From cc3d5529fd9c24bed1a08c8a32899d09257197c9 Mon Sep 17 00:00:00 2001 From: zhiayang <500236+zhiayang@users.noreply.github.com> Date: Fri, 30 Sep 2022 09:22:01 +0800 Subject: [PATCH] feat(drivers): Driver for MAX7318 GPIO expander (#1295) Add driver for max7318 i2c gpio expander Co-authored-by: Pete Johanson --- app/drivers/gpio/CMakeLists.txt | 3 +- app/drivers/gpio/Kconfig | 3 +- app/drivers/gpio/Kconfig.max7318 | 25 ++ app/drivers/gpio/gpio_max7318.c | 336 ++++++++++++++++++ .../dts/bindings/gpio/maxim,max7318.yaml | 29 ++ 5 files changed, 394 insertions(+), 2 deletions(-) create mode 100644 app/drivers/gpio/Kconfig.max7318 create mode 100644 app/drivers/gpio/gpio_max7318.c create mode 100644 app/drivers/zephyr/dts/bindings/gpio/maxim,max7318.yaml diff --git a/app/drivers/gpio/CMakeLists.txt b/app/drivers/gpio/CMakeLists.txt index 0df31ad5..f4378151 100644 --- a/app/drivers/gpio/CMakeLists.txt +++ b/app/drivers/gpio/CMakeLists.txt @@ -1,4 +1,4 @@ -# Copyright (c) 2020 The ZMK Contributors +# Copyright (c) 2022 The ZMK Contributors # SPDX-License-Identifier: MIT zephyr_library_named(zmk__drivers__gpio) @@ -6,3 +6,4 @@ zephyr_library_include_directories(${CMAKE_SOURCE_DIR}/include) zephyr_library_sources_ifdef(CONFIG_GPIO_595 gpio_595.c) zephyr_library_sources_ifdef(CONFIG_GPIO_MCP23017 gpio_mcp23017.c) +zephyr_library_sources_ifdef(CONFIG_GPIO_MAX7318 gpio_max7318.c) diff --git a/app/drivers/gpio/Kconfig b/app/drivers/gpio/Kconfig index e6f8bfb8..43c7c24e 100644 --- a/app/drivers/gpio/Kconfig +++ b/app/drivers/gpio/Kconfig @@ -2,4 +2,5 @@ menuconfig ZMK_DRIVERS_GPIO bool "GPIO" rsource "Kconfig.mcp23017" -rsource "Kconfig.595" \ No newline at end of file +rsource "Kconfig.max7318" +rsource "Kconfig.595" diff --git a/app/drivers/gpio/Kconfig.max7318 b/app/drivers/gpio/Kconfig.max7318 new file mode 100644 index 00000000..ded7f926 --- /dev/null +++ b/app/drivers/gpio/Kconfig.max7318 @@ -0,0 +1,25 @@ +# MAX7318 GPIO configuration options + +# Copyright (c) 2022 The ZMK Contributors +# SPDX-License-Identifier: MIT + +DT_COMPAT_MAXIM_MAX7318 := maxim,max7318 + +menuconfig GPIO_MAX7318 + bool "MAX7318 I2C-based GPIO chip" + default $(dt_compat_enabled,$(DT_COMPAT_MAXIM_MAX7318)) + depends on I2C + select HAS_DTS_GPIO + select ZMK_DRIVERS_GPIO + help + Enable driver for MAX7318 I2C-based GPIO chip. + +if GPIO_MAX7318 + +config GPIO_MAX7318_INIT_PRIORITY + int "Init priority" + default 75 + help + Device driver initialization priority. + +endif #GPIO_MAX7318 diff --git a/app/drivers/gpio/gpio_max7318.c b/app/drivers/gpio/gpio_max7318.c new file mode 100644 index 00000000..3dcc710c --- /dev/null +++ b/app/drivers/gpio/gpio_max7318.c @@ -0,0 +1,336 @@ +/* + * 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 + +#define LOG_LEVEL CONFIG_GPIO_LOG_LEVEL +#include + +LOG_MODULE_REGISTER(gpio_max7318); + +// Register definitions +#define REG_INPUT_PORTA 0x00 +#define REG_INPUT_PORTB 0x01 +#define REG_OUTPUT_PORTA 0x02 +#define REG_OUTPUT_PORTB 0x03 +#define REG_IPOL_PORTA 0x04 +#define REG_IPOL_PORTB 0x05 +#define REG_CONFIG_PORTA 0x06 +#define REG_CONFIG_PORTB 0x07 + +// Configuration data +struct max7318_config { + struct gpio_driver_config common; + + struct i2c_dt_spec i2c_bus; + uint8_t ngpios; +}; + +// Runtime driver data +struct max7318_drv_data { + // gpio_driver_data needs to be first + struct gpio_driver_config data; + + struct k_sem lock; + + struct { + uint16_t ipol; + uint16_t config; + uint16_t output; + } reg_cache; +}; + +/** + * @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) { + const struct max7318_config *config = dev->config; + + uint16_t data = 0; + int ret = i2c_burst_read_dt(&config->i2c_bus, 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) { + const struct max7318_config *config = dev->config; + + 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); + + return i2c_burst_write_dt(&config->i2c_bus, 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; + + if (!device_is_ready(config->i2c_bus.bus)) { + LOG_WRN("i2c bus not ready!"); + return -EINVAL; + } + + LOG_INF("device initialised at 0x%x", config->i2c_bus.addr); + + k_sem_init(&drv_data->lock, 1, 1); + return 0; +} + +#define GPIO_PORT_PIN_MASK_FROM_NGPIOS(ngpios) ((gpio_port_pins_t)(((uint64_t)1 << (ngpios)) - 1U)) + +#define GPIO_PORT_PIN_MASK_FROM_DT_INST(inst) \ + GPIO_PORT_PIN_MASK_FROM_NGPIOS(DT_INST_PROP(inst, ngpios)) + +#define MAX7318_INIT(inst) \ + static struct max7318_config max7318_##inst##_config = { \ + .common = {.port_pin_mask = GPIO_PORT_PIN_MASK_FROM_DT_INST(inst)}, \ + .i2c_bus = I2C_DT_SPEC_INST_GET(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) diff --git a/app/drivers/zephyr/dts/bindings/gpio/maxim,max7318.yaml b/app/drivers/zephyr/dts/bindings/gpio/maxim,max7318.yaml new file mode 100644 index 00000000..2db84bcd --- /dev/null +++ b/app/drivers/zephyr/dts/bindings/gpio/maxim,max7318.yaml @@ -0,0 +1,29 @@ +# +# Copyright (c) 2022 The ZMK Contributors +# +# SPDX-License-Identifier: MIT +# + +description: > + This is a representation of the Maxim MAX7318 I2C Gpio Expander. + +compatible: "maxim,max7318" + +include: [gpio-controller.yaml, i2c-device.yaml] + +properties: + label: + required: true + + "#gpio-cells": + const: 2 + + ngpios: + type: int + required: true + const: 16 + description: Number of gpios supported + +gpio-cells: + - pin + - flags