/* * Copyright (c) 2022 The ZMK Contributors * * SPDX-License-Identifier: MIT */ #define DT_DRV_COMPAT maxim_max7318 /** * @file Driver for MAX7318 I2C-based GPIO driver. */ #include #include #include #include #include #include #include #include #include "gpio_max7318.h" #define LOG_LEVEL CONFIG_GPIO_LOG_LEVEL #include LOG_MODULE_REGISTER(gpio_max7318); /** * @brief Read the value of two consecutive registers * * Read two consecutive bytes from the register at address `reg` and `reg + 1`, * typically reading from registers for port 0 and 1 simultaneously. * * @param dev The max7318 device. * @param reg Register to read (the PORT0 of the pair of registers). * @param buf Buffer to read data into. * * @return 0 if successful, failed otherwise. */ static int read_registers(const struct device *dev, uint8_t reg, uint16_t *buf) { struct max7318_drv_data *const drv_data = (struct max7318_drv_data *const)dev->data; uint16_t dev_addr = ((struct max7318_config *)dev->config)->device_addr; uint16_t data = 0; int ret = i2c_burst_read(drv_data->i2c, dev_addr, reg, (uint8_t *)&data, sizeof(data)); if (ret) { LOG_DBG("i2c_write_read FAIL %d\n", ret); return ret; } *buf = sys_le16_to_cpu(data); LOG_DBG("max7318: read: reg[0x%X] = 0x%X, reg[0x%X] = 0x%X", reg, (*buf & 0xFF), (reg + 1), (*buf >> 8)); return 0; } /** * @brief Write the value of two consecutive registers * * Write two consecutive bytes from the register at address `reg` and `reg + 1`, * typically to registers for port 0 and 1 simultaneously. * * @param dev The max7318 device. * @param reg Register to write (usually the register for PORT0). * @param value The value to write * * @return 0 if successful, failed otherwise. */ static int write_registers(const struct device *dev, uint8_t reg, uint16_t value) { struct max7318_drv_data *const drv_data = (struct max7318_drv_data *const)dev->data; LOG_DBG("max7318: write: reg[0x%X] = 0x%X, reg[0x%X] = 0x%X", reg, (value & 0xFF), (reg + 1), (value >> 8)); uint16_t data = sys_cpu_to_le16(value); uint16_t dev_addr = ((struct max7318_config *)dev->config)->device_addr; return i2c_burst_write(drv_data->i2c, dev_addr, reg, (uint8_t *)&data, sizeof(data)); } /** * @brief Setup the pin direction (input or output) * * @param dev The max7318 device. * @param pin The pin number. * @param flags Flags of pin or port. * * @return 0 if successful, failed otherwise */ static int set_pin_direction(const struct device *dev, uint32_t pin, int flags) { struct max7318_drv_data *const drv_data = (struct max7318_drv_data *const)dev->data; uint16_t *dir = &drv_data->reg_cache.config; uint16_t *output = &drv_data->reg_cache.output; /* The output register is 1=high, 0=low; the direction (config) register is 1=input, 0=output. */ if ((flags & GPIO_OUTPUT) != 0U) { if ((flags & GPIO_OUTPUT_INIT_HIGH) != 0U) { *output |= BIT(pin); } else if ((flags & GPIO_OUTPUT_INIT_LOW) != 0U) { *output &= ~BIT(pin); } *dir &= ~BIT(pin); } else { *dir |= BIT(pin); } int ret = write_registers(dev, REG_OUTPUT_PORTA, *output); if (ret != 0) { return ret; } return write_registers(dev, REG_CONFIG_PORTA, *dir); } /** * @brief Setup the pin pull up/pull down status. This function doesn't actually set any * registers, since the max7318 only supports a pullup, and it can't be controlled. * * @param dev The max7318 device. * @param pin The pin number * @param flags Flags of pin or port * * @return 0 if successful, failed otherwise */ static int set_pin_pull_direction(const struct device *dev, uint32_t pin, int flags) { // actually, this chip only supports pull-up, and it can't be disabled. // so, if we try to set anything else, return enotsup; we don't actually // need to set any registers. if ((flags & GPIO_PULL_DOWN) != 0U) { return -ENOTSUP; } return 0; } static int max7318_config(const struct device *dev, gpio_pin_t pin, gpio_flags_t flags) { struct max7318_drv_data *const drv_data = (struct max7318_drv_data *const)dev->data; /* Can't do I2C bus operations from an ISR */ if (k_is_in_isr()) { return -EWOULDBLOCK; } k_sem_take(&drv_data->lock, K_FOREVER); int ret = 0; if ((flags & GPIO_OPEN_DRAIN) != 0U) { ret = -ENOTSUP; goto done; }; ret = set_pin_direction(dev, pin, flags); if (ret != 0) { LOG_ERR("error setting pin direction (%d)", ret); goto done; } ret = set_pin_pull_direction(dev, pin, flags); if (ret != 0) { LOG_ERR("error setting pin pull up/down (%d)", ret); goto done; } done: k_sem_give(&drv_data->lock); return ret; } static int max7318_port_get_raw(const struct device *dev, uint32_t *value) { struct max7318_drv_data *const drv_data = (struct max7318_drv_data *const)dev->data; /* Can't do I2C bus operations from an ISR */ if (k_is_in_isr()) { return -EWOULDBLOCK; } k_sem_take(&drv_data->lock, K_FOREVER); uint16_t buf = 0; int ret = read_registers(dev, REG_INPUT_PORTA, &buf); if (ret != 0) { goto done; } *value = buf; done: k_sem_give(&drv_data->lock); return ret; } static int max7318_port_set_masked_raw(const struct device *dev, uint32_t mask, uint32_t value) { struct max7318_drv_data *const drv_data = (struct max7318_drv_data *const)dev->data; /* Can't do I2C bus operations from an ISR */ if (k_is_in_isr()) { return -EWOULDBLOCK; } k_sem_take(&drv_data->lock, K_FOREVER); uint16_t buf = drv_data->reg_cache.output; buf = (buf & ~mask) | (mask & value); int ret = write_registers(dev, REG_OUTPUT_PORTA, buf); if (ret == 0) { drv_data->reg_cache.output = buf; } k_sem_give(&drv_data->lock); return ret; } static int max7318_port_set_bits_raw(const struct device *dev, uint32_t mask) { return max7318_port_set_masked_raw(dev, mask, mask); } static int max7318_port_clear_bits_raw(const struct device *dev, uint32_t mask) { return max7318_port_set_masked_raw(dev, mask, 0); } static int max7318_port_toggle_bits(const struct device *dev, uint32_t mask) { struct max7318_drv_data *const drv_data = (struct max7318_drv_data *const)dev->data; /* Can't do I2C bus operations from an ISR */ if (k_is_in_isr()) { return -EWOULDBLOCK; } k_sem_take(&drv_data->lock, K_FOREVER); uint16_t buf = drv_data->reg_cache.output; buf ^= mask; int ret = write_registers(dev, REG_OUTPUT_PORTA, buf); if (ret == 0) { drv_data->reg_cache.output = buf; } k_sem_give(&drv_data->lock); return ret; } static int max7318_pin_interrupt_configure(const struct device *dev, gpio_pin_t pin, enum gpio_int_mode mode, enum gpio_int_trig trig) { return -ENOTSUP; } static const struct gpio_driver_api api_table = { .pin_configure = max7318_config, .port_get_raw = max7318_port_get_raw, .port_set_masked_raw = max7318_port_set_masked_raw, .port_set_bits_raw = max7318_port_set_bits_raw, .port_clear_bits_raw = max7318_port_clear_bits_raw, .port_toggle_bits = max7318_port_toggle_bits, .pin_interrupt_configure = max7318_pin_interrupt_configure, }; /** * @brief Initialisation function of MAX7318 * * @param dev Device struct * @return 0 if successful, failed otherwise. */ static int max7318_init(const struct device *dev) { const struct max7318_config *const config = dev->config; struct max7318_drv_data *const drv_data = (struct max7318_drv_data *const)dev->data; drv_data->i2c = device_get_binding((char *)config->i2c_dev_name); if (!drv_data->i2c) { LOG_DBG("Unable to get i2c device"); return -ENODEV; } if (!device_is_ready(drv_data->i2c)) { LOG_WRN("i2c bus not ready!"); return -EINVAL; } LOG_INF("device initialised at 0x%x (i2c=%s)", config->device_addr, config->i2c_dev_name); k_sem_init(&drv_data->lock, 1, 1); return 0; } #define MAX7318_INIT(inst) \ static struct max7318_config max7318_##inst##_config = { \ .i2c_dev_name = DT_INST_BUS_LABEL(inst), \ .device_addr = DT_INST_REG_ADDR(inst), \ }; \ \ static struct max7318_drv_data max7318_##inst##_drvdata = { \ /* Default for registers according to datasheet */ \ .reg_cache.ipol = 0x0, \ .reg_cache.config = 0xFFFF, \ .reg_cache.output = 0xFFFF, \ }; \ \ DEVICE_DT_INST_DEFINE(inst, max7318_init, NULL, &max7318_##inst##_drvdata, \ &max7318_##inst##_config, POST_KERNEL, \ CONFIG_GPIO_MAX7318_INIT_PRIORITY, &api_table); DT_INST_FOREACH_STATUS_OKAY(MAX7318_INIT)