/*
 *  linux/drivers/mmc/core/mmc_ops.h
 *
 *  Copyright 2006-2007 Pierre Ossman
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or (at
 * your option) any later version.
 */

#include <linux/slab.h>
#include <linux/types.h>
#include <linux/scatterlist.h>

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

#include "core.h"
#include "mmc_ops.h"

static int _mmc_select_card(struct mmc_host *host, struct mmc_card *card)
{
        int err;
        struct mmc_command cmd = {0};

        BUG_ON(!host);

        cmd.opcode = MMC_SELECT_CARD;

        if (card) {
                cmd.arg = card->rca << 16;
                cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
        } else {
                cmd.arg = 0;
                cmd.flags = MMC_RSP_NONE | MMC_CMD_AC;
        }

        err = mmc_wait_for_cmd(host, &cmd, MMC_CMD_RETRIES);
        if (err)
                return err;

        return 0;
}

int mmc_select_card(struct mmc_card *card)
{
        BUG_ON(!card);

        return _mmc_select_card(card->host, card);
}

int mmc_deselect_cards(struct mmc_host *host)
{
        return _mmc_select_card(host, NULL);
}

int mmc_card_sleepawake(struct mmc_host *host, int sleep)
{
        struct mmc_command cmd = {0};
        struct mmc_card *card = host->card;
        int err;

        if (sleep)
                mmc_deselect_cards(host);

        cmd.opcode = MMC_SLEEP_AWAKE;
        cmd.arg = card->rca << 16;
        if (sleep)
                cmd.arg |= 1 << 15;

        cmd.flags = MMC_RSP_R1B | MMC_CMD_AC;
        err = mmc_wait_for_cmd(host, &cmd, 0);
        if (err)
                return err;

        /*
         * If the host does not wait while the card signals busy, then we will
         * will have to wait the sleep/awake timeout.  Note, we cannot use the
         * SEND_STATUS command to poll the status because that command (and most
         * others) is invalid while the card sleeps.
         */
        if (!(host->caps & MMC_CAP_WAIT_WHILE_BUSY))
                mmc_delay(DIV_ROUND_UP(card->ext_csd.sa_timeout, 10000));

        if (!sleep)
                err = mmc_select_card(card);

        return err;
}

int mmc_go_idle(struct mmc_host *host)
{
        int err;
        struct mmc_command cmd = {0};

        /*
         * Non-SPI hosts need to prevent chipselect going active during
         * GO_IDLE; that would put chips into SPI mode.  Remind them of
         * that in case of hardware that won't pull up DAT3/nCS otherwise.
         *
         * SPI hosts ignore ios.chip_select; it's managed according to
         * rules that must accommodate non-MMC slaves which this layer
         * won't even know about.
         */
        if (!mmc_host_is_spi(host)) {
                mmc_set_chip_select(host, MMC_CS_HIGH);
                mmc_delay(1);
        }

        cmd.opcode = MMC_GO_IDLE_STATE;
        cmd.arg = 0;
        cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_NONE | MMC_CMD_BC;

        err = mmc_wait_for_cmd(host, &cmd, 0);

        mmc_delay(1);

        if (!mmc_host_is_spi(host)) {
                mmc_set_chip_select(host, MMC_CS_DONTCARE);
                mmc_delay(1);
        }

        host->use_spi_crc = 0;

        return err;
}

int mmc_send_op_cond(struct mmc_host *host, u32 ocr, u32 *rocr)
{
        struct mmc_command cmd = {0};
        int i, err = 0;

        BUG_ON(!host);

        cmd.opcode = MMC_SEND_OP_COND;
        cmd.arg = mmc_host_is_spi(host) ? 0 : ocr;
        cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R3 | MMC_CMD_BCR;

        for (i = 100; i; i--) {
                err = mmc_wait_for_cmd(host, &cmd, 0);
                if (err)
                        break;

                /* if we're just probing, do a single pass */
                if (ocr == 0)
                        break;

                /* otherwise wait until reset completes */
                if (mmc_host_is_spi(host)) {
                        if (!(cmd.resp[0] & R1_SPI_IDLE))
                                break;
                } else {
                        if (cmd.resp[0] & MMC_CARD_BUSY)
                                break;
                }

                err = -ETIMEDOUT;

                mmc_delay(10);
        }

        if (rocr && !mmc_host_is_spi(host))
                *rocr = cmd.resp[0];

        return err;
}

int mmc_all_send_cid(struct mmc_host *host, u32 *cid)
{
        int err;
        struct mmc_command cmd = {0};

        BUG_ON(!host);
        BUG_ON(!cid);

        cmd.opcode = MMC_ALL_SEND_CID;
        cmd.arg = 0;
        cmd.flags = MMC_RSP_R2 | MMC_CMD_BCR;

        err = mmc_wait_for_cmd(host, &cmd, MMC_CMD_RETRIES);
        if (err)
                return err;

        memcpy(cid, cmd.resp, sizeof(u32) * 4);

        return 0;
}

int mmc_set_relative_addr(struct mmc_card *card)
{
        int err;
        struct mmc_command cmd = {0};

        BUG_ON(!card);
        BUG_ON(!card->host);

        cmd.opcode = MMC_SET_RELATIVE_ADDR;
        cmd.arg = card->rca << 16;
        cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;

        err = mmc_wait_for_cmd(card->host, &cmd, MMC_CMD_RETRIES);
        if (err)
                return err;

        return 0;
}

static int
mmc_send_cxd_native(struct mmc_host *host, u32 arg, u32 *cxd, int opcode)
{
        int err;
        struct mmc_command cmd = {0};

        BUG_ON(!host);
        BUG_ON(!cxd);

        cmd.opcode = opcode;
        cmd.arg = arg;
        cmd.flags = MMC_RSP_R2 | MMC_CMD_AC;

        err = mmc_wait_for_cmd(host, &cmd, MMC_CMD_RETRIES);
        if (err)
                return err;

        memcpy(cxd, cmd.resp, sizeof(u32) * 4);

        return 0;
}

static int
mmc_send_cxd_data(struct mmc_card *card, struct mmc_host *host,
                u32 opcode, void *buf, unsigned len)
{
        struct mmc_request mrq = {0};
        struct mmc_command cmd = {0};
        struct mmc_data data = {0};
        struct scatterlist sg;
        void *data_buf;

        /* dma onto stack is unsafe/nonportable, but callers to this
         * routine normally provide temporary on-stack buffers ...
         */
        data_buf = kmalloc(len, GFP_KERNEL);
        if (data_buf == NULL)
                return -ENOMEM;

        mrq.cmd = &cmd;
        mrq.data = &data;

        cmd.opcode = opcode;
        cmd.arg = 0;

        /* NOTE HACK:  the MMC_RSP_SPI_R1 is always correct here, but we
         * rely on callers to never use this with "native" calls for reading
         * CSD or CID.  Native versions of those commands use the R2 type,
         * not R1 plus a data block.
         */
        cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_ADTC;

        data.blksz = len;
        data.blocks = 1;
        data.flags = MMC_DATA_READ;
        data.sg = &sg;
        data.sg_len = 1;

        sg_init_one(&sg, data_buf, len);

        if (opcode == MMC_SEND_CSD || opcode == MMC_SEND_CID) {
                /*
                 * The spec states that CSR and CID accesses have a timeout
                 * of 64 clock cycles.
                 */
                data.timeout_ns = 0;
                data.timeout_clks = 64;
        } else
                mmc_set_data_timeout(&data, card);

        mmc_wait_for_req(host, &mrq);

        memcpy(buf, data_buf, len);
        kfree(data_buf);

        if (cmd.error)
                return cmd.error;
        if (data.error)
                return data.error;

        return 0;
}

int mmc_send_csd(struct mmc_card *card, u32 *csd)
{
        int ret, i;

        if (!mmc_host_is_spi(card->host))
                return mmc_send_cxd_native(card->host, card->rca << 16,
                                csd, MMC_SEND_CSD);

        ret = mmc_send_cxd_data(card, card->host, MMC_SEND_CSD, csd, 16);
        if (ret)
                return ret;

        for (i = 0;i < 4;i++)
                csd[i] = be32_to_cpu(csd[i]);

        return 0;
}

int mmc_send_cid(struct mmc_host *host, u32 *cid)
{
        int ret, i;

        if (!mmc_host_is_spi(host)) {
                if (!host->card)
                        return -EINVAL;
                return mmc_send_cxd_native(host, host->card->rca << 16,
                                cid, MMC_SEND_CID);
        }

        ret = mmc_send_cxd_data(NULL, host, MMC_SEND_CID, cid, 16);
        if (ret)
                return ret;

        for (i = 0;i < 4;i++)
                cid[i] = be32_to_cpu(cid[i]);

        return 0;
}

int mmc_send_ext_csd(struct mmc_card *card, u8 *ext_csd)
{
        return mmc_send_cxd_data(card, card->host, MMC_SEND_EXT_CSD,
                        ext_csd, 512);
}

int mmc_spi_read_ocr(struct mmc_host *host, int highcap, u32 *ocrp)
{
        struct mmc_command cmd = {0};
        int err;

        cmd.opcode = MMC_SPI_READ_OCR;
        cmd.arg = highcap ? (1 << 30) : 0;
        cmd.flags = MMC_RSP_SPI_R3;

        err = mmc_wait_for_cmd(host, &cmd, 0);

        *ocrp = cmd.resp[1];
        return err;
}

int mmc_spi_set_crc(struct mmc_host *host, int use_crc)
{
        struct mmc_command cmd = {0};
        int err;

        cmd.opcode = MMC_SPI_CRC_ON_OFF;
        cmd.flags = MMC_RSP_SPI_R1;
        cmd.arg = use_crc;

        err = mmc_wait_for_cmd(host, &cmd, 0);
        if (!err)
                host->use_spi_crc = use_crc;
        return err;
}

/**
 *      mmc_switch - modify EXT_CSD register
 *      @card: the MMC card associated with the data transfer
 *      @set: cmd set values
 *      @index: EXT_CSD register index
 *      @value: value to program into EXT_CSD register
 *      @timeout_ms: timeout (ms) for operation performed by register write,
 *                   timeout of zero implies maximum possible timeout
 *
 *      Modifies the EXT_CSD register for selected card.
 */
int mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value,
               unsigned int timeout_ms)
{
        int err;
        struct mmc_command cmd = {0};
        u32 status;

        BUG_ON(!card);
        BUG_ON(!card->host);

        cmd.opcode = MMC_SWITCH;
        cmd.arg = (MMC_SWITCH_MODE_WRITE_BYTE << 24) |
                  (index << 16) |
                  (value << 8) |
                  set;
        cmd.flags = MMC_RSP_SPI_R1B | MMC_RSP_R1B | MMC_CMD_AC;
        cmd.cmd_timeout_ms = timeout_ms;

        err = mmc_wait_for_cmd(card->host, &cmd, MMC_CMD_RETRIES);
        if (err)
                return err;

        /* Must check status to be sure of no errors */
        do {
                err = mmc_send_status(card, &status);
                if (err)
                        return err;
                if (card->host->caps & MMC_CAP_WAIT_WHILE_BUSY)
                        break;
                if (mmc_host_is_spi(card->host))
                        break;
        } while (R1_CURRENT_STATE(status) == R1_STATE_PRG);

        if (mmc_host_is_spi(card->host)) {
                if (status & R1_SPI_ILLEGAL_COMMAND)
                        return -EBADMSG;
        } else {
                if (status & 0xFDFFA000)
                        printk(KERN_WARNING "%s: unexpected status %#x after "
                               "switch", mmc_hostname(card->host), status);
                if (status & R1_SWITCH_ERROR)
                        return -EBADMSG;
        }

        return 0;
}
EXPORT_SYMBOL_GPL(mmc_switch);

int mmc_send_status(struct mmc_card *card, u32 *status)
{
        int err;
        struct mmc_command cmd = {0};

        BUG_ON(!card);
        BUG_ON(!card->host);

        cmd.opcode = MMC_SEND_STATUS;
        if (!mmc_host_is_spi(card->host))
                cmd.arg = card->rca << 16;
        cmd.flags = MMC_RSP_SPI_R2 | MMC_RSP_R1 | MMC_CMD_AC;

        err = mmc_wait_for_cmd(card->host, &cmd, MMC_CMD_RETRIES);
        if (err)
                return err;

        /* NOTE: callers are required to understand the difference
         * between "native" and SPI format status words!
         */
        if (status)
                *status = cmd.resp[0];

        return 0;
}

static int
mmc_send_bus_test(struct mmc_card *card, struct mmc_host *host, u8 opcode,
                  u8 len)
{
        struct mmc_request mrq = {0};
        struct mmc_command cmd = {0};
        struct mmc_data data = {0};
        struct scatterlist sg;
        u8 *data_buf;
        u8 *test_buf;
        int i, err;
        static u8 testdata_8bit[8] = { 0x55, 0xaa, 0, 0, 0, 0, 0, 0 };
        static u8 testdata_4bit[4] = { 0x5a, 0, 0, 0 };

        /* dma onto stack is unsafe/nonportable, but callers to this
         * routine normally provide temporary on-stack buffers ...
         */
        data_buf = kmalloc(len, GFP_KERNEL);
        if (!data_buf)
                return -ENOMEM;

        if (len == 8)
                test_buf = testdata_8bit;
        else if (len == 4)
                test_buf = testdata_4bit;
        else {
                printk(KERN_ERR "%s: Invalid bus_width %d\n",
                       mmc_hostname(host), len);
                kfree(data_buf);
                return -EINVAL;
        }

        if (opcode == MMC_BUS_TEST_W)
                memcpy(data_buf, test_buf, len);

        mrq.cmd = &cmd;
        mrq.data = &data;
        cmd.opcode = opcode;
        cmd.arg = 0;

        /* NOTE HACK:  the MMC_RSP_SPI_R1 is always correct here, but we
         * rely on callers to never use this with "native" calls for reading
         * CSD or CID.  Native versions of those commands use the R2 type,
         * not R1 plus a data block.
         */
        cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_ADTC;

        data.blksz = len;
        data.blocks = 1;
        if (opcode == MMC_BUS_TEST_R)
                data.flags = MMC_DATA_READ;
        else
                data.flags = MMC_DATA_WRITE;

        data.sg = &sg;
        data.sg_len = 1;
        sg_init_one(&sg, data_buf, len);
        mmc_wait_for_req(host, &mrq);
        err = 0;
        if (opcode == MMC_BUS_TEST_R) {
                for (i = 0; i < len / 4; i++)
                        if ((test_buf[i] ^ data_buf[i]) != 0xff) {
                                err = -EIO;
                                break;
                        }
        }
        kfree(data_buf);

        if (cmd.error)
                return cmd.error;
        if (data.error)
                return data.error;

        return err;
}

int mmc_bus_test(struct mmc_card *card, u8 bus_width)
{
        int err, width;

        if (bus_width == MMC_BUS_WIDTH_8)
                width = 8;
        else if (bus_width == MMC_BUS_WIDTH_4)
                width = 4;
        else if (bus_width == MMC_BUS_WIDTH_1)
                return 0; /* no need for test */
        else
                return -EINVAL;

        /*
         * Ignore errors from BUS_TEST_W.  BUS_TEST_R will fail if there
         * is a problem.  This improves chances that the test will work.
         */
        mmc_send_bus_test(card, card->host, MMC_BUS_TEST_W, width);
        err = mmc_send_bus_test(card, card->host, MMC_BUS_TEST_R, width);
        return err;
}