* [PATCH v4 1/2] hwmon: new driver for ST stts751 thermal sensor
@ 2017-01-26 14:17 Andrea Merello
2017-01-26 14:17 ` [PATCH v4 2/2] DT: add binding documentation for STTS751 Andrea Merello
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: Andrea Merello @ 2017-01-26 14:17 UTC (permalink / raw)
To: linux-hwmon; +Cc: Andrea Merello, LABBE Corentin, Guenter Roeck, Jean Delvare
This patch adds a HWMON driver for ST Microelectronics STTS751
temperature sensors.
Changes since V3:
- fix sysfs_notify() filename
- simplify error exit path in stts751_update_temp(): kill useless goto
- fix set function were racy due to lock incorrectly placed
- use msecs_to_jiffies instead of manual calculation
- fix jiffies and msecs were mixed up
- don't mark cache as good unless reads really succeded to fill up it
- when updating therm, hyst keeps relative value rather than abs value
- don't should in dev_dbg when chip is detected
- don't ever generate two uevents
- clarify clear-on-read behaviour of status reg alarm flags
- simplify mDEG to HW conversion function
- fix chip stops due to incorrect resolution configuration
- fix incorrectly reading negative numbers from HW
Thanks-to: LABBE Corentin [for suggestions]
Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Cc: LABBE Corentin <clabbe.montjoie@gmail.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Jean Delvare <jdelvare@suse.com>
---
drivers/hwmon/Kconfig | 10 +
drivers/hwmon/Makefile | 1 +
drivers/hwmon/stts751.c | 803 ++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 814 insertions(+)
create mode 100644 drivers/hwmon/stts751.c
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index d1f82f2..8fdd241 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -1448,6 +1448,16 @@ config SENSORS_SCH5636
This driver can also be built as a module. If so, the module
will be called sch5636.
+config SENSORS_STTS751
+ tristate "ST Microelectronics STTS751"
+ depends on I2C
+ help
+ If you say yes here you get support for STTS751
+ temperature sensor chips.
+
+ This driver can also be built as a module. If so, the module
+ will be called stts751.
+
config SENSORS_SMM665
tristate "Summit Microelectronics SMM665"
depends on I2C
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 7476b22..1114130 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -147,6 +147,7 @@ obj-$(CONFIG_SENSORS_SMM665) += smm665.o
obj-$(CONFIG_SENSORS_SMSC47B397)+= smsc47b397.o
obj-$(CONFIG_SENSORS_SMSC47M1) += smsc47m1.o
obj-$(CONFIG_SENSORS_SMSC47M192)+= smsc47m192.o
+obj-$(CONFIG_SENSORS_STTS751) += stts751.o
obj-$(CONFIG_SENSORS_AMC6821) += amc6821.o
obj-$(CONFIG_SENSORS_TC74) += tc74.o
obj-$(CONFIG_SENSORS_THMC50) += thmc50.o
diff --git a/drivers/hwmon/stts751.c b/drivers/hwmon/stts751.c
new file mode 100644
index 0000000..de7298f
--- /dev/null
+++ b/drivers/hwmon/stts751.c
@@ -0,0 +1,803 @@
+/*
+ * 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;
+};
+
+/*
+ * 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->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->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->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->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->client->dev,
+ "Alert received, but can't communicate to the device. Something bad happening? Triggering all alarms!");
+ }
+
+ if (priv->max_alert) {
+ dev_notice(&client->dev, "got alert for HIGH temperature");
+
+ /* unblock alert poll */
+ sysfs_notify(&priv->dev->kobj, NULL, "temp1_max_alarm");
+ }
+
+ if (priv->min_alert) {
+ dev_notice(&client->dev, "got alert for LOW temperature");
+
+ /* 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 = 0;
+ int cache_time = msecs_to_jiffies(stts751_intervals[priv->interval]);
+
+ mutex_lock(&priv->access_lock);
+ if (time_after(jiffies, priv->last_update + cache_time) ||
+ !priv->data_valid) {
+ ret = stts751_update_temp(priv);
+ if (ret)
+ goto exit;
+
+ ret = stts751_update_alert(priv);
+ if (ret)
+ goto exit;
+ priv->data_valid = true;
+ priv->last_update = jiffies;
+ }
+exit:
+ mutex_unlock(&priv->access_lock);
+
+ return ret;
+}
+
+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);
+
+ ret = stts751_update(priv);
+ 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);
+
+ ret = stts751_update(priv);
+ 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);
+
+ ret = stts751_update(priv);
+ 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(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->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);
+
+ ret = stts751_update(priv);
+ 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(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(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 = 0;
+ 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(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->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->dev, "modify convrate, then raise resolution");
+ priv->interval = idx;
+ ret = stts751_adjust_resolution(priv);
+ if (ret)
+ goto exit;
+ }
+exit:
+ mutex_unlock(&priv->access_lock);
+
+ return count;
+}
+
+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 mfg_id, prod_id, rev_id;
+
+ if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
+ return -ENODEV;
+
+ mfg_id = i2c_smbus_read_byte_data(new_client, ST_MAN_ID);
+ if (mfg_id != ST_MAN_ID)
+ return -ENODEV;
+
+ prod_id = i2c_smbus_read_byte_data(new_client, STTS751_REG_PROD_ID);
+
+ switch (prod_id) {
+ 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);
+
+ rev_id = i2c_smbus_read_byte_data(new_client, STTS751_REG_REV_ID);
+ if (rev_id < 0)
+ return -ENODEV;
+ if (rev_id != 0x1) {
+ dev_notice(&new_client->dev,
+ "Chip revision 0x%x is untested\nPlease report whether it works to andrea.merello@gmail.com",
+ rev_id);
+ }
+
+ 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 ret;
+}
+
+static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_input, NULL, 0);
+static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_min, set_min, 0);
+static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_max, set_max, 0);
+static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_min_alarm, NULL, 0);
+static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_max_alarm, NULL, 0);
+static SENSOR_DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_therm,
+ set_therm, 0);
+static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_hyst,
+ set_hyst, 0);
+static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_therm_trip, NULL, 0);
+static SENSOR_DEVICE_ATTR(update_interval, S_IWUSR | S_IRUGO,
+ 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_to;
+
+ priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->client = client;
+ i2c_set_clientdata(client, priv);
+ mutex_init(&priv->access_lock);
+
+ if (device_property_present(&client->dev,
+ "smbus-timeout-disable")) {
+ smbus_to = !device_property_read_bool(&client->dev,
+ "smbus-timeout-disable");
+
+ ret = i2c_smbus_write_byte_data(priv->client,
+ STTS751_REG_SMBUS_TO,
+ smbus_to ? 0x80 : 0);
+ if (ret)
+ return ret;
+ }
+
+ 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(priv->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");
--
2.7.4
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH v4 2/2] DT: add binding documentation for STTS751
2017-01-26 14:17 [PATCH v4 1/2] hwmon: new driver for ST stts751 thermal sensor Andrea Merello
@ 2017-01-26 14:17 ` Andrea Merello
2017-01-29 18:13 ` [PATCH v4 1/2] hwmon: new driver for ST stts751 thermal sensor Guenter Roeck
2017-01-29 18:18 ` Guenter Roeck
2 siblings, 0 replies; 6+ messages in thread
From: Andrea Merello @ 2017-01-26 14:17 UTC (permalink / raw)
To: linux-hwmon; +Cc: Andrea Merello, Rob Herring, Mark Rutland
Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
---
Documentation/devicetree/bindings/hwmon/stts751.txt | 15 +++++++++++++++
1 file changed, 15 insertions(+)
create mode 100644 Documentation/devicetree/bindings/hwmon/stts751.txt
diff --git a/Documentation/devicetree/bindings/hwmon/stts751.txt b/Documentation/devicetree/bindings/hwmon/stts751.txt
new file mode 100644
index 0000000..3ee1dc3
--- /dev/null
+++ b/Documentation/devicetree/bindings/hwmon/stts751.txt
@@ -0,0 +1,15 @@
+* STTS751 thermometer.
+
+Required node properties:
+- compatible: "stts751"
+- reg: I2C bus address of the device
+
+Optional properties:
+- smbus-timeout-disable: when set, the smbus timeout function will be disabled
+
+Example stts751 node:
+
+temp-sensor {
+ compatible = "stts751";
+ reg = <0x48>;
+}
--
2.7.4
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH v4 1/2] hwmon: new driver for ST stts751 thermal sensor
2017-01-26 14:17 [PATCH v4 1/2] hwmon: new driver for ST stts751 thermal sensor Andrea Merello
2017-01-26 14:17 ` [PATCH v4 2/2] DT: add binding documentation for STTS751 Andrea Merello
@ 2017-01-29 18:13 ` Guenter Roeck
2017-01-30 7:36 ` Andrea Merello
2017-01-29 18:18 ` Guenter Roeck
2 siblings, 1 reply; 6+ messages in thread
From: Guenter Roeck @ 2017-01-29 18:13 UTC (permalink / raw)
To: Andrea Merello, linux-hwmon; +Cc: LABBE Corentin, Jean Delvare
On 01/26/2017 06:17 AM, Andrea Merello wrote:
> This patch adds a HWMON driver for ST Microelectronics STTS751
> temperature sensors.
>
> Changes since V3:
> - fix sysfs_notify() filename
> - simplify error exit path in stts751_update_temp(): kill useless goto
> - fix set function were racy due to lock incorrectly placed
> - use msecs_to_jiffies instead of manual calculation
> - fix jiffies and msecs were mixed up
> - don't mark cache as good unless reads really succeded to fill up it
> - when updating therm, hyst keeps relative value rather than abs value
> - don't should in dev_dbg when chip is detected
> - don't ever generate two uevents
> - clarify clear-on-read behaviour of status reg alarm flags
> - simplify mDEG to HW conversion function
> - fix chip stops due to incorrect resolution configuration
> - fix incorrectly reading negative numbers from HW
>
> Thanks-to: LABBE Corentin [for suggestions]
> Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
> Cc: LABBE Corentin <clabbe.montjoie@gmail.com>
> Cc: Guenter Roeck <linux@roeck-us.net>
> Cc: Jean Delvare <jdelvare@suse.com>
> ---
> drivers/hwmon/Kconfig | 10 +
> drivers/hwmon/Makefile | 1 +
> drivers/hwmon/stts751.c | 803 ++++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 814 insertions(+)
> create mode 100644 drivers/hwmon/stts751.c
>
> diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
> index d1f82f2..8fdd241 100644
> --- a/drivers/hwmon/Kconfig
> +++ b/drivers/hwmon/Kconfig
> @@ -1448,6 +1448,16 @@ config SENSORS_SCH5636
> This driver can also be built as a module. If so, the module
> will be called sch5636.
>
> +config SENSORS_STTS751
> + tristate "ST Microelectronics STTS751"
> + depends on I2C
> + help
> + If you say yes here you get support for STTS751
> + temperature sensor chips.
> +
> + This driver can also be built as a module. If so, the module
> + will be called stts751.
> +
> config SENSORS_SMM665
> tristate "Summit Microelectronics SMM665"
> depends on I2C
> diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
> index 7476b22..1114130 100644
> --- a/drivers/hwmon/Makefile
> +++ b/drivers/hwmon/Makefile
> @@ -147,6 +147,7 @@ obj-$(CONFIG_SENSORS_SMM665) += smm665.o
> obj-$(CONFIG_SENSORS_SMSC47B397)+= smsc47b397.o
> obj-$(CONFIG_SENSORS_SMSC47M1) += smsc47m1.o
> obj-$(CONFIG_SENSORS_SMSC47M192)+= smsc47m192.o
> +obj-$(CONFIG_SENSORS_STTS751) += stts751.o
> obj-$(CONFIG_SENSORS_AMC6821) += amc6821.o
> obj-$(CONFIG_SENSORS_TC74) += tc74.o
> obj-$(CONFIG_SENSORS_THMC50) += thmc50.o
> diff --git a/drivers/hwmon/stts751.c b/drivers/hwmon/stts751.c
> new file mode 100644
> index 0000000..de7298f
> --- /dev/null
> +++ b/drivers/hwmon/stts751.c
> @@ -0,0 +1,803 @@
> +/*
> + * 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;
> +};
> +
> +/*
> + * 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->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);
Please align continuation lines with '('.
> +}
> +
> +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);
This continuation line is unnecessary (there may be others, but I did not check).
> +}
> +
> +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->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->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->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->client->dev,
> + "Alert received, but can't communicate to the device. Something bad happening? Triggering all alarms!");
I would suggest to drop the "Something bad happening?". That should be obvious
from the message.
> + }
> +
> + if (priv->max_alert) {
> + dev_notice(&client->dev, "got alert for HIGH temperature");
> +
> + /* unblock alert poll */
> + sysfs_notify(&priv->dev->kobj, NULL, "temp1_max_alarm");
> + }
> +
> + if (priv->min_alert) {
> + dev_notice(&client->dev, "got alert for LOW temperature");
> +
> + /* 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 = 0;
> + int cache_time = msecs_to_jiffies(stts751_intervals[priv->interval]);
> +
> + mutex_lock(&priv->access_lock);
> + if (time_after(jiffies, priv->last_update + cache_time) ||
> + !priv->data_valid) {
> + ret = stts751_update_temp(priv);
> + if (ret)
> + goto exit;
> +
> + ret = stts751_update_alert(priv);
> + if (ret)
> + goto exit;
> + priv->data_valid = true;
> + priv->last_update = jiffies;
> + }
> +exit:
> + mutex_unlock(&priv->access_lock);
> +
> + return ret;
> +}
> +
> +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);
> +
> + ret = stts751_update(priv);
> + 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);
> +
> + ret = stts751_update(priv);
> + 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);
> +
> + ret = stts751_update(priv);
> + 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(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->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);
> +
> + ret = stts751_update(priv);
> + 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(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(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 = 0;
> + 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(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->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->dev, "modify convrate, then raise resolution");
> + priv->interval = idx;
> + ret = stts751_adjust_resolution(priv);
> + if (ret)
> + goto exit;
All those gotos ignore the error. Is this really what you want ?
> + }
> +exit:
> + mutex_unlock(&priv->access_lock);
> +
> + return count;
Should this be
return ret ? ret : count;
instead ? Or maybe
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 mfg_id, prod_id, rev_id;
> +
> + if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
> + return -ENODEV;
> +
> + mfg_id = i2c_smbus_read_byte_data(new_client, ST_MAN_ID);
> + if (mfg_id != ST_MAN_ID)
> + return -ENODEV;
> +
> + prod_id = i2c_smbus_read_byte_data(new_client, STTS751_REG_PROD_ID);
> +
> + switch (prod_id) {
> + 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);
> +
> + rev_id = i2c_smbus_read_byte_data(new_client, STTS751_REG_REV_ID);
> + if (rev_id < 0)
> + return -ENODEV;
> + if (rev_id != 0x1) {
> + dev_notice(&new_client->dev,
> + "Chip revision 0x%x is untested\nPlease report whether it works to andrea.merello@gmail.com",
> + rev_id);
> + }
You might consider moving the rev_id warning to the probe function.
In many if not most cases, the detect function won't run at all
(since the chip will be instantiated explicitly), and you won't get
the warning.
On the other side, do you really think the warning adds any real value ?
I am a bit concerned that it will just create noise a few years down the road.
On the other side, it might be useful to add a couple of additional registers
to the check to improve its reliability and reduce possible false positives.
The temperature low bytes (registers 0x02, 0x06, 0x08) would be good targets
with the lower 4 bits being 0. An excellent target would be the SMBus timeout
register, which has 7 bits known to be 0.
> +
> + 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 ret;
return 0;
> +}
> +
> +static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_input, NULL, 0);
> +static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_min, set_min, 0);
> +static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_max, set_max, 0);
> +static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_min_alarm, NULL, 0);
> +static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_max_alarm, NULL, 0);
> +static SENSOR_DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_therm,
> + set_therm, 0);
> +static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_hyst,
> + set_hyst, 0);
> +static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_therm_trip, NULL, 0);
> +static SENSOR_DEVICE_ATTR(update_interval, S_IWUSR | S_IRUGO,
> + 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_to;
> +
> + priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL);
> + if (!priv)
> + return -ENOMEM;
> +
> + priv->client = client;
> + i2c_set_clientdata(client, priv);
> + mutex_init(&priv->access_lock);
> +
> + if (device_property_present(&client->dev,
> + "smbus-timeout-disable")) {
> + smbus_to = !device_property_read_bool(&client->dev,
> + "smbus-timeout-disable");
> +
This "!" is really unnecessary. Just name the variable differently,
> + ret = i2c_smbus_write_byte_data(priv->client,
> + STTS751_REG_SMBUS_TO,
> + smbus_to ? 0x80 : 0);
and reverse the logic here.
> + if (ret)
> + return ret;
> + }
> +
> + 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(priv->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");
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v4 1/2] hwmon: new driver for ST stts751 thermal sensor
2017-01-26 14:17 [PATCH v4 1/2] hwmon: new driver for ST stts751 thermal sensor Andrea Merello
2017-01-26 14:17 ` [PATCH v4 2/2] DT: add binding documentation for STTS751 Andrea Merello
2017-01-29 18:13 ` [PATCH v4 1/2] hwmon: new driver for ST stts751 thermal sensor Guenter Roeck
@ 2017-01-29 18:18 ` Guenter Roeck
2017-01-30 7:36 ` Andrea Merello
2 siblings, 1 reply; 6+ messages in thread
From: Guenter Roeck @ 2017-01-29 18:18 UTC (permalink / raw)
To: Andrea Merello, linux-hwmon; +Cc: LABBE Corentin, Jean Delvare
On 01/26/2017 06:17 AM, Andrea Merello wrote:
> This patch adds a HWMON driver for ST Microelectronics STTS751
> temperature sensors.
>
> Changes since V3:
> - fix sysfs_notify() filename
> - simplify error exit path in stts751_update_temp(): kill useless goto
> - fix set function were racy due to lock incorrectly placed
> - use msecs_to_jiffies instead of manual calculation
> - fix jiffies and msecs were mixed up
> - don't mark cache as good unless reads really succeded to fill up it
> - when updating therm, hyst keeps relative value rather than abs value
> - don't should in dev_dbg when chip is detected
> - don't ever generate two uevents
> - clarify clear-on-read behaviour of status reg alarm flags
> - simplify mDEG to HW conversion function
> - fix chip stops due to incorrect resolution configuration
> - fix incorrectly reading negative numbers from HW
>
> Thanks-to: LABBE Corentin [for suggestions]
> Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
> Cc: LABBE Corentin <clabbe.montjoie@gmail.com>
> Cc: Guenter Roeck <linux@roeck-us.net>
> Cc: Jean Delvare <jdelvare@suse.com>
[ ... ]
> +
> +static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_input, NULL, 0);
> +static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_min, set_min, 0);
> +static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_max, set_max, 0);
> +static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_min_alarm, NULL, 0);
> +static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_max_alarm, NULL, 0);
> +static SENSOR_DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_therm,
> + set_therm, 0);
> +static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_hyst,
> + set_hyst, 0);
> +static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_therm_trip, NULL, 0);
> +static SENSOR_DEVICE_ATTR(update_interval, S_IWUSR | S_IRUGO,
> + show_interval, set_interval, 0);
I forgot to mention: Symbolic permissions ran out of favor upstream.
Please use octals above to make the annoying checkpatch warnings go away.
Thanks,
Guenter
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v4 1/2] hwmon: new driver for ST stts751 thermal sensor
2017-01-29 18:13 ` [PATCH v4 1/2] hwmon: new driver for ST stts751 thermal sensor Guenter Roeck
@ 2017-01-30 7:36 ` Andrea Merello
0 siblings, 0 replies; 6+ messages in thread
From: Andrea Merello @ 2017-01-30 7:36 UTC (permalink / raw)
To: Guenter Roeck; +Cc: linux-hwmon, LABBE Corentin, Jean Delvare
On Sun, Jan 29, 2017 at 7:13 PM, Guenter Roeck <linux@roeck-us.net> wrote:
> On 01/26/2017 06:17 AM, Andrea Merello wrote:
>>
>> This patch adds a HWMON driver for ST Microelectronics STTS751
>> temperature sensors.
>>
>> Changes since V3:
>> - fix sysfs_notify() filename
>> - simplify error exit path in stts751_update_temp(): kill useless goto
>> - fix set function were racy due to lock incorrectly placed
>> - use msecs_to_jiffies instead of manual calculation
>> - fix jiffies and msecs were mixed up
>> - don't mark cache as good unless reads really succeded to fill up it
>> - when updating therm, hyst keeps relative value rather than abs value
>> - don't should in dev_dbg when chip is detected
>> - don't ever generate two uevents
>> - clarify clear-on-read behaviour of status reg alarm flags
>> - simplify mDEG to HW conversion function
>> - fix chip stops due to incorrect resolution configuration
>> - fix incorrectly reading negative numbers from HW
>>
>> Thanks-to: LABBE Corentin [for suggestions]
>> Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
>> Cc: LABBE Corentin <clabbe.montjoie@gmail.com>
>> Cc: Guenter Roeck <linux@roeck-us.net>
>> Cc: Jean Delvare <jdelvare@suse.com>
>> ---
>> drivers/hwmon/Kconfig | 10 +
>> drivers/hwmon/Makefile | 1 +
>> drivers/hwmon/stts751.c | 803
>> ++++++++++++++++++++++++++++++++++++++++++++++++
>> 3 files changed, 814 insertions(+)
>> create mode 100644 drivers/hwmon/stts751.c
>>
>> diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
>> index d1f82f2..8fdd241 100644
>> --- a/drivers/hwmon/Kconfig
>> +++ b/drivers/hwmon/Kconfig
>> @@ -1448,6 +1448,16 @@ config SENSORS_SCH5636
>> This driver can also be built as a module. If so, the module
>> will be called sch5636.
>>
>> +config SENSORS_STTS751
>> + tristate "ST Microelectronics STTS751"
>> + depends on I2C
>> + help
>> + If you say yes here you get support for STTS751
>> + temperature sensor chips.
>> +
>> + This driver can also be built as a module. If so, the module
>> + will be called stts751.
>> +
>> config SENSORS_SMM665
>> tristate "Summit Microelectronics SMM665"
>> depends on I2C
>> diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
>> index 7476b22..1114130 100644
>> --- a/drivers/hwmon/Makefile
>> +++ b/drivers/hwmon/Makefile
>> @@ -147,6 +147,7 @@ obj-$(CONFIG_SENSORS_SMM665) += smm665.o
>> obj-$(CONFIG_SENSORS_SMSC47B397)+= smsc47b397.o
>> obj-$(CONFIG_SENSORS_SMSC47M1) += smsc47m1.o
>> obj-$(CONFIG_SENSORS_SMSC47M192)+= smsc47m192.o
>> +obj-$(CONFIG_SENSORS_STTS751) += stts751.o
>> obj-$(CONFIG_SENSORS_AMC6821) += amc6821.o
>> obj-$(CONFIG_SENSORS_TC74) += tc74.o
>> obj-$(CONFIG_SENSORS_THMC50) += thmc50.o
>> diff --git a/drivers/hwmon/stts751.c b/drivers/hwmon/stts751.c
>> new file mode 100644
>> index 0000000..de7298f
>> --- /dev/null
>> +++ b/drivers/hwmon/stts751.c
>> @@ -0,0 +1,803 @@
>> +/*
>> + * 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;
>> +};
>> +
>> +/*
>> + * 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->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);
>
>
> Please align continuation lines with '('.
OK
>
>> +}
>> +
>> +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);
>
>
> This continuation line is unnecessary (there may be others, but I did not
> check).
OK
>
>> +}
>> +
>> +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->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->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->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->client->dev,
>> + "Alert received, but can't communicate to the
>> device. Something bad happening? Triggering all alarms!");
>
>
> I would suggest to drop the "Something bad happening?". That should be
> obvious
> from the message.
OK
>
>> + }
>> +
>> + if (priv->max_alert) {
>> + dev_notice(&client->dev, "got alert for HIGH
>> temperature");
>> +
>> + /* unblock alert poll */
>> + sysfs_notify(&priv->dev->kobj, NULL, "temp1_max_alarm");
>> + }
>> +
>> + if (priv->min_alert) {
>> + dev_notice(&client->dev, "got alert for LOW temperature");
>> +
>> + /* 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 = 0;
>> + int cache_time =
>> msecs_to_jiffies(stts751_intervals[priv->interval]);
>> +
>> + mutex_lock(&priv->access_lock);
>> + if (time_after(jiffies, priv->last_update + cache_time) ||
>> + !priv->data_valid) {
>> + ret = stts751_update_temp(priv);
>> + if (ret)
>> + goto exit;
>> +
>> + ret = stts751_update_alert(priv);
>> + if (ret)
>> + goto exit;
>> + priv->data_valid = true;
>> + priv->last_update = jiffies;
>> + }
>> +exit:
>> + mutex_unlock(&priv->access_lock);
>> +
>> + return ret;
>> +}
>> +
>> +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);
>> +
>> + ret = stts751_update(priv);
>> + 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);
>> +
>> + ret = stts751_update(priv);
>> + 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);
>> +
>> + ret = stts751_update(priv);
>> + 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(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->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);
>> +
>> + ret = stts751_update(priv);
>> + 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(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(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 = 0;
>> + 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(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->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->dev, "modify convrate, then raise
>> resolution");
>> + priv->interval = idx;
>> + ret = stts751_adjust_resolution(priv);
>> + if (ret)
>> + goto exit;
>
>
> All those gotos ignore the error. Is this really what you want ?
You are right.. It was unintentional..
>> + }
>> +exit:
>> + mutex_unlock(&priv->access_lock);
>> +
>> + return count;
>
>
> Should this be
>
> return ret ? ret : count;
>
> instead ? Or maybe
>
> ret = count;
> exit:
> mutex_unlock(&priv->access_lock);
> return ret;
going to use the latter one..
>> +}
>> +
>>
>> +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 mfg_id, prod_id, rev_id;
>> +
>> + if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
>> + return -ENODEV;
>> +
>> + mfg_id = i2c_smbus_read_byte_data(new_client, ST_MAN_ID);
>> + if (mfg_id != ST_MAN_ID)
>> + return -ENODEV;
>> +
>> + prod_id = i2c_smbus_read_byte_data(new_client,
>> STTS751_REG_PROD_ID);
>> +
>> + switch (prod_id) {
>> + 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);
>> +
>> + rev_id = i2c_smbus_read_byte_data(new_client, STTS751_REG_REV_ID);
>> + if (rev_id < 0)
>> + return -ENODEV;
>> + if (rev_id != 0x1) {
>> + dev_notice(&new_client->dev,
>> + "Chip revision 0x%x is untested\nPlease report
>> whether it works to andrea.merello@gmail.com",
>> + rev_id);
>> + }
>
>
> You might consider moving the rev_id warning to the probe function.
> In many if not most cases, the detect function won't run at all
> (since the chip will be instantiated explicitly), and you won't get
> the warning.
>
> On the other side, do you really think the warning adds any real value ?
> I am a bit concerned that it will just create noise a few years down the
> road.
OK. I've moved this check to the probe function, and I've changed the
dev_notice in dev_dbg: I would assume (hope) that different chip
revisions are still register-compatible and should work, however if it
happens that someone has trouble and he/she is debugging this driver,
IMHO it's worth to eventually tell him/her that he/she is using an
unknown chip revision. This way we will avoid noise during normal
usage.
> On the other side, it might be useful to add a couple of additional
> registers
> to the check to improve its reliability and reduce possible false positives.
> The temperature low bytes (registers 0x02, 0x06, 0x08) would be good targets
> with the lower 4 bits being 0. An excellent target would be the SMBus
> timeout
> register, which has 7 bits known to be 0.
OK, good idea :)
>
>> +
>> + 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 ret;
>
>
> return 0;
OK
>
>> +}
>> +
>>
>> +static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_input, NULL, 0);
>> +static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_min,
>> set_min, 0);
>> +static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_max,
>> set_max, 0);
>> +static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_min_alarm, NULL,
>> 0);
>> +static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_max_alarm, NULL,
>> 0);
>> +static SENSOR_DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_therm,
>> + set_therm, 0);
>> +static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_hyst,
>> + set_hyst, 0);
>> +static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_therm_trip,
>> NULL, 0);
>> +static SENSOR_DEVICE_ATTR(update_interval, S_IWUSR | S_IRUGO,
>> + 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_to;
>> +
>> + priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL);
>> + if (!priv)
>> + return -ENOMEM;
>> +
>> + priv->client = client;
>> + i2c_set_clientdata(client, priv);
>> + mutex_init(&priv->access_lock);
>> +
>> + if (device_property_present(&client->dev,
>> + "smbus-timeout-disable")) {
>> + smbus_to = !device_property_read_bool(&client->dev,
>> + "smbus-timeout-disable");
>> +
>
> This "!" is really unnecessary. Just name the variable differently,
>
>> + ret = i2c_smbus_write_byte_data(priv->client,
>> + STTS751_REG_SMBUS_TO,
>> + smbus_to ? 0x80 : 0);
>
>
> and reverse the logic here.
OK
>
>
>> + if (ret)
>> + return ret;
>> + }
>> +
>> + 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(priv->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");
>>
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v4 1/2] hwmon: new driver for ST stts751 thermal sensor
2017-01-29 18:18 ` Guenter Roeck
@ 2017-01-30 7:36 ` Andrea Merello
0 siblings, 0 replies; 6+ messages in thread
From: Andrea Merello @ 2017-01-30 7:36 UTC (permalink / raw)
To: Guenter Roeck; +Cc: linux-hwmon, LABBE Corentin, Jean Delvare
On Sun, Jan 29, 2017 at 7:18 PM, Guenter Roeck <linux@roeck-us.net> wrote:
> On 01/26/2017 06:17 AM, Andrea Merello wrote:
>>
>> This patch adds a HWMON driver for ST Microelectronics STTS751
>> temperature sensors.
>>
>> Changes since V3:
>> - fix sysfs_notify() filename
>> - simplify error exit path in stts751_update_temp(): kill useless goto
>> - fix set function were racy due to lock incorrectly placed
>> - use msecs_to_jiffies instead of manual calculation
>> - fix jiffies and msecs were mixed up
>> - don't mark cache as good unless reads really succeded to fill up it
>> - when updating therm, hyst keeps relative value rather than abs value
>> - don't should in dev_dbg when chip is detected
>> - don't ever generate two uevents
>> - clarify clear-on-read behaviour of status reg alarm flags
>> - simplify mDEG to HW conversion function
>> - fix chip stops due to incorrect resolution configuration
>> - fix incorrectly reading negative numbers from HW
>>
>> Thanks-to: LABBE Corentin [for suggestions]
>> Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
>> Cc: LABBE Corentin <clabbe.montjoie@gmail.com>
>> Cc: Guenter Roeck <linux@roeck-us.net>
>> Cc: Jean Delvare <jdelvare@suse.com>
>
>
> [ ... ]
>
>> +
>> +static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_input, NULL, 0);
>> +static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_min,
>> set_min, 0);
>> +static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_max,
>> set_max, 0);
>> +static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_min_alarm, NULL,
>> 0);
>> +static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_max_alarm, NULL,
>> 0);
>> +static SENSOR_DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_therm,
>> + set_therm, 0);
>> +static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_hyst,
>> + set_hyst, 0);
>> +static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_therm_trip,
>> NULL, 0);
>> +static SENSOR_DEVICE_ATTR(update_interval, S_IWUSR | S_IRUGO,
>> + show_interval, set_interval, 0);
>
>
> I forgot to mention: Symbolic permissions ran out of favor upstream.
> Please use octals above to make the annoying checkpatch warnings go away.
OK
> Thanks,
> Guenter
>
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2017-01-30 7:36 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-01-26 14:17 [PATCH v4 1/2] hwmon: new driver for ST stts751 thermal sensor Andrea Merello
2017-01-26 14:17 ` [PATCH v4 2/2] DT: add binding documentation for STTS751 Andrea Merello
2017-01-29 18:13 ` [PATCH v4 1/2] hwmon: new driver for ST stts751 thermal sensor Guenter Roeck
2017-01-30 7:36 ` Andrea Merello
2017-01-29 18:18 ` Guenter Roeck
2017-01-30 7:36 ` Andrea Merello
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