// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * at91_cf.c -- AT91 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/interrupt.h>
#include <linux/slab.h>
#include <linux/gpio.h>
#include <linux/io.h>
#include <linux/sizes.h>
#include <linux/mfd/syscon.h>
#include <linux/mfd/syscon/atmel-mc.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_gpio.h>
#include <linux/pci.h>
#include <linux/regmap.h>

#include <pcmcia/ss.h>

/*
 * A0..A10 work in each range; A23 indicates I/O space;  A25 is CFRNW;
 * some other bit in {A24,A22..A11} is nREG to flag memory access
 * (vs attributes).  So more than 2KB/region would just be waste.
 * Note: These are offsets from the physical base address.
 */
#define CF_ATTR_PHYS    (0)
#define CF_IO_PHYS      (1 << 23)
#define CF_MEM_PHYS     (0x017ff800)

struct at91_cf_data {
        int     irq_pin;                /* I/O IRQ */
        int     det_pin;                /* Card detect */
        int     vcc_pin;                /* power switching */
        int     rst_pin;                /* card reset */
        u8      chipselect;             /* EBI Chip Select number */
        u8      flags;
#define AT91_CF_TRUE_IDE        0x01
#define AT91_IDE_SWAP_A0_A2     0x02
};

struct regmap *mc;

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

struct at91_cf_socket {
        struct pcmcia_socket    socket;

        unsigned                present:1;

        struct platform_device  *pdev;
        struct at91_cf_data     *board;

        unsigned long           phys_baseaddr;
};

static inline int at91_cf_present(struct at91_cf_socket *cf)
{
        return !gpio_get_value(cf->board->det_pin);
}

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

static int at91_cf_ss_init(struct pcmcia_socket *s)
{
        return 0;
}

static irqreturn_t at91_cf_irq(int irq, void *_cf)
{
        struct at91_cf_socket *cf = _cf;

        if (irq == gpio_to_irq(cf->board->det_pin)) {
                unsigned present = at91_cf_present(cf);

                /* kick pccard as needed */
                if (present != cf->present) {
                        cf->present = present;
                        dev_dbg(&cf->pdev->dev, "card %s\n",
                                        present ? "present" : "gone");
                        pcmcia_parse_events(&cf->socket, SS_DETECT);
                }
        }

        return IRQ_HANDLED;
}

static int at91_cf_get_status(struct pcmcia_socket *s, u_int *sp)
{
        struct at91_cf_socket   *cf;

        if (!sp)
                return -EINVAL;

        cf = container_of(s, struct at91_cf_socket, socket);

        /* NOTE: CF is always 3VCARD */
        if (at91_cf_present(cf)) {
                int rdy = gpio_is_valid(cf->board->irq_pin);    /* RDY/nIRQ */
                int vcc = gpio_is_valid(cf->board->vcc_pin);

                *sp = SS_DETECT | SS_3VCARD;
                if (!rdy || gpio_get_value(cf->board->irq_pin))
                        *sp |= SS_READY;
                if (!vcc || gpio_get_value(cf->board->vcc_pin))
                        *sp |= SS_POWERON;
        } else
                *sp = 0;

        return 0;
}

static int
at91_cf_set_socket(struct pcmcia_socket *sock, struct socket_state_t *s)
{
        struct at91_cf_socket   *cf;

        cf = container_of(sock, struct at91_cf_socket, socket);

        /* switch Vcc if needed and possible */
        if (gpio_is_valid(cf->board->vcc_pin)) {
                switch (s->Vcc) {
                case 0:
                        gpio_set_value(cf->board->vcc_pin, 0);
                        break;
                case 33:
                        gpio_set_value(cf->board->vcc_pin, 1);
                        break;
                default:
                        return -EINVAL;
                }
        }

        /* toggle reset if needed */
        gpio_set_value(cf->board->rst_pin, s->flags & SS_RESET);

        dev_dbg(&cf->pdev->dev, "Vcc %d, io_irq %d, flags %04x csc %04x\n",
                                s->Vcc, s->io_irq, s->flags, s->csc_mask);

        return 0;
}

static int at91_cf_ss_suspend(struct pcmcia_socket *s)
{
        return at91_cf_set_socket(s, &dead_socket);
}

/* we already mapped the I/O region */
static int at91_cf_set_io_map(struct pcmcia_socket *s, struct pccard_io_map *io)
{
        struct at91_cf_socket   *cf;
        u32                     csr;

        cf = container_of(s, struct at91_cf_socket, socket);
        io->flags &= (MAP_ACTIVE | MAP_16BIT | MAP_AUTOSZ);

        /*
         * Use 16 bit accesses unless/until we need 8-bit i/o space.
         *
         * NOTE: this CF controller ignores IOIS16, so we can't really do
         * MAP_AUTOSZ.  The 16bit mode allows single byte access on either
         * D0-D7 (even addr) or D8-D15 (odd), so it's close enough for many
         * purposes (and handles ide-cs).
         *
         * The 8bit mode is needed for odd byte access on D0-D7.  It seems
         * some cards only like that way to get at the odd byte, despite
         * CF 3.0 spec table 35 also giving the D8-D15 option.
         */
        if (!(io->flags & (MAP_16BIT | MAP_AUTOSZ))) {
                csr = AT91_MC_SMC_DBW_8;
                dev_dbg(&cf->pdev->dev, "8bit i/o bus\n");
        } else {
                csr = AT91_MC_SMC_DBW_16;
                dev_dbg(&cf->pdev->dev, "16bit i/o bus\n");
        }
        regmap_update_bits(mc, AT91_MC_SMC_CSR(cf->board->chipselect),
                           AT91_MC_SMC_DBW, csr);

        io->start = cf->socket.io_offset;
        io->stop = io->start + SZ_2K - 1;

        return 0;
}

/* pcmcia layer maps/unmaps mem regions */
static int
at91_cf_set_mem_map(struct pcmcia_socket *s, struct pccard_mem_map *map)
{
        struct at91_cf_socket   *cf;

        if (map->card_start)
                return -EINVAL;

        cf = container_of(s, struct at91_cf_socket, socket);

        map->flags &= (MAP_ACTIVE | MAP_ATTRIB | MAP_16BIT);
        if (map->flags & MAP_ATTRIB)
                map->static_start = cf->phys_baseaddr + CF_ATTR_PHYS;
        else
                map->static_start = cf->phys_baseaddr + CF_MEM_PHYS;

        return 0;
}

static struct pccard_operations at91_cf_ops = {
        .init                   = at91_cf_ss_init,
        .suspend                = at91_cf_ss_suspend,
        .get_status             = at91_cf_get_status,
        .set_socket             = at91_cf_set_socket,
        .set_io_map             = at91_cf_set_io_map,
        .set_mem_map            = at91_cf_set_mem_map,
};

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

static const struct of_device_id at91_cf_dt_ids[] = {
        { .compatible = "atmel,at91rm9200-cf" },
        { /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, at91_cf_dt_ids);

static int at91_cf_probe(struct platform_device *pdev)
{
        struct at91_cf_socket   *cf;
        struct at91_cf_data     *board;
        struct resource         *io;
        struct resource         realio;
        int                     status;

        board = devm_kzalloc(&pdev->dev, sizeof(*board), GFP_KERNEL);
        if (!board)
                return -ENOMEM;

        board->irq_pin = of_get_gpio(pdev->dev.of_node, 0);
        board->det_pin = of_get_gpio(pdev->dev.of_node, 1);
        board->vcc_pin = of_get_gpio(pdev->dev.of_node, 2);
        board->rst_pin = of_get_gpio(pdev->dev.of_node, 3);

        mc = syscon_regmap_lookup_by_compatible("atmel,at91rm9200-sdramc");
        if (IS_ERR(mc))
                return PTR_ERR(mc);

        if (!gpio_is_valid(board->det_pin) || !gpio_is_valid(board->rst_pin))
                return -ENODEV;

        io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        if (!io)
                return -ENODEV;

        cf = devm_kzalloc(&pdev->dev, sizeof(*cf), GFP_KERNEL);
        if (!cf)
                return -ENOMEM;

        cf->board = board;
        cf->pdev = pdev;
        cf->phys_baseaddr = io->start;
        platform_set_drvdata(pdev, cf);

        /* must be a GPIO; ergo must trigger on both edges */
        status = devm_gpio_request(&pdev->dev, board->det_pin, "cf_det");
        if (status < 0)
                return status;

        status = devm_request_irq(&pdev->dev, gpio_to_irq(board->det_pin),
                                        at91_cf_irq, 0, "at91_cf detect", cf);
        if (status < 0)
                return status;

        device_init_wakeup(&pdev->dev, 1);

        status = devm_gpio_request(&pdev->dev, board->rst_pin, "cf_rst");
        if (status < 0)
                goto fail0a;

        if (gpio_is_valid(board->vcc_pin)) {
                status = devm_gpio_request(&pdev->dev, board->vcc_pin, "cf_vcc");
                if (status < 0)
                        goto fail0a;
        }

        /*
         * The card driver will request this irq later as needed.
         * but it causes lots of "irqNN: nobody cared" messages
         * unless we report that we handle everything (sigh).
         * (Note:  DK board doesn't wire the IRQ pin...)
         */
        if (gpio_is_valid(board->irq_pin)) {
                status = devm_gpio_request(&pdev->dev, board->irq_pin, "cf_irq");
                if (status < 0)
                        goto fail0a;

                status = devm_request_irq(&pdev->dev, gpio_to_irq(board->irq_pin),
                                        at91_cf_irq, IRQF_SHARED, "at91_cf", cf);
                if (status < 0)
                        goto fail0a;
                cf->socket.pci_irq = gpio_to_irq(board->irq_pin);
        } else
                cf->socket.pci_irq = nr_irqs + 1;

        /*
         * pcmcia layer only remaps "real" memory not iospace
         * io_offset is set to 0x10000 to avoid the check in static_find_io().
         * */
        cf->socket.io_offset = 0x10000;
        realio.start = cf->socket.io_offset;
        realio.end = realio.start + SZ_64K - 1;
        status = pci_remap_iospace(&realio, cf->phys_baseaddr + CF_IO_PHYS);
        if (status)
                goto fail0a;

        /* reserve chip-select regions */
        if (!devm_request_mem_region(&pdev->dev, io->start, resource_size(io), "at91_cf")) {
                status = -ENXIO;
                goto fail0a;
        }

        dev_info(&pdev->dev, "irqs det #%d, io #%d\n",
                gpio_to_irq(board->det_pin), gpio_to_irq(board->irq_pin));

        cf->socket.owner = THIS_MODULE;
        cf->socket.dev.parent = &pdev->dev;
        cf->socket.ops = &at91_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 = io;

        status = pcmcia_register_socket(&cf->socket);
        if (status < 0)
                goto fail0a;

        return 0;

fail0a:
        device_init_wakeup(&pdev->dev, 0);
        return status;
}

static int at91_cf_remove(struct platform_device *pdev)
{
        struct at91_cf_socket   *cf = platform_get_drvdata(pdev);

        pcmcia_unregister_socket(&cf->socket);
        device_init_wakeup(&pdev->dev, 0);

        return 0;
}

#ifdef  CONFIG_PM

static int at91_cf_suspend(struct platform_device *pdev, pm_message_t mesg)
{
        struct at91_cf_socket   *cf = platform_get_drvdata(pdev);
        struct at91_cf_data     *board = cf->board;

        if (device_may_wakeup(&pdev->dev)) {
                enable_irq_wake(gpio_to_irq(board->det_pin));
                if (gpio_is_valid(board->irq_pin))
                        enable_irq_wake(gpio_to_irq(board->irq_pin));
        }
        return 0;
}

static int at91_cf_resume(struct platform_device *pdev)
{
        struct at91_cf_socket   *cf = platform_get_drvdata(pdev);
        struct at91_cf_data     *board = cf->board;

        if (device_may_wakeup(&pdev->dev)) {
                disable_irq_wake(gpio_to_irq(board->det_pin));
                if (gpio_is_valid(board->irq_pin))
                        disable_irq_wake(gpio_to_irq(board->irq_pin));
        }

        return 0;
}

#else
#define at91_cf_suspend         NULL
#define at91_cf_resume          NULL
#endif

static struct platform_driver at91_cf_driver = {
        .driver = {
                .name           = "at91_cf",
                .of_match_table = at91_cf_dt_ids,
        },
        .probe          = at91_cf_probe,
        .remove         = at91_cf_remove,
        .suspend        = at91_cf_suspend,
        .resume         = at91_cf_resume,
};

module_platform_driver(at91_cf_driver);

MODULE_DESCRIPTION("AT91 Compact Flash Driver");
MODULE_AUTHOR("David Brownell");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:at91_cf");