hwmon: (adt7410) Add support for the adt7310/adt7320

The adt7310/adt7320 is the SPI version of the adt7410/adt7420. The register map
layout is a bit different, i.e. the register addresses differ between the two
variants, but the bit layouts of the individual registers are identical. So both
chip variants can easily be supported by the same driver. The issue of non
matching register address layouts is solved by a simple look-up table which
translates the I2C addresses to the SPI addresses.

The patch moves the bulk of the adt7410 driver to a common module that will be
shared by the adt7410 and adt7310 drivers. This common module implements the
driver logic and uses a set of virtual functions to perform IO access. The
adt7410 and adt7310 driver modules provide proper implementations of these IO
accessor functions for I2C respective SPI.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Reviewed-by: Hartmut Knaack <knaack.h@gmx.de>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

1 files changed, 476 insertions, 0 deletions

diff --git a/drivers/hwmon/adt7x10.c b/drivers/hwmon/adt7x10.c
new file mode 100644
index 00000000000..84b3dfc1c1c
--- /dev/null
+++ b/drivers/hwmon/adt7x10.c
@@ -0,0 +1,476 @@
+/*
+ * adt7x10.c - Part of lm_sensors, Linux kernel modules for hardware
+ *	 monitoring
+ * This driver handles the ADT7410 and compatible digital temperature sensors.
+ * Hartmut Knaack <knaack.h@gmx.de> 2012-07-22
+ * based on lm75.c by Frodo Looijaard <frodol@dds.nl>
+ * and adt7410.c from iio-staging by Sonic Zhang <sonic.zhang@analog.com>
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/jiffies.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/err.h>
+#include <linux/mutex.h>
+#include <linux/delay.h>
+
+#include "adt7x10.h"
+
+/*
+ * ADT7X10 status
+ */
+#define ADT7X10_STAT_T_LOW		(1 << 4)
+#define ADT7X10_STAT_T_HIGH		(1 << 5)
+#define ADT7X10_STAT_T_CRIT		(1 << 6)
+#define ADT7X10_STAT_NOT_RDY		(1 << 7)
+
+/*
+ * ADT7X10 config
+ */
+#define ADT7X10_FAULT_QUEUE_MASK	(1 << 0 | 1 << 1)
+#define ADT7X10_CT_POLARITY		(1 << 2)
+#define ADT7X10_INT_POLARITY		(1 << 3)
+#define ADT7X10_EVENT_MODE		(1 << 4)
+#define ADT7X10_MODE_MASK		(1 << 5 | 1 << 6)
+#define ADT7X10_FULL			(0 << 5 | 0 << 6)
+#define ADT7X10_PD			(1 << 5 | 1 << 6)
+#define ADT7X10_RESOLUTION		(1 << 7)
+
+/*
+ * ADT7X10 masks
+ */
+#define ADT7X10_T13_VALUE_MASK		0xFFF8
+#define ADT7X10_T_HYST_MASK		0xF
+
+/* straight from the datasheet */
+#define ADT7X10_TEMP_MIN (-55000)
+#define ADT7X10_TEMP_MAX 150000
+
+/* Each client has this additional data */
+struct adt7x10_data {
+	const struct adt7x10_ops *ops;
+	const char		*name;
+	struct device		*hwmon_dev;
+	struct mutex		update_lock;
+	u8			config;
+	u8			oldconfig;
+	bool			valid;		/* true if registers valid */
+	unsigned long		last_updated;	/* In jiffies */
+	s16			temp[4];	/* Register values,
+						   0 = input
+						   1 = high
+						   2 = low
+						   3 = critical */
+	u8			hyst;		/* hysteresis offset */
+};
+
+static int adt7x10_read_byte(struct device *dev, u8 reg)
+{
+	struct adt7x10_data *d = dev_get_drvdata(dev);
+	return d->ops->read_byte(dev, reg);
+}
+
+static int adt7x10_write_byte(struct device *dev, u8 reg, u8 data)
+{
+	struct adt7x10_data *d = dev_get_drvdata(dev);
+	return d->ops->write_byte(dev, reg, data);
+}
+
+static int adt7x10_read_word(struct device *dev, u8 reg)
+{
+	struct adt7x10_data *d = dev_get_drvdata(dev);
+	return d->ops->read_word(dev, reg);
+}
+
+static int adt7x10_write_word(struct device *dev, u8 reg, u16 data)
+{
+	struct adt7x10_data *d = dev_get_drvdata(dev);
+	return d->ops->write_word(dev, reg, data);
+}
+
+static const u8 ADT7X10_REG_TEMP[4] = {
+	ADT7X10_TEMPERATURE,		/* input */
+	ADT7X10_T_ALARM_HIGH,		/* high */
+	ADT7X10_T_ALARM_LOW,		/* low */
+	ADT7X10_T_CRIT,			/* critical */
+};
+
+static int adt7x10_temp_ready(struct device *dev)
+{
+	int i, status;
+
+	for (i = 0; i < 6; i++) {
+		status = adt7x10_read_byte(dev, ADT7X10_STATUS);
+		if (status < 0)
+			return status;
+		if (!(status & ADT7X10_STAT_NOT_RDY))
+			return 0;
+		msleep(60);
+	}
+	return -ETIMEDOUT;
+}
+
+static int adt7x10_update_temp(struct device *dev)
+{
+	struct adt7x10_data *data = dev_get_drvdata(dev);
+	int ret = 0;
+
+	mutex_lock(&data->update_lock);
+
+	if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
+	    || !data->valid) {
+		int temp;
+
+		dev_dbg(dev, "Starting update\n");
+
+		ret = adt7x10_temp_ready(dev); /* check for new value */
+		if (ret)
+			goto abort;
+
+		temp = adt7x10_read_word(dev, ADT7X10_REG_TEMP[0]);
+		if (temp < 0) {
+			ret = temp;
+			dev_dbg(dev, "Failed to read value: reg %d, error %d\n",
+				ADT7X10_REG_TEMP[0], ret);
+			goto abort;
+		}
+		data->temp[0] = temp;
+		data->last_updated = jiffies;
+		data->valid = true;
+	}
+
+abort:
+	mutex_unlock(&data->update_lock);
+	return ret;
+}
+
+static int adt7x10_fill_cache(struct device *dev)
+{
+	struct adt7x10_data *data = dev_get_drvdata(dev);
+	int ret;
+	int i;
+
+	for (i = 1; i < ARRAY_SIZE(data->temp); i++) {
+		ret = adt7x10_read_word(dev, ADT7X10_REG_TEMP[i]);
+		if (ret < 0) {
+			dev_dbg(dev, "Failed to read value: reg %d, error %d\n",
+				ADT7X10_REG_TEMP[i], ret);
+			return ret;
+		}
+		data->temp[i] = ret;
+	}
+
+	ret = adt7x10_read_byte(dev, ADT7X10_T_HYST);
+	if (ret < 0) {
+		dev_dbg(dev, "Failed to read value: reg %d, error %d\n",
+				ADT7X10_T_HYST, ret);
+		return ret;
+	}
+	data->hyst = ret;
+
+	return 0;
+}
+
+static s16 ADT7X10_TEMP_TO_REG(long temp)
+{
+	return DIV_ROUND_CLOSEST(clamp_val(temp, ADT7X10_TEMP_MIN,
+					       ADT7X10_TEMP_MAX) * 128, 1000);
+}
+
+static int ADT7X10_REG_TO_TEMP(struct adt7x10_data *data, s16 reg)
+{
+	/* in 13 bit mode, bits 0-2 are status flags - mask them out */
+	if (!(data->config & ADT7X10_RESOLUTION))
+		reg &= ADT7X10_T13_VALUE_MASK;
+	/*
+	 * temperature is stored in twos complement format, in steps of
+	 * 1/128°C
+	 */
+	return DIV_ROUND_CLOSEST(reg * 1000, 128);
+}
+
+/*-----------------------------------------------------------------------*/
+
+/* sysfs attributes for hwmon */
+
+static ssize_t adt7x10_show_temp(struct device *dev,
+				 struct device_attribute *da,
+				 char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
+	struct adt7x10_data *data = dev_get_drvdata(dev);
+
+
+	if (attr->index == 0) {
+		int ret;
+
+		ret = adt7x10_update_temp(dev);
+		if (ret)
+			return ret;
+	}
+
+	return sprintf(buf, "%d\n", ADT7X10_REG_TO_TEMP(data,
+		       data->temp[attr->index]));
+}
+
+static ssize_t adt7x10_set_temp(struct device *dev,
+				struct device_attribute *da,
+				const char *buf, size_t count)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
+	struct adt7x10_data *data = dev_get_drvdata(dev);
+	int nr = attr->index;
+	long temp;
+	int ret;
+
+	ret = kstrtol(buf, 10, &temp);
+	if (ret)
+		return ret;
+
+	mutex_lock(&data->update_lock);
+	data->temp[nr] = ADT7X10_TEMP_TO_REG(temp);
+	ret = adt7x10_write_word(dev, ADT7X10_REG_TEMP[nr], data->temp[nr]);
+	if (ret)
+		count = ret;
+	mutex_unlock(&data->update_lock);
+	return count;
+}
+
+static ssize_t adt7x10_show_t_hyst(struct device *dev,
+				   struct device_attribute *da,
+				   char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
+	struct adt7x10_data *data = dev_get_drvdata(dev);
+	int nr = attr->index;
+	int hyst;
+
+	hyst = (data->hyst & ADT7X10_T_HYST_MASK) * 1000;
+
+	/*
+	 * hysteresis is stored as a 4 bit offset in the device, convert it
+	 * to an absolute value
+	 */
+	if (nr == 2)	/* min has positive offset, others have negative */
+		hyst = -hyst;
+	return sprintf(buf, "%d\n",
+		       ADT7X10_REG_TO_TEMP(data, data->temp[nr]) - hyst);
+}
+
+static ssize_t adt7x10_set_t_hyst(struct device *dev,
+				  struct device_attribute *da,
+				  const char *buf, size_t count)
+{
+	struct adt7x10_data *data = dev_get_drvdata(dev);
+	int limit, ret;
+	long hyst;
+
+	ret = kstrtol(buf, 10, &hyst);
+	if (ret)
+		return ret;
+	/* convert absolute hysteresis value to a 4 bit delta value */
+	limit = ADT7X10_REG_TO_TEMP(data, data->temp[1]);
+	hyst = clamp_val(hyst, ADT7X10_TEMP_MIN, ADT7X10_TEMP_MAX);
+	data->hyst = clamp_val(DIV_ROUND_CLOSEST(limit - hyst, 1000),
+				   0, ADT7X10_T_HYST_MASK);
+	ret = adt7x10_write_byte(dev, ADT7X10_T_HYST, data->hyst);
+	if (ret)
+		return ret;
+
+	return count;
+}
+
+static ssize_t adt7x10_show_alarm(struct device *dev,
+				  struct device_attribute *da,
+				  char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
+	int ret;
+
+	ret = adt7x10_read_byte(dev, ADT7X10_STATUS);
+	if (ret < 0)
+		return ret;
+
+	return sprintf(buf, "%d\n", !!(ret & attr->index));
+}
+
+static ssize_t adt7x10_show_name(struct device *dev,
+				 struct device_attribute *da,
+				 char *buf)
+{
+	struct adt7x10_data *data = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%s\n", data->name);
+}
+
+static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, adt7x10_show_temp, NULL, 0);
+static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
+			  adt7x10_show_temp, adt7x10_set_temp, 1);
+static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO,
+			  adt7x10_show_temp, adt7x10_set_temp, 2);
+static SENSOR_DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO,
+			  adt7x10_show_temp, adt7x10_set_temp, 3);
+static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO,
+			  adt7x10_show_t_hyst, adt7x10_set_t_hyst, 1);
+static SENSOR_DEVICE_ATTR(temp1_min_hyst, S_IRUGO,
+			  adt7x10_show_t_hyst, NULL, 2);
+static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IRUGO,
+			  adt7x10_show_t_hyst, NULL, 3);
+static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, adt7x10_show_alarm,
+			  NULL, ADT7X10_STAT_T_LOW);
+static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, adt7x10_show_alarm,
+			  NULL, ADT7X10_STAT_T_HIGH);
+static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, adt7x10_show_alarm,
+			  NULL, ADT7X10_STAT_T_CRIT);
+static DEVICE_ATTR(name, S_IRUGO, adt7x10_show_name, NULL);
+
+static struct attribute *adt7x10_attributes[] = {
+	&sensor_dev_attr_temp1_input.dev_attr.attr,
+	&sensor_dev_attr_temp1_max.dev_attr.attr,
+	&sensor_dev_attr_temp1_min.dev_attr.attr,
+	&sensor_dev_attr_temp1_crit.dev_attr.attr,
+	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
+	&sensor_dev_attr_temp1_min_hyst.dev_attr.attr,
+	&sensor_dev_attr_temp1_crit_hyst.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_alarm.dev_attr.attr,
+	NULL
+};
+
+static const struct attribute_group adt7x10_group = {
+	.attrs = adt7x10_attributes,
+};
+
+int adt7x10_probe(struct device *dev, const char *name,
+		  const struct adt7x10_ops *ops)
+{
+	struct adt7x10_data *data;
+	int ret;
+
+	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->ops = ops;
+	data->name = name;
+
+	dev_set_drvdata(dev, data);
+	mutex_init(&data->update_lock);
+
+	/* configure as specified */
+	ret = adt7x10_read_byte(dev, ADT7X10_CONFIG);
+	if (ret < 0) {
+		dev_dbg(dev, "Can't read config? %d\n", ret);
+		return ret;
+	}
+	data->oldconfig = ret;
+
+	/*
+	 * Set to 16 bit resolution, continous conversion and comparator mode.
+	 */
+	data->config = data->oldconfig;
+	data->config &= ~ADT7X10_MODE_MASK;
+	data->config |= ADT7X10_FULL | ADT7X10_RESOLUTION | ADT7X10_EVENT_MODE;
+	if (data->config != data->oldconfig) {
+		ret = adt7x10_write_byte(dev, ADT7X10_CONFIG, data->config);
+		if (ret)
+			return ret;
+	}
+	dev_dbg(dev, "Config %02x\n", data->config);
+
+	ret = adt7x10_fill_cache(dev);
+	if (ret)
+		goto exit_restore;
+
+	/* Register sysfs hooks */
+	ret = sysfs_create_group(&dev->kobj, &adt7x10_group);
+	if (ret)
+		goto exit_restore;
+
+	/*
+	 * The I2C device will already have it's own 'name' attribute, but for
+	 * the SPI device we need to register it. name will only be non NULL if
+	 * the device doesn't register the 'name' attribute on its own.
+	 */
+	if (name) {
+		ret = device_create_file(dev, &dev_attr_name);
+		if (ret)
+			goto exit_remove;
+	}
+
+	data->hwmon_dev = hwmon_device_register(dev);
+	if (IS_ERR(data->hwmon_dev)) {
+		ret = PTR_ERR(data->hwmon_dev);
+		goto exit_remove_name;
+	}
+
+	return 0;
+
+exit_remove_name:
+	if (name)
+		device_remove_file(dev, &dev_attr_name);
+exit_remove:
+	sysfs_remove_group(&dev->kobj, &adt7x10_group);
+exit_restore:
+	adt7x10_write_byte(dev, ADT7X10_CONFIG, data->oldconfig);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(adt7x10_probe);
+
+int adt7x10_remove(struct device *dev)
+{
+	struct adt7x10_data *data = dev_get_drvdata(dev);
+
+	hwmon_device_unregister(data->hwmon_dev);
+	if (data->name)
+		device_remove_file(dev, &dev_attr_name);
+	sysfs_remove_group(&dev->kobj, &adt7x10_group);
+	if (data->oldconfig != data->config)
+		adt7x10_write_byte(dev, ADT7X10_CONFIG, data->oldconfig);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(adt7x10_remove);
+
+#ifdef CONFIG_PM_SLEEP
+
+static int adt7x10_suspend(struct device *dev)
+{
+	struct adt7x10_data *data = dev_get_drvdata(dev);
+
+	return adt7x10_write_byte(dev, ADT7X10_CONFIG,
+		data->config | ADT7X10_PD);
+}
+
+static int adt7x10_resume(struct device *dev)
+{
+	struct adt7x10_data *data = dev_get_drvdata(dev);
+
+	return adt7x10_write_byte(dev, ADT7X10_CONFIG, data->config);
+}
+
+SIMPLE_DEV_PM_OPS(adt7x10_dev_pm_ops, adt7x10_suspend, adt7x10_resume);
+EXPORT_SYMBOL_GPL(adt7x10_dev_pm_ops);
+
+#endif /* CONFIG_PM_SLEEP */
+
+MODULE_AUTHOR("Hartmut Knaack");
+MODULE_DESCRIPTION("ADT7410/ADT7420, ADT7310/ADT7320 common code");
+MODULE_LICENSE("GPL");