/*
	The all defines and part of code (such as cs461x_*) are 
	contributed from ALSA 0.5.8 sources. 
	See http://www.alsa-project.org/ for sources
	
	Tested on Linux 686 2.4.0-test9, ALSA 0.5.8a and CS4610
*/

#include <asm/io.h>

#include <linux/module.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/gameport.h>
#include <linux/slab.h>
#include <linux/pci.h>

MODULE_AUTHOR("Victor Krapivin <vik@belcaf.minsk.by>");

/*
	These options are experimental

#define COOKED_MODE
#define CS461X_FULL_MAP

*/

#ifndef PCI_VENDOR_ID_CIRRUS
#define PCI_VENDOR_ID_CIRRUS            0x1013
#endif
#ifndef PCI_DEVICE_ID_CIRRUS_4610
#define PCI_DEVICE_ID_CIRRUS_4610       0x6001
#endif
#ifndef PCI_DEVICE_ID_CIRRUS_4612
#define PCI_DEVICE_ID_CIRRUS_4612       0x6003
#endif
#ifndef PCI_DEVICE_ID_CIRRUS_4615
#define PCI_DEVICE_ID_CIRRUS_4615       0x6004
#endif

/* Registers */

#define BA0_JSPT                                0x00000480
#define BA0_JSCTL                               0x00000484
#define BA0_JSC1                                0x00000488
#define BA0_JSC2                                0x0000048C
#define BA0_JSIO                                0x000004A0

/* Bits for JSPT */

#define JSPT_CAX                                0x00000001
#define JSPT_CAY                                0x00000002
#define JSPT_CBX                                0x00000004
#define JSPT_CBY                                0x00000008
#define JSPT_BA1                                0x00000010
#define JSPT_BA2                                0x00000020
#define JSPT_BB1                                0x00000040
#define JSPT_BB2                                0x00000080

/* Bits for JSCTL */

#define JSCTL_SP_MASK                           0x00000003
#define JSCTL_SP_SLOW                           0x00000000
#define JSCTL_SP_MEDIUM_SLOW                    0x00000001
#define JSCTL_SP_MEDIUM_FAST                    0x00000002
#define JSCTL_SP_FAST                           0x00000003
#define JSCTL_ARE                               0x00000004

/* Data register pairs masks */

#define JSC1_Y1V_MASK                           0x0000FFFF
#define JSC1_X1V_MASK                           0xFFFF0000
#define JSC1_Y1V_SHIFT                          0
#define JSC1_X1V_SHIFT                          16
#define JSC2_Y2V_MASK                           0x0000FFFF
#define JSC2_X2V_MASK                           0xFFFF0000
#define JSC2_Y2V_SHIFT                          0
#define JSC2_X2V_SHIFT                          16

/* JS GPIO */

#define JSIO_DAX                                0x00000001
#define JSIO_DAY                                0x00000002
#define JSIO_DBX                                0x00000004
#define JSIO_DBY                                0x00000008
#define JSIO_AXOE                               0x00000010
#define JSIO_AYOE                               0x00000020
#define JSIO_BXOE                               0x00000040
#define JSIO_BYOE                               0x00000080

/* 
   The card initialization code is obfuscated; the module cs461x 
   need to be loaded after ALSA modules initialized and something
   played on the CS 4610 chip (see sources for details of CS4610
   initialization code from ALSA)
*/

/* Card specific definitions */

#define CS461X_BA0_SIZE         0x2000
#define CS461X_BA1_DATA0_SIZE   0x3000
#define CS461X_BA1_DATA1_SIZE   0x3800
#define CS461X_BA1_PRG_SIZE     0x7000
#define CS461X_BA1_REG_SIZE     0x0100

#define BA1_SP_DMEM0                            0x00000000
#define BA1_SP_DMEM1                            0x00010000
#define BA1_SP_PMEM                             0x00020000
#define BA1_SP_REG                              0x00030000

#define BA1_DWORD_SIZE          (13 * 1024 + 512)
#define BA1_MEMORY_COUNT        3

/* 
   Only one CS461x card is still suppoted; the code requires
   redesign to avoid this limitatuion.
*/

static unsigned long ba0_addr;
static unsigned int *ba0;

#ifdef CS461X_FULL_MAP
static unsigned long ba1_addr;
static union ba1_t {
        struct {
                unsigned int *data0;
                unsigned int *data1;
                unsigned int *pmem;
                unsigned int *reg;
        } name;
        unsigned int *idx[4];
} ba1;

static void cs461x_poke(unsigned long reg, unsigned int val)
{
        ba1.idx[(reg >> 16) & 3][(reg >> 2) & 0x3fff] = val;
}

static unsigned int cs461x_peek(unsigned long reg)
{
        return ba1.idx[(reg >> 16) & 3][(reg >> 2) & 0x3fff];
}

#endif

static void cs461x_pokeBA0(unsigned long reg, unsigned int val)
{
        ba0[reg >> 2] = val;
}

static unsigned int cs461x_peekBA0(unsigned long reg)
{
        return ba0[reg >> 2];
}

static int cs461x_free(struct pci_dev *pdev)
{
	struct gameport *port = (struct gameport *)pdev->driver_data;
	if(port){
	    gameport_unregister_port(port);
	    kfree(port);
	}    
	if (ba0) iounmap(ba0);
#ifdef CS461X_FULL_MAP
	if (ba1.name.data0) iounmap(ba1.name.data0);
	if (ba1.name.data1) iounmap(ba1.name.data1);
	if (ba1.name.pmem)  iounmap(ba1.name.pmem);
	if (ba1.name.reg)   iounmap(ba1.name.reg);
#endif
	return 0;
}

static void cs461x_gameport_trigger(struct gameport *gameport)
{
	cs461x_pokeBA0(BA0_JSPT, 0xFF);  //outb(gameport->io, 0xFF);
}

static unsigned char cs461x_gameport_read(struct gameport *gameport)
{
	return cs461x_peekBA0(BA0_JSPT); //inb(gameport->io);
}

static int cs461x_gameport_cooked_read(struct gameport *gameport, int *axes, int *buttons)
{
	unsigned js1, js2, jst;
	
	js1 = cs461x_peekBA0(BA0_JSC1);
	js2 = cs461x_peekBA0(BA0_JSC2);
	jst = cs461x_peekBA0(BA0_JSPT);
	
	*buttons = (~jst >> 4) & 0x0F; 
	
	axes[0] = ((js1 & JSC1_Y1V_MASK) >> JSC1_Y1V_SHIFT) & 0xFFFF;
	axes[1] = ((js1 & JSC1_X1V_MASK) >> JSC1_X1V_SHIFT) & 0xFFFF;
	axes[2] = ((js2 & JSC2_Y2V_MASK) >> JSC2_Y2V_SHIFT) & 0xFFFF;
	axes[3] = ((js2 & JSC2_X2V_MASK) >> JSC2_X2V_SHIFT) & 0xFFFF;

	for(jst=0;jst<4;++jst)
		if(axes[jst]==0xFFFF) axes[jst] = -1;
	return 0;
}

static int cs461x_gameport_open(struct gameport *gameport, int mode)
{
	switch (mode) {
#ifdef COOKED_MODE
	case GAMEPORT_MODE_COOKED:
		return 0;
#endif
	case GAMEPORT_MODE_RAW:
		return 0;
	default:
		return -1;
	}
	return 0;
}

static struct pci_device_id cs461x_pci_tbl[] __devinitdata = {
	{ PCI_VENDOR_ID_CIRRUS, 0x6001, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0 }, /* Cirrus CS4610 */
	{ PCI_VENDOR_ID_CIRRUS, 0x6003, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0 }, /* Cirrus CS4612 */
	{ PCI_VENDOR_ID_CIRRUS, 0x6005, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0 }, /* Cirrus CS4615 */
	{ 0, }
};
MODULE_DEVICE_TABLE(pci, cs461x_pci_tbl);

static int __devinit cs461x_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
{
	int rc;
	struct gameport* port;
	
	rc = pci_enable_device(pdev);
	if (rc) {
		printk(KERN_ERR "cs461x: Cannot enable PCI gameport (bus %d, devfn %d) error=%d\n",
			pdev->bus->number, pdev->devfn, rc);
		return rc;
	}

	ba0_addr = pci_resource_start(pdev, 0);
#ifdef CS461X_FULL_MAP
	ba1_addr = pci_resource_start(pdev, 1);
#endif
	if (ba0_addr == 0 || ba0_addr == ~0 
#ifdef CS461X_FULL_MAP
            || ba1_addr == 0 || ba1_addr == ~0
#endif
	    ) {
                printk(KERN_ERR "cs461x: wrong address - ba0 = 0x%lx\n", ba0_addr);
#ifdef CS461X_FULL_MAP
                printk(KERN_ERR "cs461x: wrong address - ba1 = 0x%lx\n", ba1_addr);
#endif
		cs461x_free(pdev);
                return -ENOMEM;
        }

	ba0 = ioremap(ba0_addr, CS461X_BA0_SIZE);
#ifdef CS461X_FULL_MAP
	ba1.name.data0 = ioremap(ba1_addr + BA1_SP_DMEM0, CS461X_BA1_DATA0_SIZE);
	ba1.name.data1 = ioremap(ba1_addr + BA1_SP_DMEM1, CS461X_BA1_DATA1_SIZE);
	ba1.name.pmem  = ioremap(ba1_addr + BA1_SP_PMEM, CS461X_BA1_PRG_SIZE);
	ba1.name.reg   = ioremap(ba1_addr + BA1_SP_REG, CS461X_BA1_REG_SIZE);

	if (ba0 == NULL || ba1.name.data0 == NULL ||
            ba1.name.data1 == NULL || ba1.name.pmem == NULL ||
            ba1.name.reg == NULL) {
		cs461x_free(pdev);
                return -ENOMEM;
        }
#else
	if (ba0 == NULL){
		cs461x_free(pdev);
		return -ENOMEM;
	}
#endif
	printk(KERN_INFO "CS461x PCI: %lx[%d]\n",
	    ba0_addr, CS461X_BA0_SIZE);
        
	if (!(port = kmalloc(sizeof(struct gameport), GFP_KERNEL))) {
		printk(KERN_ERR "Memory allocation failed.\n");
		cs461x_free(pdev);
		return -ENOMEM;
	}
	memset(port, 0, sizeof(struct gameport));

	port->io = -1;
	port->size = -1;
	pdev->driver_data = port;
	
	port->open = cs461x_gameport_open;
	port->read = cs461x_gameport_read;
	port->trigger = cs461x_gameport_trigger;
#ifdef COOKED_MODE
	port->cooked_read = cs461x_gameport_cooked_read;
#endif

	cs461x_pokeBA0(BA0_JSIO, 0xFF); // ?
	cs461x_pokeBA0(BA0_JSCTL, JSCTL_SP_MEDIUM_SLOW);

	gameport_register_port(port);

	printk(KERN_INFO "gameport%d: CS461x PCI", port->number);
	if (port->size > 1) printk(" size %d", port->size);
	printk(" speed %d kHz\n", port->speed);

	return 0;
}

static void __devexit cs461x_pci_remove(struct pci_dev *pdev)
{
	cs461x_free(pdev);
}
	
static struct pci_driver cs461x_pci_driver = {
        name:           "PCI Gameport",
        id_table:       cs461x_pci_tbl,
        probe:          cs461x_pci_probe,
        remove:         cs461x_pci_remove,
};

int __init js_cs461x_init(void)
{
        return pci_module_init(&cs461x_pci_driver);
}

void __exit js_cs461x_exit(void)
{
        pci_unregister_driver(&cs461x_pci_driver);
}

module_init(js_cs461x_init);
module_exit(js_cs461x_exit);

