Re: [PATCH] i2c driver fixes for 2.6.4

Greg KH
2004-03-16T00:09:00Z

ChangeSet 1.1608.74.17, 2004/03/15 13:09:45-08:00, aurelien@aurel32.net

[PATCH] I2C: New chip driver: ds1621

The following patch against kernel 2.6.4-mm1 adds the ds1621 driver (an
I2C sensor). I have ported it from the 2.4 version.

It has been reviewed by Jean Delvare, partly on IRC, and it is
"compliant" with Mark Hoffman's refactoring.

drivers/i2c/chips/Kconfig | 11 +
drivers/i2c/chips/Makefile | 1
drivers/i2c/chips/ds1621.c | 345 +++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 357 insertions(+)

diff -Nru a/drivers/i2c/chips/Kconfig b/drivers/i2c/chips/Kconfig
--- a/drivers/i2c/chips/Kconfig Mon Mar 15 14:33:54 2004
+++ b/drivers/i2c/chips/Kconfig Mon Mar 15 14:33:54 2004
@@ -33,6 +33,17 @@
This driver can also be built as a module. If so, the module
will be called asb100.

+config SENSORS_DS1621
+ tristate "Dallas Semiconductor DS1621 and DS1625"
+ depends on I2C && EXPERIMENTAL
+ select I2C_SENSOR
+ help
+ If you say yes here you get support for Dallas Semiconductor
+ DS1621 and DS1625 sensor chips.
+
+ This driver can also be built as a module. If so, the module
+ will be called ds1621.
+
config SENSORS_FSCHER
tristate "FSC Hermes"
depends on I2C && EXPERIMENTAL
diff -Nru a/drivers/i2c/chips/Makefile b/drivers/i2c/chips/Makefile
--- a/drivers/i2c/chips/Makefile Mon Mar 15 14:33:54 2004
+++ b/drivers/i2c/chips/Makefile Mon Mar 15 14:33:54 2004
@@ -8,6 +8,7 @@
obj-$(CONFIG_SENSORS_W83781D) += w83781d.o

obj-$(CONFIG_SENSORS_ADM1021) += adm1021.o
+obj-$(CONFIG_SENSORS_DS1621) += ds1621.o
obj-$(CONFIG_SENSORS_EEPROM) += eeprom.o
obj-$(CONFIG_SENSORS_FSCHER) += fscher.o
obj-$(CONFIG_SENSORS_GL518SM) += gl518sm.o
diff -Nru a/drivers/i2c/chips/ds1621.c b/drivers/i2c/chips/ds1621.c
--- /dev/null Wed Dec 31 16:00:00 1969
+++ b/drivers/i2c/chips/ds1621.c Mon Mar 15 14:33:54 2004
@@ -0,0 +1,345 @@
+/*
+ ds1621.c - Part of lm_sensors, Linux kernel modules for hardware
+ monitoring
+ Christian W. Zuckschwerdt <zany@triq.net> 2000-11-23
+ based on lm75.c by Frodo Looijaard <frodol@dds.nl>
+ Ported to Linux 2.6 by Aurelien Jarno <aurelien@aurel32.net> with
+ the help of Jean Delvare <khali@linux-fr.org>
+
+ 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/i2c.h>
+#include <linux/i2c-sensor.h>
+#include "lm75.h"
+
+/* Addresses to scan */
+static unsigned short normal_i2c[] = { I2C_CLIENT_END };
+static unsigned short normal_i2c_range[] = { 0x48, 0x4f, I2C_CLIENT_END };
+static unsigned int normal_isa[] = { I2C_CLIENT_ISA_END };
+static unsigned int normal_isa_range[] = { I2C_CLIENT_ISA_END };
+
+/* Insmod parameters */
+SENSORS_INSMOD_1(ds1621);
+static int polarity = -1;
+MODULE_PARM(polarity, "i");
+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 | 1 | 0 |POL |1SHOT| */
+#define DS1621_REG_CONFIG_MASK 0x0C
+#define DS1621_REG_CONFIG_VAL 0x08
+#define DS1621_REG_CONFIG_POLARITY 0x02
+#define DS1621_REG_CONFIG_1SHOT 0x01
+#define DS1621_REG_CONFIG_DONE 0x80
+
+/* The DS1621 registers */
+#define DS1621_REG_TEMP 0xAA /* word, RO */
+#define DS1621_REG_TEMP_MIN 0xA1 /* word, RW */
+#define DS1621_REG_TEMP_MAX 0xA2 /* word, RW */
+#define DS1621_REG_CONF 0xAC /* byte, RW */
+#define DS1621_COM_START 0xEE /* no data */
+
+/* The DS1621 configuration register */
+#define DS1621_ALARM_TEMP_HIGH 0x40
+#define DS1621_ALARM_TEMP_LOW 0x20
+
+/* Conversions. Rounding and limit checking is only done on the TO_REG
+ variants. Note that you should be a bit careful with which arguments
+ these macros are called: arguments may be evaluated more than once.
+ Fixing this is just not worth it. */
+#define ALARMS_FROM_REG(val) ((val) & \
+ (DS1621_ALARM_TEMP_HIGH | DS1621_ALARM_TEMP_LOW))
+
+/* Each client has this additional data */
+struct ds1621_data {
+ struct semaphore update_lock;
+ char valid; /* !=0 if following fields are valid */
+ unsigned long last_updated; /* In jiffies */
+
+ u16 temp, temp_min, temp_max; /* Register values, word */
+ u8 conf; /* Register encoding, combined */
+};
+
+static int ds1621_attach_adapter(struct i2c_adapter *adapter);
+static int ds1621_detect(struct i2c_adapter *adapter, int address,
+ int kind);
+static void ds1621_init_client(struct i2c_client *client);
+static int ds1621_detach_client(struct i2c_client *client);
+static struct ds1621_data *ds1621_update_client(struct device *dev);
+
+/* This is the driver that will be inserted */
+static struct i2c_driver ds1621_driver = {
+ .owner = THIS_MODULE,
+ .name = "ds1621",
+ .id = I2C_DRIVERID_DS1621,
+ .flags = I2C_DF_NOTIFY,
+ .attach_adapter = ds1621_attach_adapter,
+ .detach_client = ds1621_detach_client,
+};
+
+static int ds1621_id = 0;
+
+static u16 swap_bytes(u16 val)
+{
+ return (val >> 8) | (val << 8);
+}
+
+/* All registers are word-sized, except for the configuration register.
+ DS1621 uses a high-byte first convention, which is exactly opposite to
+ the usual practice. */
+static int ds1621_read_value(struct i2c_client *client, u8 reg)
+{
+ if (reg == DS1621_REG_CONF)
+ return i2c_smbus_read_byte_data(client, reg);
+ else
+ return swap_bytes(i2c_smbus_read_word_data(client, reg));
+}
+
+/* All registers are word-sized, except for the configuration register.
+ DS1621 uses a high-byte first convention, which is exactly opposite to
+ the usual practice. */
+static int ds1621_write_value(struct i2c_client *client, u8 reg, u16 value)
+{
+ if (reg == DS1621_REG_CONF)
+ return i2c_smbus_write_byte_data(client, reg, value);
+ else
+ return i2c_smbus_write_word_data(client, reg,
+ swap_bytes(value));
+}
+
+static void ds1621_init_client(struct i2c_client *client)
+{
+ int reg = ds1621_read_value(client, DS1621_REG_CONF);
+ /* switch to continous conversion mode */
+ reg &= ~ DS1621_REG_CONFIG_1SHOT;
+
+ /* setup output polarity */
+ if (polarity == 0)
+ reg &= ~DS1621_REG_CONFIG_POLARITY;
+ else if (polarity == 1)
+ reg |= DS1621_REG_CONFIG_POLARITY;
+
+ ds1621_write_value(client, DS1621_REG_CONF, reg);
+
+ /* start conversion */
+ i2c_smbus_write_byte(client, DS1621_COM_START);
+}
+
+#define show(value) \
+static ssize_t show_##value(struct device *dev, char *buf) \
+{ \
+ struct ds1621_data *data = ds1621_update_client(dev); \
+ return sprintf(buf, "%d\n", LM75_TEMP_FROM_REG(data->value)); \
+}
+
+show(temp);
+show(temp_min);
+show(temp_max);
+
+#define set_temp(suffix, value, reg) \
+static ssize_t set_temp_##suffix(struct device *dev, const char *buf, \
+ size_t count) \
+{ \
+ struct i2c_client *client = to_i2c_client(dev); \
+ struct ds1621_data *data = ds1621_update_client(dev); \
+ data->value = LM75_TEMP_TO_REG(simple_strtoul(buf, NULL, 10)); \
+ ds1621_write_value(client, reg, data->value); \
+ return count; \
+}
+
+set_temp(min, temp_min, DS1621_REG_TEMP_MIN);
+set_temp(max, temp_max, DS1621_REG_TEMP_MAX);
+
+static ssize_t show_alarms(struct device *dev, char *buf)
+{
+ struct ds1621_data *data = ds1621_update_client(dev);
+ return sprintf(buf, "%d\n", ALARMS_FROM_REG(data->conf));
+}
+
+static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
+static DEVICE_ATTR(temp1_input, S_IRUGO , show_temp, NULL);
+static DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO , show_temp_min, set_temp_min);
+static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp_max, set_temp_max);
+
+
+static int ds1621_attach_adapter(struct i2c_adapter *adapter)
+{
+ return i2c_detect(adapter, &addr_data, ds1621_detect);
+}
+
+/* This function is called by i2c_detect */
+int ds1621_detect(struct i2c_adapter *adapter, int address,
+ int kind)
+{
+ int conf, temp;
+ struct i2c_client *new_client;
+ struct ds1621_data *data;
+ int err = 0;
+
+ if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
+ | I2C_FUNC_SMBUS_WORD_DATA
+ | I2C_FUNC_SMBUS_WRITE_BYTE))
+ goto exit;
+
+ /* OK. For now, we presume we have a valid client. We now create the
+ client structure, even though we cannot fill it completely yet.
+ But it allows us to access ds1621_{read,write}_value. */
+ if (!(new_client = kmalloc(sizeof(struct i2c_client) +
+ sizeof(struct ds1621_data),
+ GFP_KERNEL))) {
+ err = -ENOMEM;
+ goto exit;
+ }
+ memset(new_client, 0, sizeof(struct i2c_client) +
+ sizeof(struct ds1621_data));
+
+ data = (struct ds1621_data *) (new_client + 1);
+ i2c_set_clientdata(new_client, data);
+ new_client->addr = address;
+ new_client->adapter = adapter;
+ new_client->driver = &ds1621_driver;
+ new_client->flags = 0;
+
+
+ /* Now, we do the remaining detection. It is lousy. */
+ if (kind < 0) {
+ conf = ds1621_read_value(new_client, DS1621_REG_CONF);
+ if ((conf & DS1621_REG_CONFIG_MASK) != DS1621_REG_CONFIG_VAL)
+ goto exit_free;
+ temp = ds1621_read_value(new_client, DS1621_REG_TEMP);
+ if (temp & 0x007f)
+ goto exit_free;
+ temp = ds1621_read_value(new_client, DS1621_REG_TEMP_MIN);
+ if (temp & 0x007f)
+ goto exit_free;
+ temp = ds1621_read_value(new_client, DS1621_REG_TEMP_MAX);
+ if (temp & 0x007f)
+ goto exit_free;
+ }
+
+ /* Determine the chip type - only one kind supported! */
+ if (kind <= 0)
+ kind = ds1621;
+
+ /* Fill in remaining client fields and put it into the global list */
+ strlcpy(new_client->name, "ds1621", I2C_NAME_SIZE);
+
+ new_client->id = ds1621_id++;
+ data->valid = 0;
+ init_MUTEX(&data->update_lock);
+
+ /* Tell the I2C layer a new client has arrived */
+ if ((err = i2c_attach_client(new_client)))
+ goto exit_free;
+
+ /* Initialize the DS1621 chip */
+ ds1621_init_client(new_client);
+
+ /* Register sysfs hooks */
+ device_create_file(&new_client->dev, &dev_attr_alarms);
+ device_create_file(&new_client->dev, &dev_attr_temp1_input);
+ device_create_file(&new_client->dev, &dev_attr_temp1_min);
+ device_create_file(&new_client->dev, &dev_attr_temp1_max);
+
+ return 0;
+
+/* OK, this is not exactly good programming practice, usually. But it is
+ very code-efficient in this case. */
+ exit_free:
+ kfree(new_client);
+ exit:
+ return err;
+}
+
+static int ds1621_detach_client(struct i2c_client *client)
+{
+ int err;
+
+ if ((err = i2c_detach_client(client))) {
+ dev_err(&client->dev,
+ "ds1621.o: Client deregistration failed, client not detached.\n");
+ return err;
+ }
+
+ kfree(client);
+
+ return 0;
+}
+
+
+static struct ds1621_data *ds1621_update_client(struct device *dev)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct ds1621_data *data = i2c_get_clientdata(client);
+ u8 new_conf;
+
+ down(&data->update_lock);
+
+ if ((jiffies - data->last_updated > HZ + HZ / 2) ||
+ (jiffies < data->last_updated) || !data->valid) {
+
+ dev_dbg(&client->dev, "Starting ds1621 update\n");
+
+ data->conf = ds1621_read_value(client, DS1621_REG_CONF);
+
+ data->temp = ds1621_read_value(client, DS1621_REG_TEMP);
+
+ data->temp_min = ds1621_read_value(client,
+ DS1621_REG_TEMP_MIN);
+ data->temp_max = ds1621_read_value(client,
+ DS1621_REG_TEMP_MAX);
+
+ /* reset alarms if neccessary */
+ new_conf = data->conf;
+ if (data->temp < data->temp_min)
+ new_conf &= ~DS1621_ALARM_TEMP_LOW;
+ if (data->temp > data->temp_max)
+ new_conf &= ~DS1621_ALARM_TEMP_HIGH;
+ if (data->conf != new_conf)
+ ds1621_write_value(client, DS1621_REG_CONF,
+ new_conf);
+
+ data->last_updated = jiffies;
+ data->valid = 1;
+ }
+
+ up(&data->update_lock);
+
+ return data;
+}
+
+static int __init ds1621_init(void)
+{
+ return i2c_add_driver(&ds1621_driver);
+}
+
+static void __exit ds1621_exit(void)
+{
+ i2c_del_driver(&ds1621_driver);
+}
+
+
+MODULE_AUTHOR("Christian W. Zuckschwerdt <zany@triq.net>");
+MODULE_DESCRIPTION("DS1621 driver");
+MODULE_LICENSE("GPL");
+
+module_init(ds1621_init);
+module_exit(ds1621_exit);