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Merge branch 'i2c-mux/for-next' of https://github.com/peda-r/i2c-mux into i2c/for-4.17

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"These patches verify the device id of the PCA984x mux chips using
standardized (but rarely implemented) i2c device identification."
This commit is contained in:
Wolfram Sang 2018-03-17 21:11:23 +01:00
commit 8efb11adee
3 changed files with 112 additions and 6 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
@ -1976,6 +1978,37 @@ 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!

55
drivers/i2c/muxes/i2c-mux-pca954x.c
View File

@ -77,6 +77,7 @@ struct chip_desc {
pca954x_ismux = 0,
pca954x_isswi
} muxtype;
struct i2c_device_identity id;
};
struct pca954x {
@ -97,59 +98,83 @@ static const struct chip_desc chips[] = {
.nchans = 2,
.enable = 0x4,
.muxtype = pca954x_ismux,
.id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
},
[pca_9542] = {
.nchans = 2,
.enable = 0x4,
.has_irq = 1,
.muxtype = pca954x_ismux,
.id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
},
[pca_9543] = {
.nchans = 2,
.has_irq = 1,
.muxtype = pca954x_isswi,
.id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
},
[pca_9544] = {
.nchans = 4,
.enable = 0x4,
.has_irq = 1,
.muxtype = pca954x_ismux,
.id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
},
[pca_9545] = {
.nchans = 4,
.has_irq = 1,
.muxtype = pca954x_isswi,
.id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
},
[pca_9546] = {
.nchans = 4,
.muxtype = pca954x_isswi,
.id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
},
[pca_9547] = {
.nchans = 8,
.enable = 0x8,
.muxtype = pca954x_ismux,
.id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
},
[pca_9548] = {
.nchans = 8,
.muxtype = pca954x_isswi,
.id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
},
[pca_9846] = {
.nchans = 4,
.muxtype = pca954x_isswi,
.id = {
.manufacturer_id = I2C_DEVICE_ID_NXP_SEMICONDUCTORS,
.part_id = 0x10b,
},
},
[pca_9847] = {
.nchans = 8,
.enable = 0x8,
.muxtype = pca954x_ismux,
.id = {
.manufacturer_id = I2C_DEVICE_ID_NXP_SEMICONDUCTORS,
.part_id = 0x108,
},
},
[pca_9848] = {
.nchans = 8,
.muxtype = pca954x_isswi,
.id = {
.manufacturer_id = I2C_DEVICE_ID_NXP_SEMICONDUCTORS,
.part_id = 0x10a,
},
},
[pca_9849] = {
.nchans = 4,
.enable = 0x4,
.muxtype = pca954x_ismux,
.id = {
.manufacturer_id = I2C_DEVICE_ID_NXP_SEMICONDUCTORS,
.part_id = 0x109,
},
},
};
@ -369,6 +394,30 @@ static int pca954x_probe(struct i2c_client *client,
if (IS_ERR(gpio))
return PTR_ERR(gpio);
match = of_match_device(of_match_ptr(pca954x_of_match), &client->dev);
if (match)
data->chip = of_device_get_match_data(&client->dev);
else
data->chip = &chips[id->driver_data];
if (data->chip->id.manufacturer_id != I2C_DEVICE_ID_NONE) {
struct i2c_device_identity id;
ret = i2c_get_device_id(client, &id);
if (ret && ret != -EOPNOTSUPP)
return ret;
if (!ret &&
(id.manufacturer_id != data->chip->id.manufacturer_id ||
id.part_id != data->chip->id.part_id)) {
dev_warn(&client->dev,
"unexpected device id %03x-%03x-%x\n",
id.manufacturer_id, id.part_id,
id.die_revision);
return -ENODEV;
}
}
/* Write the mux register at addr to verify
* that the mux is in fact present. This also
* initializes the mux to disconnected state.
@ -378,12 +427,6 @@ static int pca954x_probe(struct i2c_client *client,
return -ENODEV;
}
match = of_match_device(of_match_ptr(pca954x_of_match), &client->dev);
if (match)
data->chip = of_device_get_match_data(&client->dev);
else
data->chip = &chips[id->driver_data];
data->last_chan = 0; /* force the first selection */
idle_disconnect_dt = of_node &&

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,