diff options
| author | Konrad Dybcio <[email protected]> | 2024-07-29 10:42:58 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <[email protected]> | 2024-07-31 10:39:34 +0200 |
| commit | e885f5f1f2b43575aa8e4e31404132d77d6663d1 (patch) | |
| tree | 3fdfed7c465241a43e5edd65ec1bea6d821ff1df | |
| parent | 973a57891608a98e894db2887f278777f564de18 (diff) | |
usb: typec: fsa4480: Check if the chip is really there
Currently, the driver will happily register the switch/mux devices, and
so long as the i2c master doesn't complain, the user would never know
there's something wrong.
Add a device id check (based on [1]) and return -ENODEV if the read
fails or returns nonsense.
Checking the value on a Qualcomm SM6115P-based Lenovo Tab P11 tablet,
the ID mentioned in the datasheet does indeed show up:
fsa4480 1-0042: Found FSA4480 v1.1 (Vendor ID = 0)
[1] https://www.onsemi.com/pdf/datasheet/fsa4480-d.pdf
Fixes: 1dc246320c6b ("usb: typec: mux: Add On Semi fsa4480 driver")
Cc: stable <[email protected]>
Reviewed-by: Dmitry Baryshkov <[email protected]>
Signed-off-by: Konrad Dybcio <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
| -rw-r--r-- | drivers/usb/typec/mux/fsa4480.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/drivers/usb/typec/mux/fsa4480.c b/drivers/usb/typec/mux/fsa4480.c index cb7cdf90cb0a..cd235339834b 100644 --- a/drivers/usb/typec/mux/fsa4480.c +++ b/drivers/usb/typec/mux/fsa4480.c @@ -13,6 +13,10 @@ #include <linux/usb/typec_dp.h> #include <linux/usb/typec_mux.h> +#define FSA4480_DEVICE_ID 0x00 + #define FSA4480_DEVICE_ID_VENDOR_ID GENMASK(7, 6) + #define FSA4480_DEVICE_ID_VERSION_ID GENMASK(5, 3) + #define FSA4480_DEVICE_ID_REV_ID GENMASK(2, 0) #define FSA4480_SWITCH_ENABLE 0x04 #define FSA4480_SWITCH_SELECT 0x05 #define FSA4480_SWITCH_STATUS1 0x07 @@ -251,6 +255,7 @@ static int fsa4480_probe(struct i2c_client *client) struct typec_switch_desc sw_desc = { }; struct typec_mux_desc mux_desc = { }; struct fsa4480 *fsa; + int val = 0; int ret; fsa = devm_kzalloc(dev, sizeof(*fsa), GFP_KERNEL); @@ -268,6 +273,15 @@ static int fsa4480_probe(struct i2c_client *client) if (IS_ERR(fsa->regmap)) return dev_err_probe(dev, PTR_ERR(fsa->regmap), "failed to initialize regmap\n"); + ret = regmap_read(fsa->regmap, FSA4480_DEVICE_ID, &val); + if (ret || !val) + return dev_err_probe(dev, -ENODEV, "FSA4480 not found\n"); + + dev_dbg(dev, "Found FSA4480 v%lu.%lu (Vendor ID = %lu)\n", + FIELD_GET(FSA4480_DEVICE_ID_VERSION_ID, val), + FIELD_GET(FSA4480_DEVICE_ID_REV_ID, val), + FIELD_GET(FSA4480_DEVICE_ID_VENDOR_ID, val)); + /* Safe mode */ fsa->cur_enable = FSA4480_ENABLE_DEVICE | FSA4480_ENABLE_USB; fsa->mode = TYPEC_STATE_SAFE; |