On Fri, Jul 21, 2023 at 12:05:19PM +0200, werneazc@xxxxxxxxx wrote: > From: Andre Werner <andre.werner@xxxxxxxxxxxxxxxxxxxxx> > > Add base support for Renesas HS3001 temperature > and humidity sensors and its compatibles HS3002, > HS3003 and HS3004. > > The sensor has a fix I2C address 0x44. The resolution > is fixed to 14bit (ref. Missing feature). > > Missing feature: > - Accessing non-volatile memory: Custom board has no > possibility to control voltage supply of sensor. Thus, > we cannot send the necessary control commands within > the first 10ms after power-on. > > Signed-off-by: Andre Werner <andre.werner@xxxxxxxxxxxxxxxxxxxxx> > > --- > Changelog: > v1: Initial version > v2: Extensive refactoring following recommendations of reviewers: > - Delete unused defines and device properties. These are added in > the initial version because the device supports a programming mode, > but I was not able to implement it, because the custom board was > not able to control the power supply of the device and so I cannot > enter the programming mode of the device. > - Correct misunderstanding comments for defines. > - Delete mutexes for data and I2C bus accesses. > - Replace attributes with recommended chip-info structure. In the > initial version I followed the sth3x.c implementation that uses > files and attributes in sysfs. The show functions are replaced by > is_visible and read callbacks from the HWMON ABI. I also delete pointless > function argument checks. > - Correct Yoda programming. > - Refactor probe function and delete sleep and measurement of humidity > and temperature in probe function. I kept an initial I2C > communication to ensure that the device is accessible during probe. > - Reduce the number of attributes to humidity and temperature input. > v3: Delete chip data because it is unused. > v4: Refactor driver as follows: > - Delete further unused defines > - Replace masks and operations with GENMASK and FIELD_GET macros > - Add mutex to protect chip wakeup and data transfer operations on bus > - Reformat driver as requested > - Make hs3001_is_visible and hs3001_read function static > --- > Documentation/hwmon/hs3001.rst | 37 +++++ > MAINTAINERS | 6 + > drivers/hwmon/Kconfig | 10 ++ > drivers/hwmon/Makefile | 1 + > drivers/hwmon/hs3001.c | 250 +++++++++++++++++++++++++++++++++ > 5 files changed, 304 insertions(+) > create mode 100644 Documentation/hwmon/hs3001.rst > create mode 100644 drivers/hwmon/hs3001.c > > diff --git a/Documentation/hwmon/hs3001.rst b/Documentation/hwmon/hs3001.rst > new file mode 100644 > index 000000000000..703fb9c45313 > --- /dev/null > +++ b/Documentation/hwmon/hs3001.rst > @@ -0,0 +1,37 @@ > +.. SPDX-License-Identifier: GPL-2.0-or-later > + > +Kernel driver HS3001 > +=================== > + > +Supported chips: > + > + * Renesas HS3001, HS3002, HS3003, HS3004 > + > + Prefix: 'hs3001' > + > + Addresses scanned: - > + > + Datasheet: https://www.renesas.com/us/en/document/dst/hs300x-datasheet?r=417401 > + > +Author: > + > + - Andre Werner <andre.werner@xxxxxxxxxxxxxxxxxxxxx> > + > +Description > +----------- > + > +This driver implements support for the Renesas HS3001 chips, a humidity > +and temperature family. Temperature is measured in degrees celsius, relative > +humidity is expressed as a percentage. In the sysfs interface, all values are > +scaled by 1000, i.e. the value for 31.5 degrees celsius is 31500. > + > +The device communicates with the I2C protocol. Sensors have the I2C > +address 0x44 by default. > + > +sysfs-Interface > +--------------- > + > +=============================================================================== > +temp1_input: temperature input > +humidity1_input: humidity input > +=============================================================================== > diff --git a/MAINTAINERS b/MAINTAINERS > index aee340630eca..25d5282b43aa 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -9494,6 +9494,12 @@ S: Maintained > W: http://artax.karlin.mff.cuni.cz/~mikulas/vyplody/hpfs/index-e.cgi > F: fs/hpfs/ > > +HS3001 Hardware Temperature and Humidity Sensor > +M: Andre Werner <andre.werner@xxxxxxxxxxxxxxxxxxxxx> > +L: linux-hwmon@xxxxxxxxxxxxxxx > +S: Maintained > +F: drivers/hwmon/hs3001.c > + > HSI SUBSYSTEM > M: Sebastian Reichel <sre@xxxxxxxxxx> > S: Maintained > diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig > index 307477b8a371..ca6be5a23271 100644 > --- a/drivers/hwmon/Kconfig > +++ b/drivers/hwmon/Kconfig > @@ -734,6 +734,16 @@ config SENSORS_HIH6130 > This driver can also be built as a module. If so, the module > will be called hih6130. > > +config SENSORS_HS3001 > + tristate "Renesas HS3001 humidity and temperature sensors" > + depends on I2C > + help > + If you say yes here you get support for the Renesas HS3001, > + to HS3004 humidity and temperature sensors. > + > + This driver can also be built as a module. If so, the module > + will be called hs3001. > + > config SENSORS_IBMAEM > tristate "IBM Active Energy Manager temperature/power sensors and control" > select IPMI_SI > diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile > index 3f4b0fda0998..cdae4e1fc919 100644 > --- a/drivers/hwmon/Makefile > +++ b/drivers/hwmon/Makefile > @@ -86,6 +86,7 @@ obj-$(CONFIG_SENSORS_GSC) += gsc-hwmon.o > obj-$(CONFIG_SENSORS_GPIO_FAN) += gpio-fan.o > obj-$(CONFIG_SENSORS_GXP_FAN_CTRL) += gxp-fan-ctrl.o > obj-$(CONFIG_SENSORS_HIH6130) += hih6130.o > +obj-$(CONFIG_SENSORS_HS3001) += hs3001.o > obj-$(CONFIG_SENSORS_ULTRA45) += ultra45_env.o > obj-$(CONFIG_SENSORS_I5500) += i5500_temp.o > obj-$(CONFIG_SENSORS_I5K_AMB) += i5k_amb.o > diff --git a/drivers/hwmon/hs3001.c b/drivers/hwmon/hs3001.c > new file mode 100644 > index 000000000000..483b47c81b83 > --- /dev/null > +++ b/drivers/hwmon/hs3001.c > @@ -0,0 +1,250 @@ > +// SPDX-License-Identifier: GPL-2.0-or-later > +/* > + * This is a non-complete driver implementation for the > + * HS3001 humidity and temperature sensor and compatibles. It does not include > + * the configuration possibilities, where it needs to be set to 'programming mode' > + * during power-up. > + * > + * > + * Copyright (C) 2023 SYS TEC electronic AG > + * Author: Andre Werner <andre.werner@xxxxxxxxxxxxxxxxxxxxx> > + */ > + > +#include <linux/bitfield.h> > +#include <linux/delay.h> > +#include <linux/err.h> > +#include <linux/hwmon.h> > +#include <linux/i2c.h> > +#include <linux/init.h> > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/of_device.h> > +#include <linux/slab.h> > +#include <linux/types.h> > + > +/* Measurement times */ > +#define HS3001_WAKEUP_TIME 100 /* us */ > +#define HS3001_8BIT_RESOLUTION 550 /* us */ > +#define HS3001_10BIT_RESOLUTION 1310 /* us */ > +#define HS3001_12BIT_RESOLUTION 4500 /* us */ > +#define HS3001_14BIT_RESOLUTION 16900 /* us */ > + > +#define HS3001_RESPONSE_LENGTH 4 > + > +#define HS3001_FIXPOINT_ARITH 1000U > + > +#define HS3001_MASK_HUMIDITY_0X3FFF GENMASK(13, 0) > +#define HS3001_MASK_STATUS_0XC0 GENMASK(7, 6) > + > +/* Definitions for Status Bits of A/D Data */ > +#define HS3001_DATA_VALID 0x00 /* Valid Data */ > +#define HS3001_DATA_STALE 0x01 /* Stale Data */ > + > +struct hs3001_data { > + struct i2c_client *client; > + struct mutex i2c_lock; /* lock for sending i2c commands */ > + u32 wait_time; /* in us */ > + int temperature; /* in milli degree */ > + u32 humidity; /* in milli % */ > +}; > + > +static int hs3001_extract_temperature(u16 raw) > +{ > + /* fixpoint arithmetic 1 digit */ > + int temp = (raw >> 2) * HS3001_FIXPOINT_ARITH; > + > + temp /= (1 << 14) - 1; > + > + return temp * 165 - 40 * HS3001_FIXPOINT_ARITH; This code results in unnecessary precision loss. Code such as unsigned int temp = (raw >> 2) * HS3001_FIXPOINT_ARITH * 165; temp /= (1 << 14) - 1; return (int)temp - 40 * HS3001_FIXPOINT_ARITH; would be functionally identical and avoid the precision loss. > +} > + > +static u32 hs3001_extract_humidity(u16 raw) > +{ > + u32 hum = (raw & HS3001_MASK_HUMIDITY_0X3FFF) * HS3001_FIXPOINT_ARITH; > + > + hum /= (1 << 14) - 1; > + > + return hum * 100; This code results in unnecessary precision loss. Code such as u32 hum = (raw & HS3001_MASK_HUMIDITY_0X3FFF) * HS3001_FIXPOINT_ARITH * 100; return hum / (1 << 14) - 1; would be functionally identical and avoid the precision loss. If you explicitly _want_ the precision loss in those functions, please add comments explaining the reason. > +} > + > +static int hs3001_data_fetch_command(struct i2c_client *client, > + struct hs3001_data *data) > +{ > + int ret; > + u8 buf[HS3001_RESPONSE_LENGTH]; > + u8 hs3001_status; > + > + ret = i2c_master_recv(client, buf, HS3001_RESPONSE_LENGTH); > + if (ret != HS3001_RESPONSE_LENGTH) { > + ret = ret < 0 ? ret : -EIO; > + dev_dbg(&client->dev, > + "Error in i2c communication. Error code: %d.\n", ret); > + return ret; > + } > + > + hs3001_status = FIELD_GET(HS3001_MASK_STATUS_0XC0, buf[0]); > + if (hs3001_status == HS3001_DATA_STALE) { > + dev_dbg(&client->dev, "Sensor busy.\n"); > + return -EBUSY; > + } > + if (hs3001_status != HS3001_DATA_VALID) { > + dev_dbg(&client->dev, "Data invalid.\n"); > + return -EIO; > + } > + > + data->humidity = > + hs3001_extract_humidity(be16_to_cpup((__be16 *)&buf[0])); > + data->temperature = > + hs3001_extract_temperature(be16_to_cpup((__be16 *)&buf[2])); > + > + return 0; > +} > + > +static umode_t hs3001_is_visible(const void *data, enum hwmon_sensor_types type, > + u32 attr, int channel) > +{ > + /* Both, humidity and temperature can only be read. */ > + return 0444; > +} > + > +static int hs3001_read(struct device *dev, enum hwmon_sensor_types type, > + u32 attr, int channel, long *val) > +{ > + struct hs3001_data *data = dev_get_drvdata(dev); > + struct i2c_client *client = data->client; > + int ret; > + > + /* Protected section beginn */ > + mutex_lock(&data->i2c_lock); > + ret = i2c_master_send(client, NULL, 0); > + if (ret < 0) > + return ret; > + > + /* > + * Sensor needs some time to process measurement depending on > + * resolution (ref. datasheet) > + */ > + fsleep(data->wait_time); > + > + ret = hs3001_data_fetch_command(client, data); > + mutex_unlock(&data->i2c_lock); > + /* Protected section end */ > + > + if (ret < 0) > + return ret; > + > + switch (type) { > + case hwmon_temp: > + switch (attr) { > + case hwmon_temp_input: > + *val = data->temperature; > + break; > + default: > + return -EINVAL; > + } > + break; > + case hwmon_humidity: > + switch (attr) { > + case hwmon_humidity_input: > + *val = data->humidity; > + break; > + default: > + return -EINVAL; > + } > + break; > + default: > + return -EINVAL; > + } > + > + return 0; > +} > + > +static const struct hwmon_channel_info *hs3001_info[] = { > + HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT), > + HWMON_CHANNEL_INFO(humidity, HWMON_H_INPUT), > + NULL > +}; > + > +static const struct hwmon_ops hs3001_hwmon_ops = { > + .is_visible = hs3001_is_visible, > + .read = hs3001_read, > +}; > + > +static const struct hwmon_chip_info hs3001_chip_info = { > + .ops = &hs3001_hwmon_ops, > + .info = hs3001_info, > +}; > + > +/* device ID table */ > +static const struct i2c_device_id hs3001_ids[] = { > + { "hs3001", 0 }, > + { }, > +}; > + > +MODULE_DEVICE_TABLE(i2c, hs3001_ids); > + > +static const struct of_device_id hs3001_of_match[] = { > + {.compatible = "renesas,hs3001"}, > + { }, > +}; > + > +MODULE_DEVICE_TABLE(of, hs3001_of_match); > + > +static int hs3001_probe(struct i2c_client *client) > +{ > + struct hs3001_data *data; > + struct device *hwmon_dev; > + struct device *dev = &client->dev; > + int ret; > + > + if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) > + return -EOPNOTSUPP; > + > + data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); > + if (!data) > + return -ENOMEM; > + > + data->client = client; > + > + /* > + * Measurement time = wake-up time + measurement time temperature > + * + measurment time humidity. This is currently static, because > + * enabling programming mode is not supported, yet. > + */ > + data->wait_time = (HS3001_WAKEUP_TIME + HS3001_14BIT_RESOLUTION + > + HS3001_14BIT_RESOLUTION); > + > + mutex_init(&data->i2c_lock); > + > + /* Test access to device */ > + ret = i2c_master_send(client, NULL, 0); > + if (ret) > + return ret; Again, this code only checks if a device is there, not that a HS300{1,2,3,4} is there. It does not add any value, we don't do this for other chips, and I won't accept this kind of code. Please drop. Guenter > + > + hwmon_dev = devm_hwmon_device_register_with_info(dev, > + client->name, > + data, > + &hs3001_chip_info, > + NULL); > + > + if (IS_ERR(hwmon_dev)) > + return dev_err_probe(dev, PTR_ERR(hwmon_dev), > + "Unable to register hwmon device.\n"); > + > + return 0; > +} > + > +static struct i2c_driver hs3001_i2c_driver = { > + .driver = { > + .name = "hs3001", > + .of_match_table = hs3001_of_match, > + }, > + .probe_new = hs3001_probe, > + .id_table = hs3001_ids, > +}; > + > +module_i2c_driver(hs3001_i2c_driver); > + > +MODULE_AUTHOR("Andre Werner <andre.werner@xxxxxxxxxxxxxxxxxxxxx>"); > +MODULE_DESCRIPTION("HS3001 humidity and temperature sensor base driver"); > +MODULE_LICENSE("GPL"); > -- > 2.41.0 >
