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linux/drivers/pwm/pwm-twl.c
Axel Lin 9c88669c2c pwm: twl: Really disable twl6030 PWMs 
Current twl6030_pwm_disable() implementation writes TWL6030_TOGGLE3_REG
twice, the second write sets TWL6030_PWMXEN bits so the PWM clock does
not disable.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2014-05-08 23:41:47 +02:00

353 lines
8.9 KiB
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/*
* Driver for TWL4030/6030 Generic Pulse Width Modulator
*
* Copyright (C) 2012 Texas Instruments
* Author: Peter Ujfalusi <peter.ujfalusi@ti.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pwm.h>
#include <linux/i2c/twl.h>
#include <linux/slab.h>
/*
* This driver handles the PWMs of TWL4030 and TWL6030.
* The TRM names for the PWMs on TWL4030 are: PWM0, PWM1
* TWL6030 also have two PWMs named in the TRM as PWM1, PWM2
*/
#define TWL_PWM_MAX 0x7f
/* Registers, bits and macro for TWL4030 */
#define TWL4030_GPBR1_REG 0x0c
#define TWL4030_PMBR1_REG 0x0d
/* GPBR1 register bits */
#define TWL4030_PWMXCLK_ENABLE (1 << 0)
#define TWL4030_PWMX_ENABLE (1 << 2)
#define TWL4030_PWMX_BITS (TWL4030_PWMX_ENABLE | TWL4030_PWMXCLK_ENABLE)
#define TWL4030_PWM_TOGGLE(pwm, x) ((x) << (pwm))
/* PMBR1 register bits */
#define TWL4030_GPIO6_PWM0_MUTE_MASK (0x03 << 2)
#define TWL4030_GPIO6_PWM0_MUTE_PWM0 (0x01 << 2)
#define TWL4030_GPIO7_VIBRASYNC_PWM1_MASK (0x03 << 4)
#define TWL4030_GPIO7_VIBRASYNC_PWM1_PWM1 (0x03 << 4)
/* Register, bits and macro for TWL6030 */
#define TWL6030_TOGGLE3_REG 0x92
#define TWL6030_PWMXR (1 << 0)
#define TWL6030_PWMXS (1 << 1)
#define TWL6030_PWMXEN (1 << 2)
#define TWL6030_PWM_TOGGLE(pwm, x) ((x) << (pwm * 3))
struct twl_pwm_chip {
struct pwm_chip chip;
struct mutex mutex;
u8 twl6030_toggle3;
u8 twl4030_pwm_mux;
};
static inline struct twl_pwm_chip *to_twl(struct pwm_chip *chip)
{
return container_of(chip, struct twl_pwm_chip, chip);
}
static int twl_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
int duty_ns, int period_ns)
{
int duty_cycle = DIV_ROUND_UP(duty_ns * TWL_PWM_MAX, period_ns) + 1;
u8 pwm_config[2] = { 1, 0 };
int base, ret;
/*
* To configure the duty period:
* On-cycle is set to 1 (the minimum allowed value)
* The off time of 0 is not configurable, so the mapping is:
* 0 -> off cycle = 2,
* 1 -> off cycle = 2,
* 2 -> off cycle = 3,
* 126 - > off cycle 127,
* 127 - > off cycle 1
* When on cycle == off cycle the PWM will be always on
*/
if (duty_cycle == 1)
duty_cycle = 2;
else if (duty_cycle > TWL_PWM_MAX)
duty_cycle = 1;
base = pwm->hwpwm * 3;
pwm_config[1] = duty_cycle;
ret = twl_i2c_write(TWL_MODULE_PWM, pwm_config, base, 2);
if (ret < 0)
dev_err(chip->dev, "%s: Failed to configure PWM\n", pwm->label);
return ret;
}
static int twl4030_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct twl_pwm_chip *twl = to_twl(chip);
int ret;
u8 val;
mutex_lock(&twl->mutex);
ret = twl_i2c_read_u8(TWL4030_MODULE_INTBR, &val, TWL4030_GPBR1_REG);
if (ret < 0) {
dev_err(chip->dev, "%s: Failed to read GPBR1\n", pwm->label);
goto out;
}
val |= TWL4030_PWM_TOGGLE(pwm->hwpwm, TWL4030_PWMXCLK_ENABLE);
ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_GPBR1_REG);
if (ret < 0)
dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label);
val |= TWL4030_PWM_TOGGLE(pwm->hwpwm, TWL4030_PWMX_ENABLE);
ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_GPBR1_REG);
if (ret < 0)
dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label);
out:
mutex_unlock(&twl->mutex);
return ret;
}
static void twl4030_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct twl_pwm_chip *twl = to_twl(chip);
int ret;
u8 val;
mutex_lock(&twl->mutex);
ret = twl_i2c_read_u8(TWL4030_MODULE_INTBR, &val, TWL4030_GPBR1_REG);
if (ret < 0) {
dev_err(chip->dev, "%s: Failed to read GPBR1\n", pwm->label);
goto out;
}
val &= ~TWL4030_PWM_TOGGLE(pwm->hwpwm, TWL4030_PWMX_ENABLE);
ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_GPBR1_REG);
if (ret < 0)
dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);
val &= ~TWL4030_PWM_TOGGLE(pwm->hwpwm, TWL4030_PWMXCLK_ENABLE);
ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_GPBR1_REG);
if (ret < 0)
dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);
out:
mutex_unlock(&twl->mutex);
}
static int twl4030_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct twl_pwm_chip *twl = to_twl(chip);
int ret;
u8 val, mask, bits;
if (pwm->hwpwm == 1) {
mask = TWL4030_GPIO7_VIBRASYNC_PWM1_MASK;
bits = TWL4030_GPIO7_VIBRASYNC_PWM1_PWM1;
} else {
mask = TWL4030_GPIO6_PWM0_MUTE_MASK;
bits = TWL4030_GPIO6_PWM0_MUTE_PWM0;
}
mutex_lock(&twl->mutex);
ret = twl_i2c_read_u8(TWL4030_MODULE_INTBR, &val, TWL4030_PMBR1_REG);
if (ret < 0) {
dev_err(chip->dev, "%s: Failed to read PMBR1\n", pwm->label);
goto out;
}
/* Save the current MUX configuration for the PWM */
twl->twl4030_pwm_mux &= ~mask;
twl->twl4030_pwm_mux |= (val & mask);
/* Select PWM functionality */
val &= ~mask;
val |= bits;
ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_PMBR1_REG);
if (ret < 0)
dev_err(chip->dev, "%s: Failed to request PWM\n", pwm->label);
out:
mutex_unlock(&twl->mutex);
return ret;
}
static void twl4030_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct twl_pwm_chip *twl = to_twl(chip);
int ret;
u8 val, mask;
if (pwm->hwpwm == 1)
mask = TWL4030_GPIO7_VIBRASYNC_PWM1_MASK;
else
mask = TWL4030_GPIO6_PWM0_MUTE_MASK;
mutex_lock(&twl->mutex);
ret = twl_i2c_read_u8(TWL4030_MODULE_INTBR, &val, TWL4030_PMBR1_REG);
if (ret < 0) {
dev_err(chip->dev, "%s: Failed to read PMBR1\n", pwm->label);
goto out;
}
/* Restore the MUX configuration for the PWM */
val &= ~mask;
val |= (twl->twl4030_pwm_mux & mask);
ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_PMBR1_REG);
if (ret < 0)
dev_err(chip->dev, "%s: Failed to free PWM\n", pwm->label);
out:
mutex_unlock(&twl->mutex);
}
static int twl6030_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct twl_pwm_chip *twl = to_twl(chip);
int ret;
u8 val;
mutex_lock(&twl->mutex);
val = twl->twl6030_toggle3;
val |= TWL6030_PWM_TOGGLE(pwm->hwpwm, TWL6030_PWMXS | TWL6030_PWMXEN);
val &= ~TWL6030_PWM_TOGGLE(pwm->hwpwm, TWL6030_PWMXR);
ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_TOGGLE3_REG);
if (ret < 0) {
dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label);
goto out;
}
twl->twl6030_toggle3 = val;
out:
mutex_unlock(&twl->mutex);
return ret;
}
static void twl6030_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct twl_pwm_chip *twl = to_twl(chip);
int ret;
u8 val;
mutex_lock(&twl->mutex);
val = twl->twl6030_toggle3;
val |= TWL6030_PWM_TOGGLE(pwm->hwpwm, TWL6030_PWMXR);
val &= ~TWL6030_PWM_TOGGLE(pwm->hwpwm, TWL6030_PWMXS | TWL6030_PWMXEN);
ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_TOGGLE3_REG);
if (ret < 0) {
dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);
goto out;
}
twl->twl6030_toggle3 = val;
out:
mutex_unlock(&twl->mutex);
}
static const struct pwm_ops twl4030_pwm_ops = {
.config = twl_pwm_config,
.enable = twl4030_pwm_enable,
.disable = twl4030_pwm_disable,
.request = twl4030_pwm_request,
.free = twl4030_pwm_free,
.owner = THIS_MODULE,
};
static const struct pwm_ops twl6030_pwm_ops = {
.config = twl_pwm_config,
.enable = twl6030_pwm_enable,
.disable = twl6030_pwm_disable,
.owner = THIS_MODULE,
};
static int twl_pwm_probe(struct platform_device *pdev)
{
struct twl_pwm_chip *twl;
int ret;
twl = devm_kzalloc(&pdev->dev, sizeof(*twl), GFP_KERNEL);
if (!twl)
return -ENOMEM;
if (twl_class_is_4030())
twl->chip.ops = &twl4030_pwm_ops;
else
twl->chip.ops = &twl6030_pwm_ops;
twl->chip.dev = &pdev->dev;
twl->chip.base = -1;
twl->chip.npwm = 2;
twl->chip.can_sleep = true;
mutex_init(&twl->mutex);
ret = pwmchip_add(&twl->chip);
if (ret < 0)
return ret;
platform_set_drvdata(pdev, twl);
return 0;
}
static int twl_pwm_remove(struct platform_device *pdev)
{
struct twl_pwm_chip *twl = platform_get_drvdata(pdev);
return pwmchip_remove(&twl->chip);
}
#ifdef CONFIG_OF
static const struct of_device_id twl_pwm_of_match[] = {
{ .compatible = "ti,twl4030-pwm" },
{ .compatible = "ti,twl6030-pwm" },
{ },
};
MODULE_DEVICE_TABLE(of, twl_pwm_of_match);
#endif
static struct platform_driver twl_pwm_driver = {
.driver = {
.name = "twl-pwm",
.of_match_table = of_match_ptr(twl_pwm_of_match),
},
.probe = twl_pwm_probe,
.remove = twl_pwm_remove,
};
module_platform_driver(twl_pwm_driver);
MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>");
MODULE_DESCRIPTION("PWM driver for TWL4030 and TWL6030");
MODULE_ALIAS("platform:twl-pwm");
MODULE_LICENSE("GPL");
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