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// SPDX-License-Identifier: GPL-2.0-only
/*
* Analog Devices ADP5585 PWM driver
*
* Copyright 2022 NXP
* Copyright 2024 Ideas on Board Oy
*
* Limitations:
* - The .apply() operation executes atomically, but may not wait for the
* period to complete (this is not documented and would need to be tested).
* - Disabling the PWM drives the output pin to a low level immediately.
* - The hardware can only generate normal polarity output.
*/
#include <asm/byteorder.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/math64.h>
#include <linux/mfd/adp5585.h>
#include <linux/minmax.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/platform_device.h>
#include <linux/pwm.h>
#include <linux/regmap.h>
#include <linux/time.h>
#include <linux/types.h>
#define ADP5585_PWM_CHAN_NUM 1
#define ADP5585_PWM_OSC_FREQ_HZ 1000000U
#define ADP5585_PWM_MIN_PERIOD_NS (2ULL * NSEC_PER_SEC / ADP5585_PWM_OSC_FREQ_HZ)
#define ADP5585_PWM_MAX_PERIOD_NS (2ULL * 0xffff * NSEC_PER_SEC / ADP5585_PWM_OSC_FREQ_HZ)
static int pwm_adp5585_request(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct regmap *regmap = pwmchip_get_drvdata(chip);
/* Configure the R3 pin as PWM output. */
return regmap_update_bits(regmap, ADP5585_PIN_CONFIG_C,
ADP5585_R3_EXTEND_CFG_MASK,
ADP5585_R3_EXTEND_CFG_PWM_OUT);
}
static void pwm_adp5585_free(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct regmap *regmap = pwmchip_get_drvdata(chip);
regmap_update_bits(regmap, ADP5585_PIN_CONFIG_C,
ADP5585_R3_EXTEND_CFG_MASK,
ADP5585_R3_EXTEND_CFG_GPIO4);
}
static int pwm_adp5585_apply(struct pwm_chip *chip,
struct pwm_device *pwm,
const struct pwm_state *state)
{
struct regmap *regmap = pwmchip_get_drvdata(chip);
u64 period, duty_cycle;
u32 on, off;
__le16 val;
int ret;
if (!state->enabled) {
regmap_clear_bits(regmap, ADP5585_GENERAL_CFG, ADP5585_OSC_EN);
regmap_clear_bits(regmap, ADP5585_PWM_CFG, ADP5585_PWM_EN);
return 0;
}
if (state->polarity != PWM_POLARITY_NORMAL)
return -EINVAL;
if (state->period < ADP5585_PWM_MIN_PERIOD_NS)
return -EINVAL;
period = min(state->period, ADP5585_PWM_MAX_PERIOD_NS);
duty_cycle = min(state->duty_cycle, period);
/*
* Compute the on and off time. As the internal oscillator frequency is
* 1MHz, the calculation can be simplified without loss of precision.
*/
on = div_u64(duty_cycle, NSEC_PER_SEC / ADP5585_PWM_OSC_FREQ_HZ);
off = div_u64(period, NSEC_PER_SEC / ADP5585_PWM_OSC_FREQ_HZ) - on;
val = cpu_to_le16(off);
ret = regmap_bulk_write(regmap, ADP5585_PWM_OFFT_LOW, &val, 2);
if (ret)
return ret;
val = cpu_to_le16(on);
ret = regmap_bulk_write(regmap, ADP5585_PWM_ONT_LOW, &val, 2);
if (ret)
return ret;
/* Enable PWM in continuous mode and no external AND'ing. */
ret = regmap_update_bits(regmap, ADP5585_PWM_CFG,
ADP5585_PWM_IN_AND | ADP5585_PWM_MODE |
ADP5585_PWM_EN, ADP5585_PWM_EN);
if (ret)
return ret;
ret = regmap_set_bits(regmap, ADP5585_GENERAL_CFG, ADP5585_OSC_EN);
if (ret)
return ret;
return regmap_set_bits(regmap, ADP5585_PWM_CFG, ADP5585_PWM_EN);
}
static int pwm_adp5585_get_state(struct pwm_chip *chip,
struct pwm_device *pwm,
struct pwm_state *state)
{
struct regmap *regmap = pwmchip_get_drvdata(chip);
unsigned int on, off;
unsigned int val;
__le16 on_off;
int ret;
ret = regmap_bulk_read(regmap, ADP5585_PWM_OFFT_LOW, &on_off, 2);
if (ret)
return ret;
off = le16_to_cpu(on_off);
ret = regmap_bulk_read(regmap, ADP5585_PWM_ONT_LOW, &on_off, 2);
if (ret)
return ret;
on = le16_to_cpu(on_off);
state->duty_cycle = on * (NSEC_PER_SEC / ADP5585_PWM_OSC_FREQ_HZ);
state->period = (on + off) * (NSEC_PER_SEC / ADP5585_PWM_OSC_FREQ_HZ);
state->polarity = PWM_POLARITY_NORMAL;
regmap_read(regmap, ADP5585_PWM_CFG, &val);
state->enabled = !!(val & ADP5585_PWM_EN);
return 0;
}
static const struct pwm_ops adp5585_pwm_ops = {
.request = pwm_adp5585_request,
.free = pwm_adp5585_free,
.apply = pwm_adp5585_apply,
.get_state = pwm_adp5585_get_state,
};
static int adp5585_pwm_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct adp5585_dev *adp5585 = dev_get_drvdata(dev->parent);
struct pwm_chip *chip;
int ret;
chip = devm_pwmchip_alloc(dev, ADP5585_PWM_CHAN_NUM, 0);
if (IS_ERR(chip))
return PTR_ERR(chip);
device_set_of_node_from_dev(dev, dev->parent);
pwmchip_set_drvdata(chip, adp5585->regmap);
chip->ops = &adp5585_pwm_ops;
ret = devm_pwmchip_add(dev, chip);
if (ret)
return dev_err_probe(dev, ret, "failed to add PWM chip\n");
return 0;
}
static const struct platform_device_id adp5585_pwm_id_table[] = {
{ "adp5585-pwm" },
{ /* Sentinel */ }
};
MODULE_DEVICE_TABLE(platform, adp5585_pwm_id_table);
static struct platform_driver adp5585_pwm_driver = {
.driver = {
.name = "adp5585-pwm",
},
.probe = adp5585_pwm_probe,
.id_table = adp5585_pwm_id_table,
};
module_platform_driver(adp5585_pwm_driver);
MODULE_AUTHOR("Xiaoning Wang <xiaoning.wang@nxp.com>");
MODULE_DESCRIPTION("ADP5585 PWM Driver");
MODULE_LICENSE("GPL");
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