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authorPeter Rosin <peda@axentia.se>2018-01-22 10:40:02 +0300
committerPeter Rosin <peda@axentia.se>2018-03-06 12:57:59 +0300
commit2d74187d5b4e29776e151ffcc09bdaedfd46e002 (patch)
tree4b2a2db9d0e15e2984bf36bb87433ca3a6795757 /drivers/i2c/muxes
parentdde67eb1beebcd8493e7b30e74a80f0865ab7e36 (diff)
downloadlinux-2d74187d5b4e29776e151ffcc09bdaedfd46e002.tar.xz
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>
Diffstat (limited to 'drivers/i2c/muxes')
-rw-r--r--drivers/i2c/muxes/i2c-mux-pca954x.c55
1 files changed, 49 insertions, 6 deletions
diff --git a/drivers/i2c/muxes/i2c-mux-pca954x.c b/drivers/i2c/muxes/i2c-mux-pca954x.c
index fbb84c7ef282..09bafd3e68fa 100644
--- a/drivers/i2c/muxes/i2c-mux-pca954x.c
+++ b/drivers/i2c/muxes/i2c-mux-pca954x.c
@@ -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 &&