NFC: add hw reset before testing hw presence.
Need to reset the NFCC to guarantee that its i2c interface is up.
Change-Id: I4d07ecb0756a0d0afe0a65551f51a253a3c7b6b5
Signed-off-by: Houston Hoffman <hhoffman@codeaurora.org>
diff --git a/drivers/nfc/nfc-nci.c b/drivers/nfc/nfc-nci.c
index 232167c..5ac93b6 100644
--- a/drivers/nfc/nfc-nci.c
+++ b/drivers/nfc/nfc-nci.c
@@ -1253,8 +1253,12 @@
goto err_free_dev;
}
- /* Put device in ULPM */
- gpio_set_value(platform_data->dis_gpio, 0);
+ /* Guarantee that the NFCC starts in a clean state. */
+ gpio_set_value(platform_data->dis_gpio, 1);/* HPD */
+ usleep(200);
+ gpio_set_value(platform_data->dis_gpio, 0);/* ULPM */
+ usleep(200);
+
r = nfcc_hw_check(client, platform_data->reg);
if (r) {
/* We don't think there is hardware but just in case HPD */