diff options
Diffstat (limited to 'drivers/mfd/max7360.c')
| -rw-r--r-- | drivers/mfd/max7360.c | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/drivers/mfd/max7360.c b/drivers/mfd/max7360.c new file mode 100644 index 000000000000..5ee459c490ec --- /dev/null +++ b/drivers/mfd/max7360.c @@ -0,0 +1,171 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Maxim MAX7360 Core Driver + * + * Copyright 2025 Bootlin + * + * Authors: + * Kamel Bouhara <kamel.bouhara@bootlin.com> + * Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com> + */ + +#include <linux/array_size.h> +#include <linux/bits.h> +#include <linux/delay.h> +#include <linux/device/devres.h> +#include <linux/dev_printk.h> +#include <linux/err.h> +#include <linux/i2c.h> +#include <linux/interrupt.h> +#include <linux/mfd/core.h> +#include <linux/mfd/max7360.h> +#include <linux/mod_devicetable.h> +#include <linux/module.h> +#include <linux/regmap.h> +#include <linux/types.h> + +static const struct mfd_cell max7360_cells[] = { + { .name = "max7360-pinctrl" }, + { .name = "max7360-pwm" }, + { .name = "max7360-keypad" }, + { .name = "max7360-rotary" }, + { + .name = "max7360-gpo", + .of_compatible = "maxim,max7360-gpo", + }, + { + .name = "max7360-gpio", + .of_compatible = "maxim,max7360-gpio", + }, +}; + +static const struct regmap_range max7360_volatile_ranges[] = { + regmap_reg_range(MAX7360_REG_KEYFIFO, MAX7360_REG_KEYFIFO), + regmap_reg_range(MAX7360_REG_I2C_TIMEOUT, MAX7360_REG_RTR_CNT), +}; + +static const struct regmap_access_table max7360_volatile_table = { + .yes_ranges = max7360_volatile_ranges, + .n_yes_ranges = ARRAY_SIZE(max7360_volatile_ranges), +}; + +static const struct regmap_config max7360_regmap_config = { + .reg_bits = 8, + .val_bits = 8, + .max_register = MAX7360_REG_PWMCFG(MAX7360_PORT_PWM_COUNT - 1), + .volatile_table = &max7360_volatile_table, + .cache_type = REGCACHE_MAPLE, +}; + +static int max7360_mask_irqs(struct regmap *regmap) +{ + struct device *dev = regmap_get_device(regmap); + unsigned int val; + int ret; + + /* + * GPIO/PWM interrupts are not masked on reset: as the MAX7360 "INTI" + * interrupt line is shared between GPIOs and rotary encoder, this could + * result in repeated spurious interrupts on the rotary encoder driver + * if the GPIO driver is not loaded. Mask them now to avoid this + * situation. + */ + for (unsigned int i = 0; i < MAX7360_PORT_PWM_COUNT; i++) { + ret = regmap_write_bits(regmap, MAX7360_REG_PWMCFG(i), + MAX7360_PORT_CFG_INTERRUPT_MASK, + MAX7360_PORT_CFG_INTERRUPT_MASK); + if (ret) + return dev_err_probe(dev, ret, + "Failed to write MAX7360 port configuration\n"); + } + + /* Read GPIO in register, to ACK any pending IRQ. */ + ret = regmap_read(regmap, MAX7360_REG_GPIOIN, &val); + if (ret) + return dev_err_probe(dev, ret, "Failed to read GPIO values\n"); + + return 0; +} + +static int max7360_reset(struct regmap *regmap) +{ + struct device *dev = regmap_get_device(regmap); + int ret; + + ret = regmap_write(regmap, MAX7360_REG_GPIOCFG, MAX7360_GPIO_CFG_GPIO_RST); + if (ret) { + dev_err(dev, "Failed to reset GPIO configuration: %x\n", ret); + return ret; + } + + ret = regcache_drop_region(regmap, MAX7360_REG_GPIOCFG, MAX7360_REG_GPIO_LAST); + if (ret) { + dev_err(dev, "Failed to drop regmap cache: %x\n", ret); + return ret; + } + + ret = regmap_write(regmap, MAX7360_REG_SLEEP, 0); + if (ret) { + dev_err(dev, "Failed to reset autosleep configuration: %x\n", ret); + return ret; + } + + ret = regmap_write(regmap, MAX7360_REG_DEBOUNCE, 0); + if (ret) + dev_err(dev, "Failed to reset GPO port count: %x\n", ret); + + return ret; +} + +static int max7360_probe(struct i2c_client *client) +{ + struct device *dev = &client->dev; + struct regmap *regmap; + int ret; + + regmap = devm_regmap_init_i2c(client, &max7360_regmap_config); + if (IS_ERR(regmap)) + return dev_err_probe(dev, PTR_ERR(regmap), "Failed to initialise regmap\n"); + + ret = max7360_reset(regmap); + if (ret) + return dev_err_probe(dev, ret, "Failed to reset device\n"); + + /* Get the device out of shutdown mode. */ + ret = regmap_write_bits(regmap, MAX7360_REG_GPIOCFG, + MAX7360_GPIO_CFG_GPIO_EN, + MAX7360_GPIO_CFG_GPIO_EN); + if (ret) + return dev_err_probe(dev, ret, "Failed to enable GPIO and PWM module\n"); + + ret = max7360_mask_irqs(regmap); + if (ret) + return dev_err_probe(dev, ret, "Could not mask interrupts\n"); + + ret = devm_mfd_add_devices(dev, PLATFORM_DEVID_NONE, + max7360_cells, ARRAY_SIZE(max7360_cells), + NULL, 0, NULL); + if (ret) + return dev_err_probe(dev, ret, "Failed to register child devices\n"); + + return 0; +} + +static const struct of_device_id max7360_dt_match[] = { + { .compatible = "maxim,max7360" }, + {} +}; +MODULE_DEVICE_TABLE(of, max7360_dt_match); + +static struct i2c_driver max7360_driver = { + .driver = { + .name = "max7360", + .of_match_table = max7360_dt_match, + }, + .probe = max7360_probe, +}; +module_i2c_driver(max7360_driver); + +MODULE_DESCRIPTION("Maxim MAX7360 I2C IO Expander core driver"); +MODULE_AUTHOR("Kamel Bouhara <kamel.bouhara@bootlin.com>"); +MODULE_LICENSE("GPL"); |