// SPDX-License-Identifier: GPL-2.0-only
/*
* Driver for TWL4030/6030 Pulse Width Modulator used as LED driver
*
* Copyright (C) 2012 Texas Instruments
* Author: Peter Ujfalusi <[email protected]>
*
* This driver is a complete rewrite of the former pwm-twl6030.c authorded by:
* Hemanth V <[email protected]>
*
* Reference manual for the twl6030 is available at:
* https://www.ti.com/lit/ds/symlink/twl6030.pdf
*
* Limitations:
* - The twl6030 hardware only supports two period lengths (128 clock ticks and
* 64 clock ticks), the driver only uses 128 ticks
* - The hardware doesn't support ON = 0, so the active part of a period doesn't
* start at its beginning.
* - The hardware could support inverted polarity (with a similar limitation as
* for normal: the last clock tick is always inactive).
* - The hardware emits a constant low output when disabled.
* - A request for .duty_cycle = 0 results in an output wave with one active
* clock tick per period. This should better use the disabled state.
* - The driver only implements setting the relative duty cycle.
* - The driver doesn't implement .get_state().
*/
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pwm.h>
#include <linux/mfd/twl.h>
#include <linux/slab.h>
/*
* This driver handles the PWM driven LED terminals of TWL4030 and TWL6030.
* To generate the signal on TWL4030:
* - LEDA uses PWMA
* - LEDB uses PWMB
* TWL6030 has one LED pin with dedicated LEDPWM
*/
#define TWL4030_LED_MAX 0x7f
#define TWL6030_LED_MAX 0xff
/* Registers, bits and macro for TWL4030 */
#define TWL4030_LEDEN_REG 0x00
#define TWL4030_PWMA_REG 0x01
#define TWL4030_LEDXON (1 << 0)
#define TWL4030_LEDXPWM (1 << 4)
#define TWL4030_LED_PINS (TWL4030_LEDXON | TWL4030_LEDXPWM)
#define TWL4030_LED_TOGGLE(led, x) ((x) << (led))
/* Register, bits and macro for TWL6030 */
#define TWL6030_LED_PWM_CTRL1 0xf4
#define TWL6030_LED_PWM_CTRL2 0xf5
#define TWL6040_LED_MODE_HW 0x00
#define TWL6040_LED_MODE_ON 0x01
#define TWL6040_LED_MODE_OFF 0x02
#define TWL6040_LED_MODE_MASK 0x03
struct twl_pwmled_chip {
struct mutex mutex;
};
static inline struct twl_pwmled_chip *to_twl(struct pwm_chip *chip)
{
return pwmchip_get_drvdata(chip);
}
static int twl4030_pwmled_config(struct pwm_chip *chip, struct pwm_device *pwm,
int duty_ns, int period_ns)
{
int duty_cycle = DIV_ROUND_UP(duty_ns * TWL4030_LED_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 > TWL4030_LED_MAX)
duty_cycle = 1;
base = pwm->hwpwm * 2 + TWL4030_PWMA_REG;
pwm_config[1] = duty_cycle;
ret = twl_i2c_write(TWL4030_MODULE_LED, pwm_config, base, 2);
if (ret < 0)
dev_err(pwmchip_parent(chip), "%s: Failed to configure PWM\n", pwm->label);
return ret;
}
static int twl4030_pwmled_enable(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct twl_pwmled_chip *twl = to_twl(chip);
int ret;
u8 val;
mutex_lock(&twl->mutex);
ret = twl_i2c_read_u8(TWL4030_MODULE_LED, &val, TWL4030_LEDEN_REG);
if (ret < 0) {
dev_err(pwmchip_parent(chip), "%s: Failed to read LEDEN\n", pwm->label);
goto out;
}
val |= TWL4030_LED_TOGGLE(pwm->hwpwm, TWL4030_LED_PINS);
ret = twl_i2c_write_u8(TWL4030_MODULE_LED, val, TWL4030_LEDEN_REG);
if (ret < 0)
dev_err(pwmchip_parent(chip), "%s: Failed to enable PWM\n", pwm->label);
out:
mutex_unlock(&twl->mutex);
return ret;
}
static void twl4030_pwmled_disable(struct pwm_chip *chip,
struct pwm_device *pwm)
{
struct twl_pwmled_chip *twl = to_twl(chip);
int ret;
u8 val;
mutex_lock(&twl->mutex);
ret = twl_i2c_read_u8(TWL4030_MODULE_LED, &val, TWL4030_LEDEN_REG);
if (ret < 0) {
dev_err(pwmchip_parent(chip), "%s: Failed to read LEDEN\n", pwm->label);
goto out;
}
val &= ~TWL4030_LED_TOGGLE(pwm->hwpwm, TWL4030_LED_PINS);
ret = twl_i2c_write_u8(TWL4030_MODULE_LED, val, TWL4030_LEDEN_REG);
if (ret < 0)
dev_err(pwmchip_parent(chip), "%s: Failed to disable PWM\n", pwm->label);
out:
mutex_unlock(&twl->mutex);
}
static int twl4030_pwmled_apply(struct pwm_chip *chip, struct pwm_device *pwm,
const struct pwm_state *state)
{
int ret;
if (state->polarity != PWM_POLARITY_NORMAL)
return -EINVAL;
if (!state->enabled) {
if (pwm->state.enabled)
twl4030_pwmled_disable(chip, pwm);
return 0;
}
/*
* We cannot skip calling ->config even if state->period ==
* pwm->state.period && state->duty_cycle == pwm->state.duty_cycle
* because we might have exited early in the last call to
* pwm_apply_might_sleep because of !state->enabled and so the two values in
* pwm->state might not be configured in hardware.
*/
ret = twl4030_pwmled_config(chip, pwm,
state->duty_cycle, state->period);
if (ret)
return ret;
if (!pwm->state.enabled)
ret = twl4030_pwmled_enable(chip, pwm);
return ret;
}
static const struct pwm_ops twl4030_pwmled_ops = {
.apply = twl4030_pwmled_apply,
};
static int twl6030_pwmled_config(struct pwm_chip *chip, struct pwm_device *pwm,
int duty_ns, int period_ns)
{
int duty_cycle = (duty_ns * TWL6030_LED_MAX) / period_ns;
u8 on_time;
int ret;
on_time = duty_cycle & 0xff;
ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, on_time,
TWL6030_LED_PWM_CTRL1);
if (ret < 0)
dev_err(pwmchip_parent(chip), "%s: Failed to configure PWM\n", pwm->label);
return ret;
}
static int twl6030_pwmled_enable(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct twl_pwmled_chip *twl = to_twl(chip);
int ret;
u8 val;
mutex_lock(&twl->mutex);
ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
if (ret < 0) {
dev_err(pwmchip_parent(chip), "%s: Failed to read PWM_CTRL2\n",
pwm->label);
goto out;
}
val &= ~TWL6040_LED_MODE_MASK;
val |= TWL6040_LED_MODE_ON;
ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
if (ret < 0)
dev_err(pwmchip_parent(chip), "%s: Failed to enable PWM\n", pwm->label);
out:
mutex_unlock(&twl->mutex);
return ret;
}
static void twl6030_pwmled_disable(struct pwm_chip *chip,
struct pwm_device *pwm)
{
struct twl_pwmled_chip *twl = to_twl(chip);
int ret;
u8 val;
mutex_lock(&twl->mutex);
ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
if (ret < 0) {
dev_err(pwmchip_parent(chip), "%s: Failed to read PWM_CTRL2\n",
pwm->label);
goto out;
}
val &= ~TWL6040_LED_MODE_MASK;
val |= TWL6040_LED_MODE_OFF;
ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
if (ret < 0)
dev_err(pwmchip_parent(chip), "%s: Failed to disable PWM\n", pwm->label);
out:
mutex_unlock(&twl->mutex);
}
static int twl6030_pwmled_apply(struct pwm_chip *chip, struct pwm_device *pwm,
const struct pwm_state *state)
{
int err;
if (state->polarity != pwm->state.polarity)
return -EINVAL;
if (!state->enabled) {
if (pwm->state.enabled)
twl6030_pwmled_disable(chip, pwm);
return 0;
}
err = twl6030_pwmled_config(chip, pwm,
state->duty_cycle, state->period);
if (err)
return err;
if (!pwm->state.enabled)
err = twl6030_pwmled_enable(chip, pwm);
return err;
}
static int twl6030_pwmled_request(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct twl_pwmled_chip *twl = to_twl(chip);
int ret;
u8 val;
mutex_lock(&twl->mutex);
ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
if (ret < 0) {
dev_err(pwmchip_parent(chip), "%s: Failed to read PWM_CTRL2\n",
pwm->label);
goto out;
}
val &= ~TWL6040_LED_MODE_MASK;
val |= TWL6040_LED_MODE_OFF;
ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
if (ret < 0)
dev_err(pwmchip_parent(chip), "%s: Failed to request PWM\n", pwm->label);
out:
mutex_unlock(&twl->mutex);
return ret;
}
static void twl6030_pwmled_free(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct twl_pwmled_chip *twl = to_twl(chip);
int ret;
u8 val;
mutex_lock(&twl->mutex);
ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
if (ret < 0) {
dev_err(pwmchip_parent(chip), "%s: Failed to read PWM_CTRL2\n",
pwm->label);
goto out;
}
val &= ~TWL6040_LED_MODE_MASK;
val |= TWL6040_LED_MODE_HW;
ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
if (ret < 0)
dev_err(pwmchip_parent(chip), "%s: Failed to free PWM\n", pwm->label);
out:
mutex_unlock(&twl->mutex);
}
static const struct pwm_ops twl6030_pwmled_ops = {
.apply = twl6030_pwmled_apply,
.request = twl6030_pwmled_request,
.free = twl6030_pwmled_free,
};
static int twl_pwmled_probe(struct platform_device *pdev)
{
struct pwm_chip *chip;
struct twl_pwmled_chip *twl;
unsigned int npwm;
const struct pwm_ops *ops;
if (twl_class_is_4030()) {
ops = &twl4030_pwmled_ops;
npwm = 2;
} else {
ops = &twl6030_pwmled_ops;
npwm = 1;
}
chip = devm_pwmchip_alloc(&pdev->dev, npwm, sizeof(*twl));
if (IS_ERR(chip))
return PTR_ERR(chip);
twl = to_twl(chip);
chip->ops = ops;
mutex_init(&twl->mutex);
return devm_pwmchip_add(&pdev->dev, chip);
}
#ifdef CONFIG_OF
static const struct of_device_id twl_pwmled_of_match[] = {
{ .compatible = "ti,twl4030-pwmled" },
{ .compatible = "ti,twl6030-pwmled" },
{ },
};
MODULE_DEVICE_TABLE(of, twl_pwmled_of_match);
#endif
static struct platform_driver twl_pwmled_driver = {
.driver = {
.name = "twl-pwmled",
.of_match_table = of_match_ptr(twl_pwmled_of_match),
},
.probe = twl_pwmled_probe,
};
module_platform_driver(twl_pwmled_driver);
MODULE_AUTHOR("Peter Ujfalusi <[email protected]>");
MODULE_DESCRIPTION("PWM driver for TWL4030 and TWL6030 LED outputs");
MODULE_ALIAS("platform:twl-pwmled");
MODULE_LICENSE("GPL");
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