/*
 * Driver for the Cirrus PD6729 PCI-PCMCIA bridge.
 *
 * Based on the i82092.c driver.
 *
 * This software may be used and distributed according to the terms of
 * the GNU General Public License, incorporated herein by reference.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/workqueue.h>
#include <linux/interrupt.h>
#include <linux/device.h>
#include <linux/io.h>

#include <pcmcia/ss.h>


#include "pd6729.h"
#include "i82365.h"
#include "cirrus.h"

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Driver for the Cirrus PD6729 PCI-PCMCIA bridge");
MODULE_AUTHOR("Jun Komuro <komurojun-mbn@nifty.com>");

#define MAX_SOCKETS 2

/*
 * simple helper functions
 * External clock time, in nanoseconds.  120 ns = 8.33 MHz
 */
#define to_cycles(ns)   ((ns)/120)

#ifndef NO_IRQ
#define NO_IRQ  ((unsigned int)(0))
#endif

/*
 * PARAMETERS
 *  irq_mode=n
 *     Specifies the interrupt delivery mode.  The default (1) is to use PCI
 *     interrupts; a value of 0 selects ISA interrupts. This must be set for
 *     correct operation of PCI card readers.
 */

static int irq_mode = 1; /* 0 = ISA interrupt, 1 = PCI interrupt */

module_param(irq_mode, int, 0444);
MODULE_PARM_DESC(irq_mode,
                "interrupt delivery mode. 0 = ISA, 1 = PCI. default is 1");

static DEFINE_SPINLOCK(port_lock);

/* basic value read/write functions */

static unsigned char indirect_read(struct pd6729_socket *socket,
                                   unsigned short reg)
{
        unsigned long port;
        unsigned char val;
        unsigned long flags;

        spin_lock_irqsave(&port_lock, flags);
        reg += socket->number * 0x40;
        port = socket->io_base;
        outb(reg, port);
        val = inb(port + 1);
        spin_unlock_irqrestore(&port_lock, flags);

        return val;
}

static unsigned short indirect_read16(struct pd6729_socket *socket,
                                      unsigned short reg)
{
        unsigned long port;
        unsigned short tmp;
        unsigned long flags;

        spin_lock_irqsave(&port_lock, flags);
        reg  = reg + socket->number * 0x40;
        port = socket->io_base;
        outb(reg, port);
        tmp = inb(port + 1);
        reg++;
        outb(reg, port);
        tmp = tmp | (inb(port + 1) << 8);
        spin_unlock_irqrestore(&port_lock, flags);

        return tmp;
}

static void indirect_write(struct pd6729_socket *socket, unsigned short reg,
                           unsigned char value)
{
        unsigned long port;
        unsigned long flags;

        spin_lock_irqsave(&port_lock, flags);
        reg = reg + socket->number * 0x40;
        port = socket->io_base;
        outb(reg, port);
        outb(value, port + 1);
        spin_unlock_irqrestore(&port_lock, flags);
}

static void indirect_setbit(struct pd6729_socket *socket, unsigned short reg,
                            unsigned char mask)
{
        unsigned long port;
        unsigned char val;
        unsigned long flags;

        spin_lock_irqsave(&port_lock, flags);
        reg = reg + socket->number * 0x40;
        port = socket->io_base;
        outb(reg, port);
        val = inb(port + 1);
        val |= mask;
        outb(reg, port);
        outb(val, port + 1);
        spin_unlock_irqrestore(&port_lock, flags);
}

static void indirect_resetbit(struct pd6729_socket *socket, unsigned short reg,
                              unsigned char mask)
{
        unsigned long port;
        unsigned char val;
        unsigned long flags;

        spin_lock_irqsave(&port_lock, flags);
        reg = reg + socket->number * 0x40;
        port = socket->io_base;
        outb(reg, port);
        val = inb(port + 1);
        val &= ~mask;
        outb(reg, port);
        outb(val, port + 1);
        spin_unlock_irqrestore(&port_lock, flags);
}

static void indirect_write16(struct pd6729_socket *socket, unsigned short reg,
                             unsigned short value)
{
        unsigned long port;
        unsigned char val;
        unsigned long flags;

        spin_lock_irqsave(&port_lock, flags);
        reg = reg + socket->number * 0x40;
        port = socket->io_base;

        outb(reg, port);
        val = value & 255;
        outb(val, port + 1);

        reg++;

        outb(reg, port);
        val = value >> 8;
        outb(val, port + 1);
        spin_unlock_irqrestore(&port_lock, flags);
}

/* Interrupt handler functionality */

static irqreturn_t pd6729_interrupt(int irq, void *dev)
{
        struct pd6729_socket *socket = (struct pd6729_socket *)dev;
        int i;
        int loopcount = 0;
        int handled = 0;
        unsigned int events, active = 0;

        while (1) {
                loopcount++;
                if (loopcount > 20) {
                        printk(KERN_ERR "pd6729: infinite eventloop "
                               "in interrupt\n");
                        break;
                }

                active = 0;

                for (i = 0; i < MAX_SOCKETS; i++) {
                        unsigned int csc;

                        /* card status change register */
                        csc = indirect_read(&socket[i], I365_CSC);
                        if (csc == 0)  /* no events on this socket */
                                continue;

                        handled = 1;
                        events = 0;

                        if (csc & I365_CSC_DETECT) {
                                events |= SS_DETECT;
                                dev_vdbg(&socket[i].socket.dev,
                                        "Card detected in socket %i!\n", i);
                        }

                        if (indirect_read(&socket[i], I365_INTCTL)
                                                & I365_PC_IOCARD) {
                                /* For IO/CARDS, bit 0 means "read the card" */
                                events |= (csc & I365_CSC_STSCHG)
                                                ? SS_STSCHG : 0;
                        } else {
                                /* Check for battery/ready events */
                                events |= (csc & I365_CSC_BVD1)
                                                ? SS_BATDEAD : 0;
                                events |= (csc & I365_CSC_BVD2)
                                                ? SS_BATWARN : 0;
                                events |= (csc & I365_CSC_READY)
                                                ? SS_READY : 0;
                        }

                        if (events)
                                pcmcia_parse_events(&socket[i].socket, events);

                        active |= events;
                }

                if (active == 0) /* no more events to handle */
                        break;
        }
        return IRQ_RETVAL(handled);
}

/* socket functions */

static void pd6729_interrupt_wrapper(struct timer_list *t)
{
        struct pd6729_socket *socket = timer_container_of(socket, t,
                                                          poll_timer);

        pd6729_interrupt(0, (void *)socket);
        mod_timer(&socket->poll_timer, jiffies + HZ);
}

static int pd6729_get_status(struct pcmcia_socket *sock, u_int *value)
{
        struct pd6729_socket *socket
                        = container_of(sock, struct pd6729_socket, socket);
        unsigned int status;
        unsigned int data;
        struct pd6729_socket *t;

        /* Interface Status Register */
        status = indirect_read(socket, I365_STATUS);
        *value = 0;

        if ((status & I365_CS_DETECT) == I365_CS_DETECT)
                *value |= SS_DETECT;

        /*
         * IO cards have a different meaning of bits 0,1
         * Also notice the inverse-logic on the bits
         */
        if (indirect_read(socket, I365_INTCTL) & I365_PC_IOCARD) {
                /* IO card */
                if (!(status & I365_CS_STSCHG))
                        *value |= SS_STSCHG;
        } else {
                /* non I/O card */
                if (!(status & I365_CS_BVD1))
                        *value |= SS_BATDEAD;
                if (!(status & I365_CS_BVD2))
                        *value |= SS_BATWARN;
        }

        if (status & I365_CS_WRPROT)
                *value |= SS_WRPROT;    /* card is write protected */

        if (status & I365_CS_READY)
                *value |= SS_READY;     /* card is not busy */

        if (status & I365_CS_POWERON)
                *value |= SS_POWERON;   /* power is applied to the card */

        t = (socket->number) ? socket : socket + 1;
        indirect_write(t, PD67_EXT_INDEX, PD67_EXTERN_DATA);
        data = indirect_read16(t, PD67_EXT_DATA);
        *value |= (data & PD67_EXD_VS1(socket->number)) ? 0 : SS_3VCARD;

        return 0;
}


static int pd6729_set_socket(struct pcmcia_socket *sock, socket_state_t *state)
{
        struct pd6729_socket *socket
                        = container_of(sock, struct pd6729_socket, socket);
        unsigned char reg, data;

        /* First, set the global controller options */
        indirect_write(socket, I365_GBLCTL, 0x00);
        indirect_write(socket, I365_GENCTL, 0x00);

        /* Values for the IGENC register */
        socket->card_irq = state->io_irq;

        reg = 0;
        /* The reset bit has "inverse" logic */
        if (!(state->flags & SS_RESET))
                reg |= I365_PC_RESET;
        if (state->flags & SS_IOCARD)
                reg |= I365_PC_IOCARD;

        /* IGENC, Interrupt and General Control Register */
        indirect_write(socket, I365_INTCTL, reg);

        /* Power registers */

        reg = I365_PWR_NORESET; /* default: disable resetdrv on resume */

        if (state->flags & SS_PWR_AUTO) {
                dev_dbg(&sock->dev, "Auto power\n");
                reg |= I365_PWR_AUTO;   /* automatic power mngmnt */
        }
        if (state->flags & SS_OUTPUT_ENA) {
                dev_dbg(&sock->dev, "Power Enabled\n");
                reg |= I365_PWR_OUT;    /* enable power */
        }

        switch (state->Vcc) {
        case 0:
                break;
        case 33:
                dev_dbg(&sock->dev,
                        "setting voltage to Vcc to 3.3V on socket %i\n",
                        socket->number);
                reg |= I365_VCC_5V;
                indirect_setbit(socket, PD67_MISC_CTL_1, PD67_MC1_VCC_3V);
                break;
        case 50:
                dev_dbg(&sock->dev,
                        "setting voltage to Vcc to 5V on socket %i\n",
                        socket->number);
                reg |= I365_VCC_5V;
                indirect_resetbit(socket, PD67_MISC_CTL_1, PD67_MC1_VCC_3V);
                break;
        default:
                dev_dbg(&sock->dev,
                        "pd6729_set_socket called with invalid VCC power "
                        "value: %i\n", state->Vcc);
                return -EINVAL;
        }

        switch (state->Vpp) {
        case 0:
                dev_dbg(&sock->dev, "not setting Vpp on socket %i\n",
                        socket->number);
                break;
        case 33:
        case 50:
                dev_dbg(&sock->dev, "setting Vpp to Vcc for socket %i\n",
                        socket->number);
                reg |= I365_VPP1_5V;
                break;
        case 120:
                dev_dbg(&sock->dev, "setting Vpp to 12.0\n");
                reg |= I365_VPP1_12V;
                break;
        default:
                dev_dbg(&sock->dev, "pd6729: pd6729_set_socket called with "
                        "invalid VPP power value: %i\n", state->Vpp);
                return -EINVAL;
        }

        /* only write if changed */
        if (reg != indirect_read(socket, I365_POWER))
                indirect_write(socket, I365_POWER, reg);

        if (irq_mode == 1) {
                /* all interrupts are to be done as PCI interrupts */
                data = PD67_EC1_INV_MGMT_IRQ | PD67_EC1_INV_CARD_IRQ;
        } else
                data = 0;

        indirect_write(socket, PD67_EXT_INDEX, PD67_EXT_CTL_1);
        indirect_write(socket, PD67_EXT_DATA, data);

        /* Enable specific interrupt events */

        reg = 0x00;
        if (state->csc_mask & SS_DETECT)
                reg |= I365_CSC_DETECT;

        if (state->flags & SS_IOCARD) {
                if (state->csc_mask & SS_STSCHG)
                        reg |= I365_CSC_STSCHG;
        } else {
                if (state->csc_mask & SS_BATDEAD)
                        reg |= I365_CSC_BVD1;
                if (state->csc_mask & SS_BATWARN)
                        reg |= I365_CSC_BVD2;
                if (state->csc_mask & SS_READY)
                        reg |= I365_CSC_READY;
        }
        if (irq_mode == 1)
                reg |= 0x30;    /* management IRQ: PCI INTA# = "irq 3" */
        indirect_write(socket, I365_CSCINT, reg);

        reg = indirect_read(socket, I365_INTCTL);
        if (irq_mode == 1)
                reg |= 0x03;    /* card IRQ: PCI INTA# = "irq 3" */
        else
                reg |= socket->card_irq;
        indirect_write(socket, I365_INTCTL, reg);

        /* now clear the (probably bogus) pending stuff by doing a dummy read */
        (void)indirect_read(socket, I365_CSC);

        return 0;
}

static int pd6729_set_io_map(struct pcmcia_socket *sock,
                             struct pccard_io_map *io)
{
        struct pd6729_socket *socket
                        = container_of(sock, struct pd6729_socket, socket);
        unsigned char map, ioctl;

        map = io->map;

        /* Check error conditions */
        if (map > 1) {
                dev_dbg(&sock->dev, "pd6729_set_io_map with invalid map\n");
                return -EINVAL;
        }

        /* Turn off the window before changing anything */
        if (indirect_read(socket, I365_ADDRWIN) & I365_ENA_IO(map))
                indirect_resetbit(socket, I365_ADDRWIN, I365_ENA_IO(map));

        /* dev_dbg(&sock->dev, "set_io_map: Setting range to %x - %x\n",
           io->start, io->stop);*/

        /* write the new values */
        indirect_write16(socket, I365_IO(map)+I365_W_START, io->start);
        indirect_write16(socket, I365_IO(map)+I365_W_STOP, io->stop);

        ioctl = indirect_read(socket, I365_IOCTL) & ~I365_IOCTL_MASK(map);

        if (io->flags & MAP_0WS)
                ioctl |= I365_IOCTL_0WS(map);
        if (io->flags & MAP_16BIT)
                ioctl |= I365_IOCTL_16BIT(map);
        if (io->flags & MAP_AUTOSZ)
                ioctl |= I365_IOCTL_IOCS16(map);

        indirect_write(socket, I365_IOCTL, ioctl);

        /* Turn the window back on if needed */
        if (io->flags & MAP_ACTIVE)
                indirect_setbit(socket, I365_ADDRWIN, I365_ENA_IO(map));

        return 0;
}

static int pd6729_set_mem_map(struct pcmcia_socket *sock,
                              struct pccard_mem_map *mem)
{
        struct pd6729_socket *socket
                         = container_of(sock, struct pd6729_socket, socket);
        unsigned short base, i;
        unsigned char map;

        map = mem->map;
        if (map > 4) {
                dev_warn(&sock->dev, "invalid map requested\n");
                return -EINVAL;
        }

        if ((mem->res->start > mem->res->end) || (mem->speed > 1000)) {
                dev_warn(&sock->dev, "invalid invalid address / speed\n");
                return -EINVAL;
        }

        /* Turn off the window before changing anything */
        if (indirect_read(socket, I365_ADDRWIN) & I365_ENA_MEM(map))
                indirect_resetbit(socket, I365_ADDRWIN, I365_ENA_MEM(map));

        /* write the start address */
        base = I365_MEM(map);
        i = (mem->res->start >> 12) & 0x0fff;
        if (mem->flags & MAP_16BIT)
                i |= I365_MEM_16BIT;
        if (mem->flags & MAP_0WS)
                i |= I365_MEM_0WS;
        indirect_write16(socket, base + I365_W_START, i);

        /* write the stop address */

        i = (mem->res->end >> 12) & 0x0fff;
        switch (to_cycles(mem->speed)) {
        case 0:
                break;
        case 1:
                i |= I365_MEM_WS0;
                break;
        case 2:
                i |= I365_MEM_WS1;
                break;
        default:
                i |= I365_MEM_WS1 | I365_MEM_WS0;
                break;
        }

        indirect_write16(socket, base + I365_W_STOP, i);

        /* Take care of high byte */
        indirect_write(socket, PD67_EXT_INDEX, PD67_MEM_PAGE(map));
        indirect_write(socket, PD67_EXT_DATA, mem->res->start >> 24);

        /* card start */

        i = ((mem->card_start - mem->res->start) >> 12) & 0x3fff;
        if (mem->flags & MAP_WRPROT)
                i |= I365_MEM_WRPROT;
        if (mem->flags & MAP_ATTRIB) {
                /* dev_dbg(&sock->dev, "requesting attribute memory for "
                   "socket %i\n", socket->number);*/
                i |= I365_MEM_REG;
        } else {
                /* dev_dbg(&sock->dev, "requesting normal memory for "
                   "socket %i\n", socket->number);*/
        }
        indirect_write16(socket, base + I365_W_OFF, i);

        /* Enable the window if necessary */
        if (mem->flags & MAP_ACTIVE)
                indirect_setbit(socket, I365_ADDRWIN, I365_ENA_MEM(map));

        return 0;
}

static int pd6729_init(struct pcmcia_socket *sock)
{
        int i;
        struct resource res = { .end = 0x0fff };
        pccard_io_map io = { 0, 0, 0, 0, 1 };
        pccard_mem_map mem = { .res = &res, };

        pd6729_set_socket(sock, &dead_socket);
        for (i = 0; i < 2; i++) {
                io.map = i;
                pd6729_set_io_map(sock, &io);
        }
        for (i = 0; i < 5; i++) {
                mem.map = i;
                pd6729_set_mem_map(sock, &mem);
        }

        return 0;
}


/* the pccard structure and its functions */
static struct pccard_operations pd6729_operations = {
        .init                   = pd6729_init,
        .get_status             = pd6729_get_status,
        .set_socket             = pd6729_set_socket,
        .set_io_map             = pd6729_set_io_map,
        .set_mem_map            = pd6729_set_mem_map,
};

static irqreturn_t pd6729_test(int irq, void *dev)
{
        pr_devel("-> hit on irq %d\n", irq);
        return IRQ_HANDLED;
}

static int pd6729_check_irq(int irq)
{
        int ret;

        ret = request_irq(irq, pd6729_test, IRQF_PROBE_SHARED, "x",
                          pd6729_test);
        if (ret)
                return -1;

        free_irq(irq, pd6729_test);
        return 0;
}

static u_int pd6729_isa_scan(void)
{
        u_int mask0, mask = 0;
        int i;

        if (irq_mode == 1) {
                printk(KERN_INFO "pd6729: PCI card interrupts, "
                       "PCI status changes\n");
                return 0;
        }

        mask0 = PD67_MASK;

        /* just find interrupts that aren't in use */
        for (i = 0; i < 16; i++)
                if ((mask0 & (1 << i)) && (pd6729_check_irq(i) == 0))
                        mask |= (1 << i);

        printk(KERN_INFO "pd6729: ISA irqs = ");
        for (i = 0; i < 16; i++)
                if (mask & (1<<i))
                        printk("%s%d", ((mask & ((1<<i)-1)) ? "," : ""), i);

        if (mask == 0)
                printk("none!");
        else
                printk("  polling status changes.\n");

        return mask;
}

static int pd6729_pci_probe(struct pci_dev *dev,
                                      const struct pci_device_id *id)
{
        int i, j, ret;
        u_int mask;
        char configbyte;
        struct pd6729_socket *socket;

        socket = kzalloc_objs(struct pd6729_socket, MAX_SOCKETS);
        if (!socket) {
                dev_warn(&dev->dev, "failed to kzalloc socket.\n");
                return -ENOMEM;
        }

        ret = pci_enable_device(dev);
        if (ret) {
                dev_warn(&dev->dev, "failed to enable pci_device.\n");
                goto err_out_free_mem;
        }

        if (!pci_resource_start(dev, 0)) {
                dev_warn(&dev->dev, "refusing to load the driver as the "
                        "io_base is NULL.\n");
                ret = -ENOMEM;
                goto err_out_disable;
        }

        dev_info(&dev->dev, "Cirrus PD6729 PCI to PCMCIA Bridge at 0x%llx "
                "on irq %d\n",
                (unsigned long long)pci_resource_start(dev, 0), dev->irq);
        /*
         * Since we have no memory BARs some firmware may not
         * have had PCI_COMMAND_MEMORY enabled, yet the device needs it.
         */
        pci_read_config_byte(dev, PCI_COMMAND, &configbyte);
        if (!(configbyte & PCI_COMMAND_MEMORY)) {
                dev_dbg(&dev->dev, "pd6729: Enabling PCI_COMMAND_MEMORY.\n");
                configbyte |= PCI_COMMAND_MEMORY;
                pci_write_config_byte(dev, PCI_COMMAND, configbyte);
        }

        ret = pci_request_regions(dev, "pd6729");
        if (ret) {
                dev_warn(&dev->dev, "pci request region failed.\n");
                goto err_out_disable;
        }

        if (dev->irq == NO_IRQ)
                irq_mode = 0;   /* fall back to ISA interrupt mode */

        mask = pd6729_isa_scan();
        if (irq_mode == 0 && mask == 0) {
                dev_warn(&dev->dev, "no ISA interrupt is available.\n");
                ret = -ENODEV;
                goto err_out_free_res;
        }

        for (i = 0; i < MAX_SOCKETS; i++) {
                socket[i].io_base = pci_resource_start(dev, 0);
                socket[i].socket.features |= SS_CAP_PAGE_REGS | SS_CAP_PCCARD;
                socket[i].socket.map_size = 0x1000;
                socket[i].socket.irq_mask = mask;
                socket[i].socket.pci_irq  = dev->irq;
                socket[i].socket.cb_dev = dev;
                socket[i].socket.owner = THIS_MODULE;

                socket[i].number = i;

                socket[i].socket.ops = &pd6729_operations;
                socket[i].socket.resource_ops = &pccard_nonstatic_ops;
                socket[i].socket.dev.parent = &dev->dev;
                socket[i].socket.driver_data = &socket[i];
        }

        pci_set_drvdata(dev, socket);
        if (irq_mode == 1) {
                /* Register the interrupt handler */
                ret = request_irq(dev->irq, pd6729_interrupt, IRQF_SHARED,
                                  "pd6729", socket);
                if (ret) {
                        dev_err(&dev->dev, "Failed to register irq %d\n",
                                dev->irq);
                        goto err_out_free_res;
                }
        } else {
                /* poll Card status change */
                timer_setup(&socket->poll_timer, pd6729_interrupt_wrapper, 0);
                mod_timer(&socket->poll_timer, jiffies + HZ);
        }

        for (i = 0; i < MAX_SOCKETS; i++) {
                ret = pcmcia_register_socket(&socket[i].socket);
                if (ret) {
                        dev_warn(&dev->dev, "pcmcia_register_socket failed.\n");
                        for (j = 0; j < i ; j++)
                                pcmcia_unregister_socket(&socket[j].socket);
                        goto err_out_free_res2;
                }
        }

        return 0;

err_out_free_res2:
        if (irq_mode == 1)
                free_irq(dev->irq, socket);
        else
                timer_shutdown_sync(&socket->poll_timer);
err_out_free_res:
        pci_release_regions(dev);
err_out_disable:
        pci_disable_device(dev);

err_out_free_mem:
        kfree(socket);
        return ret;
}

static void pd6729_pci_remove(struct pci_dev *dev)
{
        int i;
        struct pd6729_socket *socket = pci_get_drvdata(dev);

        for (i = 0; i < MAX_SOCKETS; i++) {
                /* Turn off all interrupt sources */
                indirect_write(&socket[i], I365_CSCINT, 0);
                indirect_write(&socket[i], I365_INTCTL, 0);

                pcmcia_unregister_socket(&socket[i].socket);
        }

        if (irq_mode == 1)
                free_irq(dev->irq, socket);
        else
                timer_shutdown_sync(&socket->poll_timer);
        pci_release_regions(dev);
        pci_disable_device(dev);

        kfree(socket);
}

static const struct pci_device_id pd6729_pci_ids[] = {
        { PCI_DEVICE(PCI_VENDOR_ID_CIRRUS, PCI_DEVICE_ID_CIRRUS_6729) },
        { }
};
MODULE_DEVICE_TABLE(pci, pd6729_pci_ids);

static struct pci_driver pd6729_pci_driver = {
        .name           = "pd6729",
        .id_table       = pd6729_pci_ids,
        .probe          = pd6729_pci_probe,
        .remove         = pd6729_pci_remove,
};

module_pci_driver(pd6729_pci_driver);