--- /dev/null
+/*
+ * 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;
+ unsigned long long acc_pulse;
+ unsigned long long 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,
+ unsigned long long 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");
projects / linux-beck.git / commitdiff