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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 | /* * Copyright (c) 2016 Intel Corporation * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #include <device.h> #include <i2c.h> #include <sensor.h> #include <misc/__assert.h> #include "max44009.h" static int max44009_reg_read(struct max44009_data *drv_data, uint8_t reg, uint8_t *val, bool send_stop) { struct i2c_msg msgs[2] = { { .buf = ®, .len = 1, .flags = I2C_MSG_WRITE, }, { .buf = val, .len = 1, .flags = I2C_MSG_READ, }, }; if (send_stop) { msgs[1].flags |= I2C_MSG_STOP; } if (i2c_transfer(drv_data->i2c, msgs, 2, MAX44009_I2C_ADDRESS) != 0) { return -EIO; } return 0; } static int max44009_reg_write(struct max44009_data *drv_data, uint8_t reg, uint8_t val) { uint8_t tx_buf[2] = {reg, val}; return i2c_write(drv_data->i2c, tx_buf, sizeof(tx_buf), MAX44009_I2C_ADDRESS); } static int max44009_reg_update(struct max44009_data *drv_data, uint8_t reg, uint8_t mask, uint8_t val) { uint8_t old_val = 0; uint8_t new_val = 0; if (max44009_reg_read(drv_data, reg, &old_val, true) != 0) { return -EIO; } new_val = old_val & ~mask; new_val |= val & mask; return max44009_reg_write(drv_data, reg, new_val); } static int max44009_attr_set(struct device *dev, enum sensor_channel chan, enum sensor_attribute attr, const struct sensor_value *val) { struct max44009_data *drv_data = dev->driver_data; uint8_t value; uint32_t cr; if (chan != SENSOR_CHAN_LIGHT) { return -ENOTSUP; } switch (attr) { case SENSOR_ATTR_SAMPLING_FREQUENCY: if (val->type != SENSOR_VALUE_TYPE_INT_PLUS_MICRO) { return -ENOTSUP; } /* convert rate to mHz */ cr = val->val1 * 1000 + val->val2 / 1000; /* the sensor supports 1.25Hz or continuous conversion */ switch (cr) { case 1250: value = 0; break; default: value = MAX44009_CONTINUOUS_SAMPLING; } if (max44009_reg_update(drv_data, MAX44009_REG_CONFIG, MAX44009_SAMPLING_CONTROL_BIT, value) != 0) { SYS_LOG_DBG("Failed to set attribute!"); return -EIO; } return 0; default: return -ENOTSUP; } return 0; } static int max44009_sample_fetch(struct device *dev, enum sensor_channel chan) { struct max44009_data *drv_data = dev->driver_data; uint8_t val_h, val_l; __ASSERT_NO_MSG(chan == SENSOR_CHAN_ALL || chan == SENSOR_CHAN_LIGHT); drv_data->sample = 0; if (max44009_reg_read(drv_data, MAX44009_REG_LUX_HIGH_BYTE, &val_h, false) != 0) { return -EIO; } if (max44009_reg_read(drv_data, MAX44009_REG_LUX_LOW_BYTE, &val_l, true) != 0) { return -EIO; } drv_data->sample = ((uint16_t)val_h) << 8; drv_data->sample += val_l; return 0; } static int max44009_channel_get(struct device *dev, enum sensor_channel chan, struct sensor_value *val) { struct max44009_data *drv_data = dev->driver_data; uint32_t uval; if (chan != SENSOR_CHAN_LIGHT) { return -ENOTSUP; } /** * sample consists of 4 bits of exponent and 8 bits of mantissa * bits 15 to 12 are exponent bits * bits 11 to 8 and 3 to 0 are the mantissa bits */ uval = drv_data->sample; uval = (uval & MAX44009_MANTISSA_LOW_NIBBLE_MASK) + ((uval & MAX44009_MANTISSA_HIGH_NIBBLE_MASK) >> 4); uval = uval << (drv_data->sample >> MAX44009_SAMPLE_EXPONENT_SHIFT); val->type = SENSOR_VALUE_TYPE_DOUBLE; /* lux is the integer of sample output multiplied by 0.045. */ val->dval = ((double)uval) * 0.045; return 0; } static const struct sensor_driver_api max44009_driver_api = { .attr_set = max44009_attr_set, .sample_fetch = max44009_sample_fetch, .channel_get = max44009_channel_get, }; int max44009_init(struct device *dev) { struct max44009_data *drv_data = dev->driver_data; drv_data->i2c = device_get_binding(CONFIG_MAX44009_I2C_DEV_NAME); if (drv_data->i2c == NULL) { SYS_LOG_DBG("Failed to get pointer to %s device!", CONFIG_MAX44009_I2C_DEV_NAME); return -EINVAL; } dev->driver_api = &max44009_driver_api; return 0; } static struct max44009_data max44009_drv_data; DEVICE_INIT(max44009, CONFIG_MAX44009_DRV_NAME, max44009_init, &max44009_drv_data, NULL, POST_KERNEL, CONFIG_SENSOR_INIT_PRIORITY); |