On Tue, Aug 29, 2017 at 08:46:48PM +0000, Vadim Pasternak wrote:
> 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 <[email protected]>
> ---
> drivers/hwmon/Kconfig | 14 ++
> drivers/hwmon/Makefile | 1 +
> drivers/hwmon/max6621.c | 531
> ++++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 546 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..5fba162
> --- /dev/null
> +++ b/drivers/hwmon/max6621.c
> @@ -0,0 +1,531 @@
> +/*
> + * Hardware monitoring driver for Naxim MAX6621
> + *
> + * Copyright (c) 2017 Mellanox Technologies. All rights reserved.
> + * Copyright (c) 2017 Vadim Pasternak <[email protected]>
> + *
> + * 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/module.h>
> +#include <linux/init.h>
> +#include <linux/slab.h>
> +#include <linux/i2c.h>
> +#include <linux/hwmon.h>
> +#include <linux/hwmon-sysfs.h>
> +#include <linux/of_device.h>
> +#include <linux/of.h>
> +#include <linux/regmap.h>
Alphabetic order, please.
> +
> +#define MAX6621_DRV_NAME "max6621"
> +#define MAX6621_CHAN_NOT_CONNECTED -255
> +#define MAX6621_TEMP_INPUT_REG_NUM 9
> +#define MAX6621_TEMP_INPUT_MIN -20
> +#define MAX6621_TEMP_INPUT_MAX 120
> +
> +#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_TEMP_ACTIVATION_POINT 0x1a40 /* 2's complement of 105
> Cel */
> +
> +#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)
requires include of bitops.h.
> +#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. */
> +
> +#define MAX6621_REG_NON_WRITEABLE_REG (MAX6621_TEMP_S0D0_REG | \
> + MAX6621_TEMP_S0D1_REG | \
> + MAX6621_TEMP_S1D0_REG | \
> + MAX6621_TEMP_S1D1_REG | \
> + MAX6621_TEMP_S2D0_REG | \
> + MAX6621_TEMP_S2D1_REG | \
> + MAX6621_TEMP_S3D0_REG | \
> + MAX6621_TEMP_S3D1_REG | \
> + MAX6621_TEMP_MAX_REG | \
> + MAX6621_TEMP_MAX_ADDR_REG)
This logical or of registers doesn't make sense to me.
> +
> +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_domain0",
> + "socket0_domain1",
> + "socket1_domain0",
> + "socket1_domain1",
> + "socket2_domain0",
> + "socket2_domain1",
> + "socket3_domain0",
> + "socket3_domain1",
Are those labels really useful ?
> +};
> +
> +static const int max6621_temp_alert_chan2reg[] = {
> + MAX6621_CLEAR_ALERT_REG,
> + MAX6621_TEMP_S0_ALERT_REG,
> + MAX6621_TEMP_S0_ALERT_REG,
> + MAX6621_TEMP_S1_ALERT_REG,
> + MAX6621_TEMP_S1_ALERT_REG,
> + MAX6621_TEMP_S2_ALERT_REG,
> + MAX6621_TEMP_S2_ALERT_REG,
> + MAX6621_TEMP_S3_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;
> + * @temp_min: minimum temperature value;
> + * @temp_max: maximum temperature value;
> + * @temp_reset_history: clear alert counter;
> + * @input_chan2reg: mapping from channel to register;
> + */
> +struct max6621_data {
> + struct i2c_client *client;
> + struct regmap *regmap;
> + u16 temp_offset;
> + int temp_min;
> + int temp_max;
> + u32 temp_reset_history;
limit attributes are only supposed to be provided if the chip supports it.
Resetting the history only makes sense if the chip actually keeps a history.
Please drop.
> + int input_chan2reg[MAX6621_TEMP_INPUT_REG_NUM + 1];
> +};
> +
> +static umode_t
> +max6621_is_visible(const void *data, enum hwmon_sensor_types type, u32 attr,
> + int channel)
> +{
> + switch (type) {
> + case hwmon_temp:
> + switch (attr) {
> + case hwmon_temp_input:
> + case hwmon_temp_min:
> + case hwmon_temp_max:
> + return 0444;
> + case hwmon_temp_label:
> + case hwmon_temp_offset:
> + return 0644;
> + case hwmon_temp_fault:
> + return 0644;
> + default:
> + break;
> + }
> + case hwmon_chip:
> + switch (attr) {
> + case hwmon_chip_temp_reset_history:
> + 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)) {
Please no unnecessary ( ).
> + 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);
> + return -EINVAL;
> + 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);
> + return -EINVAL;
> + 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 regval;
This can return MAX6621_POOL_DIS, MAX6621_SD_DIS, or MAX6621_ALERT_DIS,
all of which are interpreted as errors but not negative. Are you sure this
is what you want ?
> +}
> +
> +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);
> + int regval, reg;
> + s8 temp;
> + int ret;
> +
> + switch (type) {
> + case hwmon_temp:
> + switch (attr) {
> + case hwmon_temp_input:
> + reg = data->input_chan2reg[channel];
> + if (reg < 0) {
> + /* channel is not connected */
> + *val = MAX6621_CHAN_NOT_CONNECTED;
Odd value to return. -0.255 degrees C ? Wouldn't it be better to not report
those channels at all ?
> + return 0;
> + }
> +
> + ret = regmap_read(data->regmap, reg, ®val);
regval is int, regmap_read() expects unsigned int.
> + if (ret)
> + return ret;
> + ret = max6621_verify_reg_data(dev, regval);
> + if (ret)
> + return ret;
> +
> + temp = (regval >> MAX6621_REG_TEMP_SHIFT);
> + *val = temp * 1000;
> + break;
> + case hwmon_temp_offset:
> + *val = data->temp_offset >> MAX6621_REG_TEMP_SHIFT;
Is that correct ? The temperature offset is supposed to be in milli-degrees C.
> + break;
> + case hwmon_temp_min:
> + *val = data->temp_min;
> + break;
> + case hwmon_temp_max:
> + *val = data->temp_max;
> + break;
> + case hwmon_temp_fault:
> + /* If channel is 0 - read alert cause reg. */
> + if (!channel)
> + reg = MAX6621_TEMP_ALERT_CAUSE;
> + else
> + reg = max6621_temp_alert_chan2reg[channel];
This is odd. The attribute is supposed to return 1 if there is a fault,
0 otherwise. Yet, you are using the attribute to report an actual temperature
unless I misunderstand the datasheet.
If anything, the alert temperatures should be reported (and set) as
tempX_max or tempX_crit, but not as fault flags.
Also, "fault" refers to a fault, ie chip failure, not to a high temperature
alarm. What you are looking for is tempX_max_alarm or tempX_crit_alarm,
not tempX_fault. Again, those are booleans, not values.
> + ret = regmap_read(data->regmap, reg, ®val);
> + if (ret)
> + return ret;
> + ret = max6621_verify_reg_data(dev, regval);
> + if (ret < 0)
> + return ret;
> +
> + *val = regval;
> + break;
> + default:
> + return -EOPNOTSUPP;
> + }
> + break;
> +
> + case hwmon_chip:
> + switch (attr) {
> + case hwmon_chip_temp_reset_history:
> + *val = data->temp_reset_history;
This is supposed to be written to reset the history. The chip does not support
history registers, so please drop.
> + 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);
> + int reg;
> +
> + switch (type) {
> + case hwmon_temp:
> + switch (attr) {
> + case hwmon_temp_offset:
> + val <<= MAX6621_REG_TEMP_SHIFT;
Same problem as before; this is supposed to be written in milli-degrees C.
Also, you'll have to make sure that writes don't overflow.
> + if (data->temp_offset != val) {
> + data->temp_offset = val;
> + return regmap_write(data->regmap,
> + MAX6621_CONFIG2_REG, val);
> + }
> + return 0;
> + case hwmon_temp_fault:
> + reg = max6621_temp_alert_chan2reg[channel];
> + if (reg == MAX6621_CLEAR_ALERT_REG) {
> + data->temp_reset_history++;
This is not a proper use of the reset_history attribute.
> + return i2c_smbus_write_byte(data->client, reg);
How is this different to the regmap_write below ?
> + }
> + return regmap_write(data->regmap, reg, val);
> + case hwmon_temp_min:
> + data->temp_min = val;
> + return 0;
> + case hwmon_temp_max:
> + data->temp_max = val;
> + return 0;
> + default:
> + return -EOPNOTSUPP;
> + }
> + break;
> + case hwmon_chip:
> + switch (attr) {
> + case hwmon_chip_temp_reset_history:
> + data->temp_reset_history = val;
> + return 0;
> + 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_TEMP_RESET_HISTORY | 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_MIN | HWMON_T_MAX | HWMON_T_FAULT |
> + HWMON_T_LABEL | HWMON_T_OFFSET,
> + HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX | HWMON_T_FAULT |
> + HWMON_T_LABEL,
> + HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX | HWMON_T_FAULT |
> + HWMON_T_LABEL,
> + HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX | HWMON_T_FAULT |
> + HWMON_T_LABEL,
> + HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX | HWMON_T_FAULT |
> + HWMON_T_LABEL,
> + HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX | HWMON_T_FAULT |
> + HWMON_T_LABEL,
> + HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX | HWMON_T_FAULT |
> + HWMON_T_LABEL,
> + HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX | HWMON_T_FAULT |
> + HWMON_T_LABEL,
> + HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX | HWMON_T_FAULT |
> + 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;
> +
> + /* Set CONFIG2 register to activation point. */
> + data->temp_offset = MAX6621_TEMP_ACTIVATION_POINT;
Isn't that a bit random ? I think it should be better left to user space
to initialize this register.
> + ret = regmap_write(data->regmap, MAX6621_CONFIG2_REG,
> + data->temp_offset);
> + 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];
> + }
> +
> + data->temp_min = MAX6621_TEMP_INPUT_MIN;
> + data->temp_max = MAX6621_TEMP_INPUT_MAX;
> +
> + 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 <[email protected]>");
> +MODULE_DESCRIPTION("Driver for Maxim MAX6621");
> +MODULE_LICENSE("GPL");
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