mirror of
https://github.com/torvalds/linux.git
synced 2024-11-08 21:21:47 +00:00
b50675dcc3
Signed-off-by: Axel Lin <axel.lin@gmail.com> Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
163 lines
3.2 KiB
C
163 lines
3.2 KiB
C
/*
|
|
* Blackfin Pulse Width Modulation (PWM) core
|
|
*
|
|
* Copyright (c) 2011 Analog Devices Inc.
|
|
*
|
|
* Licensed under the GPL-2 or later.
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/pwm.h>
|
|
#include <linux/slab.h>
|
|
|
|
#include <asm/gptimers.h>
|
|
#include <asm/portmux.h>
|
|
|
|
struct bfin_pwm_chip {
|
|
struct pwm_chip chip;
|
|
};
|
|
|
|
struct bfin_pwm {
|
|
unsigned short pin;
|
|
};
|
|
|
|
static const unsigned short pwm_to_gptimer_per[] = {
|
|
P_TMR0, P_TMR1, P_TMR2, P_TMR3, P_TMR4, P_TMR5,
|
|
P_TMR6, P_TMR7, P_TMR8, P_TMR9, P_TMR10, P_TMR11,
|
|
};
|
|
|
|
static int bfin_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
|
|
{
|
|
struct bfin_pwm *priv;
|
|
int ret;
|
|
|
|
if (pwm->hwpwm >= ARRAY_SIZE(pwm_to_gptimer_per))
|
|
return -EINVAL;
|
|
|
|
priv = kzalloc(sizeof(*priv), GFP_KERNEL);
|
|
if (!priv)
|
|
return -ENOMEM;
|
|
|
|
priv->pin = pwm_to_gptimer_per[pwm->hwpwm];
|
|
|
|
ret = peripheral_request(priv->pin, NULL);
|
|
if (ret) {
|
|
kfree(priv);
|
|
return ret;
|
|
}
|
|
|
|
pwm_set_chip_data(pwm, priv);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void bfin_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
|
|
{
|
|
struct bfin_pwm *priv = pwm_get_chip_data(pwm);
|
|
|
|
if (priv) {
|
|
peripheral_free(priv->pin);
|
|
kfree(priv);
|
|
}
|
|
}
|
|
|
|
static int bfin_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
|
|
int duty_ns, int period_ns)
|
|
{
|
|
struct bfin_pwm *priv = pwm_get_chip_data(pwm);
|
|
unsigned long period, duty;
|
|
unsigned long long val;
|
|
|
|
if (duty_ns < 0 || duty_ns > period_ns)
|
|
return -EINVAL;
|
|
|
|
val = (unsigned long long)get_sclk() * period_ns;
|
|
do_div(val, NSEC_PER_SEC);
|
|
period = val;
|
|
|
|
val = (unsigned long long)period * duty_ns;
|
|
do_div(val, period_ns);
|
|
duty = period - val;
|
|
|
|
if (duty >= period)
|
|
duty = period - 1;
|
|
|
|
set_gptimer_config(priv->pin, TIMER_MODE_PWM | TIMER_PERIOD_CNT);
|
|
set_gptimer_pwidth(priv->pin, duty);
|
|
set_gptimer_period(priv->pin, period);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int bfin_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
|
|
{
|
|
struct bfin_pwm *priv = pwm_get_chip_data(pwm);
|
|
|
|
enable_gptimer(priv->pin);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void bfin_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
|
|
{
|
|
struct bfin_pwm *priv = pwm_get_chip_data(pwm);
|
|
|
|
disable_gptimer(priv->pin);
|
|
}
|
|
|
|
static struct pwm_ops bfin_pwm_ops = {
|
|
.request = bfin_pwm_request,
|
|
.free = bfin_pwm_free,
|
|
.config = bfin_pwm_config,
|
|
.enable = bfin_pwm_enable,
|
|
.disable = bfin_pwm_disable,
|
|
.owner = THIS_MODULE,
|
|
};
|
|
|
|
static int bfin_pwm_probe(struct platform_device *pdev)
|
|
{
|
|
struct bfin_pwm_chip *pwm;
|
|
int ret;
|
|
|
|
pwm = devm_kzalloc(&pdev->dev, sizeof(*pwm), GFP_KERNEL);
|
|
if (!pwm) {
|
|
dev_err(&pdev->dev, "failed to allocate memory\n");
|
|
return -ENOMEM;
|
|
}
|
|
|
|
platform_set_drvdata(pdev, pwm);
|
|
|
|
pwm->chip.dev = &pdev->dev;
|
|
pwm->chip.ops = &bfin_pwm_ops;
|
|
pwm->chip.base = -1;
|
|
pwm->chip.npwm = 12;
|
|
|
|
ret = pwmchip_add(&pwm->chip);
|
|
if (ret < 0) {
|
|
dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
|
|
return ret;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int __devexit bfin_pwm_remove(struct platform_device *pdev)
|
|
{
|
|
struct bfin_pwm_chip *pwm = platform_get_drvdata(pdev);
|
|
|
|
return pwmchip_remove(&pwm->chip);
|
|
}
|
|
|
|
static struct platform_driver bfin_pwm_driver = {
|
|
.driver = {
|
|
.name = "bfin-pwm",
|
|
},
|
|
.probe = bfin_pwm_probe,
|
|
.remove = __devexit_p(bfin_pwm_remove),
|
|
};
|
|
|
|
module_platform_driver(bfin_pwm_driver);
|
|
|
|
MODULE_LICENSE("GPL");
|