NFC: trf7970a: Turn RF on after hardware is configured
The NFC digital layer calls the 'switch_rf' hook to turn the RF on before
it configures the RF technology and framing. There is potential to confuse
a tag doing it this way so don't enable the RF until the RF technology and
initial framing have been configured.
Signed-off-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/drivers/nfc/trf7970a.c b/drivers/nfc/trf7970a.c
index 203d86f..0a46348 100644
--- a/drivers/nfc/trf7970a.c
+++ b/drivers/nfc/trf7970a.c
@@ -779,11 +779,6 @@
trf->special_fcn_reg1 = 0;
- ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
- trf->chip_status_ctrl | TRF7970A_CHIP_STATUS_RF_ON);
- if (ret)
- goto err_out;
-
trf->iso_ctrl = 0xff;
return 0;
@@ -796,6 +791,10 @@
{
dev_dbg(trf->dev, "Switching rf off\n");
+ trf->chip_status_ctrl &= ~TRF7970A_CHIP_STATUS_RF_ON;
+
+ trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL, trf->chip_status_ctrl);
+
gpio_set_value(trf->en_gpio, 0);
gpio_set_value(trf->en2_gpio, 0);
@@ -948,6 +947,18 @@
return ret;
}
+ if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) {
+ ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
+ trf->chip_status_ctrl |
+ TRF7970A_CHIP_STATUS_RF_ON);
+ if (ret)
+ return ret;
+
+ trf->chip_status_ctrl |= TRF7970A_CHIP_STATUS_RF_ON;
+
+ usleep_range(5000, 6000);
+ }
+
return 0;
}