* [PATCH v6 0/2] add support for MCP998X
@ 2025-09-30 13:31 victor.duicu
2025-09-30 13:31 ` [PATCH v6 1/2] dt-bindings: iio: temperature: " victor.duicu
` (2 more replies)
0 siblings, 3 replies; 7+ messages in thread
From: victor.duicu @ 2025-09-30 13:31 UTC (permalink / raw)
To: jic23, dlechner, nuno.sa, andy, robh, krzk+dt, conor+dt
Cc: marius.cristea, victor.duicu, linux-iio, linux-kernel, devicetree
From: Victor Duicu <victor.duicu@microchip.com>
Add support for Microchip MCP998X/33 and MCP998XD/33D Multichannel
Automotive Temperature Monitor Family.
The chips in the family have different numbers of external channels,
ranging from 1 (MCP9982) to 4 channels (MCP9985). Reading diodes in
anti-parallel connection is supported by MCP9984/85/33 and
MCP9984D/85D/33D. Dedicated hardware shutdown circuitry is present
only in MCP998XD and MCP9933D.
This driver was submitted in the IIO subsystem because the chips could use
interrupts to handle threshold events. Each chip supports 3 user
programmable limits per channel. The family is also capable of detecting
hottest diode and diode faults.
These features will be added in future patches.
Differences related to previous patch:
v6:
- in yaml first condition list part numbers instead
of regular expression. Add ^ to regular expression.
- edit coding style and comments.
- use hex values in defines.
- remove MCP9982_TEMP_MEM_BLOCK_LOW and
MCP9982_TEMP_MEM_BLOCK_HIGH.
- in MCP9982_CHAN() place macro parameters in ().
- move all variable definitions at the start of functions.
- in mcp9982_parse_fw_config() initialise iio_idx to 0.
- remove bit flags.
- in MCP9982_CHAN remove outer ().
- remove variable start in mcp9982_write_raw().
- replace constant in .max_register.
- use get_unaligned_be16 in mcp9982_read_raw().
v5:
- in yaml edit description of interrupts.
- add min and maxItems to reg.
- remove ideality parameter.
- use pattern recognition in conditionals.
- group conditions based on the chip.
- correct microchip,parasitic-res-on-channel3-4 to true.
- in driver include bitops.h.
- change name of some variables.
- rename mcp9982_parse_of_config() to mcp9982_parse_fw_config().
- implement bulk reading of temp registers.
- lock ideality parameter to default value.
- implement bit flags.
- add compound literal to MCP9982_CHAN.
- remove hysteresis parameter.
- edit comments.
- change values from int to bool in mcp9982_features.
- remove mcp9982_calc_all_3db_values() and hardcode values.
When filter is OFF the 3db value is equal to frequency.
- add .max_register to regmap_config.
- remove devm_kcalloc().
- in mcp9982_read_avail() add an else branch to hw_thermal_shutdown
check.
- in mcp9982_read_raw use USEC_PER_MSEC and set regmap_read_poll_timeout
to never timeout.
Replace switch with bitmap_weight.
- in mcp9982_read_label() remove unnecessary if.
- in mcp9982_write_raw() remove duplicated code.
- in mcp9982_init add error messages when APDD and RECD are incorrectly
set.
- in mcp9982_parse_fw_config() add default for reg_nr.
v4:
- lock beta parameters to default value of beta-autodetect.
Remove beta parameters and checks from devicetree.
- lock temperature range to extended.
This change avoids the issue of the average filter using raw values
with different scales when changing the range.
- change driver to wait an amount of time before reading a raw value
to ensure it is valid.
- change driver to stop calculating the physical temp when reading
in_tempx_raw. Reading from in_tempx_raw will return the raw value.
The physical temp will be calculated with in_tempx_raw, scale and
offset parameters.
- add scale parameter to channel definition.
- initialise chips with "D" to work in Run state and those without
in Standby state.
- when activating the low pass filter for chips without "D",
set the power state to RUN to ensure fresh values for the average.
- add minimum and maximum to microchip,beta1 and microchip,beta2 in yaml.
- rename microchip,resistance-comp-ch1-2-enable and
microchip,resistance-comp-ch3-4-enable to
microchip,parasitic-res-on-channel1-2
and microchip,parasitic-res-on-channel3-4
and edit description in yaml.
- add conditional logic to check if the chip supports APDD
and force default values where necessary in yaml.
- edit comments and coding style.
- replace asm/div64.h with linux/math64.h.
- add delay.h to includes.
- redefine mcp9982_sampl_fr with new structure division.
- in mcp9982_priv remove dev_name,extended_temp_range and beta_values.
Add run_state, wait_before_read, time_limit and pointer to chip
structure to remove all instances of matching strings.
Reorder parameters for memory optimization.
- in mcp9982_features add flags to know if the chip has thermal shutdown
circuitry and supports APDD.
- in mcp9982_read_avail() rework verification of chip type in sampling
frequency case.
- in mcp9982_read_raw() rework switch in low pass filter case.
- in mcp9982_parse_of_config() replace generic -EINVAL code
with -E2BIG and -EOVERFLOW.
v3:
- move beta parameters to devicetree.
- change the name of the interrupts and add
check to match them to the device in yaml.
- remove label for device and remove "0x" from
channel registers in example in yaml.
- edit comments in yaml and driver.
- add minItems to interrupts in yaml.
- rename microchip,recd12 and microchip,recd34 to
microchip,resistance-comp-ch1-2-enable
and microchip,resistance-comp-ch3-4-enable.
- rename microchip,apdd-state to microchip,enable-anti-parallel.
- add static to mcp9982_3db_values_map_tbl to fix
kernel test robot warning.
- in mcp9982_init() add check to ensure that hardware
shutdown feature can't be overridden.
- replace div_u64_rem with do_div and add
asm/div64.h to includes.
- remove unused includes.
- add iio_chan_spec in the macro definition of MCP9982_CHAN.
- remove MCP9982_EXT_BETA_ENBL.
- in mcp9982_init() replace regmap_assign_bits
with regmap_write when setting beta compensation.
- remove custom attribute enable_extended_temp_range and
map it to IIO_CHAN_INFO_OFFSET.
- add unsigned to int variables that allow it.
- reorder parameters in mcp9982_priv, change some
from int to bool, add const to labels and add dev_name.
- add check for chips with "D" in the name to not
allow sampling frequencies lower than 1 to
prevent overriding of hardware shutdown.
- remove mcp9982_attributes.
- move mcp9982_calc_all_3db_values() to before
mcp9982_init().
- use MICRO instead of number constant.
- in mcp9982_write_raw replace ">=" with "==".
- rename index2 to idx in mcp9982_read_raw().
- remove i2c_set_clientdata() in mcp9982_probe().
- since there are no more custom ABI attributes
the testing file was removed.
v2:
- move hysteresis, extended temperature range and beta parameters
from devicetree into user space.
- edit comments in yaml and driver.
- remove "|" in descpriptions, remove "+" from PatternProperties in yaml.
- add default to microchip,ideality-factor, delete blank lines and wrap to
80 chars in yaml.
- remove variables with upper case.
- add check for microchip,apdd-state and microchip,recd34 in yaml.
- improve coding style in driver code.
- add includes for all functions used.
- rename MCP9982_INT_HIGH_BYTE_ADDR to MCP9982_INT_VALUE_ADDR and
MCP9982_INT_LOW_BYTE_ADDR to MCP9982_FRAC_VALUE_ADDR.
- remove custom attribute running_average_window and
running_average_window_available and map them to a low pass filter.
- update sysfs-bus-iio-temperature-mcp9982 to reflect current
driver attributes and point to next kernel version (6.17).
- use compound literal to define driver channels.
- replace device_property_read_string() with i2c_get_match_data() to read
chip name from devicetree.
- remove MCP9982_DEV_ATTR and mcp9982_prep_custom_attributes().
- remove client, chip_name, iio_info from mcp9982_priv.
- replace sprintf() with sysfs_emit().
- remove error messages which are triggered by keyboard input.
- replace devm_kzalloc() with devm_kcalloc(), array mcp9982_chip_config[]
with individual structures, device_property_present() with
device_property_read_bool().
- reordered parameters in mcp9982_features and mcp9982_priv to optimize
memory allocation.
- remove .endianness from channel properties.
- change name of some parameters in mcp9982_priv.
- add check for reg value 0 from devicetree (channel 0 is for internal
temperature and can't be disabled).
v1:
- initial version.
Victor Duicu (2):
dt-bindings: iio: temperature: add support for MCP998X
iio: temperature: add support for MCP998X
.../iio/temperature/microchip,mcp9982.yaml | 190 ++++
MAINTAINERS | 7 +
drivers/iio/temperature/Kconfig | 10 +
drivers/iio/temperature/Makefile | 1 +
drivers/iio/temperature/mcp9982.c | 862 ++++++++++++++++++
5 files changed, 1070 insertions(+)
create mode 100644 Documentation/devicetree/bindings/iio/temperature/microchip,mcp9982.yaml
create mode 100644 drivers/iio/temperature/mcp9982.c
base-commit: 561285d048053fec8a3d6d1e3ddc60df11c393a0
--
2.48.1
^ permalink raw reply [flat|nested] 7+ messages in thread
* [PATCH v6 1/2] dt-bindings: iio: temperature: add support for MCP998X
2025-09-30 13:31 [PATCH v6 0/2] add support for MCP998X victor.duicu
@ 2025-09-30 13:31 ` victor.duicu
2025-09-30 13:31 ` [PATCH v6 2/2] " victor.duicu
2025-10-04 14:11 ` [PATCH v6 0/2] " Jonathan Cameron
2 siblings, 0 replies; 7+ messages in thread
From: victor.duicu @ 2025-09-30 13:31 UTC (permalink / raw)
To: jic23, dlechner, nuno.sa, andy, robh, krzk+dt, conor+dt
Cc: marius.cristea, victor.duicu, linux-iio, linux-kernel, devicetree
From: Victor Duicu <victor.duicu@microchip.com>
This is the devicetree schema for Microchip MCP998X/33 and MCP998XD/33D
Multichannel Automotive Temperature Monitor Family.
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Victor Duicu <victor.duicu@microchip.com>
---
.../iio/temperature/microchip,mcp9982.yaml | 190 ++++++++++++++++++
MAINTAINERS | 6 +
2 files changed, 196 insertions(+)
create mode 100644 Documentation/devicetree/bindings/iio/temperature/microchip,mcp9982.yaml
diff --git a/Documentation/devicetree/bindings/iio/temperature/microchip,mcp9982.yaml b/Documentation/devicetree/bindings/iio/temperature/microchip,mcp9982.yaml
new file mode 100644
index 000000000000..f0e0564c333f
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/temperature/microchip,mcp9982.yaml
@@ -0,0 +1,190 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/temperature/microchip,mcp9982.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Microchip MCP998X/33 and MCP998XD/33D Temperature Monitor
+
+maintainers:
+ - Victor Duicu <victor.duicu@microchip.com>
+
+description: |
+ The MCP998X/33 and MCP998XD/33D family is a high-accuracy 2-wire
+ multichannel automotive temperature monitor.
+ The datasheet can be found here:
+ https://ww1.microchip.com/downloads/aemDocuments/documents/MSLD/ProductDocuments/DataSheets/MCP998X-Family-Data-Sheet-DS20006827.pdf
+
+properties:
+ compatible:
+ enum:
+ - microchip,mcp9933
+ - microchip,mcp9933d
+ - microchip,mcp9982
+ - microchip,mcp9982d
+ - microchip,mcp9983
+ - microchip,mcp9983d
+ - microchip,mcp9984
+ - microchip,mcp9984d
+ - microchip,mcp9985
+ - microchip,mcp9985d
+
+ reg:
+ maxItems: 1
+
+ interrupts:
+ items:
+ - description: Signal coming from ALERT/THERM pin.
+ - description: Signal coming from THERM/ADDR pin.
+ - description: Signal coming from SYS_SHDN pin.
+
+ interrupt-names:
+ items:
+ - const: alert-therm
+ - const: therm-addr
+ - const: sys-shutdown
+
+ "#address-cells":
+ const: 1
+
+ "#size-cells":
+ const: 0
+
+ microchip,enable-anti-parallel:
+ description:
+ Enable anti-parallel diode mode operation.
+ MCP9984/84D/85/85D and MCP9933/33D support reading two external diodes
+ in anti-parallel connection on the same set of pins.
+ type: boolean
+
+ microchip,parasitic-res-on-channel1-2:
+ description:
+ Indicates that the chip and the diodes/transistors are sufficiently far
+ apart that a parasitic resistance is added to the wires, which can affect
+ the measurements. Due to the anti-parallel diode connections, channels
+ 1 and 2 are affected together.
+ type: boolean
+
+ microchip,parasitic-res-on-channel3-4:
+ description:
+ Indicates that the chip and the diodes/transistors are sufficiently far
+ apart that a parasitic resistance is added to the wires, which can affect
+ the measurements. Due to the anti-parallel diode connections, channels
+ 3 and 4 are affected together.
+ type: boolean
+
+ vdd-supply: true
+
+patternProperties:
+ "^channel@[1-4]$":
+ description:
+ Represents the external temperature channels to which
+ a remote diode is connected.
+ type: object
+
+ properties:
+ reg:
+ items:
+ minItems: 1
+ maxItems: 4
+
+ label:
+ description: Unique name to identify which channel this is.
+
+ required:
+ - reg
+
+ additionalProperties: false
+
+required:
+ - compatible
+ - reg
+ - vdd-supply
+
+allOf:
+ - if:
+ properties:
+ compatible:
+ contains:
+ enum:
+ - microchip,mcp9982d
+ - microchip,mcp9983d
+ - microchip,mcp9984d
+ - microchip,mcp9985d
+ - microchip,mcp9933d
+ then:
+ properties:
+ interrupts-names:
+ items:
+ - const: alert-therm
+ - const: sys-shutdown
+ else:
+ properties:
+ interrupts-names:
+ items:
+ - const: alert-therm
+ - const: therm-addr
+
+ - if:
+ properties:
+ compatible:
+ contains:
+ pattern: '^microchip,mcp998(2|3)$'
+ then:
+ properties:
+ microchip,enable-anti-parallel: false
+
+ - if:
+ properties:
+ compatible:
+ contains:
+ pattern: '^microchip,mcp998(2|3)d$'
+ then:
+ properties:
+ microchip,enable-anti-parallel: false
+ microchip,parasitic-res-on-channel1-2: true
+ microchip,parasitic-res-on-channel3-4: true
+
+ - if:
+ properties:
+ compatible:
+ contains:
+ pattern: '^microchip,mcp99(33|8[4-5])d$'
+ then:
+ properties:
+ microchip,parasitic-res-on-channel1-2: true
+ microchip,parasitic-res-on-channel3-4: true
+
+additionalProperties: false
+
+examples:
+ - |
+ i2c {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ temperature-sensor@4c {
+ compatible = "microchip,mcp9985";
+ reg = <0x4c>;
+
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ microchip,enable-anti-parallel;
+ microchip,parasitic-res-on-channel1-2;
+ microchip,parasitic-res-on-channel3-4;
+ vdd-supply = <&vdd>;
+
+ channel@1 {
+ reg = <1>;
+ label = "Interior Temperature";
+ };
+
+ channel@2 {
+ reg = <2>;
+ label = "GPU Temperature";
+ };
+ };
+ };
+
+...
diff --git a/MAINTAINERS b/MAINTAINERS
index f090c2f6e63a..a1981c2f659b 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -16662,6 +16662,12 @@ S: Maintained
F: Documentation/devicetree/bindings/iio/adc/microchip,mcp3911.yaml
F: drivers/iio/adc/mcp3911.c
+MICROCHIP MCP9982 TEMPERATURE DRIVER
+M: Victor Duicu <victor.duicu@microchip.com>
+L: linux-iio@vger.kernel.org
+S: Supported
+F: Documentation/devicetree/bindings/iio/temperature/microchip,mcp9982.yaml
+
MICROCHIP MMC/SD/SDIO MCI DRIVER
M: Aubin Constans <aubin.constans@microchip.com>
S: Maintained
--
2.48.1
^ permalink raw reply related [flat|nested] 7+ messages in thread
* [PATCH v6 2/2] iio: temperature: add support for MCP998X
2025-09-30 13:31 [PATCH v6 0/2] add support for MCP998X victor.duicu
2025-09-30 13:31 ` [PATCH v6 1/2] dt-bindings: iio: temperature: " victor.duicu
@ 2025-09-30 13:31 ` victor.duicu
2025-10-02 0:13 ` kernel test robot
2025-10-04 14:17 ` Jonathan Cameron
2025-10-04 14:11 ` [PATCH v6 0/2] " Jonathan Cameron
2 siblings, 2 replies; 7+ messages in thread
From: victor.duicu @ 2025-09-30 13:31 UTC (permalink / raw)
To: jic23, dlechner, nuno.sa, andy, robh, krzk+dt, conor+dt
Cc: marius.cristea, victor.duicu, linux-iio, linux-kernel, devicetree
From: Victor Duicu <victor.duicu@microchip.com>
This is the driver for Microchip MCP998X/33 and MCP998XD/33D Multichannel
Automotive Temperature Monitor Family.
Signed-off-by: Victor Duicu <victor.duicu@microchip.com>
---
MAINTAINERS | 1 +
drivers/iio/temperature/Kconfig | 10 +
drivers/iio/temperature/Makefile | 1 +
drivers/iio/temperature/mcp9982.c | 862 ++++++++++++++++++++++++++++++
4 files changed, 874 insertions(+)
create mode 100644 drivers/iio/temperature/mcp9982.c
diff --git a/MAINTAINERS b/MAINTAINERS
index a1981c2f659b..1fb2aad63800 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -16667,6 +16667,7 @@ M: Victor Duicu <victor.duicu@microchip.com>
L: linux-iio@vger.kernel.org
S: Supported
F: Documentation/devicetree/bindings/iio/temperature/microchip,mcp9982.yaml
+F: drivers/iio/temperature/mcp9982.c
MICROCHIP MMC/SD/SDIO MCI DRIVER
M: Aubin Constans <aubin.constans@microchip.com>
diff --git a/drivers/iio/temperature/Kconfig b/drivers/iio/temperature/Kconfig
index 9328b2250ace..d1751db6bf6f 100644
--- a/drivers/iio/temperature/Kconfig
+++ b/drivers/iio/temperature/Kconfig
@@ -184,4 +184,14 @@ config MCP9600
This driver can also be built as a module. If so, the module
will be called mcp9600.
+config MCP9982
+ tristate "Microchip Technology MCP9982 driver"
+ depends on I2C
+ help
+ Say yes here to build support for Microchip Technology's MCP998X/33
+ and MCP998XD/33D Multichannel Automotive Temperature Monitor Family.
+
+ This driver can also be built as a module. If so, the module
+ will be called mcp9982.
+
endmenu
diff --git a/drivers/iio/temperature/Makefile b/drivers/iio/temperature/Makefile
index 07d6e65709f7..83f5f4bb4ff3 100644
--- a/drivers/iio/temperature/Makefile
+++ b/drivers/iio/temperature/Makefile
@@ -11,6 +11,7 @@ obj-$(CONFIG_MAX30208) += max30208.o
obj-$(CONFIG_MAX31856) += max31856.o
obj-$(CONFIG_MAX31865) += max31865.o
obj-$(CONFIG_MCP9600) += mcp9600.o
+obj-$(CONFIG_MCP9982) += mcp9982.o
obj-$(CONFIG_MLX90614) += mlx90614.o
obj-$(CONFIG_MLX90632) += mlx90632.o
obj-$(CONFIG_MLX90632) += mlx90635.o
diff --git a/drivers/iio/temperature/mcp9982.c b/drivers/iio/temperature/mcp9982.c
new file mode 100644
index 000000000000..2d01ea8ae1dc
--- /dev/null
+++ b/drivers/iio/temperature/mcp9982.c
@@ -0,0 +1,862 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * IIO driver for MCP998X/33 and MCP998XD/33D Multichannel Automotive Temperature Monitor Family
+ *
+ * Copyright (C) 2025 Microchip Technology Inc. and its subsidiaries
+ *
+ * Author: Victor Duicu <victor.duicu@microchip.com>
+ *
+ * Datasheet can be found here:
+ * https://ww1.microchip.com/downloads/aemDocuments/documents/MSLD/ProductDocuments/DataSheets/MCP998X-Family-Data-Sheet-DS20006827.pdf
+ */
+
+#include <linux/array_size.h>
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/delay.h>
+#include <linux/device/devres.h>
+#include <linux/dev_printk.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/iio/iio.h>
+#include <linux/math64.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+#include <linux/string.h>
+#include <linux/units.h>
+
+/* MCP9982 Registers */
+#define MCP9982_HIGH_BYTE_ADDR(index) (2 * (index))
+#define MCP9982_ONE_SHOT_ADDR 0x0A
+#define MCP9982_INTERNAL_HIGH_LIMIT_ADDR 0x0B
+#define MCP9982_INTERNAL_LOW_LIMIT_ADDR 0x0C
+#define MCP9982_EXT1_HIGH_LIMIT_HIGH_BYTE_ADDR 0x0D
+#define MCP9982_EXT1_HIGH_LIMIT_LOW_BYTE_ADDR 0x0E
+#define MCP9982_EXT1_LOW_LIMIT_HIGH_BYTE_ADDR 0x0F
+#define MCP9982_EXT1_LOW_LIMIT_LOW_BYTE_ADDR 0x10
+#define MCP9982_INTERNAL_THERM_LIMIT_ADDR 0x1D
+#define MCP9982_EXT1_THERM_LIMIT_ADDR 0x1E
+#define MCP9982_CFG_ADDR 0x22
+#define MCP9982_CONV_ADDR 0x24
+#define MCP9982_HYS_ADDR 0x25
+#define MCP9982_CONSEC_ALRT_ADDR 0x26
+#define MCP9982_ALRT_CFG_ADDR 0x27
+#define MCP9982_RUNNING_AVG_ADDR 0x28
+#define MCP9982_HOTTEST_CFG_ADDR 0x29
+#define MCP9982_STATUS_ADDR 0x2A
+#define MCP9982_EXT_FAULT_STATUS_ADDR 0x2B
+#define MCP9982_HIGH_LIMIT_STATUS_ADDR 0x2C
+#define MCP9982_LOW_LIMIT_STATUS_ADDR 0x2D
+#define MCP9982_THERM_LIMIT_STATUS_ADDR 0x2E
+#define MCP9982_HOTTEST_HIGH_BYTE_ADDR 0x2F
+#define MCP9982_HOTTEST_LOW_BYTE_ADDR 0x30
+#define MCP9982_HOTTEST_STATUS_ADDR 0x31
+#define MCP9982_THERM_SHTDWN_CFG_ADDR 0x32
+#define MCP9982_HRDW_THERM_SHTDWN_LIMIT_ADDR 0x33
+
+/* 34 is the start address for the beta registers. */
+#define MCP9982_EXT_BETA_CFG_ADDR(index) ((index) + 0x34)
+/* 36 is the start address for ideality registers. */
+#define MCP9982_EXT_IDEAL_ADDR(index) ((index) + 0x36)
+/* 80 is the start address in decimal for temperature memory block */
+#define MCP9982_TEMP_MEM_BLOCK_ADDR(index) (2 * (index) + 0x80)
+
+/* MCP9982 Bits */
+#define MCP9982_CFG_MSKAL BIT(7)
+#define MCP9982_CFG_RS BIT(6)
+#define MCP9982_CFG_ATTHM BIT(5)
+#define MCP9982_CFG_RECD12 BIT(4)
+#define MCP9982_CFG_RECD34 BIT(3)
+#define MCP9982_CFG_RANGE BIT(2)
+#define MCP9982_CFG_DA_ENA BIT(1)
+#define MCP9982_CFG_APDD BIT(0)
+#define MCP9982_STATUS_BUSY BIT(5)
+
+/* The maximum number of channels a member of the family can have. */
+#define MCP9982_MAX_NUM_CHANNELS 5
+#define MCP9982_BETA_AUTODETECT 16
+#define MCP9982_IDEALITY_DEFAULT 18
+#define MCP9982_OFFSET -64
+#define MCP9982_SCALE 3906250
+
+#define MCP9982_CHAN(index, si, __address) \
+ (struct iio_chan_spec) { \
+ .type = IIO_TEMP, \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+ .info_mask_shared_by_all_available = BIT(IIO_CHAN_INFO_SAMP_FREQ) | \
+ BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY), \
+ .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ) | \
+ BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY) | \
+ BIT(IIO_CHAN_INFO_OFFSET) | \
+ BIT(IIO_CHAN_INFO_SCALE), \
+ .channel = (index), \
+ .address = (__address), \
+ .scan_index = (si), \
+ .scan_type = { \
+ .sign = 'u', \
+ .realbits = 8, \
+ .storagebits = 8, \
+ }, \
+ .indexed = 1, \
+ } \
+
+/**
+ * struct mcp9982_features - features of a mcp9982 instance
+ * @name: chip's name
+ * @phys_channels: number of physical channels supported by the chip
+ * @hw_thermal_shutdown: presence of hardware thermal shutdown circuitry
+ * @allow_apdd: whether the chip supports enabling APDD
+ */
+struct mcp9982_features {
+ const char *name;
+ u8 phys_channels;
+ bool hw_thermal_shutdown;
+ bool allow_apdd;
+};
+
+static const struct mcp9982_features mcp9933_chip_config = {
+ .name = "mcp9933",
+ .phys_channels = 3,
+ .hw_thermal_shutdown = false,
+ .allow_apdd = true,
+};
+
+static const struct mcp9982_features mcp9933d_chip_config = {
+ .name = "mcp9933d",
+ .phys_channels = 3,
+ .hw_thermal_shutdown = true,
+ .allow_apdd = true,
+};
+
+static const struct mcp9982_features mcp9982_chip_config = {
+ .name = "mcp9982",
+ .phys_channels = 2,
+ .hw_thermal_shutdown = false,
+ .allow_apdd = false,
+};
+
+static const struct mcp9982_features mcp9982d_chip_config = {
+ .name = "mcp9982d",
+ .phys_channels = 2,
+ .hw_thermal_shutdown = true,
+ .allow_apdd = false,
+};
+
+static const struct mcp9982_features mcp9983_chip_config = {
+ .name = "mcp9983",
+ .phys_channels = 3,
+ .hw_thermal_shutdown = false,
+ .allow_apdd = false,
+};
+
+static const struct mcp9982_features mcp9983d_chip_config = {
+ .name = "mcp9983d",
+ .phys_channels = 3,
+ .hw_thermal_shutdown = true,
+ .allow_apdd = false,
+};
+
+static const struct mcp9982_features mcp9984_chip_config = {
+ .name = "mcp9984",
+ .phys_channels = 4,
+ .hw_thermal_shutdown = false,
+ .allow_apdd = true,
+};
+
+static const struct mcp9982_features mcp9984d_chip_config = {
+ .name = "mcp9984d",
+ .phys_channels = 4,
+ .hw_thermal_shutdown = true,
+ .allow_apdd = true,
+};
+
+static const struct mcp9982_features mcp9985_chip_config = {
+ .name = "mcp9985",
+ .phys_channels = 5,
+ .hw_thermal_shutdown = false,
+ .allow_apdd = true,
+};
+
+static const struct mcp9982_features mcp9985d_chip_config = {
+ .name = "mcp9985d",
+ .phys_channels = 5,
+ .hw_thermal_shutdown = true,
+ .allow_apdd = true,
+};
+
+static const unsigned int mcp9982_conv_rate[][2] = {
+ { 0, 62500 },
+ { 0, 125000 },
+ { 0, 250000 },
+ { 0, 500000 },
+ { 1, 0 },
+ { 2, 0 },
+ { 4, 0 },
+ { 8, 0 },
+ { 16, 0 },
+ { 32, 0 },
+ { 64, 0 },
+};
+
+/*
+ * Constants were calculated using:
+ * (Sampling_Frequency(Hz) * 1000000) / (Window_Size * 2)
+ * The formula is used for Window_Size = { 4, 8 }.
+ * For Window_Size = 1 the filter is OFF and the 3db value
+ * is equal to the frequency.
+ */
+static const unsigned int mcp9982_3db_values_map_tbl[11][3][2] = {
+ {
+ { 0, 62500 },
+ { 0, 7812 },
+ { 0, 3906 },
+ },
+ {
+ { 0, 125000 },
+ { 0, 15625 },
+ { 0, 7812 },
+ },
+ {
+ { 0, 250000 },
+ { 0, 31250 },
+ { 0, 15625 },
+ },
+ {
+ { 0, 500000 },
+ { 0, 62500 },
+ { 0, 31250 },
+ },
+ {
+ { 1, 0 },
+ { 0, 125000 },
+ { 0, 62500 },
+ },
+ {
+ { 2, 0 },
+ { 0, 250000 },
+ { 0, 125000 },
+ },
+ {
+ { 4, 0 },
+ { 0, 500000 },
+ { 0, 250000 },
+ },
+ {
+ { 8, 0 },
+ { 1, 0 },
+ { 0, 500000 },
+ },
+ {
+ { 16, 0 },
+ { 2, 0 },
+ { 1, 0 },
+ },
+ {
+ { 32, 0 },
+ { 4, 0 },
+ { 2, 0 },
+ },
+ {
+ { 64, 0 },
+ { 8, 0 },
+ { 4, 0 },
+ },
+};
+
+/* The delay, in milliseconds, needed to allow the conversion to end. */
+static const u64 mcp9982_delay_ms[11] = {
+ 16125,
+ 8125,
+ 4125,
+ 2125,
+ 1125,
+ 625,
+ 375,
+ 255,
+ 190,
+ 160,
+ 145,
+};
+
+/* MCP9982 regmap configuration */
+static const struct regmap_range mcp9982_regmap_wr_ranges[] = {
+ regmap_reg_range(MCP9982_ONE_SHOT_ADDR,
+ MCP9982_EXT1_LOW_LIMIT_LOW_BYTE_ADDR),
+ regmap_reg_range(MCP9982_INTERNAL_THERM_LIMIT_ADDR,
+ MCP9982_EXT1_THERM_LIMIT_ADDR),
+ regmap_reg_range(MCP9982_CFG_ADDR, MCP9982_CFG_ADDR),
+ regmap_reg_range(MCP9982_CONV_ADDR, MCP9982_HOTTEST_CFG_ADDR),
+ regmap_reg_range(MCP9982_THERM_SHTDWN_CFG_ADDR,
+ MCP9982_THERM_SHTDWN_CFG_ADDR),
+ regmap_reg_range(MCP9982_EXT_BETA_CFG_ADDR(0),
+ MCP9982_EXT_IDEAL_ADDR(3)),
+ regmap_reg_range(MCP9982_TEMP_MEM_BLOCK_ADDR(0),
+ MCP9982_TEMP_MEM_BLOCK_ADDR(4) + 1),
+};
+
+static const struct regmap_access_table mcp9982_regmap_wr_table = {
+ .yes_ranges = mcp9982_regmap_wr_ranges,
+ .n_yes_ranges = ARRAY_SIZE(mcp9982_regmap_wr_ranges),
+};
+
+static const struct regmap_range mcp9982_regmap_rd_ranges[] = {
+ regmap_reg_range(MCP9982_HIGH_BYTE_ADDR(0),
+ MCP9982_EXT1_LOW_LIMIT_LOW_BYTE_ADDR),
+ regmap_reg_range(MCP9982_INTERNAL_THERM_LIMIT_ADDR,
+ MCP9982_EXT1_THERM_LIMIT_ADDR),
+ regmap_reg_range(MCP9982_CFG_ADDR, MCP9982_CFG_ADDR),
+ regmap_reg_range(MCP9982_CONV_ADDR, MCP9982_EXT_IDEAL_ADDR(3)),
+ regmap_reg_range(MCP9982_TEMP_MEM_BLOCK_ADDR(0),
+ MCP9982_TEMP_MEM_BLOCK_ADDR(4) + 1),
+};
+
+static const struct regmap_access_table mcp9982_regmap_rd_table = {
+ .yes_ranges = mcp9982_regmap_rd_ranges,
+ .n_yes_ranges = ARRAY_SIZE(mcp9982_regmap_rd_ranges),
+};
+
+static bool mcp9982_is_volatile_reg(struct device *dev, unsigned int reg)
+{
+ switch (reg) {
+ case MCP9982_ONE_SHOT_ADDR:
+ case MCP9982_INTERNAL_HIGH_LIMIT_ADDR:
+ case MCP9982_INTERNAL_LOW_LIMIT_ADDR:
+ case MCP9982_EXT1_HIGH_LIMIT_HIGH_BYTE_ADDR:
+ case MCP9982_EXT1_HIGH_LIMIT_LOW_BYTE_ADDR:
+ case MCP9982_EXT1_LOW_LIMIT_HIGH_BYTE_ADDR:
+ case MCP9982_EXT1_LOW_LIMIT_LOW_BYTE_ADDR:
+ case MCP9982_INTERNAL_THERM_LIMIT_ADDR:
+ case MCP9982_EXT1_THERM_LIMIT_ADDR:
+ case MCP9982_CFG_ADDR:
+ case MCP9982_CONV_ADDR:
+ case MCP9982_HYS_ADDR:
+ case MCP9982_CONSEC_ALRT_ADDR:
+ case MCP9982_ALRT_CFG_ADDR:
+ case MCP9982_RUNNING_AVG_ADDR:
+ case MCP9982_HOTTEST_CFG_ADDR:
+ case MCP9982_THERM_SHTDWN_CFG_ADDR:
+ return false;
+ default:
+ return true;
+ }
+}
+
+static const struct regmap_config mcp9982_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+ .rd_table = &mcp9982_regmap_rd_table,
+ .wr_table = &mcp9982_regmap_wr_table,
+ .volatile_reg = mcp9982_is_volatile_reg,
+ .max_register = MCP9982_TEMP_MEM_BLOCK_ADDR(4) + 1,
+};
+
+/**
+ * struct mcp9992_priv - information about chip parameters
+ * @regmap: device register map
+ * @chip: pointer to structure holding chip features
+ * @lock: synchronize access to driver's state members
+ * @iio_chan: specifications of channels
+ * @labels: labels of the channels
+ * @sampl_idx: index representing the current sampling frequency
+ * @time_limit: time when it is safe to read
+ * @num_channels: number of active physical channels
+ * @recd34_enable: state of Resistance Error Correction(REC) on channels 3 and 4
+ * @recd12_enable: state of Resistance Error Correction(REC) on channels 1 and 2
+ * @apdd_enable: state of anti-parallel diode mode
+ * @run_state: chip is in run state, otherwise is in standby state
+ * @wait_before_read: whether we need to wait a delay before reading a new value
+ */
+struct mcp9982_priv {
+ struct regmap *regmap;
+ const struct mcp9982_features *chip;
+ /* Synchronize access to driver's state members. */
+ struct mutex lock;
+ struct iio_chan_spec iio_chan[5];
+ const char *labels[MCP9982_MAX_NUM_CHANNELS];
+ unsigned int sampl_idx;
+ unsigned long time_limit;
+ u8 num_channels;
+ bool recd34_enable;
+ bool recd12_enable;
+ bool apdd_enable;
+ bool run_state;
+ bool wait_before_read;
+};
+
+static int mcp9982_read_avail(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, const int **vals,
+ int *type, int *length, long mask)
+{
+ struct mcp9982_priv *priv = iio_priv(indio_dev);
+ unsigned int idx;
+ unsigned int sub;
+
+ if (priv->chip->hw_thermal_shutdown) {
+ idx = 4;
+ sub = 8;
+ } else {
+ idx = 0;
+ sub = 0;
+ }
+ switch (mask) {
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ *type = IIO_VAL_INT_PLUS_MICRO;
+ *vals = mcp9982_conv_rate[idx];
+ *length = ARRAY_SIZE(mcp9982_conv_rate) * 2 - sub;
+ return IIO_AVAIL_LIST;
+ case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
+ *type = IIO_VAL_INT_PLUS_MICRO;
+ *vals = mcp9982_3db_values_map_tbl[priv->sampl_idx][0];
+ *length = ARRAY_SIZE(mcp9982_3db_values_map_tbl[priv->sampl_idx]) * 2;
+ return IIO_AVAIL_LIST;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int mcp9982_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int *val,
+ int *val2, long mask)
+{
+ unsigned int tmp_reg, reg_status;
+ struct mcp9982_priv *priv = iio_priv(indio_dev);
+ unsigned long *src;
+ int ret;
+ u8 bulk_read[3];
+
+ if (priv->run_state) {
+ /*
+ * When working in Run mode, after modifying a parameter (like sampling
+ * frequency) we have to wait a delay before reading the new values.
+ * We can't determine when the conversion is done based on the BUSY bit.
+ */
+ if (priv->wait_before_read) {
+ if (!time_after(jiffies, priv->time_limit))
+ mdelay(jiffies_to_msecs(priv->time_limit - jiffies));
+ priv->wait_before_read = false;
+ }
+ } else {
+ ret = regmap_write(priv->regmap, MCP9982_ONE_SHOT_ADDR, 1);
+ if (ret)
+ return ret;
+ /*
+ * In Standby state after writing in OneShot register wait for
+ * the start of conversion and then poll the BUSY bit.
+ */
+ mdelay(125);
+ ret = regmap_read_poll_timeout(priv->regmap, MCP9982_STATUS_ADDR,
+ reg_status, !(reg_status & MCP9982_STATUS_BUSY),
+ mcp9982_delay_ms[priv->sampl_idx] * USEC_PER_MSEC,
+ 0);
+ if (ret)
+ return ret;
+ }
+ guard(mutex)(&priv->lock);
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ /*
+ * The Block Read Protocol first returns the number of user readable
+ * bytes, held in bulk_read[0], followed by the data.
+ */
+ ret = regmap_bulk_read(priv->regmap, MCP9982_TEMP_MEM_BLOCK_ADDR(chan->channel),
+ &bulk_read, sizeof(bulk_read));
+ if (ret)
+ return ret;
+
+ *val = get_unaligned_be16(bulk_read + 1);
+
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_SCALE:
+ *val = 0;
+ *val2 = MCP9982_SCALE;
+ return IIO_VAL_INT_PLUS_NANO;
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ *val = mcp9982_conv_rate[priv->sampl_idx][0];
+ *val2 = mcp9982_conv_rate[priv->sampl_idx][1];
+ return IIO_VAL_INT_PLUS_MICRO;
+ case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
+ ret = regmap_read(priv->regmap, MCP9982_RUNNING_AVG_ADDR, &tmp_reg);
+ if (ret)
+ return ret;
+ *src = tmp_reg;
+ *val = mcp9982_3db_values_map_tbl[priv->sampl_idx][bitmap_weight(src, 2)][0];
+ *val2 = mcp9982_3db_values_map_tbl[priv->sampl_idx][bitmap_weight(src, 2)][1];
+ return IIO_VAL_INT_PLUS_MICRO;
+ case IIO_CHAN_INFO_OFFSET:
+ *val = MCP9982_OFFSET;
+ return IIO_VAL_INT;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int mcp9982_read_label(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, char *label)
+{
+ struct mcp9982_priv *priv = iio_priv(indio_dev);
+
+ return sysfs_emit(label, "%s\n", priv->labels[chan->channel]);
+}
+
+static int mcp9982_write_raw_get_fmt(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, long info)
+{
+ switch (info) {
+ case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ return IIO_VAL_INT_PLUS_MICRO;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int mcp9982_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int val,
+ int val2, long mask)
+{
+ unsigned int i, previous_sampl_idx;
+ struct mcp9982_priv *priv = iio_priv(indio_dev);
+ unsigned long new_time_limit;
+ bool use_previous_freq = false;
+ int ret;
+
+ i = 0;
+ guard(mutex)(&priv->lock);
+ switch (mask) {
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ previous_sampl_idx = priv->sampl_idx;
+
+ /* For MCP998XD and MCP9933D sampling frequency can't be lower than 1. */
+ if (priv->chip->hw_thermal_shutdown)
+ i = 4;
+ for (; i < ARRAY_SIZE(mcp9982_conv_rate); i++)
+ if (val == mcp9982_conv_rate[i][0] &&
+ val2 == mcp9982_conv_rate[i][1])
+ break;
+
+ if (i == ARRAY_SIZE(mcp9982_conv_rate))
+ return -EINVAL;
+
+ ret = regmap_write(priv->regmap, MCP9982_CONV_ADDR, i);
+ if (ret)
+ return ret;
+
+ priv->sampl_idx = i;
+
+ /*
+ * When changing the frequency in Run mode, wait a delay based
+ * on the previous value to ensure the new value becomes active.
+ */
+ if (priv->run_state)
+ use_previous_freq = true;
+
+ break;
+ case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
+ for (i = 0; i < ARRAY_SIZE(mcp9982_3db_values_map_tbl[priv->sampl_idx]); i++)
+ if (val == mcp9982_3db_values_map_tbl[priv->sampl_idx][i][0] &&
+ val2 == mcp9982_3db_values_map_tbl[priv->sampl_idx][i][1])
+ break;
+
+ if (i == ARRAY_SIZE(mcp9982_3db_values_map_tbl[priv->sampl_idx]))
+ return -EINVAL;
+
+ /*
+ * In mcp9982_3db_values_map_tbl the second index maps:
+ * 0 for filter off
+ * 1 for filter at level 1
+ * 2 for filter at level 2
+ */
+ if (i == 2)
+ i = 3;
+ /*
+ * If the digital filter is activated for chips without "D", set
+ * the power state to Run to ensure the averaging is made on fresh values.
+ */
+ if (!priv->chip->hw_thermal_shutdown) {
+ if (i == 0) {
+ ret = regmap_assign_bits(priv->regmap,
+ MCP9982_CFG_ADDR,
+ MCP9982_CFG_RS, 1);
+ priv->run_state = false;
+ } else {
+ ret = regmap_assign_bits(priv->regmap,
+ MCP9982_CFG_ADDR,
+ MCP9982_CFG_RS, 0);
+ priv->run_state = true;
+ }
+ }
+
+ ret = regmap_write(priv->regmap, MCP9982_RUNNING_AVG_ADDR, i);
+ if (ret)
+ return ret;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ if (priv->run_state) {
+ if (use_previous_freq) {
+ new_time_limit = jiffies +
+ msecs_to_jiffies(mcp9982_delay_ms[previous_sampl_idx]);
+ use_previous_freq = false;
+ } else {
+ new_time_limit = jiffies +
+ msecs_to_jiffies(mcp9982_delay_ms[priv->sampl_idx]);
+ }
+ if (time_after(new_time_limit, priv->time_limit)) {
+ priv->time_limit = new_time_limit;
+ priv->wait_before_read = true;
+ }
+ }
+
+ return 0;
+}
+
+static const struct iio_info mcp9982_info = {
+ .read_raw = mcp9982_read_raw,
+ .read_label = mcp9982_read_label,
+ .read_avail = mcp9982_read_avail,
+ .write_raw_get_fmt = mcp9982_write_raw_get_fmt,
+ .write_raw = mcp9982_write_raw,
+};
+
+static int mcp9982_init(struct device *dev, struct mcp9982_priv *priv)
+{
+ int ret;
+ unsigned int i;
+ u8 val;
+
+ /* Chips 82/83 and 82D/83D do not support anti-parallel diode mode. */
+ if (!priv->chip->allow_apdd && priv->apdd_enable == 1)
+ return dev_err_probe(dev, -EINVAL, "Incorrect setting of APDD.\n");
+
+ /* Chips with "D" work in Run state and those without work in Standby state. */
+ if (priv->chip->hw_thermal_shutdown)
+ priv->run_state = true;
+
+ /*
+ * For chips with "D" in the name, resistance error correction must be on
+ * so that hardware shutdown feature can't be overridden.
+ */
+ if (priv->chip->hw_thermal_shutdown)
+ if (!priv->recd34_enable || !priv->recd12_enable)
+ return dev_err_probe(dev, -EINVAL, "Incorrect setting of RECD.\n");
+ /*
+ * Set default values in registers.
+ *
+ * APDD, RECD12 and RECD34 are active on 0.
+ */
+ val = FIELD_PREP(MCP9982_CFG_MSKAL, 1) |
+ FIELD_PREP(MCP9982_CFG_RS, !priv->run_state) |
+ FIELD_PREP(MCP9982_CFG_ATTHM, 1) |
+ FIELD_PREP(MCP9982_CFG_RECD12, !priv->recd12_enable) |
+ FIELD_PREP(MCP9982_CFG_RECD34, !priv->recd34_enable) |
+ FIELD_PREP(MCP9982_CFG_RANGE, 1) | FIELD_PREP(MCP9982_CFG_DA_ENA, 0) |
+ FIELD_PREP(MCP9982_CFG_APDD, !priv->apdd_enable);
+
+ ret = regmap_write(priv->regmap, MCP9982_CFG_ADDR, val);
+ if (ret)
+ return ret;
+
+ ret = regmap_write(priv->regmap, MCP9982_CONV_ADDR, 6);
+ if (ret)
+ return ret;
+ priv->sampl_idx = 6;
+
+ ret = regmap_write(priv->regmap, MCP9982_HYS_ADDR, 10);
+ if (ret)
+ return ret;
+
+ ret = regmap_write(priv->regmap, MCP9982_CONSEC_ALRT_ADDR, 112);
+ if (ret)
+ return ret;
+
+ ret = regmap_write(priv->regmap, MCP9982_RUNNING_AVG_ADDR, 0);
+ if (ret)
+ return ret;
+
+ ret = regmap_write(priv->regmap, MCP9982_HOTTEST_CFG_ADDR, 0);
+ if (ret)
+ return ret;
+
+ /*
+ * Only external channels 1 and 2 support beta compensation.
+ * Set beta auto-detection.
+ */
+ for (i = 0; i < 2; i++) {
+ ret = regmap_write(priv->regmap, MCP9982_EXT_BETA_CFG_ADDR(i),
+ MCP9982_BETA_AUTODETECT);
+ if (ret)
+ return ret;
+ }
+ /* Set ideality factor to default for all external channels. */
+ for (i = 0; i < 4; i++) {
+ ret = regmap_write(priv->regmap, MCP9982_EXT_IDEAL_ADDR(i),
+ MCP9982_IDEALITY_DEFAULT);
+ if (ret)
+ return ret;
+ }
+
+ priv->wait_before_read = false;
+ priv->time_limit = jiffies;
+
+ return 0;
+}
+
+static int mcp9982_parse_fw_config(struct iio_dev *indio_dev, struct device *dev,
+ int device_nr_channels)
+{
+ unsigned int reg_nr;
+ unsigned int iio_idx = 0;
+ struct mcp9982_priv *priv = iio_priv(indio_dev);
+
+ priv->apdd_enable =
+ device_property_read_bool(dev, "microchip,enable-anti-parallel");
+
+ priv->recd12_enable =
+ device_property_read_bool(dev, "microchip,parasitic-res-on-channel1-2");
+
+ priv->recd34_enable =
+ device_property_read_bool(dev, "microchip,parasitic-res-on-channel3-4");
+
+ priv->num_channels = device_get_child_node_count(dev) + 1;
+
+ if (priv->num_channels > device_nr_channels)
+ return dev_err_probe(dev, -E2BIG,
+ "More channels than the chip supports\n");
+
+ /* Initialise internal channel( which is always present ). */
+ priv->iio_chan[0] = MCP9982_CHAN(0, 0, MCP9982_HIGH_BYTE_ADDR(0));
+ priv->labels[0] = "internal diode";
+
+ iio_idx++;
+ device_for_each_child_node_scoped(dev, child) {
+ reg_nr = 0;
+ fwnode_property_read_u32(child, "reg", ®_nr);
+ if (!reg_nr || reg_nr >= device_nr_channels)
+ return dev_err_probe(dev, -EINVAL,
+ "The index of the channels does not match the chip\n");
+
+ fwnode_property_read_string(child, "label",
+ &priv->labels[reg_nr]);
+
+ priv->iio_chan[iio_idx++] =
+ MCP9982_CHAN(reg_nr, reg_nr, MCP9982_HIGH_BYTE_ADDR(reg_nr));
+ }
+
+ return 0;
+}
+
+static int mcp9982_probe(struct i2c_client *client)
+{
+ struct device *dev = &client->dev;
+ struct mcp9982_priv *priv;
+ struct iio_dev *indio_dev;
+ const struct mcp9982_features *chip;
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(dev, sizeof(*priv));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ priv = iio_priv(indio_dev);
+ priv->regmap = devm_regmap_init_i2c(client, &mcp9982_regmap_config);
+ if (IS_ERR(priv->regmap))
+ return dev_err_probe(dev, PTR_ERR(priv->regmap),
+ "Cannot initialize register map\n");
+
+ ret = devm_mutex_init(dev, &priv->lock);
+ if (ret)
+ return ret;
+
+ chip = i2c_get_match_data(client);
+ if (!chip)
+ return -EINVAL;
+ priv->chip = chip;
+
+ ret = mcp9982_parse_fw_config(indio_dev, dev, chip->phys_channels);
+ if (ret)
+ return ret;
+
+ ret = mcp9982_init(dev, priv);
+ if (ret)
+ return ret;
+
+ indio_dev->name = chip->name;
+ indio_dev->info = &mcp9982_info;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->channels = priv->iio_chan;
+ indio_dev->num_channels = priv->num_channels;
+
+ ret = devm_iio_device_register(dev, indio_dev);
+ if (ret)
+ return dev_err_probe(dev, ret, "Cannot register IIO device\n");
+
+ return 0;
+}
+
+static const struct i2c_device_id mcp9982_id[] = {
+ { .name = "mcp9933", .driver_data = (kernel_ulong_t)&mcp9933_chip_config },
+ { .name = "mcp9933d", .driver_data = (kernel_ulong_t)&mcp9933d_chip_config },
+ { .name = "mcp9982", .driver_data = (kernel_ulong_t)&mcp9982_chip_config },
+ { .name = "mcp9982d", .driver_data = (kernel_ulong_t)&mcp9982d_chip_config },
+ { .name = "mcp9983", .driver_data = (kernel_ulong_t)&mcp9983_chip_config },
+ { .name = "mcp9983d", .driver_data = (kernel_ulong_t)&mcp9983d_chip_config },
+ { .name = "mcp9984", .driver_data = (kernel_ulong_t)&mcp9984_chip_config },
+ { .name = "mcp9984d", .driver_data = (kernel_ulong_t)&mcp9984d_chip_config },
+ { .name = "mcp9985", .driver_data = (kernel_ulong_t)&mcp9985_chip_config },
+ { .name = "mcp9985d", .driver_data = (kernel_ulong_t)&mcp9985d_chip_config },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, mcp9982_id);
+
+static const struct of_device_id mcp9982_of_match[] = {
+ {
+ .compatible = "microchip,mcp9933",
+ .data = &mcp9933_chip_config,
+ }, {
+ .compatible = "microchip,mcp9933d",
+ .data = &mcp9933d_chip_config,
+ }, {
+ .compatible = "microchip,mcp9982",
+ .data = &mcp9982_chip_config,
+ }, {
+ .compatible = "microchip,mcp9982d",
+ .data = &mcp9982d_chip_config,
+ }, {
+ .compatible = "microchip,mcp9983",
+ .data = &mcp9983_chip_config,
+ }, {
+ .compatible = "microchip,mcp9983d",
+ .data = &mcp9983d_chip_config,
+ }, {
+ .compatible = "microchip,mcp9984",
+ .data = &mcp9984_chip_config,
+ }, {
+ .compatible = "microchip,mcp9984d",
+ .data = &mcp9984d_chip_config,
+ }, {
+ .compatible = "microchip,mcp9985",
+ .data = &mcp9985_chip_config,
+ }, {
+ .compatible = "microchip,mcp9985d",
+ .data = &mcp9985d_chip_config,
+ },
+ { }
+};
+MODULE_DEVICE_TABLE(of, mcp9982_of_match);
+
+static struct i2c_driver mcp9982_driver = {
+ .driver = {
+ .name = "mcp9982",
+ .of_match_table = mcp9982_of_match,
+ },
+ .probe = mcp9982_probe,
+ .id_table = mcp9982_id,
+};
+module_i2c_driver(mcp9982_driver);
+
+MODULE_AUTHOR("Victor Duicu <victor.duicu@microchip.com>");
+MODULE_DESCRIPTION("MCP998X/33 and MCP998XD/33D Multichannel Automotive Temperature Monitor Driver");
+MODULE_LICENSE("GPL");
--
2.48.1
^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH v6 2/2] iio: temperature: add support for MCP998X
2025-09-30 13:31 ` [PATCH v6 2/2] " victor.duicu
@ 2025-10-02 0:13 ` kernel test robot
2025-10-04 14:17 ` Jonathan Cameron
1 sibling, 0 replies; 7+ messages in thread
From: kernel test robot @ 2025-10-02 0:13 UTC (permalink / raw)
To: victor.duicu, jic23, dlechner, nuno.sa, andy, robh, krzk+dt,
conor+dt
Cc: oe-kbuild-all, marius.cristea, victor.duicu, linux-iio,
linux-kernel, devicetree
Hi,
kernel test robot noticed the following build errors:
[auto build test ERROR on 561285d048053fec8a3d6d1e3ddc60df11c393a0]
url: https://github.com/intel-lab-lkp/linux/commits/victor-duicu-microchip-com/dt-bindings-iio-temperature-add-support-for-MCP998X/20250930-213443
base: 561285d048053fec8a3d6d1e3ddc60df11c393a0
patch link: https://lore.kernel.org/r/20250930133131.13797-3-victor.duicu%40microchip.com
patch subject: [PATCH v6 2/2] iio: temperature: add support for MCP998X
config: i386-randconfig-013-20251002 (https://download.01.org/0day-ci/archive/20251002/202510020803.3pQv1jeZ-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.4.0-5) 12.4.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251002/202510020803.3pQv1jeZ-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202510020803.3pQv1jeZ-lkp@intel.com/
All errors (new ones prefixed by >>):
drivers/iio/temperature/mcp9982.c: In function 'mcp9982_read_raw':
>> drivers/iio/temperature/mcp9982.c:467:24: error: implicit declaration of function 'get_unaligned_be16' [-Werror=implicit-function-declaration]
467 | *val = get_unaligned_be16(bulk_read + 1);
| ^~~~~~~~~~~~~~~~~~
cc1: some warnings being treated as errors
vim +/get_unaligned_be16 +467 drivers/iio/temperature/mcp9982.c
416
417 static int mcp9982_read_raw(struct iio_dev *indio_dev,
418 struct iio_chan_spec const *chan, int *val,
419 int *val2, long mask)
420 {
421 unsigned int tmp_reg, reg_status;
422 struct mcp9982_priv *priv = iio_priv(indio_dev);
423 unsigned long *src;
424 int ret;
425 u8 bulk_read[3];
426
427 if (priv->run_state) {
428 /*
429 * When working in Run mode, after modifying a parameter (like sampling
430 * frequency) we have to wait a delay before reading the new values.
431 * We can't determine when the conversion is done based on the BUSY bit.
432 */
433 if (priv->wait_before_read) {
434 if (!time_after(jiffies, priv->time_limit))
435 mdelay(jiffies_to_msecs(priv->time_limit - jiffies));
436 priv->wait_before_read = false;
437 }
438 } else {
439 ret = regmap_write(priv->regmap, MCP9982_ONE_SHOT_ADDR, 1);
440 if (ret)
441 return ret;
442 /*
443 * In Standby state after writing in OneShot register wait for
444 * the start of conversion and then poll the BUSY bit.
445 */
446 mdelay(125);
447 ret = regmap_read_poll_timeout(priv->regmap, MCP9982_STATUS_ADDR,
448 reg_status, !(reg_status & MCP9982_STATUS_BUSY),
449 mcp9982_delay_ms[priv->sampl_idx] * USEC_PER_MSEC,
450 0);
451 if (ret)
452 return ret;
453 }
454 guard(mutex)(&priv->lock);
455
456 switch (mask) {
457 case IIO_CHAN_INFO_RAW:
458 /*
459 * The Block Read Protocol first returns the number of user readable
460 * bytes, held in bulk_read[0], followed by the data.
461 */
462 ret = regmap_bulk_read(priv->regmap, MCP9982_TEMP_MEM_BLOCK_ADDR(chan->channel),
463 &bulk_read, sizeof(bulk_read));
464 if (ret)
465 return ret;
466
> 467 *val = get_unaligned_be16(bulk_read + 1);
468
469 return IIO_VAL_INT;
470 case IIO_CHAN_INFO_SCALE:
471 *val = 0;
472 *val2 = MCP9982_SCALE;
473 return IIO_VAL_INT_PLUS_NANO;
474 case IIO_CHAN_INFO_SAMP_FREQ:
475 *val = mcp9982_conv_rate[priv->sampl_idx][0];
476 *val2 = mcp9982_conv_rate[priv->sampl_idx][1];
477 return IIO_VAL_INT_PLUS_MICRO;
478 case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
479 ret = regmap_read(priv->regmap, MCP9982_RUNNING_AVG_ADDR, &tmp_reg);
480 if (ret)
481 return ret;
482 *src = tmp_reg;
483 *val = mcp9982_3db_values_map_tbl[priv->sampl_idx][bitmap_weight(src, 2)][0];
484 *val2 = mcp9982_3db_values_map_tbl[priv->sampl_idx][bitmap_weight(src, 2)][1];
485 return IIO_VAL_INT_PLUS_MICRO;
486 case IIO_CHAN_INFO_OFFSET:
487 *val = MCP9982_OFFSET;
488 return IIO_VAL_INT;
489 default:
490 return -EINVAL;
491 }
492 }
493
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v6 0/2] add support for MCP998X
2025-09-30 13:31 [PATCH v6 0/2] add support for MCP998X victor.duicu
2025-09-30 13:31 ` [PATCH v6 1/2] dt-bindings: iio: temperature: " victor.duicu
2025-09-30 13:31 ` [PATCH v6 2/2] " victor.duicu
@ 2025-10-04 14:11 ` Jonathan Cameron
2025-10-04 14:29 ` Guenter Roeck
2 siblings, 1 reply; 7+ messages in thread
From: Jonathan Cameron @ 2025-10-04 14:11 UTC (permalink / raw)
To: victor.duicu
Cc: dlechner, nuno.sa, andy, robh, krzk+dt, conor+dt, marius.cristea,
linux-iio, linux-kernel, devicetree, Jean Delvare, Guenter Roeck
On Tue, 30 Sep 2025 16:31:29 +0300
<victor.duicu@microchip.com> wrote:
> From: Victor Duicu <victor.duicu@microchip.com>
>
> Add support for Microchip MCP998X/33 and MCP998XD/33D Multichannel
> Automotive Temperature Monitor Family.
>
> The chips in the family have different numbers of external channels,
> ranging from 1 (MCP9982) to 4 channels (MCP9985). Reading diodes in
> anti-parallel connection is supported by MCP9984/85/33 and
> MCP9984D/85D/33D. Dedicated hardware shutdown circuitry is present
> only in MCP998XD and MCP9933D.
>
> This driver was submitted in the IIO subsystem because the chips could use
> interrupts to handle threshold events.
This reasoning isn't particularly strong as hwmon has support for events etc.
This device is also 'slow' so I'm not immediately seeing a strong reason why
IIO is the right choice.
After some recent feedback from Guenter I'm keen to get a clearer set
of reasoning when I take a temperature monitoring chip into IIO.
Also asking that we +CC Guenter for his input on devices where the decision
isn't clear cut.
So +CC Guenter (and Jean as the other hwmon maintainer).
Apologies if I didn't explicitly request Guenter be +CC on earlier versions.
Thanks,
Jonathan
> Each chip supports 3 user.
> programmable limits per channel. The family is also capable of detecting
> hottest diode and diode faults.
> These features will be added in future patches.
>
> Differences related to previous patch:
> v6:
> - in yaml first condition list part numbers instead
> of regular expression. Add ^ to regular expression.
> - edit coding style and comments.
> - use hex values in defines.
> - remove MCP9982_TEMP_MEM_BLOCK_LOW and
> MCP9982_TEMP_MEM_BLOCK_HIGH.
> - in MCP9982_CHAN() place macro parameters in ().
> - move all variable definitions at the start of functions.
> - in mcp9982_parse_fw_config() initialise iio_idx to 0.
> - remove bit flags.
> - in MCP9982_CHAN remove outer ().
> - remove variable start in mcp9982_write_raw().
> - replace constant in .max_register.
> - use get_unaligned_be16 in mcp9982_read_raw().
>
> v5:
> - in yaml edit description of interrupts.
> - add min and maxItems to reg.
> - remove ideality parameter.
> - use pattern recognition in conditionals.
> - group conditions based on the chip.
> - correct microchip,parasitic-res-on-channel3-4 to true.
> - in driver include bitops.h.
> - change name of some variables.
> - rename mcp9982_parse_of_config() to mcp9982_parse_fw_config().
> - implement bulk reading of temp registers.
> - lock ideality parameter to default value.
> - implement bit flags.
> - add compound literal to MCP9982_CHAN.
> - remove hysteresis parameter.
> - edit comments.
> - change values from int to bool in mcp9982_features.
> - remove mcp9982_calc_all_3db_values() and hardcode values.
> When filter is OFF the 3db value is equal to frequency.
> - add .max_register to regmap_config.
> - remove devm_kcalloc().
> - in mcp9982_read_avail() add an else branch to hw_thermal_shutdown
> check.
> - in mcp9982_read_raw use USEC_PER_MSEC and set regmap_read_poll_timeout
> to never timeout.
> Replace switch with bitmap_weight.
> - in mcp9982_read_label() remove unnecessary if.
> - in mcp9982_write_raw() remove duplicated code.
> - in mcp9982_init add error messages when APDD and RECD are incorrectly
> set.
> - in mcp9982_parse_fw_config() add default for reg_nr.
>
> v4:
> - lock beta parameters to default value of beta-autodetect.
> Remove beta parameters and checks from devicetree.
> - lock temperature range to extended.
> This change avoids the issue of the average filter using raw values
> with different scales when changing the range.
> - change driver to wait an amount of time before reading a raw value
> to ensure it is valid.
> - change driver to stop calculating the physical temp when reading
> in_tempx_raw. Reading from in_tempx_raw will return the raw value.
> The physical temp will be calculated with in_tempx_raw, scale and
> offset parameters.
> - add scale parameter to channel definition.
> - initialise chips with "D" to work in Run state and those without
> in Standby state.
> - when activating the low pass filter for chips without "D",
> set the power state to RUN to ensure fresh values for the average.
> - add minimum and maximum to microchip,beta1 and microchip,beta2 in yaml.
> - rename microchip,resistance-comp-ch1-2-enable and
> microchip,resistance-comp-ch3-4-enable to
> microchip,parasitic-res-on-channel1-2
> and microchip,parasitic-res-on-channel3-4
> and edit description in yaml.
> - add conditional logic to check if the chip supports APDD
> and force default values where necessary in yaml.
> - edit comments and coding style.
> - replace asm/div64.h with linux/math64.h.
> - add delay.h to includes.
> - redefine mcp9982_sampl_fr with new structure division.
> - in mcp9982_priv remove dev_name,extended_temp_range and beta_values.
> Add run_state, wait_before_read, time_limit and pointer to chip
> structure to remove all instances of matching strings.
> Reorder parameters for memory optimization.
> - in mcp9982_features add flags to know if the chip has thermal shutdown
> circuitry and supports APDD.
> - in mcp9982_read_avail() rework verification of chip type in sampling
> frequency case.
> - in mcp9982_read_raw() rework switch in low pass filter case.
> - in mcp9982_parse_of_config() replace generic -EINVAL code
> with -E2BIG and -EOVERFLOW.
>
> v3:
> - move beta parameters to devicetree.
> - change the name of the interrupts and add
> check to match them to the device in yaml.
> - remove label for device and remove "0x" from
> channel registers in example in yaml.
> - edit comments in yaml and driver.
> - add minItems to interrupts in yaml.
> - rename microchip,recd12 and microchip,recd34 to
> microchip,resistance-comp-ch1-2-enable
> and microchip,resistance-comp-ch3-4-enable.
> - rename microchip,apdd-state to microchip,enable-anti-parallel.
> - add static to mcp9982_3db_values_map_tbl to fix
> kernel test robot warning.
> - in mcp9982_init() add check to ensure that hardware
> shutdown feature can't be overridden.
> - replace div_u64_rem with do_div and add
> asm/div64.h to includes.
> - remove unused includes.
> - add iio_chan_spec in the macro definition of MCP9982_CHAN.
> - remove MCP9982_EXT_BETA_ENBL.
> - in mcp9982_init() replace regmap_assign_bits
> with regmap_write when setting beta compensation.
> - remove custom attribute enable_extended_temp_range and
> map it to IIO_CHAN_INFO_OFFSET.
> - add unsigned to int variables that allow it.
> - reorder parameters in mcp9982_priv, change some
> from int to bool, add const to labels and add dev_name.
> - add check for chips with "D" in the name to not
> allow sampling frequencies lower than 1 to
> prevent overriding of hardware shutdown.
> - remove mcp9982_attributes.
> - move mcp9982_calc_all_3db_values() to before
> mcp9982_init().
> - use MICRO instead of number constant.
> - in mcp9982_write_raw replace ">=" with "==".
> - rename index2 to idx in mcp9982_read_raw().
> - remove i2c_set_clientdata() in mcp9982_probe().
> - since there are no more custom ABI attributes
> the testing file was removed.
>
> v2:
> - move hysteresis, extended temperature range and beta parameters
> from devicetree into user space.
> - edit comments in yaml and driver.
> - remove "|" in descpriptions, remove "+" from PatternProperties in yaml.
> - add default to microchip,ideality-factor, delete blank lines and wrap to
> 80 chars in yaml.
> - remove variables with upper case.
> - add check for microchip,apdd-state and microchip,recd34 in yaml.
> - improve coding style in driver code.
> - add includes for all functions used.
> - rename MCP9982_INT_HIGH_BYTE_ADDR to MCP9982_INT_VALUE_ADDR and
> MCP9982_INT_LOW_BYTE_ADDR to MCP9982_FRAC_VALUE_ADDR.
> - remove custom attribute running_average_window and
> running_average_window_available and map them to a low pass filter.
> - update sysfs-bus-iio-temperature-mcp9982 to reflect current
> driver attributes and point to next kernel version (6.17).
> - use compound literal to define driver channels.
> - replace device_property_read_string() with i2c_get_match_data() to read
> chip name from devicetree.
> - remove MCP9982_DEV_ATTR and mcp9982_prep_custom_attributes().
> - remove client, chip_name, iio_info from mcp9982_priv.
> - replace sprintf() with sysfs_emit().
> - remove error messages which are triggered by keyboard input.
> - replace devm_kzalloc() with devm_kcalloc(), array mcp9982_chip_config[]
> with individual structures, device_property_present() with
> device_property_read_bool().
> - reordered parameters in mcp9982_features and mcp9982_priv to optimize
> memory allocation.
> - remove .endianness from channel properties.
> - change name of some parameters in mcp9982_priv.
> - add check for reg value 0 from devicetree (channel 0 is for internal
> temperature and can't be disabled).
>
> v1:
> - initial version.
>
> Victor Duicu (2):
> dt-bindings: iio: temperature: add support for MCP998X
> iio: temperature: add support for MCP998X
>
> .../iio/temperature/microchip,mcp9982.yaml | 190 ++++
> MAINTAINERS | 7 +
> drivers/iio/temperature/Kconfig | 10 +
> drivers/iio/temperature/Makefile | 1 +
> drivers/iio/temperature/mcp9982.c | 862 ++++++++++++++++++
> 5 files changed, 1070 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/iio/temperature/microchip,mcp9982.yaml
> create mode 100644 drivers/iio/temperature/mcp9982.c
>
>
> base-commit: 561285d048053fec8a3d6d1e3ddc60df11c393a0
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v6 2/2] iio: temperature: add support for MCP998X
2025-09-30 13:31 ` [PATCH v6 2/2] " victor.duicu
2025-10-02 0:13 ` kernel test robot
@ 2025-10-04 14:17 ` Jonathan Cameron
1 sibling, 0 replies; 7+ messages in thread
From: Jonathan Cameron @ 2025-10-04 14:17 UTC (permalink / raw)
To: victor.duicu
Cc: dlechner, nuno.sa, andy, robh, krzk+dt, conor+dt, marius.cristea,
linux-iio, linux-kernel, devicetree
On Tue, 30 Sep 2025 16:31:31 +0300
<victor.duicu@microchip.com> wrote:
> From: Victor Duicu <victor.duicu@microchip.com>
>
> This is the driver for Microchip MCP998X/33 and MCP998XD/33D Multichannel
> Automotive Temperature Monitor Family.
>
> Signed-off-by: Victor Duicu <victor.duicu@microchip.com>
Other than the request for a stronger set of reasoning for IIO rather than
hwmon this looks good to me.
We have plenty of time given where we are in the cycle to resolve that
question.
Thanks,
Jonathan
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v6 0/2] add support for MCP998X
2025-10-04 14:11 ` [PATCH v6 0/2] " Jonathan Cameron
@ 2025-10-04 14:29 ` Guenter Roeck
0 siblings, 0 replies; 7+ messages in thread
From: Guenter Roeck @ 2025-10-04 14:29 UTC (permalink / raw)
To: Jonathan Cameron, victor.duicu
Cc: dlechner, nuno.sa, andy, robh, krzk+dt, conor+dt, marius.cristea,
linux-iio, linux-kernel, devicetree, Jean Delvare
On 10/4/25 07:11, Jonathan Cameron wrote:
> On Tue, 30 Sep 2025 16:31:29 +0300
> <victor.duicu@microchip.com> wrote:
>
>> From: Victor Duicu <victor.duicu@microchip.com>
>>
>> Add support for Microchip MCP998X/33 and MCP998XD/33D Multichannel
>> Automotive Temperature Monitor Family.
>>
>> The chips in the family have different numbers of external channels,
>> ranging from 1 (MCP9982) to 4 channels (MCP9985). Reading diodes in
>> anti-parallel connection is supported by MCP9984/85/33 and
>> MCP9984D/85D/33D. Dedicated hardware shutdown circuitry is present
>> only in MCP998XD and MCP9933D.
>>
>> This driver was submitted in the IIO subsystem because the chips could use
>> interrupts to handle threshold events.
>
> This reasoning isn't particularly strong as hwmon has support for events etc.
> This device is also 'slow' so I'm not immediately seeing a strong reason why
> IIO is the right choice.
>
Correct. hwmon supports both events and udev events.
> After some recent feedback from Guenter I'm keen to get a clearer set
> of reasoning when I take a temperature monitoring chip into IIO.
>
> Also asking that we +CC Guenter for his input on devices where the decision
> isn't clear cut.
IMO this _is_ (or should be) clear cut: This is a hardware monitoring device.
It should be a hardware monitoring driver. FWIW, writing one should be
straightforward (including interrupt/event support).
Guenter
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2025-10-04 14:29 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2025-09-30 13:31 [PATCH v6 0/2] add support for MCP998X victor.duicu
2025-09-30 13:31 ` [PATCH v6 1/2] dt-bindings: iio: temperature: " victor.duicu
2025-09-30 13:31 ` [PATCH v6 2/2] " victor.duicu
2025-10-02 0:13 ` kernel test robot
2025-10-04 14:17 ` Jonathan Cameron
2025-10-04 14:11 ` [PATCH v6 0/2] " Jonathan Cameron
2025-10-04 14:29 ` Guenter Roeck
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