[PATCH v6 5/5] hwmon: Add support for Amphenol ChipCap 2

Javier Carrasco
2024-01-30T21:06:58Z

The Amphenol ChipCap 2 is a capacitive polymer humidity and temperature
sensor with an integrated EEPROM and minimum/maximum humidity alarms.

All device variants offer an I2C interface and depending on the part
number, two different output modes:
- CC2D: digital output
- CC2A: analog (PDM) output

This driver adds support for the digital variant (CC2D part numbers),
which includes the following part numbers:
- non-sleep measurement mode (CC2D23, CC2D25, CC2D33, CC2D35)
- sleep measurement mode (CC2D23S, CC2D25S, CC2D33S, CC2D35S)

The Chipcap 2 EEPROM can be accessed to configure a series of parameters
like the minimum/maximum humidity alarm threshold and hysteresis. The
EEPROM is only accessible in the command window after a power-on reset.
The default window lasts 10 ms if no Start_CM command is sent. After the
command window is finished (either after the mentioned timeout of after
a Start_NOM command is sent), the device enters the normal operation
mode and makes a first measurement automatically.

Unfortunately, the device does not provide any hardware or software
reset and therefore the driver must trigger power cycles to enter the
command mode. A dedicated, external regulator is required for that.

This driver keeps the device off until a measurement or access to the
EEPROM is required, making use of the first automatic measurement to
avoid different code paths for sleep and non-sleep devices.

The minimum and maximum humidity alarms are configured with two
registers per alarm: one stores the alarm threshold and the other one
keeps the value that turns off the alarm. The alarm signals are only
updated when a measurement is carried out.

Signed-off-by: Javier Carrasco <javier.carrasco.cruz@gmail.com>
---
Documentation/hwmon/chipcap2.rst | 73 ++++
Documentation/hwmon/index.rst | 1 +
MAINTAINERS | 8 +
drivers/hwmon/Kconfig | 10 +
drivers/hwmon/Makefile | 1 +
drivers/hwmon/chipcap2.c | 816 +++++++++++++++++++++++++++++++++++++++
6 files changed, 909 insertions(+)

diff --git a/Documentation/hwmon/chipcap2.rst b/Documentation/hwmon/chipcap2.rst
new file mode 100644
index 000000000000..dc165becc64c
--- /dev/null
+++ b/Documentation/hwmon/chipcap2.rst
@@ -0,0 +1,73 @@
+.. SPDX-License-Identifier: GPL-2.0-or-later
+
+Kernel driver ChipCap2
+======================
+
+Supported chips:
+
+ * Amphenol CC2D23, CC2D23S, CC2D25, CC2D25S, CC2D33, CC2D33S, CC2D35, CC2D35S
+
+ Prefix: 'chipcap2'
+
+ Addresses scanned: -
+
+ Datasheet: https://www.amphenol-sensors.com/en/telaire/humidity/527-humidity-sensors/3095-chipcap-2
+
+Author:
+
+ - Javier Carrasco <javier.carrasco.cruz@gmail.com>
+
+Description
+-----------
+
+This driver implements support for the Amphenol ChipCap 2, a humidity and
+temperature chip family. Temperature is measured in milli degrees celsius,
+relative humidity is expressed as a per cent mille. The measurement ranges
+are the following:
+
+ - Relative humidity: 0 to 100000 pcm (14-bit resolution)
+ - Temperature: -40000 to +125000 m°C (14-bit resolution)
+
+The device communicates with the I2C protocol and uses the I2C address 0x28
+by default.
+
+Depending on the hardware configuration, up to two humidity alarms to control
+minimum and maximum values are provided. Their thresholds and hystersis can be
+configured via sysfs.
+
+Thresholds and hysteris must be provided as a per cent mille. These values
+might be truncated to match the 14-bit device resolution (6.1 pcm/LSB)
+
+Known Issues
+------------
+
+The driver does not support I2C address and command window length modification.
+
+sysfs-Interface
+---------------
+
+The following list includes the sysfs attributes that the driver always provides,
+their permissions and a short description:
+
+=============================== ======= ========================================
+Name Perm Description
+=============================== ======= ========================================
+temp1_input: RO temperature input
+humidity1_input: RO humidity input
+=============================== ======= ========================================
+
+The following list includes the sysfs attributes that the driver may provide
+depending on the hardware configuration:
+
+=============================== ======= ========================================
+Name Perm Description
+=============================== ======= ========================================
+humidity1_min: RW humidity low limit. Measurements under
+ this limit trigger a humidity low alarm
+humidity1_max: RW humidity high limit. Measurements above
+ this limit trigger a humidity high alarm
+humidity1_min_hyst: RW humidity low hystersis
+humidity1_max_hyst: RW humidity high hystersis
+humidity1_min_alarm: RO humidity low alarm indicator
+humidity1_max_alarm: RO humidity high alarm indicator
+=============================== ======= ========================================
diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst
index c7ed1f73ac06..99ba35f47868 100644
--- a/Documentation/hwmon/index.rst
+++ b/Documentation/hwmon/index.rst
@@ -51,6 +51,7 @@ Hardware Monitoring Kernel Drivers
bel-pfe
bpa-rs600
bt1-pvt
+ chipcap2
coretemp
corsair-cpro
corsair-psu
diff --git a/MAINTAINERS b/MAINTAINERS
index 8d1052fa6a69..e70231735f71 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1098,6 +1098,14 @@ F: Documentation/devicetree/bindings/perf/amlogic,g12-ddr-pmu.yaml
F: drivers/perf/amlogic/
F: include/soc/amlogic/

+AMPHENOL CHIPCAP 2 HUMIDITY-TEMPERATURE IIO DRIVER
+M: Javier Carrasco <javier.carrasco.cruz@gmail.com>
+L: linux-hwmon@vger.kernel.org
+S: Maintained
+F: Documentation/devicetree/bindings/hwmon/amphenol,chipcap2.yaml
+F: Documentation/hwmon/chipcap2.rst
+F: drivers/hwmon/chipcap2.c
+
AMPHION VPU CODEC V4L2 DRIVER
M: Ming Qian <ming.qian@nxp.com>
M: Zhou Peng <eagle.zhou@nxp.com>
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index a608264da87d..cb38f30411f7 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -452,6 +452,16 @@ config SENSORS_BT1_PVT_ALARMS
the data conversion will be periodically performed and the data will be
saved in the internal driver cache.

+config SENSORS_CHIPCAP2
+ tristate "Amphenol ChipCap 2 relative humidity and temperature sensor"
+ depends on I2C
+ help
+ Say yes here to build support for the Amphenol ChipCap 2
+ relative humidity and temperature sensor.
+
+ To compile this driver as a module, choose M here: the module
+ will be called chipcap2.
+
config SENSORS_CORSAIR_CPRO
tristate "Corsair Commander Pro controller"
depends on HID
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 47be39af5c03..1ea4f42630fb 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -58,6 +58,7 @@ obj-$(CONFIG_SENSORS_ASPEED) += aspeed-pwm-tacho.o
obj-$(CONFIG_SENSORS_ATXP1) += atxp1.o
obj-$(CONFIG_SENSORS_AXI_FAN_CONTROL) += axi-fan-control.o
obj-$(CONFIG_SENSORS_BT1_PVT) += bt1-pvt.o
+obj-$(CONFIG_SENSORS_CHIPCAP2) += chipcap2.o
obj-$(CONFIG_SENSORS_CORETEMP) += coretemp.o
obj-$(CONFIG_SENSORS_CORSAIR_CPRO) += corsair-cpro.o
obj-$(CONFIG_SENSORS_CORSAIR_PSU) += corsair-psu.o
diff --git a/drivers/hwmon/chipcap2.c b/drivers/hwmon/chipcap2.c
new file mode 100644
index 000000000000..a62c507b1042
--- /dev/null
+++ b/drivers/hwmon/chipcap2.c
@@ -0,0 +1,816 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * cc2.c - Support for the Amphenol ChipCap 2 relative humidity, temperature sensor
+ *
+ * Part numbers supported:
+ * CC2D23, CC2D23S, CC2D25, CC2D25S, CC2D33, CC2D33S, CC2D35, CC2D35S
+ *
+ * Author: Javier Carrasco <javier.carrasco.cruz@gmail.com>
+ *
+ * Datasheet and application notes:
+ * https://www.amphenol-sensors.com/en/telaire/humidity/527-humidity-sensors/3095-chipcap-2
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/hwmon.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/module.h>
+#include <linux/regulator/consumer.h>
+
+#define CC2_START_CM 0xA0
+#define CC2_START_NOM 0x80
+#define CC2_R_ALARM_H_ON 0x18
+#define CC2_R_ALARM_H_OFF 0x19
+#define CC2_R_ALARM_L_ON 0x1A
+#define CC2_R_ALARM_L_OFF 0x1B
+#define CC2_RW_OFFSET 0x40
+#define CC2_W_ALARM_H_ON (CC2_R_ALARM_H_ON + CC2_RW_OFFSET)
+#define CC2_W_ALARM_H_OFF (CC2_R_ALARM_H_OFF + CC2_RW_OFFSET)
+#define CC2_W_ALARM_L_ON (CC2_R_ALARM_L_ON + CC2_RW_OFFSET)
+#define CC2_W_ALARM_L_OFF (CC2_R_ALARM_L_OFF + CC2_RW_OFFSET)
+
+#define CC2_STATUS_FIELD GENMASK(7, 6)
+#define CC2_STATUS_VALID_DATA 0x00
+#define CC2_STATUS_STALE_DATA 0x01
+#define CC2_STATUS_CMD_MODE 0x02
+
+#define CC2_RESPONSE_FIELD GENMASK(1, 0)
+#define CC2_RESPONSE_BUSY 0x00
+#define CC2_RESPONSE_ACK 0x01
+#define CC2_RESPONSE_NACK 0x02
+
+#define CC2_ERR_CORR_EEPROM BIT(2)
+#define CC2_ERR_UNCORR_EEPROM BIT(3)
+#define CC2_ERR_RAM_PARITY BIT(4)
+#define CC2_ERR_CONFIG_LOAD BIT(5)
+
+#define CC2_EEPROM_SIZE 10
+#define CC2_EEPROM_DATA_LEN 3
+#define CC2_MEASUREMENT_DATA_LEN 4
+
+#define CC2_RH_DATA_FIELD GENMASK(13, 0)
+
+/* ensure clean off -> on transitions */
+#define CC2_POWER_CYCLE_MS 80
+
+#define CC2_STARTUP_TO_DATA_MS 55
+#define CC2_RESP_START_CM_US 100
+#define CC2_RESP_EEPROM_R_US 100
+#define CC2_RESP_EEPROM_W_MS 12
+#define CC2_STARTUP_TIME_US 1250
+
+#define CC2_RH_MAX (100 * 1000U)
+
+#define CC2_CM_RETRIES 5
+
+struct cc2_rh_alarm_info {
+ bool low_alarm;
+ bool high_alarm;
+ bool low_alarm_visible;
+ bool high_alarm_visible;
+};
+
+struct cc2_data {
+ struct cc2_rh_alarm_info rh_alarm;
+ struct completion complete;
+ struct device *hwmon;
+ struct i2c_client *client;
+ struct mutex dev_access_lock; /* device access lock */
+ struct regulator *regulator;
+ const char *name;
+ int irq_ready;
+ int irq_low;
+ int irq_high;
+ bool process_irqs;
+};
+
+enum cc2_chan_addr {
+ CC2_CHAN_TEMP = 0,
+ CC2_CHAN_HUMIDITY,
+};
+
+/* %RH as a per cent mille from a register value */
+static long cc2_rh_convert(u16 data)
+{
+ unsigned long tmp = (data & CC2_RH_DATA_FIELD) * CC2_RH_MAX;
+
+ return tmp / ((1 << 14) - 1);
+}
+
+/* convert %RH to a register value */
+static u16 cc2_rh_to_reg(long data)
+{
+ return data * ((1 << 14) - 1) / CC2_RH_MAX;
+}
+
+/* temperature in milli degrees celsius from a register value */
+static long cc2_temp_convert(u16 data)
+{
+ unsigned long tmp = ((data >> 2) * 165 * 1000U) / ((1 << 14) - 1);
+
+ return tmp - 40 * 1000U;
+}
+
+static int cc2_enable(struct cc2_data *data)
+{
+ int ret;
+
+ /* exclusive regulator, check in case a disable failed */
+ if (regulator_is_enabled(data->regulator))
+ return 0;
+
+ /* clear any pending completion */
+ try_wait_for_completion(&data->complete);
+
+ ret = regulator_enable(data->regulator);
+ if (ret < 0)
+ return ret;
+
+ usleep_range(CC2_STARTUP_TIME_US, CC2_STARTUP_TIME_US + 125);
+
+ data->process_irqs = true;
+
+ return 0;
+}
+
+static void cc2_disable(struct cc2_data *data)
+{
+ int err;
+
+ /* ignore alarms triggered by voltage toggling when powering up */
+ data->process_irqs = false;
+
+ /* exclusive regulator, check in case an enable failed */
+ if (regulator_is_enabled(data->regulator)) {
+ err = regulator_disable(data->regulator);
+ if (err)
+ dev_dbg(&data->client->dev, "Failed to disable device");
+ }
+}
+
+static int cc2_cmd_response_diagnostic(struct device *dev, u8 status)
+{
+ int resp;
+
+ if (FIELD_GET(CC2_STATUS_FIELD, status) != CC2_STATUS_CMD_MODE) {
+ dev_dbg(dev, "Command sent out of command window\n");
+ return -ETIMEDOUT;
+ }
+
+ resp = FIELD_GET(CC2_RESPONSE_FIELD, status);
+ switch (resp) {
+ case CC2_RESPONSE_ACK:
+ return 0;
+ case CC2_RESPONSE_BUSY:
+ return -EBUSY;
+ case CC2_RESPONSE_NACK:
+ if (resp & CC2_ERR_CORR_EEPROM)
+ dev_dbg(dev, "Command failed: corrected EEPROM\n");
+ if (resp & CC2_ERR_UNCORR_EEPROM)
+ dev_dbg(dev, "Command failed: uncorrected EEPROM\n");
+ if (resp & CC2_ERR_RAM_PARITY)
+ dev_dbg(dev, "Command failed: RAM parity\n");
+ if (resp & CC2_ERR_RAM_PARITY)
+ dev_dbg(dev, "Command failed: configuration error\n");
+ return -ENODATA;
+ default:
+ dev_dbg(dev, "Unknown command reply\n");
+ return -EINVAL;
+ }
+}
+
+static int cc2_read_command_status(struct i2c_client *client)
+{
+ u8 status;
+ int ret;
+
+ ret = i2c_master_recv(client, &status, 1);
+ if (ret != 1) {
+ ret = ret < 0 ? ret : -EIO;
+ return ret;
+ }
+
+ return cc2_cmd_response_diagnostic(&client->dev, status);
+}
+
+/*
+ * The command mode is only accessible after sending the START_CM command in the
+ * first 10 ms after power-up. Only in case the command window is missed,
+ * CC2_CM_RETRIES retries are attempted before giving up and returning an error.
+ */
+static int cc2_command_mode_start(struct cc2_data *data)
+{
+ unsigned long timeout;
+ int i, ret;
+
+ for (i = 0; i < CC2_CM_RETRIES; i++) {
+ ret = cc2_enable(data);
+ if (ret < 0)
+ return ret;
+
+ ret = i2c_smbus_write_word_data(data->client, CC2_START_CM, 0);
+ if (ret < 0)
+ return ret;
+
+ if (data->irq_ready > 0) {
+ timeout = usecs_to_jiffies(2 * CC2_RESP_START_CM_US);
+ ret = wait_for_completion_timeout(&data->complete,
+ timeout);
+ if (!ret)
+ return -ETIMEDOUT;
+ } else {
+ usleep_range(CC2_RESP_START_CM_US,
+ 2 * CC2_RESP_START_CM_US);
+ }
+ ret = cc2_read_command_status(data->client);
+ if (ret != -ETIMEDOUT || i == CC2_CM_RETRIES)
+ break;
+
+ /* command window missed, prepare for a retry */
+ cc2_disable(data);
+ msleep(CC2_POWER_CYCLE_MS);
+ }
+
+ return ret;
+}
+
+/* Sending a Start_NOM command finishes the command mode immediately with no
+ * reply and the device enters normal operation mode
+ */
+static int cc2_command_mode_finish(struct cc2_data *data)
+{
+ int ret;
+
+ ret = i2c_smbus_write_word_data(data->client, CC2_START_NOM, 0);
+ if (ret < 0)
+ return ret;
+
+ return 0;
+}
+
+static int cc2_write_reg(struct cc2_data *data, u8 reg, u16 val)
+{
+ unsigned long timeout;
+ int ret;
+
+ ret = cc2_command_mode_start(data);
+ if (ret < 0)
+ goto disable;
+
+ cpu_to_be16s(&val);
+ ret = i2c_smbus_write_word_data(data->client, reg, val);
+ if (ret < 0)
+ goto disable;
+
+ if (data->irq_ready > 0) {
+ timeout = msecs_to_jiffies(2 * CC2_RESP_EEPROM_W_MS);
+ ret = wait_for_completion_timeout(&data->complete, timeout);
+ if (!ret) {
+ ret = -ETIMEDOUT;
+ goto disable;
+ }
+ } else {
+ msleep(CC2_RESP_EEPROM_W_MS);
+ }
+
+ ret = cc2_read_command_status(data->client);
+
+disable:
+ cc2_disable(data);
+
+ return ret;
+}
+
+static int cc2_read_reg(struct cc2_data *data, u8 reg, u16 *val)
+{
+ u8 buf[CC2_EEPROM_DATA_LEN];
+ unsigned long timeout;
+ int ret;
+
+ ret = cc2_command_mode_start(data);
+ if (ret < 0)
+ return ret;
+
+ ret = i2c_smbus_write_word_data(data->client, reg, 0);
+ if (ret < 0)
+ return ret;
+
+ if (data->irq_ready > 0) {
+ timeout = usecs_to_jiffies(2 * CC2_RESP_EEPROM_R_US);
+ ret = wait_for_completion_timeout(&data->complete, timeout);
+ if (!ret)
+ return -ETIMEDOUT;
+
+ } else {
+ usleep_range(CC2_RESP_EEPROM_R_US, CC2_RESP_EEPROM_R_US + 10);
+ }
+ ret = i2c_master_recv(data->client, buf, CC2_EEPROM_DATA_LEN);
+ if (ret != CC2_EEPROM_DATA_LEN)
+ return ret < 0 ? ret : -EIO;
+
+ *val = be16_to_cpup((__be16 *)&buf[1]);
+
+ return cc2_read_command_status(data->client);
+}
+
+static int cc2_get_reg_val(struct cc2_data *data, u8 reg, long *val)
+{
+ u16 reg_val;
+ int ret;
+
+ ret = cc2_read_reg(data, reg, &reg_val);
+ *val = cc2_rh_convert(reg_val);
+ cc2_disable(data);
+
+ return ret;
+}
+
+static int cc2_data_fetch(struct i2c_client *client,
+ enum hwmon_sensor_types type, long *val)
+{
+ u8 data[CC2_MEASUREMENT_DATA_LEN];
+ u8 status;
+ int ret;
+
+ ret = i2c_master_recv(client, data, CC2_MEASUREMENT_DATA_LEN);
+ if (ret != CC2_MEASUREMENT_DATA_LEN) {
+ ret = ret < 0 ? ret : -EIO;
+ return ret;
+ }
+ status = FIELD_GET(CC2_STATUS_FIELD, data[0]);
+ if (status == CC2_STATUS_STALE_DATA)
+ return -EBUSY;
+
+ if (status != CC2_STATUS_VALID_DATA)
+ return -EIO;
+
+ switch (type) {
+ case hwmon_humidity:
+ *val = cc2_rh_convert(be16_to_cpup((__be16 *)&data[0]));
+ break;
+ case hwmon_temp:
+ *val = cc2_temp_convert(be16_to_cpup((__be16 *)&data[2]));
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int cc2_read_measurement(struct cc2_data *data,
+ enum hwmon_sensor_types type, long *val)
+{
+ unsigned long timeout;
+ int ret;
+
+ if (data->irq_ready > 0) {
+ timeout = msecs_to_jiffies(CC2_STARTUP_TO_DATA_MS * 2);
+ ret = wait_for_completion_timeout(&data->complete, timeout);
+ if (!ret)
+ return -ETIMEDOUT;
+
+ } else {
+ msleep(CC2_STARTUP_TO_DATA_MS);
+ }
+
+ ret = cc2_data_fetch(data->client, type, val);
+
+ return ret;
+}
+
+/*
+ * A measurement requires enabling the device, waiting for the automatic
+ * measurement to finish, reading the measurement data and disabling the device
+ * again.
+ */
+static int cc2_measurement(struct cc2_data *data, enum hwmon_sensor_types type,
+ long *val)
+{
+ int ret;
+
+ ret = cc2_enable(data);
+ if (ret)
+ return ret;
+
+ ret = cc2_read_measurement(data, type, val);
+
+ cc2_disable(data);
+
+ return ret;
+}
+
+/*
+ * In order to check alarm status, the corresponding ALARM_OFF (hysteresis)
+ * register must be read and a new measurement must be carried out to trigger
+ * the alarm signals. Given that the device carries out a measurement after
+ * exiting the command mode, there is no need to force two power-up sequences.
+ * Instead, a NOM command is sent and the device is disabled after the
+ * measurement is read.
+ */
+static int cc2_read_hyst_and_measure(struct cc2_data *data, u8 reg,
+ long *hyst, long *measurement)
+{
+ u16 reg_val;
+ int ret;
+
+ ret = cc2_read_reg(data, reg, &reg_val);
+ if (ret)
+ goto disable;
+
+ *hyst = cc2_rh_convert(reg_val);
+
+ ret = cc2_command_mode_finish(data);
+ if (ret)
+ goto disable;
+
+ ret = cc2_read_measurement(data, hwmon_humidity, measurement);
+
+disable:
+ cc2_disable(data);
+
+ return ret;
+}
+
+static umode_t cc2_is_visible(const void *data, enum hwmon_sensor_types type,
+ u32 attr, int channel)
+{
+ const struct cc2_data *cc2 = data;
+
+ switch (type) {
+ case hwmon_humidity:
+ switch (attr) {
+ case hwmon_humidity_input:
+ return 0444;
+ case hwmon_humidity_min_alarm:
+ return cc2->rh_alarm.low_alarm_visible ? 0444 : 0;
+ case hwmon_humidity_max_alarm:
+ return cc2->rh_alarm.high_alarm_visible ? 0444 : 0;
+ case hwmon_humidity_min:
+ case hwmon_humidity_min_hyst:
+ return cc2->rh_alarm.low_alarm_visible ? 0644 : 0;
+ case hwmon_humidity_max:
+ case hwmon_humidity_max_hyst:
+ return cc2->rh_alarm.high_alarm_visible ? 0644 : 0;
+ default:
+ return 0;
+ }
+ case hwmon_temp:
+ switch (attr) {
+ case hwmon_temp_input:
+ return 0444;
+ default:
+ return 0;
+ }
+ default:
+ break;
+ }
+
+ return 0;
+}
+
+static irqreturn_t cc2_ready_interrupt(int irq, void *data)
+{
+ struct cc2_data *cc2 = data;
+
+ if (cc2->process_irqs)
+ complete(&cc2->complete);
+
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t cc2_low_interrupt(int irq, void *data)
+{
+ struct cc2_data *cc2 = data;
+
+ if (cc2->process_irqs) {
+ hwmon_notify_event(cc2->hwmon, hwmon_humidity,
+ hwmon_humidity_min_alarm, CC2_CHAN_HUMIDITY);
+ cc2->rh_alarm.low_alarm = true;
+ }
+
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t cc2_high_interrupt(int irq, void *data)
+{
+ struct cc2_data *cc2 = data;
+
+ if (cc2->process_irqs) {
+ hwmon_notify_event(cc2->hwmon, hwmon_humidity,
+ hwmon_humidity_max_alarm, CC2_CHAN_HUMIDITY);
+ cc2->rh_alarm.high_alarm = true;
+ }
+
+ return IRQ_HANDLED;
+}
+
+static int cc2_humidity_min_alarm_status(struct cc2_data *data, long *val)
+{
+ long measurement, min_hyst;
+ int ret;
+
+ ret = cc2_read_hyst_and_measure(data, CC2_R_ALARM_L_OFF, &min_hyst,
+ &measurement);
+ if (ret < 0)
+ return ret;
+
+ if (data->rh_alarm.low_alarm) {
+ *val = (measurement < min_hyst) ? 1 : 0;
+ data->rh_alarm.low_alarm = *val;
+ } else {
+ *val = 0;
+ }
+
+ return 0;
+}
+
+static int cc2_humidity_max_alarm_status(struct cc2_data *data, long *val)
+{
+ long measurement, max_hyst;
+ int ret;
+
+ ret = cc2_read_hyst_and_measure(data, CC2_R_ALARM_H_OFF, &max_hyst,
+ &measurement);
+ if (ret < 0)
+ return ret;
+
+ if (data->rh_alarm.high_alarm) {
+ *val = (measurement > max_hyst) ? 1 : 0;
+ data->rh_alarm.high_alarm = *val;
+ } else {
+ *val = 0;
+ }
+
+ return 0;
+}
+
+static int cc2_read(struct device *dev, enum hwmon_sensor_types type, u32 attr,
+ int channel, long *val)
+{
+ struct cc2_data *data = dev_get_drvdata(dev);
+ int ret = 0;
+
+ mutex_lock(&data->dev_access_lock);
+
+ switch (type) {
+ case hwmon_temp:
+ ret = cc2_measurement(data, type, val);
+ break;
+ case hwmon_humidity:
+ switch (attr) {
+ case hwmon_humidity_input:
+ ret = cc2_measurement(data, type, val);
+ break;
+ case hwmon_humidity_min:
+ ret = cc2_get_reg_val(data, CC2_R_ALARM_L_ON, val);
+ break;
+ case hwmon_humidity_min_hyst:
+ ret = cc2_get_reg_val(data, CC2_R_ALARM_L_OFF, val);
+ break;
+ case hwmon_humidity_max:
+ ret = cc2_get_reg_val(data, CC2_R_ALARM_H_ON, val);
+ break;
+ case hwmon_humidity_max_hyst:
+ ret = cc2_get_reg_val(data, CC2_R_ALARM_H_OFF, val);
+ break;
+ case hwmon_humidity_min_alarm:
+ ret = cc2_humidity_min_alarm_status(data, val);
+ break;
+ case hwmon_humidity_max_alarm:
+ ret = cc2_humidity_max_alarm_status(data, val);
+ break;
+ default:
+ ret = -EOPNOTSUPP;
+ }
+ break;
+ default:
+ ret = -EOPNOTSUPP;
+ }
+
+ mutex_unlock(&data->dev_access_lock);
+
+ return ret;
+}
+
+static int cc2_write(struct device *dev, enum hwmon_sensor_types type, u32 attr,
+ int channel, long val)
+{
+ struct cc2_data *data = dev_get_drvdata(dev);
+ int ret;
+ u16 arg;
+ u8 cmd;
+
+ if (type != hwmon_humidity)
+ return -EOPNOTSUPP;
+
+ if (val < 0 || val > CC2_RH_MAX)
+ return -EINVAL;
+
+ mutex_lock(&data->dev_access_lock);
+
+ switch (attr) {
+ case hwmon_humidity_min:
+ cmd = CC2_W_ALARM_L_ON;
+ arg = cc2_rh_to_reg(val);
+ ret = cc2_write_reg(data, cmd, arg);
+ break;
+
+ case hwmon_humidity_min_hyst:
+ cmd = CC2_W_ALARM_L_OFF;
+ arg = cc2_rh_to_reg(val);
+ ret = cc2_write_reg(data, cmd, arg);
+ break;
+
+ case hwmon_humidity_max:
+ cmd = CC2_W_ALARM_H_ON;
+ arg = cc2_rh_to_reg(val);
+ ret = cc2_write_reg(data, cmd, arg);
+ break;
+
+ case hwmon_humidity_max_hyst:
+ cmd = CC2_W_ALARM_H_OFF;
+ arg = cc2_rh_to_reg(val);
+ ret = cc2_write_reg(data, cmd, arg);
+ break;
+
+ default:
+ ret = -EOPNOTSUPP;
+ break;
+ }
+
+ mutex_unlock(&data->dev_access_lock);
+
+ return ret;
+}
+
+static int cc2_request_ready_irq(struct cc2_data *data, struct device *dev)
+{
+ int ret = 0;
+
+ data->irq_ready = fwnode_irq_get_byname(dev_fwnode(dev), "ready");
+ if (data->irq_ready > 0) {
+ init_completion(&data->complete);
+ ret = devm_request_threaded_irq(dev, data->irq_ready, NULL,
+ cc2_ready_interrupt,
+ IRQF_ONESHOT |
+ IRQF_TRIGGER_RISING,
+ dev_name(dev), data);
+ }
+
+ return ret;
+}
+
+static int cc2_request_alarm_irqs(struct cc2_data *data, struct device *dev)
+{
+ int ret;
+
+ data->irq_low = fwnode_irq_get_byname(dev_fwnode(dev), "low");
+ if (data->irq_low > 0) {
+ ret = devm_request_threaded_irq(dev, data->irq_low, NULL,
+ cc2_low_interrupt,
+ IRQF_ONESHOT |
+ IRQF_TRIGGER_RISING,
+ dev_name(dev), data);
+ if (!ret)
+ data->rh_alarm.low_alarm_visible = true;
+ }
+
+ data->irq_high = fwnode_irq_get_byname(dev_fwnode(dev), "high");
+ if (data->irq_high > 0) {
+ ret = devm_request_threaded_irq(dev, data->irq_high, NULL,
+ cc2_high_interrupt,
+ IRQF_ONESHOT |
+ IRQF_TRIGGER_RISING,
+ dev_name(dev), data);
+ if (!ret)
+ data->rh_alarm.high_alarm_visible = true;
+ }
+
+ return ret;
+}
+
+static const struct hwmon_channel_info *cc2_info[] = {
+ HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT),
+ HWMON_CHANNEL_INFO(humidity, HWMON_H_INPUT | HWMON_H_MIN | HWMON_H_MAX |
+ HWMON_H_MIN_HYST | HWMON_H_MAX_HYST |
+ HWMON_H_MIN_ALARM | HWMON_H_MAX_ALARM),
+ NULL
+};
+
+static const struct hwmon_ops cc2_hwmon_ops = {
+ .is_visible = cc2_is_visible,
+ .read = cc2_read,
+ .write = cc2_write,
+};
+
+static const struct hwmon_chip_info cc2_chip_info = {
+ .ops = &cc2_hwmon_ops,
+ .info = cc2_info,
+};
+
+static int cc2_probe(struct i2c_client *client)
+{
+ struct cc2_data *data;
+ 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;
+
+ i2c_set_clientdata(client, data);
+
+ mutex_init(&data->dev_access_lock);
+
+ data->client = client;
+
+ data->regulator = devm_regulator_get_exclusive(dev, "vdd");
+ if (IS_ERR(data->regulator)) {
+ dev_err_probe(dev, PTR_ERR(data->regulator),
+ "Failed to get regulator\n");
+ return PTR_ERR(data->regulator);
+ }
+
+ ret = cc2_request_ready_irq(data, dev);
+ if (ret) {
+ dev_err_probe(dev, ret, "Failed to request ready irq\n");
+ return ret;
+ }
+
+ ret = cc2_request_alarm_irqs(data, dev);
+ if (ret) {
+ dev_err_probe(dev, ret, "Failed to request alarm irqs\n");
+ goto disable;
+ }
+
+ data->hwmon = devm_hwmon_device_register_with_info(dev, client->name,
+ data, &cc2_chip_info,
+ NULL);
+ if (IS_ERR(data->hwmon)) {
+ dev_err_probe(dev, PTR_ERR(data->hwmon),
+ "Failed to register hwmon device\n");
+ ret = PTR_ERR(data->hwmon);
+ }
+
+disable:
+ cc2_disable(data);
+
+ return ret;
+}
+
+static void cc2_remove(struct i2c_client *client)
+{
+ struct cc2_data *data = i2c_get_clientdata(client);
+
+ cc2_disable(data);
+}
+
+static const struct i2c_device_id cc2_id[] = {
+ { "cc2d23" },
+ { "cc2d23s" },
+ { "cc2d25" },
+ { "cc2d25s" },
+ { "cc2d33" },
+ { "cc2d33s" },
+ { "cc2d35" },
+ { "cc2d35s" },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, cc2_id);
+
+static const struct of_device_id cc2_of_match[] = {
+ { .compatible = "amphenol,cc2d23" },
+ { .compatible = "amphenol,cc2d23s" },
+ { .compatible = "amphenol,cc2d25" },
+ { .compatible = "amphenol,cc2d25s" },
+ { .compatible = "amphenol,cc2d33" },
+ { .compatible = "amphenol,cc2d33s" },
+ { .compatible = "amphenol,cc2d35" },
+ { .compatible = "amphenol,cc2d35s" },
+ { },
+};
+MODULE_DEVICE_TABLE(of, cc2_of_match);
+
+static struct i2c_driver cc2_driver = {
+ .driver = {
+ .name = "cc2d23",
+ .of_match_table = cc2_of_match,
+ },
+ .probe = cc2_probe,
+ .remove = cc2_remove,
+ .id_table = cc2_id,
+};
+module_i2c_driver(cc2_driver);
+
+MODULE_AUTHOR("Javier Carrasco <javier.carrasco.cruz@gamil.com>");
+MODULE_DESCRIPTION("Amphenol ChipCap 2 humidity and temperature sensor driver");
+MODULE_LICENSE("GPL");

--
2.39.2