pdev)
|
|
{
|
|
struct lpc32xx_pwm_chip *lpc32xx = platform_get_drvdata(pdev);
|
|
|
|
clk_disable(lpc32xx->clk);
|
|
return pwmchip_remove(&lpc32xx->chip);
|
|
}
|
|
|
|
static struct of_device_id lpc32xx_pwm_dt_ids[] = {
|
|
{ .compatible = "nxp,lpc3220-pwm", },
|
|
{ /* sentinel */ }
|
|
};
|
|
MODULE_DEVICE_TABLE(of, lpc32xx_pwm_dt_ids);
|
|
|
|
static struct platform_driver lpc32xx_pwm_driver = {
|
|
.driver = {
|
|
.name = "lpc32xx-pwm",
|
|
.of_match_table = of_match_ptr(lpc32xx_pwm_dt_ids),
|
|
},
|
|
.probe = lpc32xx_pwm_probe,
|
|
.remove = lpc32xx_pwm_remove,
|
|
};
|
|
module_platform_driver(lpc32xx_pwm_driver);
|
|
|
|
MODULE_ALIAS("platform:lpc32xx-pwm");
|
|
MODULE_AUTHOR("Alexandre Pereira da Silva <aletes.xgr@gmail.com>");
|
|
MODULE_DESCRIPTION("LPC32XX PWM Driver");
|
|
MODULE_LICENSE("GPL v2");
|