/*
* LIRC driver for ITE8709 CIR port
*
* Copyright (C) 2008 Grégory Lardière <spmf2004-lirc@yahoo.fr>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or (at your option) any later version.
*
* 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/module.h>
#include <linux/interrupt.h>
#include <linux/sched.h>
#include <linux/delay.h>
#include <linux/pnp.h>
#include <linux/io.h>
#include <media/lirc.h>
#include <media/lirc_dev.h>
#define LIRC_DRIVER_NAME "lirc_ite8709"
#define BUF_CHUNK_SIZE sizeof(int)
#define BUF_SIZE (128*BUF_CHUNK_SIZE)
/*
* The ITE8709 device seems to be the combination of IT8512 superIO chip and
* a specific firmware running on the IT8512's embedded micro-controller.
* In addition of the embedded micro-controller, the IT8512 chip contains a
* CIR module and several other modules. A few modules are directly accessible
* by the host CPU, but most of them are only accessible by the
* micro-controller. The CIR module is only accessible by the micro-controller.
* The battery-backed SRAM module is accessible by the host CPU and the
* micro-controller. So one of the MC's firmware role is to act as a bridge
* between the host CPU and the CIR module. The firmware implements a kind of
* communication protocol using the SRAM module as a shared memory. The IT8512
* specification is publicly available on ITE's web site, but the communication
* protocol is not, so it was reverse-engineered.
*/
/* ITE8709 Registers addresses and values (reverse-engineered) */
#define ITE8709_MODE 0x1a
#define ITE8709_REG_ADR 0x1b
#define ITE8709_REG_VAL 0x1c
#define ITE8709_IIR 0x1e /* Interrupt identification register */
#define ITE8709_RFSR 0x1f /* Receiver FIFO status register */
#define ITE8709_FIFO_START 0x20
#define ITE8709_MODE_READY 0X00
#define ITE8709_MODE_WRITE 0X01
#define ITE8709_MODE_READ 0X02
#define ITE8709_IIR_RDAI 0x02 /* Receiver data available interrupt */
#define ITE8709_IIR_RFOI 0x04 /* Receiver FIFO overrun interrupt */
#define ITE8709_RFSR_MASK 0x3f /* FIFO byte count mask */
/*
* IT8512 CIR-module registers addresses and values
* (from IT8512 E/F specification v0.4.1)
*/
#define IT8512_REG_MSTCR 0x01 /* Master control register */
#define IT8512_REG_IER 0x02 /* Interrupt enable register */
#define IT8512_REG_CFR 0x04 /* Carrier frequency register */
#define IT8512_REG_RCR 0x05 /* Receive control register */
#define IT8512_REG_BDLR 0x08 /* Baud rate divisor low byte register */
#define IT8512_REG_BDHR 0x09 /* Baud rate divisor high byte register */
#define IT8512_MSTCR_RESET 0x01 /* Reset registers to default value */
#define IT8512_MSTCR_FIFOCLR 0x02 /* Clear FIFO */
#define IT8512_MSTCR_FIFOTL_7 0x04 /* FIFO threshold level : 7 */
#define IT8512_MSTCR_FIFOTL_25 0x0c /* FIFO threshold level : 25 */
#define IT8512_IER_RDAIE 0x02 /* Enable data interrupt request */
#define IT8512_IER_RFOIE 0x04 /* Enable FIFO overrun interrupt req */
#define IT8512_IER_IEC 0x80 /* Enable interrupt request */
#define IT8512_CFR_CF_36KHZ 0x09 /* Carrier freq : low speed, 36kHz */
#define IT8512_RCR_RXDCR_1 0x01 /* Demodulation carrier range : 1 */
#define IT8512_RCR_RXACT 0x08 /* Receiver active */
#define IT8512_RCR_RXEN 0x80 /* Receiver enable */
#define IT8512_BDR_6 6 /* Baud rate divisor : 6 */
/* Actual values used by this driver */
#define CFG_FIFOTL IT8512_MSTCR_FIFOTL_25
#define CFG_CR_FREQ IT8512_CFR_CF_36KHZ
#define CFG_DCR IT8512_RCR_RXDCR_1
#define CFG_BDR IT8512_BDR_6
#define CFG_TIMEOUT 100000 /* Rearm interrupt when a space is > 100 ms */
static int debug;
struct ite8709_device {
int use_count;
int io;
int irq;
spinlock_t hardware_lock;
__u64 acc_pulse;
__u64 acc_space;
char lastbit;
struct timeval last_tv;
struct lirc_driver driver;
struct tasklet_struct tasklet;
char force_rearm;
char rearmed;
char device_busy;
};
#define dprintk(fmt, args...) \
do { \
if (debug) \
printk(KERN_DEBUG LIRC_DRIVER_NAME ": " \
fmt, ## args); \
} while (0)
static unsigned char ite8709_read(struct ite8709_device *dev,
unsigned char port)
{
outb(port, dev->io);
return inb(dev->io+1);
}
static void ite8709_write(struct ite8709_device *dev, unsigned char port,
unsigned char data)
{
outb(port, dev->io);
outb(data, dev->io+1);
}
static void ite8709_wait_device(struct ite8709_device *dev)
{
int i = 0;
/*
* loop until device tells it's ready to continue
* iterations count is usually ~750 but can sometimes achieve 13000
*/
for (i = 0; i < 15000; i++) {
udelay(2);
if (ite8709_read(dev, ITE8709_MODE) == ITE8709_MODE_READY)
break;
}
}
static void ite8709_write_register(struct ite8709_device *dev,
unsigned char reg_adr, unsigned char reg_value)
{
ite8709_wait_device(dev);
ite8709_write(dev, ITE8709_REG_VAL, reg_value);
ite8709_write(dev, ITE8709_REG_ADR, reg_adr);
ite8709_write(dev, ITE8709_MODE, ITE8709_MODE_WRITE);
}
static void ite8709_init_hardware(struct ite8709_device *dev)
{
spin_lock_irq(&dev->hardware_lock);
dev->device_busy = 1;
spin_unlock_irq(&dev->hardware_lock);
ite8709_write_register(dev, IT8512_REG_BDHR, (CFG_BDR >> 8) & 0xff);
ite8709_write_register(dev, IT8512_REG_BDLR, CFG_BDR & 0xff);
ite8709_write_register(dev, IT8512_REG_CFR, CFG_CR_FREQ);
ite8709_write_register(dev, IT8512_REG_IER,
IT8512_IER_IEC | IT8512_IER_RFOIE | IT8512_IER_RDAIE);
ite8709_write_register(dev, IT8512_REG_RCR, CFG_DCR);
ite8709_write_register(dev, IT8512_REG_MSTCR,
CFG_FIFOTL | IT8512_MSTCR_FIFOCLR);
ite8709_write_register(dev, IT8512_REG_RCR,
IT8512_RCR_RXEN | IT8512_RCR_RXACT | CFG_DCR);
spin_lock_irq(&dev->hardware_lock);
dev->device_busy = 0;
spin_unlock_irq(&dev->hardware_lock);
tasklet_enable(&dev->tasklet);
}
static void ite8709_drop_hardware(struct ite8709_device *dev)
{
tasklet_disable(&dev->tasklet);
spin_lock_irq(&dev->hardware_lock);
dev->device_busy = 1;
spin_unlock_irq(&dev->hardware_lock);
ite8709_write_register(dev, IT8512_REG_RCR, 0);
ite8709_write_register(dev, IT8512_REG_MSTCR,
IT8512_MSTCR_RESET | IT8512_MSTCR_FIFOCLR);
spin_lock_irq(&dev->hardware_lock);
dev->device_busy = 0;
spin_unlock_irq(&dev->hardware_lock);
}
static int ite8709_set_use_inc(void *data)
{
struct ite8709_device *dev;
dev = data;
if (dev->use_count == 0)
ite8709_init_hardware(dev);
dev->use_count++;
return 0;
}
static void ite8709_set_use_dec(void *data)
{
struct ite8709_device *dev;
dev = data;
dev->use_count--;
if (dev->use_count == 0)
ite8709_drop_hardware(dev);
}
static void ite8709_add_read_queue(struct ite8709_device *dev, int flag,
__u64 val)
{
int value;
dprintk("add a %llu usec %s\n", val, flag ? "pulse" : "space");
value = (val > PULSE_MASK) ? PULSE_MASK : val;
if (flag)
value |= PULSE_BIT;
if (!lirc_buffer_full(dev->driver.rbuf)) {
lirc_buffer_write(dev->driver.rbuf, (void *) &value);
wake_up(&dev->driver.rbuf->wait_poll);
}
}
static irqreturn_t ite8709_interrupt(int irq, void *dev_id)
{
unsigned char data;
int iir, rfsr, i;
int fifo = 0;
char bit;
struct timeval curr_tv;
/* Bit duration in microseconds */
const unsigned long bit_duration = 1000000ul / (115200 / CFG_BDR);
struct ite8709_device *dev;
dev = dev_id;
/*
* If device is busy, we simply discard data because we are in one of
* these two cases : shutting down or rearming the device, so this
* doesn't really matter and this avoids waiting too long in IRQ ctx
*/
spin_lock(&dev->hardware_lock);
if (dev->device_busy) {
spin_unlock(&dev->hardware_lock);
return IRQ_RETVAL(IRQ_HANDLED);
}
iir = ite8709_read(dev, ITE8709_IIR);
switch (iir) {
case ITE8709_IIR_RFOI:
dprintk("fifo overrun, scheduling forced rearm just in case\n");
dev->force_rearm = 1;
tasklet_schedule(&dev->tasklet);
spin_unlock(&dev->hardware_lock);
return IRQ_RETVAL(IRQ_HANDLED);
case ITE8709_IIR_RDAI:
rfsr = ite8709_read(dev, ITE8709_RFSR);
fifo = rfsr & ITE8709_RFSR_MASK;
if (fifo > 32)
fifo = 32;
dprintk("iir: 0x%x rfsr: 0x%x fifo: %d\n", iir, rfsr, fifo);
if (dev->rearmed) {
do_gettimeofday(&curr_tv);
dev->acc_space += 1000000ull
* (curr_tv.tv_sec - dev->last_tv.tv_sec)
+ (curr_tv.tv_usec - dev->last_tv.tv_usec);
dev->rearmed = 0;
}
for (i = 0; i < fifo; i++) {
data = ite8709_read(dev, i+ITE8709_FIFO_START);
data = ~data;
/* Loop through */
for (bit = 0; bit < 8; ++bit) {
if ((data >> bit) & 1) {
dev->acc_pulse += bit_duration;
if (dev->lastbit == 0) {
ite8709_add_read_queue(dev, 0,
dev->acc_space);
dev->acc_space = 0;
}
} else {
dev->acc_space += bit_duration;
if (dev->lastbit == 1) {
ite8709_add_read_queue(dev, 1,
dev->acc_pulse);
dev->acc_pulse = 0;
}
}
dev->lastbit = (data >> bit) & 1;
}
}
ite8709_write(dev, ITE8709_RFSR, 0);
if (dev->acc_space > CFG_TIMEOUT) {
dprintk("scheduling rearm IRQ\n");
do_gettimeofday(&dev->last_tv);
dev->force_rearm = 0;
tasklet_schedule(&dev->tasklet);
}
spin_unlock(&dev->hardware_lock);
return IRQ_RETVAL(IRQ_HANDLED);
default:
/* not our irq */
dprintk("unknown IRQ (shouldn't happen) !!\n");
spin_unlock(&dev->hardware_lock);
return IRQ_RETVAL(IRQ_NONE);
}
}
static void ite8709_rearm_irq(unsigned long data)
{
struct ite8709_device *dev;
unsigned long flags;
dev = (struct ite8709_device *) data;
spin_lock_irqsave(&dev->hardware_lock, flags);
dev->device_busy = 1;
spin_unlock_irqrestore(&dev->hardware_lock, flags);
if (dev->force_rearm || dev->acc_space > CFG_TIMEOUT) {
dprintk("rearming IRQ\n");
ite8709_write_register(dev, IT8512_REG_RCR,
IT8512_RCR_RXACT | CFG_DCR);
ite8709_write_register(dev, IT8512_REG_MSTCR,
CFG_FIFOTL | IT8512_MSTCR_FIFOCLR);
ite8709_write_register(dev, IT8512_REG_RCR,
IT8512_RCR_RXEN | IT8512_RCR_RXACT | CFG_DCR);
if (!dev->force_rearm)
dev->rearmed = 1;
dev->force_rearm = 0;
}
spin_lock_irqsave(&dev->hardware_lock, flags);
dev->device_busy = 0;
spin_unlock_irqrestore(&dev->hardware_lock, flags);
}
static int ite8709_cleanup(struct ite8709_device *dev, int stage, int errno,
char *msg)
{
if (msg != NULL)
printk(KERN_ERR LIRC_DRIVER_NAME ": %s\n", msg);
switch (stage) {
case 6:
if (dev->use_count > 0)
ite8709_drop_hardware(dev);
case 5:
free_irq(dev->irq, dev);
case 4:
release_region(dev->io, 2);
case 3:
lirc_unregister_driver(dev->driver.minor);
case 2:
lirc_buffer_free(dev->driver.rbuf);
kfree(dev->driver.rbuf);
case 1:
kfree(dev);
case 0:
;
}
return errno;
}
static int __devinit ite8709_pnp_probe(struct pnp_dev *dev,
const struct pnp_device_id *dev_id)
{
struct lirc_driver *driver;
struct ite8709_device *ite8709_dev;
int ret;
/* Check resources validity */
if (!pnp_irq_valid(dev, 0))
return ite8709_cleanup(NULL, 0, -ENODEV, "invalid IRQ");
if (!pnp_port_valid(dev, 2))
return ite8709_cleanup(NULL, 0, -ENODEV, "invalid IO port");
/* Allocate memory for device struct */
ite8709_dev = kzalloc(sizeof(struct ite8709_device), GFP_KERNEL);
if (ite8709_dev == NULL)
return ite8709_cleanup(NULL, 0, -ENOMEM, "kzalloc failed");
pnp_set_drvdata(dev, ite8709_dev);
/* Initialize device struct */
ite8709_dev->use_count = 0;
ite8709_dev->irq = pnp_irq(dev, 0);
ite8709_dev->io = pnp_port_start(dev, 2);
ite8709_dev->hardware_lock =
__SPIN_LOCK_UNLOCKED(ite8709_dev->hardware_lock);
ite8709_dev->acc_pulse = 0;
ite8709_dev->acc_space = 0;
ite8709_dev->lastbit = 0;
do_gettimeofday(&ite8709_dev->last_tv);
tasklet_init(&ite8709_dev->tasklet, ite8709_rearm_irq,
(long) ite8709_dev);
ite8709_dev->force_rearm = 0;
ite8709_dev->rearmed = 0;
ite8709_dev->device_busy = 0;
/* Initialize driver struct */
driver = &ite8709_dev->driver;
strcpy(driver->name, LIRC_DRIVER_NAME);
driver->minor = -1;
driver->code_length = sizeof(int) * 8;
driver->sample_rate = 0;
driver->features = LIRC_CAN_REC_MODE2;
driver->data = ite8709_dev;
driver->add_to_buf = NULL;
driver->set_use_inc = ite8709_set_use_inc;
driver->set_use_dec = ite8709_set_use_dec;
driver->dev = &dev->dev;
driver->owner = THIS_MODULE;
/* Initialize LIRC buffer */
driver->rbuf = kmalloc(sizeof(struct lirc_buffer), GFP_KERNEL);
if (!driver->rbuf)
return ite8709_cleanup(ite8709_dev, 1, -ENOMEM,
"can't allocate lirc_buffer");
if (lirc_buffer_init(driver->rbuf, BUF_CHUNK_SIZE, BUF_SIZE))
return ite8709_cleanup(ite8709_dev, 1, -ENOMEM,
"lirc_buffer_init() failed");
/* Register LIRC driver */
ret = lirc_register_driver(driver);
if (ret < 0)
return ite8709_cleanup(ite8709_dev, 2, ret,
"lirc_register_driver() failed");
/* Reserve I/O port access */
if (!request_region(ite8709_dev->io, 2, LIRC_DRIVER_NAME))
return ite8709_cleanup(ite8709_dev, 3, -EBUSY,
"i/o port already in use");
/* Reserve IRQ line */
ret = request_irq(ite8709_dev->irq, ite8709_interrupt, 0,
LIRC_DRIVER_NAME, ite8709_dev);
if (ret < 0)
return ite8709_cleanup(ite8709_dev, 4, ret,
"IRQ already in use");
/* Initialize hardware */
ite8709_drop_hardware(ite8709_dev); /* Shutdown hw until first use */
printk(KERN_INFO LIRC_DRIVER_NAME ": device found : irq=%d io=0x%x\n",
ite8709_dev->irq, ite8709_dev->io);
return 0;
}
static void __devexit ite8709_pnp_remove(struct pnp_dev *dev)
{
struct ite8709_device *ite8709_dev;
ite8709_dev = pnp_get_drvdata(dev);
ite8709_cleanup(ite8709_dev, 6, 0, NULL);
printk(KERN_INFO LIRC_DRIVER_NAME ": device removed\n");
}
#ifdef CONFIG_PM
static int ite8709_pnp_suspend(struct pnp_dev *dev, pm_message_t state)
{
struct ite8709_device *ite8709_dev;
ite8709_dev = pnp_get_drvdata(dev);
if (ite8709_dev->use_count > 0)
ite8709_drop_hardware(ite8709_dev);
return 0;
}
static int ite8709_pnp_resume(struct pnp_dev *dev)
{
struct ite8709_device *ite8709_dev;
ite8709_dev = pnp_get_drvdata(dev);
if (ite8709_dev->use_count > 0)
ite8709_init_hardware(ite8709_dev);
return 0;
}
#else
#define ite8709_pnp_suspend NULL
#define ite8709_pnp_resume NULL
#endif
static const struct pnp_device_id pnp_dev_table[] = {
{"ITE8709", 0},
{}
};
MODULE_DEVICE_TABLE(pnp, pnp_dev_table);
static struct pnp_driver ite8709_pnp_driver = {
.name = LIRC_DRIVER_NAME,
.probe = ite8709_pnp_probe,
.remove = __devexit_p(ite8709_pnp_remove),
.suspend = ite8709_pnp_suspend,
.resume = ite8709_pnp_resume,
.id_table = pnp_dev_table,
};
static int __init ite8709_init_module(void)
{
return pnp_register_driver(&ite8709_pnp_driver);
}
module_init(ite8709_init_module);
static void __exit ite8709_cleanup_module(void)
{
pnp_unregister_driver(&ite8709_pnp_driver);
}
module_exit(ite8709_cleanup_module);
MODULE_DESCRIPTION("LIRC driver for ITE8709 CIR port");
MODULE_AUTHOR("Grégory Lardière");
MODULE_LICENSE("GPL");
module_param(debug, bool, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(debug, "Enable debugging messages");
