diff options
Diffstat (limited to 'drivers/hwmon/stts751.c')
| -rw-r--r-- | drivers/hwmon/stts751.c | 834 |
1 files changed, 834 insertions, 0 deletions
diff --git a/drivers/hwmon/stts751.c b/drivers/hwmon/stts751.c new file mode 100644 index 000000000000..55450680fb58 --- /dev/null +++ b/drivers/hwmon/stts751.c @@ -0,0 +1,834 @@ +/* + * STTS751 sensor driver + * + * Copyright (C) 2016-2017 Istituto Italiano di Tecnologia - RBCS - EDL + * Robotics, Brain and Cognitive Sciences department + * Electronic Design Laboratory + * + * Written by Andrea Merello <andrea.merello@gmail.com> + * + * Based on LM95241 driver and LM90 driver + * + * 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/err.h> +#include <linux/hwmon.h> +#include <linux/hwmon-sysfs.h> +#include <linux/i2c.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/jiffies.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/property.h> +#include <linux/slab.h> +#include <linux/sysfs.h> +#include <linux/util_macros.h> + +#define DEVNAME "stts751" + +static const unsigned short normal_i2c[] = { + 0x48, 0x49, 0x38, 0x39, /* STTS751-0 */ + 0x4A, 0x4B, 0x3A, 0x3B, /* STTS751-1 */ + I2C_CLIENT_END }; + +#define STTS751_REG_TEMP_H 0x00 +#define STTS751_REG_STATUS 0x01 +#define STTS751_STATUS_TRIPT BIT(0) +#define STTS751_STATUS_TRIPL BIT(5) +#define STTS751_STATUS_TRIPH BIT(6) +#define STTS751_REG_TEMP_L 0x02 +#define STTS751_REG_CONF 0x03 +#define STTS751_CONF_RES_MASK 0x0C +#define STTS751_CONF_RES_SHIFT 2 +#define STTS751_CONF_EVENT_DIS BIT(7) +#define STTS751_CONF_STOP BIT(6) +#define STTS751_REG_RATE 0x04 +#define STTS751_REG_HLIM_H 0x05 +#define STTS751_REG_HLIM_L 0x06 +#define STTS751_REG_LLIM_H 0x07 +#define STTS751_REG_LLIM_L 0x08 +#define STTS751_REG_TLIM 0x20 +#define STTS751_REG_HYST 0x21 +#define STTS751_REG_SMBUS_TO 0x22 + +#define STTS751_REG_PROD_ID 0xFD +#define STTS751_REG_MAN_ID 0xFE +#define STTS751_REG_REV_ID 0xFF + +#define STTS751_0_PROD_ID 0x00 +#define STTS751_1_PROD_ID 0x01 +#define ST_MAN_ID 0x53 + +/* + * Possible update intervals are (in mS): + * 16000, 8000, 4000, 2000, 1000, 500, 250, 125, 62.5, 31.25 + * However we are not going to complicate things too much and we stick to the + * approx value in mS. + */ +static const int stts751_intervals[] = { + 16000, 8000, 4000, 2000, 1000, 500, 250, 125, 63, 31 +}; + +static const struct i2c_device_id stts751_id[] = { + { "stts751", 0 }, + { } +}; + +struct stts751_priv { + struct device *dev; + struct i2c_client *client; + struct mutex access_lock; + u8 interval; + int res; + int event_max, event_min; + int therm; + int hyst; + bool smbus_timeout; + int temp; + unsigned long last_update, last_alert_update; + u8 config; + bool min_alert, max_alert, therm_trip; + bool data_valid, alert_valid; + bool notify_max, notify_min; +}; + +/* + * These functions converts temperature from HW format to integer format and + * vice-vers. They are (mostly) taken from lm90 driver. Unit is in mC. + */ +static int stts751_to_deg(s16 hw_val) +{ + return hw_val * 125 / 32; +} + +static s32 stts751_to_hw(int val) +{ + return DIV_ROUND_CLOSEST(val, 125) * 32; +} + +static int stts751_adjust_resolution(struct stts751_priv *priv) +{ + u8 res; + + switch (priv->interval) { + case 9: + /* 10 bits */ + res = 0; + break; + case 8: + /* 11 bits */ + res = 1; + break; + default: + /* 12 bits */ + res = 3; + break; + } + + if (priv->res == res) + return 0; + + priv->config &= ~STTS751_CONF_RES_MASK; + priv->config |= res << STTS751_CONF_RES_SHIFT; + dev_dbg(&priv->client->dev, "setting res %d. config %x", + res, priv->config); + priv->res = res; + + return i2c_smbus_write_byte_data(priv->client, + STTS751_REG_CONF, priv->config); +} + +static int stts751_update_temp(struct stts751_priv *priv) +{ + s32 integer1, integer2, frac; + + /* + * There is a trick here, like in the lm90 driver. We have to read two + * registers to get the sensor temperature, but we have to beware a + * conversion could occur between the readings. We could use the + * one-shot conversion register, but we don't want to do this (disables + * hardware monitoring). So the solution used here is to read the high + * byte once, then the low byte, then the high byte again. If the new + * high byte matches the old one, then we have a valid reading. Else we + * have to read the low byte again, and now we believe we have a correct + * reading. + */ + integer1 = i2c_smbus_read_byte_data(priv->client, STTS751_REG_TEMP_H); + if (integer1 < 0) { + dev_dbg(&priv->client->dev, + "I2C read failed (temp H). ret: %x\n", integer1); + return integer1; + } + + frac = i2c_smbus_read_byte_data(priv->client, STTS751_REG_TEMP_L); + if (frac < 0) { + dev_dbg(&priv->client->dev, + "I2C read failed (temp L). ret: %x\n", frac); + return frac; + } + + integer2 = i2c_smbus_read_byte_data(priv->client, STTS751_REG_TEMP_H); + if (integer2 < 0) { + dev_dbg(&priv->client->dev, + "I2C 2nd read failed (temp H). ret: %x\n", integer2); + return integer2; + } + + if (integer1 != integer2) { + frac = i2c_smbus_read_byte_data(priv->client, + STTS751_REG_TEMP_L); + if (frac < 0) { + dev_dbg(&priv->client->dev, + "I2C 2nd read failed (temp L). ret: %x\n", + frac); + return frac; + } + } + + priv->temp = stts751_to_deg((integer1 << 8) | frac); + return 0; +} + +static int stts751_set_temp_reg16(struct stts751_priv *priv, int temp, + u8 hreg, u8 lreg) +{ + s32 hwval; + int ret; + + hwval = stts751_to_hw(temp); + + ret = i2c_smbus_write_byte_data(priv->client, hreg, hwval >> 8); + if (ret) + return ret; + + return i2c_smbus_write_byte_data(priv->client, lreg, hwval & 0xff); +} + +static int stts751_set_temp_reg8(struct stts751_priv *priv, int temp, u8 reg) +{ + s32 hwval; + + hwval = stts751_to_hw(temp); + return i2c_smbus_write_byte_data(priv->client, reg, hwval >> 8); +} + +static int stts751_read_reg16(struct stts751_priv *priv, int *temp, + u8 hreg, u8 lreg) +{ + int integer, frac; + + integer = i2c_smbus_read_byte_data(priv->client, hreg); + if (integer < 0) + return integer; + + frac = i2c_smbus_read_byte_data(priv->client, lreg); + if (frac < 0) + return frac; + + *temp = stts751_to_deg((integer << 8) | frac); + + return 0; +} + +static int stts751_read_reg8(struct stts751_priv *priv, int *temp, u8 reg) +{ + int integer; + + integer = i2c_smbus_read_byte_data(priv->client, reg); + if (integer < 0) + return integer; + + *temp = stts751_to_deg(integer << 8); + + return 0; +} + +/* + * Update alert flags without waiting for cache to expire. We detects alerts + * immediately for the sake of the alert handler; we still need to deal with + * caching to workaround the fact that alarm flags int the status register, + * despite what the datasheet claims, gets always cleared on read. + */ +static int stts751_update_alert(struct stts751_priv *priv) +{ + int ret; + bool conv_done; + int cache_time = msecs_to_jiffies(stts751_intervals[priv->interval]); + + /* + * Add another 10% because if we run faster than the HW conversion + * rate we will end up in reporting incorrectly alarms. + */ + cache_time += cache_time / 10; + + ret = i2c_smbus_read_byte_data(priv->client, STTS751_REG_STATUS); + if (ret < 0) + return ret; + + dev_dbg(&priv->client->dev, "status reg %x\n", ret); + conv_done = ret & (STTS751_STATUS_TRIPH | STTS751_STATUS_TRIPL); + /* + * Reset the cache if the cache time expired, or if we are sure + * we have valid data from a device conversion, or if we know + * our cache has been never written. + * + * Note that when the cache has been never written the point is + * to correctly initialize the timestamp, rather than clearing + * the cache values. + * + * Note that updating the cache timestamp when we get an alarm flag + * is required, otherwise we could incorrectly report alarms to be zero. + */ + if (time_after(jiffies, priv->last_alert_update + cache_time) || + conv_done || !priv->alert_valid) { + priv->max_alert = false; + priv->min_alert = false; + priv->alert_valid = true; + priv->last_alert_update = jiffies; + dev_dbg(&priv->client->dev, "invalidating alert cache\n"); + } + + priv->max_alert |= !!(ret & STTS751_STATUS_TRIPH); + priv->min_alert |= !!(ret & STTS751_STATUS_TRIPL); + priv->therm_trip = !!(ret & STTS751_STATUS_TRIPT); + + dev_dbg(&priv->client->dev, "max_alert: %d, min_alert: %d, therm_trip: %d\n", + priv->max_alert, priv->min_alert, priv->therm_trip); + + return 0; +} + +static void stts751_alert(struct i2c_client *client, + enum i2c_alert_protocol type, unsigned int data) +{ + int ret; + struct stts751_priv *priv = i2c_get_clientdata(client); + + if (type != I2C_PROTOCOL_SMBUS_ALERT) + return; + + dev_dbg(&client->dev, "alert!"); + + mutex_lock(&priv->access_lock); + ret = stts751_update_alert(priv); + if (ret < 0) { + /* default to worst case */ + priv->max_alert = true; + priv->min_alert = true; + + dev_warn(priv->dev, + "Alert received, but can't communicate to the device. Triggering all alarms!"); + } + + if (priv->max_alert) { + if (priv->notify_max) + dev_notice(priv->dev, "got alert for HIGH temperature"); + priv->notify_max = false; + + /* unblock alert poll */ + sysfs_notify(&priv->dev->kobj, NULL, "temp1_max_alarm"); + } + + if (priv->min_alert) { + if (priv->notify_min) + dev_notice(priv->dev, "got alert for LOW temperature"); + priv->notify_min = false; + + /* unblock alert poll */ + sysfs_notify(&priv->dev->kobj, NULL, "temp1_min_alarm"); + } + + if (priv->min_alert || priv->max_alert) + kobject_uevent(&priv->dev->kobj, KOBJ_CHANGE); + + mutex_unlock(&priv->access_lock); +} + +static int stts751_update(struct stts751_priv *priv) +{ + int ret; + int cache_time = msecs_to_jiffies(stts751_intervals[priv->interval]); + + if (time_after(jiffies, priv->last_update + cache_time) || + !priv->data_valid) { + ret = stts751_update_temp(priv); + if (ret) + return ret; + + ret = stts751_update_alert(priv); + if (ret) + return ret; + priv->data_valid = true; + priv->last_update = jiffies; + } + + return 0; +} + +static ssize_t show_max_alarm(struct device *dev, struct device_attribute *attr, + char *buf) +{ + int ret; + struct stts751_priv *priv = dev_get_drvdata(dev); + + mutex_lock(&priv->access_lock); + ret = stts751_update(priv); + if (!ret) + priv->notify_max = true; + mutex_unlock(&priv->access_lock); + if (ret < 0) + return ret; + + return snprintf(buf, PAGE_SIZE - 1, "%d\n", priv->max_alert); +} + +static ssize_t show_min_alarm(struct device *dev, struct device_attribute *attr, + char *buf) +{ + int ret; + struct stts751_priv *priv = dev_get_drvdata(dev); + + mutex_lock(&priv->access_lock); + ret = stts751_update(priv); + if (!ret) + priv->notify_min = true; + mutex_unlock(&priv->access_lock); + if (ret < 0) + return ret; + + return snprintf(buf, PAGE_SIZE - 1, "%d\n", priv->min_alert); +} + +static ssize_t show_input(struct device *dev, struct device_attribute *attr, + char *buf) +{ + int ret; + struct stts751_priv *priv = dev_get_drvdata(dev); + + mutex_lock(&priv->access_lock); + ret = stts751_update(priv); + mutex_unlock(&priv->access_lock); + if (ret < 0) + return ret; + + return snprintf(buf, PAGE_SIZE - 1, "%d\n", priv->temp); +} + +static ssize_t show_therm(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct stts751_priv *priv = dev_get_drvdata(dev); + + return snprintf(buf, PAGE_SIZE - 1, "%d\n", priv->therm); +} + +static ssize_t set_therm(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + int ret; + long temp; + struct stts751_priv *priv = dev_get_drvdata(dev); + + if (kstrtol(buf, 10, &temp) < 0) + return -EINVAL; + + /* HW works in range -64C to +127.937C */ + temp = clamp_val(temp, -64000, 127937); + mutex_lock(&priv->access_lock); + ret = stts751_set_temp_reg8(priv, temp, STTS751_REG_TLIM); + if (ret) + goto exit; + + dev_dbg(&priv->client->dev, "setting therm %ld", temp); + + /* + * hysteresis reg is relative to therm, so the HW does not need to be + * adjusted, we need to update our local copy only. + */ + priv->hyst = temp - (priv->therm - priv->hyst); + priv->therm = temp; + +exit: + mutex_unlock(&priv->access_lock); + if (ret) + return ret; + + return count; +} + +static ssize_t show_hyst(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct stts751_priv *priv = dev_get_drvdata(dev); + + return snprintf(buf, PAGE_SIZE - 1, "%d\n", priv->hyst); +} + +static ssize_t set_hyst(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + int ret; + long temp; + + struct stts751_priv *priv = dev_get_drvdata(dev); + + if (kstrtol(buf, 10, &temp) < 0) + return -EINVAL; + + mutex_lock(&priv->access_lock); + /* HW works in range -64C to +127.937C */ + temp = clamp_val(temp, -64000, priv->therm); + priv->hyst = temp; + dev_dbg(&priv->client->dev, "setting hyst %ld", temp); + temp = priv->therm - temp; + ret = stts751_set_temp_reg8(priv, temp, STTS751_REG_HYST); + mutex_unlock(&priv->access_lock); + if (ret) + return ret; + + return count; +} + +static ssize_t show_therm_trip(struct device *dev, + struct device_attribute *attr, char *buf) +{ + int ret; + struct stts751_priv *priv = dev_get_drvdata(dev); + + mutex_lock(&priv->access_lock); + ret = stts751_update(priv); + mutex_unlock(&priv->access_lock); + if (ret < 0) + return ret; + + return snprintf(buf, PAGE_SIZE - 1, "%d\n", priv->therm_trip); +} + +static ssize_t show_max(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct stts751_priv *priv = dev_get_drvdata(dev); + + return snprintf(buf, PAGE_SIZE - 1, "%d\n", priv->event_max); +} + +static ssize_t set_max(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + int ret; + long temp; + struct stts751_priv *priv = dev_get_drvdata(dev); + + if (kstrtol(buf, 10, &temp) < 0) + return -EINVAL; + + mutex_lock(&priv->access_lock); + /* HW works in range -64C to +127.937C */ + temp = clamp_val(temp, priv->event_min, 127937); + ret = stts751_set_temp_reg16(priv, temp, + STTS751_REG_HLIM_H, STTS751_REG_HLIM_L); + if (ret) + goto exit; + + dev_dbg(&priv->client->dev, "setting event max %ld", temp); + priv->event_max = temp; + ret = count; +exit: + mutex_unlock(&priv->access_lock); + return ret; +} + +static ssize_t show_min(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct stts751_priv *priv = dev_get_drvdata(dev); + + return snprintf(buf, PAGE_SIZE - 1, "%d\n", priv->event_min); +} + +static ssize_t set_min(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + int ret; + long temp; + struct stts751_priv *priv = dev_get_drvdata(dev); + + if (kstrtol(buf, 10, &temp) < 0) + return -EINVAL; + + mutex_lock(&priv->access_lock); + /* HW works in range -64C to +127.937C */ + temp = clamp_val(temp, -64000, priv->event_max); + ret = stts751_set_temp_reg16(priv, temp, + STTS751_REG_LLIM_H, STTS751_REG_LLIM_L); + if (ret) + goto exit; + + dev_dbg(&priv->client->dev, "setting event min %ld", temp); + priv->event_min = temp; + ret = count; +exit: + mutex_unlock(&priv->access_lock); + return ret; +} + +static ssize_t show_interval(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct stts751_priv *priv = dev_get_drvdata(dev); + + return snprintf(buf, PAGE_SIZE - 1, "%d\n", + stts751_intervals[priv->interval]); +} + +static ssize_t set_interval(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + unsigned long val; + int idx; + int ret = count; + struct stts751_priv *priv = dev_get_drvdata(dev); + + if (kstrtoul(buf, 10, &val) < 0) + return -EINVAL; + + idx = find_closest_descending(val, stts751_intervals, + ARRAY_SIZE(stts751_intervals)); + + dev_dbg(&priv->client->dev, "setting interval. req:%lu, idx: %d, val: %d", + val, idx, stts751_intervals[idx]); + + mutex_lock(&priv->access_lock); + if (priv->interval == idx) + goto exit; + + /* + * In early development stages I've become suspicious about the chip + * starting to misbehave if I ever set, even briefly, an invalid + * configuration. While I'm not sure this is really needed, be + * conservative and set rate/resolution in such an order that avoids + * passing through an invalid configuration. + */ + + /* speed up: lower the resolution, then modify convrate */ + if (priv->interval < idx) { + dev_dbg(&priv->client->dev, "lower resolution, then modify convrate"); + priv->interval = idx; + ret = stts751_adjust_resolution(priv); + if (ret) + goto exit; + } + + ret = i2c_smbus_write_byte_data(priv->client, STTS751_REG_RATE, idx); + if (ret) + goto exit; + /* slow down: modify convrate, then raise resolution */ + if (priv->interval != idx) { + dev_dbg(&priv->client->dev, "modify convrate, then raise resolution"); + priv->interval = idx; + ret = stts751_adjust_resolution(priv); + if (ret) + goto exit; + } + ret = count; +exit: + mutex_unlock(&priv->access_lock); + + return ret; +} + +static int stts751_detect(struct i2c_client *new_client, + struct i2c_board_info *info) +{ + struct i2c_adapter *adapter = new_client->adapter; + const char *name; + int tmp; + + if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) + return -ENODEV; + + tmp = i2c_smbus_read_byte_data(new_client, STTS751_REG_MAN_ID); + if (tmp != ST_MAN_ID) + return -ENODEV; + + /* lower temperaure registers always have bits 0-3 set to zero */ + tmp = i2c_smbus_read_byte_data(new_client, STTS751_REG_TEMP_L); + if (tmp & 0xf) + return -ENODEV; + + tmp = i2c_smbus_read_byte_data(new_client, STTS751_REG_HLIM_L); + if (tmp & 0xf) + return -ENODEV; + + tmp = i2c_smbus_read_byte_data(new_client, STTS751_REG_LLIM_L); + if (tmp & 0xf) + return -ENODEV; + + /* smbus timeout register always have bits 0-7 set to zero */ + tmp = i2c_smbus_read_byte_data(new_client, STTS751_REG_SMBUS_TO); + if (tmp & 0x7f) + return -ENODEV; + + tmp = i2c_smbus_read_byte_data(new_client, STTS751_REG_PROD_ID); + + switch (tmp) { + case STTS751_0_PROD_ID: + name = "STTS751-0"; + break; + case STTS751_1_PROD_ID: + name = "STTS751-1"; + break; + default: + return -ENODEV; + } + dev_dbg(&new_client->dev, "Chip %s detected", name); + + strlcpy(info->type, stts751_id[0].name, I2C_NAME_SIZE); + return 0; +} + +static int stts751_read_chip_config(struct stts751_priv *priv) +{ + int ret; + int tmp; + + ret = i2c_smbus_read_byte_data(priv->client, STTS751_REG_CONF); + if (ret < 0) + return ret; + priv->config = ret; + priv->res = (ret & STTS751_CONF_RES_MASK) >> STTS751_CONF_RES_SHIFT; + + ret = i2c_smbus_read_byte_data(priv->client, STTS751_REG_RATE); + if (ret < 0) + return ret; + priv->interval = ret; + + ret = stts751_read_reg16(priv, &priv->event_max, + STTS751_REG_HLIM_H, STTS751_REG_HLIM_L); + if (ret) + return ret; + + ret = stts751_read_reg16(priv, &priv->event_min, + STTS751_REG_LLIM_H, STTS751_REG_LLIM_L); + if (ret) + return ret; + + ret = stts751_read_reg8(priv, &priv->therm, STTS751_REG_TLIM); + if (ret) + return ret; + + ret = stts751_read_reg8(priv, &tmp, STTS751_REG_HYST); + if (ret) + return ret; + priv->hyst = priv->therm - tmp; + + return 0; +} + +static SENSOR_DEVICE_ATTR(temp1_input, 0444, show_input, NULL, 0); +static SENSOR_DEVICE_ATTR(temp1_min, 0644, show_min, set_min, 0); +static SENSOR_DEVICE_ATTR(temp1_max, 0644, show_max, set_max, 0); +static SENSOR_DEVICE_ATTR(temp1_min_alarm, 0444, show_min_alarm, NULL, 0); +static SENSOR_DEVICE_ATTR(temp1_max_alarm, 0444, show_max_alarm, NULL, 0); +static SENSOR_DEVICE_ATTR(temp1_crit, 0644, show_therm, set_therm, 0); +static SENSOR_DEVICE_ATTR(temp1_crit_hyst, 0644, show_hyst, set_hyst, 0); +static SENSOR_DEVICE_ATTR(temp1_crit_alarm, 0444, show_therm_trip, NULL, 0); +static SENSOR_DEVICE_ATTR(update_interval, 0644, + show_interval, set_interval, 0); + +static struct attribute *stts751_attrs[] = { + &sensor_dev_attr_temp1_input.dev_attr.attr, + &sensor_dev_attr_temp1_min.dev_attr.attr, + &sensor_dev_attr_temp1_max.dev_attr.attr, + &sensor_dev_attr_temp1_min_alarm.dev_attr.attr, + &sensor_dev_attr_temp1_max_alarm.dev_attr.attr, + &sensor_dev_attr_temp1_crit.dev_attr.attr, + &sensor_dev_attr_temp1_crit_hyst.dev_attr.attr, + &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr, + &sensor_dev_attr_update_interval.dev_attr.attr, + NULL +}; +ATTRIBUTE_GROUPS(stts751); + +static int stts751_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct stts751_priv *priv; + int ret; + bool smbus_nto; + int rev_id; + + priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + priv->client = client; + priv->notify_max = true; + priv->notify_min = true; + i2c_set_clientdata(client, priv); + mutex_init(&priv->access_lock); + + if (device_property_present(&client->dev, + "smbus-timeout-disable")) { + smbus_nto = device_property_read_bool(&client->dev, + "smbus-timeout-disable"); + + ret = i2c_smbus_write_byte_data(client, STTS751_REG_SMBUS_TO, + smbus_nto ? 0 : 0x80); + if (ret) + return ret; + } + + rev_id = i2c_smbus_read_byte_data(client, STTS751_REG_REV_ID); + if (rev_id < 0) + return -ENODEV; + if (rev_id != 0x1) { + dev_dbg(&client->dev, "Chip revision 0x%x is untested\n", + rev_id); + } + + ret = stts751_read_chip_config(priv); + if (ret) + return ret; + + priv->config &= ~(STTS751_CONF_STOP | STTS751_CONF_EVENT_DIS); + ret = i2c_smbus_write_byte_data(client, STTS751_REG_CONF, priv->config); + if (ret) + return ret; + + priv->dev = devm_hwmon_device_register_with_groups(&client->dev, + client->name, priv, + stts751_groups); + return PTR_ERR_OR_ZERO(priv->dev); +} + +MODULE_DEVICE_TABLE(i2c, stts751_id); + +static struct i2c_driver stts751_driver = { + .class = I2C_CLASS_HWMON, + .driver = { + .name = DEVNAME, + }, + .probe = stts751_probe, + .id_table = stts751_id, + .detect = stts751_detect, + .alert = stts751_alert, + .address_list = normal_i2c, +}; + +module_i2c_driver(stts751_driver); + +MODULE_AUTHOR("Andrea Merello <andrea.merello@gmail.com>"); +MODULE_DESCRIPTION("STTS751 sensor driver"); +MODULE_LICENSE("GPL"); |