/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 2008 Maxime Bizon <mbizon@freebox.fr>
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/ioport.h>
#include <linux/timer.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/pci.h>
#include <linux/gpio.h>

#include <bcm63xx_regs.h>
#include <bcm63xx_io.h>
#include "bcm63xx_pcmcia.h"

#define PFX     "bcm63xx_pcmcia: "

#ifdef CONFIG_CARDBUS
/* if cardbus is used, platform device needs reference to actual pci
 * device */
static struct pci_dev *bcm63xx_cb_dev;
#endif

/*
 * read/write helper for pcmcia regs
 */
static inline u32 pcmcia_readl(struct bcm63xx_pcmcia_socket *skt, u32 off)
{
        return bcm_readl(skt->base + off);
}

static inline void pcmcia_writel(struct bcm63xx_pcmcia_socket *skt,
                                 u32 val, u32 off)
{
        bcm_writel(val, skt->base + off);
}

/*
 * This callback should (re-)initialise the socket, turn on status
 * interrupts and PCMCIA bus, and wait for power to stabilise so that
 * the card status signals report correctly.
 *
 * Hardware cannot do that.
 */
static int bcm63xx_pcmcia_sock_init(struct pcmcia_socket *sock)
{
        return 0;
}

/*
 * This callback should remove power on the socket, disable IRQs from
 * the card, turn off status interrupts, and disable the PCMCIA bus.
 *
 * Hardware cannot do that.
 */
static int bcm63xx_pcmcia_suspend(struct pcmcia_socket *sock)
{
        return 0;
}

/*
 * Implements the set_socket() operation for the in-kernel PCMCIA
 * service (formerly SS_SetSocket in Card Services). We more or
 * less punt all of this work and let the kernel handle the details
 * of power configuration, reset, &c. We also record the value of
 * `state' in order to regurgitate it to the PCMCIA core later.
 */
static int bcm63xx_pcmcia_set_socket(struct pcmcia_socket *sock,
                                     socket_state_t *state)
{
        struct bcm63xx_pcmcia_socket *skt;
        unsigned long flags;
        u32 val;

        skt = sock->driver_data;

        spin_lock_irqsave(&skt->lock, flags);

        /* note: hardware cannot control socket power, so we will
         * always report SS_POWERON */

        /* apply socket reset */
        val = pcmcia_readl(skt, PCMCIA_C1_REG);
        if (state->flags & SS_RESET)
                val |= PCMCIA_C1_RESET_MASK;
        else
                val &= ~PCMCIA_C1_RESET_MASK;

        /* reverse reset logic for cardbus card */
        if (skt->card_detected && (skt->card_type & CARD_CARDBUS))
                val ^= PCMCIA_C1_RESET_MASK;

        pcmcia_writel(skt, val, PCMCIA_C1_REG);

        /* keep requested state for event reporting */
        skt->requested_state = *state;

        spin_unlock_irqrestore(&skt->lock, flags);

        return 0;
}

/*
 * identity cardtype from VS[12] input, CD[12] input while only VS2 is
 * floating, and CD[12] input while only VS1 is floating
 */
enum {
        IN_VS1 = (1 << 0),
        IN_VS2 = (1 << 1),
        IN_CD1_VS2H = (1 << 2),
        IN_CD2_VS2H = (1 << 3),
        IN_CD1_VS1H = (1 << 4),
        IN_CD2_VS1H = (1 << 5),
};

static const u8 vscd_to_cardtype[] = {

        /* VS1 float, VS2 float */
        [IN_VS1 | IN_VS2] = (CARD_PCCARD | CARD_5V),

        /* VS1 grounded, VS2 float */
        [IN_VS2] = (CARD_PCCARD | CARD_5V | CARD_3V),

        /* VS1 grounded, VS2 grounded */
        [0] = (CARD_PCCARD | CARD_5V | CARD_3V | CARD_XV),

        /* VS1 tied to CD1, VS2 float */
        [IN_VS1 | IN_VS2 | IN_CD1_VS1H] = (CARD_CARDBUS | CARD_3V),

        /* VS1 grounded, VS2 tied to CD2 */
        [IN_VS2 | IN_CD2_VS2H] = (CARD_CARDBUS | CARD_3V | CARD_XV),

        /* VS1 tied to CD2, VS2 grounded */
        [IN_VS1 | IN_CD2_VS1H] = (CARD_CARDBUS | CARD_3V | CARD_XV | CARD_YV),

        /* VS1 float, VS2 grounded */
        [IN_VS1] = (CARD_PCCARD | CARD_XV),

        /* VS1 float, VS2 tied to CD2 */
        [IN_VS1 | IN_VS2 | IN_CD2_VS2H] = (CARD_CARDBUS | CARD_3V),

        /* VS1 float, VS2 tied to CD1 */
        [IN_VS1 | IN_VS2 | IN_CD1_VS2H] = (CARD_CARDBUS | CARD_XV | CARD_YV),

        /* VS1 tied to CD2, VS2 float */
        [IN_VS1 | IN_VS2 | IN_CD2_VS1H] = (CARD_CARDBUS | CARD_YV),

        /* VS2 grounded, VS1 is tied to CD1, CD2 is grounded */
        [IN_VS1 | IN_CD1_VS1H] = 0, /* ignore cardbay */
};

/*
 * poll hardware to check card insertion status
 */
static unsigned int __get_socket_status(struct bcm63xx_pcmcia_socket *skt)
{
        unsigned int stat;
        u32 val;

        stat = 0;

        /* check CD for card presence */
        val = pcmcia_readl(skt, PCMCIA_C1_REG);

        if (!(val & PCMCIA_C1_CD1_MASK) && !(val & PCMCIA_C1_CD2_MASK))
                stat |= SS_DETECT;

        /* if new insertion, detect cardtype */
        if ((stat & SS_DETECT) && !skt->card_detected) {
                unsigned int stat = 0;

                /* float VS1, float VS2 */
                val |= PCMCIA_C1_VS1OE_MASK;
                val |= PCMCIA_C1_VS2OE_MASK;
                pcmcia_writel(skt, val, PCMCIA_C1_REG);

                /* wait for output to stabilize and read VS[12] */
                udelay(10);
                val = pcmcia_readl(skt, PCMCIA_C1_REG);
                stat |= (val & PCMCIA_C1_VS1_MASK) ? IN_VS1 : 0;
                stat |= (val & PCMCIA_C1_VS2_MASK) ? IN_VS2 : 0;

                /* drive VS1 low, float VS2 */
                val &= ~PCMCIA_C1_VS1OE_MASK;
                val |= PCMCIA_C1_VS2OE_MASK;
                pcmcia_writel(skt, val, PCMCIA_C1_REG);

                /* wait for output to stabilize and read CD[12] */
                udelay(10);
                val = pcmcia_readl(skt, PCMCIA_C1_REG);
                stat |= (val & PCMCIA_C1_CD1_MASK) ? IN_CD1_VS2H : 0;
                stat |= (val & PCMCIA_C1_CD2_MASK) ? IN_CD2_VS2H : 0;

                /* float VS1, drive VS2 low */
                val |= PCMCIA_C1_VS1OE_MASK;
                val &= ~PCMCIA_C1_VS2OE_MASK;
                pcmcia_writel(skt, val, PCMCIA_C1_REG);

                /* wait for output to stabilize and read CD[12] */
                udelay(10);
                val = pcmcia_readl(skt, PCMCIA_C1_REG);
                stat |= (val & PCMCIA_C1_CD1_MASK) ? IN_CD1_VS1H : 0;
                stat |= (val & PCMCIA_C1_CD2_MASK) ? IN_CD2_VS1H : 0;

                /* guess cardtype from all this */
                skt->card_type = vscd_to_cardtype[stat];
                if (!skt->card_type)
                        dev_err(&skt->socket.dev, "unsupported card type\n");

                /* drive both VS pin to 0 again */
                val &= ~(PCMCIA_C1_VS1OE_MASK | PCMCIA_C1_VS2OE_MASK);

                /* enable correct logic */
                val &= ~(PCMCIA_C1_EN_PCMCIA_MASK | PCMCIA_C1_EN_CARDBUS_MASK);
                if (skt->card_type & CARD_PCCARD)
                        val |= PCMCIA_C1_EN_PCMCIA_MASK;
                else
                        val |= PCMCIA_C1_EN_CARDBUS_MASK;

                pcmcia_writel(skt, val, PCMCIA_C1_REG);
        }
        skt->card_detected = (stat & SS_DETECT) ? 1 : 0;

        /* report card type/voltage */
        if (skt->card_type & CARD_CARDBUS)
                stat |= SS_CARDBUS;
        if (skt->card_type & CARD_3V)
                stat |= SS_3VCARD;
        if (skt->card_type & CARD_XV)
                stat |= SS_XVCARD;
        stat |= SS_POWERON;

        if (gpio_get_value(skt->pd->ready_gpio))
                stat |= SS_READY;

        return stat;
}

/*
 * core request to get current socket status
 */
static int bcm63xx_pcmcia_get_status(struct pcmcia_socket *sock,
                                     unsigned int *status)
{
        struct bcm63xx_pcmcia_socket *skt;

        skt = sock->driver_data;

        spin_lock_bh(&skt->lock);
        *status = __get_socket_status(skt);
        spin_unlock_bh(&skt->lock);

        return 0;
}

/*
 * socket polling timer callback
 */
static void bcm63xx_pcmcia_poll(struct timer_list *t)
{
        struct bcm63xx_pcmcia_socket *skt;
        unsigned int stat, events;

        skt = from_timer(skt, t, timer);

        spin_lock_bh(&skt->lock);

        stat = __get_socket_status(skt);

        /* keep only changed bits, and mask with required one from the
         * core */
        events = (stat ^ skt->old_status) & skt->requested_state.csc_mask;
        skt->old_status = stat;
        spin_unlock_bh(&skt->lock);

        if (events)
                pcmcia_parse_events(&skt->socket, events);

        mod_timer(&skt->timer,
                  jiffies + msecs_to_jiffies(BCM63XX_PCMCIA_POLL_RATE));
}

static int bcm63xx_pcmcia_set_io_map(struct pcmcia_socket *sock,
                                     struct pccard_io_map *map)
{
        /* this doesn't seem to be called by pcmcia layer if static
         * mapping is used */
        return 0;
}

static int bcm63xx_pcmcia_set_mem_map(struct pcmcia_socket *sock,
                                      struct pccard_mem_map *map)
{
        struct bcm63xx_pcmcia_socket *skt;
        struct resource *res;

        skt = sock->driver_data;
        if (map->flags & MAP_ATTRIB)
                res = skt->attr_res;
        else
                res = skt->common_res;

        map->static_start = res->start + map->card_start;
        return 0;
}

static struct pccard_operations bcm63xx_pcmcia_operations = {
        .init                   = bcm63xx_pcmcia_sock_init,
        .suspend                = bcm63xx_pcmcia_suspend,
        .get_status             = bcm63xx_pcmcia_get_status,
        .set_socket             = bcm63xx_pcmcia_set_socket,
        .set_io_map             = bcm63xx_pcmcia_set_io_map,
        .set_mem_map            = bcm63xx_pcmcia_set_mem_map,
};

/*
 * register pcmcia socket to core
 */
static int bcm63xx_drv_pcmcia_probe(struct platform_device *pdev)
{
        struct bcm63xx_pcmcia_socket *skt;
        struct pcmcia_socket *sock;
        struct resource *res, *irq_res;
        unsigned int regmem_size = 0, iomem_size = 0;
        u32 val;
        int ret;

        skt = kzalloc(sizeof(*skt), GFP_KERNEL);
        if (!skt)
                return -ENOMEM;
        spin_lock_init(&skt->lock);
        sock = &skt->socket;
        sock->driver_data = skt;

        /* make sure we have all resources we need */
        skt->common_res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
        skt->attr_res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
        irq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
        skt->pd = pdev->dev.platform_data;
        if (!skt->common_res || !skt->attr_res || !irq_res || !skt->pd) {
                ret = -EINVAL;
                goto err;
        }

        /* remap pcmcia registers */
        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        regmem_size = resource_size(res);
        if (!request_mem_region(res->start, regmem_size, "bcm63xx_pcmcia")) {
                ret = -EINVAL;
                goto err;
        }
        skt->reg_res = res;

        skt->base = ioremap(res->start, regmem_size);
        if (!skt->base) {
                ret = -ENOMEM;
                goto err;
        }

        /* remap io registers */
        res = platform_get_resource(pdev, IORESOURCE_MEM, 3);
        iomem_size = resource_size(res);
        skt->io_base = ioremap(res->start, iomem_size);
        if (!skt->io_base) {
                ret = -ENOMEM;
                goto err;
        }

        /* resources are static */
        sock->resource_ops = &pccard_static_ops;
        sock->ops = &bcm63xx_pcmcia_operations;
        sock->owner = THIS_MODULE;
        sock->dev.parent = &pdev->dev;
        sock->features = SS_CAP_STATIC_MAP | SS_CAP_PCCARD;
        sock->io_offset = (unsigned long)skt->io_base;
        sock->pci_irq = irq_res->start;

#ifdef CONFIG_CARDBUS
        sock->cb_dev = bcm63xx_cb_dev;
        if (bcm63xx_cb_dev)
                sock->features |= SS_CAP_CARDBUS;
#endif

        /* assume common & attribute memory have the same size */
        sock->map_size = resource_size(skt->common_res);

        /* initialize polling timer */
        timer_setup(&skt->timer, bcm63xx_pcmcia_poll, 0);

        /* initialize  pcmcia  control register,  drive  VS[12] to  0,
         * leave CB IDSEL to the old  value since it is set by the PCI
         * layer */
        val = pcmcia_readl(skt, PCMCIA_C1_REG);
        val &= PCMCIA_C1_CBIDSEL_MASK;
        val |= PCMCIA_C1_EN_PCMCIA_GPIO_MASK;
        pcmcia_writel(skt, val, PCMCIA_C1_REG);

        /*
         * Hardware has only one set of timings registers, not one for
         * each memory access type, so we configure them for the
         * slowest one: attribute memory.
         */
        val = PCMCIA_C2_DATA16_MASK;
        val |= 10 << PCMCIA_C2_RWCOUNT_SHIFT;
        val |= 6 << PCMCIA_C2_INACTIVE_SHIFT;
        val |= 3 << PCMCIA_C2_SETUP_SHIFT;
        val |= 3 << PCMCIA_C2_HOLD_SHIFT;
        pcmcia_writel(skt, val, PCMCIA_C2_REG);

        ret = pcmcia_register_socket(sock);
        if (ret)
                goto err;

        /* start polling socket */
        mod_timer(&skt->timer,
                  jiffies + msecs_to_jiffies(BCM63XX_PCMCIA_POLL_RATE));

        platform_set_drvdata(pdev, skt);
        return 0;

err:
        if (skt->io_base)
                iounmap(skt->io_base);
        if (skt->base)
                iounmap(skt->base);
        if (skt->reg_res)
                release_mem_region(skt->reg_res->start, regmem_size);
        kfree(skt);
        return ret;
}

static int bcm63xx_drv_pcmcia_remove(struct platform_device *pdev)
{
        struct bcm63xx_pcmcia_socket *skt;
        struct resource *res;

        skt = platform_get_drvdata(pdev);
        del_timer_sync(&skt->timer);
        iounmap(skt->base);
        iounmap(skt->io_base);
        res = skt->reg_res;
        release_mem_region(res->start, resource_size(res));
        kfree(skt);
        return 0;
}

struct platform_driver bcm63xx_pcmcia_driver = {
        .probe  = bcm63xx_drv_pcmcia_probe,
        .remove = bcm63xx_drv_pcmcia_remove,
        .driver = {
                .name   = "bcm63xx_pcmcia",
                .owner  = THIS_MODULE,
        },
};

#ifdef CONFIG_CARDBUS
static int bcm63xx_cb_probe(struct pci_dev *dev,
                                      const struct pci_device_id *id)
{
        /* keep pci device */
        bcm63xx_cb_dev = dev;
        return platform_driver_register(&bcm63xx_pcmcia_driver);
}

static void bcm63xx_cb_exit(struct pci_dev *dev)
{
        platform_driver_unregister(&bcm63xx_pcmcia_driver);
        bcm63xx_cb_dev = NULL;
}

static const struct pci_device_id bcm63xx_cb_table[] = {
        {
                .vendor         = PCI_VENDOR_ID_BROADCOM,
                .device         = BCM6348_CPU_ID,
                .subvendor      = PCI_VENDOR_ID_BROADCOM,
                .subdevice      = PCI_ANY_ID,
                .class          = PCI_CLASS_BRIDGE_CARDBUS << 8,
                .class_mask     = ~0,
        },

        {
                .vendor         = PCI_VENDOR_ID_BROADCOM,
                .device         = BCM6358_CPU_ID,
                .subvendor      = PCI_VENDOR_ID_BROADCOM,
                .subdevice      = PCI_ANY_ID,
                .class          = PCI_CLASS_BRIDGE_CARDBUS << 8,
                .class_mask     = ~0,
        },

        { },
};

MODULE_DEVICE_TABLE(pci, bcm63xx_cb_table);

static struct pci_driver bcm63xx_cardbus_driver = {
        .name           = "bcm63xx_cardbus",
        .id_table       = bcm63xx_cb_table,
        .probe          = bcm63xx_cb_probe,
        .remove         = bcm63xx_cb_exit,
};
#endif

/*
 * if cardbus support is enabled, register our platform device after
 * our fake cardbus bridge has been registered
 */
static int __init bcm63xx_pcmcia_init(void)
{
#ifdef CONFIG_CARDBUS
        return pci_register_driver(&bcm63xx_cardbus_driver);
#else
        return platform_driver_register(&bcm63xx_pcmcia_driver);
#endif
}

static void __exit bcm63xx_pcmcia_exit(void)
{
#ifdef CONFIG_CARDBUS
        return pci_unregister_driver(&bcm63xx_cardbus_driver);
#else
        platform_driver_unregister(&bcm63xx_pcmcia_driver);
#endif
}

module_init(bcm63xx_pcmcia_init);
module_exit(bcm63xx_pcmcia_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Maxime Bizon <mbizon@freebox.fr>");
MODULE_DESCRIPTION("Linux PCMCIA Card Services: bcm63xx Socket Controller");