--- /dev/null
+/*
+ * --------------------------------------------------------------------
+ * Driver for ST NFC Transceiver ST95HF
+ * --------------------------------------------------------------------
+ * Copyright (C) 2015 STMicroelectronics Pvt. Ltd. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/err.h>
+#include <linux/gpio.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/nfc.h>
+#include <linux/of_gpio.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/property.h>
+#include <linux/regulator/consumer.h>
+#include <linux/wait.h>
+#include <net/nfc/digital.h>
+#include <net/nfc/nfc.h>
+
+#include "spi.h"
+
+/* supported protocols */
+#define ST95HF_SUPPORTED_PROT (NFC_PROTO_ISO14443_MASK | \
+ NFC_PROTO_ISO14443_B_MASK | \
+ NFC_PROTO_ISO15693_MASK)
+/* driver capabilities */
+#define ST95HF_CAPABILITIES NFC_DIGITAL_DRV_CAPS_IN_CRC
+
+/* Command Send Interface */
+/* ST95HF_COMMAND_SEND CMD Ids */
+#define ECHO_CMD 0x55
+#define WRITE_REGISTER_CMD 0x9
+#define PROTOCOL_SELECT_CMD 0x2
+#define SEND_RECEIVE_CMD 0x4
+
+/* Select protocol codes */
+#define ISO15693_PROTOCOL_CODE 0x1
+#define ISO14443A_PROTOCOL_CODE 0x2
+#define ISO14443B_PROTOCOL_CODE 0x3
+
+/*
+ * head room len is 3
+ * 1 byte for control byte
+ * 1 byte for cmd
+ * 1 byte for size
+ */
+#define ST95HF_HEADROOM_LEN 3
+
+/*
+ * tailroom is 1 for ISO14443A
+ * and 0 for ISO14443B/ISO15693,
+ * hence the max value 1 should be
+ * taken.
+ */
+#define ST95HF_TAILROOM_LEN 1
+
+/* Command Response interface */
+#define MAX_RESPONSE_BUFFER_SIZE 280
+#define ECHORESPONSE 0x55
+#define ST95HF_ERR_MASK 0xF
+#define ST95HF_TIMEOUT_ERROR 0x87
+#define ST95HF_NFCA_CRC_ERR_MASK 0x20
+#define ST95HF_NFCB_CRC_ERR_MASK 0x01
+
+/* ST95HF transmission flag values */
+#define TRFLAG_NFCA_SHORT_FRAME 0x07
+#define TRFLAG_NFCA_STD_FRAME 0x08
+#define TRFLAG_NFCA_STD_FRAME_CRC 0x28
+
+/* Misc defs */
+#define HIGH 1
+#define LOW 0
+#define ISO14443A_RATS_REQ 0xE0
+#define RATS_TB1_PRESENT_MASK 0x20
+#define RATS_TA1_PRESENT_MASK 0x10
+#define TB1_FWI_MASK 0xF0
+#define WTX_REQ_FROM_TAG 0xF2
+
+#define MAX_CMD_LEN 0x7
+
+#define MAX_CMD_PARAMS 4
+struct cmd {
+ int cmd_len;
+ unsigned char cmd_id;
+ unsigned char no_cmd_params;
+ unsigned char cmd_params[MAX_CMD_PARAMS];
+ enum req_type req;
+};
+
+struct param_list {
+ int param_offset;
+ int new_param_val;
+};
+
+/*
+ * List of top-level cmds to be used internally by the driver.
+ * All these commands are build on top of ST95HF basic commands
+ * such as SEND_RECEIVE_CMD, PROTOCOL_SELECT_CMD, etc.
+ * These top level cmds are used internally while implementing various ops of
+ * digital layer/driver probe or extending the digital framework layer for
+ * features that are not yet implemented there, for example, WTX cmd handling.
+ */
+enum st95hf_cmd_list {
+ CMD_ECHO,
+ CMD_ISO14443A_CONFIG,
+ CMD_ISO14443A_DEMOGAIN,
+ CMD_ISO14443B_DEMOGAIN,
+ CMD_ISO14443A_PROTOCOL_SELECT,
+ CMD_ISO14443B_PROTOCOL_SELECT,
+ CMD_WTX_RESPONSE,
+ CMD_FIELD_OFF,
+ CMD_ISO15693_PROTOCOL_SELECT,
+};
+
+static const struct cmd cmd_array[] = {
+ [CMD_ECHO] = {
+ .cmd_len = 0x2,
+ .cmd_id = ECHO_CMD,
+ .no_cmd_params = 0,
+ .req = SYNC,
+ },
+ [CMD_ISO14443A_CONFIG] = {
+ .cmd_len = 0x7,
+ .cmd_id = WRITE_REGISTER_CMD,
+ .no_cmd_params = 0x4,
+ .cmd_params = {0x3A, 0x00, 0x5A, 0x04},
+ .req = SYNC,
+ },
+ [CMD_ISO14443A_DEMOGAIN] = {
+ .cmd_len = 0x7,
+ .cmd_id = WRITE_REGISTER_CMD,
+ .no_cmd_params = 0x4,
+ .cmd_params = {0x68, 0x01, 0x01, 0xDF},
+ .req = SYNC,
+ },
+ [CMD_ISO14443B_DEMOGAIN] = {
+ .cmd_len = 0x7,
+ .cmd_id = WRITE_REGISTER_CMD,
+ .no_cmd_params = 0x4,
+ .cmd_params = {0x68, 0x01, 0x01, 0x51},
+ .req = SYNC,
+ },
+ [CMD_ISO14443A_PROTOCOL_SELECT] = {
+ .cmd_len = 0x7,
+ .cmd_id = PROTOCOL_SELECT_CMD,
+ .no_cmd_params = 0x4,
+ .cmd_params = {ISO14443A_PROTOCOL_CODE, 0x00, 0x01, 0xA0},
+ .req = SYNC,
+ },
+ [CMD_ISO14443B_PROTOCOL_SELECT] = {
+ .cmd_len = 0x7,
+ .cmd_id = PROTOCOL_SELECT_CMD,
+ .no_cmd_params = 0x4,
+ .cmd_params = {ISO14443B_PROTOCOL_CODE, 0x01, 0x03, 0xFF},
+ .req = SYNC,
+ },
+ [CMD_WTX_RESPONSE] = {
+ .cmd_len = 0x6,
+ .cmd_id = SEND_RECEIVE_CMD,
+ .no_cmd_params = 0x3,
+ .cmd_params = {0xF2, 0x00, TRFLAG_NFCA_STD_FRAME_CRC},
+ .req = ASYNC,
+ },
+ [CMD_FIELD_OFF] = {
+ .cmd_len = 0x5,
+ .cmd_id = PROTOCOL_SELECT_CMD,
+ .no_cmd_params = 0x2,
+ .cmd_params = {0x0, 0x0},
+ .req = SYNC,
+ },
+ [CMD_ISO15693_PROTOCOL_SELECT] = {
+ .cmd_len = 0x5,
+ .cmd_id = PROTOCOL_SELECT_CMD,
+ .no_cmd_params = 0x2,
+ .cmd_params = {ISO15693_PROTOCOL_CODE, 0x0D},
+ .req = SYNC,
+ },
+};
+
+/* st95_digital_cmd_complete_arg stores client context */
+struct st95_digital_cmd_complete_arg {
+ struct sk_buff *skb_resp;
+ nfc_digital_cmd_complete_t complete_cb;
+ void *cb_usrarg;
+ bool rats;
+};
+
+/*
+ * structure containing ST95HF driver specific data.
+ * @spicontext: structure containing information required
+ * for spi communication between st95hf and host.
+ * @ddev: nfc digital device object.
+ * @nfcdev: nfc device object.
+ * @enable_gpio: gpio used to enable st95hf transceiver.
+ * @complete_cb_arg: structure to store various context information
+ * that is passed from nfc requesting thread to the threaded ISR.
+ * @st95hf_supply: regulator "consumer" for NFC device.
+ * @sendrcv_trflag: last byte of frame send by sendrecv command
+ * of st95hf. This byte contains transmission flag info.
+ * @exchange_lock: semaphore used for signaling the st95hf_remove
+ * function that the last outstanding async nfc request is finished.
+ * @rm_lock: mutex for ensuring safe access of nfc digital object
+ * from threaded ISR. Usage of this mutex avoids any race between
+ * deletion of the object from st95hf_remove() and its access from
+ * the threaded ISR.
+ * @nfcdev_free: flag to have the state of nfc device object.
+ * [alive | died]
+ * @current_protocol: current nfc protocol.
+ * @current_rf_tech: current rf technology.
+ * @fwi: frame waiting index, received in reply of RATS according to
+ * digital protocol.
+ */
+struct st95hf_context {
+ struct st95hf_spi_context spicontext;
+ struct nfc_digital_dev *ddev;
+ struct nfc_dev *nfcdev;
+ unsigned int enable_gpio;
+ struct st95_digital_cmd_complete_arg complete_cb_arg;
+ struct regulator *st95hf_supply;
+ unsigned char sendrcv_trflag;
+ struct semaphore exchange_lock;
+ struct mutex rm_lock;
+ bool nfcdev_free;
+ u8 current_protocol;
+ u8 current_rf_tech;
+ int fwi;
+};
+
+/*
+ * st95hf_send_recv_cmd() is for sending commands to ST95HF
+ * that are described in the cmd_array[]. It can optionally
+ * receive the response if the cmd request is of type
+ * SYNC. For that to happen caller must pass true to recv_res.
+ * For ASYNC request, recv_res is ignored and the
+ * function will never try to receive the response on behalf
+ * of the caller.
+ */
+static int st95hf_send_recv_cmd(struct st95hf_context *st95context,
+ enum st95hf_cmd_list cmd,
+ int no_modif,
+ struct param_list *list_array,
+ bool recv_res)
+{
+ unsigned char spi_cmd_buffer[MAX_CMD_LEN];
+ int i, ret;
+ struct device *dev = &st95context->spicontext.spidev->dev;
+
+ if (cmd_array[cmd].cmd_len > MAX_CMD_LEN)
+ return -EINVAL;
+ if (cmd_array[cmd].no_cmd_params < no_modif)
+ return -EINVAL;
+ if (no_modif && !list_array)
+ return -EINVAL;
+
+ spi_cmd_buffer[0] = ST95HF_COMMAND_SEND;
+ spi_cmd_buffer[1] = cmd_array[cmd].cmd_id;
+ spi_cmd_buffer[2] = cmd_array[cmd].no_cmd_params;
+
+ memcpy(&spi_cmd_buffer[3], cmd_array[cmd].cmd_params,
+ spi_cmd_buffer[2]);
+
+ for (i = 0; i < no_modif; i++) {
+ if (list_array[i].param_offset >= cmd_array[cmd].no_cmd_params)
+ return -EINVAL;
+ spi_cmd_buffer[3 + list_array[i].param_offset] =
+ list_array[i].new_param_val;
+ }
+
+ ret = st95hf_spi_send(&st95context->spicontext,
+ spi_cmd_buffer,
+ cmd_array[cmd].cmd_len,
+ cmd_array[cmd].req);
+ if (ret) {
+ dev_err(dev, "st95hf_spi_send failed with error %d\n", ret);
+ return ret;
+ }
+
+ if (cmd_array[cmd].req == SYNC && recv_res) {
+ unsigned char st95hf_response_arr[2];
+
+ ret = st95hf_spi_recv_response(&st95context->spicontext,
+ st95hf_response_arr);
+ if (ret < 0) {
+ dev_err(dev, "spi error from st95hf_spi_recv_response(), err = 0x%x\n",
+ ret);
+ return ret;
+ }
+
+ if (st95hf_response_arr[0]) {
+ dev_err(dev, "st95hf error from st95hf_spi_recv_response(), err = 0x%x\n",
+ st95hf_response_arr[0]);
+ return -EIO;
+ }
+ }
+
+ return 0;
+}
+
+static int st95hf_echo_command(struct st95hf_context *st95context)
+{
+ int result = 0;
+ unsigned char echo_response;
+
+ result = st95hf_send_recv_cmd(st95context, CMD_ECHO, 0, NULL, false);
+ if (result)
+ return result;
+
+ /* If control reached here, response can be taken */
+ result = st95hf_spi_recv_echo_res(&st95context->spicontext,
+ &echo_response);
+ if (result) {
+ dev_err(&st95context->spicontext.spidev->dev,
+ "err: echo response receieve error = 0x%x\n", result);
+ return result;
+ }
+
+ if (echo_response == ECHORESPONSE)
+ return 0;
+
+ dev_err(&st95context->spicontext.spidev->dev, "err: echo res is 0x%x\n",
+ echo_response);
+
+ return -EIO;
+}
+
+static int secondary_configuration_type4a(struct st95hf_context *stcontext)
+{
+ int result = 0;
+ struct device *dev = &stcontext->nfcdev->dev;
+
+ /* 14443A config setting after select protocol */
+ result = st95hf_send_recv_cmd(stcontext,
+ CMD_ISO14443A_CONFIG,
+ 0,
+ NULL,
+ true);
+ if (result) {
+ dev_err(dev, "type a config cmd, err = 0x%x\n", result);
+ return result;
+ }
+
+ /* 14443A demo gain setting */
+ result = st95hf_send_recv_cmd(stcontext,
+ CMD_ISO14443A_DEMOGAIN,
+ 0,
+ NULL,
+ true);
+ if (result)
+ dev_err(dev, "type a demogain cmd, err = 0x%x\n", result);
+
+ return result;
+}
+
+static int secondary_configuration_type4b(struct st95hf_context *stcontext)
+{
+ int result = 0;
+ struct device *dev = &stcontext->nfcdev->dev;
+
+ result = st95hf_send_recv_cmd(stcontext,
+ CMD_ISO14443B_DEMOGAIN,
+ 0,
+ NULL,
+ true);
+ if (result)
+ dev_err(dev, "type b demogain cmd, err = 0x%x\n", result);
+
+ return result;
+}
+
+static int st95hf_select_protocol(struct st95hf_context *stcontext, int type)
+{
+ int result = 0;
+ struct device *dev;
+
+ dev = &stcontext->nfcdev->dev;
+
+ switch (type) {
+ case NFC_DIGITAL_RF_TECH_106A:
+ stcontext->current_rf_tech = NFC_DIGITAL_RF_TECH_106A;
+ result = st95hf_send_recv_cmd(stcontext,
+ CMD_ISO14443A_PROTOCOL_SELECT,
+ 0,
+ NULL,
+ true);
+ if (result) {
+ dev_err(dev, "protocol sel, err = 0x%x\n",
+ result);
+ return result;
+ }
+
+ /* secondary config. for 14443Type 4A after protocol select */
+ result = secondary_configuration_type4a(stcontext);
+ if (result) {
+ dev_err(dev, "type a secondary config, err = 0x%x\n",
+ result);
+ return result;
+ }
+ break;
+ case NFC_DIGITAL_RF_TECH_106B:
+ stcontext->current_rf_tech = NFC_DIGITAL_RF_TECH_106B;
+ result = st95hf_send_recv_cmd(stcontext,
+ CMD_ISO14443B_PROTOCOL_SELECT,
+ 0,
+ NULL,
+ true);
+ if (result) {
+ dev_err(dev, "protocol sel send, err = 0x%x\n",
+ result);
+ return result;
+ }
+
+ /*
+ * delay of 5-6 ms is required after select protocol
+ * command in case of ISO14443 Type B
+ */
+ usleep_range(50000, 60000);
+
+ /* secondary config. for 14443Type 4B after protocol select */
+ result = secondary_configuration_type4b(stcontext);
+ if (result) {
+ dev_err(dev, "type b secondary config, err = 0x%x\n",
+ result);
+ return result;
+ }
+ break;
+ case NFC_DIGITAL_RF_TECH_ISO15693:
+ stcontext->current_rf_tech = NFC_DIGITAL_RF_TECH_ISO15693;
+ result = st95hf_send_recv_cmd(stcontext,
+ CMD_ISO15693_PROTOCOL_SELECT,
+ 0,
+ NULL,
+ true);
+ if (result) {
+ dev_err(dev, "protocol sel send, err = 0x%x\n",
+ result);
+ return result;
+ }
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static void st95hf_send_st95enable_negativepulse(struct st95hf_context *st95con)
+{
+ /* First make irq_in pin high */
+ gpio_set_value(st95con->enable_gpio, HIGH);
+
+ /* wait for 1 milisecond */
+ usleep_range(1000, 2000);
+
+ /* Make irq_in pin low */
+ gpio_set_value(st95con->enable_gpio, LOW);
+
+ /* wait for minimum interrupt pulse to make st95 active */
+ usleep_range(1000, 2000);
+
+ /* At end make it high */
+ gpio_set_value(st95con->enable_gpio, HIGH);
+}
+
+/*
+ * Send a reset sequence over SPI bus (Reset command + wait 3ms +
+ * negative pulse on st95hf enable gpio
+ */
+static int st95hf_send_spi_reset_sequence(struct st95hf_context *st95context)
+{
+ int result = 0;
+ unsigned char reset_cmd = ST95HF_COMMAND_RESET;
+
+ result = st95hf_spi_send(&st95context->spicontext,
+ &reset_cmd,
+ ST95HF_RESET_CMD_LEN,
+ ASYNC);
+ if (result) {
+ dev_err(&st95context->spicontext.spidev->dev,
+ "spi reset sequence cmd error = %d", result);
+ return result;
+ }
+
+ /* wait for 3 milisecond to complete the controller reset process */
+ usleep_range(3000, 4000);
+
+ /* send negative pulse to make st95hf active */
+ st95hf_send_st95enable_negativepulse(st95context);
+
+ /* wait for 10 milisecond : HFO setup time */
+ usleep_range(10000, 20000);
+
+ return result;
+}
+
+static int st95hf_por_sequence(struct st95hf_context *st95context)
+{
+ int nth_attempt = 1;
+ int result;
+
+ st95hf_send_st95enable_negativepulse(st95context);
+
+ usleep_range(5000, 6000);
+ do {
+ /* send an ECHO command and checks ST95HF response */
+ result = st95hf_echo_command(st95context);
+
+ dev_dbg(&st95context->spicontext.spidev->dev,
+ "response from echo function = 0x%x, attempt = %d\n",
+ result, nth_attempt);
+
+ if (!result)
+ return 0;
+
+ /* send an pulse on IRQ in case of the chip is on sleep state */
+ if (nth_attempt == 2)
+ st95hf_send_st95enable_negativepulse(st95context);
+ else
+ st95hf_send_spi_reset_sequence(st95context);
+
+ /* delay of 50 milisecond */
+ usleep_range(50000, 51000);
+ } while (nth_attempt++ < 3);
+
+ return -ETIMEDOUT;
+}
+
+static int iso14443_config_fdt(struct st95hf_context *st95context, int wtxm)
+{
+ int result = 0;
+ struct device *dev = &st95context->spicontext.spidev->dev;
+ struct nfc_digital_dev *nfcddev = st95context->ddev;
+ unsigned char pp_typeb;
+ struct param_list new_params[2];
+
+ pp_typeb = cmd_array[CMD_ISO14443B_PROTOCOL_SELECT].cmd_params[2];
+
+ if (nfcddev->curr_protocol == NFC_PROTO_ISO14443 &&
+ st95context->fwi < 4)
+ st95context->fwi = 4;
+
+ new_params[0].param_offset = 2;
+ if (nfcddev->curr_protocol == NFC_PROTO_ISO14443)
+ new_params[0].new_param_val = st95context->fwi;
+ else if (nfcddev->curr_protocol == NFC_PROTO_ISO14443_B)
+ new_params[0].new_param_val = pp_typeb;
+
+ new_params[1].param_offset = 3;
+ new_params[1].new_param_val = wtxm;
+
+ switch (nfcddev->curr_protocol) {
+ case NFC_PROTO_ISO14443:
+ result = st95hf_send_recv_cmd(st95context,
+ CMD_ISO14443A_PROTOCOL_SELECT,
+ 2,
+ new_params,
+ true);
+ if (result) {
+ dev_err(dev, "WTX type a sel proto, err = 0x%x\n",
+ result);
+ return result;
+ }
+
+ /* secondary config. for 14443Type 4A after protocol select */
+ result = secondary_configuration_type4a(st95context);
+ if (result) {
+ dev_err(dev, "WTX type a second. config, err = 0x%x\n",
+ result);
+ return result;
+ }
+ break;
+ case NFC_PROTO_ISO14443_B:
+ result = st95hf_send_recv_cmd(st95context,
+ CMD_ISO14443B_PROTOCOL_SELECT,
+ 2,
+ new_params,
+ true);
+ if (result) {
+ dev_err(dev, "WTX type b sel proto, err = 0x%x\n",
+ result);
+ return result;
+ }
+
+ /* secondary config. for 14443Type 4B after protocol select */
+ result = secondary_configuration_type4b(st95context);
+ if (result) {
+ dev_err(dev, "WTX type b second. config, err = 0x%x\n",
+ result);
+ return result;
+ }
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int st95hf_handle_wtx(struct st95hf_context *stcontext,
+ bool new_wtx,
+ int wtx_val)
+{
+ int result = 0;
+ unsigned char val_mm = 0;
+ struct param_list new_params[1];
+ struct nfc_digital_dev *nfcddev = stcontext->ddev;
+ struct device *dev = &stcontext->nfcdev->dev;
+
+ if (new_wtx) {
+ result = iso14443_config_fdt(stcontext, wtx_val & 0x3f);
+ if (result) {
+ dev_err(dev, "Config. setting error on WTX req, err = 0x%x\n",
+ result);
+ return result;
+ }
+
+ /* Send response of wtx with ASYNC as no response expected */
+ new_params[0].param_offset = 1;
+ new_params[0].new_param_val = wtx_val;
+
+ result = st95hf_send_recv_cmd(stcontext,
+ CMD_WTX_RESPONSE,
+ 1,
+ new_params,
+ false);
+ if (result)
+ dev_err(dev, "WTX response send, err = 0x%x\n", result);
+ return result;
+ }
+
+ /* if no new wtx, cofigure with default values */
+ if (nfcddev->curr_protocol == NFC_PROTO_ISO14443)
+ val_mm = cmd_array[CMD_ISO14443A_PROTOCOL_SELECT].cmd_params[3];
+ else if (nfcddev->curr_protocol == NFC_PROTO_ISO14443_B)
+ val_mm = cmd_array[CMD_ISO14443B_PROTOCOL_SELECT].cmd_params[3];
+
+ result = iso14443_config_fdt(stcontext, val_mm);
+ if (result)
+ dev_err(dev, "Default config. setting error after WTX processing, err = 0x%x\n",
+ result);
+
+ return result;
+}
+
+static int st95hf_error_handling(struct st95hf_context *stcontext,
+ struct sk_buff *skb_resp,
+ int res_len)
+{
+ int result = 0;
+ unsigned char error_byte;
+ struct device *dev = &stcontext->nfcdev->dev;
+
+ /* First check ST95HF specific error */
+ if (skb_resp->data[0] & ST95HF_ERR_MASK) {
+ if (skb_resp->data[0] == ST95HF_TIMEOUT_ERROR)
+ result = -ETIMEDOUT;
+ else
+ result = -EIO;
+ return result;
+ }
+
+ /* Check for CRC err only if CRC is present in the tag response */
+ switch (stcontext->current_rf_tech) {
+ case NFC_DIGITAL_RF_TECH_106A:
+ if (stcontext->sendrcv_trflag == TRFLAG_NFCA_STD_FRAME_CRC) {
+ error_byte = skb_resp->data[res_len - 3];
+ if (error_byte & ST95HF_NFCA_CRC_ERR_MASK) {
+ /* CRC error occurred */
+ dev_err(dev, "CRC error, byte received = 0x%x\n",
+ error_byte);
+ result = -EIO;
+ }
+ }
+ break;
+ case NFC_DIGITAL_RF_TECH_106B:
+ case NFC_DIGITAL_RF_TECH_ISO15693:
+ error_byte = skb_resp->data[res_len - 1];
+ if (error_byte & ST95HF_NFCB_CRC_ERR_MASK) {
+ /* CRC error occurred */
+ dev_err(dev, "CRC error, byte received = 0x%x\n",
+ error_byte);
+ result = -EIO;
+ }
+ break;
+ }
+
+ return result;
+}
+
+static int st95hf_response_handler(struct st95hf_context *stcontext,
+ struct sk_buff *skb_resp,
+ int res_len)
+{
+ int result = 0;
+ int skb_len;
+ unsigned char val_mm;
+ struct nfc_digital_dev *nfcddev = stcontext->ddev;
+ struct device *dev = &stcontext->nfcdev->dev;
+ struct st95_digital_cmd_complete_arg *cb_arg;
+
+ cb_arg = &stcontext->complete_cb_arg;
+
+ /* Process the response */
+ skb_put(skb_resp, res_len);
+
+ /* Remove st95 header */
+ skb_pull(skb_resp, 2);
+
+ skb_len = skb_resp->len;
+
+ /* check if it is case of RATS request reply & FWI is present */
+ if (nfcddev->curr_protocol == NFC_PROTO_ISO14443 && cb_arg->rats &&
+ (skb_resp->data[1] & RATS_TB1_PRESENT_MASK)) {
+ if (skb_resp->data[1] & RATS_TA1_PRESENT_MASK)
+ stcontext->fwi =
+ (skb_resp->data[3] & TB1_FWI_MASK) >> 4;
+ else
+ stcontext->fwi =
+ (skb_resp->data[2] & TB1_FWI_MASK) >> 4;
+
+ val_mm = cmd_array[CMD_ISO14443A_PROTOCOL_SELECT].cmd_params[3];
+
+ result = iso14443_config_fdt(stcontext, val_mm);
+ if (result) {
+ dev_err(dev, "error in config_fdt to handle fwi of ATS, error=%d\n",
+ result);
+ return result;
+ }
+ }
+ cb_arg->rats = false;
+
+ /* Remove CRC bytes only if received frames data has an eod (CRC) */
+ switch (stcontext->current_rf_tech) {
+ case NFC_DIGITAL_RF_TECH_106A:
+ if (stcontext->sendrcv_trflag == TRFLAG_NFCA_STD_FRAME_CRC)
+ skb_trim(skb_resp, (skb_len - 5));
+ else
+ skb_trim(skb_resp, (skb_len - 3));
+ break;
+ case NFC_DIGITAL_RF_TECH_106B:
+ case NFC_DIGITAL_RF_TECH_ISO15693:
+ skb_trim(skb_resp, (skb_len - 3));
+ break;
+ }
+
+ return result;
+}
+
+static irqreturn_t irq_handler(int irq, void *st95hfcontext)
+{
+ struct st95hf_context *stcontext =
+ (struct st95hf_context *)st95hfcontext;
+
+ if (stcontext->spicontext.req_issync) {
+ complete(&stcontext->spicontext.done);
+ stcontext->spicontext.req_issync = false;
+ return IRQ_HANDLED;
+ }
+
+ return IRQ_WAKE_THREAD;
+}
+
+static irqreturn_t irq_thread_handler(int irq, void *st95hfcontext)
+{
+ int result = 0;
+ int res_len;
+ static bool wtx;
+ struct device *dev;
+ struct device *spidevice;
+ struct nfc_digital_dev *nfcddev;
+ struct sk_buff *skb_resp;
+ struct st95hf_context *stcontext =
+ (struct st95hf_context *)st95hfcontext;
+ struct st95_digital_cmd_complete_arg *cb_arg;
+
+ spidevice = &stcontext->spicontext.spidev->dev;
+
+ /*
+ * check semaphore, if not down() already, then we don't
+ * know in which context the ISR is called and surely it
+ * will be a bug. Note that down() of the semaphore is done
+ * in the corresponding st95hf_in_send_cmd() and then
+ * only this ISR should be called. ISR will up() the
+ * semaphore before leaving. Hence when the ISR is called
+ * the correct behaviour is down_trylock() should always
+ * return 1 (indicating semaphore cant be taken and hence no
+ * change in semaphore count).
+ * If not, then we up() the semaphore and crash on
+ * a BUG() !
+ */
+ if (!down_trylock(&stcontext->exchange_lock)) {
+ up(&stcontext->exchange_lock);
+ WARN(1, "unknown context in ST95HF ISR");
+ return IRQ_NONE;
+ }
+
+ cb_arg = &stcontext->complete_cb_arg;
+ skb_resp = cb_arg->skb_resp;
+
+ mutex_lock(&stcontext->rm_lock);
+ res_len = st95hf_spi_recv_response(&stcontext->spicontext,
+ skb_resp->data);
+ if (res_len < 0) {
+ dev_err(spidevice, "TISR spi response err = 0x%x\n", res_len);
+ result = res_len;
+ goto end;
+ }
+
+ /* if stcontext->nfcdev_free is true, it means remove already ran */
+ if (stcontext->nfcdev_free) {
+ result = -ENODEV;
+ goto end;
+ }
+
+ dev = &stcontext->nfcdev->dev;
+ nfcddev = stcontext->ddev;
+ if (skb_resp->data[2] == WTX_REQ_FROM_TAG) {
+ /* Request for new FWT from tag */
+ result = st95hf_handle_wtx(stcontext, true, skb_resp->data[3]);
+ if (result)
+ goto end;
+
+ wtx = true;
+ mutex_unlock(&stcontext->rm_lock);
+ return IRQ_HANDLED;
+ }
+
+ result = st95hf_error_handling(stcontext, skb_resp, res_len);
+ if (result)
+ goto end;
+
+ result = st95hf_response_handler(stcontext, skb_resp, res_len);
+ if (result)
+ goto end;
+
+ /*
+ * If select protocol is done on wtx req. do select protocol
+ * again with default values
+ */
+ if (wtx) {
+ wtx = false;
+ result = st95hf_handle_wtx(stcontext, false, 0);
+ if (result)
+ goto end;
+ }
+
+ /* call digital layer callback */
+ cb_arg->complete_cb(stcontext->ddev, cb_arg->cb_usrarg, skb_resp);
+
+ /* up the semaphore before returning */
+ up(&stcontext->exchange_lock);
+ mutex_unlock(&stcontext->rm_lock);
+
+ return IRQ_HANDLED;
+
+end:
+ kfree_skb(skb_resp);
+ wtx = false;
+ cb_arg->rats = false;
+ skb_resp = ERR_PTR(result);
+ /* call of callback with error */
+ cb_arg->complete_cb(stcontext->ddev, cb_arg->cb_usrarg, skb_resp);
+ /* up the semaphore before returning */
+ up(&stcontext->exchange_lock);
+ mutex_unlock(&stcontext->rm_lock);
+ return IRQ_HANDLED;
+}
+
+/* NFC ops functions definition */
+static int st95hf_in_configure_hw(struct nfc_digital_dev *ddev,
+ int type,
+ int param)
+{
+ struct st95hf_context *stcontext = nfc_digital_get_drvdata(ddev);
+
+ if (type == NFC_DIGITAL_CONFIG_RF_TECH)
+ return st95hf_select_protocol(stcontext, param);
+
+ if (type == NFC_DIGITAL_CONFIG_FRAMING) {
+ switch (param) {
+ case NFC_DIGITAL_FRAMING_NFCA_SHORT:
+ stcontext->sendrcv_trflag = TRFLAG_NFCA_SHORT_FRAME;
+ break;
+ case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
+ stcontext->sendrcv_trflag = TRFLAG_NFCA_STD_FRAME;
+ break;
+ case NFC_DIGITAL_FRAMING_NFCA_T4T:
+ case NFC_DIGITAL_FRAMING_NFCA_NFC_DEP:
+ case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
+ stcontext->sendrcv_trflag = TRFLAG_NFCA_STD_FRAME_CRC;
+ break;
+ case NFC_DIGITAL_FRAMING_NFCB:
+ case NFC_DIGITAL_FRAMING_ISO15693_INVENTORY:
+ case NFC_DIGITAL_FRAMING_ISO15693_T5T:
+ break;
+ }
+ }
+
+ return 0;
+}
+
+static int rf_off(struct st95hf_context *stcontext)
+{
+ int rc;
+ struct device *dev;
+
+ dev = &stcontext->nfcdev->dev;
+
+ rc = st95hf_send_recv_cmd(stcontext, CMD_FIELD_OFF, 0, NULL, true);
+ if (rc)
+ dev_err(dev, "protocol sel send field off, err = 0x%x\n", rc);
+
+ return rc;
+}
+
+static int st95hf_in_send_cmd(struct nfc_digital_dev *ddev,
+ struct sk_buff *skb,
+ u16 timeout,
+ nfc_digital_cmd_complete_t cb,
+ void *arg)
+{
+ struct st95hf_context *stcontext = nfc_digital_get_drvdata(ddev);
+ int rc;
+ struct sk_buff *skb_resp;
+ int len_data_to_tag = 0;
+
+ skb_resp = nfc_alloc_recv_skb(MAX_RESPONSE_BUFFER_SIZE, GFP_KERNEL);
+ if (!skb_resp) {
+ rc = -ENOMEM;
+ goto error;
+ }
+
+ switch (stcontext->current_rf_tech) {
+ case NFC_DIGITAL_RF_TECH_106A:
+ len_data_to_tag = skb->len + 1;
+ *skb_put(skb, 1) = stcontext->sendrcv_trflag;
+ break;
+ case NFC_DIGITAL_RF_TECH_106B:
+ case NFC_DIGITAL_RF_TECH_ISO15693:
+ len_data_to_tag = skb->len;
+ break;
+ default:
+ rc = -EINVAL;
+ goto free_skb_resp;
+ }
+
+ skb_push(skb, 3);
+ skb->data[0] = ST95HF_COMMAND_SEND;
+ skb->data[1] = SEND_RECEIVE_CMD;
+ skb->data[2] = len_data_to_tag;
+
+ stcontext->complete_cb_arg.skb_resp = skb_resp;
+ stcontext->complete_cb_arg.cb_usrarg = arg;
+ stcontext->complete_cb_arg.complete_cb = cb;
+
+ if ((skb->data[3] == ISO14443A_RATS_REQ) &&
+ ddev->curr_protocol == NFC_PROTO_ISO14443)
+ stcontext->complete_cb_arg.rats = true;
+
+ /*
+ * down the semaphore to indicate to remove func that an
+ * ISR is pending, note that it will not block here in any case.
+ * If found blocked, it is a BUG!
+ */
+ rc = down_killable(&stcontext->exchange_lock);
+ if (rc) {
+ WARN(1, "Semaphore is not found up in st95hf_in_send_cmd\n");
+ return rc;
+ }
+
+ rc = st95hf_spi_send(&stcontext->spicontext, skb->data,
+ skb->len,
+ ASYNC);
+ if (rc) {
+ dev_err(&stcontext->nfcdev->dev,
+ "Error %d trying to perform data_exchange", rc);
+ /* up the semaphore since ISR will never come in this case */
+ up(&stcontext->exchange_lock);
+ goto free_skb_resp;
+ }
+
+ kfree_skb(skb);
+
+ return rc;
+
+free_skb_resp:
+ kfree_skb(skb_resp);
+error:
+ return rc;
+}
+
+/* p2p will be supported in a later release ! */
+static int st95hf_tg_configure_hw(struct nfc_digital_dev *ddev,
+ int type,
+ int param)
+{
+ return 0;
+}
+
+static int st95hf_tg_send_cmd(struct nfc_digital_dev *ddev,
+ struct sk_buff *skb,
+ u16 timeout,
+ nfc_digital_cmd_complete_t cb,
+ void *arg)
+{
+ return 0;
+}
+
+static int st95hf_tg_listen(struct nfc_digital_dev *ddev,
+ u16 timeout,
+ nfc_digital_cmd_complete_t cb,
+ void *arg)
+{
+ return 0;
+}
+
+static int st95hf_tg_get_rf_tech(struct nfc_digital_dev *ddev, u8 *rf_tech)
+{
+ return 0;
+}
+
+static int st95hf_switch_rf(struct nfc_digital_dev *ddev, bool on)
+{
+ u8 rf_tech;
+ struct st95hf_context *stcontext = nfc_digital_get_drvdata(ddev);
+
+ rf_tech = ddev->curr_rf_tech;
+
+ if (on)
+ /* switch on RF field */
+ return st95hf_select_protocol(stcontext, rf_tech);
+
+ /* switch OFF RF field */
+ return rf_off(stcontext);
+}
+
+/* TODO st95hf_abort_cmd */
+static void st95hf_abort_cmd(struct nfc_digital_dev *ddev)
+{
+}
+
+static struct nfc_digital_ops st95hf_nfc_digital_ops = {
+ .in_configure_hw = st95hf_in_configure_hw,
+ .in_send_cmd = st95hf_in_send_cmd,
+
+ .tg_listen = st95hf_tg_listen,
+ .tg_configure_hw = st95hf_tg_configure_hw,
+ .tg_send_cmd = st95hf_tg_send_cmd,
+ .tg_get_rf_tech = st95hf_tg_get_rf_tech,
+
+ .switch_rf = st95hf_switch_rf,
+ .abort_cmd = st95hf_abort_cmd,
+};
+
+static const struct spi_device_id st95hf_id[] = {
+ { "st95hf", 0 },
+ {}
+};
+MODULE_DEVICE_TABLE(spi, st95hf_id);
+
+static int st95hf_probe(struct spi_device *nfc_spi_dev)
+{
+ int ret;
+
+ struct st95hf_context *st95context;
+ struct st95hf_spi_context *spicontext;
+
+ nfc_info(&nfc_spi_dev->dev, "ST95HF driver probe called.\n");
+
+ st95context = devm_kzalloc(&nfc_spi_dev->dev,
+ sizeof(struct st95hf_context),
+ GFP_KERNEL);
+ if (!st95context)
+ return -ENOMEM;
+
+ spicontext = &st95context->spicontext;
+
+ spicontext->spidev = nfc_spi_dev;
+
+ st95context->fwi =
+ cmd_array[CMD_ISO14443A_PROTOCOL_SELECT].cmd_params[2];
+
+ if (device_property_present(&nfc_spi_dev->dev, "st95hfvin")) {
+ st95context->st95hf_supply =
+ devm_regulator_get(&nfc_spi_dev->dev,
+ "st95hfvin");
+ if (IS_ERR(st95context->st95hf_supply)) {
+ dev_err(&nfc_spi_dev->dev, "failed to acquire regulator\n");
+ return PTR_ERR(st95context->st95hf_supply);
+ }
+
+ ret = regulator_enable(st95context->st95hf_supply);
+ if (ret) {
+ dev_err(&nfc_spi_dev->dev, "failed to enable regulator\n");
+ return ret;
+ }
+ }
+
+ init_completion(&spicontext->done);
+ mutex_init(&spicontext->spi_lock);
+
+ /*
+ * Store spicontext in spi device object for using it in
+ * remove function
+ */
+ dev_set_drvdata(&nfc_spi_dev->dev, spicontext);
+
+ st95context->enable_gpio =
+ of_get_named_gpio(nfc_spi_dev->dev.of_node,
+ "enable-gpio",
+ 0);
+ if (!gpio_is_valid(st95context->enable_gpio)) {
+ dev_err(&nfc_spi_dev->dev, "No valid enable gpio\n");
+ ret = st95context->enable_gpio;
+ goto err_disable_regulator;
+ }
+
+ ret = devm_gpio_request_one(&nfc_spi_dev->dev, st95context->enable_gpio,
+ GPIOF_DIR_OUT | GPIOF_INIT_HIGH,
+ "enable_gpio");
+ if (ret)
+ goto err_disable_regulator;
+
+ if (nfc_spi_dev->irq > 0) {
+ if (devm_request_threaded_irq(&nfc_spi_dev->dev,
+ nfc_spi_dev->irq,
+ irq_handler,
+ irq_thread_handler,
+ IRQF_TRIGGER_FALLING,
+ "st95hf",
+ (void *)st95context) < 0) {
+ dev_err(&nfc_spi_dev->dev, "err: irq request for st95hf is failed\n");
+ ret = -EINVAL;
+ goto err_disable_regulator;
+ }
+ } else {
+ dev_err(&nfc_spi_dev->dev, "not a valid IRQ associated with ST95HF\n");
+ ret = -EINVAL;
+ goto err_disable_regulator;
+ }
+
+ /*
+ * First reset SPI to handle warm reset of the system.
+ * It will put the ST95HF device in Power ON state
+ * which make the state of device identical to state
+ * at the time of cold reset of the system.
+ */
+ ret = st95hf_send_spi_reset_sequence(st95context);
+ if (ret) {
+ dev_err(&nfc_spi_dev->dev, "err: spi_reset_sequence failed\n");
+ goto err_disable_regulator;
+ }
+
+ /* call PowerOnReset sequence of ST95hf to activate it */
+ ret = st95hf_por_sequence(st95context);
+ if (ret) {
+ dev_err(&nfc_spi_dev->dev, "err: por seq failed for st95hf\n");
+ goto err_disable_regulator;
+ }
+
+ /* create NFC dev object and register with NFC Subsystem */
+ st95context->ddev = nfc_digital_allocate_device(&st95hf_nfc_digital_ops,
+ ST95HF_SUPPORTED_PROT,
+ ST95HF_CAPABILITIES,
+ ST95HF_HEADROOM_LEN,
+ ST95HF_TAILROOM_LEN);
+ if (!st95context->ddev) {
+ ret = -ENOMEM;
+ goto err_disable_regulator;
+ }
+
+ st95context->nfcdev = st95context->ddev->nfc_dev;
+ nfc_digital_set_parent_dev(st95context->ddev, &nfc_spi_dev->dev);
+
+ ret = nfc_digital_register_device(st95context->ddev);
+ if (ret) {
+ dev_err(&st95context->nfcdev->dev, "st95hf registration failed\n");
+ goto err_free_digital_device;
+ }
+
+ /* store st95context in nfc device object */
+ nfc_digital_set_drvdata(st95context->ddev, st95context);
+
+ sema_init(&st95context->exchange_lock, 1);
+ mutex_init(&st95context->rm_lock);
+
+ return ret;
+
+err_free_digital_device:
+ nfc_digital_free_device(st95context->ddev);
+err_disable_regulator:
+ if (st95context->st95hf_supply)
+ regulator_disable(st95context->st95hf_supply);
+
+ return ret;
+}
+
+static int st95hf_remove(struct spi_device *nfc_spi_dev)
+{
+ int result = 0;
+ unsigned char reset_cmd = ST95HF_COMMAND_RESET;
+ struct st95hf_spi_context *spictx = dev_get_drvdata(&nfc_spi_dev->dev);
+
+ struct st95hf_context *stcontext = container_of(spictx,
+ struct st95hf_context,
+ spicontext);
+
+ mutex_lock(&stcontext->rm_lock);
+
+ nfc_digital_unregister_device(stcontext->ddev);
+ nfc_digital_free_device(stcontext->ddev);
+ stcontext->nfcdev_free = true;
+
+ mutex_unlock(&stcontext->rm_lock);
+
+ /* if last in_send_cmd's ISR is pending, wait for it to finish */
+ result = down_killable(&stcontext->exchange_lock);
+ if (result == -EINTR)
+ dev_err(&spictx->spidev->dev, "sleep for semaphore interrupted by signal\n");
+
+ /* next reset the ST95HF controller */
+ result = st95hf_spi_send(&stcontext->spicontext,
+ &reset_cmd,
+ ST95HF_RESET_CMD_LEN,
+ ASYNC);
+ if (result) {
+ dev_err(&spictx->spidev->dev,
+ "ST95HF reset failed in remove() err = %d\n", result);
+ return result;
+ }
+
+ /* wait for 3 ms to complete the controller reset process */
+ usleep_range(3000, 4000);
+
+ /* disable regulator */
+ if (stcontext->st95hf_supply)
+ regulator_disable(stcontext->st95hf_supply);
+
+ return result;
+}
+
+/* Register as SPI protocol driver */
+static struct spi_driver st95hf_driver = {
+ .driver = {
+ .name = "st95hf",
+ .owner = THIS_MODULE,
+ },
+ .id_table = st95hf_id,
+ .probe = st95hf_probe,
+ .remove = st95hf_remove,
+};
+
+module_spi_driver(st95hf_driver);
+
+MODULE_AUTHOR("Shikha Singh <shikha.singh@st.com>");
+MODULE_DESCRIPTION("ST NFC Transceiver ST95HF driver");
+MODULE_LICENSE("GPL v2");
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