/**************************************************************************** * drivers/sensors/as726x.c * Character driver for the AS7263 6-Ch NIR Spectral Sensing Engine * and AS7262 Consumer Grade Smart 6-Channel VIS Sensor * * Copyright (C) 2019 Fabian Justi. All rights reserved. * Author: Fabian Justi and * Andreas Kurz * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * 3. Neither the name NuttX nor the names of its contributors may be * used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include #include #include #include #include #include #include #include #include #include #if defined(CONFIG_I2C) && defined(CONFIG_SENSORS_AS726X) /**************************************************************************** * Pre-process Definitions ****************************************************************************/ #ifndef CONFIG_AS726X_I2C_FREQUENCY # define CONFIG_AS726X_I2C_FREQUENCY 100000 #endif #define AS726X_INTEGRATION_TIME 50 #define AS726X_GAIN 0b01 /* Set gain to 64x */ #define AS726X_MEASURMENT_MODE 0b10 /* One-shot reading of VBGYOR or RSTUVW */ /**************************************************************************** * Private Types ****************************************************************************/ struct as726x_dev_s { FAR struct i2c_master_s *i2c; /* I2C interface */ uint8_t addr; /* I2C address */ }; /**************************************************************************** * Private Function Prototypes ****************************************************************************/ static float as726x_getcalibrated(FAR struct as726x_dev_s *priv, uint8_t regaddr); static int16_t as726x_getchannel(FAR struct as726x_dev_s *priv, uint8_t regaddr); /* I2C Helpers */ static uint8_t read_register(FAR struct as726x_dev_s *priv, uint8_t addr); static uint8_t as726x_read8(FAR struct as726x_dev_s *priv, uint8_t regval); static void write_register(FAR struct as726x_dev_s *priv, uint8_t addr, uint8_t val); static void as726x_write8(FAR struct as726x_dev_s *priv, uint8_t regaddr, uint8_t regval); /* Character driver methods */ static ssize_t as726x_read(FAR struct file *filep, FAR char *buffer, size_t buflen); static ssize_t as726x_write(FAR struct file *filep, FAR const char *buffer, size_t buflen); /**************************************************************************** * Private Data ****************************************************************************/ static const struct file_operations g_as726x_fops = { NULL, /* open */ NULL, /* close */ as726x_read, /* read */ as726x_write, /* write */ }; /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Name: as726x_getcalibrated * * Description: * Read calibrated value * ****************************************************************************/ static float as726x_getcalibrated(FAR struct as726x_dev_s *priv, uint8_t regaddr) { uint8_t byte0 = as726x_read8(priv, regaddr + 0); uint8_t byte1 = as726x_read8(priv, regaddr + 1); uint8_t byte2 = as726x_read8(priv, regaddr + 2); uint8_t byte3 = as726x_read8(priv, regaddr + 3); uint32_t colourdata = ((uint32_t) byte0 << (8 * 3)); colourdata |= ((uint32_t) byte1 << (8 * 2)); colourdata |= ((uint32_t) byte2 << (8 * 1)); colourdata |= ((uint32_t) byte3 << (8 * 0)); return *((FAR float *)(&colourdata)); } /**************************************************************************** * Name: as726x_getchannel * * Description: * Read colour channel * ****************************************************************************/ static int16_t as726x_getchannel(FAR struct as726x_dev_s *priv, uint8_t regaddr) { int16_t colourdata = as726x_read8(priv, regaddr) << 8; colourdata |= as726x_read8(priv, regaddr + 1); return colourdata; } /**************************************************************************** * Name: as726x_read8 * * Description: * Read 8-bit register * ****************************************************************************/ static uint8_t read_register(FAR struct as726x_dev_s *priv, uint8_t addr) { struct i2c_config_s config; uint8_t regval = 0; int ret; config.frequency = CONFIG_AS726X_I2C_FREQUENCY; config.address = AS726X_I2C_ADDR; config.addrlen = 7; ret = i2c_write(priv->i2c, &config, &addr, 1); if (ret < 0) { snerr("ERROR: i2c_write failed: %d\n", ret); return ret; } ret = i2c_read(priv->i2c, &config, ®val, 1); if (ret < 0) { snerr("ERROR: i2c_read failed: %d\n", ret); return ret; } return regval; } static uint8_t as726x_read8(FAR struct as726x_dev_s *priv, uint8_t regaddr) { uint8_t status; status = read_register(priv, AS72XX_SLAVE_STATUS_REG); if ((status & AS72XX_SLAVE_RX_VALID) != 0) { /* There is data to be read. * Read the byte but do nothing with it. */ read_register(priv, AS72XX_SLAVE_READ_REG); } /* Wait for WRITE flag to clear */ while (1) { status = read_register(priv, AS72XX_SLAVE_STATUS_REG); if ((status & AS72XX_SLAVE_TX_VALID) == 0) { break; /* If TX bit is clear, it is ok to write */ } nxsig_usleep(AS726X_POLLING_DELAY); } /* Send the virtual register address (bit 7 should be 0 to indicate we are * reading a register). */ write_register(priv, AS72XX_SLAVE_WRITE_REG, regaddr); /* Wait for READ flag to be set */ while (1) { status = read_register(priv, AS72XX_SLAVE_STATUS_REG); if ((status & AS72XX_SLAVE_RX_VALID) != 0) { break; /* Read data is ready. */ } nxsig_usleep(AS726X_POLLING_DELAY); } uint8_t incoming = read_register(priv, AS72XX_SLAVE_READ_REG); return incoming; } /**************************************************************************** * Name: as726x_write8 * * Description: * Write from an 8-bit register * ****************************************************************************/ static void write_register(FAR struct as726x_dev_s *priv, uint8_t addr, uint8_t val) { struct i2c_config_s config; uint8_t msg[2] = { 0 }; int ret; config.frequency = CONFIG_AS726X_I2C_FREQUENCY; config.address = AS726X_I2C_ADDR; config.addrlen = 7; msg[0] = addr; msg[1] = val; ret = i2c_write(priv->i2c, &config, msg, 2); if (ret < 0) { snerr("ERROR: i2c_write failed: %d\n", ret); return; } } static void as726x_write8(FAR struct as726x_dev_s *priv, uint8_t regaddr, uint8_t regval) { uint8_t status; while (1) { status = read_register(priv, AS72XX_SLAVE_STATUS_REG); if ((status & AS72XX_SLAVE_TX_VALID) == 0) { /* No inbound TX pending at slave. Okay to write now. */ break; } nxsig_usleep(AS726X_POLLING_DELAY); } /* Send the virtual register address (setting bit 7 to indicate we are * writing to a register). */ write_register(priv, AS72XX_SLAVE_WRITE_REG, (regaddr | 0x80)); /* Wait for WRITE register to be empty */ while (1) { status = read_register(priv, AS72XX_SLAVE_STATUS_REG); if ((status & AS72XX_SLAVE_TX_VALID) == 0) { /* No inbound TX pending at slave. Okay to write now. */ break; } nxsig_usleep(AS726X_POLLING_DELAY); } /* Send the data to complete the operation. */ write_register(priv, AS72XX_SLAVE_WRITE_REG, regval); } /**************************************************************************** * Name: as726x_read ****************************************************************************/ static ssize_t as726x_read(FAR struct file *filep, FAR char *buffer, size_t buflen) { FAR struct inode *inode = filep->f_inode; FAR struct as726x_dev_s *priv = inode->i_private; FAR struct as726x_sensor_data_s *data = (FAR struct as726x_sensor_data_s *)buffer; /* Check if the user is reading the right size */ if (buflen < sizeof(FAR struct as726x_sensor_data_s)) { snerr("ERROR: Not enough memory for reading all channels.\n"); return -ENOSYS; } else { data->v_r_value = as726x_getchannel(priv, AS726X_V_R); data->b_s_value = as726x_getchannel(priv, AS726X_B_S); data->g_t_value = as726x_getchannel(priv, AS726X_G_T); data->y_u_value = as726x_getchannel(priv, AS726X_Y_U); data->o_v_value = as726x_getchannel(priv, AS726X_O_V); data->r_w_value = as726x_getchannel(priv, AS726X_R_W); } return buflen; } /**************************************************************************** * Name: as726x_write ****************************************************************************/ static ssize_t as726x_write(FAR struct file *filep, FAR const char *buffer, size_t buflen) { return -ENOSYS; } /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: as726x_register * * Description: * Register the AS726X character device as 'devpath' * * Input Parameters: * devpath - The full path to the driver to register. E.g., "/dev/spectr0" * i2c - An instance of the I2C interface to use to communicate with AS726X * addr - The I2C address of the AS726X. * * Returned Value: * Zero (OK) on success; a negated errno value on failure. * ****************************************************************************/ int as726x_register(FAR const char *devpath, FAR struct i2c_master_s *i2c) { FAR struct as726x_dev_s *priv; uint8_t _sensor_version; uint8_t value; int ret; /* Sanity check */ DEBUGASSERT(i2c != NULL); /* Initialize the AS726X device structure */ priv = kmm_malloc(sizeof(struct as726x_dev_s)); if (priv == NULL) { snerr("ERROR: Failed to allocate instance\n"); return -ENOMEM; } priv->i2c = i2c; priv->addr = AS726X_I2C_ADDR; /* Check HW version for AS7262 and AS7263 */ _sensor_version = as726x_read8(priv, AS726X_HW_VERSION); if (_sensor_version != 0x3e && _sensor_version != 0x3f) { snerr("ID (should be 0x3e or 0x3f): 0x %d\n", ret); } /* Initialize the device * Read the register value toggle and disable led */ ret = as726x_read8(priv, AS726X_LED_CONTROL); if (ret < 0) { snerr("ERROR: Failed to initialize the AS726X!\n"); return ret; } value = ret; value &= ~(1 << 0); /* Clear the bit */ as726x_write8(priv, AS726X_LED_CONTROL, value); /* If you use Mode 2 or 3 (all the colors) then integration time is double. * 140*2 = 280ms between readings. * 50 * 2.8ms = 140ms. 0 to 255 is valid. */ as726x_write8(priv, AS726X_INT_T, AS726X_INTEGRATION_TIME); ret = as726x_read8(priv, AS726X_CONTROL_SETUP); if (ret < 0) { snerr("ERROR: Failed to initialize the AS726X!\n"); return ret; } value = ret; value &= 0b11001111; /* Clear GAIN bits */ value |= (AS726X_GAIN << 4); /* Set GAIN bits with user's choice */ as726x_write8(priv, AS726X_CONTROL_SETUP, value); ret = as726x_read8(priv, AS726X_CONTROL_SETUP); if (ret < 0) { snerr("ERROR: Failed to initialize the AS726X!\n"); return ret; } value = ret; value &= 0b11110011; /* Clear BANK bits */ value |= (AS726X_MEASURMENT_MODE << 2); /* Set BANK bits with user's * choice */ as726x_write8(priv, AS726X_CONTROL_SETUP, value); /* Register the character driver */ ret = register_driver(devpath, &g_as726x_fops, 0666, priv); if (ret < 0) { snerr("ERROR: Failed to register driver: %d\n", ret); kmm_free(priv); } return ret; } #endif /* CONFIG_I2C && CONFIG_SENSORS_AS726X */