Initial import

1 files changed, 544 insertions, 0 deletions

diff --git a/drivers/hwmon/pmbus/ltc2978.c b/drivers/hwmon/pmbus/ltc2978.c
new file mode 100644
index 000000000..0835050ec
--- /dev/null
+++ b/drivers/hwmon/pmbus/ltc2978.c
@@ -0,0 +1,544 @@
+/*
+ * Hardware monitoring driver for LTC2974, LTC2977, LTC2978, LTC3880,
+ * LTC3883, and LTM4676
+ *
+ * Copyright (c) 2011 Ericsson AB.
+ * Copyright (c) 2013, 2014 Guenter Roeck
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#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 { ltc2974, ltc2977, ltc2978, ltc3880, ltc3883, ltm4676 };
+
+/* 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
+
+/* LTC2974, LCT2977, and LTC2978 */
+#define LTC2978_MFR_VOUT_MIN		0xfb
+#define LTC2978_MFR_VIN_MIN		0xfc
+#define LTC2978_MFR_TEMPERATURE_MIN	0xfd
+
+/* LTC2974 only */
+#define LTC2974_MFR_IOUT_PEAK		0xd7
+#define LTC2974_MFR_IOUT_MIN		0xd8
+
+/* LTC3880, LTC3883, and LTM4676 */
+#define LTC3880_MFR_IOUT_PEAK		0xd7
+#define LTC3880_MFR_CLEAR_PEAKS		0xe3
+#define LTC3880_MFR_TEMPERATURE2_PEAK	0xf4
+
+/* LTC3883 only */
+#define LTC3883_MFR_IIN_PEAK		0xe1
+
+#define LTC2974_ID_REV1			0x0212
+#define LTC2974_ID_REV2			0x0213
+#define LTC2977_ID			0x0130
+#define LTC2978_ID_REV1			0x0121
+#define LTC2978_ID_REV2			0x0122
+#define LTC2978A_ID			0x0124
+#define LTC3880_ID			0x4000
+#define LTC3880_ID_MASK			0xff00
+#define LTC3883_ID			0x4300
+#define LTC3883_ID_MASK			0xff00
+#define LTM4676_ID			0x4480	/* datasheet claims 0x440X */
+#define LTM4676_ID_MASK			0xfff0
+
+#define LTC2974_NUM_PAGES		4
+#define LTC2978_NUM_PAGES		8
+#define LTC3880_NUM_PAGES		2
+#define LTC3883_NUM_PAGES		1
+
+/*
+ * 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_max;
+	u16 temp2_max;
+	struct pmbus_driver_info info;
+};
+
+#define to_ltc2978_data(x)  container_of(x, struct ltc2978_data, info)
+
+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 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 = pmbus_read_word_data(client, page, LTC2978_MFR_VIN_PEAK);
+		if (ret >= 0) {
+			if (lin11_to_val(ret) > lin11_to_val(data->vin_max))
+				data->vin_max = ret;
+			ret = data->vin_max;
+		}
+		break;
+	case PMBUS_VIRT_READ_VOUT_MAX:
+		ret = pmbus_read_word_data(client, page, 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 = pmbus_read_word_data(client, page,
+					   LTC2978_MFR_TEMPERATURE_PEAK);
+		if (ret >= 0) {
+			if (lin11_to_val(ret)
+			    > lin11_to_val(data->temp_max[page]))
+				data->temp_max[page] = ret;
+			ret = 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 = -ENODATA;
+		break;
+	}
+	return ret;
+}
+
+static int ltc2978_read_word_data(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_MIN:
+		ret = pmbus_read_word_data(client, page, LTC2978_MFR_VIN_MIN);
+		if (ret >= 0) {
+			if (lin11_to_val(ret) < lin11_to_val(data->vin_min))
+				data->vin_min = ret;
+			ret = data->vin_min;
+		}
+		break;
+	case PMBUS_VIRT_READ_VOUT_MIN:
+		ret = pmbus_read_word_data(client, page, 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 = pmbus_read_word_data(client, page,
+					   LTC2978_MFR_TEMPERATURE_MIN);
+		if (ret >= 0) {
+			if (lin11_to_val(ret)
+			    < lin11_to_val(data->temp_min[page]))
+				data->temp_min[page] = ret;
+			ret = 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 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 = pmbus_read_word_data(client, page, LTC2974_MFR_IOUT_PEAK);
+		if (ret >= 0) {
+			if (lin11_to_val(ret)
+			    > lin11_to_val(data->iout_max[page]))
+				data->iout_max[page] = ret;
+			ret = data->iout_max[page];
+		}
+		break;
+	case PMBUS_VIRT_READ_IOUT_MIN:
+		ret = pmbus_read_word_data(client, page, LTC2974_MFR_IOUT_MIN);
+		if (ret >= 0) {
+			if (lin11_to_val(ret)
+			    < lin11_to_val(data->iout_min[page]))
+				data->iout_min[page] = ret;
+			ret = data->iout_min[page];
+		}
+		break;
+	case PMBUS_VIRT_RESET_IOUT_HISTORY:
+		ret = 0;
+		break;
+	default:
+		ret = ltc2978_read_word_data(client, page, reg);
+		break;
+	}
+	return ret;
+}
+
+static int ltc3880_read_word_data(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_IOUT_MAX:
+		ret = pmbus_read_word_data(client, page, LTC3880_MFR_IOUT_PEAK);
+		if (ret >= 0) {
+			if (lin11_to_val(ret)
+			    > lin11_to_val(data->iout_max[page]))
+				data->iout_max[page] = ret;
+			ret = data->iout_max[page];
+		}
+		break;
+	case PMBUS_VIRT_READ_TEMP2_MAX:
+		ret = pmbus_read_word_data(client, page,
+					   LTC3880_MFR_TEMPERATURE2_PEAK);
+		if (ret >= 0) {
+			if (lin11_to_val(ret) > lin11_to_val(data->temp2_max))
+				data->temp2_max = ret;
+			ret = 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 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 = pmbus_read_word_data(client, page, LTC3883_MFR_IIN_PEAK);
+		if (ret >= 0) {
+			if (lin11_to_val(ret)
+			    > lin11_to_val(data->iin_max))
+				data->iin_max = ret;
+			ret = data->iin_max;
+		}
+		break;
+	case PMBUS_VIRT_RESET_IIN_HISTORY:
+		ret = 0;
+		break;
+	default:
+		ret = ltc3880_read_word_data(client, page, reg);
+		break;
+	}
+	return ret;
+}
+
+static int ltc2978_clear_peaks(struct i2c_client *client, int page,
+			       enum chips id)
+{
+	int ret;
+
+	if (id == ltc3880 || id == ltc3883)
+		ret = pmbus_write_byte(client, 0, LTC3880_MFR_CLEAR_PEAKS);
+	else
+		ret = pmbus_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;
+		ret = ltc2978_clear_peaks(client, page, data->id);
+		break;
+	case PMBUS_VIRT_RESET_IOUT_HISTORY:
+		data->iout_max[page] = 0x7c00;
+		data->iout_min[page] = 0xfbff;
+		ret = ltc2978_clear_peaks(client, page, data->id);
+		break;
+	case PMBUS_VIRT_RESET_TEMP2_HISTORY:
+		data->temp2_max = 0x7c00;
+		ret = ltc2978_clear_peaks(client, page, data->id);
+		break;
+	case PMBUS_VIRT_RESET_VOUT_HISTORY:
+		data->vout_min[page] = 0xffff;
+		data->vout_max[page] = 0;
+		ret = ltc2978_clear_peaks(client, page, data->id);
+		break;
+	case PMBUS_VIRT_RESET_VIN_HISTORY:
+		data->vin_min = 0x7bff;
+		data->vin_max = 0x7c00;
+		ret = ltc2978_clear_peaks(client, page, data->id);
+		break;
+	case PMBUS_VIRT_RESET_TEMP_HISTORY:
+		data->temp_min[page] = 0x7bff;
+		data->temp_max[page] = 0x7c00;
+		ret = ltc2978_clear_peaks(client, page, data->id);
+		break;
+	default:
+		ret = -ENODATA;
+		break;
+	}
+	return ret;
+}
+
+static const struct i2c_device_id ltc2978_id[] = {
+	{"ltc2974", ltc2974},
+	{"ltc2977", ltc2977},
+	{"ltc2978", ltc2978},
+	{"ltc3880", ltc3880},
+	{"ltc3883", ltc3883},
+	{"ltm4676", ltm4676},
+	{}
+};
+MODULE_DEVICE_TABLE(i2c, ltc2978_id);
+
+#if IS_ENABLED(CONFIG_SENSORS_LTC2978_REGULATOR)
+static const struct regulator_desc ltc2978_reg_desc[] = {
+	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_probe(struct i2c_client *client,
+			 const struct i2c_device_id *id)
+{
+	int chip_id, i;
+	struct ltc2978_data *data;
+	struct pmbus_driver_info *info;
+
+	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 = i2c_smbus_read_word_data(client, LTC2978_MFR_SPECIAL_ID);
+	if (chip_id < 0)
+		return chip_id;
+
+	if (chip_id == LTC2974_ID_REV1 || chip_id == LTC2974_ID_REV2) {
+		data->id = ltc2974;
+	} else if (chip_id == LTC2977_ID) {
+		data->id = ltc2977;
+	} else if (chip_id == LTC2978_ID_REV1 || chip_id == LTC2978_ID_REV2 ||
+		   chip_id == LTC2978A_ID) {
+		data->id = ltc2978;
+	} else if ((chip_id & LTC3880_ID_MASK) == LTC3880_ID) {
+		data->id = ltc3880;
+	} else if ((chip_id & LTC3883_ID_MASK) == LTC3883_ID) {
+		data->id = ltc3883;
+	} else if ((chip_id & LTM4676_ID_MASK) == LTM4676_ID) {
+		data->id = ltm4676;
+	} else {
+		dev_err(&client->dev, "Unsupported chip ID 0x%x\n", chip_id);
+		return -ENODEV;
+	}
+	if (data->id != id->driver_data)
+		dev_warn(&client->dev,
+			 "Device mismatch: Configured %s, detected %s\n",
+			 id->name,
+			 ltc2978_id[data->id].name);
+
+	info = &data->info;
+	info->write_word_data = ltc2978_write_word_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 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 ltc2977:
+	case ltc2978:
+		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 ltm4676:
+		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 ltc3883:
+		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;
+	default:
+		return -ENODEV;
+	}
+
+#if IS_ENABLED(CONFIG_SENSORS_LTC2978_REGULATOR)
+	info->num_regulators = info->pages;
+	info->reg_desc = ltc2978_reg_desc;
+	if (info->num_regulators > ARRAY_SIZE(ltc2978_reg_desc)) {
+		dev_err(&client->dev, "num_regulators too large!");
+		info->num_regulators = ARRAY_SIZE(ltc2978_reg_desc);
+	}
+#endif
+
+	return pmbus_do_probe(client, id, info);
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id ltc2978_of_match[] = {
+	{ .compatible = "lltc,ltc2974" },
+	{ .compatible = "lltc,ltc2977" },
+	{ .compatible = "lltc,ltc2978" },
+	{ .compatible = "lltc,ltc3880" },
+	{ .compatible = "lltc,ltc3883" },
+	{ .compatible = "lltc,ltm4676" },
+	{ }
+};
+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 = ltc2978_probe,
+	.remove = pmbus_do_remove,
+	.id_table = ltc2978_id,
+};
+
+module_i2c_driver(ltc2978_driver);
+
+MODULE_AUTHOR("Guenter Roeck");
+MODULE_DESCRIPTION("PMBus driver for LTC2974, LTC2978, LTC3880, LTC3883, and LTM4676");
+MODULE_LICENSE("GPL");