- 根目录:
- drivers
- nfc
- pn544.c
/*
* Driver for the PN544 NFC chip.
*
* Copyright (C) Nokia Corporation
*
* Author: Jari Vanhala <ext-jari.vanhala@nokia.com>
* Contact: Matti Aaltonen <matti.j.aaltonen@nokia.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms 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, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/completion.h>
#include <linux/crc-ccitt.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/miscdevice.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/nfc/pn544.h>
#include <linux/poll.h>
#include <linux/regulator/consumer.h>
#include <linux/serial_core.h> /* for TCGETS */
#include <linux/slab.h>
#define DRIVER_CARD "PN544 NFC"
#define DRIVER_DESC "NFC driver for PN544"
static struct i2c_device_id pn544_id_table[] = {
{ PN544_DRIVER_NAME, 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, pn544_id_table);
#define HCI_MODE 0
#define FW_MODE 1
enum pn544_state {
PN544_ST_COLD,
PN544_ST_FW_READY,
PN544_ST_READY,
};
enum pn544_irq {
PN544_NONE,
PN544_INT,
};
struct pn544_info {
struct miscdevice miscdev;
struct i2c_client *i2c_dev;
struct regulator_bulk_data regs[3];
enum pn544_state state;
wait_queue_head_t read_wait;
loff_t read_offset;
enum pn544_irq read_irq;
struct mutex read_mutex; /* Serialize read_irq access */
struct mutex mutex; /* Serialize info struct access */
u8 *buf;
size_t buflen;
};
static const char reg_vdd_io[] = "Vdd_IO";
static const char reg_vbat[] = "VBat";
static const char reg_vsim[] = "VSim";
/* sysfs interface */
static ssize_t pn544_test(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct pn544_info *info = dev_get_drvdata(dev);
struct i2c_client *client = info->i2c_dev;
struct pn544_nfc_platform_data *pdata = client->dev.platform_data;
return snprintf(buf, PAGE_SIZE, "%d\n", pdata->test());
}
static int pn544_enable(struct pn544_info *info, int mode)
{
struct pn544_nfc_platform_data *pdata;
struct i2c_client *client = info->i2c_dev;
int r;
r = regulator_bulk_enable(ARRAY_SIZE(info->regs), info->regs);
if (r < 0)
return r;
pdata = client->dev.platform_data;
info->read_irq = PN544_NONE;
if (pdata->enable)
pdata->enable(mode);
if (mode) {
info->state = PN544_ST_FW_READY;
dev_dbg(&client->dev, "now in FW-mode\n");
} else {
info->state = PN544_ST_READY;
dev_dbg(&client->dev, "now in HCI-mode\n");
}
usleep_range(10000, 15000);
return 0;
}
static void pn544_disable(struct pn544_info *info)
{
struct pn544_nfc_platform_data *pdata;
struct i2c_client *client = info->i2c_dev;
pdata = client->dev.platform_data;
if (pdata->disable)
pdata->disable();
info->state = PN544_ST_COLD;
dev_dbg(&client->dev, "Now in OFF-mode\n");
msleep(PN544_RESETVEN_TIME);
info->read_irq = PN544_NONE;
regulator_bulk_disable(ARRAY_SIZE(info->regs), info->regs);
}
static int check_crc(u8 *buf, int buflen)
{
u8 len;
u16 crc;
len = buf[0] + 1;
if (len < 4 || len != buflen || len > PN544_MSG_MAX_SIZE) {
pr_err(PN544_DRIVER_NAME
": CRC; corrupt packet len %u (%d)\n", len, buflen);
print_hex_dump(KERN_DEBUG, "crc: ", DUMP_PREFIX_NONE,
16, 2, buf, buflen, false);
return -EPERM;
}
crc = crc_ccitt(0xffff, buf, len - 2);
crc = ~crc;
if (buf[len-2] != (crc & 0xff) || buf[len-1] != (crc >> 8)) {
pr_err(PN544_DRIVER_NAME ": CRC error 0x%x != 0x%x 0x%x\n",
crc, buf[len-1], buf[len-2]);
print_hex_dump(KERN_DEBUG, "crc: ", DUMP_PREFIX_NONE,
16, 2, buf, buflen, false);
return -EPERM;
}
return 0;
}
static int pn544_i2c_write(struct i2c_client *client, u8 *buf, int len)
{
int r;
if (len < 4 || len != (buf[0] + 1)) {
dev_err(&client->dev, "%s: Illegal message length: %d\n",
__func__, len);
return -EINVAL;
}
if (check_crc(buf, len))
return -EINVAL;
usleep_range(3000, 6000);
r = i2c_master_send(client, buf, len);
dev_dbg(&client->dev, "send: %d\n", r);
if (r == -EREMOTEIO) { /* Retry, chip was in standby */
usleep_range(6000, 10000);
r = i2c_master_send(client, buf, len);
dev_dbg(&client->dev, "send2: %d\n", r);
}
if (r != len)
return -EREMOTEIO;
return r;
}
static int pn544_i2c_read(struct i2c_client *client, u8 *buf, int buflen)
{
int r;
u8 len;
/*
* You could read a packet in one go, but then you'd need to read
* max size and rest would be 0xff fill, so we do split reads.
*/
r = i2c_master_recv(client, &len, 1);
dev_dbg(&client->dev, "recv1: %d\n", r);
if (r != 1)
return -EREMOTEIO;
if (len < PN544_LLC_HCI_OVERHEAD)
len = PN544_LLC_HCI_OVERHEAD;
else if (len > (PN544_MSG_MAX_SIZE - 1))
len = PN544_MSG_MAX_SIZE - 1;
if (1 + len > buflen) /* len+(data+crc16) */
return -EMSGSIZE;
buf[0] = len;
r = i2c_master_recv(client, buf + 1, len);
dev_dbg(&client->dev, "recv2: %d\n", r);
if (r != len)
return -EREMOTEIO;
usleep_range(3000, 6000);
return r + 1;
}
static int pn544_fw_write(struct i2c_client *client, u8 *buf, int len)
{
int r;
dev_dbg(&client->dev, "%s\n", __func__);
if (len < PN544_FW_HEADER_SIZE ||
(PN544_FW_HEADER_SIZE + (buf[1] << 8) + buf[2]) != len)
return -EINVAL;
r = i2c_master_send(client, buf, len);
dev_dbg(&client->dev, "fw send: %d\n", r);
if (r == -EREMOTEIO) { /* Retry, chip was in standby */
usleep_range(6000, 10000);
r = i2c_master_send(client, buf, len);
dev_dbg(&client->dev, "fw send2: %d\n", r);
}
if (r != len)
return -EREMOTEIO;
return r;
}
static int pn544_fw_read(struct i2c_client *client, u8 *buf, int buflen)
{
int r, len;
if (buflen < PN544_FW_HEADER_SIZE)
return -EINVAL;
r = i2c_master_recv(client, buf, PN544_FW_HEADER_SIZE);
dev_dbg(&client->dev, "FW recv1: %d\n", r);
if (r < 0)
return r;
if (r < PN544_FW_HEADER_SIZE)
return -EINVAL;
len = (buf[1] << 8) + buf[2];
if (len == 0) /* just header, no additional data */
return r;
if (len > buflen - PN544_FW_HEADER_SIZE)
return -EMSGSIZE;
r = i2c_master_recv(client, buf + PN544_FW_HEADER_SIZE, len);
dev_dbg(&client->dev, "fw recv2: %d\n", r);
if (r != len)
return -EINVAL;
return r + PN544_FW_HEADER_SIZE;
}
static irqreturn_t pn544_irq_thread_fn(int irq, void *dev_id)
{
struct pn544_info *info = dev_id;
struct i2c_client *client = info->i2c_dev;
BUG_ON(!info);
BUG_ON(irq != info->i2c_dev->irq);
dev_dbg(&client->dev, "IRQ\n");
mutex_lock(&info->read_mutex);
info->read_irq = PN544_INT;
mutex_unlock(&info->read_mutex);
wake_up_interruptible(&info->read_wait);
return IRQ_HANDLED;
}
static enum pn544_irq pn544_irq_state(struct pn544_info *info)
{
enum pn544_irq irq;
mutex_lock(&info->read_mutex);
irq = info->read_irq;
mutex_unlock(&info->read_mutex);
/*
* XXX: should we check GPIO-line status directly?
* return pdata->irq_status() ? PN544_INT : PN544_NONE;
*/
return irq;
}
static ssize_t pn544_read(struct file *file, char __user *buf,
size_t count, loff_t *offset)
{
struct pn544_info *info = container_of(file->private_data,
struct pn544_info, miscdev);
struct i2c_client *client = info->i2c_dev;
enum pn544_irq irq;
size_t len;
int r = 0;
dev_dbg(&client->dev, "%s: info: %p, count: %zu\n", __func__,
info, count);
mutex_lock(&info->mutex);
if (info->state == PN544_ST_COLD) {
r = -ENODEV;
goto out;
}
irq = pn544_irq_state(info);
if (irq == PN544_NONE) {
if (file->f_flags & O_NONBLOCK) {
r = -EAGAIN;
goto out;
}
if (wait_event_interruptible(info->read_wait,
(info->read_irq == PN544_INT))) {
r = -ERESTARTSYS;
goto out;
}
}
if (info->state == PN544_ST_FW_READY) {
len = min(count, info->buflen);
mutex_lock(&info->read_mutex);
r = pn544_fw_read(info->i2c_dev, info->buf, len);
info->read_irq = PN544_NONE;
mutex_unlock(&info->read_mutex);
if (r < 0) {
dev_err(&info->i2c_dev->dev, "FW read failed: %d\n", r);
goto out;
}
print_hex_dump(KERN_DEBUG, "FW read: ", DUMP_PREFIX_NONE,
16, 2, info->buf, r, false);
*offset += r;
if (copy_to_user(buf, info->buf, r)) {
r = -EFAULT;
goto out;
}
} else {
len = min(count, info->buflen);
mutex_lock(&info->read_mutex);
r = pn544_i2c_read(info->i2c_dev, info->buf, len);
info->read_irq = PN544_NONE;
mutex_unlock(&info->read_mutex);
if (r < 0) {
dev_err(&info->i2c_dev->dev, "read failed (%d)\n", r);
goto out;
}
print_hex_dump(KERN_DEBUG, "read: ", DUMP_PREFIX_NONE,
16, 2, info->buf, r, false);
*offset += r;
if (copy_to_user(buf, info->buf, r)) {
r = -EFAULT;
goto out;
}
}
out:
mutex_unlock(&info->mutex);
return r;
}
static unsigned int pn544_poll(struct file *file, poll_table *wait)
{
struct pn544_info *info = container_of(file->private_data,
struct pn544_info, miscdev);
struct i2c_client *client = info->i2c_dev;
int r = 0;
dev_dbg(&client->dev, "%s: info: %p\n", __func__, info);
mutex_lock(&info->mutex);
if (info->state == PN544_ST_COLD) {
r = -ENODEV;
goto out;
}
poll_wait(file, &info->read_wait, wait);
if (pn544_irq_state(info) == PN544_INT) {
r = POLLIN | POLLRDNORM;
goto out;
}
out:
mutex_unlock(&info->mutex);
return r;
}
static ssize_t pn544_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
struct pn544_info *info = container_of(file->private_data,
struct pn544_info, miscdev);
struct i2c_client *client = info->i2c_dev;
ssize_t len;
int r;
dev_dbg(&client->dev, "%s: info: %p, count %zu\n", __func__,
info, count);
mutex_lock(&info->mutex);
if (info->state == PN544_ST_COLD) {
r = -ENODEV;
goto out;
}
/*
* XXX: should we detect rset-writes and clean possible
* read_irq state
*/
if (info->state == PN544_ST_FW_READY) {
size_t fw_len;
if (count < PN544_FW_HEADER_SIZE) {
r = -EINVAL;
goto out;
}
len = min(count, info->buflen);
if (copy_from_user(info->buf, buf, len)) {
r = -EFAULT;
goto out;
}
print_hex_dump(KERN_DEBUG, "FW write: ", DUMP_PREFIX_NONE,
16, 2, info->buf, len, false);
fw_len = PN544_FW_HEADER_SIZE + (info->buf[1] << 8) +
info->buf[2];
if (len > fw_len) /* 1 msg at a time */
len = fw_len;
r = pn544_fw_write(info->i2c_dev, info->buf, len);
} else {
if (count < PN544_LLC_MIN_SIZE) {
r = -EINVAL;
goto out;
}
len = min(count, info->buflen);
if (copy_from_user(info->buf, buf, len)) {
r = -EFAULT;
goto out;
}
print_hex_dump(KERN_DEBUG, "write: ", DUMP_PREFIX_NONE,
16, 2, info->buf, len, false);
if (len > (info->buf[0] + 1)) /* 1 msg at a time */
len = info->buf[0] + 1;
r = pn544_i2c_write(info->i2c_dev, info->buf, len);
}
out:
mutex_unlock(&info->mutex);
return r;
}
static long pn544_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
struct pn544_info *info = container_of(file->private_data,
struct pn544_info, miscdev);
struct i2c_client *client = info->i2c_dev;
struct pn544_nfc_platform_data *pdata;
unsigned int val;
int r = 0;
dev_dbg(&client->dev, "%s: info: %p, cmd: 0x%x\n", __func__, info, cmd);
mutex_lock(&info->mutex);
if (info->state == PN544_ST_COLD) {
r = -ENODEV;
goto out;
}
pdata = info->i2c_dev->dev.platform_data;
switch (cmd) {
case PN544_GET_FW_MODE:
dev_dbg(&client->dev, "%s: PN544_GET_FW_MODE\n", __func__);
val = (info->state == PN544_ST_FW_READY);
if (copy_to_user((void __user *)arg, &val, sizeof(val))) {
r = -EFAULT;
goto out;
}
break;
case PN544_SET_FW_MODE:
dev_dbg(&client->dev, "%s: PN544_SET_FW_MODE\n", __func__);
if (copy_from_user(&val, (void __user *)arg, sizeof(val))) {
r = -EFAULT;
goto out;
}
if (val) {
if (info->state == PN544_ST_FW_READY)
break;
pn544_disable(info);
r = pn544_enable(info, FW_MODE);
if (r < 0)
goto out;
} else {
if (info->state == PN544_ST_READY)
break;
pn544_disable(info);
r = pn544_enable(info, HCI_MODE);
if (r < 0)
goto out;
}
file->f_pos = info->read_offset;
break;
case TCGETS:
dev_dbg(&client->dev, "%s: TCGETS\n", __func__);
r = -ENOIOCTLCMD;
break;
default:
dev_err(&client->dev, "Unknown ioctl 0x%x\n", cmd);
r = -ENOIOCTLCMD;
break;
}
out:
mutex_unlock(&info->mutex);
return r;
}
static int pn544_open(struct inode *inode, struct file *file)
{
struct pn544_info *info = container_of(file->private_data,
struct pn544_info, miscdev);
struct i2c_client *client = info->i2c_dev;
int r = 0;
dev_dbg(&client->dev, "%s: info: %p, client %p\n", __func__,
info, info->i2c_dev);
mutex_lock(&info->mutex);
/*
* Only 1 at a time.
* XXX: maybe user (counter) would work better
*/
if (info->state != PN544_ST_COLD) {
r = -EBUSY;
goto out;
}
file->f_pos = info->read_offset;
r = pn544_enable(info, HCI_MODE);
out:
mutex_unlock(&info->mutex);
return r;
}
static int pn544_close(struct inode *inode, struct file *file)
{
struct pn544_info *info = container_of(file->private_data,
struct pn544_info, miscdev);
struct i2c_client *client = info->i2c_dev;
dev_dbg(&client->dev, "%s: info: %p, client %p\n",
__func__, info, info->i2c_dev);
mutex_lock(&info->mutex);
pn544_disable(info);
mutex_unlock(&info->mutex);
return 0;
}
static const struct file_operations pn544_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.read = pn544_read,
.write = pn544_write,
.poll = pn544_poll,
.open = pn544_open,
.release = pn544_close,
.unlocked_ioctl = pn544_ioctl,
};
#ifdef CONFIG_PM
static int pn544_suspend(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct pn544_info *info;
int r = 0;
dev_info(&client->dev, "***\n%s: client %p\n***\n", __func__, client);
info = i2c_get_clientdata(client);
dev_info(&client->dev, "%s: info: %p, client %p\n", __func__,
info, client);
mutex_lock(&info->mutex);
switch (info->state) {
case PN544_ST_FW_READY:
/* Do not suspend while upgrading FW, please! */
r = -EPERM;
break;
case PN544_ST_READY:
/*
* CHECK: Device should be in standby-mode. No way to check?
* Allowing low power mode for the regulator is potentially
* dangerous if pn544 does not go to suspension.
*/
break;
case PN544_ST_COLD:
break;
};
mutex_unlock(&info->mutex);
return r;
}
static int pn544_resume(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct pn544_info *info = i2c_get_clientdata(client);
int r = 0;
dev_dbg(&client->dev, "%s: info: %p, client %p\n", __func__,
info, client);
mutex_lock(&info->mutex);
switch (info->state) {
case PN544_ST_READY:
/*
* CHECK: If regulator low power mode is allowed in
* pn544_suspend, we should go back to normal mode
* here.
*/
break;
case PN544_ST_COLD:
break;
case PN544_ST_FW_READY:
break;
};
mutex_unlock(&info->mutex);
return r;
}
static SIMPLE_DEV_PM_OPS(pn544_pm_ops, pn544_suspend, pn544_resume);
#endif
static struct device_attribute pn544_attr =
__ATTR(nfc_test, S_IRUGO, pn544_test, NULL);
static int __devinit pn544_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct pn544_info *info;
struct pn544_nfc_platform_data *pdata;
int r = 0;
dev_dbg(&client->dev, "%s\n", __func__);
dev_dbg(&client->dev, "IRQ: %d\n", client->irq);
/* private data allocation */
info = kzalloc(sizeof(struct pn544_info), GFP_KERNEL);
if (!info) {
dev_err(&client->dev,
"Cannot allocate memory for pn544_info.\n");
r = -ENOMEM;
goto err_info_alloc;
}
info->buflen = max(PN544_MSG_MAX_SIZE, PN544_MAX_I2C_TRANSFER);
info->buf = kzalloc(info->buflen, GFP_KERNEL);
if (!info->buf) {
dev_err(&client->dev,
"Cannot allocate memory for pn544_info->buf.\n");
r = -ENOMEM;
goto err_buf_alloc;
}
info->regs[0].supply = reg_vdd_io;
info->regs[1].supply = reg_vbat;
info->regs[2].supply = reg_vsim;
r = regulator_bulk_get(&client->dev, ARRAY_SIZE(info->regs),
info->regs);
if (r < 0)
goto err_kmalloc;
info->i2c_dev = client;
info->state = PN544_ST_COLD;
info->read_irq = PN544_NONE;
mutex_init(&info->read_mutex);
mutex_init(&info->mutex);
init_waitqueue_head(&info->read_wait);
i2c_set_clientdata(client, info);
pdata = client->dev.platform_data;
if (!pdata) {
dev_err(&client->dev, "No platform data\n");
r = -EINVAL;
goto err_reg;
}
if (!pdata->request_resources) {
dev_err(&client->dev, "request_resources() missing\n");
r = -EINVAL;
goto err_reg;
}
r = pdata->request_resources(client);
if (r) {
dev_err(&client->dev, "Cannot get platform resources\n");
goto err_reg;
}
r = request_threaded_irq(client->irq, NULL, pn544_irq_thread_fn,
IRQF_TRIGGER_RISING, PN544_DRIVER_NAME,
info);
if (r < 0) {
dev_err(&client->dev, "Unable to register IRQ handler\n");
goto err_res;
}
/* If we don't have the test we don't need the sysfs file */
if (pdata->test) {
r = device_create_file(&client->dev, &pn544_attr);
if (r) {
dev_err(&client->dev,
"sysfs registration failed, error %d\n", r);
goto err_irq;
}
}
info->miscdev.minor = MISC_DYNAMIC_MINOR;
info->miscdev.name = PN544_DRIVER_NAME;
info->miscdev.fops = &pn544_fops;
info->miscdev.parent = &client->dev;
r = misc_register(&info->miscdev);
if (r < 0) {
dev_err(&client->dev, "Device registration failed\n");
goto err_sysfs;
}
dev_dbg(&client->dev, "%s: info: %p, pdata %p, client %p\n",
__func__, info, pdata, client);
return 0;
err_sysfs:
if (pdata->test)
device_remove_file(&client->dev, &pn544_attr);
err_irq:
free_irq(client->irq, info);
err_res:
if (pdata->free_resources)
pdata->free_resources();
err_reg:
regulator_bulk_free(ARRAY_SIZE(info->regs), info->regs);
err_kmalloc:
kfree(info->buf);
err_buf_alloc:
kfree(info);
err_info_alloc:
return r;
}
static __devexit int pn544_remove(struct i2c_client *client)
{
struct pn544_info *info = i2c_get_clientdata(client);
struct pn544_nfc_platform_data *pdata = client->dev.platform_data;
dev_dbg(&client->dev, "%s\n", __func__);
misc_deregister(&info->miscdev);
if (pdata->test)
device_remove_file(&client->dev, &pn544_attr);
if (info->state != PN544_ST_COLD) {
if (pdata->disable)
pdata->disable();
info->read_irq = PN544_NONE;
}
free_irq(client->irq, info);
if (pdata->free_resources)
pdata->free_resources();
regulator_bulk_free(ARRAY_SIZE(info->regs), info->regs);
kfree(info->buf);
kfree(info);
return 0;
}
static struct i2c_driver pn544_driver = {
.driver = {
.name = PN544_DRIVER_NAME,
#ifdef CONFIG_PM
.pm = &pn544_pm_ops,
#endif
},
.probe = pn544_probe,
.id_table = pn544_id_table,
.remove = __devexit_p(pn544_remove),
};
static int __init pn544_init(void)
{
int r;
pr_debug(DRIVER_DESC ": %s\n", __func__);
r = i2c_add_driver(&pn544_driver);
if (r) {
pr_err(PN544_DRIVER_NAME ": driver registration failed\n");
return r;
}
return 0;
}
static void __exit pn544_exit(void)
{
i2c_del_driver(&pn544_driver);
pr_info(DRIVER_DESC ", Exiting.\n");
}
module_init(pn544_init);
module_exit(pn544_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION(DRIVER_DESC);