Teach the LM75 driver how to use new-style driver binding:
- Create a second driver struct, using new-style driver binding methods
cribbed from the legacy code.
- Make the legacy probe logic delegate all its work to this new code.
- The old driver struct was renamed as "lm75_legacy".
- Sensor limits are chip-specific; record them, and use them in new
routines to interconvert temperature and register values.
- More careful initialization. Chips are put into 9-bit mode so
that extra precision can't cause any confusion with alarms.
- Save the original chip configuration, and restore it on exit.
A later patch updates those interconversion routines to support
higher resolution measurements on chips which support them.
Signed-off-by: David Brownell <dbrownell at users.sourceforge.net>
---
drivers/hwmon/Kconfig | 9 +-
drivers/hwmon/lm75.c | 191 +++++++++++++++++++++++++++++++++++++-------------
2 files changed, 149 insertions(+), 51 deletions(-)
--- a/drivers/hwmon/Kconfig 2007-09-27 12:57:10.000000000 -0700
+++ b/drivers/hwmon/Kconfig 2007-09-27 13:50:47.000000000 -0700
@@ -312,9 +312,12 @@ config SENSORS_LM75
- TelCom (now Microchip) TCN75
- Texas Instruments TMP100, TMP101, TMP75, TMP175, TMP275
- 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.
+ This driver supports driver model based binding through board
+ specific I2C device tables.
+
+ It also supports the "legacy" style of driver binding. To use
+ that with some chips which don't replicate LM75 quirks exactly,
+ 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 2007-09-27 13:38:42.000000000 -0700
+++ b/drivers/hwmon/lm75.c 2007-09-27 14:26:44.000000000 -0700
@@ -54,18 +54,19 @@ static const u8 LM75_REG_TEMP[3] = {
/* Each client has this additional data */
struct lm75_data {
- struct i2c_client client;
+ struct i2c_client *client;
struct device *hwmon_dev;
struct mutex update_lock;
+ long min, max;
+ u8 orig_conf;
char valid; /* !=0 if registers are valid */
unsigned long last_updated; /* In jiffies */
- u16 temp[3]; /* Register values,
+ s16 temp[3]; /* Register values,
0 = input
1 = max
2 = hyst */
};
-static void lm75_init_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);
@@ -75,13 +76,28 @@ static struct lm75_data *lm75_update_dev
/* sysfs attributes for hwmon */
+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;
+
+ return LM75_TEMP_TO_REG(temp);
+}
+
+static inline int reg_to_temp(s16 reg)
+{
+ return LM75_TEMP_FROM_REG(reg);
+}
+
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,
@@ -94,7 +110,7 @@ static ssize_t set_temp(struct device *d
long temp = simple_strtol(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;
@@ -120,16 +136,112 @@ static const struct attribute_group lm75
/*-----------------------------------------------------------------------*/
+/* "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;
+
+ 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, 1/2 degree 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 */
+
+ data->min = -55 * 1000;
+ data->max = 125 * 1000;
+
+ /* for tmp175 or tmp275, use name "tmp75" */
+ 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_dev = hwmon_device_register(&client->dev);
+ if (IS_ERR(data->hwmon_dev)) {
+ status = PTR_ERR(data->hwmon_dev);
+ goto exit_remove;
+ }
+
+ dev_info(&client->dev, "%s: sensor '%s'\n",
+ data->hwmon_dev->bus_id, client->name);
+
+ return 0;
+
+exit_remove:
+ sysfs_remove_group(&client->dev.kobj, &lm75_group);
+exit_free:
+ i2c_set_clientdata(client, NULL);
+ kfree(data);
+ return status;
+}
+
+static int lm75_remove(struct i2c_client *client)
+{
+ struct lm75_data *data = i2c_get_clientdata(client);
+
+ hwmon_device_unregister(data->hwmon_dev);
+ sysfs_remove_group(&client->dev.kobj, &lm75_group);
+ lm75_write_value(client, LM75_REG_CONF, data->orig_conf);
+ i2c_set_clientdata(client, NULL);
+ kfree(data);
+ return 0;
+}
+
+static struct i2c_driver lm75_driver = {
+ .driver = {
+ .name = "lm75",
+ },
+ .probe = lm75_probe,
+ .remove = lm75_remove,
+};
+
+/*-----------------------------------------------------------------------*/
+
/* "Legacy" I2C driver binding */
-static struct i2c_driver lm75_driver;
+static struct i2c_driver lm75_legacy_driver;
/* 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;
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
@@ -139,16 +251,14 @@ static int lm75_detect(struct i2c_adapte
/* 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 i2c_smbus_read_*_data() calls. */
- if (!(data = kzalloc(sizeof(struct lm75_data), GFP_KERNEL))) {
+ if (!(new_client = kzalloc(sizeof *new_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-
@@ -189,38 +299,24 @@ static int lm75_detect(struct i2c_adapte
goto exit_free;
}
- /* NOTE: we treat "force=..." and "force_lm75=..." the same. */
+ /* NOTE: we treat "force=..." and "force_lm75=..." the same.
+ * Only new-style driver binding distinguishes chip types.
+ */
strlcpy(new_client->name, "lm75", I2C_NAME_SIZE);
- /* Fill in the remaining client fields and put it into the global list */
- 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->hwmon_dev = hwmon_device_register(&new_client->dev);
- if (IS_ERR(data->hwmon_dev)) {
- err = PTR_ERR(data->hwmon_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;
}
@@ -234,17 +330,15 @@ static int lm75_attach_adapter(struct i2
static int lm75_detach_client(struct i2c_client *client)
{
- struct lm75_data *data = i2c_get_clientdata(client);
- hwmon_device_unregister(data->hwmon_dev);
- sysfs_remove_group(&client->dev.kobj, &lm75_group);
+ lm75_remove(client);
i2c_detach_client(client);
- kfree(data);
+ kfree(client);
return 0;
}
-static struct i2c_driver lm75_driver = {
+static struct i2c_driver lm75_legacy_driver = {
.driver = {
- .name = "lm75",
+ .name = "lm75_legacy",
},
.attach_adapter = lm75_attach_adapter,
.detach_client = lm75_detach_client,
@@ -273,16 +367,6 @@ 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);
@@ -313,11 +397,22 @@ static struct lm75_data *lm75_update_dev
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);
}
