diff options
Diffstat (limited to 'drivers/nfc/pn544.c')
| -rw-r--r-- | drivers/nfc/pn544.c | 891 |
1 files changed, 891 insertions, 0 deletions
diff --git a/drivers/nfc/pn544.c b/drivers/nfc/pn544.c new file mode 100644 index 000000000000..401c44b6eadb --- /dev/null +++ b/drivers/nfc/pn544.c @@ -0,0 +1,891 @@ +/* + * 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[2]; + + 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; + unsigned int buflen; +}; + +static const char reg_vdd_io[] = "Vdd_IO"; +static const char reg_vbat[] = "VBat"; + +/* 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; + 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); |