From dde67eb1beebcd8493e7b30e74a80f0865ab7e36 Mon Sep 17 00:00:00 2001 From: Peter Rosin Date: Mon, 22 Jan 2018 08:32:01 +0100 Subject: [PATCH] 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 . Tested-by: Adrian Fiergolski Reviewed-by: Wolfram Sang Signed-off-by: Peter Rosin --- drivers/i2c/i2c-core-base.c | 33 +++++++++++++++++++++++++++++++++ include/linux/i2c.h | 30 ++++++++++++++++++++++++++++++ 2 files changed, 63 insertions(+) diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c index 5a00bf443d06..aa03eeb43814 100644 --- a/drivers/i2c/i2c-core-base.c +++ b/drivers/i2c/i2c-core-base.c @@ -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! diff --git a/include/linux/i2c.h b/include/linux/i2c.h index 419a38e7c315..44ad14e016b5 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -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, -- 2.45.2