[PATCH v4 2/2] iio: adc: adding support for MCP3564 ADC
From: marius.cristea
Date: Fri Aug 18 2023 - 12:59:19 EST
From: Marius Cristea <marius.cristea@xxxxxxxxxxxxx>
This is the iio driver for Microchip family of 153.6 ksps,
Low-Noise 16/24-Bit Delta-Sigma ADCs with an SPI interface
(Microchip's MCP3461, MCP3462, MCP3464, MCP3461R, MCP3462R,
MCP3464R, MCP3561, MCP3562, MCP3564, MCP3561R,
MCP3562R and MCP3564R analog to digital converters).
Signed-off-by: Marius Cristea <marius.cristea@xxxxxxxxxxxxx>
---
.../ABI/testing/sysfs-bus-iio-adc-mcp3564 | 53 +
MAINTAINERS | 7 +
drivers/iio/adc/Kconfig | 13 +
drivers/iio/adc/Makefile | 1 +
drivers/iio/adc/mcp3564.c | 1527 +++++++++++++++++
5 files changed, 1601 insertions(+)
create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-adc-mcp3564
create mode 100644 drivers/iio/adc/mcp3564.c
diff --git a/Documentation/ABI/testing/sysfs-bus-iio-adc-mcp3564 b/Documentation/ABI/testing/sysfs-bus-iio-adc-mcp3564
new file mode 100644
index 000000000000..4d6b1f40e277
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-bus-iio-adc-mcp3564
@@ -0,0 +1,53 @@
+What: /sys/bus/iio/devices/iio:deviceX/boost_current_gain
+KernelVersion: 6.4
+Contact: linux-iio@xxxxxxxxxxxxxxx
+Description:
+ This attribute is used to set the gain of the biasing current
+ circuit of the Delta-Sigma modulator. The different BOOST
+ settings are applied to the entire modulator circuit, including
+ the voltage reference buffers.
+
+What: /sys/bus/iio/devices/iio:deviceX/boost_current_gain_available
+KernelVersion: 6.4
+Contact: linux-iio@xxxxxxxxxxxxxxx
+Description:
+ Reading returns a list with the possible gain values for
+ the current biasing circuit of the Delta-Sigma modulator.
+
+What: /sys/bus/iio/devices/iio:deviceX/auto_zeroing_mux_enable
+KernelVersion: 6.4
+Contact: linux-iio@xxxxxxxxxxxxxxx
+Description:
+ This attribute is used to enable the analog input multiplexer
+ auto-zeroing algorithm (the input multiplexer and the ADC
+ include an offset cancellation algorithm that cancels the offset
+ contribution of the ADC). When the offset cancellation algorithm
+ is enabled, ADC takes two conversions, one with the differential
+ input as VIN+/VIN-, one with VIN+/VIN- inverted. In this case the
+ conversion time is multiplied by two compared to the default
+ case where the algorithm is disabled. This technique allows the
+ cancellation of the ADC offset error and the achievement of
+ ultra-low offset without any digital calibration. The resulting
+ offset is the residue of the difference between the two
+ conversions, which is on the order of magnitude of the noise
+ floor. This offset is effectively canceled at every conversion,
+ so the residual offset error temperature drift is extremely low.
+ Write '1' to enable it, write '0' to disable it.
+
+What: /sys/bus/iio/devices/iio:deviceX/auto_zeroing_ref_enable
+KernelVersion: 6.4
+Contact: linux-iio@xxxxxxxxxxxxxxx
+Description:
+ This attribute is used to enable the chopping algorithm for the
+ internal voltage reference buffer. This setting has no effect
+ when external voltage reference is selected.
+ Internal voltage reference buffer injects a certain quantity of
+ 1/f noise into the system that can be modulated with the
+ incoming input signals and can limit the SNR performance at
+ higher Oversampling Ratio values (over 256). To overcome this
+ limitation, the buffer includes an auto-zeroing algorithm that
+ greatly reduces (cancels out) the 1/f noise and cancels the
+ offset value of the reference buffer. As a result, the SNR of
+ the system is not affected by this 1/f noise component of the
+ reference buffer, even at maximum oversampling ratio values.
+ Write '1' to enable it, write '0' to disable it.
diff --git a/MAINTAINERS b/MAINTAINERS
index 6969a2962ffe..50c879f85e1e 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -13798,6 +13798,13 @@ S: Supported
F: Documentation/devicetree/bindings/regulator/mcp16502-regulator.txt
F: drivers/regulator/mcp16502.c
+MICROCHIP MCP3564 ADC DRIVER
+M: Marius Cristea <marius.cristea@xxxxxxxxxxxxx>
+L: linux-iio@xxxxxxxxxxxxxxx
+S: Supported
+F: Documentation/devicetree/bindings/iio/adc/microchip,mcp3564.yaml
+F: drivers/iio/adc/mcp3564.c
+
MICROCHIP MCP3911 ADC DRIVER
M: Marcus Folkesson <marcus.folkesson@xxxxxxxxx>
M: Kent Gustavsson <kent@xxxxxxxxxx>
diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 53098aca06ea..782bf5eec8ed 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -768,6 +768,19 @@ config MCP3422
This driver can also be built as a module. If so, the module will be
called mcp3422.
+config MCP3564
+ tristate "Microchip Technology MCP3461/2/4/R, MCP3561/2/4/R driver"
+ depends on SPI
+ depends on IIO
+ help
+ Say yes here to build support for Microchip Technology's MCP3461,
+ MCP3462, MCP3464, MCP3461R, MCP3462R, MCP3464R, MCP3561, MCP3562,
+ MCP3564, MCP3561R, MCP3562R and MCP3564R analog to digital
+ converters.
+
+ This driver can also be built as a module. If so, the module will be
+ called mcp3564.
+
config MCP3911
tristate "Microchip Technology MCP3911 driver"
depends on SPI
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index e07e4a3e6237..91f713af574f 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -70,6 +70,7 @@ obj-$(CONFIG_MAX1363) += max1363.o
obj-$(CONFIG_MAX9611) += max9611.o
obj-$(CONFIG_MCP320X) += mcp320x.o
obj-$(CONFIG_MCP3422) += mcp3422.o
+obj-$(CONFIG_MCP3564) += mcp3564.o
obj-$(CONFIG_MCP3911) += mcp3911.o
obj-$(CONFIG_MEDIATEK_MT6360_ADC) += mt6360-adc.o
obj-$(CONFIG_MEDIATEK_MT6370_ADC) += mt6370-adc.o
diff --git a/drivers/iio/adc/mcp3564.c b/drivers/iio/adc/mcp3564.c
new file mode 100644
index 000000000000..8c5649781093
--- /dev/null
+++ b/drivers/iio/adc/mcp3564.c
@@ -0,0 +1,1527 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * IIO driver for MCP356X/MCP356XR and MCP346X/MCP346XR series ADC chip family
+ *
+ * Copyright (C) 2022-2023 Microchip Technology Inc. and its subsidiaries
+ *
+ * Author: Marius Cristea <marius.cristea@xxxxxxxxxxxxx>
+ *
+ * Datasheet for MCP3561, MCP3562, MCP3564 can be found here:
+ * https://ww1.microchip.com/downloads/aemDocuments/documents/MSLD/ProductDocuments/DataSheets/MCP3561-2-4-Family-Data-Sheet-DS20006181C.pdf
+ * Datasheet for MCP3561R, MCP3562R, MCP3564R can be found here:
+ * https://ww1.microchip.com/downloads/aemDocuments/documents/APID/ProductDocuments/DataSheets/MCP3561_2_4R-Data-Sheet-DS200006391C.pdf
+ * Datasheet for MCP3461, MCP3462, MCP3464 can be found here:
+ * https://ww1.microchip.com/downloads/aemDocuments/documents/APID/ProductDocuments/DataSheets/MCP3461-2-4-Two-Four-Eight-Channel-153.6-ksps-Low-Noise-16-Bit-Delta-Sigma-ADC-Data-Sheet-20006180D.pdf
+ * Datasheet for MCP3461R, MCP3462R, MCP3464R can be found here:
+ * https://ww1.microchip.com/downloads/aemDocuments/documents/APID/ProductDocuments/DataSheets/MCP3461-2-4R-Family-Data-Sheet-DS20006404C.pdf
+ */
+
+#include <linux/bitfield.h>
+#include <linux/iopoll.h>
+#include <linux/regulator/consumer.h>
+#include <linux/spi/spi.h>
+#include <linux/units.h>
+#include <linux/util_macros.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+
+#define MCP3564_ADCDATA_REG 0x00
+
+#define MCP3564_CONFIG0_REG 0x01
+#define MCP3564_CONFIG0_ADC_MODE_MASK GENMASK(1, 0)
+#define MCP3564_CONFIG0_ADC_MODE_MASK_SET(x) FIELD_PREP(MCP3564_CONFIG0_ADC_MODE_MASK, (x))
+/* Current Source/Sink Selection Bits for Sensor Bias */
+#define MCP3564_CONFIG0_CS_SEL_MASK GENMASK(3, 2)
+#define MCP3564_CONFIG0_CS_SEL_SET(x) FIELD_PREP(MCP3564_CONFIG0_CS_SEL_MASK, (x))
+/* Internal clock is selected and AMCLK is present on the analog master clock output pin */
+#define MCP3564_CONFIG0_USE_INT_CLK_OUTPUT_EN 0x03
+/* Internal clock is selected and no clock output is present on the CLK pin */
+#define MCP3564_CONFIG0_USE_INT_CLK 0x02
+/* External digital clock */
+#define MCP3564_CONFIG0_USE_EXT_CLK 0x01
+/* External digital clock (default) */
+#define MCP3564_CONFIG0_USE_EXT_CLK_DEFAULT 0x00
+#define MCP3564_CONFIG0_CLK_SEL_MASK GENMASK(5, 4)
+#define MCP3564_CONFIG0_CLK_SEL_SET(x) FIELD_PREP(MCP3564_CONFIG0_CLK_SEL_MASK, (x))
+#define MCP3456_CONFIG0_BIT6_DEFAULT BIT(6)
+#define MCP3456_CONFIG0_VREF_MASK BIT(7)
+#define MCP3564_CONFIG0_VREF_SET(x) FIELD_PREP(MCP3456_CONFIG0_VREF_MASK, (x))
+
+#define MCP3564_CONFIG1_REG 0x02
+#define MCP3564_CONFIG1_OVERSPL_RATIO_MASK GENMASK(5, 2)
+#define MCP3564_CONFIG1_OVERSPL_RATIO_SET(x) FIELD_PREP(MCP3564_CONFIG1_OVERSPL_RATIO_MASK, (x))
+
+#define MCP3564_CONFIG2_REG 0x03
+#define MCP3564_CONFIG2_AZ_REF_MASK BIT(1)
+#define MCP3564_CONFIG2_AZ_REF_SET(x) FIELD_PREP(MCP3564_CONFIG2_AZ_REF_MASK, (x))
+#define MCP3564_CONFIG2_AZ_MUX_MASK BIT(2)
+#define MCP3564_CONFIG2_AZ_MUX_SET(x) FIELD_PREP(MCP3564_CONFIG2_AZ_MUX_MASK, (x))
+
+#define MCP3564_CONFIG2_HARDWARE_GAIN_MASK GENMASK(5, 3)
+#define MCP3564_CONFIG2_HARDWARE_GAIN_SET(x) FIELD_PREP(MCP3564_CONFIG2_HARDWARE_GAIN_MASK, (x))
+#define MCP3564_DEFAULT_HARDWARE_GAIN 0x01
+#define MCP3564_CONFIG2_BOOST_CURRENT_MASK GENMASK(7, 6)
+#define MCP3564_CONFIG2_BOOST_CURRENT_SET(x) FIELD_PREP(MCP3564_CONFIG2_BOOST_CURRENT_MASK, (x))
+
+#define MCP3564_CONFIG3_REG 0x04
+#define MCP3464_CONFIG3_EN_GAINCAL_MASK BIT(0)
+#define MCP3464_CONFIG3_EN_OFFCAL_MASK BIT(1)
+#define MCP3464_CONFIG3_EN_CRCCOM_MASK BIT(2)
+#define MCP3464_CONFIG3_CRC_FORMAT_MASK BIT(3)
+/*
+ * ADC Output Data Format 32-bit (25-bit right justified data + Channel ID):
+ * CHID[3:0] + SGN extension (4 bits) + 24-bit ADC data.
+ * It allows overrange with the SGN extension.
+ */
+#define MCP3464_CONFIG3_DATA_FMT_32B_WITH_CH_ID 3
+/*
+ * ADC Output Data Format 32-bit (25-bit right justified data):
+ * SGN extension (8-bit) + 24-bit ADC data.
+ * It allows overrange with the SGN extension.
+ */
+#define MCP3464_CONFIG3_DATA_FMT_32B_SGN_EXT 2
+/*
+ * ADC Output Data Format 32-bit (24-bit left justified data):
+ * 24-bit ADC data + 0x00 (8-bit).
+ * It does not allow overrange (ADC code locked to 0xFFFFFF or 0x800000).
+ */
+#define MCP3464_CONFIG3_DATA_FMT_32B_LEFT_JUSTIFIED 1
+/*
+ * ADC Output Data Format 24-bit (default ADC coding):
+ * 24-bit ADC data.
+ * It does not allow overrange (ADC code locked to 0xFFFFFF or 0x800000).
+ */
+#define MCP3464_CONFIG3_DATA_FMT_24B 0
+#define MCP3464_CONFIG3_DATA_FORMAT_MASK GENMASK(5, 4)
+#define MCP3564_CONFIG3_DATA_FORMAT_SET(x) FIELD_PREP(MCP3464_CONFIG3_DATA_FORMAT_MASK, (x))
+
+/* 0b11 = Continuous Conversion mode or continuous conversion cycle in SCAN mode. */
+#define MCP3464_CONFIG3_CONV_MODE_CONTINUOUS 3
+/*
+ * 0b10 = One-shot conversion or one-shot cycle in SCAN mode. It sets ADC_MODE[1:0] to ‘10’
+ * (standby) at the end of the conversion or at the end of the conversion cycle in SCAN mode.
+ */
+#define MCP3464_CONFIG3_CONV_MODE_ONE_SHOT_STANDBY 2
+/*
+ * 0b0x = One-shot conversion or one-shot cycle in SCAN mode. It sets ADC_MODE[1:0] to ‘0x’ (ADC
+ * Shutdown) at the end of the conversion or at the end of the conversion cycle in SCAN
+ * mode (default).
+ */
+#define MCP3464_CONFIG3_CONV_MODE_ONE_SHOT_SHUTDOWN 0
+#define MCP3464_CONFIG3_CONV_MODE_MASK GENMASK(7, 6)
+#define MCP3564_CONFIG3_CONV_MODE_SET(x) FIELD_PREP(MCP3464_CONFIG3_CONV_MODE_MASK, (x))
+
+#define MCP3564_IRQ_REG 0x05
+#define MCP3464_EN_STP_MASK BIT(0)
+#define MCP3464_EN_FASTCMD_MASK BIT(1)
+#define MCP3464_IRQ_MODE_0_MASK BIT(2)
+#define MCP3464_IRQ_MODE_1_MASK BIT(3)
+#define MCP3564_POR_STATUS_MASK BIT(4)
+#define MCP3564_CRCCFG_STATUS_MASK BIT(5)
+#define MCP3564_DATA_READY_MASK BIT(6)
+
+#define MCP3564_MUX_REG 0x06
+#define MCP3564_MUX_VIN_P_MASK GENMASK(7, 4)
+#define MCP3564_MUX_VIN_N_MASK GENMASK(3, 0)
+#define MCP3564_MUX_SET(x, y) (FIELD_PREP(MCP3564_MUX_VIN_P_MASK, (x)) | \
+ FIELD_PREP(MCP3564_MUX_VIN_N_MASK, (y)))
+
+#define MCP3564_SCAN_REG 0x07
+#define MCP3564_SCAN_CH_SEL_MASK GENMASK(15, 0)
+#define MCP3564_SCAN_CH_SEL_SET(x) FIELD_PREP(MCP3564_SCAN_CH_SEL_MASK, (x))
+#define MCP3564_SCAN_DELAY_TIME_MASK GENMASK(23, 21)
+#define MCP3564_SCAN_DELAY_TIME_SET(x) FIELD_PREP(MCP3564_SCAN_DELAY_TIME_MASK, (x))
+#define MCP3564_SCAN_DEFAULT_VALUE 0
+
+#define MCP3564_TIMER_REG 0x08
+#define MCP3564_TIMER_DEFAULT_VALUE 0
+
+#define MCP3564_OFFSETCAL_REG 0x09
+#define MCP3564_DEFAULT_OFFSETCAL 0
+
+#define MCP3564_GAINCAL_REG 0x0A
+#define MCP3564_DEFAULT_GAINCAL 0x00800000
+
+#define MCP3564_RESERVED_B_REG 0x0B
+
+#define MCP3564_RESERVED_C_REG 0x0C
+#define MCP3564_C_REG_DEFAULT 0x50
+#define MCP3564R_C_REG_DEFAULT 0x30
+
+#define MCP3564_LOCK_REG 0x0D
+#define MCP3564_LOCK_WRITE_ACCESS_PASSWORD 0xA5
+#define MCP3564_RESERVED_E_REG 0x0E
+#define MCP3564_CRCCFG_REG 0x0F
+
+#define MCP3564_CMD_HW_ADDR_MASK GENMASK(7, 6)
+#define MCP3564_CMD_HW_ADDR_SET(x) FIELD_PREP(MCP3564_CMD_HW_ADDR_MASK, (x))
+#define MCP3564_CMD_ADDR_MASK GENMASK(5, 2)
+#define MCP3564_CMD_ADDR_SET(x) FIELD_PREP(MCP3564_CMD_ADDR_MASK, (x))
+
+#define MCP3564_HW_ADDR_MASK GENMASK(1, 0)
+
+#define MCP3564_FASTCMD_START 0x0A
+#define MCP3564_FASTCMD_RESET 0x0E
+
+#define MCP3461_HW_ID 0x0008
+#define MCP3462_HW_ID 0x0009
+#define MCP3464_HW_ID 0x000B
+
+#define MCP3561_HW_ID 0x000C
+#define MCP3562_HW_ID 0x000D
+#define MCP3564_HW_ID 0x000F
+#define MCP3564_HW_ID_MASK GENMASK(3, 0)
+
+#define MCP3564R_INT_VREF_MV 2400
+
+#define MCP3564_DATA_READY_TIMEOUT_MS 2000
+
+#define MCP3564_MAX_PGA 8
+#define MCP3564_MAX_BURNOUT_IDX 4
+#define MCP3564_MAX_CHANNELS 66
+
+enum mcp3564_ids {
+ mcp3461,
+ mcp3462,
+ mcp3464,
+ mcp3561,
+ mcp3562,
+ mcp3564,
+ mcp3461r,
+ mcp3462r,
+ mcp3464r,
+ mcp3561r,
+ mcp3562r,
+ mcp3564r,
+};
+
+enum mcp3564_delay_time {
+ MCP3564_NO_DELAY,
+ MCP3564_DELAY_8_DMCLK,
+ MCP3564_DELAY_16_DMCLK,
+ MCP3564_DELAY_32_DMCLK,
+ MCP3564_DELAY_64_DMCLK,
+ MCP3564_DELAY_128_DMCLK,
+ MCP3564_DELAY_256_DMCLK,
+ MCP3564_DELAY_512_DMCLK
+};
+
+enum mcp3564_adc_conversion_mode {
+ MCP3564_ADC_MODE_DEFAULT,
+ MCP3564_ADC_MODE_SHUTDOWN,
+ MCP3564_ADC_MODE_STANDBY,
+ MCP3564_ADC_MODE_CONVERSION
+};
+
+enum mcp3564_adc_bias_current {
+ MCP3564_BOOST_CURRENT_x0_50,
+ MCP3564_BOOST_CURRENT_x0_66,
+ MCP3564_BOOST_CURRENT_x1_00,
+ MCP3564_BOOST_CURRENT_x2_00
+};
+
+enum mcp3564_burnout {
+ MCP3564_CONFIG0_CS_SEL_0_0_uA,
+ MCP3564_CONFIG0_CS_SEL_0_9_uA,
+ MCP3564_CONFIG0_CS_SEL_3_7_uA,
+ MCP3564_CONFIG0_CS_SEL_15_uA
+};
+
+enum mcp3564_channel_names {
+ MCP3564_CH0,
+ MCP3564_CH1,
+ MCP3564_CH2,
+ MCP3564_CH3,
+ MCP3564_CH4,
+ MCP3564_CH5,
+ MCP3564_CH6,
+ MCP3564_CH7,
+ MCP3564_AGND,
+ MCP3564_AVDD,
+ MCP3564_RESERVED, /* do not use */
+ MCP3564_REFIN_POZ,
+ MCP3564_REFIN_NEG,
+ MCP3564_TEMP_DIODE_P,
+ MCP3564_TEMP_DIODE_M,
+ MCP3564_INTERNAL_VCM,
+};
+
+enum mcp3564_oversampling {
+ MCP3564_OVERSAMPLING_RATIO_32,
+ MCP3564_OVERSAMPLING_RATIO_64,
+ MCP3564_OVERSAMPLING_RATIO_128,
+ MCP3564_OVERSAMPLING_RATIO_256,
+ MCP3564_OVERSAMPLING_RATIO_512,
+ MCP3564_OVERSAMPLING_RATIO_1024,
+ MCP3564_OVERSAMPLING_RATIO_2048,
+ MCP3564_OVERSAMPLING_RATIO_4096,
+ MCP3564_OVERSAMPLING_RATIO_8192,
+ MCP3564_OVERSAMPLING_RATIO_16384,
+ MCP3564_OVERSAMPLING_RATIO_20480,
+ MCP3564_OVERSAMPLING_RATIO_24576,
+ MCP3564_OVERSAMPLING_RATIO_40960,
+ MCP3564_OVERSAMPLING_RATIO_49152,
+ MCP3564_OVERSAMPLING_RATIO_81920,
+ MCP3564_OVERSAMPLING_RATIO_98304
+};
+
+static const unsigned int mcp3564_oversampling_avail[] = {
+ [MCP3564_OVERSAMPLING_RATIO_32] = 32,
+ [MCP3564_OVERSAMPLING_RATIO_64] = 64,
+ [MCP3564_OVERSAMPLING_RATIO_128] = 128,
+ [MCP3564_OVERSAMPLING_RATIO_256] = 256,
+ [MCP3564_OVERSAMPLING_RATIO_512] = 512,
+ [MCP3564_OVERSAMPLING_RATIO_1024] = 1024,
+ [MCP3564_OVERSAMPLING_RATIO_2048] = 2048,
+ [MCP3564_OVERSAMPLING_RATIO_4096] = 4096,
+ [MCP3564_OVERSAMPLING_RATIO_8192] = 8192,
+ [MCP3564_OVERSAMPLING_RATIO_16384] = 16384,
+ [MCP3564_OVERSAMPLING_RATIO_20480] = 20480,
+ [MCP3564_OVERSAMPLING_RATIO_24576] = 24576,
+ [MCP3564_OVERSAMPLING_RATIO_40960] = 40960,
+ [MCP3564_OVERSAMPLING_RATIO_49152] = 49152,
+ [MCP3564_OVERSAMPLING_RATIO_81920] = 81920,
+ [MCP3564_OVERSAMPLING_RATIO_98304] = 98304
+};
+
+/*
+ * Current Source/Sink Selection Bits for Sensor Bias (source on VIN+/sink on VIN-)
+ */
+static const int mcp3564_burnout_avail[][2] = {
+ [MCP3564_CONFIG0_CS_SEL_0_0_uA] = {0, 0},
+ [MCP3564_CONFIG0_CS_SEL_0_9_uA] = {0, 900},
+ [MCP3564_CONFIG0_CS_SEL_3_7_uA] = {0, 3700},
+ [MCP3564_CONFIG0_CS_SEL_15_uA] = {0, 15000}
+};
+
+/*
+ * BOOST[1:0]: ADC Bias Current Selection
+ */
+static const char * const mcp3564_boost_current_avail[] = {
+ [MCP3564_BOOST_CURRENT_x0_50] = "0.5",
+ [MCP3564_BOOST_CURRENT_x0_66] = "0.66",
+ [MCP3564_BOOST_CURRENT_x1_00] = "1",
+ [MCP3564_BOOST_CURRENT_x2_00] = "2",
+};
+
+/*
+ * Calibration bias values
+ */
+static const int mcp3564_calib_bias[] = {
+ -8388608, /* min: -2^23 */
+ 1, /* step: 1 */
+ 8388607 /* max: 2^23 - 1 */
+};
+
+/*
+ * Calibration scale values
+ * The Gain Error Calibration register (GAINCAL) is an
+ * unsigned 24-bit register that holds the digital gain error
+ * calibration value, GAINCAL which could be calculated by
+ * GAINCAL (V/V) = (GAINCAL[23:0])/8388608
+ * The gain error calibration value range in equivalent voltage is [0; 2-2^(-23)]
+ */
+static const unsigned int mcp3564_calib_scale[] = {
+ 0, /* min: 0 */
+ 1, /* step: 1/8388608 */
+ 16777215 /* max: 2 - 2^(-23) */
+};
+
+/* Programmable hardware gain x1/3, x1, x2, x4, x8, x16, x32, x64 */
+static const int mcp3564_hwgain_frac[] = {
+ 3, 10,
+ 1, 1,
+ 2, 1,
+ 4, 1,
+ 8, 1,
+ 16, 1,
+ 32, 1,
+ 64, 1
+};
+
+static const char *mcp3564_channel_labels[2] = {
+ "burnout_current", "temperature",
+};
+
+/**
+ * struct mcp3564_chip_info - chip specific data
+ * @name: device name
+ * @num_channels: number of channels
+ * @resolution: ADC resolution
+ * @has_vref: does the hardware has an internal voltage reference?
+ */
+struct mcp3564_chip_info {
+ const char *name;
+ unsigned int num_channels;
+ unsigned int resolution;
+ bool has_vref;
+};
+
+/**
+ * struct mcp3564_state - working data for a ADC device
+ * @chip_info: chip specific data
+ * @spi: SPI device structure
+ * @vref: the regulator device used as a voltage reference in case
+ * external voltage reference is used
+ * @vref_mv: voltage reference value in miliVolts
+ * @lock: synchronize access to driver's state members
+ * @dev_addr: hardware device address
+ * @oversampling: the index inside oversampling list of the ADC
+ * @hwgain: the index inside hardware gain list of the ADC
+ * @scale_tbls: table with precalculated scale
+ * @calib_bias: calibration bias value
+ * @calib_scale: calibration scale value
+ * @current_boost_mode: the index inside current boost list of the ADC
+ * @burnout_mode: the index inside current bias list of the ADC
+ * @auto_zeroing_mux: set if ADC auto-zeroing algorithm is enabled
+ * @auto_zeroing_ref: set if ADC auto-Zeroing Reference Buffer Setting is enabled
+ * @has_vref: does the ADC has an internal voltage reference?
+ * @labels: table with channels labels
+ */
+struct mcp3564_state {
+ const struct mcp3564_chip_info *chip_info;
+ struct spi_device *spi;
+ struct regulator *vref;
+ unsigned short vref_mv;
+ struct mutex lock; /* Synchronize access to driver's state members */
+ u8 dev_addr;
+ enum mcp3564_oversampling oversampling;
+ unsigned int hwgain;
+ unsigned int scale_tbls[MCP3564_MAX_PGA][2];
+ int calib_bias;
+ int calib_scale;
+ unsigned int current_boost_mode;
+ enum mcp3564_burnout burnout_mode;
+ bool auto_zeroing_mux;
+ bool auto_zeroing_ref;
+ bool has_vref;
+ const char *labels[MCP3564_MAX_CHANNELS];
+};
+
+static inline u8 mcp3564_cmd_write(u8 chip_addr, u8 reg)
+{
+ return MCP3564_CMD_HW_ADDR_SET(chip_addr) | MCP3564_CMD_ADDR_SET(reg) | BIT(1);
+}
+
+static inline u8 mcp3564_cmd_read(u8 chip_addr, u8 reg)
+{
+ return MCP3564_CMD_HW_ADDR_SET(chip_addr) | MCP3564_CMD_ADDR_SET(reg) | BIT(0);
+}
+
+static int mcp3564_read_8bits(struct mcp3564_state *adc, u8 reg, u8 *val)
+{
+ int ret;
+ u8 tx_buf;
+ u8 rx_buf;
+
+ tx_buf = mcp3564_cmd_read(adc->dev_addr, reg);
+
+ ret = spi_write_then_read(adc->spi, &tx_buf, sizeof(tx_buf),
+ &rx_buf, sizeof(rx_buf));
+ *val = rx_buf;
+
+ return ret;
+}
+
+static int mcp3564_read_16bits(struct mcp3564_state *adc, u8 reg, u16 *val)
+{
+ int ret;
+ u8 tx_buf;
+ __be16 rx_buf;
+
+ tx_buf = mcp3564_cmd_read(adc->dev_addr, reg);
+
+ ret = spi_write_then_read(adc->spi, &tx_buf, sizeof(tx_buf),
+ &rx_buf, sizeof(rx_buf));
+ *val = be16_to_cpu(rx_buf);
+
+ return ret;
+}
+
+static int mcp3564_read_32bits(struct mcp3564_state *adc, u8 reg, u32 *val)
+{
+ int ret;
+ u8 tx_buf;
+ __be32 rx_buf;
+
+ tx_buf = mcp3564_cmd_read(adc->dev_addr, reg);
+
+ ret = spi_write_then_read(adc->spi, &tx_buf, sizeof(tx_buf),
+ &rx_buf, sizeof(rx_buf));
+ *val = be32_to_cpu(rx_buf);
+
+ return ret;
+}
+
+static int mcp3564_write_8bits(struct mcp3564_state *adc, u8 reg, u8 val)
+{
+ u8 tmp;
+ u8 tx_buf[2];
+
+ tx_buf[0] = mcp3564_cmd_write(adc->dev_addr, reg);
+ tx_buf[1] = val;
+
+ return spi_write_then_read(adc->spi, tx_buf, sizeof(tx_buf), &tmp, 0);
+}
+
+static int mcp3564_write_24bits(struct mcp3564_state *adc, u8 reg, u32 val)
+{
+ u8 tmp;
+ __be32 val_be;
+
+ val |= (mcp3564_cmd_write(adc->dev_addr, reg) << 24);
+ val_be = cpu_to_be32(val);
+
+ return spi_write_then_read(adc->spi, &val_be, sizeof(val_be), &tmp, 0);
+}
+
+static int mcp3564_fast_cmd(struct mcp3564_state *adc, u8 fast_cmd)
+{
+ u8 val;
+ u8 tmp;
+
+ val = MCP3564_CMD_HW_ADDR_SET(adc->dev_addr) | MCP3564_CMD_ADDR_SET(fast_cmd);
+
+ return spi_write_then_read(adc->spi, &val, 1, &tmp, 0);
+}
+
+static int mcp3564_update_8bits(struct mcp3564_state *adc, u8 reg, u32 mask, u8 val)
+{
+ u8 tmp;
+ int ret;
+
+ ret = mcp3564_read_8bits(adc, reg, &tmp);
+ if (ret < 0)
+ return ret;
+
+ val &= mask;
+ val |= tmp & ~mask;
+ ret = mcp3564_write_8bits(adc, reg, val);
+
+ return ret;
+}
+
+static int mcp3564_set_current_boost_mode(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan,
+ unsigned int mode)
+{
+ struct mcp3564_state *adc = iio_priv(indio_dev);
+ int ret;
+
+ dev_dbg(&indio_dev->dev, "%s: %d\n", __func__, mode);
+
+ mutex_lock(&adc->lock);
+ ret = mcp3564_update_8bits(adc, MCP3564_CONFIG2_REG, MCP3564_CONFIG2_BOOST_CURRENT_MASK,
+ MCP3564_CONFIG2_BOOST_CURRENT_SET(mode));
+
+ if (ret)
+ dev_err(&indio_dev->dev, "Failed to configure CONFIG2 register\n");
+ else
+ adc->current_boost_mode = mode;
+
+ mutex_unlock(&adc->lock);
+
+ return ret;
+}
+
+static int mcp3564_get_current_boost_mode(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan)
+{
+ struct mcp3564_state *adc = iio_priv(indio_dev);
+
+ return adc->current_boost_mode;
+}
+
+static const struct iio_enum mcp3564_current_boost_mode_enum = {
+ .items = mcp3564_boost_current_avail,
+ .num_items = ARRAY_SIZE(mcp3564_boost_current_avail),
+ .set = mcp3564_set_current_boost_mode,
+ .get = mcp3564_get_current_boost_mode,
+};
+
+static const struct iio_chan_spec_ext_info mcp3564_ext_info[] = {
+ IIO_ENUM("boost_current_gain", IIO_SHARED_BY_ALL, &mcp3564_current_boost_mode_enum),
+ {
+ .name = "boost_current_gain_available",
+ .shared = IIO_SHARED_BY_ALL,
+ .read = iio_enum_available_read,
+ .private = (uintptr_t)&mcp3564_current_boost_mode_enum,
+ },
+ { }
+};
+
+static ssize_t mcp3564_auto_zeroing_mux_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+ struct mcp3564_state *adc = iio_priv(indio_dev);
+
+ return sysfs_emit(buf, "%d\n", adc->auto_zeroing_mux);
+}
+
+static ssize_t mcp3564_auto_zeroing_mux_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t len)
+{
+ struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+ struct mcp3564_state *adc = iio_priv(indio_dev);
+ bool auto_zero;
+ int ret;
+
+ ret = kstrtobool(buf, &auto_zero);
+ if (ret)
+ return ret;
+
+ mutex_lock(&adc->lock);
+ ret = mcp3564_update_8bits(adc, MCP3564_CONFIG2_REG, MCP3564_CONFIG2_AZ_MUX_MASK,
+ MCP3564_CONFIG2_AZ_MUX_SET(auto_zero));
+
+ if (ret)
+ dev_err(&indio_dev->dev, "Failed to update CONFIG2 register\n");
+ else
+ adc->auto_zeroing_mux = auto_zero;
+
+ mutex_unlock(&adc->lock);
+
+ return ret ? ret : len;
+}
+
+static ssize_t mcp3564_auto_zeroing_ref_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+ struct mcp3564_state *adc = iio_priv(indio_dev);
+
+ return sysfs_emit(buf, "%d\n", adc->auto_zeroing_ref);
+}
+
+static ssize_t mcp3564_auto_zeroing_ref_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t len)
+{
+ struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+ struct mcp3564_state *adc = iio_priv(indio_dev);
+ bool auto_zero;
+ int ret;
+
+ ret = kstrtobool(buf, &auto_zero);
+ if (ret)
+ return ret;
+
+ mutex_lock(&adc->lock);
+ ret = mcp3564_update_8bits(adc, MCP3564_CONFIG2_REG, MCP3564_CONFIG2_AZ_REF_MASK,
+ MCP3564_CONFIG2_AZ_REF_SET(auto_zero));
+
+ if (ret)
+ dev_err(&indio_dev->dev, "Failed to update CONFIG2 register\n");
+ else
+ adc->auto_zeroing_ref = auto_zero;
+
+ mutex_unlock(&adc->lock);
+
+ return ret ? ret : len;
+}
+
+static const struct iio_chan_spec mcp3564_channel_template = {
+ .type = IIO_VOLTAGE,
+ .indexed = 1,
+ .differential = 1,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+ .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SCALE) |
+ BIT(IIO_CHAN_INFO_CALIBSCALE) |
+ BIT(IIO_CHAN_INFO_CALIBBIAS) |
+ BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
+ .info_mask_shared_by_all_available = BIT(IIO_CHAN_INFO_SCALE) |
+ BIT(IIO_CHAN_INFO_CALIBSCALE) |
+ BIT(IIO_CHAN_INFO_CALIBBIAS) |
+ BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
+ .ext_info = mcp3564_ext_info,
+};
+
+static const struct iio_chan_spec mcp3564_temp_channel_template = {
+ .type = IIO_TEMP,
+ .channel = 0,
+ .address = ((MCP3564_TEMP_DIODE_P << 4) | MCP3564_TEMP_DIODE_M),
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+ .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SCALE) |
+ BIT(IIO_CHAN_INFO_CALIBSCALE) |
+ BIT(IIO_CHAN_INFO_CALIBBIAS) |
+ BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
+ .info_mask_shared_by_all_available = BIT(IIO_CHAN_INFO_SCALE) |
+ BIT(IIO_CHAN_INFO_CALIBSCALE) |
+ BIT(IIO_CHAN_INFO_CALIBBIAS) |
+ BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
+};
+
+static const struct iio_chan_spec mcp3564_burnout_channel_template = {
+ .type = IIO_CURRENT,
+ .output = true,
+ .channel = 0,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+ .info_mask_separate_available = BIT(IIO_CHAN_INFO_RAW),
+};
+
+/*
+ * Number of channels could be calculated:
+ * num_channels = single_ended_input + differential_input + temperature + burnout
+ * Eg. for MCP3561 (only 2 channels available: CH0 and CH1)
+ * single_ended_input = (CH0 - GND), (CH1 - GND) = 2
+ * differential_input = (CH0 - CH1), (CH0 - CH0) = 2
+ * num_channels = 2 + 2 + 2
+ * Generic formula is:
+ * num_channels = P^R(Number_of_single_ended_channels, 2) + 2 (temperature + burnout channels)
+ * P^R(Number_of_single_ended_channels, 2) is Permutations with Replacement of
+ * Number_of_single_ended_channels taken by 2
+ */
+static const struct mcp3564_chip_info mcp3564_chip_infos_tbl[] = {
+ [mcp3461] = {
+ .name = "mcp3461",
+ .num_channels = 6,
+ .resolution = 16,
+ .has_vref = false,
+ },
+ [mcp3462] = {
+ .name = "mcp3462",
+ .num_channels = 18,
+ .resolution = 16,
+ .has_vref = false,
+ },
+ [mcp3464] = {
+ .name = "mcp3464",
+ .num_channels = 66,
+ .resolution = 16,
+ .has_vref = false,
+ },
+ [mcp3561] = {
+ .name = "mcp3561",
+ .num_channels = 6,
+ .resolution = 24,
+ .has_vref = false,
+ },
+ [mcp3562] = {
+ .name = "mcp3562",
+ .num_channels = 18,
+ .resolution = 24,
+ .has_vref = false,
+ },
+ [mcp3564] = {
+ .name = "mcp3564",
+ .num_channels = 66,
+ .resolution = 24,
+ .has_vref = false,
+ },
+ [mcp3461r] = {
+ .name = "mcp3461r",
+ .num_channels = 6,
+ .resolution = 16,
+ .has_vref = false,
+ },
+ [mcp3462r] = {
+ .name = "mcp3462r",
+ .num_channels = 18,
+ .resolution = 16,
+ .has_vref = true,
+ },
+ [mcp3464r] = {
+ .name = "mcp3464r",
+ .num_channels = 66,
+ .resolution = 16,
+ .has_vref = true,
+ },
+ [mcp3561r] = {
+ .name = "mcp3561r",
+ .num_channels = 6,
+ .resolution = 24,
+ .has_vref = true,
+ },
+ [mcp3562r] = {
+ .name = "mcp3562r",
+ .num_channels = 18,
+ .resolution = 24,
+ .has_vref = true,
+ },
+ [mcp3564r] = {
+ .name = "mcp3564r",
+ .num_channels = 66,
+ .resolution = 24,
+ .has_vref = true,
+ },
+};
+
+static int mcp3564_read_single_value(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *channel,
+ int *val)
+{
+ struct mcp3564_state *adc = iio_priv(indio_dev);
+ int ret;
+ u8 tmp;
+ int ret_read = 0;
+
+ ret = mcp3564_write_8bits(adc, MCP3564_MUX_REG, channel->address);
+ if (ret)
+ return ret;
+
+ /* Start ADC Conversion using fast command (overwrites ADC_MODE[1:0] = 11) */
+ ret = mcp3564_fast_cmd(adc, MCP3564_FASTCMD_START);
+ if (ret)
+ return ret;
+
+ /*
+ * Check if the conversion is ready. If not, wait a little bit, and
+ * in case of timeout exit with an error.
+ */
+ ret = read_poll_timeout(mcp3564_read_8bits, ret_read,
+ ret_read || !(tmp & MCP3564_DATA_READY_MASK),
+ 20000, MCP3564_DATA_READY_TIMEOUT_MS * 1000, true,
+ adc, MCP3564_IRQ_REG, &tmp);
+
+ /* failed to read status register */
+ if (ret_read)
+ return ret_read;
+
+ if (ret)
+ return ret;
+
+ if (tmp & MCP3564_DATA_READY_MASK)
+ /* failing to finish conversion */
+ return -EBUSY;
+
+ return mcp3564_read_32bits(adc, MCP3564_ADCDATA_REG, val);
+}
+
+static int mcp3564_read_avail(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *channel,
+ const int **vals, int *type,
+ int *length, long mask)
+{
+ struct mcp3564_state *adc = iio_priv(indio_dev);
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ if (!channel->output)
+ return -EINVAL;
+
+ *vals = mcp3564_burnout_avail[0];
+ *length = ARRAY_SIZE(mcp3564_burnout_avail) * 2;
+ *type = IIO_VAL_INT_PLUS_MICRO;
+ return IIO_AVAIL_LIST;
+ case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+ *vals = mcp3564_oversampling_avail;
+ *length = ARRAY_SIZE(mcp3564_oversampling_avail);
+ *type = IIO_VAL_INT;
+ return IIO_AVAIL_LIST;
+ case IIO_CHAN_INFO_SCALE:
+ *vals = (int *)adc->scale_tbls;
+ *length = ARRAY_SIZE(adc->scale_tbls) * 2;
+ *type = IIO_VAL_INT_PLUS_NANO;
+ return IIO_AVAIL_LIST;
+ case IIO_CHAN_INFO_CALIBBIAS:
+ *vals = mcp3564_calib_bias;
+ *type = IIO_VAL_INT;
+ return IIO_AVAIL_RANGE;
+ case IIO_CHAN_INFO_CALIBSCALE:
+ *vals = mcp3564_calib_scale;
+ *type = IIO_VAL_INT;
+ return IIO_AVAIL_RANGE;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int mcp3564_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *channel,
+ int *val, int *val2, long mask)
+{
+ struct mcp3564_state *adc = iio_priv(indio_dev);
+ int ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ if (channel->output) {
+ mutex_lock(&adc->lock);
+ *val = mcp3564_burnout_avail[adc->burnout_mode][0];
+ *val2 = mcp3564_burnout_avail[adc->burnout_mode][1];
+ mutex_unlock(&adc->lock);
+ return IIO_VAL_INT_PLUS_MICRO;
+ }
+
+ ret = mcp3564_read_single_value(indio_dev, channel, val);
+ if (ret)
+ return -EINVAL;
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_SCALE:
+ mutex_lock(&adc->lock);
+ *val = adc->scale_tbls[adc->hwgain][0];
+ *val2 = adc->scale_tbls[adc->hwgain][1];
+ mutex_unlock(&adc->lock);
+ return IIO_VAL_INT_PLUS_NANO;
+ case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+ *val = mcp3564_oversampling_avail[adc->oversampling];
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_CALIBBIAS:
+ *val = adc->calib_bias;
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_CALIBSCALE:
+ *val = adc->calib_scale;
+ return IIO_VAL_INT;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int mcp3564_write_raw_get_fmt(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ long info)
+{
+ switch (info) {
+ case IIO_CHAN_INFO_RAW:
+ return IIO_VAL_INT_PLUS_MICRO;
+ case IIO_CHAN_INFO_CALIBBIAS:
+ case IIO_CHAN_INFO_CALIBSCALE:
+ case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_SCALE:
+ return IIO_VAL_INT_PLUS_NANO;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int mcp3564_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *channel, int val,
+ int val2, long mask)
+{
+ struct mcp3564_state *adc = iio_priv(indio_dev);
+ int tmp;
+ unsigned int hwgain;
+ enum mcp3564_burnout burnout;
+ int ret = 0;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ if (!channel->output)
+ return -EINVAL;
+
+ for (burnout = 0; burnout < MCP3564_MAX_BURNOUT_IDX; burnout++) {
+ if (val == mcp3564_burnout_avail[burnout][0] &&
+ val2 == mcp3564_burnout_avail[burnout][1])
+ break;
+ }
+
+ if (burnout == MCP3564_MAX_BURNOUT_IDX)
+ return -EINVAL;
+
+ if (burnout == adc->burnout_mode)
+ return ret;
+
+ mutex_lock(&adc->lock);
+ ret = mcp3564_update_8bits(adc, MCP3564_CONFIG0_REG,
+ MCP3564_CONFIG0_CS_SEL_MASK,
+ MCP3564_CONFIG0_CS_SEL_SET(burnout));
+
+ if (ret)
+ dev_err(&indio_dev->dev, "Failed to configure burnout current\n");
+ else
+ adc->burnout_mode = burnout;
+ mutex_unlock(&adc->lock);
+ return ret;
+ case IIO_CHAN_INFO_CALIBBIAS:
+ if (val < mcp3564_calib_bias[0] && val > mcp3564_calib_bias[2])
+ return -EINVAL;
+
+ mutex_lock(&adc->lock);
+ ret = mcp3564_write_24bits(adc, MCP3564_OFFSETCAL_REG, val);
+ if (!ret)
+ adc->calib_bias = val;
+ mutex_unlock(&adc->lock);
+ return ret;
+ case IIO_CHAN_INFO_CALIBSCALE:
+ if (val < mcp3564_calib_scale[0] && val > mcp3564_calib_scale[2])
+ return -EINVAL;
+
+ if (adc->calib_scale == val)
+ return ret;
+
+ mutex_lock(&adc->lock);
+ ret = mcp3564_write_24bits(adc, MCP3564_GAINCAL_REG, val);
+ if (!ret)
+ adc->calib_scale = val;
+ mutex_unlock(&adc->lock);
+ return ret;
+ case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+ if (val < 0)
+ return -EINVAL;
+
+ tmp = find_closest(val, mcp3564_oversampling_avail,
+ ARRAY_SIZE(mcp3564_oversampling_avail));
+
+ if (adc->oversampling == tmp)
+ return ret;
+
+ mutex_lock(&adc->lock);
+ ret = mcp3564_update_8bits(adc, MCP3564_CONFIG1_REG,
+ MCP3564_CONFIG1_OVERSPL_RATIO_MASK,
+ MCP3564_CONFIG1_OVERSPL_RATIO_SET(adc->oversampling));
+ if (!ret)
+ adc->oversampling = tmp;
+ mutex_unlock(&adc->lock);
+ return ret;
+ case IIO_CHAN_INFO_SCALE:
+ for (hwgain = 0; hwgain < MCP3564_MAX_PGA; hwgain++) {
+ if (val == adc->scale_tbls[hwgain][0] &&
+ val2 == adc->scale_tbls[hwgain][1])
+ break;
+ }
+
+ if (hwgain == MCP3564_MAX_PGA)
+ return -EINVAL;
+
+ if (hwgain == adc->hwgain)
+ return ret;
+
+ mutex_lock(&adc->lock);
+ /* Update GAIN in CONFIG2[5:3] -> GAIN[2:0]*/
+ ret = mcp3564_update_8bits(adc, MCP3564_CONFIG2_REG,
+ MCP3564_CONFIG2_HARDWARE_GAIN_MASK,
+ MCP3564_CONFIG2_HARDWARE_GAIN_SET(hwgain));
+ if (!ret)
+ adc->hwgain = hwgain;
+
+ mutex_unlock(&adc->lock);
+ return ret;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int mcp3564_read_label(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, char *label)
+{
+ struct mcp3564_state *adc = iio_priv(indio_dev);
+
+ return sprintf(label, "%s\n", adc->labels[chan->scan_index]);
+}
+
+static int mcp3564_parse_fw_children(struct iio_dev *indio_dev)
+{
+ struct mcp3564_state *adc = iio_priv(indio_dev);
+ struct device *dev = &adc->spi->dev;
+ struct iio_chan_spec *channels;
+ struct fwnode_handle *child;
+ struct iio_chan_spec chanspec = mcp3564_channel_template;
+ struct iio_chan_spec temp_chanspec = mcp3564_temp_channel_template;
+ struct iio_chan_spec burnout_chanspec = mcp3564_burnout_channel_template;
+ int chan_idx = 0;
+ unsigned int num_ch;
+ u32 inputs[2];
+ const char *node_name;
+ const char *label;
+ int ret;
+
+ num_ch = device_get_child_node_count(dev);
+ if (num_ch == 0)
+ return dev_err_probe(&indio_dev->dev, -ENODEV,
+ "FW has no channels defined\n");
+
+ /* Reserve space for burnout and temperature channel */
+ num_ch += 2;
+
+ if (num_ch > adc->chip_info->num_channels) {
+ return dev_err_probe(dev, -EINVAL, "Too many channels %d > %d\n",
+ num_ch, adc->chip_info->num_channels);
+ }
+
+ channels = devm_kcalloc(dev, num_ch, sizeof(*channels), GFP_KERNEL);
+ if (!channels)
+ return dev_err_probe(dev, -ENOMEM, "Can't allocate memory\n");
+
+ device_for_each_child_node(dev, child) {
+ node_name = fwnode_get_name(child);
+
+ if (fwnode_property_present(child, "diff-channels")) {
+ ret = fwnode_property_read_u32_array(child,
+ "diff-channels",
+ inputs,
+ ARRAY_SIZE(inputs));
+ chanspec.differential = 1;
+ } else {
+ ret = fwnode_property_read_u32(child, "reg", &inputs[0]);
+
+ chanspec.differential = 0;
+ inputs[1] = MCP3564_AGND;
+ }
+ if (ret) {
+ fwnode_handle_put(child);
+ return ret;
+ }
+
+ if (inputs[0] > MCP3564_INTERNAL_VCM ||
+ inputs[1] > MCP3564_INTERNAL_VCM) {
+ fwnode_handle_put(child);
+ return dev_err_probe(&indio_dev->dev, -EINVAL,
+ "Channel index > %d, for %s\n",
+ MCP3564_INTERNAL_VCM + 1,
+ node_name);
+ }
+
+ chanspec.address = (inputs[0] << 4) | inputs[1];
+ chanspec.channel = inputs[0];
+ chanspec.channel2 = inputs[1];
+ chanspec.scan_index = chan_idx;
+
+ if (fwnode_property_present(child, "label")) {
+ fwnode_property_read_string(child, "label", &label);
+ adc->labels[chan_idx] = label;
+ }
+
+ channels[chan_idx] = chanspec;
+ chan_idx++;
+ }
+
+ /* Add burnout current channel */
+ burnout_chanspec.scan_index = chan_idx;
+ channels[chan_idx] = burnout_chanspec;
+ adc->labels[chan_idx] = mcp3564_channel_labels[0];
+ chanspec.scan_index = chan_idx;
+ chan_idx++;
+
+ /* Add temperature channel */
+ temp_chanspec.scan_index = chan_idx;
+ channels[chan_idx] = temp_chanspec;
+ adc->labels[chan_idx] = mcp3564_channel_labels[1];
+ chan_idx++;
+
+ indio_dev->num_channels = chan_idx;
+ indio_dev->channels = channels;
+
+ return 0;
+}
+
+static void mcp3564_disable_reg(void *reg)
+{
+ regulator_disable(reg);
+}
+
+static void mcp3564_fill_scale_tbls(struct mcp3564_state *adc)
+{
+ unsigned int pow = adc->chip_info->resolution - 1;
+ int ref;
+ unsigned int i;
+ int tmp0;
+ u64 tmp1;
+
+ for (i = 0; i < MCP3564_MAX_PGA; i++) {
+ ref = adc->vref_mv;
+ tmp1 = shift_right((u64)ref * NANO, pow);
+ div_u64_rem(tmp1, NANO, &tmp0);
+
+ tmp1 = tmp1 * mcp3564_hwgain_frac[(2 * i) + 1];
+ tmp0 = (int)div_u64(tmp1, mcp3564_hwgain_frac[2 * i]);
+
+ adc->scale_tbls[i][1] = tmp0;
+ }
+}
+
+static int mcp3564_config(struct iio_dev *indio_dev)
+{
+ struct mcp3564_state *adc = iio_priv(indio_dev);
+ struct device *dev = &adc->spi->dev;
+ const struct spi_device_id *dev_id;
+ u8 tmp_reg;
+ u16 tmp_u16;
+ enum mcp3564_ids ids;
+ int ret = 0;
+ unsigned int tmp = 0x01;
+ bool err = true;
+
+ /*
+ * The address is set on a per-device basis by fuses in the factory,
+ * configured on request. If not requested, the fuses are set for 0x1.
+ * The device address is part of the device markings to avoid
+ * potential confusion. This address is coded on two bits, so four possible
+ * addresses are available when multiple devices are present on the same
+ * SPI bus with only one Chip Select line for all devices.
+ */
+ device_property_read_u32(dev, "microchip,hw-device-address", &tmp);
+
+ if (tmp > 3) {
+ dev_err_probe(dev, tmp,
+ "invalid device address. Must be in range 0-3.\n");
+ return -EINVAL;
+ }
+
+ adc->dev_addr = MCP3564_HW_ADDR_MASK & tmp;
+
+ dev_dbg(dev, "use device address %i\n", adc->dev_addr);
+
+ ret = mcp3564_read_8bits(adc, MCP3564_RESERVED_C_REG, &tmp_reg);
+ if (ret < 0)
+ return ret;
+
+ switch (tmp_reg) {
+ case MCP3564_C_REG_DEFAULT:
+ adc->has_vref = false;
+ break;
+ case MCP3564R_C_REG_DEFAULT:
+ adc->has_vref = true;
+ break;
+ default:
+ dev_info(dev, "Unknown chip found: %d\n", tmp_reg);
+ err = true;
+ }
+
+ if (!err) {
+ ret = mcp3564_read_16bits(adc, MCP3564_RESERVED_E_REG, &tmp_u16);
+ if (ret < 0)
+ return ret;
+
+ switch (tmp_u16 & MCP3564_HW_ID_MASK) {
+ case MCP3461_HW_ID:
+ if (adc->has_vref)
+ ids = mcp3461r;
+ else
+ ids = mcp3461;
+ break;
+ case MCP3462_HW_ID:
+ if (adc->has_vref)
+ ids = mcp3462r;
+ else
+ ids = mcp3462;
+ break;
+ case MCP3464_HW_ID:
+ if (adc->has_vref)
+ ids = mcp3464r;
+ else
+ ids = mcp3464;
+ break;
+ case MCP3561_HW_ID:
+ if (adc->has_vref)
+ ids = mcp3561r;
+ else
+ ids = mcp3561;
+ break;
+ case MCP3562_HW_ID:
+ if (adc->has_vref)
+ ids = mcp3562r;
+ else
+ ids = mcp3562;
+ break;
+ case MCP3564_HW_ID:
+ if (adc->has_vref)
+ ids = mcp3564r;
+ else
+ ids = mcp3564;
+ break;
+ default:
+ dev_info(dev, "Unknown chip found: %d\n", tmp_u16);
+ err = true;
+ }
+ }
+
+ if (err) {
+ /*
+ * If failed to identify the hardware based on internal registers,
+ * try using fallback compatible in device tree to deal with some newer part number.
+ */
+ adc->chip_info = spi_get_device_match_data(adc->spi);
+ if (!adc->chip_info) {
+ dev_id = spi_get_device_id(adc->spi);
+ adc->chip_info = (const struct mcp3564_chip_info *)dev_id->driver_data;
+ }
+
+ adc->has_vref = adc->chip_info->has_vref;
+ } else {
+ adc->chip_info = &mcp3564_chip_infos_tbl[ids];
+ }
+
+ dev_dbg(dev, "Found %s chip\n", adc->chip_info->name);
+
+ adc->vref = devm_regulator_get_optional(dev, "vref");
+ if (IS_ERR(adc->vref)) {
+ if (IS_ERR(adc->vref)) {
+ /* Check if chip has internal vref */
+ if (!adc->has_vref)
+ return dev_err_probe(dev, PTR_ERR(adc->vref),
+ "Unknown Vref\n");
+ adc->vref = NULL;
+ dev_dbg(dev, "%s: Using internal Vref\n", __func__);
+ } else {
+ return dev_err_probe(dev, PTR_ERR(adc->vref),
+ "failed to get regulator\n");
+ }
+ } else {
+ ret = regulator_enable(adc->vref);
+ if (ret)
+ return ret;
+
+ ret = devm_add_action_or_reset(dev, mcp3564_disable_reg,
+ adc->vref);
+ if (ret)
+ return ret;
+
+ dev_dbg(dev, "%s: Using External Vref\n", __func__);
+
+ ret = regulator_get_voltage(adc->vref);
+ if (ret < 0) {
+ return dev_err_probe(dev, ret,
+ "Failed to read vref regulator\n");
+ }
+
+ adc->vref_mv = ret / MILLI;
+ }
+
+ ret = mcp3564_parse_fw_children(indio_dev);
+ if (ret)
+ return ret;
+
+ /*
+ * Command sequence that ensures a recovery with the desired settings
+ * in any cases of loss-of-power scenario (Full Chip Reset):
+ * - Write LOCK register to 0xA5
+ * - Write IRQ register to 0x03
+ * - Send "Device Full Reset" fast command
+ * - Wait 1ms for "Full Reset" to complete
+ */
+ ret = mcp3564_write_8bits(adc, MCP3564_LOCK_REG, MCP3564_LOCK_WRITE_ACCESS_PASSWORD);
+ if (ret)
+ return ret;
+
+ ret = mcp3564_write_8bits(adc, MCP3564_IRQ_REG, 0x03);
+ if (ret)
+ return ret;
+
+ ret = mcp3564_fast_cmd(adc, MCP3564_FASTCMD_RESET);
+ if (ret)
+ return ret;
+
+ mdelay(1);
+
+ /* set a gain of 1x for GAINCAL */
+ ret = mcp3564_write_24bits(adc, MCP3564_GAINCAL_REG, MCP3564_DEFAULT_GAINCAL);
+ if (ret)
+ return ret;
+
+ adc->calib_scale = MCP3564_DEFAULT_GAINCAL;
+
+ ret = mcp3564_write_24bits(adc, MCP3564_OFFSETCAL_REG, MCP3564_DEFAULT_OFFSETCAL);
+ if (ret)
+ return ret;
+
+ ret = mcp3564_write_24bits(adc, MCP3564_TIMER_REG, MCP3564_TIMER_DEFAULT_VALUE);
+ if (ret)
+ return ret;
+
+ ret = mcp3564_write_24bits(adc, MCP3564_SCAN_REG,
+ MCP3564_SCAN_DELAY_TIME_SET(MCP3564_NO_DELAY) |
+ MCP3564_SCAN_CH_SEL_SET(MCP3564_SCAN_DEFAULT_VALUE));
+ if (ret)
+ return ret;
+
+ ret = mcp3564_write_8bits(adc, MCP3564_MUX_REG, MCP3564_MUX_SET(MCP3564_CH0, MCP3564_CH1));
+ if (ret)
+ return ret;
+
+ ret = mcp3564_write_8bits(adc, MCP3564_IRQ_REG,
+ FIELD_PREP(MCP3464_EN_FASTCMD_MASK, 1) |
+ FIELD_PREP(MCP3464_EN_STP_MASK, 1));
+ if (ret)
+ return ret;
+
+ tmp_reg = MCP3564_CONFIG3_CONV_MODE_SET(MCP3464_CONFIG3_CONV_MODE_ONE_SHOT_STANDBY);
+ tmp_reg |= MCP3564_CONFIG3_DATA_FORMAT_SET(MCP3464_CONFIG3_DATA_FMT_32B_SGN_EXT);
+ tmp_reg |= MCP3464_CONFIG3_EN_OFFCAL_MASK;
+ tmp_reg |= MCP3464_CONFIG3_EN_GAINCAL_MASK;
+
+ ret = mcp3564_write_8bits(adc, MCP3564_CONFIG3_REG, tmp_reg);
+ if (ret)
+ return ret;
+
+ tmp_reg = MCP3564_CONFIG2_BOOST_CURRENT_SET(MCP3564_BOOST_CURRENT_x1_00);
+ tmp_reg |= MCP3564_CONFIG2_HARDWARE_GAIN_SET(0x01);
+ tmp_reg |= MCP3564_CONFIG2_AZ_MUX_SET(1);
+
+ ret = mcp3564_write_8bits(adc, MCP3564_CONFIG2_REG, tmp_reg);
+ if (ret)
+ return ret;
+
+ adc->hwgain = 0x01;
+ adc->auto_zeroing_mux = true;
+ adc->auto_zeroing_ref = false;
+ adc->current_boost_mode = MCP3564_BOOST_CURRENT_x1_00;
+
+ tmp_reg = MCP3564_CONFIG1_OVERSPL_RATIO_SET(MCP3564_OVERSAMPLING_RATIO_98304);
+
+ ret = mcp3564_write_8bits(adc, MCP3564_CONFIG1_REG, tmp_reg);
+ if (ret)
+ return ret;
+
+ adc->oversampling = MCP3564_OVERSAMPLING_RATIO_98304;
+
+ tmp_reg = MCP3564_CONFIG0_ADC_MODE_MASK_SET(MCP3564_ADC_MODE_STANDBY);
+ tmp_reg |= MCP3564_CONFIG0_CS_SEL_SET(MCP3564_CONFIG0_CS_SEL_0_0_uA);
+ tmp_reg |= MCP3564_CONFIG0_CLK_SEL_SET(MCP3564_CONFIG0_USE_INT_CLK);
+ tmp_reg |= MCP3456_CONFIG0_BIT6_DEFAULT;
+
+ if (!adc->vref) {
+ tmp_reg |= MCP3564_CONFIG0_VREF_SET(1);
+ adc->vref_mv = MCP3564R_INT_VREF_MV;
+ }
+
+ ret = mcp3564_write_8bits(adc, MCP3564_CONFIG0_REG, tmp_reg);
+
+ adc->burnout_mode = MCP3564_CONFIG0_CS_SEL_0_0_uA;
+
+ return ret;
+}
+
+static IIO_DEVICE_ATTR(auto_zeroing_ref_enable, 0644,
+ mcp3564_auto_zeroing_ref_show,
+ mcp3564_auto_zeroing_ref_store, 0);
+
+static IIO_DEVICE_ATTR(auto_zeroing_mux_enable, 0644,
+ mcp3564_auto_zeroing_mux_show,
+ mcp3564_auto_zeroing_mux_store, 0);
+
+//#define MCP3564_DEV_ATTR(name) (&iio_dev_attr_##name.dev_attr.attr)
+
+static struct attribute *mcp3564_attributes[] = {
+ &iio_dev_attr_auto_zeroing_mux_enable.dev_attr.attr,
+ NULL
+};
+
+static struct attribute *mcp3564r_attributes[] = {
+ &iio_dev_attr_auto_zeroing_mux_enable.dev_attr.attr,
+ &iio_dev_attr_auto_zeroing_ref_enable.dev_attr.attr,
+ NULL
+};
+
+static struct attribute_group mcp3564_attribute_group = {
+ .attrs = mcp3564_attributes,
+};
+
+static struct attribute_group mcp3564r_attribute_group = {
+ .attrs = mcp3564r_attributes,
+};
+
+static const struct iio_info mcp3564_info = {
+ .read_raw = mcp3564_read_raw,
+ .read_avail = mcp3564_read_avail,
+ .write_raw = mcp3564_write_raw,
+ .write_raw_get_fmt = mcp3564_write_raw_get_fmt,
+ .read_label = mcp3564_read_label,
+ .attrs = &mcp3564_attribute_group,
+};
+
+static const struct iio_info mcp3564r_info = {
+ .read_raw = mcp3564_read_raw,
+ .read_avail = mcp3564_read_avail,
+ .write_raw = mcp3564_write_raw,
+ .write_raw_get_fmt = mcp3564_write_raw_get_fmt,
+ .read_label = mcp3564_read_label,
+ .attrs = &mcp3564r_attribute_group,
+};
+
+static int mcp3564_probe(struct spi_device *spi)
+{
+ int ret;
+ struct iio_dev *indio_dev;
+ struct mcp3564_state *adc;
+
+ indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*adc));
+ if (!indio_dev) {
+ dev_err_probe(&indio_dev->dev, PTR_ERR(indio_dev),
+ "Can't allocate iio device\n");
+ return -ENOMEM;
+ }
+
+ adc = iio_priv(indio_dev);
+ adc->spi = spi;
+
+ dev_dbg(&spi->dev, "%s: probe(spi = 0x%p)\n", __func__, spi);
+
+ /*
+ * Do any chip specific initialization, e.g:
+ * read/write some registers
+ * enable/disable certain channels
+ * change the sampling rate to the requested value
+ */
+ ret = mcp3564_config(indio_dev);
+ if (ret) {
+ return dev_err_probe(&spi->dev, ret,
+ "Can't configure MCP356X device\n");
+ }
+
+ dev_dbg(&spi->dev, "%s: Vref (mV): %d\n", __func__, adc->vref_mv);
+
+ mcp3564_fill_scale_tbls(adc);
+
+ indio_dev->name = adc->chip_info->name;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+
+ if (!adc->vref)
+ indio_dev->info = &mcp3564r_info;
+ else
+ indio_dev->info = &mcp3564_info;
+
+ mutex_init(&adc->lock);
+
+ ret = devm_iio_device_register(&spi->dev, indio_dev);
+ if (ret) {
+ return dev_err_probe(&spi->dev, ret,
+ "Can't register IIO device\n");
+ }
+
+ return 0;
+}
+
+static const struct of_device_id mcp3564_dt_ids[] = {
+ { .compatible = "microchip,mcp3461", .data = &mcp3564_chip_infos_tbl[mcp3461] },
+ { .compatible = "microchip,mcp3462", .data = &mcp3564_chip_infos_tbl[mcp3462] },
+ { .compatible = "microchip,mcp3464", .data = &mcp3564_chip_infos_tbl[mcp3464] },
+ { .compatible = "microchip,mcp3561", .data = &mcp3564_chip_infos_tbl[mcp3561] },
+ { .compatible = "microchip,mcp3562", .data = &mcp3564_chip_infos_tbl[mcp3562] },
+ { .compatible = "microchip,mcp3564", .data = &mcp3564_chip_infos_tbl[mcp3564] },
+ { .compatible = "microchip,mcp3461r", .data = &mcp3564_chip_infos_tbl[mcp3461r] },
+ { .compatible = "microchip,mcp3462r", .data = &mcp3564_chip_infos_tbl[mcp3462r] },
+ { .compatible = "microchip,mcp3464r", .data = &mcp3564_chip_infos_tbl[mcp3464r] },
+ { .compatible = "microchip,mcp3561r", .data = &mcp3564_chip_infos_tbl[mcp3561r] },
+ { .compatible = "microchip,mcp3562r", .data = &mcp3564_chip_infos_tbl[mcp3562r] },
+ { .compatible = "microchip,mcp3564r", .data = &mcp3564_chip_infos_tbl[mcp3564r] },
+ { }
+};
+MODULE_DEVICE_TABLE(of, mcp3564_dt_ids);
+
+static const struct spi_device_id mcp3564_id[] = {
+ { "mcp3461", (kernel_ulong_t)&mcp3564_chip_infos_tbl[mcp3461] },
+ { "mcp3462", (kernel_ulong_t)&mcp3564_chip_infos_tbl[mcp3462] },
+ { "mcp3464", (kernel_ulong_t)&mcp3564_chip_infos_tbl[mcp3464] },
+ { "mcp3561", (kernel_ulong_t)&mcp3564_chip_infos_tbl[mcp3561] },
+ { "mcp3562", (kernel_ulong_t)&mcp3564_chip_infos_tbl[mcp3562] },
+ { "mcp3564", (kernel_ulong_t)&mcp3564_chip_infos_tbl[mcp3564] },
+ { "mcp3461r", (kernel_ulong_t)&mcp3564_chip_infos_tbl[mcp3461r] },
+ { "mcp3462r", (kernel_ulong_t)&mcp3564_chip_infos_tbl[mcp3462r] },
+ { "mcp3464r", (kernel_ulong_t)&mcp3564_chip_infos_tbl[mcp3464r] },
+ { "mcp3561r", (kernel_ulong_t)&mcp3564_chip_infos_tbl[mcp3561r] },
+ { "mcp3562r", (kernel_ulong_t)&mcp3564_chip_infos_tbl[mcp3562r] },
+ { "mcp3564r", (kernel_ulong_t)&mcp3564_chip_infos_tbl[mcp3564r] },
+ { }
+};
+MODULE_DEVICE_TABLE(spi, mcp3564_id);
+
+static struct spi_driver mcp3564_driver = {
+ .driver = {
+ .name = "mcp3564",
+ .of_match_table = mcp3564_dt_ids,
+ },
+ .probe = mcp3564_probe,
+ .id_table = mcp3564_id,
+};
+
+module_spi_driver(mcp3564_driver);
+
+MODULE_AUTHOR("Marius Cristea <marius.cristea@xxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("Microchip MCP346x/MCP346xR and MCP356x/MCP346xR ADCs");
+MODULE_LICENSE("GPL v2");
--
2.34.1