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i2c: mux: pca954x: verify the device id of the pca984x chips 

Make sure to not disallow the chips on adapters that are not capable
of reading the device id, but also make sure to check the device id
before writing to the chip.

Tested-by: Adrian Fiergolski <adrian.fiergolski@cern.ch>
Signed-off-by: Peter Rosin <peda@axentia.se>
This commit is contained in:
Peter Rosin 2018-01-22 08:40:02 +01:00
parent dde67eb1be
commit 2d74187d5b
1 changed files with 49 additions and 6 deletions
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55
drivers/i2c/muxes/i2c-mux-pca954x.c
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@ -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 &&