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Diffstat (limited to '')
| -rw-r--r-- | drivers/hwmon/max6650.c | 758 |
1 files changed, 758 insertions, 0 deletions
diff --git a/drivers/hwmon/max6650.c b/drivers/hwmon/max6650.c new file mode 100644 index 000000000..65be4b19f --- /dev/null +++ b/drivers/hwmon/max6650.c @@ -0,0 +1,758 @@ +/* + * max6650.c - Part of lm_sensors, Linux kernel modules for hardware + * monitoring. + * + * (C) 2007 by Hans J. Koch <hjk@hansjkoch.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. + * + * The 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> +#include <linux/of_device.h> + +/* + * 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 (max6651 can be clocked externally) */ +static int clock = 254000; + +module_param(fan_voltage, int, S_IRUGO); +module_param(prescaler, int, S_IRUGO); +module_param(clock, int, S_IRUGO); + +/* + * 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 + +/* + * Alarm status register bits + */ + +#define MAX6650_ALRM_MAX 0x01 +#define MAX6650_ALRM_MIN 0x02 +#define MAX6650_ALRM_TACH 0x04 +#define MAX6650_ALRM_GPIO1 0x08 +#define MAX6650_ALRM_GPIO2 0x10 + +/* 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)) + +/* + * Client data (each client gets its own) + */ + +struct max6650_data { + struct i2c_client *client; + const struct attribute_group *groups[3]; + struct mutex update_lock; + int nr_fans; + 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; + u8 alarm; +}; + +static const u8 tach_reg[] = { + MAX6650_REG_TACH0, + MAX6650_REG_TACH1, + MAX6650_REG_TACH2, + MAX6650_REG_TACH3, +}; + +static const struct of_device_id max6650_dt_match[] = { + { + .compatible = "maxim,max6650", + .data = (void *)1 + }, + { + .compatible = "maxim,max6651", + .data = (void *)4 + }, + { }, +}; +MODULE_DEVICE_TABLE(of, max6650_dt_match); + +static struct max6650_data *max6650_update_device(struct device *dev) +{ + struct max6650_data *data = dev_get_drvdata(dev); + struct i2c_client *client = data->client; + int i; + + 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 < data->nr_fans; 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); + + /* + * Alarms are cleared on read in case the condition that + * caused the alarm is removed. Keep the value latched here + * for providing the register through different alarm files. + */ + data->alarm |= i2c_smbus_read_byte_data(client, + MAX6650_REG_ALARM); + + data->last_updated = jiffies; + data->valid = 1; + } + + mutex_unlock(&data->update_lock); + + return data; +} + +/* + * Change the operating mode of the chip (if needed). + * mode is one of the MAX6650_CFG_MODE_* values. + */ +static int max6650_set_operating_mode(struct max6650_data *data, u8 mode) +{ + int result; + u8 config = data->config; + + if (mode == (config & MAX6650_CFG_MODE_MASK)) + return 0; + + config = (config & ~MAX6650_CFG_MODE_MASK) | mode; + + result = i2c_smbus_write_byte_data(data->client, MAX6650_REG_CONFIG, + config); + if (result < 0) + return result; + + data->config = config; + + return 0; +} + +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 fan1_target_show(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 int max6650_set_target(struct max6650_data *data, unsigned long rpm) +{ + int kscale, ktach; + + if (rpm == 0) + return max6650_set_operating_mode(data, MAX6650_CFG_MODE_OFF); + + rpm = clamp_val(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 + */ + + 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; + + return i2c_smbus_write_byte_data(data->client, MAX6650_REG_SPEED, + data->speed); +} + +static ssize_t fan1_target_store(struct device *dev, + struct device_attribute *devattr, + const char *buf, size_t count) +{ + struct max6650_data *data = dev_get_drvdata(dev); + unsigned long rpm; + int err; + + err = kstrtoul(buf, 10, &rpm); + if (err) + return err; + + mutex_lock(&data->update_lock); + + err = max6650_set_target(data, rpm); + + mutex_unlock(&data->update_lock); + + if (err < 0) + return err; + + 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 pwm1_show(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 pwm1_store(struct device *dev, + struct device_attribute *devattr, const char *buf, + size_t count) +{ + struct max6650_data *data = dev_get_drvdata(dev); + struct i2c_client *client = data->client; + unsigned long pwm; + int err; + + err = kstrtoul(buf, 10, &pwm); + if (err) + return err; + + pwm = clamp_val(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; + err = i2c_smbus_write_byte_data(client, MAX6650_REG_DAC, data->dac); + + mutex_unlock(&data->update_lock); + + return err < 0 ? err : 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 + * 3 = Fan off + */ +static ssize_t pwm1_enable_show(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, 3, 2, 1}; + + return sprintf(buf, "%d\n", sysfs_modes[mode]); +} + +static ssize_t pwm1_enable_store(struct device *dev, + struct device_attribute *devattr, + const char *buf, size_t count) +{ + struct max6650_data *data = dev_get_drvdata(dev); + unsigned long mode; + int err; + const u8 max6650_modes[] = { + MAX6650_CFG_MODE_ON, + MAX6650_CFG_MODE_OPEN_LOOP, + MAX6650_CFG_MODE_CLOSED_LOOP, + MAX6650_CFG_MODE_OFF, + }; + + err = kstrtoul(buf, 10, &mode); + if (err) + return err; + + if (mode >= ARRAY_SIZE(max6650_modes)) + return -EINVAL; + + mutex_lock(&data->update_lock); + + max6650_set_operating_mode(data, max6650_modes[mode]); + + 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 fan1_div_show(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 fan1_div_store(struct device *dev, + struct device_attribute *devattr, + const char *buf, size_t count) +{ + struct max6650_data *data = dev_get_drvdata(dev); + struct i2c_client *client = data->client; + unsigned long div; + int err; + + err = kstrtoul(buf, 10, &div); + if (err) + return err; + + 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: + mutex_unlock(&data->update_lock); + return -EINVAL; + } + + i2c_smbus_write_byte_data(client, MAX6650_REG_COUNT, data->count); + mutex_unlock(&data->update_lock); + + return count; +} + +/* + * Get alarm stati: + * Possible values: + * 0 = no alarm + * 1 = alarm + */ + +static ssize_t get_alarm(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); + struct i2c_client *client = data->client; + int alarm = 0; + + if (data->alarm & attr->index) { + mutex_lock(&data->update_lock); + alarm = 1; + data->alarm &= ~attr->index; + data->alarm |= i2c_smbus_read_byte_data(client, + MAX6650_REG_ALARM); + mutex_unlock(&data->update_lock); + } + + return sprintf(buf, "%d\n", alarm); +} + +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_RW(fan1_target); +static DEVICE_ATTR_RW(fan1_div); +static DEVICE_ATTR_RW(pwm1_enable); +static DEVICE_ATTR_RW(pwm1); +static SENSOR_DEVICE_ATTR(fan1_max_alarm, S_IRUGO, get_alarm, NULL, + MAX6650_ALRM_MAX); +static SENSOR_DEVICE_ATTR(fan1_min_alarm, S_IRUGO, get_alarm, NULL, + MAX6650_ALRM_MIN); +static SENSOR_DEVICE_ATTR(fan1_fault, S_IRUGO, get_alarm, NULL, + MAX6650_ALRM_TACH); +static SENSOR_DEVICE_ATTR(gpio1_alarm, S_IRUGO, get_alarm, NULL, + MAX6650_ALRM_GPIO1); +static SENSOR_DEVICE_ATTR(gpio2_alarm, S_IRUGO, get_alarm, NULL, + MAX6650_ALRM_GPIO2); + +static umode_t max6650_attrs_visible(struct kobject *kobj, struct attribute *a, + int n) +{ + struct device *dev = container_of(kobj, struct device, kobj); + struct max6650_data *data = dev_get_drvdata(dev); + struct i2c_client *client = data->client; + u8 alarm_en = i2c_smbus_read_byte_data(client, MAX6650_REG_ALARM_EN); + struct device_attribute *devattr; + + /* + * Hide the alarms that have not been enabled by the firmware + */ + + devattr = container_of(a, struct device_attribute, attr); + if (devattr == &sensor_dev_attr_fan1_max_alarm.dev_attr + || devattr == &sensor_dev_attr_fan1_min_alarm.dev_attr + || devattr == &sensor_dev_attr_fan1_fault.dev_attr + || devattr == &sensor_dev_attr_gpio1_alarm.dev_attr + || devattr == &sensor_dev_attr_gpio2_alarm.dev_attr) { + if (!(alarm_en & to_sensor_dev_attr(devattr)->index)) + return 0; + } + + return a->mode; +} + +static struct attribute *max6650_attrs[] = { + &sensor_dev_attr_fan1_input.dev_attr.attr, + &dev_attr_fan1_target.attr, + &dev_attr_fan1_div.attr, + &dev_attr_pwm1_enable.attr, + &dev_attr_pwm1.attr, + &sensor_dev_attr_fan1_max_alarm.dev_attr.attr, + &sensor_dev_attr_fan1_min_alarm.dev_attr.attr, + &sensor_dev_attr_fan1_fault.dev_attr.attr, + &sensor_dev_attr_gpio1_alarm.dev_attr.attr, + &sensor_dev_attr_gpio2_alarm.dev_attr.attr, + NULL +}; + +static const struct attribute_group max6650_group = { + .attrs = max6650_attrs, + .is_visible = max6650_attrs_visible, +}; + +static struct attribute *max6651_attrs[] = { + &sensor_dev_attr_fan2_input.dev_attr.attr, + &sensor_dev_attr_fan3_input.dev_attr.attr, + &sensor_dev_attr_fan4_input.dev_attr.attr, + NULL +}; + +static const struct attribute_group max6651_group = { + .attrs = max6651_attrs, +}; + +/* + * Real code + */ + +static int max6650_init_client(struct max6650_data *data, + struct i2c_client *client) +{ + struct device *dev = &client->dev; + int config; + int err = -EIO; + u32 voltage; + u32 prescale; + u32 target_rpm; + + if (of_property_read_u32(dev->of_node, "maxim,fan-microvolt", + &voltage)) + voltage = fan_voltage; + else + voltage /= 1000000; /* Microvolts to volts */ + if (of_property_read_u32(dev->of_node, "maxim,fan-prescale", + &prescale)) + prescale = prescaler; + + config = i2c_smbus_read_byte_data(client, MAX6650_REG_CONFIG); + + if (config < 0) { + dev_err(dev, "Error reading config, aborting.\n"); + return err; + } + + switch (voltage) { + case 0: + break; + case 5: + config &= ~MAX6650_CFG_V12; + break; + case 12: + config |= MAX6650_CFG_V12; + break; + default: + dev_err(dev, "illegal value for fan_voltage (%d)\n", voltage); + } + + switch (prescale) { + 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(dev, "illegal value for prescaler (%d)\n", prescale); + } + + dev_info(dev, "Fan voltage: %dV, prescaler: %d.\n", + (config & MAX6650_CFG_V12) ? 12 : 5, + 1 << (config & MAX6650_CFG_PRESCALER_MASK)); + + if (i2c_smbus_write_byte_data(client, MAX6650_REG_CONFIG, config)) { + dev_err(dev, "Config write error, aborting.\n"); + return err; + } + + data->config = config; + data->count = i2c_smbus_read_byte_data(client, MAX6650_REG_COUNT); + + if (!of_property_read_u32(client->dev.of_node, "maxim,fan-target-rpm", + &target_rpm)) { + max6650_set_target(data, target_rpm); + max6650_set_operating_mode(data, MAX6650_CFG_MODE_CLOSED_LOOP); + } + + return 0; +} + +static int max6650_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct device *dev = &client->dev; + const struct of_device_id *of_id = + of_match_device(of_match_ptr(max6650_dt_match), dev); + struct max6650_data *data; + struct device *hwmon_dev; + int err; + + data = devm_kzalloc(dev, sizeof(struct max6650_data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + data->client = client; + mutex_init(&data->update_lock); + data->nr_fans = of_id ? (int)(uintptr_t)of_id->data : id->driver_data; + + /* + * Initialize the max6650 chip + */ + err = max6650_init_client(data, client); + if (err) + return err; + + data->groups[0] = &max6650_group; + /* 3 additional fan inputs for the MAX6651 */ + if (data->nr_fans == 4) + data->groups[1] = &max6651_group; + + hwmon_dev = devm_hwmon_device_register_with_groups(dev, + client->name, data, + data->groups); + return PTR_ERR_OR_ZERO(hwmon_dev); +} + +static const struct i2c_device_id max6650_id[] = { + { "max6650", 1 }, + { "max6651", 4 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, max6650_id); + +static struct i2c_driver max6650_driver = { + .driver = { + .name = "max6650", + .of_match_table = of_match_ptr(max6650_dt_match), + }, + .probe = max6650_probe, + .id_table = max6650_id, +}; + +module_i2c_driver(max6650_driver); + +MODULE_AUTHOR("Hans J. Koch"); +MODULE_DESCRIPTION("MAX6650 sensor driver"); +MODULE_LICENSE("GPL"); |