550 lines
16 KiB
C
550 lines
16 KiB
C
/**
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* Copyright (c) 2023 Antmicro <www.antmicro.com>
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* SPDX-License-Identifier: Apache-2.0
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*/
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#define DT_DRV_COMPAT st_stmpe811
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#include <zephyr/kernel.h>
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#include <zephyr/drivers/gpio.h>
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#include <zephyr/drivers/i2c.h>
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#include <zephyr/input/input.h>
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#include <zephyr/input/input_touch.h>
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#include <zephyr/sys/byteorder.h>
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#include <zephyr/logging/log.h>
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LOG_MODULE_REGISTER(stmpe811, CONFIG_INPUT_LOG_LEVEL);
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#define CHIP_ID 0x0811U
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/* Touch Screen Pins definition */
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#define STMPE811_GPIO_PIN_4 BIT(4)
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#define STMPE811_GPIO_PIN_5 BIT(5)
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#define STMPE811_GPIO_PIN_6 BIT(6)
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#define STMPE811_GPIO_PIN_7 BIT(7)
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#define STMPE811_TOUCH_YD STMPE811_GPIO_PIN_7
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#define STMPE811_TOUCH_XD STMPE811_GPIO_PIN_6
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#define STMPE811_TOUCH_YU STMPE811_GPIO_PIN_5
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#define STMPE811_TOUCH_XU STMPE811_GPIO_PIN_4
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#define STMPE811_TOUCH_IO_ALL \
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(STMPE811_TOUCH_YD | STMPE811_TOUCH_XD | STMPE811_TOUCH_YU | STMPE811_TOUCH_XU)
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/* Registers */
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#define STMPE811_CHP_ID_LSB_REG 0x00U
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#define STMPE811_ADC_CTRL1_REG 0x20U
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#define STMPE811_ADC_CTRL2_REG 0x21U
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#define STMPE811_SYS_CTRL1_REG 0x03U
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#define STMPE811_SYS_CTRL2_REG 0x04U
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#define STMPE811_TSC_CFG_REG 0x41U
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#define STMPE811_IO_AF_REG 0x17U
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#define STMPE811_FIFO_TH_REG 0x4AU
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#define STMPE811_FIFO_STA_REG 0x4BU
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#define STMPE811_FIFO_SIZE_REG 0x4CU
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#define STMPE811_TSC_FRACT_XYZ_REG 0x56U
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#define STMPE811_TSC_I_DRIVE_REG 0x58U
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#define STMPE811_TSC_CTRL_REG 0x40U
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#define STMPE811_INT_STA_REG 0x0BU
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#define STMPE811_TSC_DATA_NON_INC_REG 0xD7U
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#define STMPE811_INT_CTRL_REG 0x09U
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#define STMPE811_INT_EN_REG 0x0AU
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/* Touch detected bit */
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#define STMPE811_TSC_CTRL_BIT_TOUCH_DET BIT(7)
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/* Global interrupt enable bit */
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#define STMPE811_INT_CTRL_BIT_GLOBAL_INT BIT(0)
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/* IO expander functionalities */
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#define STMPE811_SYS_CTRL2_BIT_ADC_FCT BIT(0)
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#define STMPE811_SYS_CTRL2_BIT_TS_FCT BIT(1)
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#define STMPE811_SYS_CTRL2_BIT_IO_FCT BIT(2)
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/* Global Interrupts definitions */
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#define STMPE811_INT_BIT_FIFO_THRESHOLD BIT(1) /* FIFO above threshold interrupt */
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#define STMPE811_INT_BIT_TOUCH BIT(0) /* Touch/release is detected interrupt */
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#define STMPE811_INT_ALL BIT_MASK(8) /* All interrupts */
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/* Reset control */
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#define STMPE811_SYS_CTRL1_RESET_ON 0
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#define STMPE811_SYS_CTRL1_RESET_SOFT BIT(1) /* Soft reset */
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/* Delays to ensure registers erasing */
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#define STMPE811_RESET_DELAY_MS 10
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#define STMPE811_WAIT_DELAY_MS 2
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/* Configuration */
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#define STMPE811_FIFO_TH_SINGLE_POINT 1
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#define STMPE811_FIFO_STA_CLEAR 1
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#define STMPE811_FIFO_STA_OPERATIONAL 0
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#define STMPE811_TSC_I_DRIVE_LIMIT 1
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/**
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* Touch Screen Control
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*
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* - bits [1-3] X, Y only acquisition mode
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*/
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#define STMPE811_TSC_CTRL_CONF 3U
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/**
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* Analog-to-digital Converter
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*
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* - bit [3] selects 12 bit ADC
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* - bits [4-6] select ADC conversion time = 80
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*/
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#define STMPE811_ADC_CTRL1_CONF 0x48U
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/**
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* ADC clock speed: 3.25 MHz
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*
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* - 00 : 1.625 MHz
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* - 01 : 3.25 MHz
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* - 10 : 6.5 MHz
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* - 11 : 6.5 MHz
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*/
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#define STMPE811_ADC_CLOCK_SPEED 1
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/**
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* Range and accuracy of the pressure measurement (Z)
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*
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* - Fractional part : 7
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* - Whole part : 1
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*/
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#define STMPE811_TSC_FRACT_XYZ_CONF 1
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struct stmpe811_config {
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struct input_touchscreen_common_config common;
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struct i2c_dt_spec bus;
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struct gpio_dt_spec int_gpio;
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uint8_t panel_driver_settling_time_us;
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uint8_t touch_detect_delay_us;
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uint8_t touch_average_control;
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uint8_t tracking_index;
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int raw_x_min;
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int raw_y_min;
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uint16_t raw_x_max;
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uint16_t raw_y_max;
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};
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struct stmpe811_data {
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const struct device *dev;
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struct k_work processing_work;
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struct gpio_callback int_gpio_cb;
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uint32_t touch_x;
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uint32_t touch_y;
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};
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INPUT_TOUCH_STRUCT_CHECK(struct stmpe811_config);
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static int stmpe811_reset(const struct device *dev)
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{
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const struct stmpe811_config *config = dev->config;
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/* Power down the stmpe811 */
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int ret = i2c_reg_write_byte_dt(&config->bus, STMPE811_SYS_CTRL1_REG,
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STMPE811_SYS_CTRL1_RESET_SOFT);
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if (ret < 0) {
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return ret;
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}
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k_msleep(STMPE811_RESET_DELAY_MS);
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/* Power on the stmpe811 after the power off => all registers are reinitialized */
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ret = i2c_reg_write_byte_dt(&config->bus, STMPE811_SYS_CTRL1_REG,
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STMPE811_SYS_CTRL1_RESET_ON);
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if (ret < 0) {
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return ret;
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}
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k_msleep(STMPE811_WAIT_DELAY_MS);
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return 0;
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}
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static int stmpe811_io_enable_af(const struct device *dev, uint32_t io_pin)
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{
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const struct stmpe811_config *config = dev->config;
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/* Apply ~io_pin as a mask to the current register value */
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return i2c_reg_update_byte_dt(&config->bus, STMPE811_IO_AF_REG, io_pin, 0);
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}
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static uint8_t stmpe811_tsc_config_bits(const struct device *dev)
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{
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const struct stmpe811_config *config = dev->config;
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/**
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* Configuration:
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* - bits [0-2] : panel driver settling time
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* - bits [3-5] : touch detect delay
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* - bits [6-7] : touch average control
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*/
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return config->panel_driver_settling_time_us | config->touch_detect_delay_us << 3 |
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config->touch_average_control << 6;
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}
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static uint8_t stmpe811_tsc_control_bits(const struct device *dev)
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{
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const struct stmpe811_config *config = dev->config;
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/**
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* Touch Screen Control
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*
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* - bit [0] enables TSC
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* - bits [1-3] X, Y only acquisition mode
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* - bits [4-6] window tracking index (set from config)
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* - bit [7] TSC status (writing has no effect)
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*/
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return STMPE811_TSC_CTRL_CONF | config->tracking_index << 4;
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}
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static int stmpe811_ts_init(const struct device *dev)
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{
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const struct stmpe811_config *config = dev->config;
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int err;
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err = stmpe811_reset(dev);
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if (err < 0) {
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return err;
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}
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/* Select TSC pins in TSC alternate mode */
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err = stmpe811_io_enable_af(dev, STMPE811_TOUCH_IO_ALL);
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if (err < 0) {
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return err;
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}
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/**
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* Set the functionalities to be enabled
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* Bits [0-3] disable functionalities if set to 1 (reset value: 0x0f)
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*
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* Apply inverted sum of chosen FCT bits as a mask to the currect register value
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*/
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err = i2c_reg_update_byte_dt(&config->bus, STMPE811_SYS_CTRL2_REG,
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STMPE811_SYS_CTRL2_BIT_IO_FCT | STMPE811_SYS_CTRL2_BIT_TS_FCT |
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STMPE811_SYS_CTRL2_BIT_ADC_FCT, 0);
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if (err < 0) {
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return err;
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}
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/* Select sample time, bit number and ADC reference */
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err = i2c_reg_write_byte_dt(&config->bus, STMPE811_ADC_CTRL1_REG, STMPE811_ADC_CTRL1_CONF);
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if (err < 0) {
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return err;
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}
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/* Select the ADC clock speed */
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err = i2c_reg_write_byte_dt(&config->bus, STMPE811_ADC_CTRL2_REG, STMPE811_ADC_CLOCK_SPEED);
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if (err < 0) {
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return err;
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}
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/* Touch screen configuration */
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err = i2c_reg_write_byte_dt(&config->bus, STMPE811_TSC_CFG_REG,
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stmpe811_tsc_config_bits(dev));
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if (err < 0) {
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return err;
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}
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/* Configure the touch FIFO threshold */
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err = i2c_reg_write_byte_dt(&config->bus, STMPE811_FIFO_TH_REG,
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STMPE811_FIFO_TH_SINGLE_POINT);
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if (err < 0) {
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return err;
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}
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/* Clear the FIFO memory content */
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err = i2c_reg_write_byte_dt(&config->bus, STMPE811_FIFO_STA_REG, STMPE811_FIFO_STA_CLEAR);
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if (err < 0) {
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return err;
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}
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/* Set the range and accuracy of the pressure measurement (Z) */
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err = i2c_reg_write_byte_dt(&config->bus, STMPE811_TSC_FRACT_XYZ_REG,
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STMPE811_TSC_FRACT_XYZ_CONF);
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if (err < 0) {
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return err;
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}
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/* Set the driving capability (limit) of the device for TSC pins */
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err = i2c_reg_write_byte_dt(&config->bus, STMPE811_TSC_I_DRIVE_REG,
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STMPE811_TSC_I_DRIVE_LIMIT);
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if (err < 0) {
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return err;
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}
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/* Touch screen control configuration */
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err = i2c_reg_write_byte_dt(&config->bus, STMPE811_TSC_CTRL_REG,
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stmpe811_tsc_control_bits(dev));
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if (err < 0) {
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return err;
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}
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/**
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* Clear all the status pending bits if any.
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* Writing '1' to this register clears the corresponding bits.
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* This is an 8-bit register, so writing 0xFF clears all.
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*/
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err = i2c_reg_write_byte_dt(&config->bus, STMPE811_INT_STA_REG, STMPE811_INT_ALL);
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if (err < 0) {
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return err;
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}
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/* Put the FIFO back into operation mode */
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err = i2c_reg_write_byte_dt(&config->bus, STMPE811_FIFO_STA_REG,
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STMPE811_FIFO_STA_OPERATIONAL);
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if (err < 0) {
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return err;
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}
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/* Enable FIFO and touch interrupts */
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err = i2c_reg_write_byte_dt(&config->bus, STMPE811_INT_EN_REG,
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STMPE811_INT_BIT_TOUCH | STMPE811_INT_BIT_FIFO_THRESHOLD);
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if (err < 0) {
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LOG_ERR("Could not enable interrupt types (%d)", err);
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return err;
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}
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return 0;
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}
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static int stmpe811_ts_get_data(const struct device *dev)
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{
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const struct stmpe811_config *config = dev->config;
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struct stmpe811_data *data = dev->data;
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uint8_t data_xy[3];
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uint32_t uldata_xy;
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int ret = i2c_burst_read_dt(&config->bus, STMPE811_TSC_DATA_NON_INC_REG, data_xy,
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sizeof(data_xy));
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if (ret < 0) {
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return ret;
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}
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/* Calculate positions values */
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uldata_xy = (data_xy[0] << 16) | (data_xy[1] << 8) | data_xy[2];
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data->touch_x = (uldata_xy >> 12U) & BIT_MASK(12);
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data->touch_y = uldata_xy & BIT_MASK(12);
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return 0;
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}
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static void stmpe811_report_touch(const struct device *dev)
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{
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const struct stmpe811_config *config = dev->config;
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const struct input_touchscreen_common_config *common = &config->common;
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struct stmpe811_data *data = dev->data;
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int x = data->touch_x;
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int y = data->touch_y;
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if (common->screen_width > 0 && common->screen_height > 0) {
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x = (((int)data->touch_x - config->raw_x_min) * common->screen_width) /
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(config->raw_x_max - config->raw_x_min);
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y = (((int)data->touch_y - config->raw_y_min) * common->screen_height) /
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(config->raw_y_max - config->raw_y_min);
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x = CLAMP(x, 0, common->screen_width);
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y = CLAMP(y, 0, common->screen_height);
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}
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input_touchscreen_report_pos(dev, x, y, K_FOREVER);
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input_report_key(dev, INPUT_BTN_TOUCH, 1, true, K_FOREVER);
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}
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static int stmpe811_process(const struct device *dev)
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{
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const struct stmpe811_config *config = dev->config;
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int err;
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uint8_t int_sta, fifo_size, tsc_ctrl;
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err = i2c_reg_read_byte_dt(&config->bus, STMPE811_INT_STA_REG, &int_sta);
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if (err < 0) {
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return err;
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}
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/* Clear processed interrupts */
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err = i2c_reg_write_byte_dt(&config->bus, STMPE811_INT_STA_REG, int_sta);
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if (err < 0) {
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return err;
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}
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if (int_sta & STMPE811_INT_BIT_FIFO_THRESHOLD) {
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/**
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* Report every element in FIFO
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*
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* This requires a while loop to avoid a race condition
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* in which an element is added after reading FIFO_SIZE.
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*
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* Exiting ISR without handling every element in FIFO
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* would prevent FIFO_THRESHOLD interrupt from being triggered again.
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*/
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while (true) {
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err = i2c_reg_read_byte_dt(&config->bus, STMPE811_FIFO_SIZE_REG,
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&fifo_size);
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if (err < 0) {
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return err;
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}
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if (fifo_size == 0) {
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break;
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}
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for (int i = 0; i < fifo_size; i++) {
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err = stmpe811_ts_get_data(dev);
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if (err < 0) {
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return err;
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}
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stmpe811_report_touch(dev);
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}
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}
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}
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/* TOUCH interrupt also gets triggered at release */
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if (int_sta & STMPE811_INT_BIT_TOUCH) {
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err = i2c_reg_read_byte_dt(&config->bus, STMPE811_TSC_CTRL_REG, &tsc_ctrl);
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if (err < 0) {
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return err;
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}
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/* TOUCH interrupt + no touch detected in TSC_CTRL reg <=> release */
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if (!(tsc_ctrl & STMPE811_TSC_CTRL_BIT_TOUCH_DET)) {
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input_report_key(dev, INPUT_BTN_TOUCH, 0, true, K_FOREVER);
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}
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}
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return 0;
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}
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static void stmpe811_work_handler(struct k_work *work)
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{
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struct stmpe811_data *data = CONTAINER_OF(work, struct stmpe811_data, processing_work);
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const struct stmpe811_config *config = data->dev->config;
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stmpe811_process(data->dev);
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/**
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* Reschedule ISR if there was an interrupt triggered during handling (race condition).
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* IRQ is edge-triggered, so otherwise it would never be triggered again.
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*/
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if (gpio_pin_get_dt(&config->int_gpio)) {
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k_work_submit(&data->processing_work);
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}
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}
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static void stmpe811_interrupt_handler(const struct device *dev, struct gpio_callback *cb,
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uint32_t pins)
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{
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struct stmpe811_data *data = CONTAINER_OF(cb, struct stmpe811_data, int_gpio_cb);
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k_work_submit(&data->processing_work);
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}
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static int stmpe811_verify_chip_id(const struct device *dev)
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{
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const struct stmpe811_config *config = dev->config;
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uint8_t buf[2];
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i2c_burst_read_dt(&config->bus, STMPE811_CHP_ID_LSB_REG, buf, 2);
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if (sys_get_be16(buf) != CHIP_ID) {
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return -EINVAL;
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}
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return 0;
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}
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static int stmpe811_init(const struct device *dev)
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{
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const struct stmpe811_config *config = dev->config;
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struct stmpe811_data *data = dev->data;
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int err;
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if (!i2c_is_ready_dt(&config->bus)) {
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LOG_ERR("I2C controller device not ready");
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return -ENODEV;
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}
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data->dev = dev;
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k_work_init(&data->processing_work, stmpe811_work_handler);
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/* Verify CHIP_ID */
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err = stmpe811_verify_chip_id(dev);
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if (err) {
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LOG_ERR("CHIP ID verification failed (%d)", err);
|
|
return err;
|
|
}
|
|
|
|
/* Initialize */
|
|
err = stmpe811_ts_init(dev);
|
|
if (err) {
|
|
LOG_ERR("Touch screen controller initialization failed (%d)", err);
|
|
return err;
|
|
}
|
|
|
|
/* Initialize GPIO interrupt */
|
|
if (!gpio_is_ready_dt(&config->int_gpio)) {
|
|
LOG_ERR("Interrupt GPIO controller device not ready");
|
|
return -ENODEV;
|
|
}
|
|
|
|
err = gpio_pin_configure_dt(&config->int_gpio, GPIO_INPUT);
|
|
if (err < 0) {
|
|
LOG_ERR("Could not configure interrupt GPIO pin (%d)", err);
|
|
return err;
|
|
}
|
|
|
|
err = gpio_pin_interrupt_configure_dt(&config->int_gpio, GPIO_INT_EDGE_TO_ACTIVE);
|
|
if (err < 0) {
|
|
LOG_ERR("Could not configure GPIO interrupt (%d)", err);
|
|
return err;
|
|
}
|
|
|
|
gpio_init_callback(&data->int_gpio_cb, stmpe811_interrupt_handler,
|
|
BIT(config->int_gpio.pin));
|
|
err = gpio_add_callback_dt(&config->int_gpio, &data->int_gpio_cb);
|
|
if (err < 0) {
|
|
LOG_ERR("Could not set GPIO callback (%d)", err);
|
|
return err;
|
|
}
|
|
|
|
/* Enable global interrupts */
|
|
err = i2c_reg_write_byte_dt(&config->bus, STMPE811_INT_CTRL_REG,
|
|
STMPE811_INT_CTRL_BIT_GLOBAL_INT);
|
|
if (err < 0) {
|
|
LOG_ERR("Could not enable global interrupts (%d)", err);
|
|
return err;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
#define STMPE811_DEFINE(index) \
|
|
BUILD_ASSERT(DT_INST_PROP_OR(index, raw_x_max, 4096) > \
|
|
DT_INST_PROP_OR(index, raw_x_min, 0), \
|
|
"raw-x-max should be larger than raw-x-min"); \
|
|
BUILD_ASSERT(DT_INST_PROP_OR(index, raw_y_max, 4096) > \
|
|
DT_INST_PROP_OR(index, raw_y_min, 0), \
|
|
"raw-y-max should be larger than raw-y-min"); \
|
|
static const struct stmpe811_config stmpe811_config_##index = { \
|
|
.common = INPUT_TOUCH_DT_INST_COMMON_CONFIG_INIT(index), \
|
|
.bus = I2C_DT_SPEC_INST_GET(index), \
|
|
.int_gpio = GPIO_DT_SPEC_INST_GET(index, int_gpios), \
|
|
.panel_driver_settling_time_us = \
|
|
DT_INST_ENUM_IDX(index, panel_driver_settling_time_us), \
|
|
.raw_x_min = DT_INST_PROP_OR(index, raw_x_min, 0), \
|
|
.raw_y_min = DT_INST_PROP_OR(index, raw_y_min, 0), \
|
|
.raw_x_max = DT_INST_PROP_OR(index, raw_x_max, 4096), \
|
|
.raw_y_max = DT_INST_PROP_OR(index, raw_y_max, 4096), \
|
|
.touch_detect_delay_us = DT_INST_ENUM_IDX(index, touch_detect_delay_us), \
|
|
.touch_average_control = DT_INST_ENUM_IDX(index, touch_average_control), \
|
|
.tracking_index = DT_INST_ENUM_IDX(index, tracking_index)}; \
|
|
static struct stmpe811_data stmpe811_data_##index; \
|
|
DEVICE_DT_INST_DEFINE(index, stmpe811_init, NULL, &stmpe811_data_##index, \
|
|
&stmpe811_config_##index, POST_KERNEL, CONFIG_INPUT_INIT_PRIORITY, \
|
|
NULL);
|
|
|
|
DT_INST_FOREACH_STATUS_OKAY(STMPE811_DEFINE)
|