MAX6621 is a PECI-to-I2C translator provides an efficient, low-cost
solution for PECI-to-SMBus/I2C protocol conversion. It allows reading the
temperature from the PECI-compliant host directly from up to four
PECI-enabled CPUs.
Signed-off-by: Vadim Pasternak <vadimp@xxxxxxxxxxxx>
---
v1->v2
Comments pointed out by Guenter:
- arrange includes in alphabetic order;
- add include for bitops.h;
- remove MAX6621_REG_NON_WRITEABLE_REG;
- drop temp_min, temp_max, temp_reset_history attributes;
- remove redundant braces in max6621_verify_reg_data;
- fix return code in max6621_verify_reg_data;
- not report channels which are not physically connected;
- use u32 for regval in max6621_read and max6621_write;
- provide in temprature offset in milli-degrees C;
- drop hwmon_temp_fault attribute;
- drop activation point setting in CONFIG2 reg, leave it for user space;
Comments pointed out by Jiri:
- fixe device name;
Fixes added by Vadim:
- modify names in max6621_temp_labels;
- add hwmon_temp_alarm attribute and hwmon_temp_crit attributes per
socket;
- fix defines for MIN and MAX temperature;
---
drivers/hwmon/Kconfig | 14 ++
drivers/hwmon/Makefile | 1 +
drivers/hwmon/max6621.c | 484 ++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 499 insertions(+)
create mode 100644 drivers/hwmon/max6621.c
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 5b9a61f..325d161 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -855,6 +855,20 @@ tristate "MAX31722 temperature sensor"
This driver can also be built as a module. If so, the module
will be called max31722.
+config SENSORS_MAX6621
+ tristate "Maxim MAX6621 sensor chip"
+ depends on I2C
+ select REGMAP_I2C
+ help
+ If you say yes here you get support for MAX6621 sensor chip.
+ MAX6621 is a PECI-to-I2C translator provides an efficient,
+ low-cost solution for PECI-to-SMBus/I2C protocol conversion.
+ It allows reading the temperature from the PECI-compliant
+ host directly from up to four PECI-enabled CPUs.
+
+ This driver can also be built as a module. If so, the module
+ will be called max6621.
+
config SENSORS_MAX6639
tristate "Maxim MAX6639 sensor chip"
depends on I2C
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index d4641a9..43333cb 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -116,6 +116,7 @@ obj-$(CONFIG_SENSORS_MAX1619) += max1619.o
obj-$(CONFIG_SENSORS_MAX1668) += max1668.o
obj-$(CONFIG_SENSORS_MAX197) += max197.o
obj-$(CONFIG_SENSORS_MAX31722) += max31722.o
+obj-$(CONFIG_SENSORS_MAX6621) += max6621.o
obj-$(CONFIG_SENSORS_MAX6639) += max6639.o
obj-$(CONFIG_SENSORS_MAX6642) += max6642.o
obj-$(CONFIG_SENSORS_MAX6650) += max6650.o
diff --git a/drivers/hwmon/max6621.c b/drivers/hwmon/max6621.c
new file mode 100644
index 0000000..2ad7fad
--- /dev/null
+++ b/drivers/hwmon/max6621.c
@@ -0,0 +1,484 @@
+/*
+ * Hardware monitoring driver for Maxim MAX6621
+ *
+ * Copyright (c) 2017 Mellanox Technologies. All rights reserved.
+ * Copyright (c) 2017 Vadim Pasternak <vadimp@xxxxxxxxxxxx>
+ *
+ * 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/bitops.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/of_device.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+
+#define MAX6621_DRV_NAME "max6621"
+#define MAX6621_TEMP_INPUT_REG_NUM 9
+#define MAX6621_TEMP_INPUT_MIN -20000
+#define MAX6621_TEMP_INPUT_MAX 120000
+
+#define MAX6621_TEMP_S0D0_REG 0x00
+#define MAX6621_TEMP_S0D1_REG 0x01
+#define MAX6621_TEMP_S1D0_REG 0x02
+#define MAX6621_TEMP_S1D1_REG 0x03
+#define MAX6621_TEMP_S2D0_REG 0x04
+#define MAX6621_TEMP_S2D1_REG 0x05
+#define MAX6621_TEMP_S3D0_REG 0x06
+#define MAX6621_TEMP_S3D1_REG 0x07
+#define MAX6621_TEMP_MAX_REG 0x08
+#define MAX6621_TEMP_ALERT_CAUSE 0x0b
+#define MAX6621_TEMP_MAX_ADDR_REG 0x0a
+#define MAX6621_CONFIG0_REG 0x0c
+#define MAX6621_CONFIG1_REG 0x0d
+#define MAX6621_CONFIG2_REG 0x0e
+#define MAX6621_CONFIG3_REG 0x0f
+#define MAX6621_TEMP_S0_ALERT_REG 0x10
+#define MAX6621_TEMP_S1_ALERT_REG 0x11
+#define MAX6621_TEMP_S2_ALERT_REG 0x12
+#define MAX6621_TEMP_S3_ALERT_REG 0x13
+#define MAX6621_CLEAR_ALERT_REG 0x15
+#define MAX6621_REG_MAX (MAX6621_CLEAR_ALERT_REG + 1)
+#define MAX6621_REG_TEMP_SHIFT 0x06
+
+#define MAX6621_ENABLE_TEMP_ALERTS_BIT 4
+#define MAX6621_ENABLE_I2C_CRC_BIT 5
+#define MAX6621_ENABLE_ALTERNATE_DATA 6
+#define MAX6621_ENABLE_LOCKUP_TO 7
+#define MAX6621_ENABLE_S0D0_BIT 8
+#define MAX6621_ENABLE_S0D1_BIT 9
+#define MAX6621_ENABLE_S1D0_BIT 10
+#define MAX6621_ENABLE_S1D1_BIT 11
+#define MAX6621_ENABLE_S2D0_BIT 12
+#define MAX6621_ENABLE_S2D1_BIT 13
+#define MAX6621_ENABLE_S3D0_BIT 14
+#define MAX6621_ENABLE_S3D1_BIT 15
+#define MAX6621_ENABLE_TEMP_ALL GENMASK(MAX6621_ENABLE_S3D1_BIT, \
+ MAX6621_ENABLE_S0D0_BIT)
+#define MAX6621_POLL_DELAY_MASK 0x5
+#define MAX6621_CONFIG0_INIT (MAX6621_ENABLE_TEMP_ALL | \
+ BIT(MAX6621_ENABLE_LOCKUP_TO) | \
+ BIT(MAX6621_ENABLE_I2C_CRC_BIT) | \
+ MAX6621_POLL_DELAY_MASK)
+
+/* Error codes */
+#define MAX6621_TRAN_FAILED 0x8100 /*
+ * PECI transaction failed for more
+ * than the configured number of
+ * consecutive retries.
+ */
+#define MAX6621_POOL_DIS 0x8101 /*
+ * Polling disabled for requested
+ * socket/domain.
+ */
+#define MAX6621_POOL_UNCOMPLETE 0x8102 /*
+ * First poll not yet completed for
+ * requested socket/domain (on
+ * startup).
+ */
+#define MAX6621_SD_DIS 0x8103 /*
+ * Read maximum temperature requested,
+ * but no sockets/domains enabled or
+ * all enabled sockets/domains have
+ * errors; or read maximum temperature
+ * address requested, but read maximum
+ * temperature was not called.
+ */
+#define MAX6621_ALERT_DIS 0x8104 /*
+ * Get alert socket/domain requested,
+ * but no alert active.
+ */
+#define MAX6621_PECI_ERR_MIN 0x8000 /* Intel spec PECI error min value. */
+#define MAX6621_PECI_ERR_MAX 0x80ff /* Intel spec PECI error max value. */
+
+static const u32 max6621_temp_regs[] = {
+ MAX6621_TEMP_MAX_REG, MAX6621_TEMP_S0D0_REG, MAX6621_TEMP_S1D0_REG,
+ MAX6621_TEMP_S2D0_REG, MAX6621_TEMP_S3D0_REG, MAX6621_TEMP_S0D1_REG,
+ MAX6621_TEMP_S1D1_REG, MAX6621_TEMP_S2D1_REG, MAX6621_TEMP_S3D1_REG,
+};
+
+static const char *const max6621_temp_labels[] = {
+ "maximum",
+ "socket0_0",
+ "socket1_0",
+ "socket2_0",
+ "socket3_0",
+ "socket0_1",
+ "socket1_1",
+ "socket2_1",
+ "socket3_1",
+};
+
+static const int max6621_temp_alert_chan2reg[] = {
+ MAX6621_CLEAR_ALERT_REG,
+ MAX6621_TEMP_S0_ALERT_REG,
+ MAX6621_TEMP_S1_ALERT_REG,
+ MAX6621_TEMP_S2_ALERT_REG,
+ MAX6621_TEMP_S3_ALERT_REG,
+};
+
+/**
+ * struct max6621_data - private data:
+ *
+ * @client: I2C client;
+ * @regmap: register map handle;
+ * @temp_offset: offset that is added to all temperature return;
+ * @input_chan2reg: mapping from channel to register;
+ */
+struct max6621_data {
+ struct i2c_client *client;
+ struct regmap *regmap;
+ u16 temp_offset;
+ int input_chan2reg[MAX6621_TEMP_INPUT_REG_NUM + 1];
+};
+
+static long max6621_temp_mc2reg(long val)
+{
+ return (val / 1000L) << MAX6621_REG_TEMP_SHIFT;
+}
+
+static umode_t
+max6621_is_visible(const void *data, enum hwmon_sensor_types type, u32 attr,
+ int channel)
+{
+ /* Skip channels which are not physically conncted. */
+ if (((struct max6621_data *)data)->input_chan2reg[channel] < 0)
+ return 0;
+
+ switch (type) {
+ case hwmon_temp:
+ switch (attr) {
+ case hwmon_temp_input:
+ return 0444;
+ case hwmon_temp_label:
+ case hwmon_temp_offset:
+ case hwmon_temp_crit:
+ case hwmon_temp_alarm:
+ return 0644;
+ default:
+ break;
+ }
+
+ default:
+ break;
+ }
+
+ return 0;
+}
+
+static int max6621_verify_reg_data(struct device *dev, int regval)
+{
+ if (regval >= MAX6621_PECI_ERR_MIN && regval <=
+ MAX6621_PECI_ERR_MAX) {
+ dev_dbg(dev, "PECI error code - err 0x%04x.\n",
+ regval);
+
+ return -EINVAL;
+ }
+
+ switch (regval) {
+ case MAX6621_TRAN_FAILED:
+ dev_dbg(dev, "PECI transaction failed - err 0x%04x.\n",
+ regval);
+ break;
+ case MAX6621_POOL_DIS:
+ dev_dbg(dev, "Polling disabled - err 0x%04x.\n", regval);
+ break;
+ case MAX6621_POOL_UNCOMPLETE:
+ dev_dbg(dev, "First poll not completed on startup - err 0x%04x.\n",
+ regval);
+ break;
+ case MAX6621_SD_DIS:
+ dev_dbg(dev, "Resource is disabled - err 0x%04x.\n", regval);
+ break;
+ case MAX6621_ALERT_DIS:
+ dev_dbg(dev, "No alert active - err 0x%04x.\n", regval);
+ break;
+ default:
+ return 0;
+ }
+
+ return -EINVAL;
+}
+
+static int
+max6621_read(struct device *dev, enum hwmon_sensor_types type, u32 attr,
+ int channel, long *val)
+{
+ struct max6621_data *data = dev_get_drvdata(dev);
+ u32 regval;
+ int reg;
+ s8 temp;
+ int ret;
+
+ switch (type) {
+ case hwmon_temp:
+ switch (attr) {
+ case hwmon_temp_input:
+ reg = data->input_chan2reg[channel];
+ ret = regmap_read(data->regmap, reg, ®val);
+ if (ret)
+ return ret;
+
+ ret = max6621_verify_reg_data(dev, regval);
+ if (ret)
+ return ret;
+
+ temp = (regval >> MAX6621_REG_TEMP_SHIFT);
+ *val = temp * 1000L;
+
+ break;
+ case hwmon_temp_offset:
+ *val = (data->temp_offset >> MAX6621_REG_TEMP_SHIFT) *
+ 1000L;
+
+ break;
+ case hwmon_temp_crit:
+ reg = max6621_temp_alert_chan2reg[channel];
+ ret = regmap_read(data->regmap, reg, ®val);
+ if (ret)
+ return ret;
+
+ ret = max6621_verify_reg_data(dev, regval);
+ if (ret)
+ return ret;
+
+ *val = regval * 1000L;
+
+ break;
+ case hwmon_temp_alarm:
+ ret = regmap_read(data->regmap,
+ MAX6621_TEMP_ALERT_CAUSE,
+ ®val);
+ if (ret)
+ return ret;
+
+ ret = max6621_verify_reg_data(dev, regval);
+ if (ret < 0)
+ return ret;
+
+ *val = !!regval;
+
+ break;
+ default:
+ return -EOPNOTSUPP;
+ }
+ break;
+
+ default:
+ return -EOPNOTSUPP;
+ }
+
+ return 0;
+}
+
+static int
+max6621_write(struct device *dev, enum hwmon_sensor_types type, u32 attr,
+ int channel, long val)
+{
+ struct max6621_data *data = dev_get_drvdata(dev);
+ u32 reg;
+
+ switch (type) {
+ case hwmon_temp:
+ switch (attr) {
+ case hwmon_temp_offset:
+ /* Clamp to allowed range to prevent overflow. */
+ val = clamp_val(val, MAX6621_TEMP_INPUT_MIN,
+ MAX6621_TEMP_INPUT_MAX);
+ val = max6621_temp_mc2reg(val);
+ if (data->temp_offset != val) {
+ data->temp_offset = val;
+ return regmap_write(data->regmap,
+ MAX6621_CONFIG2_REG, val);
+ }
+
+ return 0;
+ case hwmon_temp_crit:
+ reg = max6621_temp_alert_chan2reg[channel];
+ /* Clamp to allowed range to prevent overflow. */
+ val = clamp_val(val, MAX6621_TEMP_INPUT_MIN,
+ MAX6621_TEMP_INPUT_MAX);
+ val = val / 1000L;
+
+ return regmap_write(data->regmap, reg, val);
+ case hwmon_temp_alarm:
+ /*
+ * Use i2c_smbus_write_byte, since
+ * MAX6621_CLEAR_ALERT_REG access expects send-byte
+ * smbus protocol for clearing alert.
+ */
+ return i2c_smbus_write_byte(data->client,
+ MAX6621_CLEAR_ALERT_REG);
+ default:
+ return -EOPNOTSUPP;
+ }
+ break;
+
+ default:
+ return -EOPNOTSUPP;
+ }
+
+ return -EOPNOTSUPP;
+}
+
+static int
+max6621_read_string(struct device *dev, enum hwmon_sensor_types type, u32 attr,
+ int channel, const char **str)
+{
+ switch (type) {
+ case hwmon_temp:
+ switch (attr) {
+ case hwmon_temp_label:
+ *str = max6621_temp_labels[channel];
+ return 0;
+ default:
+ return -EOPNOTSUPP;
+ }
+ break;
+ default:
+ return -EOPNOTSUPP;
+ }
+
+ return -EOPNOTSUPP;
+}
+
+static const struct regmap_config max6621_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 16,
+ .max_register = MAX6621_REG_MAX,
+ .val_format_endian = REGMAP_ENDIAN_LITTLE,
+};
+
+static u32 max6621_chip_config[] = {
+ HWMON_C_REGISTER_TZ,
+ 0
+};
+
+static const struct hwmon_channel_info max6621_chip = {
+ .type = hwmon_chip,
+ .config = max6621_chip_config,
+};
+
+static const u32 max6621_temp_config[] = {
+ HWMON_T_INPUT | HWMON_T_ALARM | HWMON_T_LABEL | HWMON_T_OFFSET,
+ HWMON_T_INPUT | HWMON_T_CRIT | HWMON_T_LABEL,
+ HWMON_T_INPUT | HWMON_T_CRIT | HWMON_T_LABEL,
+ HWMON_T_INPUT | HWMON_T_CRIT | HWMON_T_LABEL,
+ HWMON_T_INPUT | HWMON_T_CRIT,
+ HWMON_T_INPUT | HWMON_T_LABEL,
+ HWMON_T_INPUT | HWMON_T_LABEL,
+ HWMON_T_INPUT | HWMON_T_LABEL,
+ HWMON_T_INPUT | HWMON_T_LABEL,
+ 0
+};
+
+static const struct hwmon_channel_info max6621_temp = {
+ .type = hwmon_temp,
+ .config = max6621_temp_config,
+};
+
+static const struct hwmon_channel_info *max6621_info[] = {
+ &max6621_chip,
+ &max6621_temp,
+ NULL
+};
+
+static const struct hwmon_ops max6621_hwmon_ops = {
+ .read = max6621_read,
+ .write = max6621_write,
+ .read_string = max6621_read_string,
+ .is_visible = max6621_is_visible,
+};
+
+static const struct hwmon_chip_info max6621_chip_info = {
+ .ops = &max6621_hwmon_ops,
+ .info = max6621_info,
+};
+
+static int max6621_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct device *dev = &client->dev;
+ struct max6621_data *data;
+ struct device *hwmon_dev;
+ int i;
+ int ret;
+
+ data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ data->regmap = devm_regmap_init_i2c(client, &max6621_regmap_config);
+ if (IS_ERR(data->regmap))
+ return PTR_ERR(data->regmap);
+
+ i2c_set_clientdata(client, data);
+ data->client = client;
+
+ /* Set CONFIG0 register masking temperature alerts and PEC. */
+ ret = regmap_write(data->regmap, MAX6621_CONFIG0_REG,
+ MAX6621_CONFIG0_INIT);
+ if (ret)
+ return ret;
+
+ /* Verify which temperature input registers are enabled. */
+ for (i = 0; i < MAX6621_TEMP_INPUT_REG_NUM; i++) {
+ ret = i2c_smbus_read_word_data(client, max6621_temp_regs[i]);
+ if (ret < 0)
+ return ret;
+ ret = max6621_verify_reg_data(dev, ret);
+ if (ret) {
+ data->input_chan2reg[i] = -1;
+ continue;
+ }
+
+ data->input_chan2reg[i] = max6621_temp_regs[i];
+ }
+
+ hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
+ data,
+ &max6621_chip_info,
+ NULL);
+
+ return PTR_ERR_OR_ZERO(hwmon_dev);
+}
+
+static const struct i2c_device_id max6621_id[] = {
+ { MAX6621_DRV_NAME, 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, max6621_id);
+
+static const struct of_device_id max6621_of_match[] = {
+ { .compatible = "maxim,max6621" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, max6621_of_match);
+
+static struct i2c_driver max6621_driver = {
+ .class = I2C_CLASS_HWMON,
+ .driver = {
+ .name = MAX6621_DRV_NAME,
+ .of_match_table = of_match_ptr(max6621_of_match),
+ },
+ .probe = max6621_probe,
+ .id_table = max6621_id,
+};
+
+module_i2c_driver(max6621_driver);
+
+MODULE_AUTHOR("Vadim Pasternak <vadimp@xxxxxxxxxxxx>");
+MODULE_DESCRIPTION("Driver for Maxim MAX6621");
+MODULE_LICENSE("GPL");
--
2.1.4
--
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