/*
 * (C) Copyright 2007-2011
 * Allwinner Technology Co., Ltd. <www.allwinnertech.com>
 * Aaron <leafy.myeh@allwinnertech.com>
 *
 * MMC driver for allwinner sunxi platform.
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

#include <common.h>
#include <malloc.h>
#include <mmc.h>
#include <asm/io.h>
#include <asm/arch/clock.h>
#include <asm/arch/cpu.h>
#include <asm/arch/gpio.h>
#include <asm/arch/mmc.h>
#include <asm-generic/gpio.h>

struct sunxi_mmc_host {
	unsigned mmc_no;
	uint32_t *mclkreg;
	unsigned fatal_err;
	unsigned mod_clk;
	struct sunxi_mmc *reg;
	struct mmc_config cfg;
};

/* support 4 mmc hosts */
struct sunxi_mmc_host mmc_host[4];

static int sunxi_mmc_getcd_gpio(int sdc_no)
{
	switch (sdc_no) {
	case 0: return sunxi_name_to_gpio(CONFIG_MMC0_CD_PIN);
	case 1: return sunxi_name_to_gpio(CONFIG_MMC1_CD_PIN);
	case 2: return sunxi_name_to_gpio(CONFIG_MMC2_CD_PIN);
	case 3: return sunxi_name_to_gpio(CONFIG_MMC3_CD_PIN);
	}
	return -1;
}

static int mmc_resource_init(int sdc_no)
{
	struct sunxi_mmc_host *mmchost = &mmc_host[sdc_no];
	struct sunxi_ccm_reg *ccm = (struct sunxi_ccm_reg *)SUNXI_CCM_BASE;
	int cd_pin, ret = 0;

	debug("init mmc %d resource\n", sdc_no);

	switch (sdc_no) {
	case 0:
		mmchost->reg = (struct sunxi_mmc *)SUNXI_MMC0_BASE;
		mmchost->mclkreg = &ccm->sd0_clk_cfg;
		break;
	case 1:
		mmchost->reg = (struct sunxi_mmc *)SUNXI_MMC1_BASE;
		mmchost->mclkreg = &ccm->sd1_clk_cfg;
		break;
	case 2:
		mmchost->reg = (struct sunxi_mmc *)SUNXI_MMC2_BASE;
		mmchost->mclkreg = &ccm->sd2_clk_cfg;
		break;
	case 3:
		mmchost->reg = (struct sunxi_mmc *)SUNXI_MMC3_BASE;
		mmchost->mclkreg = &ccm->sd3_clk_cfg;
		break;
	default:
		printf("Wrong mmc number %d\n", sdc_no);
		return -1;
	}
	mmchost->mmc_no = sdc_no;

	cd_pin = sunxi_mmc_getcd_gpio(sdc_no);
	if (cd_pin != -1)
		ret = gpio_request(cd_pin, "mmc_cd");

	return ret;
}

static int mmc_clk_io_on(int sdc_no)
{
	unsigned int pll_clk;
	unsigned int divider;
	struct sunxi_mmc_host *mmchost = &mmc_host[sdc_no];
	struct sunxi_ccm_reg *ccm = (struct sunxi_ccm_reg *)SUNXI_CCM_BASE;

	debug("init mmc %d clock and io\n", sdc_no);

	/* config ahb clock */
	setbits_le32(&ccm->ahb_gate0, 1 << AHB_GATE_OFFSET_MMC(sdc_no));

#if defined(CONFIG_MACH_SUN6I) || defined(CONFIG_MACH_SUN8I)
	/* unassert reset */
	setbits_le32(&ccm->ahb_reset0_cfg, 1 << AHB_RESET_OFFSET_MMC(sdc_no));
#endif

	/* config mod clock */
	pll_clk = clock_get_pll6();
	/* should be close to 100 MHz but no more, so round up */
	divider = ((pll_clk + 99999999) / 100000000) - 1;
	writel(CCM_MMC_CTRL_ENABLE | CCM_MMC_CTRL_PLL6 | divider,
	       mmchost->mclkreg);
	mmchost->mod_clk = pll_clk / (divider + 1);

	return 0;
}

static int mmc_update_clk(struct mmc *mmc)
{
	struct sunxi_mmc_host *mmchost = mmc->priv;
	unsigned int cmd;
	unsigned timeout_msecs = 2000;

	cmd = SUNXI_MMC_CMD_START |
	      SUNXI_MMC_CMD_UPCLK_ONLY |
	      SUNXI_MMC_CMD_WAIT_PRE_OVER;
	writel(cmd, &mmchost->reg->cmd);
	while (readl(&mmchost->reg->cmd) & SUNXI_MMC_CMD_START) {
		if (!timeout_msecs--)
			return -1;
		udelay(1000);
	}

	/* clock update sets various irq status bits, clear these */
	writel(readl(&mmchost->reg->rint), &mmchost->reg->rint);

	return 0;
}

static int mmc_config_clock(struct mmc *mmc, unsigned div)
{
	struct sunxi_mmc_host *mmchost = mmc->priv;
	unsigned rval = readl(&mmchost->reg->clkcr);

	/* Disable Clock */
	rval &= ~SUNXI_MMC_CLK_ENABLE;
	writel(rval, &mmchost->reg->clkcr);
	if (mmc_update_clk(mmc))
		return -1;

	/* Change Divider Factor */
	rval &= ~SUNXI_MMC_CLK_DIVIDER_MASK;
	rval |= div;
	writel(rval, &mmchost->reg->clkcr);
	if (mmc_update_clk(mmc))
		return -1;
	/* Re-enable Clock */
	rval |= SUNXI_MMC_CLK_ENABLE;
	writel(rval, &mmchost->reg->clkcr);

	if (mmc_update_clk(mmc))
		return -1;

	return 0;
}

static void mmc_set_ios(struct mmc *mmc)
{
	struct sunxi_mmc_host *mmchost = mmc->priv;
	unsigned int clkdiv = 0;

	debug("set ios: bus_width: %x, clock: %d, mod_clk: %d\n",
	      mmc->bus_width, mmc->clock, mmchost->mod_clk);

	/* Change clock first */
	clkdiv = (mmchost->mod_clk + (mmc->clock >> 1)) / mmc->clock / 2;
	if (mmc->clock) {
		if (mmc_config_clock(mmc, clkdiv)) {
			mmchost->fatal_err = 1;
			return;
		}
	}

	/* Change bus width */
	if (mmc->bus_width == 8)
		writel(0x2, &mmchost->reg->width);
	else if (mmc->bus_width == 4)
		writel(0x1, &mmchost->reg->width);
	else
		writel(0x0, &mmchost->reg->width);
}

static int mmc_core_init(struct mmc *mmc)
{
	struct sunxi_mmc_host *mmchost = mmc->priv;

	/* Reset controller */
	writel(SUNXI_MMC_GCTRL_RESET, &mmchost->reg->gctrl);
	udelay(1000);

	return 0;
}

static int mmc_trans_data_by_cpu(struct mmc *mmc, struct mmc_data *data)
{
	struct sunxi_mmc_host *mmchost = mmc->priv;
	const int reading = !!(data->flags & MMC_DATA_READ);
	const uint32_t status_bit = reading ? SUNXI_MMC_STATUS_FIFO_EMPTY :
					      SUNXI_MMC_STATUS_FIFO_FULL;
	unsigned i;
	unsigned byte_cnt = data->blocksize * data->blocks;
	unsigned timeout_msecs = 2000;
	unsigned *buff = (unsigned int *)(reading ? data->dest : data->src);

	/* Always read / write data through the CPU */
	setbits_le32(&mmchost->reg->gctrl, SUNXI_MMC_GCTRL_ACCESS_BY_AHB);

	for (i = 0; i < (byte_cnt >> 2); i++) {
		while (readl(&mmchost->reg->status) & status_bit) {
			if (!timeout_msecs--)
				return -1;
			udelay(1000);
		}

		if (reading)
			buff[i] = readl(&mmchost->reg->fifo);
		else
			writel(buff[i], &mmchost->reg->fifo);
	}

	return 0;
}

static int mmc_rint_wait(struct mmc *mmc, unsigned int timeout_msecs,
			 unsigned int done_bit, const char *what)
{
	struct sunxi_mmc_host *mmchost = mmc->priv;
	unsigned int status;

	do {
		status = readl(&mmchost->reg->rint);
		if (!timeout_msecs-- ||
		    (status & SUNXI_MMC_RINT_INTERRUPT_ERROR_BIT)) {
			debug("%s timeout %x\n", what,
			      status & SUNXI_MMC_RINT_INTERRUPT_ERROR_BIT);
			return TIMEOUT;
		}
		udelay(1000);
	} while (!(status & done_bit));

	return 0;
}

static int mmc_send_cmd(struct mmc *mmc, struct mmc_cmd *cmd,
			struct mmc_data *data)
{
	struct sunxi_mmc_host *mmchost = mmc->priv;
	unsigned int cmdval = SUNXI_MMC_CMD_START;
	unsigned int timeout_msecs;
	int error = 0;
	unsigned int status = 0;
	unsigned int bytecnt = 0;

	if (mmchost->fatal_err)
		return -1;
	if (cmd->resp_type & MMC_RSP_BUSY)
		debug("mmc cmd %d check rsp busy\n", cmd->cmdidx);
	if (cmd->cmdidx == 12)
		return 0;

	if (!cmd->cmdidx)
		cmdval |= SUNXI_MMC_CMD_SEND_INIT_SEQ;
	if (cmd->resp_type & MMC_RSP_PRESENT)
		cmdval |= SUNXI_MMC_CMD_RESP_EXPIRE;
	if (cmd->resp_type & MMC_RSP_136)
		cmdval |= SUNXI_MMC_CMD_LONG_RESPONSE;
	if (cmd->resp_type & MMC_RSP_CRC)
		cmdval |= SUNXI_MMC_CMD_CHK_RESPONSE_CRC;

	if (data) {
		if ((u32) data->dest & 0x3) {
			error = -1;
			goto out;
		}

		cmdval |= SUNXI_MMC_CMD_DATA_EXPIRE|SUNXI_MMC_CMD_WAIT_PRE_OVER;
		if (data->flags & MMC_DATA_WRITE)
			cmdval |= SUNXI_MMC_CMD_WRITE;
		if (data->blocks > 1)
			cmdval |= SUNXI_MMC_CMD_AUTO_STOP;
		writel(data->blocksize, &mmchost->reg->blksz);
		writel(data->blocks * data->blocksize, &mmchost->reg->bytecnt);
	}

	debug("mmc %d, cmd %d(0x%08x), arg 0x%08x\n", mmchost->mmc_no,
	      cmd->cmdidx, cmdval | cmd->cmdidx, cmd->cmdarg);
	writel(cmd->cmdarg, &mmchost->reg->arg);

	if (!data)
		writel(cmdval | cmd->cmdidx, &mmchost->reg->cmd);

	/*
	 * transfer data and check status
	 * STATREG[2] : FIFO empty
	 * STATREG[3] : FIFO full
	 */
	if (data) {
		int ret = 0;

		bytecnt = data->blocksize * data->blocks;
		debug("trans data %d bytes\n", bytecnt);
		writel(cmdval | cmd->cmdidx, &mmchost->reg->cmd);
		ret = mmc_trans_data_by_cpu(mmc, data);
		if (ret) {
			error = readl(&mmchost->reg->rint) & \
				SUNXI_MMC_RINT_INTERRUPT_ERROR_BIT;
			error = TIMEOUT;
			goto out;
		}
	}

	error = mmc_rint_wait(mmc, 0xfffff, SUNXI_MMC_RINT_COMMAND_DONE, "cmd");
	if (error)
		goto out;

	if (data) {
		timeout_msecs = 120;
		debug("cacl timeout %x msec\n", timeout_msecs);
		error = mmc_rint_wait(mmc, timeout_msecs,
				      data->blocks > 1 ?
				      SUNXI_MMC_RINT_AUTO_COMMAND_DONE :
				      SUNXI_MMC_RINT_DATA_OVER,
				      "data");
		if (error)
			goto out;
	}

	if (cmd->resp_type & MMC_RSP_BUSY) {
		timeout_msecs = 2000;
		do {
			status = readl(&mmchost->reg->status);
			if (!timeout_msecs--) {
				debug("busy timeout\n");
				error = TIMEOUT;
				goto out;
			}
			udelay(1000);
		} while (status & SUNXI_MMC_STATUS_CARD_DATA_BUSY);
	}

	if (cmd->resp_type & MMC_RSP_136) {
		cmd->response[0] = readl(&mmchost->reg->resp3);
		cmd->response[1] = readl(&mmchost->reg->resp2);
		cmd->response[2] = readl(&mmchost->reg->resp1);
		cmd->response[3] = readl(&mmchost->reg->resp0);
		debug("mmc resp 0x%08x 0x%08x 0x%08x 0x%08x\n",
		      cmd->response[3], cmd->response[2],
		      cmd->response[1], cmd->response[0]);
	} else {
		cmd->response[0] = readl(&mmchost->reg->resp0);
		debug("mmc resp 0x%08x\n", cmd->response[0]);
	}
out:
	if (error < 0) {
		writel(SUNXI_MMC_GCTRL_RESET, &mmchost->reg->gctrl);
		mmc_update_clk(mmc);
	}
	writel(0xffffffff, &mmchost->reg->rint);
	writel(readl(&mmchost->reg->gctrl) | SUNXI_MMC_GCTRL_FIFO_RESET,
	       &mmchost->reg->gctrl);

	return error;
}

static int sunxi_mmc_getcd(struct mmc *mmc)
{
	struct sunxi_mmc_host *mmchost = mmc->priv;
	int cd_pin;

	cd_pin = sunxi_mmc_getcd_gpio(mmchost->mmc_no);
	if (cd_pin == -1)
		return 1;

	return !gpio_direction_input(cd_pin);
}

static const struct mmc_ops sunxi_mmc_ops = {
	.send_cmd	= mmc_send_cmd,
	.set_ios	= mmc_set_ios,
	.init		= mmc_core_init,
	.getcd		= sunxi_mmc_getcd,
};

struct mmc *sunxi_mmc_init(int sdc_no)
{
	struct mmc_config *cfg = &mmc_host[sdc_no].cfg;

	memset(&mmc_host[sdc_no], 0, sizeof(struct sunxi_mmc_host));

	cfg->name = "SUNXI SD/MMC";
	cfg->ops  = &sunxi_mmc_ops;

	cfg->voltages = MMC_VDD_32_33 | MMC_VDD_33_34;
	cfg->host_caps = MMC_MODE_4BIT;
	cfg->host_caps |= MMC_MODE_HS_52MHz | MMC_MODE_HS;
#if defined(CONFIG_MACH_SUN6I) || defined(CONFIG_MACH_SUN7I) || defined(CONFIG_MACH_SUN8I)
	cfg->host_caps |= MMC_MODE_HC;
#endif
	cfg->b_max = CONFIG_SYS_MMC_MAX_BLK_COUNT;

	cfg->f_min = 400000;
	cfg->f_max = 52000000;

	if (mmc_resource_init(sdc_no) != 0)
		return NULL;

	mmc_clk_io_on(sdc_no);

	return mmc_create(cfg, &mmc_host[sdc_no]);
}