diff options
Diffstat (limited to 'drivers/pwm/pwm-adp5585.c')
| -rw-r--r-- | drivers/pwm/pwm-adp5585.c | 188 |
1 files changed, 188 insertions, 0 deletions
diff --git a/drivers/pwm/pwm-adp5585.c b/drivers/pwm/pwm-adp5585.c new file mode 100644 index 000000000000..40472ac5db64 --- /dev/null +++ b/drivers/pwm/pwm-adp5585.c @@ -0,0 +1,188 @@ +// 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/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"); |