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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: Adrian Fiergolski <adrian.fiergolski@cern.ch>
Reviewed-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Peter Rosin <peda@axentia.se>
This commit is contained in:
Peter Rosin 2018-01-22 08:32:01 +01:00
parent 4a3928c6f8
commit dde67eb1be
2 changed files with 63 additions and 0 deletions
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33
drivers/i2c/i2c-core-base.c
View File

@ -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!

30
include/linux/i2c.h
View File

@ -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,