From ffd96868ac5d4c22bba1ba2175d124cb2775f3f7 Mon Sep 17 00:00:00 2001 From: Dan Robertson Date: Thu, 5 Sep 2019 01:45:53 +0000 Subject: [PATCH] hwmon: (shtc1) add support for the SHTC3 sensor Add support for the Sensirion SHTC3 humidity and temperature sensor to the shtc1 module. Signed-off-by: Dan Robertson Link: https://lore.kernel.org/r/20190905014554.21658-2-dan@dlrobertson.com Signed-off-by: Guenter Roeck --- Documentation/hwmon/shtc1.rst | 19 +++++++++--- drivers/hwmon/Kconfig | 4 +-- drivers/hwmon/shtc1.c | 57 ++++++++++++++++++++++++++--------- 3 files changed, 59 insertions(+), 21 deletions(-) diff --git a/Documentation/hwmon/shtc1.rst b/Documentation/hwmon/shtc1.rst index aa116332ba26..9b0f1eee5bf2 100644 --- a/Documentation/hwmon/shtc1.rst +++ b/Documentation/hwmon/shtc1.rst @@ -19,7 +19,17 @@ Supported chips: Addresses scanned: none - Datasheet: Not publicly available + Datasheet: http://www.sensirion.com/file/datasheet_shtw1 + + + + * Sensirion SHTC3 + + Prefix: 'shtc3' + + Addresses scanned: none + + Datasheet: http://www.sensirion.com/file/datasheet_shtc3 @@ -30,10 +40,9 @@ Author: Description ----------- -This driver implements support for the Sensirion SHTC1 chip, a humidity and -temperature sensor. Temperature is measured in degrees celsius, relative -humidity is expressed as a percentage. Driver can be used as well for SHTW1 -chip, which has the same electrical interface. +This driver implements support for the Sensirion SHTC1, SHTW1, and SHTC3 +chips, a humidity and temperature sensor. Temperature is measured in degrees +celsius, relative humidity is expressed as a percentage. The device communicates with the I2C protocol. All sensors are set to I2C address 0x70. See Documentation/i2c/instantiating-devices for methods to diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig index c823b662adc9..2ca5668bdb62 100644 --- a/drivers/hwmon/Kconfig +++ b/drivers/hwmon/Kconfig @@ -1392,8 +1392,8 @@ config SENSORS_SHTC1 tristate "Sensiron humidity and temperature sensors. SHTC1 and compat." depends on I2C help - If you say yes here you get support for the Sensiron SHTC1 and SHTW1 - humidity and temperature sensors. + If you say yes here you get support for the Sensiron SHTC1, SHTW1, + and SHTC3 humidity and temperature sensors. This driver can also be built as a module. If so, the module will be called shtc1. diff --git a/drivers/hwmon/shtc1.c b/drivers/hwmon/shtc1.c index b267cf2a9817..a0078ccede03 100644 --- a/drivers/hwmon/shtc1.c +++ b/drivers/hwmon/shtc1.c @@ -24,19 +24,33 @@ static const unsigned char shtc1_cmd_measure_blocking_lpm[] = { 0x64, 0x58 }; static const unsigned char shtc1_cmd_measure_nonblocking_lpm[] = { 0x60, 0x9c }; /* command for reading the ID register */ -static const unsigned char shtc1_cmd_read_id_reg[] = { 0xef, 0xc8 }; +static const unsigned char shtc1_cmd_read_id_reg[] = { 0xef, 0xc8 }; -/* constants for reading the ID register */ -#define SHTC1_ID 0x07 -#define SHTC1_ID_REG_MASK 0x3f +/* + * constants for reading the ID register + * SHTC1: 0x0007 with mask 0x003f + * SHTW1: 0x0007 with mask 0x003f + * SHTC3: 0x0807 with mask 0x083f + */ +#define SHTC3_ID 0x0807 +#define SHTC3_ID_MASK 0x083f +#define SHTC1_ID 0x0007 +#define SHTC1_ID_MASK 0x003f /* delays for non-blocking i2c commands, both in us */ #define SHTC1_NONBLOCKING_WAIT_TIME_HPM 14400 #define SHTC1_NONBLOCKING_WAIT_TIME_LPM 1000 +#define SHTC3_NONBLOCKING_WAIT_TIME_HPM 12100 +#define SHTC3_NONBLOCKING_WAIT_TIME_LPM 800 #define SHTC1_CMD_LENGTH 2 #define SHTC1_RESPONSE_LENGTH 6 +enum shtcx_chips { + shtc1, + shtc3, +}; + struct shtc1_data { struct i2c_client *client; struct mutex update_lock; @@ -47,6 +61,7 @@ struct shtc1_data { unsigned int nonblocking_wait_time; /* in us */ struct shtc1_platform_data setup; + enum shtcx_chips chip; int temperature; /* 1000 * temperature in dgr C */ int humidity; /* 1000 * relative humidity in %RH */ @@ -157,13 +172,16 @@ static void shtc1_select_command(struct shtc1_data *data) data->command = data->setup.blocking_io ? shtc1_cmd_measure_blocking_hpm : shtc1_cmd_measure_nonblocking_hpm; - data->nonblocking_wait_time = SHTC1_NONBLOCKING_WAIT_TIME_HPM; - + data->nonblocking_wait_time = (data->chip == shtc1) ? + SHTC1_NONBLOCKING_WAIT_TIME_HPM : + SHTC3_NONBLOCKING_WAIT_TIME_HPM; } else { data->command = data->setup.blocking_io ? shtc1_cmd_measure_blocking_lpm : shtc1_cmd_measure_nonblocking_lpm; - data->nonblocking_wait_time = SHTC1_NONBLOCKING_WAIT_TIME_LPM; + data->nonblocking_wait_time = (data->chip == shtc1) ? + SHTC1_NONBLOCKING_WAIT_TIME_LPM : + SHTC3_NONBLOCKING_WAIT_TIME_LPM; } } @@ -171,9 +189,11 @@ static int shtc1_probe(struct i2c_client *client, const struct i2c_device_id *id) { int ret; - char id_reg[2]; + u16 id_reg; + char id_reg_buf[2]; struct shtc1_data *data; struct device *hwmon_dev; + enum shtcx_chips chip = id->driver_data; struct i2c_adapter *adap = client->adapter; struct device *dev = &client->dev; @@ -187,13 +207,20 @@ static int shtc1_probe(struct i2c_client *client, dev_err(dev, "could not send read_id_reg command: %d\n", ret); return ret < 0 ? ret : -ENODEV; } - ret = i2c_master_recv(client, id_reg, sizeof(id_reg)); - if (ret != sizeof(id_reg)) { + ret = i2c_master_recv(client, id_reg_buf, sizeof(id_reg_buf)); + if (ret != sizeof(id_reg_buf)) { dev_err(dev, "could not read ID register: %d\n", ret); return -ENODEV; } - if ((id_reg[1] & SHTC1_ID_REG_MASK) != SHTC1_ID) { - dev_err(dev, "ID register doesn't match\n"); + + id_reg = be16_to_cpup((__be16 *)id_reg_buf); + if (chip == shtc3) { + if ((id_reg & SHTC3_ID_MASK) != SHTC3_ID) { + dev_err(dev, "SHTC3 ID register does not match\n"); + return -ENODEV; + } + } else if ((id_reg & SHTC1_ID_MASK) != SHTC1_ID) { + dev_err(dev, "SHTC1 ID register does not match\n"); return -ENODEV; } @@ -204,6 +231,7 @@ static int shtc1_probe(struct i2c_client *client, data->setup.blocking_io = false; data->setup.high_precision = true; data->client = client; + data->chip = chip; if (client->dev.platform_data) data->setup = *(struct shtc1_platform_data *)dev->platform_data; @@ -222,8 +250,9 @@ static int shtc1_probe(struct i2c_client *client, /* device ID table */ static const struct i2c_device_id shtc1_id[] = { - { "shtc1", 0 }, - { "shtw1", 0 }, + { "shtc1", shtc1 }, + { "shtw1", shtc1 }, + { "shtc3", shtc3 }, { } }; MODULE_DEVICE_TABLE(i2c, shtc1_id);