Updates and cleanups for lm75:
- Update the LM75 driver to handle new-style I2C driver binding
(following the driver model).
- Use 12 bit resolution (1/16 degree C) on chips that support it,
instead of 9 bit (1/2 degree C); needs new conversion routines.
- Grow the list of compatible chips; update Kconfig accordingly.
- On driver disconnect, restore the original device config (which
usually means shutdown).
- Some code cleanups: a handful of whitespace fixes, and clearly
marking the various driver components (sysfs/hwmon attributes,
driver core support, legacy stuff, register access, module glue).
The way to kick in higher sample resolution on a given board is to
use the new style binding to pass in the chip type.
One temporary omission: IRQ support, or for the TI chips SMBALERT#
notifications.
Signed-off-by: David Brownell <dbrownell at users.sourceforge.net>
---
drivers/hwmon/Kconfig | 22 ++--
drivers/hwmon/lm75.c | 274 ++++++++++++++++++++++++++++++++++++--------------
2 files changed, 216 insertions(+), 80 deletions(-)
--- a/drivers/hwmon/Kconfig 2007-09-16 16:38:18.000000000 -0700
+++ b/drivers/hwmon/Kconfig 2007-09-16 16:38:18.000000000 -0700
@@ -301,13 +301,23 @@ config SENSORS_LM75
tristate "National Semiconductor LM75 and compatibles"
depends on I2C
help
- If you say yes here you get support for National Semiconductor LM75
- sensor chips and clones: Dallas Semiconductor DS75 and DS1775 (in
- 9-bit precision mode), and TelCom (now Microchip) TCN75.
+ If you say yes here you get support for one common type of
+ temperature sensor chip, with models including:
- The DS75 and DS1775 in 10- to 12-bit precision modes will require
- a force module parameter. The driver will not handle the extra
- precision anyhow.
+ - Dallas Semiconductor DS75 and DS1775
+ - Microchip MCP980x
+ - National Semiconductor LM75
+ - ST Microelectronics STDS75
+ - TelCom (now Microchip) TCN75
+ - Texas Instruments TMP75, TMP175, and TMP275
+
+ This driver supports driver model based binding through board
+ specific I2C device tables. When those tables report a chip
+ type that's recognized as supporting it, this driver uses 12-bit
+ sample resolution (to 1/16 degree C).
+
+ It also supports the "legacy" style of driver binding. To use
+ that with some chips, you may need the "force" module parameter.
This driver can also be built as a module. If so, the module
will be called lm75.
--- a/drivers/hwmon/lm75.c 2007-09-16 16:33:53.000000000 -0700
+++ b/drivers/hwmon/lm75.c 2007-09-16 16:38:18.000000000 -0700
@@ -27,17 +27,21 @@
#include <linux/hwmon-sysfs.h>
#include <linux/err.h>
#include <linux/mutex.h>
-#include "lm75.h"
-/* Addresses to scan */
+/*
+ * This driver handles (at least) the DS75, DS1775, LM75, MCP980x,
+ * STDS75, TCN75, TMP75, TMP175, TMP275, and other digital temperature
+ * sensors.
+ */
+
+/* Addresses scanned by legacy style driver binding */
static unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c,
0x4d, 0x4e, 0x4f, I2C_CLIENT_END };
-/* Insmod parameters */
+/* Insmod parameters (only for legacy style binding) */
I2C_CLIENT_INSMOD_1(lm75);
-/* Many LM75 constants specified below */
/* The LM75 registers */
#define LM75_REG_CONF 0x01
@@ -49,43 +53,79 @@ static const u8 LM75_REG_TEMP[3] = {
/* Each client has this additional data */
struct lm75_data {
- struct i2c_client client;
- struct class_device *class_dev;
+ struct i2c_client *client;
+ struct class_device *hwmon;
struct mutex update_lock;
- char valid; /* !=0 if following fields are valid */
+ int min, max;
+ char orig_conf;
+ char valid; /* !=0 if registers are valid */
unsigned long last_updated; /* In jiffies */
u16 temp[3]; /* Register values,
0 = input
1 = max
2 = hyst */
+ u16 round; /* f(resolution) */
};
static int lm75_attach_adapter(struct i2c_adapter *adapter);
-static int lm75_detect(struct i2c_adapter *adapter, int address, int kind);
-static void lm75_init_client(struct i2c_client *client);
static int lm75_detach_client(struct i2c_client *client);
static int lm75_read_value(struct i2c_client *client, u8 reg);
static int lm75_write_value(struct i2c_client *client, u8 reg, u16 value);
static struct lm75_data *lm75_update_device(struct device *dev);
-/* This is the driver that will be inserted */
-static struct i2c_driver lm75_driver = {
+/* We handle both I2C driver binding models */
+static struct i2c_driver lm75_legacy_driver = {
.driver = {
- .name = "lm75",
+ .name = "lm75_legacy",
},
.id = I2C_DRIVERID_LM75,
.attach_adapter = lm75_attach_adapter,
.detach_client = lm75_detach_client,
};
+static int lm75_probe(struct i2c_client *client);
+static int lm75_remove(struct i2c_client *client);
+
+static struct i2c_driver lm75_driver = {
+ .driver = {
+ .name = "lm75",
+ },
+ .probe = lm75_probe,
+ .remove = lm75_remove,
+};
+
+/*-----------------------------------------------------------------------*/
+
+/* sysfs attributes for hwmon, handling any sample resolution */
+
+static inline s16 temp_to_reg(struct lm75_data *lm75, long temp)
+{
+ if (temp < lm75->min)
+ temp = lm75->min;
+ else if (temp > lm75->max)
+ temp = lm75->max;
+
+ /* this "rounding" is squirrely but backwards-compatible */
+ temp += (temp < 0) ? -lm75->round : lm75->round;
+ return (temp * 256) / 1000;
+}
+
+static inline int reg_to_temp(s16 reg)
+{
+ /* Use integer division instead of logical right shift to
+ * preserve sign (compiler uses arithmetic right shift).
+ */
+ return (reg * 1000) / 256;
+}
+
static ssize_t show_temp(struct device *dev, struct device_attribute *da,
char *buf)
{
struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
struct lm75_data *data = lm75_update_device(dev);
- return sprintf(buf, "%d\n",
- LM75_TEMP_FROM_REG(data->temp[attr->index]));
+
+ return sprintf(buf, "%d\n", reg_to_temp(data->temp[attr->index]));
}
static ssize_t set_temp(struct device *dev, struct device_attribute *da,
@@ -98,7 +138,7 @@ static ssize_t set_temp(struct device *d
unsigned long temp = simple_strtoul(buf, NULL, 10);
mutex_lock(&data->update_lock);
- data->temp[nr] = LM75_TEMP_TO_REG(temp);
+ data->temp[nr] = temp_to_reg(data, temp);
lm75_write_value(client, LM75_REG_TEMP[nr], data->temp[nr]);
mutex_unlock(&data->update_lock);
return count;
@@ -110,13 +150,6 @@ static SENSOR_DEVICE_ATTR(temp1_max_hyst
show_temp, set_temp, 2);
static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
-static int lm75_attach_adapter(struct i2c_adapter *adapter)
-{
- if (!(adapter->class & I2C_CLASS_HWMON))
- return 0;
- return i2c_probe(adapter, &addr_data, lm75_detect);
-}
-
static struct attribute *lm75_attributes[] = {
&sensor_dev_attr_temp1_input.dev_attr.attr,
&sensor_dev_attr_temp1_max.dev_attr.attr,
@@ -129,32 +162,134 @@ static const struct attribute_group lm75
.attrs = lm75_attributes,
};
+/*-----------------------------------------------------------------------*/
+
+/* "New style" I2C driver binding -- following the driver model */
+
+static int lm75_probe(struct i2c_client *client)
+{
+ struct lm75_data *data;
+ int status;
+ u8 set_mask, clr_mask;
+ int new;
+ int resolution;
+
+ if (!i2c_check_functionality(client->adapter,
+ I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA))
+ return -EIO;
+
+ if (!(data = kzalloc(sizeof(struct lm75_data), GFP_KERNEL)))
+ return -ENOMEM;
+
+ i2c_set_clientdata(client, data);
+
+ data->client = client;
+ mutex_init(&data->update_lock);
+
+ /* Set to LM75 resolution (9 bits, 0.5 degrees C) and range.
+ * Then tweak to be more precise when appropriate.
+ */
+ set_mask = 0;
+ clr_mask = (1 << 0) /* continuous conversions */
+ | (1 << 6) | (1 << 5); /* 9-bit mode */
+ resolution = 9;
+
+ /* for ds1175, use name "ds75".
+ * for tmp175 or tmp275, use name "tmp75".
+ */
+ if (strcmp(client->name, "ds75") == 0
+ || strcmp(client->name, "mcp980x") == 0
+ || strcmp(client->name, "tmp75") == 0) {
+ resolution = 12;
+ set_mask |= (1 << 6) | (1 << 5);
+ }
+ data->round = 500 / (1 << (resolution - 8));
+
+ data->min = -55 * 1000;
+ data->max = 125 * 1000;
+
+ if (strcmp(client->name, "tmp75") == 0)
+ data->min = -40 * 1000;
+
+ /* NOTE: also need to ensure that the chip is in interrupt mode
+ * in various cases, and maybe handle SMBALERT#.
+ */
+
+ /* configure as specified */
+ status = lm75_read_value(client, LM75_REG_CONF);
+ if (status < 0) {
+ dev_dbg(&client->dev, "can't read config? %d\n", status);
+ goto exit_free;
+ }
+ data->orig_conf = status;
+ new = status & ~clr_mask;
+ new |= set_mask;
+ if (status != new)
+ lm75_write_value(client, LM75_REG_CONF, new);
+ dev_dbg(&client->dev, "config %02x\n", new);
+
+ /* Register sysfs hooks */
+ if ((status = sysfs_create_group(&client->dev.kobj, &lm75_group)))
+ goto exit_free;
+
+ data->hwmon = hwmon_device_register(&client->dev);
+ if (IS_ERR(data->hwmon)) {
+ status = PTR_ERR(data->hwmon);
+ goto exit_remove;
+ }
+
+ dev_info(&client->dev,
+ "%s: sensor '%s', resolution 0.%03d degrees C\n",
+ data->hwmon->class_id, client->name, data->round * 2);
+
+ return 0;
+
+exit_remove:
+ sysfs_remove_group(&client->dev.kobj, &lm75_group);
+exit_free:
+ kfree(data);
+ i2c_set_clientdata(client, NULL);
+ return status;
+}
+
+static int lm75_remove(struct i2c_client *client)
+{
+ struct lm75_data *data = i2c_get_clientdata(client);
+
+ hwmon_device_unregister(data->hwmon);
+ sysfs_remove_group(&client->dev.kobj, &lm75_group);
+ lm75_write_value(client, LM75_REG_CONF, data->orig_conf);
+ kfree(data);
+ i2c_set_clientdata(client, NULL);
+ return 0;
+}
+
+/*-----------------------------------------------------------------------*/
+
+/* "Legacy" I2C driver binding */
+
/* This function is called by i2c_probe */
static int lm75_detect(struct i2c_adapter *adapter, int address, int kind)
{
int i;
struct i2c_client *new_client;
- struct lm75_data *data;
int err = 0;
- const char *name = "";
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
I2C_FUNC_SMBUS_WORD_DATA))
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.
+ /* OK. For now, we presume we have a valid address. We create the
+ client structure, even though there may be no sensor present.
But it allows us to access lm75_{read,write}_value. */
- if (!(data = kzalloc(sizeof(struct lm75_data), GFP_KERNEL))) {
+ if (!(new_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL))) {
err = -ENOMEM;
goto exit;
}
- new_client = &data->client;
- i2c_set_clientdata(new_client, data);
new_client->addr = address;
new_client->adapter = adapter;
- new_client->driver = &lm75_driver;
+ new_client->driver = &lm75_legacy_driver;
new_client->flags = 0;
/* Now, we do the remaining detection. There is no identification-
@@ -175,17 +310,17 @@ static int lm75_detect(struct i2c_adapte
|| i2c_smbus_read_word_data(new_client, 5) != hyst
|| i2c_smbus_read_word_data(new_client, 6) != hyst
|| i2c_smbus_read_word_data(new_client, 7) != hyst)
- goto exit_free;
+ goto exit_free;
os = i2c_smbus_read_word_data(new_client, 3);
if (i2c_smbus_read_word_data(new_client, 4) != os
|| i2c_smbus_read_word_data(new_client, 5) != os
|| i2c_smbus_read_word_data(new_client, 6) != os
|| i2c_smbus_read_word_data(new_client, 7) != os)
- goto exit_free;
+ goto exit_free;
/* Unused bits */
if (conf & 0xe0)
- goto exit_free;
+ goto exit_free;
/* Addresses cycling */
for (i = 8; i < 0xff; i += 8)
@@ -193,60 +328,46 @@ static int lm75_detect(struct i2c_adapte
|| i2c_smbus_read_word_data(new_client, i + 2) != hyst
|| i2c_smbus_read_word_data(new_client, i + 3) != os)
goto exit_free;
- }
-
- /* Determine the chip type - only one kind supported! */
- if (kind <= 0)
- kind = lm75;
- if (kind == lm75) {
- name = "lm75";
+ strlcpy(new_client->name, "lm75", I2C_NAME_SIZE);
}
- /* Fill in the remaining client fields and put it into the global list */
- strlcpy(new_client->name, name, I2C_NAME_SIZE);
- data->valid = 0;
- mutex_init(&data->update_lock);
-
/* Tell the I2C layer a new client has arrived */
if ((err = i2c_attach_client(new_client)))
goto exit_free;
- /* Initialize the LM75 chip */
- lm75_init_client(new_client);
-
- /* Register sysfs hooks */
- if ((err = sysfs_create_group(&new_client->dev.kobj, &lm75_group)))
+ if ((err = lm75_probe(new_client)) < 0)
goto exit_detach;
- data->class_dev = hwmon_device_register(&new_client->dev);
- if (IS_ERR(data->class_dev)) {
- err = PTR_ERR(data->class_dev);
- goto exit_remove;
- }
-
return 0;
-exit_remove:
- sysfs_remove_group(&new_client->dev.kobj, &lm75_group);
exit_detach:
i2c_detach_client(new_client);
exit_free:
- kfree(data);
+ kfree(new_client);
exit:
return err;
}
+static int lm75_attach_adapter(struct i2c_adapter *adapter)
+{
+ if (!(adapter->class & I2C_CLASS_HWMON))
+ return 0;
+ return i2c_probe(adapter, &addr_data, lm75_detect);
+}
+
static int lm75_detach_client(struct i2c_client *client)
{
- struct lm75_data *data = i2c_get_clientdata(client);
- hwmon_device_unregister(data->class_dev);
- sysfs_remove_group(&client->dev.kobj, &lm75_group);
+ lm75_remove(client);
i2c_detach_client(client);
- kfree(data);
+ kfree(client);
return 0;
}
+/*-----------------------------------------------------------------------*/
+
+/* register access */
+
/* All registers are word-sized, except for the configuration register.
LM75 uses a high-byte first convention, which is exactly opposite to
the usual practice. */
@@ -269,16 +390,6 @@ static int lm75_write_value(struct i2c_c
return i2c_smbus_write_word_data(client, reg, swab16(value));
}
-static void lm75_init_client(struct i2c_client *client)
-{
- int reg;
-
- /* Enable if in shutdown mode */
- reg = lm75_read_value(client, LM75_REG_CONF);
- if (reg >= 0 && (reg & 0x01))
- lm75_write_value(client, LM75_REG_CONF, reg & 0xfe);
-}
-
static struct lm75_data *lm75_update_device(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
@@ -303,13 +414,28 @@ static struct lm75_data *lm75_update_dev
return data;
}
+/*-----------------------------------------------------------------------*/
+
+/* module glue */
+
static int __init sensors_lm75_init(void)
{
- return i2c_add_driver(&lm75_driver);
+ int status;
+
+ status = i2c_add_driver(&lm75_driver);
+ if (status < 0)
+ return status;
+
+ status = i2c_add_driver(&lm75_legacy_driver);
+ if (status < 0)
+ i2c_del_driver(&lm75_driver);
+
+ return status;
}
static void __exit sensors_lm75_exit(void)
{
+ i2c_del_driver(&lm75_legacy_driver);
i2c_del_driver(&lm75_driver);
}
