diff options
Diffstat (limited to 'drivers/hwmon/max6621.c')
| -rw-r--r-- | drivers/hwmon/max6621.c | 565 |
1 files changed, 565 insertions, 0 deletions
diff --git a/drivers/hwmon/max6621.c b/drivers/hwmon/max6621.c new file mode 100644 index 0000000000..af7e626858 --- /dev/null +++ b/drivers/hwmon/max6621.c @@ -0,0 +1,565 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Hardware monitoring driver for Maxim MAX6621 + * + * Copyright (c) 2017 Mellanox Technologies. All rights reserved. + * Copyright (c) 2017 Vadim Pasternak <vadimp@mellanox.com> + */ + +#include <linux/bitops.h> +#include <linux/hwmon.h> +#include <linux/hwmon-sysfs.h> +#include <linux/i2c.h> +#include <linux/init.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/regmap.h> + +#define MAX6621_DRV_NAME "max6621" +#define MAX6621_TEMP_INPUT_REG_NUM 9 +#define MAX6621_TEMP_INPUT_MIN -127000 +#define MAX6621_TEMP_INPUT_MAX 128000 +#define MAX6621_TEMP_ALERT_CHAN_SHIFT 1 + +#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_MAX_ADDR_REG 0x0a +#define MAX6621_TEMP_ALERT_CAUSE_REG 0x0b +#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_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) +#define MAX6621_PECI_BIT_TIME 0x2 +#define MAX6621_PECI_RETRY_NUM 0x3 +#define MAX6621_CONFIG1_INIT ((MAX6621_PECI_BIT_TIME << 8) | \ + MAX6621_PECI_RETRY_NUM) + +/* 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_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; + * @input_chan2reg: mapping from channel to register; + */ +struct max6621_data { + struct i2c_client *client; + struct regmap *regmap; + 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: + case hwmon_temp_label: + case hwmon_temp_crit_alarm: + return 0444; + case hwmon_temp_offset: + case hwmon_temp_crit: + return 0644; + default: + break; + } + 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 -EIO; + } + + switch (regval) { + case MAX6621_TRAN_FAILED: + dev_dbg(dev, "PECI transaction failed - err 0x%04x.\n", + regval); + return -EIO; + case MAX6621_POOL_DIS: + dev_dbg(dev, "Polling disabled - err 0x%04x.\n", regval); + return -EOPNOTSUPP; + case MAX6621_POOL_UNCOMPLETE: + dev_dbg(dev, "First poll not completed on startup - err 0x%04x.\n", + regval); + return -EIO; + case MAX6621_SD_DIS: + dev_dbg(dev, "Resource is disabled - err 0x%04x.\n", regval); + return -EOPNOTSUPP; + case MAX6621_ALERT_DIS: + dev_dbg(dev, "No alert active - err 0x%04x.\n", regval); + return -EOPNOTSUPP; + default: + return 0; + } +} + +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; + + /* + * Bit MAX6621_REG_TEMP_SHIFT represents 1 degree step. + * The temperature is given in two's complement and 8 + * bits is used for the register conversion. + */ + temp = (regval >> MAX6621_REG_TEMP_SHIFT); + *val = temp * 1000L; + + break; + case hwmon_temp_offset: + ret = regmap_read(data->regmap, MAX6621_CONFIG2_REG, + ®val); + if (ret) + return ret; + + ret = max6621_verify_reg_data(dev, regval); + if (ret) + return ret; + + *val = (regval >> MAX6621_REG_TEMP_SHIFT) * + 1000L; + + break; + case hwmon_temp_crit: + channel -= MAX6621_TEMP_ALERT_CHAN_SHIFT; + 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_crit_alarm: + /* + * Set val to zero to recover the case, when reading + * MAX6621_TEMP_ALERT_CAUSE_REG results in for example + * MAX6621_ALERT_DIS. Reading will return with error, + * but in such case alarm should be returned as 0. + */ + *val = 0; + ret = regmap_read(data->regmap, + MAX6621_TEMP_ALERT_CAUSE_REG, + ®val); + if (ret) + return ret; + + ret = max6621_verify_reg_data(dev, regval); + if (ret) { + /* Do not report error if alert is disabled. */ + if (regval == MAX6621_ALERT_DIS) + return 0; + else + return ret; + } + + /* + * Clear the alert automatically, using send-byte + * smbus protocol for clearing alert. + */ + if (regval) { + ret = i2c_smbus_write_byte(data->client, + MAX6621_CLEAR_ALERT_REG); + if (ret) + 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); + + return regmap_write(data->regmap, + MAX6621_CONFIG2_REG, val); + case hwmon_temp_crit: + channel -= MAX6621_TEMP_ALERT_CHAN_SHIFT; + 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); + 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 bool max6621_writeable_reg(struct device *dev, unsigned int reg) +{ + switch (reg) { + case MAX6621_CONFIG0_REG: + case MAX6621_CONFIG1_REG: + case MAX6621_CONFIG2_REG: + case MAX6621_CONFIG3_REG: + case MAX6621_TEMP_S0_ALERT_REG: + case MAX6621_TEMP_S1_ALERT_REG: + case MAX6621_TEMP_S2_ALERT_REG: + case MAX6621_TEMP_S3_ALERT_REG: + case MAX6621_TEMP_ALERT_CAUSE_REG: + return true; + } + return false; +} + +static bool max6621_readable_reg(struct device *dev, unsigned int reg) +{ + switch (reg) { + case MAX6621_TEMP_S0D0_REG: + case MAX6621_TEMP_S0D1_REG: + case MAX6621_TEMP_S1D0_REG: + case MAX6621_TEMP_S1D1_REG: + case MAX6621_TEMP_S2D0_REG: + case MAX6621_TEMP_S2D1_REG: + case MAX6621_TEMP_S3D0_REG: + case MAX6621_TEMP_S3D1_REG: + case MAX6621_TEMP_MAX_REG: + case MAX6621_TEMP_MAX_ADDR_REG: + case MAX6621_CONFIG0_REG: + case MAX6621_CONFIG1_REG: + case MAX6621_CONFIG2_REG: + case MAX6621_CONFIG3_REG: + case MAX6621_TEMP_S0_ALERT_REG: + case MAX6621_TEMP_S1_ALERT_REG: + case MAX6621_TEMP_S2_ALERT_REG: + case MAX6621_TEMP_S3_ALERT_REG: + return true; + } + return false; +} + +static bool max6621_volatile_reg(struct device *dev, unsigned int reg) +{ + switch (reg) { + case MAX6621_TEMP_S0D0_REG: + case MAX6621_TEMP_S0D1_REG: + case MAX6621_TEMP_S1D0_REG: + case MAX6621_TEMP_S1D1_REG: + case MAX6621_TEMP_S2D0_REG: + case MAX6621_TEMP_S2D1_REG: + case MAX6621_TEMP_S3D0_REG: + case MAX6621_TEMP_S3D1_REG: + case MAX6621_TEMP_MAX_REG: + case MAX6621_TEMP_S0_ALERT_REG: + case MAX6621_TEMP_S1_ALERT_REG: + case MAX6621_TEMP_S2_ALERT_REG: + case MAX6621_TEMP_S3_ALERT_REG: + case MAX6621_TEMP_ALERT_CAUSE_REG: + return true; + } + return false; +} + +static const struct reg_default max6621_regmap_default[] = { + { MAX6621_CONFIG0_REG, MAX6621_CONFIG0_INIT }, + { MAX6621_CONFIG1_REG, MAX6621_CONFIG1_INIT }, +}; + +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, + .cache_type = REGCACHE_FLAT, + .writeable_reg = max6621_writeable_reg, + .readable_reg = max6621_readable_reg, + .volatile_reg = max6621_volatile_reg, + .reg_defaults = max6621_regmap_default, + .num_reg_defaults = ARRAY_SIZE(max6621_regmap_default), +}; + +static const struct hwmon_channel_info * const max6621_info[] = { + HWMON_CHANNEL_INFO(chip, + HWMON_C_REGISTER_TZ), + HWMON_CHANNEL_INFO(temp, + HWMON_T_INPUT | HWMON_T_LABEL | HWMON_T_OFFSET, + HWMON_T_INPUT | HWMON_T_CRIT | HWMON_T_CRIT_ALARM | HWMON_T_LABEL, + HWMON_T_INPUT | HWMON_T_CRIT | HWMON_T_CRIT_ALARM | HWMON_T_LABEL, + HWMON_T_INPUT | HWMON_T_CRIT | HWMON_T_CRIT_ALARM | HWMON_T_LABEL, + HWMON_T_INPUT | HWMON_T_CRIT | HWMON_T_CRIT_ALARM | HWMON_T_LABEL, + HWMON_T_INPUT | HWMON_T_LABEL, + HWMON_T_INPUT | HWMON_T_LABEL, + HWMON_T_INPUT | HWMON_T_LABEL, + HWMON_T_INPUT | HWMON_T_LABEL), + 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) +{ + 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 CONFIG1 register for PEC access retry number. */ + ret = regmap_write(data->regmap, MAX6621_CONFIG1_REG, + MAX6621_CONFIG1_INIT); + if (ret) + return ret; + + /* Sync registers with hardware. */ + regcache_mark_dirty(data->regmap); + ret = regcache_sync(data->regmap); + 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 __maybe_unused 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@mellanox.com>"); +MODULE_DESCRIPTION("Driver for Maxim MAX6621"); +MODULE_LICENSE("GPL"); |