/*
 * Copyright (C) 2013 Lucas Stach <l.stach@pengutronix.de>
 *
 * Partly based on code (C) Copyright 2010-2013
 * NVIDIA Corporation <www.nvidia.com>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <common.h>
#include <clock.h>
#include <driver.h>
#include <dma.h>
#include <gpio.h>
#include <init.h>
#include <io.h>
#include <malloc.h>
#include <mci.h>
#include <of_gpio.h>
#include <linux/clk.h>
#include <linux/reset.h>
#include <linux/err.h>

#include "sdhci.h"

#define TEGRA_SDMMC_PRESENT_STATE			0x024
#define  TEGRA_SDMMC_PRESENT_STATE_CMD_INHIBIT_CMD	(1 << 0)
#define  TEGRA_SDMMC_PRESENT_STATE_CMD_INHIBIT_DAT	(1 << 1)

#define TEGRA_SDMMC_PWR_CNTL				0x028
#define  TEGRA_SDMMC_PWR_CNTL_SD_BUS			(1 << 8)
#define  TEGRA_SDMMC_PWR_CNTL_33_V			(7 << 9)

#define TEGRA_SDMMC_CLK_CNTL				0x02c
#define  TEGRA_SDMMC_CLK_CNTL_SW_RESET_FOR_ALL		(1 << 24)
#define  TEGRA_SDMMC_CLK_CNTL_SD_CLOCK_EN		(1 << 2)
#define  TEGRA_SDMMC_CLK_INTERNAL_CLOCK_STABLE		(1 << 1)
#define  TEGRA_SDMMC_CLK_CNTL_INTERNAL_CLOCK_EN		(1 << 0)

#define  TEGRA_SDMMC_INTERRUPT_STATUS_ERR_INTERRUPT	(1 << 15)
#define  TEGRA_SDMMC_INTERRUPT_STATUS_CMD_TIMEOUT	(1 << 16)

#define TEGRA_SDMMC_INT_STAT_EN				0x034
#define  TEGRA_SDMMC_INT_STAT_EN_CMD_COMPLETE		(1 << 0)
#define  TEGRA_SDMMC_INT_STAT_EN_XFER_COMPLETE		(1 << 1)
#define  TEGRA_SDMMC_INT_STAT_EN_DMA_INTERRUPT		(1 << 3)
#define  TEGRA_SDMMC_INT_STAT_EN_BUFFER_WRITE_READY	(1 << 4)
#define  TEGRA_SDMMC_INT_STAT_EN_BUFFER_READ_READY	(1 << 5)

#define TEGRA_SDMMC_INT_SIG_EN				0x038
#define  TEGRA_SDMMC_INT_SIG_EN_XFER_COMPLETE		(1 << 1)

#define TEGRA_SDMMC_SDMEMCOMPPADCTRL			0x1e0
#define  TEGRA_SDMMC_SDMEMCOMPPADCTRL_VREF_SEL_SHIFT	0

#define TEGRA_SDMMC_AUTO_CAL_CONFIG			0x1e4
#define  TEGRA_SDMMC_AUTO_CAL_CONFIG_PU_OFFSET_SHIFT	0
#define  TEGRA_SDMMC_AUTO_CAL_CONFIG_PD_OFFSET_SHIFT	8
#define  TEGRA_SDMMC_AUTO_CAL_CONFIG_ENABLE		(1 << 29)

struct tegra_sdmmc_host {
	struct mci_host		mci;
	void __iomem		*regs;
	struct clk		*clk;
	struct reset_control	*reset;
	int			gpio_cd, gpio_pwr;
};
#define to_tegra_sdmmc_host(mci) container_of(mci, struct tegra_sdmmc_host, mci)

static int tegra_sdmmc_wait_inhibit(struct tegra_sdmmc_host *host,
				    struct mci_cmd *cmd, struct mci_data *data,
				    unsigned int timeout)
{
	u32 val = TEGRA_SDMMC_PRESENT_STATE_CMD_INHIBIT_CMD;

	/*
	 * We shouldn't wait for data inhibit for stop commands, even
	 * though they might use busy signaling
	 */
	if ((data == NULL) && (cmd->resp_type & MMC_RSP_BUSY))
		val |= TEGRA_SDMMC_PRESENT_STATE_CMD_INHIBIT_DAT;

	wait_on_timeout(timeout * MSECOND,
	                !(readl(host->regs + TEGRA_SDMMC_PRESENT_STATE) & val));

	return 0;
}

static int tegra_sdmmc_send_cmd(struct mci_host *mci, struct mci_cmd *cmd,
				struct mci_data *data)
{
	struct tegra_sdmmc_host *host = to_tegra_sdmmc_host(mci);
	unsigned int num_bytes = 0;
	u32 val = 0;
	int ret;

	ret = tegra_sdmmc_wait_inhibit(host, cmd, data, 10);
	if (ret < 0)
		return ret;

	/* Set up for a data transfer if we have one */
	if (data) {
		num_bytes = data->blocks * data->blocksize;

		if (data->flags & MMC_DATA_WRITE) {
			dma_sync_single_for_device((unsigned long)data->src,
						   num_bytes, DMA_TO_DEVICE);
			writel((u32)data->src, host->regs + SDHCI_DMA_ADDRESS);
		} else {
			dma_sync_single_for_device((unsigned long)data->dest,
						   num_bytes, DMA_FROM_DEVICE);
			writel((u32)data->dest, host->regs + SDHCI_DMA_ADDRESS);
		}

		writel((7 << 12) | data->blocks << 16 | data->blocksize,
		       host->regs + SDHCI_BLOCK_SIZE__BLOCK_COUNT);
	}

	writel(cmd->cmdarg, host->regs + SDHCI_ARGUMENT);

	if ((cmd->resp_type & MMC_RSP_136) && (cmd->resp_type & MMC_RSP_BUSY))
		return -1;

	if (data) {
		if (data->blocks > 1)
			val |= TRANSFER_MODE_MSBSEL;

		if (data->flags & MMC_DATA_READ)
			val |= TRANSFER_MODE_DTDSEL;

		val |= TRANSFER_MODE_DMAEN | TRANSFER_MODE_BCEN;
	}

	if (!(cmd->resp_type & MMC_RSP_PRESENT))
		val |= COMMAND_RSPTYP_NONE;
	else if (cmd->resp_type & MMC_RSP_136)
		val |= COMMAND_RSPTYP_136;
	else if (cmd->resp_type & MMC_RSP_BUSY)
		val |= COMMAND_RSPTYP_48_BUSY;
	else
		val |= COMMAND_RSPTYP_48;

	if (cmd->resp_type & MMC_RSP_CRC)
		val |= COMMAND_CCCEN;
	if (cmd->resp_type & MMC_RSP_OPCODE)
		val |= COMMAND_CICEN;

	if (data)
		val |= COMMAND_DPSEL;

	writel(COMMAND_CMD(cmd->cmdidx) | val,
		host->regs + SDHCI_TRANSFER_MODE__COMMAND);

	ret = wait_on_timeout(100 * MSECOND,
			(val = readl(host->regs + SDHCI_INT_STATUS))
			& IRQSTAT_CC);

	if (ret) {
		writel(val, host->regs + SDHCI_INT_STATUS);
		return ret;
	}

	if ((val & IRQSTAT_CC) && !data)
		writel(val, host->regs + SDHCI_INT_STATUS);

	if (val & TEGRA_SDMMC_INTERRUPT_STATUS_CMD_TIMEOUT) {
		/* Timeout Error */
		dev_dbg(mci->hw_dev, "timeout: %08x cmd %d\n", val, cmd->cmdidx);
		writel(val, host->regs + SDHCI_INT_STATUS);
		return -ETIMEDOUT;
	} else if (val & TEGRA_SDMMC_INTERRUPT_STATUS_ERR_INTERRUPT) {
		/* Error Interrupt */
		dev_dbg(mci->hw_dev, "error: %08x cmd %d\n", val, cmd->cmdidx);
		writel(val, host->regs + SDHCI_INT_STATUS);
		return -EIO;
	}

	if (cmd->resp_type & MMC_RSP_PRESENT) {
		if (cmd->resp_type & MMC_RSP_136) {
			u32 cmdrsp[4];

			cmdrsp[3] = readl(host->regs + SDHCI_RESPONSE_3);
			cmdrsp[2] = readl(host->regs + SDHCI_RESPONSE_2);
			cmdrsp[1] = readl(host->regs + SDHCI_RESPONSE_1);
			cmdrsp[0] = readl(host->regs + SDHCI_RESPONSE_0);
			cmd->response[0] = (cmdrsp[3] << 8) | (cmdrsp[2] >> 24);
			cmd->response[1] = (cmdrsp[2] << 8) | (cmdrsp[1] >> 24);
			cmd->response[2] = (cmdrsp[1] << 8) | (cmdrsp[0] >> 24);
			cmd->response[3] = (cmdrsp[0] << 8);
		} else if (cmd->resp_type & MMC_RSP_BUSY) {
			ret = wait_on_timeout(100 * MSECOND,
				readl(host->regs + TEGRA_SDMMC_PRESENT_STATE)
				& (1 << 20));

			if (ret) {
				dev_err(mci->hw_dev, "card is still busy\n");
				writel(val, host->regs + SDHCI_INT_STATUS);
				return ret;
			}

			cmd->response[0] = readl(host->regs + SDHCI_RESPONSE_0);
		} else {
			cmd->response[0] = readl(host->regs + SDHCI_RESPONSE_0);
		}
	}

	if (data) {
		uint64_t start = get_time_ns();

		while (1) {
			val = readl(host->regs + SDHCI_INT_STATUS);

			if (val & TEGRA_SDMMC_INTERRUPT_STATUS_ERR_INTERRUPT) {
				/* Error Interrupt */
				writel(val, host->regs + SDHCI_INT_STATUS);
				dev_err(mci->hw_dev,
					"error during transfer: 0x%08x\n", val);
				return -EIO;
			} else if (val & IRQSTAT_DINT) {
				/*
				 * DMA Interrupt, restart the transfer where
				 * it was interrupted.
				 */
				u32 address = readl(host->regs +
						    SDHCI_DMA_ADDRESS);

				writel(IRQSTAT_DINT,
				       host->regs + SDHCI_INT_STATUS);
				writel(address, host->regs + SDHCI_DMA_ADDRESS);
			} else if (val & IRQSTAT_TC) {
				/* Transfer Complete */;
				break;
			} else if (is_timeout(start, 2 * SECOND)) {
				writel(val, host->regs + SDHCI_INT_STATUS);
				dev_err(mci->hw_dev, "MMC Timeout\n"
					"    Interrupt status        0x%08x\n"
					"    Interrupt status enable 0x%08x\n"
					"    Interrupt signal enable 0x%08x\n"
					"    Present status          0x%08x\n",
					val,
					readl(host->regs + SDHCI_INT_ENABLE),
					readl(host->regs + SDHCI_SIGNAL_ENABLE),
					readl(host->regs + SDHCI_PRESENT_STATE));
				return -ETIMEDOUT;
			}
		}
		writel(val, host->regs + SDHCI_INT_STATUS);

		if (data->flags & MMC_DATA_WRITE)
			dma_sync_single_for_cpu((unsigned long)data->src,
						num_bytes, DMA_TO_DEVICE);
		else
			dma_sync_single_for_cpu((unsigned long)data->dest,
						num_bytes, DMA_FROM_DEVICE);
	}

	return 0;
}

static void tegra_sdmmc_set_clock(struct tegra_sdmmc_host *host, u32 clock)
{
	u32 prediv = 1, adjusted_clock = clock, val;

	while (adjusted_clock < 3200000) {
		prediv *= 2;
		adjusted_clock = clock * prediv * 2;
	}

	/* clear clock related bits */
	val = readl(host->regs + TEGRA_SDMMC_CLK_CNTL);
	val &= 0xffff0000;
	writel(val, host->regs + TEGRA_SDMMC_CLK_CNTL);

	/* set new frequency */
	val |= prediv << 8;
	val |= TEGRA_SDMMC_CLK_CNTL_INTERNAL_CLOCK_EN;
	writel(val, host->regs + TEGRA_SDMMC_CLK_CNTL);

	clk_set_rate(host->clk, adjusted_clock);

	/* wait for controller to settle */
	wait_on_timeout(10 * MSECOND,
			!(readl(host->regs + TEGRA_SDMMC_CLK_CNTL) &
			  TEGRA_SDMMC_CLK_INTERNAL_CLOCK_STABLE));

	/* enable card clock */
	val |= TEGRA_SDMMC_CLK_CNTL_SD_CLOCK_EN;
	writel(val, host->regs + TEGRA_SDMMC_CLK_CNTL);
}

static void tegra_sdmmc_set_ios(struct mci_host *mci, struct mci_ios *ios)
{
	struct tegra_sdmmc_host *host = to_tegra_sdmmc_host(mci);
	u32 val;

	/* set clock */
	if (ios->clock)
		tegra_sdmmc_set_clock(host, ios->clock);

	/* set bus width */
	val = readl(host->regs + TEGRA_SDMMC_PWR_CNTL);
	val &= ~(0x21);

	if (ios->bus_width == MMC_BUS_WIDTH_8)
		val |= (1 << 5);
	else if (ios->bus_width == MMC_BUS_WIDTH_4)
		val |= (1 << 1);

	writel(val, host->regs + TEGRA_SDMMC_PWR_CNTL);
}

static int tegra_sdmmc_init(struct mci_host *mci, struct device_d *dev)
{
	struct tegra_sdmmc_host *host = to_tegra_sdmmc_host(mci);
	void __iomem *regs = host->regs;
	u32 val;
	int ret;

	/* reset controller */
	writel(TEGRA_SDMMC_CLK_CNTL_SW_RESET_FOR_ALL,
		regs + TEGRA_SDMMC_CLK_CNTL);

	ret = wait_on_timeout(100 * MSECOND,
			!(readl(regs + TEGRA_SDMMC_CLK_CNTL) &
			 TEGRA_SDMMC_CLK_CNTL_SW_RESET_FOR_ALL));
	if (ret) {
		dev_err(dev, "timeout while reset\n");
		return ret;
	}

	/* set power */
	val = readl(regs + TEGRA_SDMMC_PWR_CNTL);
	val &= ~(0xff << 8);
	val |= TEGRA_SDMMC_PWR_CNTL_33_V | TEGRA_SDMMC_PWR_CNTL_SD_BUS;
	writel(val, regs + TEGRA_SDMMC_PWR_CNTL);

	/* sdmmc1 and sdmmc3 on T30 need a bit of padctrl init */
	if (of_device_is_compatible(mci->hw_dev->device_node,
			"nvidia,tegra30-sdhci") &&
			((u32)regs == 0x78000000 || (u32)regs == 78000400)) {
		val = readl(regs + TEGRA_SDMMC_SDMEMCOMPPADCTRL);
		val &= 0xfffffff0;
		val |= 0x7 << TEGRA_SDMMC_SDMEMCOMPPADCTRL_VREF_SEL_SHIFT;
		writel(val, regs + TEGRA_SDMMC_SDMEMCOMPPADCTRL);

		val = readl(regs + TEGRA_SDMMC_AUTO_CAL_CONFIG);
		val &= 0xffff0000;
		val |= (0x62 << TEGRA_SDMMC_AUTO_CAL_CONFIG_PU_OFFSET_SHIFT) |
		       (0x70 << TEGRA_SDMMC_AUTO_CAL_CONFIG_PD_OFFSET_SHIFT) |
		       TEGRA_SDMMC_AUTO_CAL_CONFIG_ENABLE;
		writel(val, regs + TEGRA_SDMMC_AUTO_CAL_CONFIG);
	}

	/* setup signaling */
	writel(0xffffffff, regs + TEGRA_SDMMC_INT_STAT_EN);
	writel(0xffffffff, regs + TEGRA_SDMMC_INT_SIG_EN);

	writel(0xe << 16, regs + TEGRA_SDMMC_CLK_CNTL);

	val = readl(regs + TEGRA_SDMMC_INT_STAT_EN);
	val &= ~(0xffff);
	val |= (TEGRA_SDMMC_INT_STAT_EN_CMD_COMPLETE |
		TEGRA_SDMMC_INT_STAT_EN_XFER_COMPLETE |
		TEGRA_SDMMC_INT_STAT_EN_DMA_INTERRUPT |
		TEGRA_SDMMC_INT_STAT_EN_BUFFER_WRITE_READY |
		TEGRA_SDMMC_INT_STAT_EN_BUFFER_READ_READY);
	writel(val, regs + TEGRA_SDMMC_INT_STAT_EN);

	val = readl(regs + TEGRA_SDMMC_INT_SIG_EN);
	val &= ~(0xffff);
	val |= TEGRA_SDMMC_INT_SIG_EN_XFER_COMPLETE;
	writel(val, regs + TEGRA_SDMMC_INT_SIG_EN);

	tegra_sdmmc_set_clock(host, 400000);

	return 0;
}

static int tegra_sdmmc_card_present(struct mci_host *mci)
{
	struct tegra_sdmmc_host *host = to_tegra_sdmmc_host(mci);
	int ret;

	if (gpio_is_valid(host->gpio_cd)) {
		ret = gpio_direction_input(host->gpio_cd);
		if (ret)
			return 0;
		return gpio_get_value(host->gpio_cd) ? 0 : 1;
	}

	return !(readl(host->regs + SDHCI_PRESENT_STATE) & PRSSTAT_WPSPL);
}

static int tegra_sdmmc_detect(struct device_d *dev)
{
	struct tegra_sdmmc_host *host = dev->priv;

	return mci_detect_card(&host->mci);
}

static void tegra_sdmmc_parse_dt(struct tegra_sdmmc_host *host)
{
	struct device_node *np = host->mci.hw_dev->device_node;
	const char *alias = of_alias_get(np);

	if (alias)
		host->mci.devname = xstrdup(alias);
	host->gpio_cd = of_get_named_gpio(np, "cd-gpios", 0);
	host->gpio_pwr = of_get_named_gpio(np, "power-gpios", 0);
	mci_of_parse(&host->mci);
}

static int tegra_sdmmc_probe(struct device_d *dev)
{
	struct resource *iores;
	struct tegra_sdmmc_host *host;
	struct mci_host *mci;
	int ret;

	host = xzalloc(sizeof(*host));
	mci = &host->mci;

	host->clk = clk_get(dev, NULL);
	if (IS_ERR(host->clk))
		return PTR_ERR(host->clk);

	host->reset = reset_control_get(dev, NULL);
	if (IS_ERR(host->reset))
		return PTR_ERR(host->reset);

	iores = dev_request_mem_resource(dev, 0);
	if (IS_ERR(iores)) {
		dev_err(dev, "could not get iomem region\n");
		return PTR_ERR(iores);
	}
	host->regs = IOMEM(iores->start);

	mci->hw_dev = dev;
	mci->f_max = 48000000;
	mci->f_min = 375000;
	tegra_sdmmc_parse_dt(host);

	if (gpio_is_valid(host->gpio_pwr)) {
		ret = gpio_request(host->gpio_pwr, "tegra_sdmmc_power");
		if (ret) {
			dev_err(dev, "failed to allocate power gpio\n");
			return -ENODEV;
		}
		gpio_direction_output(host->gpio_pwr, 1);
	}

	if (gpio_is_valid(host->gpio_cd)) {
		ret = gpio_request(host->gpio_cd, "tegra_sdmmc_cd");
		if (ret) {
			dev_err(dev, "failed to allocate cd gpio\n");
			return -ENODEV;
		}
		gpio_direction_input(host->gpio_cd);
	}

	clk_enable(host->clk);
	reset_control_assert(host->reset);
	udelay(2);
	reset_control_deassert(host->reset);

	mci->init = tegra_sdmmc_init;
	mci->card_present = tegra_sdmmc_card_present;
	mci->set_ios = tegra_sdmmc_set_ios;
	mci->send_cmd = tegra_sdmmc_send_cmd;
	mci->voltages = MMC_VDD_32_33 | MMC_VDD_33_34 | MMC_VDD_165_195;
	mci->host_caps |= MMC_CAP_MMC_HIGHSPEED | MMC_CAP_MMC_HIGHSPEED_52MHZ |
	                  MMC_CAP_SD_HIGHSPEED;

	dev->priv = host;
	dev->detect = tegra_sdmmc_detect;

	return mci_register(&host->mci);
}

static __maybe_unused struct of_device_id tegra_sdmmc_compatible[] = {
	{
		.compatible = "nvidia,tegra124-sdhci",
	}, {
		.compatible = "nvidia,tegra30-sdhci",
	}, {
		.compatible = "nvidia,tegra20-sdhci",
	}, {
		/* sentinel */
	}
};

static struct driver_d tegra_sdmmc_driver = {
	.name  = "tegra-sdmmc",
	.probe = tegra_sdmmc_probe,
	.of_compatible = DRV_OF_COMPAT(tegra_sdmmc_compatible),
};
device_platform_driver(tegra_sdmmc_driver);