1 /*
2 * Copyright (c) 2016 Intel Corporation
3 *
4 * SPDX-License-Identifier: Apache-2.0
5 */
6
7 #define DT_DRV_COMPAT maxim_max44009
8
9 #include <zephyr/device.h>
10 #include <zephyr/drivers/i2c.h>
11 #include <zephyr/drivers/sensor.h>
12 #include <zephyr/sys/__assert.h>
13 #include <zephyr/logging/log.h>
14
15 #include "max44009.h"
16
17 LOG_MODULE_REGISTER(MAX44009, CONFIG_SENSOR_LOG_LEVEL);
18
max44009_reg_read(const struct device * dev,uint8_t reg,uint8_t * val,bool send_stop)19 static int max44009_reg_read(const struct device *dev, uint8_t reg,
20 uint8_t *val, bool send_stop)
21 {
22 const struct max44009_config *config = dev->config;
23 struct i2c_msg msgs[2] = {
24 {
25 .buf = ®,
26 .len = 1,
27 .flags = I2C_MSG_WRITE,
28 },
29 {
30 .buf = val,
31 .len = 1,
32 .flags = I2C_MSG_READ,
33 },
34 };
35
36 if (send_stop) {
37 msgs[1].flags |= I2C_MSG_STOP;
38 }
39
40 if (i2c_transfer_dt(&config->i2c, msgs, 2) != 0) {
41 return -EIO;
42 }
43
44 return 0;
45 }
46
max44009_reg_write(const struct device * dev,uint8_t reg,uint8_t val)47 static int max44009_reg_write(const struct device *dev, uint8_t reg,
48 uint8_t val)
49 {
50 const struct max44009_config *config = dev->config;
51 uint8_t tx_buf[2] = {reg, val};
52
53 return i2c_write_dt(&config->i2c, tx_buf, sizeof(tx_buf));
54 }
55
max44009_reg_update(const struct device * dev,uint8_t reg,uint8_t mask,uint8_t val)56 static int max44009_reg_update(const struct device *dev, uint8_t reg,
57 uint8_t mask, uint8_t val)
58 {
59 uint8_t old_val = 0U;
60 uint8_t new_val = 0U;
61
62 if (max44009_reg_read(dev, reg, &old_val, true) != 0) {
63 return -EIO;
64 }
65
66 new_val = old_val & ~mask;
67 new_val |= val & mask;
68
69 return max44009_reg_write(dev, reg, new_val);
70 }
71
max44009_attr_set(const struct device * dev,enum sensor_channel chan,enum sensor_attribute attr,const struct sensor_value * val)72 static int max44009_attr_set(const struct device *dev,
73 enum sensor_channel chan,
74 enum sensor_attribute attr,
75 const struct sensor_value *val)
76 {
77 uint8_t value;
78 uint32_t cr;
79
80 if (chan != SENSOR_CHAN_LIGHT) {
81 return -ENOTSUP;
82 }
83
84 switch (attr) {
85 case SENSOR_ATTR_SAMPLING_FREQUENCY:
86 /* convert rate to mHz */
87 cr = val->val1 * 1000 + val->val2 / 1000;
88
89 /* the sensor supports 1.25Hz or continuous conversion */
90 switch (cr) {
91 case 1250:
92 value = 0U;
93 break;
94 default:
95 value = MAX44009_CONTINUOUS_SAMPLING;
96 }
97
98 if (max44009_reg_update(dev, MAX44009_REG_CONFIG,
99 MAX44009_SAMPLING_CONTROL_BIT,
100 value) != 0) {
101 LOG_DBG("Failed to set attribute!");
102 return -EIO;
103 }
104
105 return 0;
106
107 default:
108 return -ENOTSUP;
109 }
110
111 return 0;
112 }
113
max44009_sample_fetch(const struct device * dev,enum sensor_channel chan)114 static int max44009_sample_fetch(const struct device *dev,
115 enum sensor_channel chan)
116 {
117 struct max44009_data *drv_data = dev->data;
118 uint8_t val_h, val_l;
119
120 __ASSERT_NO_MSG(chan == SENSOR_CHAN_ALL || chan == SENSOR_CHAN_LIGHT);
121
122 drv_data->sample = 0U;
123
124 if (max44009_reg_read(dev, MAX44009_REG_LUX_HIGH_BYTE, &val_h,
125 false) != 0) {
126 return -EIO;
127 }
128
129 if (max44009_reg_read(dev, MAX44009_REG_LUX_LOW_BYTE, &val_l,
130 true) != 0) {
131 return -EIO;
132 }
133
134 drv_data->sample = ((uint16_t)val_h) << 8;
135 drv_data->sample += val_l;
136
137 return 0;
138 }
139
max44009_channel_get(const struct device * dev,enum sensor_channel chan,struct sensor_value * val)140 static int max44009_channel_get(const struct device *dev,
141 enum sensor_channel chan,
142 struct sensor_value *val)
143 {
144 struct max44009_data *drv_data = dev->data;
145 uint32_t uval;
146
147 if (chan != SENSOR_CHAN_LIGHT) {
148 return -ENOTSUP;
149 }
150
151 /**
152 * sample consists of 4 bits of exponent and 8 bits of mantissa
153 * bits 15 to 12 are exponent bits
154 * bits 11 to 8 and 3 to 0 are the mantissa bits
155 */
156 uval = drv_data->sample;
157 uval = (uval & MAX44009_MANTISSA_LOW_NIBBLE_MASK) +
158 ((uval & MAX44009_MANTISSA_HIGH_NIBBLE_MASK) >> 4);
159 uval = uval << (drv_data->sample >> MAX44009_SAMPLE_EXPONENT_SHIFT);
160
161 /* lux is the integer of sample output multiplied by 0.045. */
162 val->val1 = (uval * 45U) / 1000;
163 val->val2 = ((uval * 45U) % 1000) * 1000U;
164
165 return 0;
166 }
167
168 static const struct sensor_driver_api max44009_driver_api = {
169 .attr_set = max44009_attr_set,
170 .sample_fetch = max44009_sample_fetch,
171 .channel_get = max44009_channel_get,
172 };
173
max44009_init(const struct device * dev)174 int max44009_init(const struct device *dev)
175 {
176 const struct max44009_config *config = dev->config;
177
178 if (!device_is_ready(config->i2c.bus)) {
179 LOG_ERR("Bus device is not ready");
180 return -ENODEV;
181 }
182
183 return 0;
184 }
185
186 #define MAX44009_DEFINE(inst) \
187 static struct max44009_data max44009_data_##inst; \
188 \
189 static const struct max44009_config max44009_config_##inst = { \
190 .i2c = I2C_DT_SPEC_INST_GET(inst), \
191 }; \
192 \
193 SENSOR_DEVICE_DT_INST_DEFINE(inst, max44009_init, NULL, \
194 &max44009_data_##inst, &max44009_config_##inst, POST_KERNEL, \
195 CONFIG_SENSOR_INIT_PRIORITY, &max44009_driver_api); \
196
197 DT_INST_FOREACH_STATUS_OKAY(MAX44009_DEFINE)
198
