Commit 0329326e authored by Matti J. Aaltonen's avatar Matti J. Aaltonen Committed by Linus Torvalds

NFC: Driver for NXP Semiconductors PN544 NFC chip.

Creates a new "Near Field Communication" subsystem in drivers/nfc.
http://en.wikipedia.org/wiki/Near_Field_Communication is useful ;)

This is a driver for the pn544 NFC device. The driver transfers
ETSI messages between the device and the user space.
Signed-off-by: default avatarMatti J. Aaltonen <matti.j.aaltonen@nokia.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 6164281a
Kernel driver for the NXP Semiconductors PN544 Near Field
Communication chip
Author: Jari Vanhala
Contact: Matti Aaltonen (matti.j.aaltonen at nokia.com)
General
-------
The PN544 is an integrated transmission module for contactless
communication. The driver goes under drives/nfc/ and is compiled as a
module named "pn544". It registers a misc device and creates a device
file named "/dev/pn544".
Host Interfaces: I2C, SPI and HSU, this driver supports currently only I2C.
The Interface
-------------
The driver offers a sysfs interface for a hardware test and an IOCTL
interface for selecting between two operating modes. There are read,
write and poll functions for transferring messages. The two operating
modes are the normal (HCI) mode and the firmware update mode.
PN544 is controlled by sending messages from the userspace to the
chip. The main function of the driver is just to pass those messages
without caring about the message content.
Protocols
---------
In the normal (HCI) mode and in the firmware update mode read and
write functions behave a bit differently because the message formats
or the protocols are different.
In the normal (HCI) mode the protocol used is derived from the ETSI
HCI specification. The firmware is updated using a specific protocol,
which is different from HCI.
HCI messages consist of an eight bit header and the message body. The
header contains the message length. Maximum size for an HCI message is
33. In HCI mode sent messages are tested for a correct
checksum. Firmware update messages have the length in the second (MSB)
and third (LSB) bytes of the message. The maximum FW message length is
1024 bytes.
For the ETSI HCI specification see
http://www.etsi.org/WebSite/Technologies/ProtocolSpecification.aspx
The Hardware Test
-----------------
The idea of the test is that it can performed by reading from the
corresponding sysfs file. The test is implemented in the board file
and it should test that PN544 can be put into the firmware update
mode. If the test is not implemented the sysfs file does not get
created.
Example:
> cat /sys/module/pn544/drivers/i2c\:pn544/3-002b/nfc_test
1
Normal Operation
----------------
PN544 is powered up when the device file is opened, otherwise it's
turned off. Only one instance can use the device at a time.
Userspace applications control PN544 with HCI messages. The hardware
sends an interrupt when data is available for reading. Data is
physically read when the read function is called by a userspace
application. Poll() checks the read interrupt state. Configuration and
self testing are also done from the userspace using read and write.
Example platform data:
static int rx71_pn544_nfc_request_resources(struct i2c_client *client)
{
/* Get and setup the HW resources for the device */
}
static void rx71_pn544_nfc_free_resources(void)
{
/* Release the HW resources */
}
static void rx71_pn544_nfc_enable(int fw)
{
/* Turn the device on */
}
static int rx71_pn544_nfc_test(void)
{
/*
* Put the device into the FW update mode
* and then back to the normal mode.
* Check the behavior and return one on success,
* zero on failure.
*/
}
static void rx71_pn544_nfc_disable(void)
{
/* turn the power off */
}
static struct pn544_nfc_platform_data rx71_nfc_data = {
.request_resources = rx71_pn544_nfc_request_resources,
.free_resources = rx71_pn544_nfc_free_resources,
.enable = rx71_pn544_nfc_enable,
.test = rx71_pn544_nfc_test,
.disable = rx71_pn544_nfc_disable,
};
...@@ -88,6 +88,8 @@ source "drivers/memstick/Kconfig" ...@@ -88,6 +88,8 @@ source "drivers/memstick/Kconfig"
source "drivers/leds/Kconfig" source "drivers/leds/Kconfig"
source "drivers/nfc/Kconfig"
source "drivers/accessibility/Kconfig" source "drivers/accessibility/Kconfig"
source "drivers/infiniband/Kconfig" source "drivers/infiniband/Kconfig"
......
...@@ -40,7 +40,7 @@ obj-$(CONFIG_FB_INTEL) += video/intelfb/ ...@@ -40,7 +40,7 @@ obj-$(CONFIG_FB_INTEL) += video/intelfb/
obj-y += serial/ obj-y += serial/
obj-$(CONFIG_PARPORT) += parport/ obj-$(CONFIG_PARPORT) += parport/
obj-y += base/ block/ misc/ mfd/ obj-y += base/ block/ misc/ mfd/ nfc/
obj-$(CONFIG_NUBUS) += nubus/ obj-$(CONFIG_NUBUS) += nubus/
obj-y += macintosh/ obj-y += macintosh/
obj-$(CONFIG_IDE) += ide/ obj-$(CONFIG_IDE) += ide/
......
#
# Near Field Communication (NFC) devices
#
menuconfig NFC_DEVICES
bool "NFC devices"
default n
---help---
You'll have to say Y if your computer contains an NFC device that
you want to use under Linux.
You can say N here if you don't have any Near Field Communication
devices connected to your computer.
if NFC_DEVICES
config PN544_NFC
tristate "PN544 NFC driver"
depends on I2C
select CRC_CCITT
default n
---help---
Say yes if you want PN544 Near Field Communication driver.
This is for i2c connected version. If unsure, say N here.
To compile this driver as a module, choose m here. The module will
be called pn544.
endif # NFC_DEVICES
#
# Makefile for nfc devices
#
obj-$(CONFIG_PN544_NFC) += pn544.o
This diff is collapsed.
/*
* Driver include for the PN544 NFC chip.
*
* Copyright (C) Nokia Corporation
*
* Author: Jari Vanhala <ext-jari.vanhala@nokia.com>
* Contact: Matti Aaltoenn <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
*/
#ifndef _PN544_H_
#define _PN544_H_
#include <linux/i2c.h>
#define PN544_DRIVER_NAME "pn544"
#define PN544_MAXWINDOW_SIZE 7
#define PN544_WINDOW_SIZE 4
#define PN544_RETRIES 10
#define PN544_MAX_I2C_TRANSFER 0x0400
#define PN544_MSG_MAX_SIZE 0x21 /* at normal HCI mode */
/* ioctl */
#define PN544_CHAR_BASE 'P'
#define PN544_IOR(num, dtype) _IOR(PN544_CHAR_BASE, num, dtype)
#define PN544_IOW(num, dtype) _IOW(PN544_CHAR_BASE, num, dtype)
#define PN544_GET_FW_MODE PN544_IOW(1, unsigned int)
#define PN544_SET_FW_MODE PN544_IOW(2, unsigned int)
#define PN544_GET_DEBUG PN544_IOW(3, unsigned int)
#define PN544_SET_DEBUG PN544_IOW(4, unsigned int)
/* Timing restrictions (ms) */
#define PN544_RESETVEN_TIME 30 /* 7 */
#define PN544_PVDDVEN_TIME 0
#define PN544_VBATVEN_TIME 0
#define PN544_GPIO4VEN_TIME 0
#define PN544_WAKEUP_ACK 5
#define PN544_WAKEUP_GUARD (PN544_WAKEUP_ACK + 1)
#define PN544_INACTIVITY_TIME 1000
#define PN544_INTERFRAME_DELAY 200 /* us */
#define PN544_BAUDRATE_CHANGE 150 /* us */
/* Debug bits */
#define PN544_DEBUG_BUF 0x01
#define PN544_DEBUG_READ 0x02
#define PN544_DEBUG_WRITE 0x04
#define PN544_DEBUG_IRQ 0x08
#define PN544_DEBUG_CALLS 0x10
#define PN544_DEBUG_MODE 0x20
/* Normal (HCI) mode */
#define PN544_LLC_HCI_OVERHEAD 3 /* header + crc (to length) */
#define PN544_LLC_MIN_SIZE (1 + PN544_LLC_HCI_OVERHEAD) /* length + */
#define PN544_LLC_MAX_DATA (PN544_MSG_MAX_SIZE - 2)
#define PN544_LLC_MAX_HCI_SIZE (PN544_LLC_MAX_DATA - 2)
struct pn544_llc_packet {
unsigned char length; /* of rest of packet */
unsigned char header;
unsigned char data[PN544_LLC_MAX_DATA]; /* includes crc-ccitt */
};
/* Firmware upgrade mode */
#define PN544_FW_HEADER_SIZE 3
/* max fw transfer is 1024bytes, but I2C limits it to 0xC0 */
#define PN544_MAX_FW_DATA (PN544_MAX_I2C_TRANSFER - PN544_FW_HEADER_SIZE)
struct pn544_fw_packet {
unsigned char command; /* status in answer */
unsigned char length[2]; /* big-endian order (msf) */
unsigned char data[PN544_MAX_FW_DATA];
};
#ifdef __KERNEL__
/* board config */
struct pn544_nfc_platform_data {
int (*request_resources) (struct i2c_client *client);
void (*free_resources) (void);
void (*enable) (int fw);
int (*test) (void);
void (*disable) (void);
};
#endif /* __KERNEL__ */
#endif /* _PN544_H_ */
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