mirror of
https://github.com/RIOT-OS/RIOT.git
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286 lines
8.6 KiB
C
286 lines
8.6 KiB
C
/*
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* Copyright (C) 2019 Inria
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*
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* This file is subject to the terms and conditions of the GNU Lesser
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* General Public License v2.1. See the file LICENSE in the top level
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* directory for more details.
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*/
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/**
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* @ingroup drivers_stmpe811
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* @{
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*
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* @file
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* @brief Device driver implementation for the STMPE811 touchscreen controller.
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*
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* @author Alexandre Abadie <alexandre.abadie@inria.fr>
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*
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* @}
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*/
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#include <inttypes.h>
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#include "xtimer.h"
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#include "periph/i2c.h"
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#include "periph/gpio.h"
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#include "stmpe811.h"
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#include "stmpe811_constants.h"
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#include "stmpe811_params.h"
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#define ENABLE_DEBUG 0
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#include "debug.h"
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#define STMPE811_DEV_I2C (dev->params.i2c)
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#define STMPE811_DEV_ADDR (dev->params.addr)
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static int _soft_reset(const stmpe811_t *dev)
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{
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if (i2c_write_reg(STMPE811_DEV_I2C, STMPE811_DEV_ADDR,
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STMPE811_SYS_CTRL1, STMPE811_SYS_CTRL1_SOFT_RESET, 0) < 0) {
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DEBUG("[stmpe811] soft reset: cannot write soft reset bit to SYS_CTRL1 register\n");
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return -STMPE811_ERR_I2C;
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}
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xtimer_msleep(10);
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if (i2c_write_reg(STMPE811_DEV_I2C, STMPE811_DEV_ADDR,
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STMPE811_SYS_CTRL1, 0, 0) < 0) {
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DEBUG("[stmpe811] soft reset: cannot clear SYS_CTRL1 register\n");
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return -STMPE811_ERR_I2C;
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}
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xtimer_msleep(2);
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return STMPE811_OK;
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}
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static void _reset_fifo(const stmpe811_t *dev)
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{
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i2c_write_reg(STMPE811_DEV_I2C, STMPE811_DEV_ADDR,
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STMPE811_FIFO_CTRL_STA, STMPE811_FIFO_CTRL_STA_RESET, 0);
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i2c_write_reg(STMPE811_DEV_I2C, STMPE811_DEV_ADDR,
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STMPE811_FIFO_CTRL_STA, 0, 0);
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}
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static void _clear_interrupt_status(const stmpe811_t *dev)
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{
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i2c_write_reg(STMPE811_DEV_I2C, STMPE811_DEV_ADDR, STMPE811_INT_STA, 0xff, 0);
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}
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int stmpe811_init(stmpe811_t *dev, const stmpe811_params_t * params, touch_event_cb_t cb, void *arg)
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{
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dev->params = *params;
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int ret = STMPE811_OK;
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/* Acquire I2C device */
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i2c_acquire(STMPE811_DEV_I2C);
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uint16_t device_id;
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if (i2c_read_regs(STMPE811_DEV_I2C, STMPE811_DEV_ADDR,
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STMPE811_CHIP_ID, &device_id, 2, 0) < 0) {
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DEBUG("[stmpe811] init: cannot read CHIP_ID register\n");
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i2c_release(STMPE811_DEV_I2C);
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return -STMPE811_ERR_I2C;
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}
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device_id = (device_id << 8) | (device_id >> 8);
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if (device_id != STMPE811_CHIP_ID_VALUE) {
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DEBUG("[stmpe811] init: invalid device id (actual: 0x%04X, expected: 0x%04X)\n",
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device_id, STMPE811_CHIP_ID_VALUE);
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i2c_release(STMPE811_DEV_I2C);
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return -STMPE811_ERR_NODEV;
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}
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DEBUG("[stmpe811] init: valid device\n");
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ret = _soft_reset(dev);
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if (ret != STMPE811_OK) {
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DEBUG("[stmpe811] init: reset failed\n");
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i2c_release(STMPE811_DEV_I2C);
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return -STMPE811_ERR_RESET;
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}
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DEBUG("[stmpe811] init: soft reset done\n");
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/* Initialization sequence */
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/* disable temperature sensor and GPIO */
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ret = i2c_write_reg(STMPE811_DEV_I2C, STMPE811_DEV_ADDR,
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STMPE811_SYS_CTRL2,
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(STMPE811_SYS_CTRL2_TS_OFF | STMPE811_SYS_CTRL2_GPIO_OFF), 0);
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/* set to 80 cycles and adc resolution to 12 bit*/
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uint8_t reg = ((uint8_t)(STMPE811_ADC_CTRL1_SAMPLE_TIME_80 << STMPE811_ADC_CTRL1_SAMPLE_TIME_POS) |
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STMPE811_ADC_CTRL1_MOD_12B);
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ret += i2c_write_reg(STMPE811_DEV_I2C, STMPE811_DEV_ADDR,
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STMPE811_ADC_CTRL1, reg, 0);
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/* set adc clock speed to 3.25 MHz */
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ret += i2c_write_reg(STMPE811_DEV_I2C, STMPE811_DEV_ADDR,
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STMPE811_ADC_CTRL2, STMPE811_ADC_CTRL2_FREQ_3_25MHZ, 0);
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/* set GPIO AF to function as ts/adc */
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ret += i2c_write_reg(STMPE811_DEV_I2C, STMPE811_DEV_ADDR,
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STMPE811_GPIO_ALT_FUNCTION, 0x00, 0);
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/* set touchscreen configuration */
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reg = ((uint8_t)(STMPE811_TSC_CFG_AVE_CTRL_4 << STMPE811_TSC_CFG_AVE_CTRL_POS) |
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(uint8_t)(STMPE811_TSC_CFG_TOUCH_DET_DELAY_500US << STMPE811_TSC_CFG_TOUCH_DET_DELAY_POS) |
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(STMPE811_TSC_CFG_SETTLING_500US));
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ret += i2c_write_reg(STMPE811_DEV_I2C, STMPE811_DEV_ADDR,
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STMPE811_TSC_CFG, reg, 0);
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/* set fifo threshold */
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ret += i2c_write_reg(STMPE811_DEV_I2C, STMPE811_DEV_ADDR,
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STMPE811_FIFO_TH, 0x01, 0);
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/* reset fifo */
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_reset_fifo(dev);
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/* set fractional part to 7, whole part to 1 */
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ret += i2c_write_reg(STMPE811_DEV_I2C, STMPE811_DEV_ADDR,
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STMPE811_TSC_FRACTION_Z, STMPE811_TSC_FRACTION_Z_7_1, 0);
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/* set current limit value to 50 mA */
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ret += i2c_write_reg(STMPE811_DEV_I2C, STMPE811_DEV_ADDR,
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STMPE811_TSC_I_DRIVE, STMPE811_TSC_I_DRIVE_50MA, 0);
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/* enable touchscreen clock */
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ret += i2c_read_reg(STMPE811_DEV_I2C, STMPE811_DEV_ADDR,
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STMPE811_SYS_CTRL2, ®, 0);
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reg &= ~STMPE811_SYS_CTRL2_TSC_OFF;
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ret += i2c_write_reg(STMPE811_DEV_I2C, STMPE811_DEV_ADDR,
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STMPE811_SYS_CTRL2, reg, 0);
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ret += i2c_read_reg(STMPE811_DEV_I2C, STMPE811_DEV_ADDR,
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STMPE811_TSC_CTRL, ®, 0);
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reg |= STMPE811_TSC_CTRL_EN;
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ret += i2c_write_reg(STMPE811_DEV_I2C, STMPE811_DEV_ADDR,
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STMPE811_TSC_CTRL, reg, 0);
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/* clear interrupt status */
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_clear_interrupt_status(dev);
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if (gpio_is_valid(dev->params.int_pin) && cb) {
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DEBUG("[stmpe811] init: configuring touchscreen interrupt\n");
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gpio_init_int(dev->params.int_pin, GPIO_IN, GPIO_FALLING, cb, arg);
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/* Enable touchscreen interrupt */
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ret += i2c_write_reg(STMPE811_DEV_I2C, STMPE811_DEV_ADDR,
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STMPE811_INT_EN, STMPE811_INT_EN_TOUCH_DET, 0);
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/* Enable global interrupt */
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ret += i2c_write_reg(STMPE811_DEV_I2C, STMPE811_DEV_ADDR,
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STMPE811_INT_CTRL, STMPE811_INT_CTRL_GLOBAL_INT | STMPE811_INT_CTRL_INT_TYPE, 0);
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}
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if (ret < 0) {
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i2c_release(STMPE811_DEV_I2C);
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DEBUG("[stmpe811] init: initialization sequence failed\n");
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return -STMPE811_ERR_I2C;
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}
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/* Release I2C device */
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i2c_release(STMPE811_DEV_I2C);
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DEBUG("[stmpe811] initialization successful\n");
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return ret;
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}
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int stmpe811_read_touch_position(stmpe811_t *dev, stmpe811_touch_position_t *position)
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{
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uint16_t tmp_x, tmp_y;
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/* Acquire I2C device */
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i2c_acquire(STMPE811_DEV_I2C);
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/* Ensure there's a least one position measured in the FIFO */
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uint8_t fifo_size = 0;
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do {
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i2c_read_reg(STMPE811_DEV_I2C, STMPE811_DEV_ADDR,
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STMPE811_FIFO_SIZE, &fifo_size, 0);
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} while (!fifo_size);
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uint8_t xyz[4];
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uint32_t xyz_ul;
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if (i2c_read_regs(STMPE811_DEV_I2C, STMPE811_DEV_ADDR,
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STMPE811_TSC_DATA_NON_INC, &xyz, sizeof(xyz), 0) < 0) {
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DEBUG("[stmpe811] position: cannot read position\n");
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i2c_release(STMPE811_DEV_I2C);
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return -STMPE811_ERR_I2C;
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}
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/* Release I2C device */
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i2c_release(STMPE811_DEV_I2C);
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xyz_ul = ((uint32_t)xyz[0] << 24) | ((uint32_t)xyz[1] << 16) | \
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((uint32_t)xyz[2] << 8) | (xyz[3] << 0);
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tmp_x = (xyz_ul >> 20) & 0xfff;
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tmp_y = (xyz_ul >> 8) & 0xfff;
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/* Y value first correction */
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tmp_y -= 360;
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/* Y value second correction */
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tmp_y /= 11;
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/* clamp y position */
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if (tmp_y > dev->params.ymax) {
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tmp_y = dev->prev_y;
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}
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/* X value first correction */
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if (tmp_x <= 3000) {
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tmp_x = 3870 - tmp_x;
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}
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else {
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tmp_x = 3800 - tmp_x;
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}
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/* X value second correction */
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tmp_x /= 15;
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/* clamp x position */
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if (tmp_x > dev->params.xmax) {
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tmp_x = dev->prev_x;
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}
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dev->prev_x = tmp_x;
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dev->prev_y = tmp_y;
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position->x = tmp_x;
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position->y = tmp_y;
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return STMPE811_OK;
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}
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int stmpe811_read_touch_state(const stmpe811_t *dev, stmpe811_touch_state_t *state)
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{
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uint8_t val;
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/* Acquire I2C device */
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i2c_acquire(STMPE811_DEV_I2C);
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if (i2c_read_reg(STMPE811_DEV_I2C, STMPE811_DEV_ADDR, STMPE811_TSC_CTRL, &val, 0) < 0) {
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DEBUG("[stmpe811] position: cannot read touch state\n");
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i2c_release(STMPE811_DEV_I2C);
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return -STMPE811_ERR_I2C;
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}
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_clear_interrupt_status(dev);
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if ((val & STMPE811_TSC_CTRL_STA)) {
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*state = STMPE811_TOUCH_STATE_PRESSED;
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}
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else {
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_reset_fifo(dev);
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*state = STMPE811_TOUCH_STATE_RELEASED;
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}
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/* Release I2C device */
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i2c_release(STMPE811_DEV_I2C);
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return STMPE811_OK;
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}
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