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