hwmon: New max6650 driver
This driver supports the Maxim MAX6650 and MAX6651 fan speed
monitoring and control chips.
Signed-off-by: Hans J. Koch <hjk@linutronix.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
diff --git a/Documentation/hwmon/max6650 b/Documentation/hwmon/max6650
new file mode 100644
index 0000000..8be7beb
--- /dev/null
+++ b/Documentation/hwmon/max6650
@@ -0,0 +1,53 @@
+Kernel driver max6650
+=====================
+
+Supported chips:
+ * Maxim 6650 / 6651
+ Prefix: 'max6650'
+ Addresses scanned: I2C 0x1b, 0x1f, 0x48, 0x4b
+ Datasheet: http://pdfserv.maxim-ic.com/en/ds/MAX6650-MAX6651.pdf
+
+Authors:
+ Hans J. Koch <hjk@linutronix.de>
+ John Morris <john.morris@spirentcom.com>
+ Claus Gindhart <claus.gindhart@kontron.com>
+
+Description
+-----------
+
+This driver implements support for the Maxim 6650/6651
+
+The 2 devices are very similar, but the Maxim 6550 has a reduced feature
+set, e.g. only one fan-input, instead of 4 for the 6651.
+
+The driver is not able to distinguish between the 2 devices.
+
+The driver provides the following sensor accesses in sysfs:
+
+fan1_input ro fan tachometer speed in RPM
+fan2_input ro "
+fan3_input ro "
+fan4_input ro "
+fan1_target rw desired fan speed in RPM (closed loop mode only)
+pwm1_enable rw regulator mode, 0=full on, 1=open loop, 2=closed loop
+pwm1 rw relative speed (0-255), 255=max. speed.
+ Used in open loop mode only.
+fan1_div rw sets the speed range the inputs can handle. Legal
+ values are 1, 2, 4, and 8. Use lower values for
+ faster fans.
+
+Module parameters
+-----------------
+
+If your board has a BIOS that initializes the MAX6650/6651 correctly, you can
+simply load your module without parameters. It won't touch the configuration
+registers then. If your board BIOS doesn't initialize the chip, or you want
+different settings, you can set the following parameters:
+
+voltage_12V: 5=5V fan, 12=12V fan, 0=don't change
+prescaler: Possible values are 1,2,4,8,16, or 0 for don't change
+clock: The clock frequency in Hz of the chip the driver should assume [254000]
+
+Please have a look at the MAX6650/6651 data sheet and make sure that you fully
+understand the meaning of these parameters before you attempt to change them.
+
diff --git a/MAINTAINERS b/MAINTAINERS
index 6d665ac..a328862 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2304,6 +2304,12 @@
L: linux-fbdev-devel@lists.sourceforge.net (subscribers-only)
S: Maintained
+MAX6650 HARDWARE MONITOR AND FAN CONTROLLER DRIVER
+P: Hans J. Koch
+M: hjk@linutronix.de
+L: lm-sensors@lm-sensors.org
+S: Maintained
+
MEGARAID SCSI DRIVERS
P: Neela Syam Kolli
M: Neela.Kolli@engenio.com
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 6362d02..d89bd5e 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -375,6 +375,16 @@
This driver can also be built as a module. If so, the module
will be called max1619.
+config SENSORS_MAX6650
+ tristate "Maxim MAX6650 sensor chip"
+ depends on HWMON && I2C && EXPERIMENTAL
+ help
+ If you say yes here you get support for the MAX6650 / MAX6651
+ sensor chips.
+
+ This driver can also be built as a module. If so, the module
+ will be called max6650.
+
config SENSORS_PC87360
tristate "National Semiconductor PC87360 family"
depends on HWMON && I2C && EXPERIMENTAL
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 4165c27..bbbe86b 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -43,6 +43,7 @@
obj-$(CONFIG_SENSORS_LM90) += lm90.o
obj-$(CONFIG_SENSORS_LM92) += lm92.o
obj-$(CONFIG_SENSORS_MAX1619) += max1619.o
+obj-$(CONFIG_SENSORS_MAX6650) += max6650.o
obj-$(CONFIG_SENSORS_PC87360) += pc87360.o
obj-$(CONFIG_SENSORS_PC87427) += pc87427.o
obj-$(CONFIG_SENSORS_SIS5595) += sis5595.o
diff --git a/drivers/hwmon/max6650.c b/drivers/hwmon/max6650.c
new file mode 100644
index 0000000..8415664
--- /dev/null
+++ b/drivers/hwmon/max6650.c
@@ -0,0 +1,693 @@
+/*
+ * max6650.c - Part of lm_sensors, Linux kernel modules for hardware
+ * monitoring.
+ *
+ * (C) 2007 by Hans J. Koch <hjk@linutronix.de>
+ *
+ * based on code written by John Morris <john.morris@spirentcom.com>
+ * Copyright (c) 2003 Spirent Communications
+ * and Claus Gindhart <claus.gindhart@kontron.com>
+ *
+ * This module has only been tested with the MAX6650 chip. It should
+ * also work with the MAX6651. It does not distinguish max6650 and max6651
+ * chips.
+ *
+ * Tha datasheet was last seen at:
+ *
+ * http://pdfserv.maxim-ic.com/en/ds/MAX6650-MAX6651.pdf
+ *
+ * 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/i2c.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/err.h>
+
+/*
+ * Addresses to scan. There are four disjoint possibilities, by pin config.
+ */
+
+static unsigned short normal_i2c[] = {0x1b, 0x1f, 0x48, 0x4b, I2C_CLIENT_END};
+
+/*
+ * Insmod parameters
+ */
+
+/* fan_voltage: 5=5V fan, 12=12V fan, 0=don't change */
+static int fan_voltage;
+/* prescaler: Possible values are 1, 2, 4, 8, 16 or 0 for don't change */
+static int prescaler;
+/* clock: The clock frequency of the chip the driver should assume */
+static int clock = 254000;
+
+module_param(fan_voltage, int, S_IRUGO);
+module_param(prescaler, int, S_IRUGO);
+module_param(clock, int, S_IRUGO);
+
+I2C_CLIENT_INSMOD_1(max6650);
+
+/*
+ * MAX 6650/6651 registers
+ */
+
+#define MAX6650_REG_SPEED 0x00
+#define MAX6650_REG_CONFIG 0x02
+#define MAX6650_REG_GPIO_DEF 0x04
+#define MAX6650_REG_DAC 0x06
+#define MAX6650_REG_ALARM_EN 0x08
+#define MAX6650_REG_ALARM 0x0A
+#define MAX6650_REG_TACH0 0x0C
+#define MAX6650_REG_TACH1 0x0E
+#define MAX6650_REG_TACH2 0x10
+#define MAX6650_REG_TACH3 0x12
+#define MAX6650_REG_GPIO_STAT 0x14
+#define MAX6650_REG_COUNT 0x16
+
+/*
+ * Config register bits
+ */
+
+#define MAX6650_CFG_V12 0x08
+#define MAX6650_CFG_PRESCALER_MASK 0x07
+#define MAX6650_CFG_PRESCALER_2 0x01
+#define MAX6650_CFG_PRESCALER_4 0x02
+#define MAX6650_CFG_PRESCALER_8 0x03
+#define MAX6650_CFG_PRESCALER_16 0x04
+#define MAX6650_CFG_MODE_MASK 0x30
+#define MAX6650_CFG_MODE_ON 0x00
+#define MAX6650_CFG_MODE_OFF 0x10
+#define MAX6650_CFG_MODE_CLOSED_LOOP 0x20
+#define MAX6650_CFG_MODE_OPEN_LOOP 0x30
+#define MAX6650_COUNT_MASK 0x03
+
+/* Minimum and maximum values of the FAN-RPM */
+#define FAN_RPM_MIN 240
+#define FAN_RPM_MAX 30000
+
+#define DIV_FROM_REG(reg) (1 << (reg & 7))
+
+static int max6650_attach_adapter(struct i2c_adapter *adapter);
+static int max6650_detect(struct i2c_adapter *adapter, int address, int kind);
+static int max6650_init_client(struct i2c_client *client);
+static int max6650_detach_client(struct i2c_client *client);
+static struct max6650_data *max6650_update_device(struct device *dev);
+
+/*
+ * Driver data (common to all clients)
+ */
+
+static struct i2c_driver max6650_driver = {
+ .driver = {
+ .name = "max6650",
+ },
+ .attach_adapter = max6650_attach_adapter,
+ .detach_client = max6650_detach_client,
+};
+
+/*
+ * Client data (each client gets its own)
+ */
+
+struct max6650_data
+{
+ struct i2c_client client;
+ struct class_device *class_dev;
+ struct mutex update_lock;
+ char valid; /* zero until following fields are valid */
+ unsigned long last_updated; /* in jiffies */
+
+ /* register values */
+ u8 speed;
+ u8 config;
+ u8 tach[4];
+ u8 count;
+ u8 dac;
+};
+
+static ssize_t get_fan(struct device *dev, struct device_attribute *devattr,
+ char *buf)
+{
+ struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+ struct max6650_data *data = max6650_update_device(dev);
+ int rpm;
+
+ /*
+ * Calculation details:
+ *
+ * Each tachometer counts over an interval given by the "count"
+ * register (0.25, 0.5, 1 or 2 seconds). This module assumes
+ * that the fans produce two pulses per revolution (this seems
+ * to be the most common).
+ */
+
+ rpm = ((data->tach[attr->index] * 120) / DIV_FROM_REG(data->count));
+ return sprintf(buf, "%d\n", rpm);
+}
+
+/*
+ * Set the fan speed to the specified RPM (or read back the RPM setting).
+ * This works in closed loop mode only. Use pwm1 for open loop speed setting.
+ *
+ * The MAX6650/1 will automatically control fan speed when in closed loop
+ * mode.
+ *
+ * Assumptions:
+ *
+ * 1) The MAX6650/1 internal 254kHz clock frequency is set correctly. Use
+ * the clock module parameter if you need to fine tune this.
+ *
+ * 2) The prescaler (low three bits of the config register) has already
+ * been set to an appropriate value. Use the prescaler module parameter
+ * if your BIOS doesn't initialize the chip properly.
+ *
+ * The relevant equations are given on pages 21 and 22 of the datasheet.
+ *
+ * From the datasheet, the relevant equation when in regulation is:
+ *
+ * [fCLK / (128 x (KTACH + 1))] = 2 x FanSpeed / KSCALE
+ *
+ * where:
+ *
+ * fCLK is the oscillator frequency (either the 254kHz internal
+ * oscillator or the externally applied clock)
+ *
+ * KTACH is the value in the speed register
+ *
+ * FanSpeed is the speed of the fan in rps
+ *
+ * KSCALE is the prescaler value (1, 2, 4, 8, or 16)
+ *
+ * When reading, we need to solve for FanSpeed. When writing, we need to
+ * solve for KTACH.
+ *
+ * Note: this tachometer is completely separate from the tachometers
+ * used to measure the fan speeds. Only one fan's speed (fan1) is
+ * controlled.
+ */
+
+static ssize_t get_target(struct device *dev, struct device_attribute *devattr,
+ char *buf)
+{
+ struct max6650_data *data = max6650_update_device(dev);
+ int kscale, ktach, rpm;
+
+ /*
+ * Use the datasheet equation:
+ *
+ * FanSpeed = KSCALE x fCLK / [256 x (KTACH + 1)]
+ *
+ * then multiply by 60 to give rpm.
+ */
+
+ kscale = DIV_FROM_REG(data->config);
+ ktach = data->speed;
+ rpm = 60 * kscale * clock / (256 * (ktach + 1));
+ return sprintf(buf, "%d\n", rpm);
+}
+
+static ssize_t set_target(struct device *dev, struct device_attribute *devattr,
+ const char *buf, size_t count)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct max6650_data *data = i2c_get_clientdata(client);
+ int rpm = simple_strtoul(buf, NULL, 10);
+ int kscale, ktach;
+
+ rpm = SENSORS_LIMIT(rpm, FAN_RPM_MIN, FAN_RPM_MAX);
+
+ /*
+ * Divide the required speed by 60 to get from rpm to rps, then
+ * use the datasheet equation:
+ *
+ * KTACH = [(fCLK x KSCALE) / (256 x FanSpeed)] - 1
+ */
+
+ mutex_lock(&data->update_lock);
+
+ kscale = DIV_FROM_REG(data->config);
+ ktach = ((clock * kscale) / (256 * rpm / 60)) - 1;
+ if (ktach < 0)
+ ktach = 0;
+ if (ktach > 255)
+ ktach = 255;
+ data->speed = ktach;
+
+ i2c_smbus_write_byte_data(client, MAX6650_REG_SPEED, data->speed);
+
+ mutex_unlock(&data->update_lock);
+
+ return count;
+}
+
+/*
+ * Get/set the fan speed in open loop mode using pwm1 sysfs file.
+ * Speed is given as a relative value from 0 to 255, where 255 is maximum
+ * speed. Note that this is done by writing directly to the chip's DAC,
+ * it won't change the closed loop speed set by fan1_target.
+ * Also note that due to rounding errors it is possible that you don't read
+ * back exactly the value you have set.
+ */
+
+static ssize_t get_pwm(struct device *dev, struct device_attribute *devattr,
+ char *buf)
+{
+ int pwm;
+ struct max6650_data *data = max6650_update_device(dev);
+
+ /* Useful range for dac is 0-180 for 12V fans and 0-76 for 5V fans.
+ Lower DAC values mean higher speeds. */
+ if (data->config & MAX6650_CFG_V12)
+ pwm = 255 - (255 * (int)data->dac)/180;
+ else
+ pwm = 255 - (255 * (int)data->dac)/76;
+
+ if (pwm < 0)
+ pwm = 0;
+
+ return sprintf(buf, "%d\n", pwm);
+}
+
+static ssize_t set_pwm(struct device *dev, struct device_attribute *devattr,
+ const char *buf, size_t count)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct max6650_data *data = i2c_get_clientdata(client);
+ int pwm = simple_strtoul(buf, NULL, 10);
+
+ pwm = SENSORS_LIMIT(pwm, 0, 255);
+
+ mutex_lock(&data->update_lock);
+
+ if (data->config & MAX6650_CFG_V12)
+ data->dac = 180 - (180 * pwm)/255;
+ else
+ data->dac = 76 - (76 * pwm)/255;
+
+ i2c_smbus_write_byte_data(client, MAX6650_REG_DAC, data->dac);
+
+ mutex_unlock(&data->update_lock);
+
+ return count;
+}
+
+/*
+ * Get/Set controller mode:
+ * Possible values:
+ * 0 = Fan always on
+ * 1 = Open loop, Voltage is set according to speed, not regulated.
+ * 2 = Closed loop, RPM for all fans regulated by fan1 tachometer
+ */
+
+static ssize_t get_enable(struct device *dev, struct device_attribute *devattr,
+ char *buf)
+{
+ struct max6650_data *data = max6650_update_device(dev);
+ int mode = (data->config & MAX6650_CFG_MODE_MASK) >> 4;
+ int sysfs_modes[4] = {0, 1, 2, 1};
+
+ return sprintf(buf, "%d\n", sysfs_modes[mode]);
+}
+
+static ssize_t set_enable(struct device *dev, struct device_attribute *devattr,
+ const char *buf, size_t count)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct max6650_data *data = i2c_get_clientdata(client);
+ int mode = simple_strtoul(buf, NULL, 10);
+ int max6650_modes[3] = {0, 3, 2};
+
+ if ((mode < 0)||(mode > 2)) {
+ dev_err(&client->dev,
+ "illegal value for pwm1_enable (%d)\n", mode);
+ return -EINVAL;
+ }
+
+ mutex_lock(&data->update_lock);
+
+ data->config = i2c_smbus_read_byte_data(client, MAX6650_REG_CONFIG);
+ data->config = (data->config & ~MAX6650_CFG_MODE_MASK)
+ | (max6650_modes[mode] << 4);
+
+ i2c_smbus_write_byte_data(client, MAX6650_REG_CONFIG, data->config);
+
+ mutex_unlock(&data->update_lock);
+
+ return count;
+}
+
+/*
+ * Read/write functions for fan1_div sysfs file. The MAX6650 has no such
+ * divider. We handle this by converting between divider and counttime:
+ *
+ * (counttime == k) <==> (divider == 2^k), k = 0, 1, 2, or 3
+ *
+ * Lower values of k allow to connect a faster fan without the risk of
+ * counter overflow. The price is lower resolution. You can also set counttime
+ * using the module parameter. Note that the module parameter "prescaler" also
+ * influences the behaviour. Unfortunately, there's no sysfs attribute
+ * defined for that. See the data sheet for details.
+ */
+
+static ssize_t get_div(struct device *dev, struct device_attribute *devattr,
+ char *buf)
+{
+ struct max6650_data *data = max6650_update_device(dev);
+
+ return sprintf(buf, "%d\n", DIV_FROM_REG(data->count));
+}
+
+static ssize_t set_div(struct device *dev, struct device_attribute *devattr,
+ const char *buf, size_t count)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct max6650_data *data = i2c_get_clientdata(client);
+ int div = simple_strtoul(buf, NULL, 10);
+
+ mutex_lock(&data->update_lock);
+ switch (div) {
+ case 1:
+ data->count = 0;
+ break;
+ case 2:
+ data->count = 1;
+ break;
+ case 4:
+ data->count = 2;
+ break;
+ case 8:
+ data->count = 3;
+ break;
+ default:
+ dev_err(&client->dev,
+ "illegal value for fan divider (%d)\n", div);
+ return -EINVAL;
+ }
+
+ i2c_smbus_write_byte_data(client, MAX6650_REG_COUNT, data->count);
+ mutex_unlock(&data->update_lock);
+
+ return count;
+}
+
+static SENSOR_DEVICE_ATTR(fan1_input, S_IRUGO, get_fan, NULL, 0);
+static SENSOR_DEVICE_ATTR(fan2_input, S_IRUGO, get_fan, NULL, 1);
+static SENSOR_DEVICE_ATTR(fan3_input, S_IRUGO, get_fan, NULL, 2);
+static SENSOR_DEVICE_ATTR(fan4_input, S_IRUGO, get_fan, NULL, 3);
+static DEVICE_ATTR(fan1_target, S_IWUSR | S_IRUGO, get_target, set_target);
+static DEVICE_ATTR(fan1_div, S_IWUSR | S_IRUGO, get_div, set_div);
+static DEVICE_ATTR(pwm1_enable, S_IWUSR | S_IRUGO, get_enable, set_enable);
+static DEVICE_ATTR(pwm1, S_IWUSR | S_IRUGO, get_pwm, set_pwm);
+
+
+static struct attribute *max6650_attrs[] = {
+ &sensor_dev_attr_fan1_input.dev_attr.attr,
+ &sensor_dev_attr_fan2_input.dev_attr.attr,
+ &sensor_dev_attr_fan3_input.dev_attr.attr,
+ &sensor_dev_attr_fan4_input.dev_attr.attr,
+ &dev_attr_fan1_target.attr,
+ &dev_attr_fan1_div.attr,
+ &dev_attr_pwm1_enable.attr,
+ &dev_attr_pwm1.attr,
+ NULL
+};
+
+static struct attribute_group max6650_attr_grp = {
+ .attrs = max6650_attrs,
+};
+
+/*
+ * Real code
+ */
+
+static int max6650_attach_adapter(struct i2c_adapter *adapter)
+{
+ if (!(adapter->class & I2C_CLASS_HWMON)) {
+ dev_dbg(&adapter->dev,
+ "FATAL: max6650_attach_adapter class HWMON not set\n");
+ return 0;
+ }
+
+ return i2c_probe(adapter, &addr_data, max6650_detect);
+}
+
+/*
+ * The following function does more than just detection. If detection
+ * succeeds, it also registers the new chip.
+ */
+
+static int max6650_detect(struct i2c_adapter *adapter, int address, int kind)
+{
+ struct i2c_client *client;
+ struct max6650_data *data;
+ int err = -ENODEV;
+
+ dev_dbg(&adapter->dev, "max6650_detect called, kind = %d\n", kind);
+
+ if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) {
+ dev_dbg(&adapter->dev, "max6650: I2C bus doesn't support "
+ "byte read mode, skipping.\n");
+ return 0;
+ }
+
+ if (!(data = kzalloc(sizeof(struct max6650_data), GFP_KERNEL))) {
+ dev_err(&adapter->dev, "max6650: out of memory.\n");
+ return -ENOMEM;
+ }
+
+ client = &data->client;
+ i2c_set_clientdata(client, data);
+ client->addr = address;
+ client->adapter = adapter;
+ client->driver = &max6650_driver;
+
+ /*
+ * Now we do the remaining detection. A negative kind means that
+ * the driver was loaded with no force parameter (default), so we
+ * must both detect and identify the chip (actually there is only
+ * one possible kind of chip for now, max6650). A zero kind means that
+ * the driver was loaded with the force parameter, the detection
+ * step shall be skipped. A positive kind means that the driver
+ * was loaded with the force parameter and a given kind of chip is
+ * requested, so both the detection and the identification steps
+ * are skipped.
+ *
+ * Currently I can find no way to distinguish between a MAX6650 and
+ * a MAX6651. This driver has only been tried on the former.
+ */
+
+ if ((kind < 0) &&
+ ( (i2c_smbus_read_byte_data(client, MAX6650_REG_CONFIG) & 0xC0)
+ ||(i2c_smbus_read_byte_data(client, MAX6650_REG_GPIO_STAT) & 0xE0)
+ ||(i2c_smbus_read_byte_data(client, MAX6650_REG_ALARM_EN) & 0xE0)
+ ||(i2c_smbus_read_byte_data(client, MAX6650_REG_ALARM) & 0xE0)
+ ||(i2c_smbus_read_byte_data(client, MAX6650_REG_COUNT) & 0xFC))) {
+ dev_dbg(&adapter->dev,
+ "max6650: detection failed at 0x%02x.\n", address);
+ goto err_free;
+ }
+
+ dev_info(&adapter->dev, "max6650: chip found at 0x%02x.\n", address);
+
+ strlcpy(client->name, "max6650", I2C_NAME_SIZE);
+ mutex_init(&data->update_lock);
+
+ if ((err = i2c_attach_client(client))) {
+ dev_err(&adapter->dev, "max6650: failed to attach client.\n");
+ goto err_free;
+ }
+
+ /*
+ * Initialize the max6650 chip
+ */
+ if (max6650_init_client(client))
+ goto err_detach;
+
+ err = sysfs_create_group(&client->dev.kobj, &max6650_attr_grp);
+ if (err)
+ goto err_detach;
+
+ data->class_dev = hwmon_device_register(&client->dev);
+ if (!IS_ERR(data->class_dev))
+ return 0;
+
+ err = PTR_ERR(data->class_dev);
+ dev_err(&client->dev, "error registering hwmon device.\n");
+ sysfs_remove_group(&client->dev.kobj, &max6650_attr_grp);
+err_detach:
+ i2c_detach_client(client);
+err_free:
+ kfree(data);
+ return err;
+}
+
+static int max6650_detach_client(struct i2c_client *client)
+{
+ struct max6650_data *data = i2c_get_clientdata(client);
+ int err;
+
+ sysfs_remove_group(&client->dev.kobj, &max6650_attr_grp);
+ hwmon_device_unregister(data->class_dev);
+ err = i2c_detach_client(client);
+ if (!err)
+ kfree(data);
+ return err;
+}
+
+static int max6650_init_client(struct i2c_client *client)
+{
+ struct max6650_data *data = i2c_get_clientdata(client);
+ int config;
+ int err = -EIO;
+
+ config = i2c_smbus_read_byte_data(client, MAX6650_REG_CONFIG);
+
+ if (config < 0) {
+ dev_err(&client->dev, "Error reading config, aborting.\n");
+ return err;
+ }
+
+ switch (fan_voltage) {
+ case 0:
+ break;
+ case 5:
+ config &= ~MAX6650_CFG_V12;
+ break;
+ case 12:
+ config |= MAX6650_CFG_V12;
+ break;
+ default:
+ dev_err(&client->dev,
+ "illegal value for fan_voltage (%d)\n",
+ fan_voltage);
+ }
+
+ dev_info(&client->dev, "Fan voltage is set to %dV.\n",
+ (config & MAX6650_CFG_V12) ? 12 : 5);
+
+ switch (prescaler) {
+ case 0:
+ break;
+ case 1:
+ config &= ~MAX6650_CFG_PRESCALER_MASK;
+ break;
+ case 2:
+ config = (config & ~MAX6650_CFG_PRESCALER_MASK)
+ | MAX6650_CFG_PRESCALER_2;
+ break;
+ case 4:
+ config = (config & ~MAX6650_CFG_PRESCALER_MASK)
+ | MAX6650_CFG_PRESCALER_4;
+ break;
+ case 8:
+ config = (config & ~MAX6650_CFG_PRESCALER_MASK)
+ | MAX6650_CFG_PRESCALER_8;
+ break;
+ case 16:
+ config = (config & ~MAX6650_CFG_PRESCALER_MASK)
+ | MAX6650_CFG_PRESCALER_16;
+ break;
+ default:
+ dev_err(&client->dev,
+ "illegal value for prescaler (%d)\n",
+ prescaler);
+ }
+
+ dev_info(&client->dev, "Prescaler is set to %d.\n",
+ 1 << (config & MAX6650_CFG_PRESCALER_MASK));
+
+ /* If mode is set to "full off", we change it to "open loop" and
+ * set DAC to 255, which has the same effect. We do this because
+ * there's no "full off" mode defined in hwmon specifcations.
+ */
+
+ if ((config & MAX6650_CFG_MODE_MASK) == MAX6650_CFG_MODE_OFF) {
+ dev_dbg(&client->dev, "Change mode to open loop, full off.\n");
+ config = (config & ~MAX6650_CFG_MODE_MASK)
+ | MAX6650_CFG_MODE_OPEN_LOOP;
+ if (i2c_smbus_write_byte_data(client, MAX6650_REG_DAC, 255)) {
+ dev_err(&client->dev, "DAC write error, aborting.\n");
+ return err;
+ }
+ }
+
+ if (i2c_smbus_write_byte_data(client, MAX6650_REG_CONFIG, config)) {
+ dev_err(&client->dev, "Config write error, aborting.\n");
+ return err;
+ }
+
+ data->config = config;
+ data->count = i2c_smbus_read_byte_data(client, MAX6650_REG_COUNT);
+
+ return 0;
+}
+
+static const u8 tach_reg[] = {
+ MAX6650_REG_TACH0,
+ MAX6650_REG_TACH1,
+ MAX6650_REG_TACH2,
+ MAX6650_REG_TACH3,
+};
+
+static struct max6650_data *max6650_update_device(struct device *dev)
+{
+ int i;
+ struct i2c_client *client = to_i2c_client(dev);
+ struct max6650_data *data = i2c_get_clientdata(client);
+
+ mutex_lock(&data->update_lock);
+
+ if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
+ data->speed = i2c_smbus_read_byte_data(client,
+ MAX6650_REG_SPEED);
+ data->config = i2c_smbus_read_byte_data(client,
+ MAX6650_REG_CONFIG);
+ for (i = 0; i < 4; i++) {
+ data->tach[i] = i2c_smbus_read_byte_data(client,
+ tach_reg[i]);
+ }
+ data->count = i2c_smbus_read_byte_data(client,
+ MAX6650_REG_COUNT);
+ data->dac = i2c_smbus_read_byte_data(client, MAX6650_REG_DAC);
+
+ data->last_updated = jiffies;
+ data->valid = 1;
+ }
+
+ mutex_unlock(&data->update_lock);
+
+ return data;
+}
+
+static int __init sensors_max6650_init(void)
+{
+ return i2c_add_driver(&max6650_driver);
+}
+
+static void __exit sensors_max6650_exit(void)
+{
+ i2c_del_driver(&max6650_driver);
+}
+
+MODULE_AUTHOR("Hans J. Koch");
+MODULE_DESCRIPTION("MAX6650 sensor driver");
+MODULE_LICENSE("GPL");
+
+module_init(sensors_max6650_init);
+module_exit(sensors_max6650_exit);
