NFC: trf7970a: Handle extra byte in response to Type 5 RMB commands
The current versions of the trf7970a has an erratum where it returns
an extra byte in the response to 'Read Multiple Block' (RMB) commands.
This command is issued to Type 5 tags (i.e., ISO/IEC 15693 tags) by
the neard daemon.
To handle this, define a new Device Tree property,
't5t-rmb-extra-byte-quirk', which indicates that the associated
trf7970a device has this erratum. The trf7970a device driver
will then ensure that the response length to RMB commands is
reduced by one byte (for devices with the erratum).
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 aa6a333..85b4d86 100644
--- a/drivers/nfc/trf7970a.c
+++ b/drivers/nfc/trf7970a.c
@@ -149,6 +149,7 @@
*/
#define TRF7970A_QUIRK_IRQ_STATUS_READ BIT(0)
#define TRF7970A_QUIRK_EN2_MUST_STAY_LOW BIT(1)
+#define TRF7970A_QUIRK_T5T_RMB_EXTRA_BYTE BIT(2)
/* Direct commands */
#define TRF7970A_CMD_IDLE 0x00
@@ -446,6 +447,7 @@
u8 md_rf_tech;
u8 tx_cmd;
bool issue_eof;
+ bool adjust_resp_len;
int en2_gpio;
int en_gpio;
struct mutex lock;
@@ -626,6 +628,11 @@
trf->aborting = false;
}
+ if (trf->adjust_resp_len) {
+ skb_trim(trf->rx_skb, trf->rx_skb->len - 1);
+ trf->adjust_resp_len = false;
+ }
+
trf->cb(trf->ddev, trf->cb_arg, trf->rx_skb);
trf->rx_skb = NULL;
@@ -1429,10 +1436,15 @@
trf->iso_ctrl = iso_ctrl;
}
- if ((trf->framing == NFC_DIGITAL_FRAMING_ISO15693_T5T) &&
- trf7970a_is_iso15693_write_or_lock(req[1]) &&
- (req[0] & ISO15693_REQ_FLAG_OPTION))
- trf->issue_eof = true;
+ if (trf->framing == NFC_DIGITAL_FRAMING_ISO15693_T5T) {
+ if (trf7970a_is_iso15693_write_or_lock(req[1]) &&
+ (req[0] & ISO15693_REQ_FLAG_OPTION))
+ trf->issue_eof = true;
+ else if ((trf->quirks &
+ TRF7970A_QUIRK_T5T_RMB_EXTRA_BYTE) &&
+ (req[1] == ISO15693_CMD_READ_MULTIPLE_BLOCK))
+ trf->adjust_resp_len = true;
+ }
}
return 0;
@@ -1992,6 +2004,9 @@
return ret;
}
+ if (of_property_read_bool(np, "t5t-rmb-extra-byte-quirk"))
+ trf->quirks |= TRF7970A_QUIRK_T5T_RMB_EXTRA_BYTE;
+
if (of_property_read_bool(np, "irq-status-read-quirk"))
trf->quirks |= TRF7970A_QUIRK_IRQ_STATUS_READ;