u8 curr_protocol;
u8 curr_rf_tech;
u8 curr_nfc_dep_pni;
+
+ int (*skb_check_crc)(struct sk_buff *skb);
+ void (*skb_add_crc)(struct sk_buff *skb);
};
struct nfc_digital_dev *nfc_digital_allocate_device(struct nfc_digital_ops *ops,
config NFC_DIGITAL
depends on NFC
+ select CRC_CCITT
tristate "NFC Digital Protocol stack support"
default n
help
#include <net/nfc/nfc.h>
#include <net/nfc/digital.h>
+#include <linux/crc-ccitt.h>
+
#define PR_DBG(fmt, ...) pr_debug("%s: " fmt "\n", __func__, ##__VA_ARGS__)
#define PR_ERR(fmt, ...) pr_err("%s: " fmt "\n", __func__, ##__VA_ARGS__)
#define PROTOCOL_ERR(req) pr_err("%s:%d: NFC Digital Protocol error: %s\n", \
#define DIGITAL_MAX_HEADER_LEN 7
#define DIGITAL_CRC_LEN 2
+#define DIGITAL_DRV_CAPS_IN_CRC(ddev) \
+ ((ddev)->driver_capabilities & NFC_DIGITAL_DRV_CAPS_IN_CRC)
+#define DIGITAL_DRV_CAPS_TG_CRC(ddev) \
+ ((ddev)->driver_capabilities & NFC_DIGITAL_DRV_CAPS_TG_CRC)
+
+struct digital_data_exch {
+ data_exchange_cb_t cb;
+ void *cb_context;
+};
+
struct sk_buff *digital_skb_alloc(struct nfc_digital_dev *ddev,
unsigned int len);
int digital_in_send_sens_req(struct nfc_digital_dev *ddev, u8 rf_tech);
+int digital_target_found(struct nfc_digital_dev *ddev,
+ struct nfc_target *target, u8 protocol);
+
+int digital_in_recv_mifare_res(struct sk_buff *resp);
+
+typedef u16 (*crc_func_t)(u16, const u8 *, size_t);
+
+#define CRC_A_INIT 0x6363
+#define CRC_B_INIT 0xFFFF
+
+void digital_skb_add_crc(struct sk_buff *skb, crc_func_t crc_func, u16 init,
+ u8 bitwise_inv, u8 msb_first);
+
+static inline void digital_skb_add_crc_a(struct sk_buff *skb)
+{
+ digital_skb_add_crc(skb, crc_ccitt, CRC_A_INIT, 0, 0);
+}
+
+static inline void digital_skb_add_crc_b(struct sk_buff *skb)
+{
+ digital_skb_add_crc(skb, crc_ccitt, CRC_B_INIT, 1, 0);
+}
+
+static inline void digital_skb_add_crc_none(struct sk_buff *skb)
+{
+ return;
+}
+
+int digital_skb_check_crc(struct sk_buff *skb, crc_func_t crc_func,
+ u16 crc_init, u8 bitwise_inv, u8 msb_first);
+
+static inline int digital_skb_check_crc_a(struct sk_buff *skb)
+{
+ return digital_skb_check_crc(skb, crc_ccitt, CRC_A_INIT, 0, 0);
+}
+
+static inline int digital_skb_check_crc_b(struct sk_buff *skb)
+{
+ return digital_skb_check_crc(skb, crc_ccitt, CRC_B_INIT, 1, 0);
+}
+
+static inline int digital_skb_check_crc_none(struct sk_buff *skb)
+{
+ return 0;
+}
+
#endif /* __DIGITAL_H */
return skb;
}
+void digital_skb_add_crc(struct sk_buff *skb, crc_func_t crc_func, u16 init,
+ u8 bitwise_inv, u8 msb_first)
+{
+ u16 crc;
+
+ crc = crc_func(init, skb->data, skb->len);
+
+ if (bitwise_inv)
+ crc = ~crc;
+
+ if (msb_first)
+ crc = __fswab16(crc);
+
+ *skb_put(skb, 1) = crc & 0xFF;
+ *skb_put(skb, 1) = (crc >> 8) & 0xFF;
+}
+
+int digital_skb_check_crc(struct sk_buff *skb, crc_func_t crc_func,
+ u16 crc_init, u8 bitwise_inv, u8 msb_first)
+{
+ int rc;
+ u16 crc;
+
+ if (skb->len <= 2)
+ return -EIO;
+
+ crc = crc_func(crc_init, skb->data, skb->len - 2);
+
+ if (bitwise_inv)
+ crc = ~crc;
+
+ if (msb_first)
+ crc = __swab16(crc);
+
+ rc = (skb->data[skb->len - 2] - (crc & 0xFF)) +
+ (skb->data[skb->len - 1] - ((crc >> 8) & 0xFF));
+
+ if (rc)
+ return -EIO;
+
+ skb_trim(skb, skb->len - 2);
+
+ return 0;
+}
+
static inline void digital_switch_rf(struct nfc_digital_dev *ddev, bool on)
{
ddev->ops->switch_rf(ddev, on);
return rc;
}
+int digital_target_found(struct nfc_digital_dev *ddev,
+ struct nfc_target *target, u8 protocol)
+{
+ int rc;
+ u8 framing;
+ u8 rf_tech;
+ int (*check_crc)(struct sk_buff *skb);
+ void (*add_crc)(struct sk_buff *skb);
+
+ rf_tech = ddev->poll_techs[ddev->poll_tech_index].rf_tech;
+
+ switch (protocol) {
+ case NFC_PROTO_JEWEL:
+ framing = NFC_DIGITAL_FRAMING_NFCA_T1T;
+ check_crc = digital_skb_check_crc_b;
+ add_crc = digital_skb_add_crc_b;
+ break;
+
+ case NFC_PROTO_MIFARE:
+ framing = NFC_DIGITAL_FRAMING_NFCA_T2T;
+ check_crc = digital_skb_check_crc_a;
+ add_crc = digital_skb_add_crc_a;
+ break;
+
+ default:
+ PR_ERR("Invalid protocol %d", protocol);
+ return -EINVAL;
+ }
+
+ PR_DBG("rf_tech=%d, protocol=%d", rf_tech, protocol);
+
+ ddev->curr_rf_tech = rf_tech;
+ ddev->curr_protocol = protocol;
+
+ if (DIGITAL_DRV_CAPS_IN_CRC(ddev)) {
+ ddev->skb_add_crc = digital_skb_add_crc_none;
+ ddev->skb_check_crc = digital_skb_check_crc_none;
+ } else {
+ ddev->skb_add_crc = add_crc;
+ ddev->skb_check_crc = check_crc;
+ }
+
+ rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING, framing);
+ if (rc)
+ return rc;
+
+ target->supported_protocols = (1 << protocol);
+ rc = nfc_targets_found(ddev->nfc_dev, target, 1);
+ if (rc)
+ return rc;
+
+ ddev->poll_tech_count = 0;
+
+ return 0;
+}
+
void digital_poll_next_tech(struct nfc_digital_dev *ddev)
{
digital_switch_rf(ddev, 0);
return -EOPNOTSUPP;
}
+static void digital_in_send_complete(struct nfc_digital_dev *ddev, void *arg,
+ struct sk_buff *resp)
+{
+ struct digital_data_exch *data_exch = arg;
+ int rc;
+
+ if (IS_ERR(resp)) {
+ rc = PTR_ERR(resp);
+ goto done;
+ }
+
+ if (ddev->curr_protocol == NFC_PROTO_MIFARE)
+ rc = digital_in_recv_mifare_res(resp);
+ else
+ rc = ddev->skb_check_crc(resp);
+
+ if (rc) {
+ kfree_skb(resp);
+ resp = NULL;
+ }
+
+done:
+ data_exch->cb(data_exch->cb_context, resp, rc);
+
+ kfree(data_exch);
+}
+
static int digital_in_send(struct nfc_dev *nfc_dev, struct nfc_target *target,
struct sk_buff *skb, data_exchange_cb_t cb,
void *cb_context)
{
- return -EOPNOTSUPP;
+ struct nfc_digital_dev *ddev = nfc_get_drvdata(nfc_dev);
+ struct digital_data_exch *data_exch;
+
+ data_exch = kzalloc(sizeof(struct digital_data_exch), GFP_KERNEL);
+ if (!data_exch) {
+ PR_ERR("Failed to allocate data_exch struct");
+ return -ENOMEM;
+ }
+
+ data_exch->cb = cb;
+ data_exch->cb_context = cb_context;
+
+ ddev->skb_add_crc(skb);
+
+ return digital_in_send_cmd(ddev, skb, 500, digital_in_send_complete,
+ data_exch);
}
static struct nfc_ops digital_nfc_ops = {
#define DIGITAL_SDD_RES_CT 0x88
#define DIGITAL_SDD_RES_LEN 5
+#define DIGITAL_SEL_RES_NFCID1_COMPLETE(sel_res) (!((sel_res) & 0x04))
+#define DIGITAL_SEL_RES_IS_T2T(sel_res) (!((sel_res) & 0x60))
+
+#define DIGITAL_SENS_RES_IS_T1T(sens_res) (((sens_res) & 0x000C) == 0x000C)
+#define DIGITAL_SENS_RES_IS_VALID(sens_res) \
+ ((!((sens_res) & 0x1F00) && (((sens_res) & 0x000C) == 0x000C)) || \
+ (((sens_res) & 0x1F00) && ((sens_res) & 0x000C) != 0x000C))
+
+#define DIGITAL_MIFARE_READ_RES_LEN 16
+#define DIGITAL_MIFARE_ACK_RES 0x0A
+
+struct digital_sdd_res {
+ u8 nfcid1[4];
+ u8 bcc;
+} __packed;
+
+struct digital_sel_req {
+ u8 sel_cmd;
+ u8 b2;
+ u8 nfcid1[4];
+ u8 bcc;
+} __packed;
+
+static int digital_in_send_sdd_req(struct nfc_digital_dev *ddev,
+ struct nfc_target *target);
+
+static void digital_in_recv_sel_res(struct nfc_digital_dev *ddev, void *arg,
+ struct sk_buff *resp)
+{
+ struct nfc_target *target = arg;
+ int rc;
+ u8 sel_res;
+ u8 nfc_proto;
+
+ if (IS_ERR(resp)) {
+ rc = PTR_ERR(resp);
+ resp = NULL;
+ goto exit;
+ }
+
+ if (!DIGITAL_DRV_CAPS_IN_CRC(ddev)) {
+ rc = digital_skb_check_crc_a(resp);
+ if (rc) {
+ PROTOCOL_ERR("4.4.1.3");
+ goto exit;
+ }
+ }
+
+ if (!resp->len) {
+ rc = -EIO;
+ goto exit;
+ }
+
+ sel_res = resp->data[0];
+
+ if (!DIGITAL_SEL_RES_NFCID1_COMPLETE(sel_res)) {
+ rc = digital_in_send_sdd_req(ddev, target);
+ if (rc)
+ goto exit;
+
+ goto exit_free_skb;
+ }
+
+ if (DIGITAL_SEL_RES_IS_T2T(sel_res)) {
+ nfc_proto = NFC_PROTO_MIFARE;
+ } else {
+ rc = -EOPNOTSUPP;
+ goto exit;
+ }
+
+ target->sel_res = sel_res;
+
+ rc = digital_target_found(ddev, target, nfc_proto);
+
+exit:
+ kfree(target);
+
+exit_free_skb:
+ dev_kfree_skb(resp);
+
+ if (rc)
+ digital_poll_next_tech(ddev);
+}
+
+static int digital_in_send_sel_req(struct nfc_digital_dev *ddev,
+ struct nfc_target *target,
+ struct digital_sdd_res *sdd_res)
+{
+ struct sk_buff *skb;
+ struct digital_sel_req *sel_req;
+ u8 sel_cmd;
+ int rc;
+
+ skb = digital_skb_alloc(ddev, sizeof(struct digital_sel_req));
+ if (!skb)
+ return -ENOMEM;
+
+ skb_put(skb, sizeof(struct digital_sel_req));
+ sel_req = (struct digital_sel_req *)skb->data;
+
+ if (target->nfcid1_len <= 4)
+ sel_cmd = DIGITAL_CMD_SEL_REQ_CL1;
+ else if (target->nfcid1_len < 10)
+ sel_cmd = DIGITAL_CMD_SEL_REQ_CL2;
+ else
+ sel_cmd = DIGITAL_CMD_SEL_REQ_CL3;
+
+ sel_req->sel_cmd = sel_cmd;
+ sel_req->b2 = 0x70;
+ memcpy(sel_req->nfcid1, sdd_res->nfcid1, 4);
+ sel_req->bcc = sdd_res->bcc;
+
+ if (DIGITAL_DRV_CAPS_IN_CRC(ddev)) {
+ rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
+ NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A);
+ if (rc)
+ goto exit;
+ } else {
+ digital_skb_add_crc_a(skb);
+ }
+
+ rc = digital_in_send_cmd(ddev, skb, 30, digital_in_recv_sel_res,
+ target);
+exit:
+ if (rc)
+ kfree_skb(skb);
+
+ return rc;
+}
+
+static void digital_in_recv_sdd_res(struct nfc_digital_dev *ddev, void *arg,
+ struct sk_buff *resp)
+{
+ struct nfc_target *target = arg;
+ struct digital_sdd_res *sdd_res;
+ int rc;
+ u8 offset, size;
+ u8 i, bcc;
+
+ if (IS_ERR(resp)) {
+ rc = PTR_ERR(resp);
+ resp = NULL;
+ goto exit;
+ }
+
+ if (resp->len < DIGITAL_SDD_RES_LEN) {
+ PROTOCOL_ERR("4.7.2.8");
+ rc = -EINVAL;
+ goto exit;
+ }
+
+ sdd_res = (struct digital_sdd_res *)resp->data;
+
+ for (i = 0, bcc = 0; i < 4; i++)
+ bcc ^= sdd_res->nfcid1[i];
+
+ if (bcc != sdd_res->bcc) {
+ PROTOCOL_ERR("4.7.2.6");
+ rc = -EINVAL;
+ goto exit;
+ }
+
+ if (sdd_res->nfcid1[0] == DIGITAL_SDD_RES_CT) {
+ offset = 1;
+ size = 3;
+ } else {
+ offset = 0;
+ size = 4;
+ }
+
+ memcpy(target->nfcid1 + target->nfcid1_len, sdd_res->nfcid1 + offset,
+ size);
+ target->nfcid1_len += size;
+
+ rc = digital_in_send_sel_req(ddev, target, sdd_res);
+
+exit:
+ dev_kfree_skb(resp);
+
+ if (rc) {
+ kfree(target);
+ digital_poll_next_tech(ddev);
+ }
+}
+
+static int digital_in_send_sdd_req(struct nfc_digital_dev *ddev,
+ struct nfc_target *target)
+{
+ int rc;
+ struct sk_buff *skb;
+ u8 sel_cmd;
+
+ rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
+ NFC_DIGITAL_FRAMING_NFCA_STANDARD);
+ if (rc)
+ return rc;
+
+ skb = digital_skb_alloc(ddev, 2);
+ if (!skb) {
+ PR_ERR("alloc_skb failed");
+ return -ENOMEM;
+ }
+
+ if (target->nfcid1_len == 0)
+ sel_cmd = DIGITAL_CMD_SEL_REQ_CL1;
+ else if (target->nfcid1_len == 3)
+ sel_cmd = DIGITAL_CMD_SEL_REQ_CL2;
+ else
+ sel_cmd = DIGITAL_CMD_SEL_REQ_CL3;
+
+ *skb_put(skb, sizeof(u8)) = sel_cmd;
+ *skb_put(skb, sizeof(u8)) = DIGITAL_SDD_REQ_SEL_PAR;
+
+ return digital_in_send_cmd(ddev, skb, 30, digital_in_recv_sdd_res,
+ target);
+}
+
static void digital_in_recv_sens_res(struct nfc_digital_dev *ddev, void *arg,
struct sk_buff *resp)
{
- if (!IS_ERR(resp))
- dev_kfree_skb(resp);
+ struct nfc_target *target = NULL;
+ u16 sens_res;
+ int rc;
+
+ if (IS_ERR(resp)) {
+ rc = PTR_ERR(resp);
+ resp = NULL;
+ goto exit;
+ }
+
+ if (resp->len < sizeof(u16)) {
+ rc = -EIO;
+ goto exit;
+ }
+
+ target = kzalloc(sizeof(struct nfc_target), GFP_KERNEL);
+ if (!target) {
+ rc = -ENOMEM;
+ goto exit;
+ }
+
+ memcpy(&target->sens_res, resp->data, sizeof(u16));
- digital_poll_next_tech(ddev);
+ sens_res = be16_to_cpu(target->sens_res);
+
+ if (!DIGITAL_SENS_RES_IS_VALID(sens_res)) {
+ PROTOCOL_ERR("4.6.3.3");
+ rc = -EINVAL;
+ goto exit;
+ }
+
+ if (DIGITAL_SENS_RES_IS_T1T(sens_res))
+ rc = digital_target_found(ddev, target, NFC_PROTO_JEWEL);
+ else
+ rc = digital_in_send_sdd_req(ddev, target);
+
+exit:
+ dev_kfree_skb(resp);
+
+ if (rc) {
+ kfree(target);
+ digital_poll_next_tech(ddev);
+ }
}
int digital_in_send_sens_req(struct nfc_digital_dev *ddev, u8 rf_tech)
return rc;
}
+
+int digital_in_recv_mifare_res(struct sk_buff *resp)
+{
+ /* Successful READ command response is 16 data bytes + 2 CRC bytes long.
+ * Since the driver can't differentiate a ACK/NACK response from a valid
+ * READ response, the CRC calculation must be handled at digital level
+ * even if the driver supports it for this technology.
+ */
+ if (resp->len == DIGITAL_MIFARE_READ_RES_LEN + DIGITAL_CRC_LEN) {
+ if (digital_skb_check_crc_a(resp)) {
+ PROTOCOL_ERR("9.4.1.2");
+ return -EIO;
+ }
+
+ return 0;
+ }
+
+ /* ACK response (i.e. successful WRITE). */
+ if (resp->len == 1 && resp->data[0] == DIGITAL_MIFARE_ACK_RES) {
+ resp->data[0] = 0;
+ return 0;
+ }
+
+ /* NACK and any other responses are treated as error. */
+ return -EIO;
+}
projects / karo-tx-linux.git / commitdiff