This controller can be found on the D-Link DNS-323 for instance, where it is to be configured via static i2c_board_info in the board-specific mach-orion/dns323-setup.c (therefore I'm also providing new-style driver model compatibility) As this is my first attempt at writing a hwmon driver... please be patience with me if I didn't get it right :-) Signed-off-by: Herbert Valerio Riedel <hvr at gnu.org> --- Documentation/hwmon/g760a | 38 +++++ drivers/hwmon/Kconfig | 10 ++ drivers/hwmon/Makefile | 1 + drivers/hwmon/g760a.c | 378 +++++++++++++++++++++++++++++++++++++++++++++ include/linux/i2c-id.h | 1 + 5 files changed, 428 insertions(+), 0 deletions(-) create mode 100644 Documentation/hwmon/g760a create mode 100644 drivers/hwmon/g760a.c diff --git a/Documentation/hwmon/g760a b/Documentation/hwmon/g760a new file mode 100644 index 0000000..1992ea2 --- /dev/null +++ b/Documentation/hwmon/g760a @@ -0,0 +1,38 @@ +Kernel driver g760a +=================== + +Supported chips: + * Global Mixed-mode Technology Inc. G760A + Prefix: 'g760a' + Addresses scanned: I2C 0x3e + Datasheet: Publicly available at the GMT website + http://www.gmt.com.tw/datasheet/g760a.pdf + +Author: Herbert Valerio Riedel <hvr at gnu.org> + +Description +----------- + +The GMT G760A Fan Speed PWM Controller is connected directly to a fan +and performs closed-loop control of the fan speed. + +The fan speed is programmed by setting the period via 'pwm1' of two +consecutive speed pulses. The period is defined in terms of clock +cycle counts of an assumed 32kHz clock source. + +Setting a period of 255 stops the fan; setting the period to 0 sets +fan to maximum speed. + +The measured fan rotation speed returned via 'fan1_input' is derived +from the measured speed pulse period by assuming again a 32kHz clock +source and a 2 pulse-per-revolution fan. + +The 'alarms' file provides access to the two alarm bits provided by +the G760A chip's status register: Bit 0 is set when the actual fan +speed differs more than 20% with respect to the programmed fan speed; +bit 1 is set when fan speed is below 1920 rpm. + +The g760a driver will not update its values more frequently than every +other second; reading them more often will do no harm, but will return +'old' values. + diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig index 700a165..f7a3843 100644 --- a/drivers/hwmon/Kconfig +++ b/drivers/hwmon/Kconfig @@ -281,6 +281,16 @@ config SENSORS_FSCHMD This driver can also be built as a module. If so, the module will be called fschmd. +config SENSORS_G760A + tristate "GMT G760A" + depends on I2C + help + If you say yes here you get support for Global Mixed-mode + Technology Inc G760A fan speed pwm controller chips. + + This driver can also be built as a module. If so, the module + will be called g760a. + config SENSORS_GL518SM tristate "Genesys Logic GL518SM" depends on I2C diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile index 6da3eef..89657af 100644 --- a/drivers/hwmon/Makefile +++ b/drivers/hwmon/Makefile @@ -35,6 +35,7 @@ obj-$(CONFIG_SENSORS_F75375S) += f75375s.o obj-$(CONFIG_SENSORS_FSCHER) += fscher.o obj-$(CONFIG_SENSORS_FSCHMD) += fschmd.o obj-$(CONFIG_SENSORS_FSCPOS) += fscpos.o +obj-$(CONFIG_SENSORS_G760A) += g760a.o obj-$(CONFIG_SENSORS_GL518SM) += gl518sm.o obj-$(CONFIG_SENSORS_GL520SM) += gl520sm.o obj-$(CONFIG_SENSORS_HDAPS) += hdaps.o diff --git a/drivers/hwmon/g760a.c b/drivers/hwmon/g760a.c new file mode 100644 index 0000000..972d796 --- /dev/null +++ b/drivers/hwmon/g760a.c @@ -0,0 +1,378 @@ +/* + g760a - Driver for the Global Mixed-mode Technology Inc. G760A + fan speed PWM controller chip + + Copyright (C) 2007 Herbert Valerio Riedel <hvr at gnu.org> + + Complete datasheet is available at GMT's website: + http://www.gmt.com.tw/datasheet/g760a.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. +*/ + +#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/mutex.h> +#include <linux/sysfs.h> + +/* Addresses to scan */ +static unsigned short normal_i2c[] = { 0x3e, I2C_CLIENT_END }; + +/* Insmod parameters */ +I2C_CLIENT_INSMOD_1(g760a); + +enum g760a_regs { + G760A_REG_SET_CNT = 0x00, + G760A_REG_ACT_CNT = 0x01, + G760A_REG_FAN_STA = 0x02 +}; + +#define G760A_REG_FAN_STA_RPM_OFF 0x1 /* 20% off */ +#define G760A_REG_FAN_STA_RPM_LOW 0x2 /* below 1920rpm */ + +/* register data is read (and cached) at most once per second */ +#define G760A_UPDATE_INTERVAL (HZ) + +struct g760a_data { + struct i2c_client *client; + struct device *hwmon_dev; + struct mutex update_lock; + + /* board specific parameters */ + u32 clk; /* default 32kHz */ + u16 fan_div; /* default P=2 */ + + /* g760a register cache */ + int valid:1; + unsigned long last_updated; /* In jiffies */ + + u8 set_cnt; /* PWM (period) count number; 0xff stops fan */ + u8 act_cnt; /* formula: cnt = (CLK * 30)/(rpm * P) */ + u8 fan_sta; /* bit 0: set when actual fan speed more than %20 + * outside requested fan speed + * bit 1: set when fan speed below 1920 rpm */ +}; + +#define G760A_DEFAULT_CLK 32768 +#define G760A_DEFAULT_FAN_DIV 2 + +#define RPM_FROM_REG(val, clk, div) \ + ((0x00 == (val)) ? 0 : (((clk)*30)/((val)*(div)))) + +/* legacy driver model */ +static int g760a_attach_adapter(struct i2c_adapter *adapter); +static int g760a_detach_client(struct i2c_client *client); + +static struct i2c_driver g760a_legacy_driver = { + .driver = { + .name = "g760a_legacy", + }, + .id = I2C_DRIVERID_G760A, + .attach_adapter = g760a_attach_adapter, + .detach_client = g760a_detach_client, +}; + +/* new-style driver model */ +static int g760a_probe(struct i2c_client *client); +static int g760a_remove(struct i2c_client *client); + +static struct i2c_driver g760a_driver = { + .driver = { + .name = "g760a", + }, + .probe = g760a_probe, + .remove = g760a_remove, +}; + +/* read/write wrappers */ +static int g760a_read_value(struct i2c_client *client, enum g760a_regs reg) +{ + return i2c_smbus_read_byte_data(client, reg); +} + +static int g760a_write_value(struct i2c_client *client, enum g760a_regs reg, + u16 value) +{ + return i2c_smbus_write_byte_data(client, reg, value); +} + +/**************************************************************************** + * sysfs attributes + */ + +static struct g760a_data *g760a_update_client(struct device *dev) +{ + struct i2c_client *client = to_i2c_client(dev); + struct g760a_data *data = i2c_get_clientdata(client); + + mutex_lock(&data->update_lock); + + if (time_after(jiffies, data->last_updated + G760A_UPDATE_INTERVAL) + || !data->valid) { + dev_dbg(&client->dev, "Starting g760a update\n"); + + data->set_cnt = g760a_read_value(client, G760A_REG_SET_CNT); + data->act_cnt = g760a_read_value(client, G760A_REG_ACT_CNT); + data->fan_sta = g760a_read_value(client, G760A_REG_FAN_STA); + + data->last_updated = jiffies; + data->valid = 1; + } + + mutex_unlock(&data->update_lock); + + return data; +} + +static ssize_t show_fan(struct device *dev, struct device_attribute *da, + char *buf) +{ + struct g760a_data *data = g760a_update_client(dev); + int rpm = 0; + + mutex_lock(&data->update_lock); + if (!(data->fan_sta & G760A_REG_FAN_STA_RPM_LOW)) + rpm = RPM_FROM_REG(data->act_cnt, data->clk, data->fan_div); + mutex_unlock(&data->update_lock); + + return sprintf(buf, "%d\n", rpm); +} + +static ssize_t show_alarms(struct device *dev, struct device_attribute *da, + char *buf) +{ + struct g760a_data *data = g760a_update_client(dev); + + return sprintf(buf, "%d\n", data->fan_sta & 0x3); +} + +static ssize_t get_pwm(struct device *dev, struct device_attribute *da, + char *buf) +{ + struct g760a_data *data = g760a_update_client(dev); + + return sprintf(buf, "%d\n", data->set_cnt); +} + +static ssize_t set_pwm(struct device *dev, struct device_attribute *da, + const char *buf, size_t count) +{ + struct i2c_client *client = to_i2c_client(dev); + struct g760a_data *data = g760a_update_client(dev); + + const long val = simple_strtol(buf, NULL, 10); + + mutex_lock(&data->update_lock); + data->set_cnt = SENSORS_LIMIT(val, 0, 255); + g760a_write_value(client, G760A_REG_SET_CNT, data->set_cnt); + mutex_unlock(&data->update_lock); + + return count; +} + +static DEVICE_ATTR(pwm1, S_IWUSR | S_IRUGO, get_pwm, set_pwm); +static DEVICE_ATTR(fan1_input, S_IRUGO, show_fan, NULL); +static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL); + +static struct attribute *g760a_attributes[] = { + &dev_attr_pwm1.attr, + &dev_attr_fan1_input.attr, + &dev_attr_alarms.attr, + NULL +}; + +static const struct attribute_group g760a_group = { + .attrs = g760a_attributes, +}; + +/**************************************************************************** + * new-style driver model code + */ + +static int g760a_probe(struct i2c_client *client) +{ + struct g760a_data *data; + int err; + + if (!i2c_check_functionality(client->adapter, + I2C_FUNC_SMBUS_BYTE_DATA)) + return -EIO; + + data = kzalloc(sizeof(struct g760a_data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + i2c_set_clientdata(client, data); + + data->client = client; + mutex_init(&data->update_lock); + + /* setup default configuration for now */ + data->fan_div = G760A_DEFAULT_FAN_DIV; + data->clk = G760A_DEFAULT_CLK; + + /* Register sysfs hooks */ + err = sysfs_create_group(&client->dev.kobj, &g760a_group); + if (err) + goto error_sysfs_create_group; + + data->hwmon_dev = hwmon_device_register(&client->dev); + if (IS_ERR(data->hwmon_dev)) { + err = PTR_ERR(data->hwmon_dev); + goto error_hwmon_device_register; + } + + return 0; + +error_hwmon_device_register: + sysfs_remove_group(&client->dev.kobj, &g760a_group); +error_sysfs_create_group: + kfree(data); + i2c_set_clientdata(client, NULL); + + return err; +} + +static int g760a_remove(struct i2c_client *client) +{ + struct g760a_data *data = i2c_get_clientdata(client); + + hwmon_device_unregister(data->hwmon_dev); + sysfs_remove_group(&client->dev.kobj, &g760a_group); + kfree(data); + i2c_set_clientdata(client, NULL); + + return 0; +} + + +/**************************************************************************** + * legacy driver model code + */ + +static int g760a_detect(struct i2c_adapter *adapter, int address, int kind); + +static int g760a_attach_adapter(struct i2c_adapter *adapter) +{ + if (!(adapter->class & I2C_CLASS_HWMON)) + return 0; + return i2c_probe(adapter, &addr_data, g760a_detect); +} + +static int g760a_detect(struct i2c_adapter *adapter, int address, int kind) +{ + struct i2c_client *client; + int err = 0, i, set_cnt; + + if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) + goto exit; + + client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL); + if (!client) { + err = -ENOMEM; + goto exit; + } + + client->addr = address; + client->adapter = adapter; + client->driver = &g760a_legacy_driver; + + /* use heuristics to detect chip */ + set_cnt = i2c_smbus_read_byte_data(client, 0); + for (i = 0; i < 0x100; i += 4) { + /* verify that register 0 is mirrored every 4th position */ + if (i2c_smbus_read_byte_data(client, i) != set_cnt) + goto exit_free; + + /* test for unused bits */ + if (i2c_smbus_read_byte_data(client, i+2) & 0xfc) + goto exit_free; + + /* test for 0xff pattern */ + if (i2c_smbus_read_byte_data(client, i+3) != 0xff) + goto exit_free; + } + + /* Fill in client name */ + strlcpy(client->name, "g760a", I2C_NAME_SIZE); + + /* Tell the I2C layer a new client has arrived */ + err = i2c_attach_client(client); + if (err) + goto exit_free; + + /* delegate remaining setup to new-style code */ + err = g760a_probe(client); + if (err < 0) + goto exit_detach; + + return 0; + +exit_detach: + i2c_detach_client(client); +exit_free: + kfree(client); +exit: + return err; +} + +static int g760a_detach_client(struct i2c_client *client) +{ + struct g760a_data *data = i2c_get_clientdata(client); + int err; + + hwmon_device_unregister(data->hwmon_dev); + sysfs_remove_group(&client->dev.kobj, &g760a_group); + + err = i2c_detach_client(client); + if (err) + return err; + + kfree(data); + + return 0; +} + +/* module management */ + +static int __init g760a_init(void) +{ + int rc; + + rc = i2c_add_driver(&g760a_driver); + if (rc < 0) + goto error_add; + + rc = i2c_add_driver(&g760a_legacy_driver); + if (rc < 0) + goto error_add_legacy; + + return 0; + +error_add_legacy: + i2c_del_driver(&g760a_driver); +error_add: + return rc; +} + +static void __exit g760a_exit(void) +{ + i2c_del_driver(&g760a_driver); + i2c_del_driver(&g760a_legacy_driver); +} + +MODULE_AUTHOR("Herbert Valerio Riedel <hvr at gnu.org>"); +MODULE_DESCRIPTION("GMT G760A driver"); +MODULE_LICENSE("GPL"); + +module_init(g760a_init); +module_exit(g760a_exit); diff --git a/include/linux/i2c-id.h b/include/linux/i2c-id.h index 88c8140..47b8a11 100644 --- a/include/linux/i2c-id.h +++ b/include/linux/i2c-id.h @@ -163,6 +163,7 @@ #define I2C_DRIVERID_FSCHER 1046 #define I2C_DRIVERID_W83L785TS 1047 #define I2C_DRIVERID_OV7670 1048 /* Omnivision 7670 camera */ +#define I2C_DRIVERID_G760A 1049 /* * ---- Adapter types ---------------------------------------------------- -- 1.5.3.4
