// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  sdricoh_cs.c - driver for Ricoh Secure Digital Card Readers that can be
 *     found on some Ricoh RL5c476 II cardbus bridge
 *
 *  Copyright (C) 2006 - 2008 Sascha Sommer <saschasommer@freenet.de>
 */

/*
#define DEBUG
#define VERBOSE_DEBUG
*/
#include <linux/delay.h>
#include <linux/highmem.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/ioport.h>
#include <linux/iopoll.h>
#include <linux/scatterlist.h>

#include <pcmcia/cistpl.h>
#include <pcmcia/ds.h>
#include <linux/io.h>

#include <linux/mmc/host.h>
#include <linux/mmc/mmc.h>

#define DRIVER_NAME "sdricoh_cs"

static unsigned int switchlocked;

/* i/o region */
#define SDRICOH_PCI_REGION 0
#define SDRICOH_PCI_REGION_SIZE 0x1000

/* registers */
#define R104_VERSION     0x104
#define R200_CMD         0x200
#define R204_CMD_ARG     0x204
#define R208_DATAIO      0x208
#define R20C_RESP        0x20c
#define R21C_STATUS      0x21c
#define R2E0_INIT        0x2e0
#define R2E4_STATUS_RESP 0x2e4
#define R2F0_RESET       0x2f0
#define R224_MODE        0x224
#define R226_BLOCKSIZE   0x226
#define R228_POWER       0x228
#define R230_DATA        0x230

/* flags for the R21C_STATUS register */
#define STATUS_CMD_FINISHED      0x00000001
#define STATUS_TRANSFER_FINISHED 0x00000004
#define STATUS_CARD_INSERTED     0x00000020
#define STATUS_CARD_LOCKED       0x00000080
#define STATUS_CMD_TIMEOUT       0x00400000
#define STATUS_READY_TO_READ     0x01000000
#define STATUS_READY_TO_WRITE    0x02000000
#define STATUS_BUSY              0x40000000

/* timeouts */
#define SDRICOH_CMD_TIMEOUT_US  1000000
#define SDRICOH_DATA_TIMEOUT_US 1000000

/* list of supported pcmcia devices */
static const struct pcmcia_device_id pcmcia_ids[] = {
        /* vendor and device strings followed by their crc32 hashes */
        PCMCIA_DEVICE_PROD_ID12("RICOH", "Bay1Controller", 0xd9f522ed,
                                0xc3901202),
        PCMCIA_DEVICE_PROD_ID12("RICOH", "Bay Controller", 0xd9f522ed,
                                0xace80909),
        PCMCIA_DEVICE_NULL,
};

MODULE_DEVICE_TABLE(pcmcia, pcmcia_ids);

/* mmc privdata */
struct sdricoh_host {
        struct device *dev;
        struct mmc_host *mmc;   /* MMC structure */
        unsigned char __iomem *iobase;
        struct pci_dev *pci_dev;
        int app_cmd;
};

/***************** register i/o helper functions *****************************/

static inline unsigned int sdricoh_readl(struct sdricoh_host *host,
                                         unsigned int reg)
{
        unsigned int value = readl(host->iobase + reg);
        dev_vdbg(host->dev, "rl %x 0x%x\n", reg, value);
        return value;
}

static inline void sdricoh_writel(struct sdricoh_host *host, unsigned int reg,
                                  unsigned int value)
{
        writel(value, host->iobase + reg);
        dev_vdbg(host->dev, "wl %x 0x%x\n", reg, value);

}

static inline void sdricoh_writew(struct sdricoh_host *host, unsigned int reg,
                                         unsigned short value)
{
        writew(value, host->iobase + reg);
        dev_vdbg(host->dev, "ww %x 0x%x\n", reg, value);
}

static inline unsigned int sdricoh_readb(struct sdricoh_host *host,
                                         unsigned int reg)
{
        unsigned int value = readb(host->iobase + reg);
        dev_vdbg(host->dev, "rb %x 0x%x\n", reg, value);
        return value;
}

static bool sdricoh_status_ok(struct sdricoh_host *host, unsigned int status,
                              unsigned int wanted)
{
        sdricoh_writel(host, R2E4_STATUS_RESP, status);
        return status & wanted;
}

static int sdricoh_query_status(struct sdricoh_host *host, unsigned int wanted)
{
        int ret;
        unsigned int status = 0;
        struct device *dev = host->dev;

        ret = read_poll_timeout(sdricoh_readl, status,
                                sdricoh_status_ok(host, status, wanted),
                                32, SDRICOH_DATA_TIMEOUT_US, false,
                                host, R21C_STATUS);
        if (ret) {
                dev_err(dev, "query_status: timeout waiting for %x\n", wanted);
                return -ETIMEDOUT;
        }

        /* do not do this check in the loop as some commands fail otherwise */
        if (status & 0x7F0000) {
                dev_err(dev, "waiting for status bit %x failed\n", wanted);
                return -EINVAL;
        }
        return 0;

}

static int sdricoh_mmc_cmd(struct sdricoh_host *host, struct mmc_command *cmd)
{
        unsigned int status, timeout_us;
        int ret;
        unsigned char opcode = cmd->opcode;

        /* reset status reg? */
        sdricoh_writel(host, R21C_STATUS, 0x18);

        /* MMC_APP_CMDs need some special handling */
        if (host->app_cmd) {
                opcode |= 64;
                host->app_cmd = 0;
        } else if (opcode == MMC_APP_CMD)
                host->app_cmd = 1;

        /* fill parameters */
        sdricoh_writel(host, R204_CMD_ARG, cmd->arg);
        sdricoh_writel(host, R200_CMD, (0x10000 << 8) | opcode);

        /* wait for command completion */
        if (!opcode)
                return 0;

        timeout_us = cmd->busy_timeout ? cmd->busy_timeout * 1000 :
                SDRICOH_CMD_TIMEOUT_US;

        ret = read_poll_timeout(sdricoh_readl, status,
                        sdricoh_status_ok(host, status, STATUS_CMD_FINISHED),
                        32, timeout_us, false,
                        host, R21C_STATUS);

        /*
         * Don't check for timeout status in the loop, as it's not always reset
         * correctly.
         */
        if (ret || status & STATUS_CMD_TIMEOUT)
                return -ETIMEDOUT;

        return 0;
}

static int sdricoh_reset(struct sdricoh_host *host)
{
        dev_dbg(host->dev, "reset\n");
        sdricoh_writel(host, R2F0_RESET, 0x10001);
        sdricoh_writel(host, R2E0_INIT, 0x10000);
        if (sdricoh_readl(host, R2E0_INIT) != 0x10000)
                return -EIO;
        sdricoh_writel(host, R2E0_INIT, 0x10007);

        sdricoh_writel(host, R224_MODE, 0x2000000);
        sdricoh_writel(host, R228_POWER, 0xe0);


        /* status register ? */
        sdricoh_writel(host, R21C_STATUS, 0x18);

        return 0;
}

static int sdricoh_blockio(struct sdricoh_host *host, int read,
                                u8 *buf, int len)
{
        int size;
        u32 data = 0;
        /* wait until the data is available */
        if (read) {
                if (sdricoh_query_status(host, STATUS_READY_TO_READ))
                        return -ETIMEDOUT;
                sdricoh_writel(host, R21C_STATUS, 0x18);
                /* read data */
                while (len) {
                        data = sdricoh_readl(host, R230_DATA);
                        size = min(len, 4);
                        len -= size;
                        while (size) {
                                *buf = data & 0xFF;
                                buf++;
                                data >>= 8;
                                size--;
                        }
                }
        } else {
                if (sdricoh_query_status(host, STATUS_READY_TO_WRITE))
                        return -ETIMEDOUT;
                sdricoh_writel(host, R21C_STATUS, 0x18);
                /* write data */
                while (len) {
                        size = min(len, 4);
                        len -= size;
                        while (size) {
                                data >>= 8;
                                data |= (u32)*buf << 24;
                                buf++;
                                size--;
                        }
                        sdricoh_writel(host, R230_DATA, data);
                }
        }

        return 0;
}

static void sdricoh_request(struct mmc_host *mmc, struct mmc_request *mrq)
{
        struct sdricoh_host *host = mmc_priv(mmc);
        struct mmc_command *cmd = mrq->cmd;
        struct mmc_data *data = cmd->data;
        struct device *dev = host->dev;
        int i;

        dev_dbg(dev, "=============================\n");
        dev_dbg(dev, "sdricoh_request opcode=%i\n", cmd->opcode);

        sdricoh_writel(host, R21C_STATUS, 0x18);

        /* read/write commands seem to require this */
        if (data) {
                sdricoh_writew(host, R226_BLOCKSIZE, data->blksz);
                sdricoh_writel(host, R208_DATAIO, 0);
        }

        cmd->error = sdricoh_mmc_cmd(host, cmd);

        /* read response buffer */
        if (cmd->flags & MMC_RSP_PRESENT) {
                if (cmd->flags & MMC_RSP_136) {
                        /* CRC is stripped so we need to do some shifting. */
                        for (i = 0; i < 4; i++) {
                                cmd->resp[i] =
                                    sdricoh_readl(host,
                                                  R20C_RESP + (3 - i) * 4) << 8;
                                if (i != 3)
                                        cmd->resp[i] |=
                                            sdricoh_readb(host, R20C_RESP +
                                                          (3 - i) * 4 - 1);
                        }
                } else
                        cmd->resp[0] = sdricoh_readl(host, R20C_RESP);
        }

        /* transfer data */
        if (data && cmd->error == 0) {
                dev_dbg(dev, "transfer: blksz %i blocks %i sg_len %i "
                        "sg length %i\n", data->blksz, data->blocks,
                        data->sg_len, data->sg->length);

                /* enter data reading mode */
                sdricoh_writel(host, R21C_STATUS, 0x837f031e);
                for (i = 0; i < data->blocks; i++) {
                        size_t len = data->blksz;
                        u8 *buf;
                        struct page *page;
                        int result;
                        page = sg_page(data->sg);

                        buf = kmap(page) + data->sg->offset + (len * i);
                        result =
                                sdricoh_blockio(host,
                                        data->flags & MMC_DATA_READ, buf, len);
                        kunmap(page);
                        flush_dcache_page(page);
                        if (result) {
                                dev_err(dev, "sdricoh_request: cmd %i "
                                        "block transfer failed\n", cmd->opcode);
                                cmd->error = result;
                                break;
                        } else
                                data->bytes_xfered += len;
                }

                sdricoh_writel(host, R208_DATAIO, 1);

                if (sdricoh_query_status(host, STATUS_TRANSFER_FINISHED)) {
                        dev_err(dev, "sdricoh_request: transfer end error\n");
                        cmd->error = -EINVAL;
                }
        }
        /* FIXME check busy flag */

        mmc_request_done(mmc, mrq);
        dev_dbg(dev, "=============================\n");
}

static void sdricoh_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
{
        struct sdricoh_host *host = mmc_priv(mmc);
        dev_dbg(host->dev, "set_ios\n");

        if (ios->power_mode == MMC_POWER_ON) {
                sdricoh_writel(host, R228_POWER, 0xc0e0);

                if (ios->bus_width == MMC_BUS_WIDTH_4) {
                        sdricoh_writel(host, R224_MODE, 0x2000300);
                        sdricoh_writel(host, R228_POWER, 0x40e0);
                } else {
                        sdricoh_writel(host, R224_MODE, 0x2000340);
                }

        } else if (ios->power_mode == MMC_POWER_UP) {
                sdricoh_writel(host, R224_MODE, 0x2000320);
                sdricoh_writel(host, R228_POWER, 0xe0);
        }
}

static int sdricoh_get_ro(struct mmc_host *mmc)
{
        struct sdricoh_host *host = mmc_priv(mmc);
        unsigned int status;

        status = sdricoh_readl(host, R21C_STATUS);
        sdricoh_writel(host, R2E4_STATUS_RESP, status);

        /* some notebooks seem to have the locked flag switched */
        if (switchlocked)
                return !(status & STATUS_CARD_LOCKED);

        return (status & STATUS_CARD_LOCKED);
}

static const struct mmc_host_ops sdricoh_ops = {
        .request = sdricoh_request,
        .set_ios = sdricoh_set_ios,
        .get_ro = sdricoh_get_ro,
};

/* initialize the control and register it to the mmc framework */
static int sdricoh_init_mmc(struct pci_dev *pci_dev,
                            struct pcmcia_device *pcmcia_dev)
{
        int result;
        void __iomem *iobase;
        struct mmc_host *mmc;
        struct sdricoh_host *host;
        struct device *dev = &pcmcia_dev->dev;
        /* map iomem */
        if (pci_resource_len(pci_dev, SDRICOH_PCI_REGION) !=
            SDRICOH_PCI_REGION_SIZE) {
                dev_dbg(dev, "unexpected pci resource len\n");
                return -ENODEV;
        }
        iobase =
            pci_iomap(pci_dev, SDRICOH_PCI_REGION, SDRICOH_PCI_REGION_SIZE);
        if (!iobase) {
                dev_err(dev, "unable to map iobase\n");
                return -ENODEV;
        }
        /* check version? */
        if (readl(iobase + R104_VERSION) != 0x4000) {
                dev_dbg(dev, "no supported mmc controller found\n");
                result = -ENODEV;
                goto unmap_io;
        }
        /* allocate privdata */
        mmc = pcmcia_dev->priv =
            devm_mmc_alloc_host(&pcmcia_dev->dev, sizeof(*host));
        if (!mmc) {
                dev_err(dev, "devm_mmc_alloc_host failed\n");
                result = -ENOMEM;
                goto unmap_io;
        }
        host = mmc_priv(mmc);

        host->iobase = iobase;
        host->dev = dev;
        host->pci_dev = pci_dev;

        mmc->ops = &sdricoh_ops;

        /* FIXME: frequency and voltage handling is done by the controller
         */
        mmc->f_min = 450000;
        mmc->f_max = 24000000;
        mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34;
        mmc->caps |= MMC_CAP_4_BIT_DATA;

        mmc->max_seg_size = 1024 * 512;
        mmc->max_blk_size = 512;

        /* reset the controller */
        if (sdricoh_reset(host)) {
                dev_dbg(dev, "could not reset\n");
                result = -EIO;
                goto unmap_io;
        }

        result = mmc_add_host(mmc);

        if (!result) {
                dev_dbg(dev, "mmc host registered\n");
                return 0;
        }
unmap_io:
        pci_iounmap(pci_dev, iobase);
        return result;
}

/* search for supported mmc controllers */
static int sdricoh_pcmcia_probe(struct pcmcia_device *pcmcia_dev)
{
        struct pci_dev *pci_dev = NULL;

        dev_info(&pcmcia_dev->dev, "Searching MMC controller for pcmcia device"
                " %s %s ...\n", pcmcia_dev->prod_id[0], pcmcia_dev->prod_id[1]);

        /* search pci cardbus bridge that contains the mmc controller */
        /* the io region is already claimed by yenta_socket... */
        while ((pci_dev =
                pci_get_device(PCI_VENDOR_ID_RICOH, PCI_DEVICE_ID_RICOH_RL5C476,
                               pci_dev))) {
                /* try to init the device */
                if (!sdricoh_init_mmc(pci_dev, pcmcia_dev)) {
                        dev_info(&pcmcia_dev->dev, "MMC controller found\n");
                        return 0;
                }

        }
        dev_err(&pcmcia_dev->dev, "No MMC controller was found.\n");
        return -ENODEV;
}

static void sdricoh_pcmcia_detach(struct pcmcia_device *link)
{
        struct mmc_host *mmc = link->priv;

        dev_dbg(&link->dev, "detach\n");

        /* remove mmc host */
        if (mmc) {
                struct sdricoh_host *host = mmc_priv(mmc);
                mmc_remove_host(mmc);
                pci_iounmap(host->pci_dev, host->iobase);
                pci_dev_put(host->pci_dev);
        }
        pcmcia_disable_device(link);
}

#ifdef CONFIG_PM
static int sdricoh_pcmcia_suspend(struct pcmcia_device *link)
{
        dev_dbg(&link->dev, "suspend\n");
        return 0;
}

static int sdricoh_pcmcia_resume(struct pcmcia_device *link)
{
        struct mmc_host *mmc = link->priv;
        dev_dbg(&link->dev, "resume\n");
        sdricoh_reset(mmc_priv(mmc));
        return 0;
}
#else
#define sdricoh_pcmcia_suspend NULL
#define sdricoh_pcmcia_resume NULL
#endif

static struct pcmcia_driver sdricoh_driver = {
        .name = DRIVER_NAME,
        .probe = sdricoh_pcmcia_probe,
        .remove = sdricoh_pcmcia_detach,
        .id_table = pcmcia_ids,
        .suspend = sdricoh_pcmcia_suspend,
        .resume = sdricoh_pcmcia_resume,
};
module_pcmcia_driver(sdricoh_driver);

module_param(switchlocked, uint, 0444);

MODULE_AUTHOR("Sascha Sommer <saschasommer@freenet.de>");
MODULE_DESCRIPTION("Ricoh PCMCIA Secure Digital Interface driver");
MODULE_LICENSE("GPL");

MODULE_PARM_DESC(switchlocked, "Switch the cards locked status."
                "Use this when unlocked cards are shown readonly (default 0)");