i2c: Add support for device alias names

Based on earlier work by Jon Smirl and Jochen Friedrich.

This patch allows new-style i2c chip drivers to have alias names using
the official kernel aliasing system and MODULE_DEVICE_TABLE(). At this
point, the old i2c driver binding scheme (driver_name/type) is still
supported.

Signed-off-by: Jean Delvare <[e-mail]>
Cc: Jochen Friedrich <[e-mail]>
Cc: Jon Smirl <[e-mail]>
Cc: Kay Sievers <[e-mail]>

Documentation/i2c/writing-clients

···
 kind of driver in Linux:  they provide a probe() method to bind to
 those devices, and a remove() method to unbind.
 
-	static int foo_probe(struct i2c_client *client);
+	static int foo_probe(struct i2c_client *client,
+			     const struct i2c_device_id *id);
 	static int foo_remove(struct i2c_client *client);
 
 Remember that the i2c_driver does not create those client handles.  The

drivers/gpio/pca953x.c

···
 	gc->owner = THIS_MODULE;
 }
 
-static int __devinit pca953x_probe(struct i2c_client *client)
+static int __devinit pca953x_probe(struct i2c_client *client,
+				   const struct i2c_device_id *did)
 {
 	struct pca953x_platform_data *pdata;
 	struct pca953x_chip *chip;

drivers/gpio/pcf857x.c

···
 
 /*-------------------------------------------------------------------------*/
 
-static int pcf857x_probe(struct i2c_client *client)
+static int pcf857x_probe(struct i2c_client *client,
+			 const struct i2c_device_id *id)
 {
 	struct pcf857x_platform_data	*pdata;
 	struct pcf857x			*gpio;

drivers/hwmon/f75375s.c

···
 static int f75375_attach_adapter(struct i2c_adapter *adapter);
 static int f75375_detect(struct i2c_adapter *adapter, int address, int kind);
 static int f75375_detach_client(struct i2c_client *client);
-static int f75375_probe(struct i2c_client *client);
+static int f75375_probe(struct i2c_client *client,
+			const struct i2c_device_id *id);
 static int f75375_remove(struct i2c_client *client);
 
 static struct i2c_driver f75375_legacy_driver = {
···
 
 }
 
-static int f75375_probe(struct i2c_client *client)
+static int f75375_probe(struct i2c_client *client,
+		const struct i2c_device_id *id)
 {
 	struct f75375_data *data = i2c_get_clientdata(client);
 	struct f75375s_platform_data *f75375s_pdata = client->dev.platform_data;
···
 	if ((err = i2c_attach_client(client)))
 		goto exit_free;
 
-	if ((err = f75375_probe(client)) < 0)
+	if ((err = f75375_probe(client, NULL)) < 0)
 		goto exit_detach;
 
 	return 0;

drivers/i2c/chips/ds1682.c

···
 /*
  * Called when a ds1682 device is matched with this driver
  */
-static int ds1682_probe(struct i2c_client *client)
+static int ds1682_probe(struct i2c_client *client,
+			const struct i2c_device_id *id)
 {
 	int rc;
 

drivers/i2c/chips/menelaus.c

···
 
 static struct i2c_driver menelaus_i2c_driver;
 
-static int menelaus_probe(struct i2c_client *client)
+static int menelaus_probe(struct i2c_client *client,
+			  const struct i2c_device_id *id)
 {
 	struct menelaus_chip	*menelaus;
 	int			rev = 0, val;

drivers/i2c/chips/tps65010.c

···
 	return 0;
 }
 
-static int tps65010_probe(struct i2c_client *client)
+static int tps65010_probe(struct i2c_client *client,
+			  const struct i2c_device_id *id)
 {
 	struct tps65010		*tps;
 	int			status;

drivers/i2c/chips/tsl2550.c

···
  */
 
 static struct i2c_driver tsl2550_driver;
-static int __devinit tsl2550_probe(struct i2c_client *client)
+static int __devinit tsl2550_probe(struct i2c_client *client,
+				   const struct i2c_device_id *id)
 {
 	struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
 	struct tsl2550_data *data;

drivers/i2c/i2c-core.c

···
 
 /* ------------------------------------------------------------------------- */
 
+static const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id,
+						const struct i2c_client *client)
+{
+	while (id->name[0]) {
+		if (strcmp(client->name, id->name) == 0)
+			return id;
+		id++;
+	}
+	return NULL;
+}
+
 static int i2c_device_match(struct device *dev, struct device_driver *drv)
 {
 	struct i2c_client	*client = to_i2c_client(dev);
···
 	 */
 	if (!is_newstyle_driver(driver))
 		return 0;
+
+	/* match on an id table if there is one */
+	if (driver->id_table)
+		return i2c_match_id(driver->id_table, client) != NULL;
 
 	/* new style drivers use the same kind of driver matching policy
 	 * as platform devices or SPI:  compare device and driver IDs.
···
 	struct i2c_client	*client = to_i2c_client(dev);
 
 	/* by definition, legacy drivers can't hotplug */
-	if (dev->driver || !client->driver_name)
+	if (dev->driver)
 		return 0;
 
-	if (add_uevent_var(env, "MODALIAS=%s", client->driver_name))
-		return -ENOMEM;
+	if (client->driver_name[0]) {
+		if (add_uevent_var(env, "MODALIAS=%s", client->driver_name))
+			return -ENOMEM;
+	} else {
+		if (add_uevent_var(env, "MODALIAS=%s%s",
+				   I2C_MODULE_PREFIX, client->name))
+			return -ENOMEM;
+	}
 	dev_dbg(dev, "uevent\n");
 	return 0;
 }
···
 {
 	struct i2c_client	*client = to_i2c_client(dev);
 	struct i2c_driver	*driver = to_i2c_driver(dev->driver);
+	const struct i2c_device_id *id;
 	int status;
 
 	if (!driver->probe)
 		return -ENODEV;
 	client->driver = driver;
 	dev_dbg(dev, "probe\n");
-	status = driver->probe(client);
+
+	if (driver->id_table)
+		id = i2c_match_id(driver->id_table, client);
+	else
+		id = NULL;
+	status = driver->probe(client, id);
 	if (status)
 		client->driver = NULL;
 	return status;
···
 static ssize_t show_modalias(struct device *dev, struct device_attribute *attr, char *buf)
 {
 	struct i2c_client *client = to_i2c_client(dev);
-	return client->driver_name
+	return client->driver_name[0]
 		? sprintf(buf, "%s\n", client->driver_name)
-		: 0;
+		: sprintf(buf, "%s%s\n", I2C_MODULE_PREFIX, client->name);
 }
 
 static struct device_attribute i2c_dev_attrs[] = {
···
 EXPORT_SYMBOL_GPL(i2c_unregister_device);
 
 
-static int dummy_nop(struct i2c_client *client)
+static int dummy_probe(struct i2c_client *client,
+		       const struct i2c_device_id *id)
+{
+	return 0;
+}
+
+static int dummy_remove(struct i2c_client *client)
 {
 	return 0;
 }
 
 static struct i2c_driver dummy_driver = {
 	.driver.name	= "dummy",
-	.probe		= dummy_nop,
-	.remove		= dummy_nop,
+	.probe		= dummy_probe,
+	.remove		= dummy_remove,
 };
 
 /**

drivers/media/video/cs5345.c

···
 
 /* ----------------------------------------------------------------------- */
 
-static int cs5345_probe(struct i2c_client *client)
+static int cs5345_probe(struct i2c_client *client,
+			const struct i2c_device_id *id)
 {
 	/* Check if the adapter supports the needed features */
 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))

drivers/media/video/cs53l32a.c

···
  * concerning the addresses: i2c wants 7 bit (without the r/w bit), so '>>1'
  */
 
-static int cs53l32a_probe(struct i2c_client *client)
+static int cs53l32a_probe(struct i2c_client *client,
+			  const struct i2c_device_id *id)
 {
 	int i;
 

drivers/media/video/cx25840/cx25840-core.c

···
 
 /* ----------------------------------------------------------------------- */
 
-static int cx25840_probe(struct i2c_client *client)
+static int cx25840_probe(struct i2c_client *client,
+			 const struct i2c_device_id *did)
 {
 	struct cx25840_state *state;
 	u32 id;

drivers/media/video/m52790.c

···
 
 /* i2c implementation */
 
-static int m52790_probe(struct i2c_client *client)
+static int m52790_probe(struct i2c_client *client,
+			const struct i2c_device_id *id)
 {
 	struct m52790_state *state;
 

drivers/media/video/msp3400-driver.c

···
 
 /* ----------------------------------------------------------------------- */
 
-static int msp_probe(struct i2c_client *client)
+static int msp_probe(struct i2c_client *client, const struct i2c_device_id *id)
 {
 	struct msp_state *state;
 	int (*thread_func)(void *data) = NULL;

drivers/media/video/mt9m001.c

···
 	soc_camera_video_stop(&mt9m001->icd);
 }
 
-static int mt9m001_probe(struct i2c_client *client)
+static int mt9m001_probe(struct i2c_client *client,
+			 const struct i2c_device_id *did)
 {
 	struct mt9m001 *mt9m001;
 	struct soc_camera_device *icd;

drivers/media/video/mt9v022.c

···
 	soc_camera_video_stop(&mt9v022->icd);
 }
 
-static int mt9v022_probe(struct i2c_client *client)
+static int mt9v022_probe(struct i2c_client *client,
+			 const struct i2c_device_id *did)
 {
 	struct mt9v022 *mt9v022;
 	struct soc_camera_device *icd;

drivers/media/video/saa7115.c

···
 
 /* ----------------------------------------------------------------------- */
 
-static int saa7115_probe(struct i2c_client *client)
+static int saa7115_probe(struct i2c_client *client,
+			 const struct i2c_device_id *id)
 {
 	struct saa711x_state *state;
 	int	i;

drivers/media/video/saa7127.c

···
 
 /* ----------------------------------------------------------------------- */
 
-static int saa7127_probe(struct i2c_client *client)
+static int saa7127_probe(struct i2c_client *client,
+			 const struct i2c_device_id *id)
 {
 	struct saa7127_state *state;
 	struct v4l2_sliced_vbi_data vbi = { 0, 0, 0, 0 };  /* set to disabled */

drivers/media/video/saa717x.c

···
 /* i2c implementation */
 
 /* ----------------------------------------------------------------------- */
-static int saa717x_probe(struct i2c_client *client)
+static int saa717x_probe(struct i2c_client *client,
+			 const struct i2c_device_id *did)
 {
 	struct saa717x_state *decoder;
 	u8 id = 0;

drivers/media/video/tcm825x.c

···
 	},
 };
 
-static int tcm825x_probe(struct i2c_client *client)
+static int tcm825x_probe(struct i2c_client *client,
+			 const struct i2c_device_id *did)
 {
 	struct tcm825x_sensor *sensor = &tcm825x;
 	int rval;

drivers/media/video/tlv320aic23b.c

···
  * concerning the addresses: i2c wants 7 bit (without the r/w bit), so '>>1'
  */
 
-static int tlv320aic23b_probe(struct i2c_client *client)
+static int tlv320aic23b_probe(struct i2c_client *client,
+			      const struct i2c_device_id *id)
 {
 	struct tlv320aic23b_state *state;
 

drivers/media/video/tuner-core.c

···
 /* During client attach, set_type is called by adapter's attach_inform callback.
    set_type must then be completed by tuner_probe.
  */
-static int tuner_probe(struct i2c_client *client)
+static int tuner_probe(struct i2c_client *client,
+		       const struct i2c_device_id *id)
 {
 	struct tuner *t;
 	struct tuner *radio;

drivers/media/video/tvaudio.c

···
 /* ---------------------------------------------------------------------- */
 /* i2c registration                                                       */
 
-static int chip_probe(struct i2c_client *client)
+static int chip_probe(struct i2c_client *client, const struct i2c_device_id *id)
 {
 	struct CHIPSTATE *chip;
 	struct CHIPDESC  *desc;

drivers/media/video/upd64031a.c

···
 
 /* i2c implementation */
 
-static int upd64031a_probe(struct i2c_client *client)
+static int upd64031a_probe(struct i2c_client *client,
+			   const struct i2c_device_id *id)
 {
 	struct upd64031a_state *state;
 	int i;

drivers/media/video/upd64083.c

···
 
 /* i2c implementation */
 
-static int upd64083_probe(struct i2c_client *client)
+static int upd64083_probe(struct i2c_client *client,
+			  const struct i2c_device_id *id)
 {
 	struct upd64083_state *state;
 	int i;

drivers/media/video/v4l2-common.c

···
 /* Helper function for I2C legacy drivers */
 
 int v4l2_i2c_attach(struct i2c_adapter *adapter, int address, struct i2c_driver *driver,
-		const char *name, int (*probe)(struct i2c_client *))
+		const char *name,
+		int (*probe)(struct i2c_client *, const struct i2c_device_id *))
 {
 	struct i2c_client *client;
 	int err;
···
 	client->driver = driver;
 	strlcpy(client->name, name, sizeof(client->name));
 
-	err = probe(client);
+	err = probe(client, NULL);
 	if (err == 0) {
 		i2c_attach_client(client);
 	} else {

drivers/media/video/vp27smpx.c

···
  * concerning the addresses: i2c wants 7 bit (without the r/w bit), so '>>1'
  */
 
-static int vp27smpx_probe(struct i2c_client *client)
+static int vp27smpx_probe(struct i2c_client *client,
+			  const struct i2c_device_id *id)
 {
 	struct vp27smpx_state *state;
 

drivers/media/video/wm8739.c

···
 
 /* i2c implementation */
 
-static int wm8739_probe(struct i2c_client *client)
+static int wm8739_probe(struct i2c_client *client,
+			const struct i2c_device_id *id)
 {
 	struct wm8739_state *state;
 

drivers/media/video/wm8775.c

···
  * concerning the addresses: i2c wants 7 bit (without the r/w bit), so '>>1'
  */
 
-static int wm8775_probe(struct i2c_client *client)
+static int wm8775_probe(struct i2c_client *client,
+			const struct i2c_device_id *id)
 {
 	struct wm8775_state *state;
 

drivers/rtc/rtc-ds1307.c

···
 
 static struct i2c_driver ds1307_driver;
 
-static int __devinit ds1307_probe(struct i2c_client *client)
+static int __devinit ds1307_probe(struct i2c_client *client,
+				  const struct i2c_device_id *id)
 {
 	struct ds1307		*ds1307;
 	int			err = -ENODEV;

drivers/rtc/rtc-ds1374.c

···
 	.ioctl = ds1374_ioctl,
 };
 
-static int ds1374_probe(struct i2c_client *client)
+static int ds1374_probe(struct i2c_client *client,
+			const struct i2c_device_id *id)
 {
 	struct ds1374 *ds1374;
 	int ret;

drivers/rtc/rtc-isl1208.c

···
 }
 
 static int
-isl1208_probe(struct i2c_client *client)
+isl1208_probe(struct i2c_client *client, const struct i2c_device_id *id)
 {
 	int rc = 0;
 	struct rtc_device *rtc;

drivers/rtc/rtc-m41t80.c

···
  *
  *****************************************************************************
  */
-static int m41t80_probe(struct i2c_client *client)
+static int m41t80_probe(struct i2c_client *client,
+			const struct i2c_device_id *id)
 {
 	int i, rc = 0;
 	struct rtc_device *rtc = NULL;

drivers/rtc/rtc-pcf8563.c

···
 	.set_time	= pcf8563_rtc_set_time,
 };
 
-static int pcf8563_probe(struct i2c_client *client)
+static int pcf8563_probe(struct i2c_client *client,
+				const struct i2c_device_id *id)
 {
 	struct pcf8563 *pcf8563;
 

drivers/rtc/rtc-rs5c372.c

···
 
 static struct i2c_driver rs5c372_driver;
 
-static int rs5c372_probe(struct i2c_client *client)
+static int rs5c372_probe(struct i2c_client *client,
+			 const struct i2c_device_id *id)
 {
 	int err = 0;
 	struct rs5c372 *rs5c372;

drivers/rtc/rtc-s35390a.c

···
 
 static struct i2c_driver s35390a_driver;
 
-static int s35390a_probe(struct i2c_client *client)
+static int s35390a_probe(struct i2c_client *client,
+			 const struct i2c_device_id *id)
 {
 	int err;
 	unsigned int i;

drivers/rtc/rtc-x1205.c

···
 }
 
 
-static int x1205_probe(struct i2c_client *client)
+static int x1205_probe(struct i2c_client *client,
+			const struct i2c_device_id *id)
 {
 	int err = 0;
 	unsigned char sr;

include/linux/i2c.h

···
 	 * With the driver model, device enumeration is NEVER done by drivers;
 	 * it's done by infrastructure.  (NEW STYLE DRIVERS ONLY)
 	 */
-	int (*probe)(struct i2c_client *);
+	int (*probe)(struct i2c_client *, const struct i2c_device_id *);
 	int (*remove)(struct i2c_client *);
 
 	/* driver model interfaces that don't relate to enumeration  */
···
 	int (*command)(struct i2c_client *client,unsigned int cmd, void *arg);
 
 	struct device_driver driver;
+	const struct i2c_device_id *id_table;
 };
 #define to_i2c_driver(d) container_of(d, struct i2c_driver, driver)
-
-#define I2C_NAME_SIZE	20
 
 /**
  * struct i2c_client - represent an I2C slave device

include/linux/mod_devicetable.h

···
 };
 #define VIRTIO_DEV_ANY_ID	0xffffffff
 
+/* i2c */
+
+#define I2C_NAME_SIZE	20
+#define I2C_MODULE_PREFIX "i2c:"
+
+struct i2c_device_id {
+	char name[I2C_NAME_SIZE];
+	kernel_ulong_t driver_data;	/* Data private to the driver */
+};
+
+
 #endif /* LINUX_MOD_DEVICETABLE_H */

include/media/v4l2-common.h

···
 struct i2c_driver;
 struct i2c_adapter;
 struct i2c_client;
+struct i2c_device_id;
 
 int v4l2_i2c_attach(struct i2c_adapter *adapter, int address, struct i2c_driver *driver,
-		const char *name, int (*probe)(struct i2c_client *));
+		const char *name,
+		int (*probe)(struct i2c_client *, const struct i2c_device_id *));
 
 /* ------------------------------------------------------------------------- */
 

include/media/v4l2-i2c-drv-legacy.h

···
 	const char * const name;
 	int driverid;
 	int (*command)(struct i2c_client *client, unsigned int cmd, void *arg);
-	int (*probe)(struct i2c_client *client);
+	int (*probe)(struct i2c_client *client, const struct i2c_device_id *id);
 	int (*remove)(struct i2c_client *client);
 	int (*suspend)(struct i2c_client *client, pm_message_t state);
 	int (*resume)(struct i2c_client *client);

include/media/v4l2-i2c-drv.h

···
 	const char * const name;
 	int driverid;
 	int (*command)(struct i2c_client *client, unsigned int cmd, void *arg);
-	int (*probe)(struct i2c_client *client);
+	int (*probe)(struct i2c_client *client, const struct i2c_device_id *id);
 	int (*remove)(struct i2c_client *client);
 	int (*suspend)(struct i2c_client *client, pm_message_t state);
 	int (*resume)(struct i2c_client *client);

scripts/mod/file2alias.c

···
 	return 1;
 }
 
+/* Looks like: i2c:S */
+static int do_i2c_entry(const char *filename, struct i2c_device_id *id,
+			char *alias)
+{
+	sprintf(alias, I2C_MODULE_PREFIX "%s", id->name);
+
+	return 1;
+}
+
 /* Ignore any prefix, eg. v850 prepends _ */
 static inline int sym_is(const char *symbol, const char *name)
 {
···
 		do_table(symval, sym->st_size,
 			 sizeof(struct virtio_device_id), "virtio",
 			 do_virtio_entry, mod);
+	else if (sym_is(symname, "__mod_i2c_device_table"))
+		do_table(symval, sym->st_size,
+			 sizeof(struct i2c_device_id), "i2c",
+			 do_i2c_entry, mod);
 	free(zeros);
 }