From cd6c8a4297ad036a155966db49982d6807e23ef8 Mon Sep 17 00:00:00 2001 From: Robert Coulson Date: Wed, 8 May 2013 22:45:53 -0700 Subject: hwmon: (ds1621) Add ds1721 chip support Update the ds1621 documentation, driver, and Kconfig with ds1721 chip support. Signed-off-by: Robert Coulson Signed-off-by: Guenter Roeck --- drivers/hwmon/ds1621.c | 120 +++++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 106 insertions(+), 14 deletions(-) (limited to 'drivers/hwmon/ds1621.c') diff --git a/drivers/hwmon/ds1621.c b/drivers/hwmon/ds1621.c index 1c568736baff..6942617666a4 100644 --- a/drivers/hwmon/ds1621.c +++ b/drivers/hwmon/ds1621.c @@ -6,6 +6,19 @@ * Ported to Linux 2.6 by Aurelien Jarno with * the help of Jean Delvare * + * The DS1621 device is a digital temperature/thermometer with 9-bit + * resolution, a thermal alarm output (Tout), and user-defined minimum + * and maximum temperature thresholds (TH and TL). + * + * The DS1625 and DS1721 are pin compatible with the DS1621 and similar + * in operation, with slight variations as noted in the device + * datasheets (please refer to www.maximintegrated.com for specific + * device information). + * + * Since the DS1621 was the first chipset supported by this driver, + * most comments will refer to this chipset, but are actually general + * and concern all supported chipsets, unless mentioned otherwise. + * * 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 @@ -31,27 +44,62 @@ #include #include #include -#include "lm75.h" +#include /* Addresses to scan */ static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, I2C_CLIENT_END }; +/* Supported devices */ +enum chips { ds1621, ds1625, ds1721 }; + /* Insmod parameters */ static int polarity = -1; module_param(polarity, int, 0); MODULE_PARM_DESC(polarity, "Output's polarity: 0 = active high, 1 = active low"); -/* Many DS1621 constants specified below */ -/* Config register used for detection */ -/* 7 6 5 4 3 2 1 0 */ -/* |Done|THF |TLF |NVB | X | X |POL |1SHOT| */ +/* + * The Configuration/Status register + * + * - DS1621: + * 7 6 5 4 3 2 1 0 + * |Done|THF |TLF |NVB | X | X |POL |1SHOT| + * + * - DS1625: + * 7 6 5 4 3 2 1 0 + * |Done|THF |TLF |NVB | 1 | 0 |POL |1SHOT| + * + * - DS1721: + * 7 6 5 4 3 2 1 0 + * |Done| X | X | U | R1 | R0 |POL |1SHOT| + * + * Where: + * - 'X' is Reserved + * - 'U' is Undefined + */ #define DS1621_REG_CONFIG_NVB 0x10 +#define DS1621_REG_CONFIG_RESOL 0x0C #define DS1621_REG_CONFIG_POLARITY 0x02 #define DS1621_REG_CONFIG_1SHOT 0x01 #define DS1621_REG_CONFIG_DONE 0x80 -/* The DS1621 registers */ +#define DS1621_REG_CONFIG_RESOL_SHIFT 2 + +/* ds1721 conversion rates: {C/LSB, time(ms), resolution bit setting} */ +static const unsigned short ds1721_convrates[] = { + 94, /* 9-bits (0.5, 93.75, RES[0..1] = 0 */ + 188, /* 10-bits (0.25, 187.5, RES[0..1] = 1 */ + 375, /* 11-bits (0.125, 375, RES[0..1] = 2 */ + 750, /* 12-bits (0.0625, 750, RES[0..1] = 3 */ +}; + +#define DS1621_CONVERSION_MAX 750 +#define DS1625_CONVERSION_MAX 500 + +#define DS1621_TEMP_MAX 125000 +#define DS1621_TEMP_MIN (-55000) + +/* The DS1621 temperature registers */ static const u8 DS1621_REG_TEMP[3] = { 0xAA, /* input, word, RO */ 0xA2, /* min, word, RW */ @@ -59,6 +107,7 @@ static const u8 DS1621_REG_TEMP[3] = { }; #define DS1621_REG_CONF 0xAC /* byte, RW */ #define DS1621_COM_START 0xEE /* no data */ +#define DS1721_COM_START 0x51 /* no data */ #define DS1621_COM_STOP 0x22 /* no data */ /* The DS1621 configuration register */ @@ -75,14 +124,37 @@ struct ds1621_data { struct mutex update_lock; char valid; /* !=0 if following fields are valid */ unsigned long last_updated; /* In jiffies */ + enum chips kind; /* device type */ u16 temp[3]; /* Register values, word */ u8 conf; /* Register encoding, combined */ + u16 update_interval; /* Conversion rate in milliseconds */ }; +static inline int DS1621_TEMP_FROM_REG(u16 reg) +{ + return DIV_ROUND_CLOSEST(((s16)reg / 16) * 625, 10); +} + +/* + * TEMP: 0.001C/bit (-55C to +125C) + * REG: + * - 1621, 1625: x = 0.5C + * - 1721: x = 0.0625C + * Assume highest resolution and let the bits fall where they may.. + */ +static inline u16 DS1621_TEMP_TO_REG(long temp) +{ + int ntemp = clamp_val(temp, DS1621_TEMP_MIN, DS1621_TEMP_MAX); + ntemp += (ntemp < 0 ? -31 : 31); + ntemp = DIV_ROUND_CLOSEST(ntemp * 10, 625) << 4; + return (u16)ntemp; +} + static void ds1621_init_client(struct i2c_client *client) { - u8 conf, new_conf; + u8 conf, new_conf, sreg, resol; + struct ds1621_data *data = i2c_get_clientdata(client); new_conf = conf = i2c_smbus_read_byte_data(client, DS1621_REG_CONF); /* switch to continuous conversion mode */ @@ -97,8 +169,25 @@ static void ds1621_init_client(struct i2c_client *client) if (conf != new_conf) i2c_smbus_write_byte_data(client, DS1621_REG_CONF, new_conf); + switch (data->kind) { + case ds1625: + data->update_interval = DS1625_CONVERSION_MAX; + sreg = DS1621_COM_START; + break; + case ds1721: + resol = (new_conf & DS1621_REG_CONFIG_RESOL) >> + DS1621_REG_CONFIG_RESOL_SHIFT; + data->update_interval = ds1721_convrates[resol]; + sreg = DS1721_COM_START; + break; + default: + data->update_interval = DS1621_CONVERSION_MAX; + sreg = DS1621_COM_START; + break; + } + /* start conversion */ - i2c_smbus_write_byte(client, DS1621_COM_START); + i2c_smbus_write_byte(client, sreg); } static struct ds1621_data *ds1621_update_client(struct device *dev) @@ -109,8 +198,8 @@ static struct ds1621_data *ds1621_update_client(struct device *dev) mutex_lock(&data->update_lock); - if (time_after(jiffies, data->last_updated + HZ + HZ / 2) - || !data->valid) { + if (time_after(jiffies, data->last_updated + data->update_interval) || + !data->valid) { int i; dev_dbg(&client->dev, "Starting ds1621 update\n"); @@ -146,7 +235,7 @@ static ssize_t show_temp(struct device *dev, struct device_attribute *da, struct sensor_device_attribute *attr = to_sensor_dev_attr(da); struct ds1621_data *data = ds1621_update_client(dev); return sprintf(buf, "%d\n", - LM75_TEMP_FROM_REG(data->temp[attr->index])); + DS1621_TEMP_FROM_REG(data->temp[attr->index])); } static ssize_t set_temp(struct device *dev, struct device_attribute *da, @@ -163,7 +252,7 @@ static ssize_t set_temp(struct device *dev, struct device_attribute *da, return err; mutex_lock(&data->update_lock); - data->temp[attr->index] = LM75_TEMP_TO_REG(val); + data->temp[attr->index] = DS1621_TEMP_TO_REG(val); i2c_smbus_write_word_swapped(client, DS1621_REG_TEMP[attr->index], data->temp[attr->index]); mutex_unlock(&data->update_lock); @@ -257,6 +346,8 @@ static int ds1621_probe(struct i2c_client *client, i2c_set_clientdata(client, data); mutex_init(&data->update_lock); + data->kind = id->driver_data; + /* Initialize the DS1621 chip */ ds1621_init_client(client); @@ -289,8 +380,9 @@ static int ds1621_remove(struct i2c_client *client) } static const struct i2c_device_id ds1621_id[] = { - { "ds1621", 0 }, - { "ds1625", 0 }, + { "ds1621", ds1621 }, + { "ds1625", ds1625 }, + { "ds1721", ds1721 }, { } }; MODULE_DEVICE_TABLE(i2c, ds1621_id); -- cgit v1.2.3-70-g09d2