Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 934 insertions, 0 deletions

diff --git a/drivers/hwmon/pmbus/ltc2978.c b/drivers/hwmon/pmbus/ltc2978.c
new file mode 100644
index 000000000..6d2592731
--- /dev/null
+++ b/drivers/hwmon/pmbus/ltc2978.c
@@ -0,0 +1,934 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Hardware monitoring driver for LTC2978 and compatible chips.
+ *
+ * Copyright (c) 2011 Ericsson AB.
+ * Copyright (c) 2013, 2014, 2015 Guenter Roeck
+ * Copyright (c) 2015 Linear Technology
+ * Copyright (c) 2018 Analog Devices Inc.
+ */
+
+#include <linux/delay.h>
+#include <linux/jiffies.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/i2c.h>
+#include <linux/regulator/driver.h>
+#include "pmbus.h"
+
+enum chips {
+	/* Managers */
+	ltc2972, ltc2974, ltc2975, ltc2977, ltc2978, ltc2979, ltc2980,
+	/* Controllers */
+	ltc3880, ltc3882, ltc3883, ltc3884, ltc3886, ltc3887, ltc3889, ltc7880,
+	/* Modules */
+	ltm2987, ltm4664, ltm4675, ltm4676, ltm4677, ltm4678, ltm4680, ltm4686,
+	ltm4700,
+};
+
+/* Common for all chips */
+#define LTC2978_MFR_VOUT_PEAK		0xdd
+#define LTC2978_MFR_VIN_PEAK		0xde
+#define LTC2978_MFR_TEMPERATURE_PEAK	0xdf
+#define LTC2978_MFR_SPECIAL_ID		0xe7	/* Undocumented on LTC3882 */
+#define LTC2978_MFR_COMMON		0xef
+
+/* LTC2974, LTC2975, LCT2977, LTC2980, LTC2978, and LTM2987 */
+#define LTC2978_MFR_VOUT_MIN		0xfb
+#define LTC2978_MFR_VIN_MIN		0xfc
+#define LTC2978_MFR_TEMPERATURE_MIN	0xfd
+
+/* LTC2974, LTC2975 */
+#define LTC2974_MFR_IOUT_PEAK		0xd7
+#define LTC2974_MFR_IOUT_MIN		0xd8
+
+/* LTC3880, LTC3882, LTC3883, LTC3887, LTM4675, and LTM4676 */
+#define LTC3880_MFR_IOUT_PEAK		0xd7
+#define LTC3880_MFR_CLEAR_PEAKS		0xe3
+#define LTC3880_MFR_TEMPERATURE2_PEAK	0xf4
+
+/* LTC3883, LTC3884, LTC3886, LTC3889 and LTC7880 only */
+#define LTC3883_MFR_IIN_PEAK		0xe1
+
+
+/* LTC2975 only */
+#define LTC2975_MFR_IIN_PEAK		0xc4
+#define LTC2975_MFR_IIN_MIN		0xc5
+#define LTC2975_MFR_PIN_PEAK		0xc6
+#define LTC2975_MFR_PIN_MIN		0xc7
+
+#define LTC2978_ID_MASK			0xfff0
+
+#define LTC2972_ID			0x0310
+#define LTC2974_ID			0x0210
+#define LTC2975_ID			0x0220
+#define LTC2977_ID			0x0130
+#define LTC2978_ID_REV1			0x0110	/* Early revision */
+#define LTC2978_ID_REV2			0x0120
+#define LTC2979_ID_A			0x8060
+#define LTC2979_ID_B			0x8070
+#define LTC2980_ID_A			0x8030	/* A/B for two die IDs */
+#define LTC2980_ID_B			0x8040
+#define LTC3880_ID			0x4020
+#define LTC3882_ID			0x4200
+#define LTC3882_ID_D1			0x4240	/* Dash 1 */
+#define LTC3883_ID			0x4300
+#define LTC3884_ID			0x4C00
+#define LTC3886_ID			0x4600
+#define LTC3887_ID			0x4700
+#define LTM2987_ID_A			0x8010	/* A/B for two die IDs */
+#define LTM2987_ID_B			0x8020
+#define LTC3889_ID			0x4900
+#define LTC7880_ID			0x49E0
+#define LTM4664_ID			0x4120
+#define LTM4675_ID			0x47a0
+#define LTM4676_ID_REV1			0x4400
+#define LTM4676_ID_REV2			0x4480
+#define LTM4676A_ID			0x47e0
+#define LTM4677_ID_REV1			0x47B0
+#define LTM4677_ID_REV2			0x47D0
+#define LTM4678_ID_REV1			0x4100
+#define LTM4678_ID_REV2			0x4110
+#define LTM4680_ID			0x4140
+#define LTM4686_ID			0x4770
+#define LTM4700_ID			0x4130
+
+#define LTC2972_NUM_PAGES		2
+#define LTC2974_NUM_PAGES		4
+#define LTC2978_NUM_PAGES		8
+#define LTC3880_NUM_PAGES		2
+#define LTC3883_NUM_PAGES		1
+
+#define LTC_POLL_TIMEOUT		100	/* in milli-seconds */
+
+#define LTC_NOT_BUSY			BIT(6)
+#define LTC_NOT_PENDING			BIT(5)
+
+/*
+ * LTC2978 clears peak data whenever the CLEAR_FAULTS command is executed, which
+ * happens pretty much each time chip data is updated. Raw peak data therefore
+ * does not provide much value. To be able to provide useful peak data, keep an
+ * internal cache of measured peak data, which is only cleared if an explicit
+ * "clear peak" command is executed for the sensor in question.
+ */
+
+struct ltc2978_data {
+	enum chips id;
+	u16 vin_min, vin_max;
+	u16 temp_min[LTC2974_NUM_PAGES], temp_max[LTC2974_NUM_PAGES];
+	u16 vout_min[LTC2978_NUM_PAGES], vout_max[LTC2978_NUM_PAGES];
+	u16 iout_min[LTC2974_NUM_PAGES], iout_max[LTC2974_NUM_PAGES];
+	u16 iin_min, iin_max;
+	u16 pin_min, pin_max;
+	u16 temp2_max;
+	struct pmbus_driver_info info;
+	u32 features;
+};
+#define to_ltc2978_data(x)  container_of(x, struct ltc2978_data, info)
+
+#define FEAT_CLEAR_PEAKS	BIT(0)
+#define FEAT_NEEDS_POLLING	BIT(1)
+
+#define has_clear_peaks(d)	((d)->features & FEAT_CLEAR_PEAKS)
+#define needs_polling(d)	((d)->features & FEAT_NEEDS_POLLING)
+
+static int ltc_wait_ready(struct i2c_client *client)
+{
+	unsigned long timeout = jiffies + msecs_to_jiffies(LTC_POLL_TIMEOUT);
+	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
+	struct ltc2978_data *data = to_ltc2978_data(info);
+	int status;
+	u8 mask;
+
+	if (!needs_polling(data))
+		return 0;
+
+	/*
+	 * LTC3883 does not support LTC_NOT_PENDING, even though
+	 * the datasheet claims that it does.
+	 */
+	mask = LTC_NOT_BUSY;
+	if (data->id != ltc3883)
+		mask |= LTC_NOT_PENDING;
+
+	do {
+		status = pmbus_read_byte_data(client, 0, LTC2978_MFR_COMMON);
+		if (status == -EBADMSG || status == -ENXIO) {
+			/* PEC error or NACK: chip may be busy, try again */
+			usleep_range(50, 100);
+			continue;
+		}
+		if (status < 0)
+			return status;
+
+		if ((status & mask) == mask)
+			return 0;
+
+		usleep_range(50, 100);
+	} while (time_before(jiffies, timeout));
+
+	return -ETIMEDOUT;
+}
+
+static int ltc_read_word_data(struct i2c_client *client, int page, int phase,
+			      int reg)
+{
+	int ret;
+
+	ret = ltc_wait_ready(client);
+	if (ret < 0)
+		return ret;
+
+	return pmbus_read_word_data(client, page, 0xff, reg);
+}
+
+static int ltc_read_byte_data(struct i2c_client *client, int page, int reg)
+{
+	int ret;
+
+	ret = ltc_wait_ready(client);
+	if (ret < 0)
+		return ret;
+
+	return pmbus_read_byte_data(client, page, reg);
+}
+
+static int ltc_write_byte_data(struct i2c_client *client, int page, int reg, u8 value)
+{
+	int ret;
+
+	ret = ltc_wait_ready(client);
+	if (ret < 0)
+		return ret;
+
+	return pmbus_write_byte_data(client, page, reg, value);
+}
+
+static int ltc_write_byte(struct i2c_client *client, int page, u8 byte)
+{
+	int ret;
+
+	ret = ltc_wait_ready(client);
+	if (ret < 0)
+		return ret;
+
+	return pmbus_write_byte(client, page, byte);
+}
+
+static inline int lin11_to_val(int data)
+{
+	s16 e = ((s16)data) >> 11;
+	s32 m = (((s16)(data << 5)) >> 5);
+
+	/*
+	 * mantissa is 10 bit + sign, exponent adds up to 15 bit.
+	 * Add 6 bit to exponent for maximum accuracy (10 + 15 + 6 = 31).
+	 */
+	e += 6;
+	return (e < 0 ? m >> -e : m << e);
+}
+
+static int ltc_get_max(struct ltc2978_data *data, struct i2c_client *client,
+		       int page, int reg, u16 *pmax)
+{
+	int ret;
+
+	ret = ltc_read_word_data(client, page, 0xff, reg);
+	if (ret >= 0) {
+		if (lin11_to_val(ret) > lin11_to_val(*pmax))
+			*pmax = ret;
+		ret = *pmax;
+	}
+	return ret;
+}
+
+static int ltc_get_min(struct ltc2978_data *data, struct i2c_client *client,
+		       int page, int reg, u16 *pmin)
+{
+	int ret;
+
+	ret = ltc_read_word_data(client, page, 0xff, reg);
+	if (ret >= 0) {
+		if (lin11_to_val(ret) < lin11_to_val(*pmin))
+			*pmin = ret;
+		ret = *pmin;
+	}
+	return ret;
+}
+
+static int ltc2978_read_word_data_common(struct i2c_client *client, int page,
+					 int reg)
+{
+	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
+	struct ltc2978_data *data = to_ltc2978_data(info);
+	int ret;
+
+	switch (reg) {
+	case PMBUS_VIRT_READ_VIN_MAX:
+		ret = ltc_get_max(data, client, page, LTC2978_MFR_VIN_PEAK,
+				  &data->vin_max);
+		break;
+	case PMBUS_VIRT_READ_VOUT_MAX:
+		ret = ltc_read_word_data(client, page, 0xff,
+					 LTC2978_MFR_VOUT_PEAK);
+		if (ret >= 0) {
+			/*
+			 * VOUT is 16 bit unsigned with fixed exponent,
+			 * so we can compare it directly
+			 */
+			if (ret > data->vout_max[page])
+				data->vout_max[page] = ret;
+			ret = data->vout_max[page];
+		}
+		break;
+	case PMBUS_VIRT_READ_TEMP_MAX:
+		ret = ltc_get_max(data, client, page,
+				  LTC2978_MFR_TEMPERATURE_PEAK,
+				  &data->temp_max[page]);
+		break;
+	case PMBUS_VIRT_RESET_VOUT_HISTORY:
+	case PMBUS_VIRT_RESET_VIN_HISTORY:
+	case PMBUS_VIRT_RESET_TEMP_HISTORY:
+		ret = 0;
+		break;
+	default:
+		ret = ltc_wait_ready(client);
+		if (ret < 0)
+			return ret;
+		ret = -ENODATA;
+		break;
+	}
+	return ret;
+}
+
+static int ltc2978_read_word_data(struct i2c_client *client, int page,
+				  int phase, int reg)
+{
+	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
+	struct ltc2978_data *data = to_ltc2978_data(info);
+	int ret;
+
+	switch (reg) {
+	case PMBUS_VIRT_READ_VIN_MIN:
+		ret = ltc_get_min(data, client, page, LTC2978_MFR_VIN_MIN,
+				  &data->vin_min);
+		break;
+	case PMBUS_VIRT_READ_VOUT_MIN:
+		ret = ltc_read_word_data(client, page, phase,
+					 LTC2978_MFR_VOUT_MIN);
+		if (ret >= 0) {
+			/*
+			 * VOUT_MIN is known to not be supported on some lots
+			 * of LTC2978 revision 1, and will return the maximum
+			 * possible voltage if read. If VOUT_MAX is valid and
+			 * lower than the reading of VOUT_MIN, use it instead.
+			 */
+			if (data->vout_max[page] && ret > data->vout_max[page])
+				ret = data->vout_max[page];
+			if (ret < data->vout_min[page])
+				data->vout_min[page] = ret;
+			ret = data->vout_min[page];
+		}
+		break;
+	case PMBUS_VIRT_READ_TEMP_MIN:
+		ret = ltc_get_min(data, client, page,
+				  LTC2978_MFR_TEMPERATURE_MIN,
+				  &data->temp_min[page]);
+		break;
+	case PMBUS_VIRT_READ_IOUT_MAX:
+	case PMBUS_VIRT_RESET_IOUT_HISTORY:
+	case PMBUS_VIRT_READ_TEMP2_MAX:
+	case PMBUS_VIRT_RESET_TEMP2_HISTORY:
+		ret = -ENXIO;
+		break;
+	default:
+		ret = ltc2978_read_word_data_common(client, page, reg);
+		break;
+	}
+	return ret;
+}
+
+static int ltc2974_read_word_data(struct i2c_client *client, int page,
+				  int phase, int reg)
+{
+	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
+	struct ltc2978_data *data = to_ltc2978_data(info);
+	int ret;
+
+	switch (reg) {
+	case PMBUS_VIRT_READ_IOUT_MAX:
+		ret = ltc_get_max(data, client, page, LTC2974_MFR_IOUT_PEAK,
+				  &data->iout_max[page]);
+		break;
+	case PMBUS_VIRT_READ_IOUT_MIN:
+		ret = ltc_get_min(data, client, page, LTC2974_MFR_IOUT_MIN,
+				  &data->iout_min[page]);
+		break;
+	case PMBUS_VIRT_RESET_IOUT_HISTORY:
+		ret = 0;
+		break;
+	default:
+		ret = ltc2978_read_word_data(client, page, phase, reg);
+		break;
+	}
+	return ret;
+}
+
+static int ltc2975_read_word_data(struct i2c_client *client, int page,
+				  int phase, int reg)
+{
+	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
+	struct ltc2978_data *data = to_ltc2978_data(info);
+	int ret;
+
+	switch (reg) {
+	case PMBUS_VIRT_READ_IIN_MAX:
+		ret = ltc_get_max(data, client, page, LTC2975_MFR_IIN_PEAK,
+				  &data->iin_max);
+		break;
+	case PMBUS_VIRT_READ_IIN_MIN:
+		ret = ltc_get_min(data, client, page, LTC2975_MFR_IIN_MIN,
+				  &data->iin_min);
+		break;
+	case PMBUS_VIRT_READ_PIN_MAX:
+		ret = ltc_get_max(data, client, page, LTC2975_MFR_PIN_PEAK,
+				  &data->pin_max);
+		break;
+	case PMBUS_VIRT_READ_PIN_MIN:
+		ret = ltc_get_min(data, client, page, LTC2975_MFR_PIN_MIN,
+				  &data->pin_min);
+		break;
+	case PMBUS_VIRT_RESET_IIN_HISTORY:
+	case PMBUS_VIRT_RESET_PIN_HISTORY:
+		ret = 0;
+		break;
+	default:
+		ret = ltc2978_read_word_data(client, page, phase, reg);
+		break;
+	}
+	return ret;
+}
+
+static int ltc3880_read_word_data(struct i2c_client *client, int page,
+				  int phase, int reg)
+{
+	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
+	struct ltc2978_data *data = to_ltc2978_data(info);
+	int ret;
+
+	switch (reg) {
+	case PMBUS_VIRT_READ_IOUT_MAX:
+		ret = ltc_get_max(data, client, page, LTC3880_MFR_IOUT_PEAK,
+				  &data->iout_max[page]);
+		break;
+	case PMBUS_VIRT_READ_TEMP2_MAX:
+		ret = ltc_get_max(data, client, page,
+				  LTC3880_MFR_TEMPERATURE2_PEAK,
+				  &data->temp2_max);
+		break;
+	case PMBUS_VIRT_READ_VIN_MIN:
+	case PMBUS_VIRT_READ_VOUT_MIN:
+	case PMBUS_VIRT_READ_TEMP_MIN:
+		ret = -ENXIO;
+		break;
+	case PMBUS_VIRT_RESET_IOUT_HISTORY:
+	case PMBUS_VIRT_RESET_TEMP2_HISTORY:
+		ret = 0;
+		break;
+	default:
+		ret = ltc2978_read_word_data_common(client, page, reg);
+		break;
+	}
+	return ret;
+}
+
+static int ltc3883_read_word_data(struct i2c_client *client, int page,
+				  int phase, int reg)
+{
+	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
+	struct ltc2978_data *data = to_ltc2978_data(info);
+	int ret;
+
+	switch (reg) {
+	case PMBUS_VIRT_READ_IIN_MAX:
+		ret = ltc_get_max(data, client, page, LTC3883_MFR_IIN_PEAK,
+				  &data->iin_max);
+		break;
+	case PMBUS_VIRT_RESET_IIN_HISTORY:
+		ret = 0;
+		break;
+	default:
+		ret = ltc3880_read_word_data(client, page, phase, reg);
+		break;
+	}
+	return ret;
+}
+
+static int ltc2978_clear_peaks(struct ltc2978_data *data,
+			       struct i2c_client *client, int page)
+{
+	int ret;
+
+	if (has_clear_peaks(data))
+		ret = ltc_write_byte(client, 0, LTC3880_MFR_CLEAR_PEAKS);
+	else
+		ret = ltc_write_byte(client, page, PMBUS_CLEAR_FAULTS);
+
+	return ret;
+}
+
+static int ltc2978_write_word_data(struct i2c_client *client, int page,
+				    int reg, u16 word)
+{
+	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
+	struct ltc2978_data *data = to_ltc2978_data(info);
+	int ret;
+
+	switch (reg) {
+	case PMBUS_VIRT_RESET_IIN_HISTORY:
+		data->iin_max = 0x7c00;
+		data->iin_min = 0x7bff;
+		ret = ltc2978_clear_peaks(data, client, 0);
+		break;
+	case PMBUS_VIRT_RESET_PIN_HISTORY:
+		data->pin_max = 0x7c00;
+		data->pin_min = 0x7bff;
+		ret = ltc2978_clear_peaks(data, client, 0);
+		break;
+	case PMBUS_VIRT_RESET_IOUT_HISTORY:
+		data->iout_max[page] = 0x7c00;
+		data->iout_min[page] = 0xfbff;
+		ret = ltc2978_clear_peaks(data, client, page);
+		break;
+	case PMBUS_VIRT_RESET_TEMP2_HISTORY:
+		data->temp2_max = 0x7c00;
+		ret = ltc2978_clear_peaks(data, client, page);
+		break;
+	case PMBUS_VIRT_RESET_VOUT_HISTORY:
+		data->vout_min[page] = 0xffff;
+		data->vout_max[page] = 0;
+		ret = ltc2978_clear_peaks(data, client, page);
+		break;
+	case PMBUS_VIRT_RESET_VIN_HISTORY:
+		data->vin_min = 0x7bff;
+		data->vin_max = 0x7c00;
+		ret = ltc2978_clear_peaks(data, client, page);
+		break;
+	case PMBUS_VIRT_RESET_TEMP_HISTORY:
+		data->temp_min[page] = 0x7bff;
+		data->temp_max[page] = 0x7c00;
+		ret = ltc2978_clear_peaks(data, client, page);
+		break;
+	default:
+		ret = ltc_wait_ready(client);
+		if (ret < 0)
+			return ret;
+		ret = -ENODATA;
+		break;
+	}
+	return ret;
+}
+
+static const struct i2c_device_id ltc2978_id[] = {
+	{"ltc2972", ltc2972},
+	{"ltc2974", ltc2974},
+	{"ltc2975", ltc2975},
+	{"ltc2977", ltc2977},
+	{"ltc2978", ltc2978},
+	{"ltc2979", ltc2979},
+	{"ltc2980", ltc2980},
+	{"ltc3880", ltc3880},
+	{"ltc3882", ltc3882},
+	{"ltc3883", ltc3883},
+	{"ltc3884", ltc3884},
+	{"ltc3886", ltc3886},
+	{"ltc3887", ltc3887},
+	{"ltc3889", ltc3889},
+	{"ltc7880", ltc7880},
+	{"ltm2987", ltm2987},
+	{"ltm4664", ltm4664},
+	{"ltm4675", ltm4675},
+	{"ltm4676", ltm4676},
+	{"ltm4677", ltm4677},
+	{"ltm4678", ltm4678},
+	{"ltm4680", ltm4680},
+	{"ltm4686", ltm4686},
+	{"ltm4700", ltm4700},
+	{}
+};
+MODULE_DEVICE_TABLE(i2c, ltc2978_id);
+
+#if IS_ENABLED(CONFIG_SENSORS_LTC2978_REGULATOR)
+#define LTC2978_ADC_RES	0xFFFF
+#define LTC2978_N_ADC	122
+#define LTC2978_MAX_UV	(LTC2978_ADC_RES * LTC2978_N_ADC)
+#define LTC2978_UV_STEP	1000
+#define LTC2978_N_VOLTAGES	((LTC2978_MAX_UV / LTC2978_UV_STEP) + 1)
+
+static const struct regulator_desc ltc2978_reg_desc[] = {
+	PMBUS_REGULATOR_STEP("vout", 0, LTC2978_N_VOLTAGES, LTC2978_UV_STEP),
+	PMBUS_REGULATOR_STEP("vout", 1, LTC2978_N_VOLTAGES, LTC2978_UV_STEP),
+	PMBUS_REGULATOR_STEP("vout", 2, LTC2978_N_VOLTAGES, LTC2978_UV_STEP),
+	PMBUS_REGULATOR_STEP("vout", 3, LTC2978_N_VOLTAGES, LTC2978_UV_STEP),
+	PMBUS_REGULATOR_STEP("vout", 4, LTC2978_N_VOLTAGES, LTC2978_UV_STEP),
+	PMBUS_REGULATOR_STEP("vout", 5, LTC2978_N_VOLTAGES, LTC2978_UV_STEP),
+	PMBUS_REGULATOR_STEP("vout", 6, LTC2978_N_VOLTAGES, LTC2978_UV_STEP),
+	PMBUS_REGULATOR_STEP("vout", 7, LTC2978_N_VOLTAGES, LTC2978_UV_STEP),
+};
+
+static const struct regulator_desc ltc2978_reg_desc_default[] = {
+	PMBUS_REGULATOR("vout", 0),
+	PMBUS_REGULATOR("vout", 1),
+	PMBUS_REGULATOR("vout", 2),
+	PMBUS_REGULATOR("vout", 3),
+	PMBUS_REGULATOR("vout", 4),
+	PMBUS_REGULATOR("vout", 5),
+	PMBUS_REGULATOR("vout", 6),
+	PMBUS_REGULATOR("vout", 7),
+};
+#endif /* CONFIG_SENSORS_LTC2978_REGULATOR */
+
+static int ltc2978_get_id(struct i2c_client *client)
+{
+	int chip_id;
+
+	chip_id = i2c_smbus_read_word_data(client, LTC2978_MFR_SPECIAL_ID);
+	if (chip_id < 0) {
+		const struct i2c_device_id *id;
+		u8 buf[I2C_SMBUS_BLOCK_MAX];
+		int ret;
+
+		if (!i2c_check_functionality(client->adapter,
+					     I2C_FUNC_SMBUS_READ_BLOCK_DATA))
+			return -ENODEV;
+
+		ret = i2c_smbus_read_block_data(client, PMBUS_MFR_ID, buf);
+		if (ret < 0)
+			return ret;
+		if (ret < 3 || strncmp(buf, "LTC", 3))
+			return -ENODEV;
+
+		ret = i2c_smbus_read_block_data(client, PMBUS_MFR_MODEL, buf);
+		if (ret < 0)
+			return ret;
+		for (id = &ltc2978_id[0]; strlen(id->name); id++) {
+			if (!strncasecmp(id->name, buf, strlen(id->name)))
+				return (int)id->driver_data;
+		}
+		return -ENODEV;
+	}
+
+	chip_id &= LTC2978_ID_MASK;
+
+	if (chip_id == LTC2972_ID)
+		return ltc2972;
+	else if (chip_id == LTC2974_ID)
+		return ltc2974;
+	else if (chip_id == LTC2975_ID)
+		return ltc2975;
+	else if (chip_id == LTC2977_ID)
+		return ltc2977;
+	else if (chip_id == LTC2978_ID_REV1 || chip_id == LTC2978_ID_REV2)
+		return ltc2978;
+	else if (chip_id == LTC2979_ID_A || chip_id == LTC2979_ID_B)
+		return ltc2979;
+	else if (chip_id == LTC2980_ID_A || chip_id == LTC2980_ID_B)
+		return ltc2980;
+	else if (chip_id == LTC3880_ID)
+		return ltc3880;
+	else if (chip_id == LTC3882_ID || chip_id == LTC3882_ID_D1)
+		return ltc3882;
+	else if (chip_id == LTC3883_ID)
+		return ltc3883;
+	else if (chip_id == LTC3884_ID)
+		return ltc3884;
+	else if (chip_id == LTC3886_ID)
+		return ltc3886;
+	else if (chip_id == LTC3887_ID)
+		return ltc3887;
+	else if (chip_id == LTC3889_ID)
+		return ltc3889;
+	else if (chip_id == LTC7880_ID)
+		return ltc7880;
+	else if (chip_id == LTM2987_ID_A || chip_id == LTM2987_ID_B)
+		return ltm2987;
+	else if (chip_id == LTM4664_ID)
+		return ltm4664;
+	else if (chip_id == LTM4675_ID)
+		return ltm4675;
+	else if (chip_id == LTM4676_ID_REV1 || chip_id == LTM4676_ID_REV2 ||
+		 chip_id == LTM4676A_ID)
+		return ltm4676;
+	else if (chip_id == LTM4677_ID_REV1 || chip_id == LTM4677_ID_REV2)
+		return ltm4677;
+	else if (chip_id == LTM4678_ID_REV1 || chip_id == LTM4678_ID_REV2)
+		return ltm4678;
+	else if (chip_id == LTM4680_ID)
+		return ltm4680;
+	else if (chip_id == LTM4686_ID)
+		return ltm4686;
+	else if (chip_id == LTM4700_ID)
+		return ltm4700;
+
+	dev_err(&client->dev, "Unsupported chip ID 0x%x\n", chip_id);
+	return -ENODEV;
+}
+
+static int ltc2978_probe(struct i2c_client *client)
+{
+	int i, chip_id;
+	struct ltc2978_data *data;
+	struct pmbus_driver_info *info;
+	const struct i2c_device_id *id;
+
+	if (!i2c_check_functionality(client->adapter,
+				     I2C_FUNC_SMBUS_READ_WORD_DATA))
+		return -ENODEV;
+
+	data = devm_kzalloc(&client->dev, sizeof(struct ltc2978_data),
+			    GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	chip_id = ltc2978_get_id(client);
+	if (chip_id < 0)
+		return chip_id;
+
+	data->id = chip_id;
+	id = i2c_match_id(ltc2978_id, client);
+	if (data->id != id->driver_data)
+		dev_warn(&client->dev,
+			 "Device mismatch: Configured %s (%d), detected %d\n",
+			 id->name,
+			 (int) id->driver_data,
+			 chip_id);
+
+	info = &data->info;
+	info->write_word_data = ltc2978_write_word_data;
+	info->write_byte = ltc_write_byte;
+	info->write_byte_data = ltc_write_byte_data;
+	info->read_word_data = ltc_read_word_data;
+	info->read_byte_data = ltc_read_byte_data;
+
+	data->vin_min = 0x7bff;
+	data->vin_max = 0x7c00;
+	for (i = 0; i < ARRAY_SIZE(data->vout_min); i++)
+		data->vout_min[i] = 0xffff;
+	for (i = 0; i < ARRAY_SIZE(data->iout_min); i++)
+		data->iout_min[i] = 0xfbff;
+	for (i = 0; i < ARRAY_SIZE(data->iout_max); i++)
+		data->iout_max[i] = 0x7c00;
+	for (i = 0; i < ARRAY_SIZE(data->temp_min); i++)
+		data->temp_min[i] = 0x7bff;
+	for (i = 0; i < ARRAY_SIZE(data->temp_max); i++)
+		data->temp_max[i] = 0x7c00;
+	data->temp2_max = 0x7c00;
+
+	switch (data->id) {
+	case ltc2972:
+		info->read_word_data = ltc2975_read_word_data;
+		info->pages = LTC2972_NUM_PAGES;
+		info->func[0] = PMBUS_HAVE_IIN | PMBUS_HAVE_PIN
+		  | PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT
+		  | PMBUS_HAVE_TEMP2;
+		for (i = 0; i < info->pages; i++) {
+			info->func[i] |= PMBUS_HAVE_VOUT
+			  | PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_POUT
+			  | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP
+			  | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT;
+		}
+		break;
+	case ltc2974:
+		info->read_word_data = ltc2974_read_word_data;
+		info->pages = LTC2974_NUM_PAGES;
+		info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT
+		  | PMBUS_HAVE_TEMP2;
+		for (i = 0; i < info->pages; i++) {
+			info->func[i] |= PMBUS_HAVE_VOUT
+			  | PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_POUT
+			  | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP
+			  | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT;
+		}
+		break;
+	case ltc2975:
+		info->read_word_data = ltc2975_read_word_data;
+		info->pages = LTC2974_NUM_PAGES;
+		info->func[0] = PMBUS_HAVE_IIN | PMBUS_HAVE_PIN
+		  | PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT
+		  | PMBUS_HAVE_TEMP2;
+		for (i = 0; i < info->pages; i++) {
+			info->func[i] |= PMBUS_HAVE_VOUT
+			  | PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_POUT
+			  | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP
+			  | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT;
+		}
+		break;
+
+	case ltc2977:
+	case ltc2978:
+	case ltc2979:
+	case ltc2980:
+	case ltm2987:
+		info->read_word_data = ltc2978_read_word_data;
+		info->pages = LTC2978_NUM_PAGES;
+		info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT
+		  | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
+		  | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP;
+		for (i = 1; i < LTC2978_NUM_PAGES; i++) {
+			info->func[i] = PMBUS_HAVE_VOUT
+			  | PMBUS_HAVE_STATUS_VOUT;
+		}
+		break;
+	case ltc3880:
+	case ltc3887:
+	case ltm4675:
+	case ltm4676:
+	case ltm4677:
+	case ltm4686:
+		data->features |= FEAT_CLEAR_PEAKS | FEAT_NEEDS_POLLING;
+		info->read_word_data = ltc3880_read_word_data;
+		info->pages = LTC3880_NUM_PAGES;
+		info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_IIN
+		  | PMBUS_HAVE_STATUS_INPUT
+		  | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
+		  | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
+		  | PMBUS_HAVE_POUT | PMBUS_HAVE_TEMP
+		  | PMBUS_HAVE_TEMP2 | PMBUS_HAVE_STATUS_TEMP;
+		info->func[1] = PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
+		  | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
+		  | PMBUS_HAVE_POUT
+		  | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP;
+		break;
+	case ltc3882:
+		data->features |= FEAT_CLEAR_PEAKS | FEAT_NEEDS_POLLING;
+		info->read_word_data = ltc3880_read_word_data;
+		info->pages = LTC3880_NUM_PAGES;
+		info->func[0] = PMBUS_HAVE_VIN
+		  | PMBUS_HAVE_STATUS_INPUT
+		  | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
+		  | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
+		  | PMBUS_HAVE_POUT | PMBUS_HAVE_TEMP
+		  | PMBUS_HAVE_TEMP2 | PMBUS_HAVE_STATUS_TEMP;
+		info->func[1] = PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
+		  | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
+		  | PMBUS_HAVE_POUT
+		  | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP;
+		break;
+	case ltc3883:
+		data->features |= FEAT_CLEAR_PEAKS | FEAT_NEEDS_POLLING;
+		info->read_word_data = ltc3883_read_word_data;
+		info->pages = LTC3883_NUM_PAGES;
+		info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_IIN
+		  | PMBUS_HAVE_STATUS_INPUT
+		  | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
+		  | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
+		  | PMBUS_HAVE_PIN | PMBUS_HAVE_POUT | PMBUS_HAVE_TEMP
+		  | PMBUS_HAVE_TEMP2 | PMBUS_HAVE_STATUS_TEMP;
+		break;
+	case ltc3884:
+	case ltc3886:
+	case ltc3889:
+	case ltc7880:
+	case ltm4664:
+	case ltm4678:
+	case ltm4680:
+	case ltm4700:
+		data->features |= FEAT_CLEAR_PEAKS | FEAT_NEEDS_POLLING;
+		info->read_word_data = ltc3883_read_word_data;
+		info->pages = LTC3880_NUM_PAGES;
+		info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_IIN
+		  | PMBUS_HAVE_STATUS_INPUT
+		  | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
+		  | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
+		  | PMBUS_HAVE_PIN | PMBUS_HAVE_POUT | PMBUS_HAVE_TEMP
+		  | PMBUS_HAVE_TEMP2 | PMBUS_HAVE_STATUS_TEMP;
+		info->func[1] = PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
+		  | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
+		  | PMBUS_HAVE_POUT
+		  | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP;
+		break;
+	default:
+		return -ENODEV;
+	}
+
+#if IS_ENABLED(CONFIG_SENSORS_LTC2978_REGULATOR)
+	info->num_regulators = info->pages;
+	switch (data->id) {
+	case ltc2972:
+	case ltc2974:
+	case ltc2975:
+	case ltc2977:
+	case ltc2978:
+	case ltc2979:
+	case ltc2980:
+	case ltm2987:
+		info->reg_desc = ltc2978_reg_desc;
+		if (info->num_regulators > ARRAY_SIZE(ltc2978_reg_desc)) {
+			dev_warn(&client->dev, "num_regulators too large!");
+			info->num_regulators = ARRAY_SIZE(ltc2978_reg_desc);
+		}
+		break;
+	default:
+		info->reg_desc = ltc2978_reg_desc_default;
+		if (info->num_regulators > ARRAY_SIZE(ltc2978_reg_desc_default)) {
+			dev_warn(&client->dev, "num_regulators too large!");
+			info->num_regulators =
+			    ARRAY_SIZE(ltc2978_reg_desc_default);
+		}
+		break;
+	}
+#endif
+
+	return pmbus_do_probe(client, info);
+}
+
+
+#ifdef CONFIG_OF
+static const struct of_device_id ltc2978_of_match[] = {
+	{ .compatible = "lltc,ltc2972" },
+	{ .compatible = "lltc,ltc2974" },
+	{ .compatible = "lltc,ltc2975" },
+	{ .compatible = "lltc,ltc2977" },
+	{ .compatible = "lltc,ltc2978" },
+	{ .compatible = "lltc,ltc2979" },
+	{ .compatible = "lltc,ltc2980" },
+	{ .compatible = "lltc,ltc3880" },
+	{ .compatible = "lltc,ltc3882" },
+	{ .compatible = "lltc,ltc3883" },
+	{ .compatible = "lltc,ltc3884" },
+	{ .compatible = "lltc,ltc3886" },
+	{ .compatible = "lltc,ltc3887" },
+	{ .compatible = "lltc,ltc3889" },
+	{ .compatible = "lltc,ltc7880" },
+	{ .compatible = "lltc,ltm2987" },
+	{ .compatible = "lltc,ltm4664" },
+	{ .compatible = "lltc,ltm4675" },
+	{ .compatible = "lltc,ltm4676" },
+	{ .compatible = "lltc,ltm4677" },
+	{ .compatible = "lltc,ltm4678" },
+	{ .compatible = "lltc,ltm4680" },
+	{ .compatible = "lltc,ltm4686" },
+	{ .compatible = "lltc,ltm4700" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ltc2978_of_match);
+#endif
+
+static struct i2c_driver ltc2978_driver = {
+	.driver = {
+		   .name = "ltc2978",
+		   .of_match_table = of_match_ptr(ltc2978_of_match),
+		   },
+	.probe_new = ltc2978_probe,
+	.id_table = ltc2978_id,
+};
+
+module_i2c_driver(ltc2978_driver);
+
+MODULE_AUTHOR("Guenter Roeck");
+MODULE_DESCRIPTION("PMBus driver for LTC2978 and compatible chips");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS(PMBUS);