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yaml
---
r: 257886
b: refs/heads/master
c: 006669e
h: refs/heads/master
v: v3
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Mike Frysinger committed Jul 23, 2011
1 parent 3b4c8c6 commit 40b1a1d
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Showing 4 changed files with 112 additions and 1 deletion.
2 changes: 1 addition & 1 deletion [refs]
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@@ -1,2 +1,2 @@
---
refs/heads/master: e1b55965337e2c0cd26055ce446c506448c08e6d
refs/heads/master: 006669ec21d99e161015150ffedeeaeaad513c3b
10 changes: 10 additions & 0 deletions trunk/arch/blackfin/Kconfig
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Expand Up @@ -953,6 +953,16 @@ config BFIN_GPTIMERS
To compile this driver as a module, choose M here: the module
will be called gptimers.

config HAVE_PWM
tristate "Enable PWM API support"
depends on BFIN_GPTIMERS
help
Enable support for the Pulse Width Modulation framework (as
found in linux/pwm.h).

To compile this driver as a module, choose M here: the module
will be called pwm.

choice
prompt "Uncached DMA region"
default DMA_UNCACHED_1M
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1 change: 1 addition & 0 deletions trunk/arch/blackfin/kernel/Makefile
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Expand Up @@ -21,6 +21,7 @@ obj-$(CONFIG_FUNCTION_TRACER) += ftrace-entry.o
obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += ftrace.o
CFLAGS_REMOVE_ftrace.o = -pg

obj-$(CONFIG_HAVE_PWM) += pwm.o
obj-$(CONFIG_IPIPE) += ipipe.o
obj-$(CONFIG_BFIN_GPTIMERS) += gptimers.o
obj-$(CONFIG_CPLB_INFO) += cplbinfo.o
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100 changes: 100 additions & 0 deletions trunk/arch/blackfin/kernel/pwm.c
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@@ -0,0 +1,100 @@
/*
* 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);

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