USB: otg/ulpi: improve ulpi phy detection.
Improve ulpi phy detection by utilizing the "scratch" register.
Allow unknown ulpi phy work without the need to hard-code the id.
Signed-off-by: Igor Grinberg <grinberg@compulab.co.il>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/otg/ulpi.c b/drivers/usb/otg/ulpi.c
index ccc8195..e0d2a5c 100644
--- a/drivers/usb/otg/ulpi.c
+++ b/drivers/usb/otg/ulpi.c
@@ -137,6 +137,32 @@
return ulpi_set_fc_flags(otg);
}
+static int ulpi_check_integrity(struct otg_transceiver *otg)
+{
+ int ret, i;
+ unsigned int val = 0x55;
+
+ for (i = 0; i < 2; i++) {
+ ret = otg_io_write(otg, val, ULPI_SCRATCH);
+ if (ret < 0)
+ return ret;
+
+ ret = otg_io_read(otg, ULPI_SCRATCH);
+ if (ret < 0)
+ return ret;
+
+ if (ret != val) {
+ pr_err("ULPI integrity check: failed!");
+ return -ENODEV;
+ }
+ val = val << 1;
+ }
+
+ pr_info("ULPI integrity check: passed.\n");
+
+ return 0;
+}
+
static int ulpi_init(struct otg_transceiver *otg)
{
int i, vid, pid, ret;
@@ -155,10 +181,13 @@
for (i = 0; i < ARRAY_SIZE(ulpi_ids); i++)
if (ulpi_ids[i] == ULPI_ID(vid, pid))
- return ulpi_set_flags(otg);
+ break;
- pr_err("ULPI ID does not match any known transceiver.\n");
- return -ENODEV;
+ ret = ulpi_check_integrity(otg);
+ if (ret)
+ return ret;
+
+ return ulpi_set_flags(otg);
}
static int ulpi_set_host(struct otg_transceiver *otg, struct usb_bus *host)