#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/spi/spi.h>

int ask_2272_1527_pulse_duty_factor[4]={13,5,7,11};

struct spi_device *spi;

u16 word;
//unsigned char wordx[2] = "xy";
//unsigned char *word = (unsigned char *)wordx;

void
rfm12_ask_encode_tribit(int *code, int append, int byte, int cnt)
{
    int i;
    for (i=0;i<cnt;i++)
    {
        if (byte & (1<<(cnt-i-1))) {
            code[append+(i*2)]=ask_2272_1527_pulse_duty_factor[0];
            code[append+(i*2)+1]=ask_2272_1527_pulse_duty_factor[1];
        } else {
            code[append+(i*2)]=ask_2272_1527_pulse_duty_factor[2];
            code[append+(i*2)+1]=ask_2272_1527_pulse_duty_factor[3];
        }
    }
}

void
rfm12_ask_trigger(int level, int us)
{
    if (level)
    {
        word = 0x8200|(1<<5)|(1<<4)|(1<<3);
        spi_write(spi, (const u8 *)&word, 2); // 2. PwrMngt TX on
        for(;us>0;us--)
            udelay(1);
    }
    else
    {
        word = 0x8208;
        spi_write(spi, (const u8 *)&word, 2);                                           // 2. PwrMngt TX off
        for(;us>0;us--)
            udelay(1);
    }
}

void
rfm12_ask_2272_send(int *command, int delay, int cnt)
{
    int code[49];

    int i;
    printk(KERN_ALERT "encoding\n");
    for(i=0;i<3;i++)
    {
        rfm12_ask_encode_tribit(code, i*16, command[i], 8);
    }
    code[48]=7; //sync
//  rfm12_prologue ();
    word = 0x8200|(1<<5)|(1<<4)|(1<<3);
    printk(KERN_ALERT "??\n");
    spi_write(spi, (const u8 *)&word, 2);    // 2. PwrMngt TX on
    int ii;
    for(ii=cnt;ii>0;ii--)                            // Sequenz cnt send
    {
        int rfm12_trigger_level=0;
        int i;
        for(i=0;i<49;i++)
        {
        printk(KERN_ALERT "running trigger\n");
            rfm12_ask_trigger(rfm12_trigger_level^=1,code[i]*delay);
        }
        printk(KERN_ALERT "running trigger (2)\n");
        rfm12_ask_trigger(0,24*delay);
    }
    word = 0x8208;
    printk(KERN_ALERT "set <0x8208>\n");
    spi_write(spi, (const u8 *)&word, 2);                                               // 2. PwrMngt TX off
//  rfm12_epilogue ();
}

#define RFM12BAND(freq) (freq<800000?0x80D7:0x80E7)

static int __devinit rfm12_probe(struct spi_device *spi_)
{
    printk(KERN_ALERT "probing\n");
    spi = spi_;
    printk(KERN_ALERT "setting mode\n");
    spi->mode = SPI_MODE_0;
    printk(KERN_ALERT "setting word size\n");
    spi->bits_per_word = 16;
    printk(KERN_ALERT "setup spi device\n");
    spi_setup(spi);

    //word = 0x0000;
    //spi_write(spi, (const u8 *)&word, 2);

    word = 0x0000;
    printk(KERN_ALERT "get status\n");
    spi_write(spi, (const u8 *)&word, 2);
    spi_read(spi, (u8 *)&word, 2);
    printk(KERN_ALERT "got %x\n", word);

    word = 0xC0E0;
    printk(KERN_ALERT "set <1>\n");
    spi_write(spi, (const u8 *)&word, 2);       /* AVR CLK: 10MHz */
    word = RFM12BAND(433920);
    printk(KERN_ALERT "set <2>\n");
    spi_write(spi, (const u8 *)&word, 2);   /* Select BAND, Enable FIFO */
    word = 0xC2AB;
    printk(KERN_ALERT "set <3>\n");
    spi_write(spi, (const u8 *)&word, 2);       /* Data Filter: internal */
    word = 0xCA81;
    printk(KERN_ALERT "set <4>\n");
    spi_write(spi, (const u8 *)&word, 2);       /* Set FIFO mode */
    word = 0xE000;
    printk(KERN_ALERT "set <5>\n");
    spi_write(spi, (const u8 *)&word, 2);       /* disable wakeuptimer */
    word = 0xC800;
    printk(KERN_ALERT "set <6>\n");
    spi_write(spi, (const u8 *)&word, 2);       /* disable low duty cycle */
    word = 0xC4F7;
    printk(KERN_ALERT "set <7>\n");
    spi_write(spi, (const u8 *)&word, 2);       /* AFC settings: autotuning: -10kHz...+7,5kHz */

    int command[3];
    command[0] = 0;
    command[1] = 5;
    command[2] = 81;
    printk(KERN_ALERT "sending (0,5,81), 76, 10\n");
    rfm12_ask_2272_send(command, 76, 10);
    printk(KERN_ALERT "finished\n");

    return 0;
}

static struct spi_driver rfm12_driver = {
    .driver = {
        .name = "rfm12",
        .owner = THIS_MODULE,
    },
    .probe = rfm12_probe,
};

int init_module(void)
{
    printk(KERN_ALERT "init module\n");
    printk(KERN_ALERT "register spi driver\n");
    int res_spi_register_driver = spi_register_driver(&rfm12_driver);
    //int res_setup_sysfs = setup_sysfs();
    //return res_spi_register_driver | res_setup_sysfs;
    return res_spi_register_driver;
}

void cleanup_module(void)
{
    spi_unregister_driver(&rfm12_driver);
}

MODULE_LICENSE("GPL");