lirc_bt829.c

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/*
 * Remote control driver for the TV-card based on bt829
 *
 *  by Leonid Froenchenko <[email protected]>
 *
 *  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/kernel.h>
#include <linux/module.h>
#include <linux/threads.h>
#include <linux/sched.h>
#include <linux/ioport.h>
#include <linux/pci.h>
#include <linux/delay.h>

#include <media/lirc_dev.h>

static int poll_main(void);
static int atir_init_start(void);

static void write_index(unsigned char index, unsigned int value);
static unsigned int read_index(unsigned char index);

static void do_i2c_start(void);
static void do_i2c_stop(void);

static void seems_wr_byte(unsigned char al);
static unsigned char seems_rd_byte(void);

static unsigned int read_index(unsigned char al);
static void write_index(unsigned char ah, unsigned int edx);

static void cycle_delay(int cycle);

static void do_set_bits(unsigned char bl);
static unsigned char do_get_bits(void);

#define DATA_PCI_OFF 0x7FFC00
#define WAIT_CYCLE   20

#define DRIVER_NAME "lirc_bt829"

static bool debug;
#define dprintk(fmt, args...)                        \
    do {                                 \
        if (debug)                       \
            printk(KERN_DEBUG DRIVER_NAME ": "fmt, ## args); \
    } while (0)

static int atir_minor;
static unsigned long pci_addr_phys;
static unsigned char *pci_addr_lin;

static struct lirc_driver atir_driver;

static struct pci_dev *do_pci_probe(void)
{
    struct pci_dev *my_dev;
    my_dev = pci_get_device(PCI_VENDOR_ID_ATI,
                PCI_DEVICE_ID_ATI_264VT, NULL);
    if (my_dev) {
        printk(KERN_ERR DRIVER_NAME ": Using device: %s\n",
               pci_name(my_dev));
        pci_addr_phys = 0;
        if (my_dev->resource[0].flags & IORESOURCE_MEM) {
            pci_addr_phys = my_dev->resource[0].start;
            printk(KERN_INFO DRIVER_NAME ": memory at 0x%08X\n",
                   (unsigned int)pci_addr_phys);
        }
        if (pci_addr_phys == 0) {
            printk(KERN_ERR DRIVER_NAME ": no memory resource ?\n");
            return NULL;
        }
    } else {
        printk(KERN_ERR DRIVER_NAME ": pci_probe failed\n");
        return NULL;
    }
    return my_dev;
}

static int atir_add_to_buf(void *data, struct lirc_buffer *buf)
{
    unsigned char key;
    int status;
    status = poll_main();
    key = (status >> 8) & 0xFF;
    if (status & 0xFF) {
        dprintk("reading key %02X\n", key);
        lirc_buffer_write(buf, &key);
        return 0;
    }
    return -ENODATA;
}

static int atir_set_use_inc(void *data)
{
    dprintk("driver is opened\n");
    return 0;
}

static void atir_set_use_dec(void *data)
{
    dprintk("driver is closed\n");
}

int init_module(void)
{
    struct pci_dev *pdev;

    pdev = do_pci_probe();
    if (pdev == NULL)
        return -ENODEV;

    if (!atir_init_start())
        return -ENODEV;

    strcpy(atir_driver.name, "ATIR");
    atir_driver.minor       = -1;
    atir_driver.code_length = 8;
    atir_driver.sample_rate = 10;
    atir_driver.data        = 0;
    atir_driver.add_to_buf  = atir_add_to_buf;
    atir_driver.set_use_inc = atir_set_use_inc;
    atir_driver.set_use_dec = atir_set_use_dec;
    atir_driver.dev         = &pdev->dev;
    atir_driver.owner       = THIS_MODULE;

    atir_minor = lirc_register_driver(&atir_driver);
    if (atir_minor < 0) {
        printk(KERN_ERR DRIVER_NAME ": failed to register driver!\n");
        return atir_minor;
    }
    dprintk("driver is registered on minor %d\n", atir_minor);

    return 0;
}


void cleanup_module(void)
{
    lirc_unregister_driver(atir_minor);
}


static int atir_init_start(void)
{
    pci_addr_lin = ioremap(pci_addr_phys + DATA_PCI_OFF, 0x400);
    if (pci_addr_lin == 0) {
        printk(KERN_INFO DRIVER_NAME ": pci mem must be mapped\n");
        return 0;
    }
    return 1;
}

static void cycle_delay(int cycle)
{
    udelay(WAIT_CYCLE*cycle);
}


static int poll_main(void)
{
    unsigned char status_high, status_low;

    do_i2c_start();

    seems_wr_byte(0xAA);
    seems_wr_byte(0x01);

    do_i2c_start();

    seems_wr_byte(0xAB);

    status_low = seems_rd_byte();
    status_high = seems_rd_byte();

    do_i2c_stop();

    return (status_high << 8) | status_low;
}

static void do_i2c_start(void)
{
    do_set_bits(3);
    cycle_delay(4);

    do_set_bits(1);
    cycle_delay(7);

    do_set_bits(0);
    cycle_delay(2);
}

static void do_i2c_stop(void)
{
    unsigned char bits;
    bits =  do_get_bits() & 0xFD;
    do_set_bits(bits);
    cycle_delay(1);

    bits |= 1;
    do_set_bits(bits);
    cycle_delay(2);

    bits |= 2;
    do_set_bits(bits);
    bits = 3;
    do_set_bits(bits);
    cycle_delay(2);
}

static void seems_wr_byte(unsigned char value)
{
    int i;
    unsigned char reg;

    reg = do_get_bits();
    for (i = 0; i < 8; i++) {
        if (value & 0x80)
            reg |= 0x02;
        else
            reg &= 0xFD;

        do_set_bits(reg);
        cycle_delay(1);

        reg |= 1;
        do_set_bits(reg);
        cycle_delay(1);

        reg &= 0xFE;
        do_set_bits(reg);
        cycle_delay(1);
        value <<= 1;
    }
    cycle_delay(2);

    reg |= 2;
    do_set_bits(reg);

    reg |= 1;
    do_set_bits(reg);

    cycle_delay(1);
    do_get_bits();

    reg &= 0xFE;
    do_set_bits(reg);
    cycle_delay(3);
}

static unsigned char seems_rd_byte(void)
{
    int i;
    int rd_byte;
    unsigned char bits_2, bits_1;

    bits_1 = do_get_bits() | 2;
    do_set_bits(bits_1);

    rd_byte = 0;
    for (i = 0; i < 8; i++) {
        bits_1 &= 0xFE;
        do_set_bits(bits_1);
        cycle_delay(2);

        bits_1 |= 1;
        do_set_bits(bits_1);
        cycle_delay(1);

        bits_2 = do_get_bits();
        if (bits_2 & 2)
            rd_byte |= 1;

        rd_byte <<= 1;
    }

    bits_1 = 0;
    if (bits_2 == 0)
        bits_1 |= 2;

    do_set_bits(bits_1);
    cycle_delay(2);

    bits_1 |= 1;
    do_set_bits(bits_1);
    cycle_delay(3);

    bits_1 &= 0xFE;
    do_set_bits(bits_1);
    cycle_delay(2);

    rd_byte >>= 1;
    rd_byte &= 0xFF;
    return rd_byte;
}

static void do_set_bits(unsigned char new_bits)
{
    int reg_val;
    reg_val = read_index(0x34);
    if (new_bits & 2) {
        reg_val &= 0xFFFFFFDF;
        reg_val |= 1;
    } else {
        reg_val &= 0xFFFFFFFE;
        reg_val |= 0x20;
    }
    reg_val |= 0x10;
    write_index(0x34, reg_val);

    reg_val = read_index(0x31);
    if (new_bits & 1)
        reg_val |= 0x1000000;
    else
        reg_val &= 0xFEFFFFFF;

    reg_val |= 0x8000000;
    write_index(0x31, reg_val);
}

static unsigned char do_get_bits(void)
{
    unsigned char bits;
    int reg_val;

    reg_val = read_index(0x34);
    reg_val |= 0x10;
    reg_val &= 0xFFFFFFDF;
    write_index(0x34, reg_val);

    reg_val = read_index(0x34);
    bits = 0;
    if (reg_val & 8)
        bits |= 2;
    else
        bits &= 0xFD;

    reg_val = read_index(0x31);
    if (reg_val & 0x1000000)
        bits |= 1;
    else
        bits &= 0xFE;

    return bits;
}

static unsigned int read_index(unsigned char index)
{
    unsigned char *addr;
    unsigned int value;
    /*  addr = pci_addr_lin + DATA_PCI_OFF + ((index & 0xFF) << 2); */
    addr = pci_addr_lin + ((index & 0xFF) << 2);
    value = readl(addr);
    return value;
}

static void write_index(unsigned char index, unsigned int reg_val)
{
    unsigned char *addr;
    addr = pci_addr_lin + ((index & 0xFF) << 2);
    writel(reg_val, addr);
}

MODULE_AUTHOR("Froenchenko Leonid");
MODULE_DESCRIPTION("IR remote driver for bt829 based TV cards");
MODULE_LICENSE("GPL");

module_param(debug, bool, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(debug, "Debug enabled or not");