| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Tiberiu Breana | 1098 | 95.81% | 2 | 22.22% |
| Jonathan Cameron | 26 | 2.27% | 1 | 11.11% |
| Chuhong Yuan | 11 | 0.96% | 1 | 11.11% |
| Javier Martinez Canillas | 7 | 0.61% | 1 | 11.11% |
| Gwendal Grignou | 1 | 0.09% | 1 | 11.11% |
| Uwe Kleine-König | 1 | 0.09% | 1 | 11.11% |
| Thomas Gleixner | 1 | 0.09% | 1 | 11.11% |
| Alison Schofield | 1 | 0.09% | 1 | 11.11% |
| Total | 1146 | 9 |
// SPDX-License-Identifier: GPL-2.0-only /* * Aosong AM2315 relative humidity and temperature * * Copyright (c) 2016, Intel Corporation. * * 7-bit I2C address: 0x5C. */ #include <linux/delay.h> #include <linux/i2c.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/iio/buffer.h> #include <linux/iio/iio.h> #include <linux/iio/sysfs.h> #include <linux/iio/trigger_consumer.h> #include <linux/iio/triggered_buffer.h> #define AM2315_REG_HUM_MSB 0x00 #define AM2315_REG_HUM_LSB 0x01 #define AM2315_REG_TEMP_MSB 0x02 #define AM2315_REG_TEMP_LSB 0x03 #define AM2315_FUNCTION_READ 0x03 #define AM2315_HUM_OFFSET 2 #define AM2315_TEMP_OFFSET 4 #define AM2315_ALL_CHANNEL_MASK GENMASK(1, 0) #define AM2315_DRIVER_NAME "am2315" struct am2315_data { struct i2c_client *client; struct mutex lock; /* Ensure timestamp is naturally aligned */ struct { s16 chans[2]; s64 timestamp __aligned(8); } scan; }; struct am2315_sensor_data { s16 hum_data; s16 temp_data; }; static const struct iio_chan_spec am2315_channels[] = { { .type = IIO_HUMIDITYRELATIVE, .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE), .scan_index = 0, .scan_type = { .sign = 's', .realbits = 16, .storagebits = 16, .endianness = IIO_CPU, }, }, { .type = IIO_TEMP, .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE), .scan_index = 1, .scan_type = { .sign = 's', .realbits = 16, .storagebits = 16, .endianness = IIO_CPU, }, }, IIO_CHAN_SOFT_TIMESTAMP(2), }; /* CRC calculation algorithm, as specified in the datasheet (page 13). */ static u16 am2315_crc(u8 *data, u8 nr_bytes) { int i; u16 crc = 0xffff; while (nr_bytes--) { crc ^= *data++; for (i = 0; i < 8; i++) { if (crc & 0x01) { crc >>= 1; crc ^= 0xA001; } else { crc >>= 1; } } } return crc; } /* Simple function that sends a few bytes to the device to wake it up. */ static void am2315_ping(struct i2c_client *client) { i2c_smbus_read_byte_data(client, AM2315_REG_HUM_MSB); } static int am2315_read_data(struct am2315_data *data, struct am2315_sensor_data *sensor_data) { int ret; /* tx_buf format: <function code> <start addr> <nr of regs to read> */ u8 tx_buf[3] = { AM2315_FUNCTION_READ, AM2315_REG_HUM_MSB, 4 }; /* * rx_buf format: * <function code> <number of registers read> * <humidity MSB> <humidity LSB> <temp MSB> <temp LSB> * <CRC LSB> <CRC MSB> */ u8 rx_buf[8]; u16 crc; /* First wake up the device. */ am2315_ping(data->client); mutex_lock(&data->lock); ret = i2c_master_send(data->client, tx_buf, sizeof(tx_buf)); if (ret < 0) { dev_err(&data->client->dev, "failed to send read request\n"); goto exit_unlock; } /* Wait 2-3 ms, then read back the data sent by the device. */ usleep_range(2000, 3000); /* Do a bulk data read, then pick out what we need. */ ret = i2c_master_recv(data->client, rx_buf, sizeof(rx_buf)); if (ret < 0) { dev_err(&data->client->dev, "failed to read sensor data\n"); goto exit_unlock; } mutex_unlock(&data->lock); /* * Do a CRC check on the data and compare it to the value * calculated by the device. */ crc = am2315_crc(rx_buf, sizeof(rx_buf) - 2); if ((crc & 0xff) != rx_buf[6] || (crc >> 8) != rx_buf[7]) { dev_err(&data->client->dev, "failed to verify sensor data\n"); return -EIO; } sensor_data->hum_data = (rx_buf[AM2315_HUM_OFFSET] << 8) | rx_buf[AM2315_HUM_OFFSET + 1]; sensor_data->temp_data = (rx_buf[AM2315_TEMP_OFFSET] << 8) | rx_buf[AM2315_TEMP_OFFSET + 1]; return ret; exit_unlock: mutex_unlock(&data->lock); return ret; } static irqreturn_t am2315_trigger_handler(int irq, void *p) { int i; int ret; int bit; struct iio_poll_func *pf = p; struct iio_dev *indio_dev = pf->indio_dev; struct am2315_data *data = iio_priv(indio_dev); struct am2315_sensor_data sensor_data; ret = am2315_read_data(data, &sensor_data); if (ret < 0) goto err; mutex_lock(&data->lock); if (*(indio_dev->active_scan_mask) == AM2315_ALL_CHANNEL_MASK) { data->scan.chans[0] = sensor_data.hum_data; data->scan.chans[1] = sensor_data.temp_data; } else { i = 0; for_each_set_bit(bit, indio_dev->active_scan_mask, indio_dev->masklength) { data->scan.chans[i] = (bit ? sensor_data.temp_data : sensor_data.hum_data); i++; } } mutex_unlock(&data->lock); iio_push_to_buffers_with_timestamp(indio_dev, &data->scan, pf->timestamp); err: iio_trigger_notify_done(indio_dev->trig); return IRQ_HANDLED; } static int am2315_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long mask) { int ret; struct am2315_sensor_data sensor_data; struct am2315_data *data = iio_priv(indio_dev); switch (mask) { case IIO_CHAN_INFO_RAW: ret = am2315_read_data(data, &sensor_data); if (ret < 0) return ret; *val = (chan->type == IIO_HUMIDITYRELATIVE) ? sensor_data.hum_data : sensor_data.temp_data; return IIO_VAL_INT; case IIO_CHAN_INFO_SCALE: *val = 100; return IIO_VAL_INT; } return -EINVAL; } static const struct iio_info am2315_info = { .read_raw = am2315_read_raw, }; static int am2315_probe(struct i2c_client *client) { int ret; struct iio_dev *indio_dev; struct am2315_data *data; indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); if (!indio_dev) { dev_err(&client->dev, "iio allocation failed!\n"); return -ENOMEM; } data = iio_priv(indio_dev); data->client = client; i2c_set_clientdata(client, indio_dev); mutex_init(&data->lock); indio_dev->info = &am2315_info; indio_dev->name = AM2315_DRIVER_NAME; indio_dev->modes = INDIO_DIRECT_MODE; indio_dev->channels = am2315_channels; indio_dev->num_channels = ARRAY_SIZE(am2315_channels); ret = devm_iio_triggered_buffer_setup(&client->dev, indio_dev, iio_pollfunc_store_time, am2315_trigger_handler, NULL); if (ret < 0) { dev_err(&client->dev, "iio triggered buffer setup failed\n"); return ret; } return devm_iio_device_register(&client->dev, indio_dev); } static const struct i2c_device_id am2315_i2c_id[] = { {"am2315", 0}, {} }; MODULE_DEVICE_TABLE(i2c, am2315_i2c_id); static struct i2c_driver am2315_driver = { .driver = { .name = "am2315", }, .probe = am2315_probe, .id_table = am2315_i2c_id, }; module_i2c_driver(am2315_driver); MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>"); MODULE_DESCRIPTION("Aosong AM2315 relative humidity and temperature"); MODULE_LICENSE("GPL v2");
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