// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * omap_cf.c -- OMAP 16xx CompactFlash controller driver
 *
 * Copyright (c) 2005 David Brownell
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/slab.h>

#include <pcmcia/ss.h>

#include <asm/io.h>
#include <linux/sizes.h>

#include <linux/soc/ti/omap1-io.h>
#include <linux/soc/ti/omap1-soc.h>
#include <linux/soc/ti/omap1-mux.h>

/* NOTE:  don't expect this to support many I/O cards.  The 16xx chips have
 * hard-wired timings to support Compact Flash memory cards; they won't work
 * with various other devices (like WLAN adapters) without some external
 * logic to help out.
 *
 * NOTE:  CF controller docs disagree with address space docs as to where
 * CF_BASE really lives; this is a doc erratum.
 */
#define CF_BASE 0xfffe2800

/* status; read after IRQ */
#define CF_STATUS                       (CF_BASE + 0x00)
#       define  CF_STATUS_BAD_READ      (1 << 2)
#       define  CF_STATUS_BAD_WRITE     (1 << 1)
#       define  CF_STATUS_CARD_DETECT   (1 << 0)

/* which chipselect (CS0..CS3) is used for CF (active low) */
#define CF_CFG                          (CF_BASE + 0x02)

/* card reset */
#define CF_CONTROL                      (CF_BASE + 0x04)
#       define  CF_CONTROL_RESET        (1 << 0)

#define omap_cf_present() (!(omap_readw(CF_STATUS) & CF_STATUS_CARD_DETECT))

/*--------------------------------------------------------------------------*/

static const char driver_name[] = "omap_cf";

struct omap_cf_socket {
        struct pcmcia_socket    socket;

        struct timer_list       timer;
        unsigned                present:1;
        unsigned                active:1;

        struct platform_device  *pdev;
        unsigned long           phys_cf;
        u_int                   irq;
        struct resource         iomem;
};

#define POLL_INTERVAL           (2 * HZ)

/*--------------------------------------------------------------------------*/

static int omap_cf_ss_init(struct pcmcia_socket *s)
{
        return 0;
}

/* the timer is primarily to kick this socket's pccardd */
static void omap_cf_timer(struct timer_list *t)
{
        struct omap_cf_socket   *cf = timer_container_of(cf, t, timer);
        unsigned                present = omap_cf_present();

        if (present != cf->present) {
                cf->present = present;
                pr_debug("%s: card %s\n", driver_name,
                        present ? "present" : "gone");
                pcmcia_parse_events(&cf->socket, SS_DETECT);
        }

        if (cf->active)
                mod_timer(&cf->timer, jiffies + POLL_INTERVAL);
}

/* This irq handler prevents "irqNNN: nobody cared" messages as drivers
 * claim the card's IRQ.  It may also detect some card insertions, but
 * not removals; it can't always eliminate timer irqs.
 */
static irqreturn_t omap_cf_irq(int irq, void *_cf)
{
        struct omap_cf_socket *cf = (struct omap_cf_socket *)_cf;

        omap_cf_timer(&cf->timer);
        return IRQ_HANDLED;
}

static int omap_cf_get_status(struct pcmcia_socket *s, u_int *sp)
{
        if (!sp)
                return -EINVAL;

        /* NOTE CF is always 3VCARD */
        if (omap_cf_present()) {
                struct omap_cf_socket   *cf;

                *sp = SS_READY | SS_DETECT | SS_POWERON | SS_3VCARD;
                cf = container_of(s, struct omap_cf_socket, socket);
                s->pcmcia_irq = 0;
                s->pci_irq = cf->irq;
        } else
                *sp = 0;
        return 0;
}

static int
omap_cf_set_socket(struct pcmcia_socket *sock, struct socket_state_t *s)
{
        /* REVISIT some non-OSK boards may support power switching */
        switch (s->Vcc) {
        case 0:
        case 33:
                break;
        default:
                return -EINVAL;
        }

        omap_readw(CF_CONTROL);
        if (s->flags & SS_RESET)
                omap_writew(CF_CONTROL_RESET, CF_CONTROL);
        else
                omap_writew(0, CF_CONTROL);

        pr_debug("%s: Vcc %d, io_irq %d, flags %04x csc %04x\n",
                driver_name, s->Vcc, s->io_irq, s->flags, s->csc_mask);

        return 0;
}

static int omap_cf_ss_suspend(struct pcmcia_socket *s)
{
        pr_debug("%s: %s\n", driver_name, __func__);
        return omap_cf_set_socket(s, &dead_socket);
}

/* regions are 2K each:  mem, attrib, io (and reserved-for-ide) */

static int
omap_cf_set_io_map(struct pcmcia_socket *s, struct pccard_io_map *io)
{
        struct omap_cf_socket   *cf;

        cf = container_of(s, struct omap_cf_socket, socket);
        io->flags &= MAP_ACTIVE|MAP_ATTRIB|MAP_16BIT;
        io->start = cf->phys_cf + SZ_4K;
        io->stop = io->start + SZ_2K - 1;
        return 0;
}

static int
omap_cf_set_mem_map(struct pcmcia_socket *s, struct pccard_mem_map *map)
{
        struct omap_cf_socket   *cf;

        if (map->card_start)
                return -EINVAL;
        cf = container_of(s, struct omap_cf_socket, socket);
        map->static_start = cf->phys_cf;
        map->flags &= MAP_ACTIVE|MAP_ATTRIB|MAP_16BIT;
        if (map->flags & MAP_ATTRIB)
                map->static_start += SZ_2K;
        return 0;
}

static struct pccard_operations omap_cf_ops = {
        .init                   = omap_cf_ss_init,
        .suspend                = omap_cf_ss_suspend,
        .get_status             = omap_cf_get_status,
        .set_socket             = omap_cf_set_socket,
        .set_io_map             = omap_cf_set_io_map,
        .set_mem_map            = omap_cf_set_mem_map,
};

/*--------------------------------------------------------------------------*/

/*
 * NOTE:  right now the only board-specific platform_data is
 * "what chipselect is used".  Boards could want more.
 */

static int __init omap_cf_probe(struct platform_device *pdev)
{
        unsigned                seg;
        struct omap_cf_socket   *cf;
        int                     irq;
        int                     status;
        struct resource         *res;
        struct resource         iospace = DEFINE_RES_IO(SZ_64, SZ_4K);

        seg = (int) pdev->dev.platform_data;
        if (seg == 0 || seg > 3)
                return -ENODEV;

        /* either CFLASH.IREQ (INT_1610_CF) or some GPIO */
        irq = platform_get_irq(pdev, 0);
        if (irq < 0)
                return -EINVAL;

        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        if (!res)
                return -EINVAL;

        cf = kzalloc_obj(*cf);
        if (!cf)
                return -ENOMEM;
        timer_setup(&cf->timer, omap_cf_timer, 0);

        cf->pdev = pdev;
        platform_set_drvdata(pdev, cf);

        /* this primarily just shuts up irq handling noise */
        status = request_irq(irq, omap_cf_irq, IRQF_SHARED,
                        driver_name, cf);
        if (status < 0)
                goto fail0;
        cf->irq = irq;
        cf->socket.pci_irq = irq;
        cf->phys_cf = res->start;

        /* pcmcia layer only remaps "real" memory */
        cf->socket.io_offset = iospace.start;
        status = pci_remap_iospace(&iospace, cf->phys_cf + SZ_4K);
        if (status) {
                status = -ENOMEM;
                goto fail1;
        }

        if (!request_mem_region(cf->phys_cf, SZ_8K, driver_name)) {
                status = -ENXIO;
                goto fail1;
        }

        /* NOTE:  CF conflicts with MMC1 */
        omap_cfg_reg(W11_1610_CF_CD1);
        omap_cfg_reg(P11_1610_CF_CD2);
        omap_cfg_reg(R11_1610_CF_IOIS16);
        omap_cfg_reg(V10_1610_CF_IREQ);
        omap_cfg_reg(W10_1610_CF_RESET);

        omap_writew(~(1 << seg), CF_CFG);

        pr_info("%s: cs%d on irq %d\n", driver_name, seg, irq);

        /* CF uses armxor_ck, which is "always" available */

        pr_debug("%s: sts %04x cfg %04x control %04x %s\n", driver_name,
                omap_readw(CF_STATUS), omap_readw(CF_CFG),
                omap_readw(CF_CONTROL),
                omap_cf_present() ? "present" : "(not present)");

        cf->socket.owner = THIS_MODULE;
        cf->socket.dev.parent = &pdev->dev;
        cf->socket.ops = &omap_cf_ops;
        cf->socket.resource_ops = &pccard_static_ops;
        cf->socket.features = SS_CAP_PCCARD | SS_CAP_STATIC_MAP
                                | SS_CAP_MEM_ALIGN;
        cf->socket.map_size = SZ_2K;
        cf->socket.io[0].res = &cf->iomem;

        status = pcmcia_register_socket(&cf->socket);
        if (status < 0)
                goto fail2;

        cf->active = 1;
        mod_timer(&cf->timer, jiffies + POLL_INTERVAL);
        return 0;

fail2:
        release_mem_region(cf->phys_cf, SZ_8K);
fail1:
        free_irq(irq, cf);
fail0:
        kfree(cf);
        return status;
}

static void __exit omap_cf_remove(struct platform_device *pdev)
{
        struct omap_cf_socket *cf = platform_get_drvdata(pdev);

        cf->active = 0;
        pcmcia_unregister_socket(&cf->socket);
        timer_shutdown_sync(&cf->timer);
        release_mem_region(cf->phys_cf, SZ_8K);
        free_irq(cf->irq, cf);
        kfree(cf);
}

/*
 * omap_cf_remove() lives in .exit.text. For drivers registered via
 * platform_driver_probe() this is ok because they cannot get unbound at
 * runtime. So mark the driver struct with __refdata to prevent modpost
 * triggering a section mismatch warning.
 */
static struct platform_driver omap_cf_driver __refdata = {
        .driver = {
                .name   = driver_name,
        },
        .remove         = __exit_p(omap_cf_remove),
};

static int __init omap_cf_init(void)
{
        if (cpu_is_omap16xx())
                return platform_driver_probe(&omap_cf_driver, omap_cf_probe);
        return -ENODEV;
}

static void __exit omap_cf_exit(void)
{
        if (cpu_is_omap16xx())
                platform_driver_unregister(&omap_cf_driver);
}

module_init(omap_cf_init);
module_exit(omap_cf_exit);

MODULE_DESCRIPTION("OMAP CF Driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:omap_cf");