006669ec21
For now, this only supports gptimers. Support for dedicated PWM devices as found on newer parts to come. Signed-off-by: Michael Hennerich <michael.hennerich@analog.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org>
101 lines
1.9 KiB
C
101 lines
1.9 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/pwm.h>
|
|
#include <linux/slab.h>
|
|
|
|
#include <asm/gptimers.h>
|
|
#include <asm/portmux.h>
|
|
|
|
struct pwm_device {
|
|
unsigned id;
|
|
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,
|
|
};
|
|
|
|
struct pwm_device *pwm_request(int pwm_id, const char *label)
|
|
{
|
|
struct pwm_device *pwm;
|
|
int ret;
|
|
|
|
/* XXX: pwm_id really should be unsigned */
|
|
if (pwm_id < 0)
|
|
return NULL;
|
|
|
|
pwm = kzalloc(sizeof(*pwm), GFP_KERNEL);
|
|
if (!pwm)
|
|
return pwm;
|
|
|
|
pwm->id = pwm_id;
|
|
if (pwm->id >= ARRAY_SIZE(pwm_to_gptimer_per))
|
|
goto err;
|
|
|
|
pwm->pin = pwm_to_gptimer_per[pwm->id];
|
|
ret = peripheral_request(pwm->pin, label);
|
|
if (ret)
|
|
goto err;
|
|
|
|
return pwm;
|
|
err:
|
|
kfree(pwm);
|
|
return NULL;
|
|
}
|
|
EXPORT_SYMBOL(pwm_request);
|
|
|
|
void pwm_free(struct pwm_device *pwm)
|
|
{
|
|
peripheral_free(pwm->pin);
|
|
kfree(pwm);
|
|
}
|
|
EXPORT_SYMBOL(pwm_free);
|
|
|
|
int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
|
|
{
|
|
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(pwm->id, TIMER_MODE_PWM | TIMER_PERIOD_CNT);
|
|
set_gptimer_pwidth(pwm->id, duty);
|
|
set_gptimer_period(pwm->id, period);
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(pwm_config);
|
|
|
|
int pwm_enable(struct pwm_device *pwm)
|
|
{
|
|
enable_gptimer(pwm->id);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(pwm_enable);
|
|
|
|
void pwm_disable(struct pwm_device *pwm)
|
|
{
|
|
disable_gptimer(pwm->id);
|
|
}
|
|
EXPORT_SYMBOL(pwm_disable);
|