blob: c3a3a9dfc6b4bba905538ad355bef4fb8709f9c5 [file] [log] [blame]
/*
* PWM Greybus driver.
*
* Copyright 2014 Google Inc.
* Copyright 2014 Linaro Ltd.
*
* Released under the GPLv2 only.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/pwm.h>
#include "greybus.h"
struct gb_pwm_chip {
struct gb_connection *connection;
u8 pwm_max; /* max pwm number */
struct pwm_chip chip;
struct pwm_chip *pwm;
};
#define pwm_chip_to_gb_pwm_chip(chip) \
container_of(chip, struct gb_pwm_chip, chip)
static int gb_pwm_count_operation(struct gb_pwm_chip *pwmc)
{
struct gb_pwm_count_response response;
int ret;
ret = gb_operation_sync(pwmc->connection, GB_PWM_TYPE_PWM_COUNT,
NULL, 0, &response, sizeof(response));
if (ret)
return ret;
pwmc->pwm_max = response.count;
return 0;
}
static int gb_pwm_activate_operation(struct gb_pwm_chip *pwmc,
u8 which)
{
struct gb_pwm_activate_request request;
if (which > pwmc->pwm_max)
return -EINVAL;
request.which = which;
return gb_operation_sync(pwmc->connection, GB_PWM_TYPE_ACTIVATE,
&request, sizeof(request), NULL, 0);
}
static int gb_pwm_deactivate_operation(struct gb_pwm_chip *pwmc,
u8 which)
{
struct gb_pwm_deactivate_request request;
if (which > pwmc->pwm_max)
return -EINVAL;
request.which = which;
return gb_operation_sync(pwmc->connection, GB_PWM_TYPE_DEACTIVATE,
&request, sizeof(request), NULL, 0);
}
static int gb_pwm_config_operation(struct gb_pwm_chip *pwmc,
u8 which, u32 duty, u32 period)
{
struct gb_pwm_config_request request;
if (which > pwmc->pwm_max)
return -EINVAL;
request.which = which;
request.duty = cpu_to_le32(duty);
request.period = cpu_to_le32(period);
return gb_operation_sync(pwmc->connection, GB_PWM_TYPE_CONFIG,
&request, sizeof(request), NULL, 0);
}
static int gb_pwm_set_polarity_operation(struct gb_pwm_chip *pwmc,
u8 which, u8 polarity)
{
struct gb_pwm_polarity_request request;
if (which > pwmc->pwm_max)
return -EINVAL;
request.which = which;
request.polarity = polarity;
return gb_operation_sync(pwmc->connection, GB_PWM_TYPE_POLARITY,
&request, sizeof(request), NULL, 0);
}
static int gb_pwm_enable_operation(struct gb_pwm_chip *pwmc,
u8 which)
{
struct gb_pwm_enable_request request;
if (which > pwmc->pwm_max)
return -EINVAL;
request.which = which;
return gb_operation_sync(pwmc->connection, GB_PWM_TYPE_ENABLE,
&request, sizeof(request), NULL, 0);
}
static int gb_pwm_disable_operation(struct gb_pwm_chip *pwmc,
u8 which)
{
struct gb_pwm_disable_request request;
if (which > pwmc->pwm_max)
return -EINVAL;
request.which = which;
return gb_operation_sync(pwmc->connection, GB_PWM_TYPE_DISABLE,
&request, sizeof(request), NULL, 0);
}
static int gb_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip);
return gb_pwm_activate_operation(pwmc, pwm->hwpwm);
};
static void gb_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip);
if (test_bit(PWMF_ENABLED, &pwm->flags))
dev_warn(chip->dev, "freeing PWM device without disabling\n");
gb_pwm_deactivate_operation(pwmc, pwm->hwpwm);
}
static int gb_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
int duty_ns, int period_ns)
{
struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip);
return gb_pwm_config_operation(pwmc, pwm->hwpwm, duty_ns, period_ns);
};
static int gb_pwm_set_polarity(struct pwm_chip *chip, struct pwm_device *pwm,
enum pwm_polarity polarity)
{
struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip);
return gb_pwm_set_polarity_operation(pwmc, pwm->hwpwm, polarity);
};
static int gb_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip);
return gb_pwm_enable_operation(pwmc, pwm->hwpwm);
};
static void gb_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip);
gb_pwm_disable_operation(pwmc, pwm->hwpwm);
};
static const struct pwm_ops gb_pwm_ops = {
.request = gb_pwm_request,
.free = gb_pwm_free,
.config = gb_pwm_config,
.set_polarity = gb_pwm_set_polarity,
.enable = gb_pwm_enable,
.disable = gb_pwm_disable,
.owner = THIS_MODULE,
};
static int gb_pwm_connection_init(struct gb_connection *connection)
{
struct gb_pwm_chip *pwmc;
struct pwm_chip *pwm;
int ret;
pwmc = kzalloc(sizeof(*pwmc), GFP_KERNEL);
if (!pwmc)
return -ENOMEM;
pwmc->connection = connection;
connection->private = pwmc;
/* Query number of pwms present */
ret = gb_pwm_count_operation(pwmc);
if (ret)
goto out_err;
pwm = &pwmc->chip;
pwm->dev = &connection->bundle->dev;
pwm->ops = &gb_pwm_ops;
pwm->base = -1; /* Allocate base dynamically */
pwm->npwm = pwmc->pwm_max + 1;
pwm->can_sleep = true; /* FIXME */
ret = pwmchip_add(pwm);
if (ret) {
dev_err(&connection->bundle->dev,
"failed to register PWM: %d\n", ret);
goto out_err;
}
return 0;
out_err:
kfree(pwmc);
return ret;
}
static void gb_pwm_connection_exit(struct gb_connection *connection)
{
struct gb_pwm_chip *pwmc = connection->private;
if (!pwmc)
return;
pwmchip_remove(&pwmc->chip);
/* kref_put(pwmc->connection) */
kfree(pwmc);
}
static struct gb_protocol pwm_protocol = {
.name = "pwm",
.id = GREYBUS_PROTOCOL_PWM,
.major = GB_PWM_VERSION_MAJOR,
.minor = GB_PWM_VERSION_MINOR,
.connection_init = gb_pwm_connection_init,
.connection_exit = gb_pwm_connection_exit,
.request_recv = NULL, /* no incoming requests */
};
gb_builtin_protocol_driver(pwm_protocol);