From: Kamel Bouhara <kamel.bouhara@xxxxxxxxxxx> Add driver for Maxim Integrated MAX7360 PWM controller, supporting up to 8 independent PWM outputs. Signed-off-by: Kamel Bouhara <kamel.bouhara@xxxxxxxxxxx> Co-developed-by: Mathieu Dubois-Briand <mathieu.dubois-briand@xxxxxxxxxxx> Signed-off-by: Mathieu Dubois-Briand <mathieu.dubois-briand@xxxxxxxxxxx> Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> --- drivers/pwm/Kconfig | 10 +++ drivers/pwm/Makefile | 1 + drivers/pwm/pwm-max7360.c | 209 ++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 220 insertions(+) diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig index f00ce973dddf..f2b1ce47de7f 100644 --- a/drivers/pwm/Kconfig +++ b/drivers/pwm/Kconfig @@ -432,6 +432,16 @@ config PWM_LPSS_PLATFORM To compile this driver as a module, choose M here: the module will be called pwm-lpss-platform. +config PWM_MAX7360 + tristate "MAX7360 PWMs" + depends on MFD_MAX7360 + help + PWM driver for Maxim Integrated MAX7360 multifunction device, with + support for up to 8 PWM outputs. + + To compile this driver as a module, choose M here: the module + will be called pwm-max7360. + config PWM_MC33XS2410 tristate "MC33XS2410 PWM support" depends on OF diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile index ff4f47e5fb7a..dfa8b4966ee1 100644 --- a/drivers/pwm/Makefile +++ b/drivers/pwm/Makefile @@ -38,6 +38,7 @@ obj-$(CONFIG_PWM_LPC32XX) += pwm-lpc32xx.o obj-$(CONFIG_PWM_LPSS) += pwm-lpss.o obj-$(CONFIG_PWM_LPSS_PCI) += pwm-lpss-pci.o obj-$(CONFIG_PWM_LPSS_PLATFORM) += pwm-lpss-platform.o +obj-$(CONFIG_PWM_MAX7360) += pwm-max7360.o obj-$(CONFIG_PWM_MC33XS2410) += pwm-mc33xs2410.o obj-$(CONFIG_PWM_MEDIATEK) += pwm-mediatek.o obj-$(CONFIG_PWM_MESON) += pwm-meson.o diff --git a/drivers/pwm/pwm-max7360.c b/drivers/pwm/pwm-max7360.c new file mode 100644 index 000000000000..ebf93a7aee5b --- /dev/null +++ b/drivers/pwm/pwm-max7360.c @@ -0,0 +1,209 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright 2025 Bootlin + * + * Author: Kamel BOUHARA <kamel.bouhara@xxxxxxxxxxx> + * Author: Mathieu Dubois-Briand <mathieu.dubois-briand@xxxxxxxxxxx> + * + * PWM functionality of the MAX7360 multi-function device. + * https://www.analog.com/media/en/technical-documentation/data-sheets/MAX7360.pdf + * + * Limitations: + * - Only supports normal polarity. + * - The period is fixed to 2 ms. + * - Only the duty cycle can be changed, new values are applied at the beginning + * of the next cycle. + * - When disabled, the output is put in Hi-Z immediately. + */ +#include <linux/bits.h> +#include <linux/dev_printk.h> +#include <linux/err.h> +#include <linux/math64.h> +#include <linux/mfd/max7360.h> +#include <linux/minmax.h> +#include <linux/mod_devicetable.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 MAX7360_NUM_PWMS 8 +#define MAX7360_PWM_MAX 255 +#define MAX7360_PWM_STEPS 256 +#define MAX7360_PWM_PERIOD_NS (2 * NSEC_PER_MSEC) + +struct max7360_pwm_waveform { + u8 duty_steps; + bool enabled; +}; + +static int max7360_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct regmap *regmap = pwmchip_get_drvdata(chip); + + /* + * Make sure we use the individual PWM configuration register and not + * the global one. + * We never need to use the global one, so there is no need to revert + * that in the .free() callback. + */ + return regmap_write_bits(regmap, MAX7360_REG_PWMCFG(pwm->hwpwm), + MAX7360_PORT_CFG_COMMON_PWM, 0); +} + +static int max7360_pwm_round_waveform_tohw(struct pwm_chip *chip, + struct pwm_device *pwm, + const struct pwm_waveform *wf, + void *_wfhw) +{ + struct max7360_pwm_waveform *wfhw = _wfhw; + u64 duty_steps; + + /* + * Ignore user provided values for period_length_ns and duty_offset_ns: + * we only support fixed period of MAX7360_PWM_PERIOD_NS and offset of 0. + * Values from 0 to 254 as duty_steps will provide duty cycles of 0/256 + * to 254/256, while value 255 will provide a duty cycle of 100%. + */ + if (wf->duty_length_ns >= MAX7360_PWM_PERIOD_NS) { + duty_steps = MAX7360_PWM_MAX; + } else { + duty_steps = (u32)wf->duty_length_ns * MAX7360_PWM_STEPS / MAX7360_PWM_PERIOD_NS; + if (duty_steps == MAX7360_PWM_MAX) + duty_steps = MAX7360_PWM_MAX - 1; + } + + wfhw->duty_steps = min(MAX7360_PWM_MAX, duty_steps); + wfhw->enabled = !!wf->period_length_ns; + + if (wf->period_length_ns && wf->period_length_ns < MAX7360_PWM_PERIOD_NS) + return 1; + else + return 0; +} + +static int max7360_pwm_round_waveform_fromhw(struct pwm_chip *chip, struct pwm_device *pwm, + const void *_wfhw, struct pwm_waveform *wf) +{ + const struct max7360_pwm_waveform *wfhw = _wfhw; + + wf->period_length_ns = wfhw->enabled ? MAX7360_PWM_PERIOD_NS : 0; + wf->duty_offset_ns = 0; + + if (wfhw->enabled) { + if (wfhw->duty_steps == MAX7360_PWM_MAX) + wf->duty_length_ns = MAX7360_PWM_PERIOD_NS; + else + wf->duty_length_ns = DIV_ROUND_UP(wfhw->duty_steps * MAX7360_PWM_PERIOD_NS, + MAX7360_PWM_STEPS); + } else { + wf->duty_length_ns = 0; + } + + return 0; +} + +static int max7360_pwm_write_waveform(struct pwm_chip *chip, + struct pwm_device *pwm, + const void *_wfhw) +{ + struct regmap *regmap = pwmchip_get_drvdata(chip); + const struct max7360_pwm_waveform *wfhw = _wfhw; + unsigned int val; + int ret; + + if (wfhw->enabled) { + ret = regmap_write(regmap, MAX7360_REG_PWM(pwm->hwpwm), wfhw->duty_steps); + if (ret) + return ret; + } + + val = wfhw->enabled ? BIT(pwm->hwpwm) : 0; + return regmap_write_bits(regmap, MAX7360_REG_GPIOCTRL, BIT(pwm->hwpwm), val); +} + +static int max7360_pwm_read_waveform(struct pwm_chip *chip, + struct pwm_device *pwm, + void *_wfhw) +{ + struct regmap *regmap = pwmchip_get_drvdata(chip); + struct max7360_pwm_waveform *wfhw = _wfhw; + unsigned int val; + int ret; + + ret = regmap_read(regmap, MAX7360_REG_GPIOCTRL, &val); + if (ret) + return ret; + + if (val & BIT(pwm->hwpwm)) { + wfhw->enabled = true; + ret = regmap_read(regmap, MAX7360_REG_PWM(pwm->hwpwm), &val); + if (ret) + return ret; + + wfhw->duty_steps = val; + } else { + wfhw->enabled = false; + wfhw->duty_steps = 0; + } + + return 0; +} + +static const struct pwm_ops max7360_pwm_ops = { + .request = max7360_pwm_request, + .round_waveform_tohw = max7360_pwm_round_waveform_tohw, + .round_waveform_fromhw = max7360_pwm_round_waveform_fromhw, + .read_waveform = max7360_pwm_read_waveform, + .write_waveform = max7360_pwm_write_waveform, +}; + +static int max7360_pwm_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct pwm_chip *chip; + struct regmap *regmap; + int ret; + + regmap = dev_get_regmap(dev->parent, NULL); + if (!regmap) + return dev_err_probe(dev, -ENODEV, "Could not get parent regmap\n"); + + /* + * This MFD sub-device does not have any associated device tree node: + * properties are stored in the device node of the parent (MFD) device + * and this same node is used in phandles of client devices. + * Reuse this device tree node here, as otherwise the PWM subsystem + * would be confused by this topology. + */ + device_set_of_node_from_dev(dev, dev->parent); + + chip = devm_pwmchip_alloc(dev, MAX7360_NUM_PWMS, 0); + if (IS_ERR(chip)) + return PTR_ERR(chip); + chip->ops = &max7360_pwm_ops; + + pwmchip_set_drvdata(chip, regmap); + + ret = devm_pwmchip_add(dev, chip); + if (ret) + return dev_err_probe(dev, ret, "Failed to add PWM chip\n"); + + return 0; +} + +static struct platform_driver max7360_pwm_driver = { + .driver = { + .name = "max7360-pwm", + .probe_type = PROBE_PREFER_ASYNCHRONOUS, + }, + .probe = max7360_pwm_probe, +}; +module_platform_driver(max7360_pwm_driver); + +MODULE_DESCRIPTION("MAX7360 PWM driver"); +MODULE_AUTHOR("Kamel BOUHARA <kamel.bouhara@xxxxxxxxxxx>"); +MODULE_AUTHOR("Mathieu Dubois-Briand <mathieu.dubois-briand@xxxxxxxxxxx>"); +MODULE_LICENSE("GPL"); -- 2.39.5
