Commit dde67eb1 authored by Peter Rosin's avatar Peter Rosin
Browse files

i2c: add i2c_get_device_id() to get the standard i2c device id 



Can be used during probe to double check that the probed device is
what is expected.

Loosely based on code from Adrian Fiergolski <adrian.fiergolski@cern.ch>.

Tested-by: default avatarAdrian Fiergolski <adrian.fiergolski@cern.ch>
Reviewed-by: default avatarWolfram Sang <wsa@the-dreams.de>
Signed-off-by: default avatarPeter Rosin <peda@axentia.se>
parent 4a3928c6

drivers/i2c/i2c-core-base.c

+33 −0
Original line number Diff line number Diff line
@@ -58,6 +58,8 @@ 
#define I2C_ADDR_7BITS_MAX	0x77

#define I2C_ADDR_7BITS_COUNT	(I2C_ADDR_7BITS_MAX + 1)



#define I2C_ADDR_DEVICE_ID	0x7c



/*

 * core_lock protects i2c_adapter_idr, and guarantees that device detection,

 * deletion of detected devices, and attach_adapter calls are serialized
@@ -1968,6 +1970,37 @@ int i2c_transfer_buffer_flags(const struct i2c_client *client, char *buf, 
}

EXPORT_SYMBOL(i2c_transfer_buffer_flags);



/**

 * i2c_get_device_id - get manufacturer, part id and die revision of a device

 * @client: The device to query

 * @id: The queried information

 *

 * Returns negative errno on error, zero on success.

 */

int i2c_get_device_id(const struct i2c_client *client,

		      struct i2c_device_identity *id)

{

	struct i2c_adapter *adap = client->adapter;

	union i2c_smbus_data raw_id;

	int ret;



	if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_I2C_BLOCK))

		return -EOPNOTSUPP;



	raw_id.block[0] = 3;

	ret = i2c_smbus_xfer(adap, I2C_ADDR_DEVICE_ID, 0,

			     I2C_SMBUS_READ, client->addr << 1,

			     I2C_SMBUS_I2C_BLOCK_DATA, &raw_id);

	if (ret)

		return ret;



	id->manufacturer_id = (raw_id.block[1] << 4) | (raw_id.block[2] >> 4);

	id->part_id = ((raw_id.block[2] & 0xf) << 5) | (raw_id.block[3] >> 3);

	id->die_revision = raw_id.block[3] & 0x7;

	return 0;

}

EXPORT_SYMBOL_GPL(i2c_get_device_id);



/* ----------------------------------------------------

 * the i2c address scanning function

 * Will not work for 10-bit addresses!

include/linux/i2c.h

+30 −0
Original line number Diff line number Diff line
@@ -47,6 +47,7 @@ struct i2c_algorithm; 
struct i2c_adapter;

struct i2c_client;

struct i2c_driver;

struct i2c_device_identity;

union i2c_smbus_data;

struct i2c_board_info;

enum i2c_slave_event;
@@ -186,8 +187,37 @@ extern s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client, 
extern s32

i2c_smbus_read_i2c_block_data_or_emulated(const struct i2c_client *client,

					  u8 command, u8 length, u8 *values);

int i2c_get_device_id(const struct i2c_client *client,

		      struct i2c_device_identity *id);

#endif /* I2C */



/**

 * struct i2c_device_identity - i2c client device identification

 * @manufacturer_id: 0 - 4095, database maintained by NXP

 * @part_id: 0 - 511, according to manufacturer

 * @die_revision: 0 - 7, according to manufacturer

 */

struct i2c_device_identity {

	u16 manufacturer_id;

#define I2C_DEVICE_ID_NXP_SEMICONDUCTORS                0

#define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_1              1

#define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_2              2

#define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_3              3

#define I2C_DEVICE_ID_RAMTRON_INTERNATIONAL             4

#define I2C_DEVICE_ID_ANALOG_DEVICES                    5

#define I2C_DEVICE_ID_STMICROELECTRONICS                6

#define I2C_DEVICE_ID_ON_SEMICONDUCTOR                  7

#define I2C_DEVICE_ID_SPRINTEK_CORPORATION              8

#define I2C_DEVICE_ID_ESPROS_PHOTONICS_AG               9

#define I2C_DEVICE_ID_FUJITSU_SEMICONDUCTOR            10

#define I2C_DEVICE_ID_FLIR                             11

#define I2C_DEVICE_ID_O2MICRO                          12

#define I2C_DEVICE_ID_ATMEL                            13

#define I2C_DEVICE_ID_NONE                         0xffff

	u16 part_id;

	u8 die_revision;

};



enum i2c_alert_protocol {

	I2C_PROTOCOL_SMBUS_ALERT,

	I2C_PROTOCOL_SMBUS_HOST_NOTIFY,