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alistair23-linux/drivers/nfc/st95hf/core.c
Thomas Gleixner 46fe777164 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 399 
Based on 1 normalized pattern(s):

  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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 33 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531081038.745679586@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-05 17:37:12 +02:00

1266 lines
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// SPDX-License-Identifier: GPL-2.0-only
/*
* --------------------------------------------------------------------
* Driver for ST NFC Transceiver ST95HF
* --------------------------------------------------------------------
* Copyright (C) 2015 STMicroelectronics Pvt. Ltd. All rights reserved.
*/
#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 st95hf_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 st95hf_irq_thread_handler(int irq, void *st95hfcontext)
{
int result = 0;
int res_len;
static bool wtx;
struct device *spidevice;
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;
}
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_u8(skb, 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 const struct of_device_id st95hf_spi_of_match[] = {
{ .compatible = "st,st95hf" },
{ },
};
MODULE_DEVICE_TABLE(of, st95hf_spi_of_match);
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,
st95hf_irq_handler,
st95hf_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,
.of_match_table = of_match_ptr(st95hf_spi_of_match),
},
.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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