/*
 * Marvell Dove SDHCI MCI driver
 *
 * Pengutronix, Michael Grzeschik <mgr@pengutronix.de>
 * Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * 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.
 *
 * This program is distributed in the hope that 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.
 *
 */

#include <clock.h>
#include <common.h>
#include <init.h>
#include <io.h>
#include <dma.h>
#include <malloc.h>
#include <mci.h>
#include <linux/err.h>

#include "sdhci.h"

struct dove_sdhci {
	struct mci_host mci;
	void __iomem *base;
};

#define priv_from_mci_host(h)	\
	container_of(h, struct dove_sdhci, mci);

static inline void dove_sdhci_writel(struct dove_sdhci *p, int reg, u32 val)
{
	writel(val, p->base + reg);
}

static inline void dove_sdhci_writew(struct dove_sdhci *p, int reg, u16 val)
{
	writew(val, p->base + reg);
}

static inline void dove_sdhci_writeb(struct dove_sdhci *p, int reg, u8 val)
{
	writeb(val, p->base + reg);
}

static inline u32 dove_sdhci_readl(struct dove_sdhci *p, int reg)
{
	return readl(p->base + reg);
}

static inline u16 dove_sdhci_readw(struct dove_sdhci *p, int reg)
{
	return readw(p->base + reg);
}

static inline u8 dove_sdhci_readb(struct dove_sdhci *p, int reg)
{
	return readb(p->base + reg);
}

static int dove_sdhci_wait_for_done(struct dove_sdhci *host, u16 mask)
{
	u16 status;
	u64 start;

	start = get_time_ns();
	while (1) {
		status = dove_sdhci_readw(host, SDHCI_INT_NORMAL_STATUS);
		if (status & SDHCI_INT_ERROR)
			return -EPERM;
		/* this special quirk is necessary, as the dma
		 * engine stops on dma boundary and will only
		 * restart after acknowledging it this way.
		 */
		if (status & SDHCI_INT_DMA) {
			u32 addr = dove_sdhci_readl(host, SDHCI_DMA_ADDRESS);
			dove_sdhci_writel(host, SDHCI_DMA_ADDRESS, addr);
		}
		if (status & mask)
			break;
		if (is_timeout(start, 1000 * MSECOND)) {
			dev_err(host->mci.hw_dev, "SDHCI timeout while waiting for done\n");
			return -ETIMEDOUT;
		}
	}
	return 0;
}

static int dove_sdhci_mci_send_cmd(struct mci_host *mci, struct mci_cmd *cmd,
				struct mci_data *data)
{
	u16 val;
	u64 start;
	int ret;
	unsigned int num_bytes = data->blocks * data->blocksize;
	struct dove_sdhci *host = priv_from_mci_host(mci);

	dove_sdhci_writel(host, SDHCI_INT_STATUS, ~0);

	/* Do not wait for CMD_INHIBIT_DAT on stop commands */
	if (cmd->cmdidx == MMC_CMD_STOP_TRANSMISSION)
		val = SDHCI_CMD_INHIBIT_CMD;
	else
		val = SDHCI_CMD_INHIBIT_CMD | SDHCI_CMD_INHIBIT_DATA;

	/* Wait for bus idle */
	start = get_time_ns();
	while (1) {
		if (!(dove_sdhci_readw(host, SDHCI_PRESENT_STATE) & val))
			break;
		if (is_timeout(start, 10 * MSECOND)) {
			dev_err(host->mci.hw_dev, "SDHCI timeout while waiting for idle\n");
			return -ETIMEDOUT;
		}
	}

	/* setup transfer data */
	if (data) {
		if (data->flags & MMC_DATA_READ)
			dove_sdhci_writel(host, SDHCI_DMA_ADDRESS, (u32)data->dest);
		else
			dove_sdhci_writel(host, SDHCI_DMA_ADDRESS, (u32)data->src);
		dove_sdhci_writew(host, SDHCI_BLOCK_SIZE, SDHCI_DMA_BOUNDARY_512K |
				SDHCI_TRANSFER_BLOCK_SIZE(data->blocksize));
		dove_sdhci_writew(host, SDHCI_BLOCK_COUNT, data->blocks);
		dove_sdhci_writeb(host, SDHCI_TIMEOUT_CONTROL, 0xe);


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

	/* setup transfer mode */
	val = 0;
	if (data) {
		val |= SDHCI_DMA_EN | SDHCI_BLOCK_COUNT_EN;
		if (data->blocks > 1)
			val |= SDHCI_MULTIPLE_BLOCKS;
		if (data->flags & MMC_DATA_READ)
			val |= SDHCI_DATA_TO_HOST;
	}
	dove_sdhci_writew(host, SDHCI_TRANSFER_MODE, val);

	dove_sdhci_writel(host, SDHCI_ARGUMENT, cmd->cmdarg);

	if (!(cmd->resp_type & MMC_RSP_PRESENT))
		val = SDHCI_RESP_NONE;
	else if (cmd->resp_type & MMC_RSP_136)
		val = SDHCI_RESP_TYPE_136;
	else if (cmd->resp_type & MMC_RSP_BUSY)
		val = SDHCI_RESP_TYPE_48_BUSY;
	else
		val = SDHCI_RESP_TYPE_48;

	if (cmd->resp_type & MMC_RSP_CRC)
		val |= SDHCI_CMD_CRC_CHECK_EN;
	if (cmd->resp_type & MMC_RSP_OPCODE)
		val |= SDHCI_CMD_INDEX_CHECK_EN;
	if (data)
		val |= SDHCI_DATA_PRESENT;
	val |= SDHCI_CMD_INDEX(cmd->cmdidx);

	dove_sdhci_writew(host, SDHCI_COMMAND, val);

	ret = dove_sdhci_wait_for_done(host, SDHCI_INT_CMD_COMPLETE);
	if (ret) {
		dev_err(host->mci.hw_dev, "error on command %d\n", cmd->cmdidx);
		dev_err(host->mci.hw_dev, "state = %04x %04x, interrupt = %04x %04x\n",
			dove_sdhci_readw(host, SDHCI_PRESENT_STATE),
			dove_sdhci_readw(host, SDHCI_PRESENT_STATE1),
			dove_sdhci_readw(host, SDHCI_INT_NORMAL_STATUS),
			dove_sdhci_readw(host, SDHCI_INT_ERROR_STATUS));
		goto cmd_error;
	}

	/* CRC is stripped so we need to do some shifting. */
	if (cmd->resp_type & MMC_RSP_136) {
		int i;
		for (i = 0; i < 4; i++) {
			cmd->response[i] = dove_sdhci_readl(host,
					SDHCI_RESPONSE_0 + 4*(3-i)) << 8;
			if (i != 3)
				cmd->response[i] |= dove_sdhci_readb(host,
					SDHCI_RESPONSE_0 + 4*(3-i) - 1);
		}
	} else
		cmd->response[0] = dove_sdhci_readl(host, SDHCI_RESPONSE_0);

	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);

	if (data) {
		ret = dove_sdhci_wait_for_done(host, SDHCI_INT_XFER_COMPLETE);
		if (ret) {
			dev_err(host->mci.hw_dev, "error while transfering data for command %d\n",
				cmd->cmdidx);
			dev_err(host->mci.hw_dev, "state = %04x %04x, interrupt = %04x %04x\n",
				dove_sdhci_readw(host, SDHCI_PRESENT_STATE),
				dove_sdhci_readw(host, SDHCI_PRESENT_STATE1),
				dove_sdhci_readw(host, SDHCI_INT_NORMAL_STATUS),
				dove_sdhci_readw(host, SDHCI_INT_ERROR_STATUS));
			goto cmd_error;
		}
	}

cmd_error:
	dove_sdhci_writel(host, SDHCI_INT_STATUS, ~0);
	return ret;
}

static u16 dove_sdhci_get_clock_divider(struct dove_sdhci *host, u32 reqclk)
{
	u16 div;

	for (div = 1; div < SDHCI_SPEC_200_MAX_CLK_DIVIDER; div *= 2)
		if ((host->mci.f_max / div) <= reqclk)
			break;
	div /= 2;

	return div;
}

static void dove_sdhci_mci_set_ios(struct mci_host *mci, struct mci_ios *ios)
{
	u16 val;
	u64 start;
	struct dove_sdhci *host = priv_from_mci_host(mci);

	debug("%s: clock = %u, bus-width = %d, timing = %02x\n", __func__, ios->clock, ios->bus_width, ios->timing);

	/* disable on zero clock */
	if (!ios->clock)
		return;

	/* enable bus power */
	val = SDHCI_BUS_VOLTAGE_330;
	dove_sdhci_writeb(host, SDHCI_POWER_CONTROL, val | SDHCI_BUS_POWER_EN);
	udelay(400);

	/* set bus width */
	val = dove_sdhci_readb(host, SDHCI_HOST_CONTROL) &
		~(SDHCI_DATA_WIDTH_4BIT | SDHCI_DATA_WIDTH_8BIT);
	switch (ios->bus_width) {
	case MMC_BUS_WIDTH_8:
		val |= SDHCI_DATA_WIDTH_8BIT;
		break;
	case MMC_BUS_WIDTH_4:
		val |= SDHCI_DATA_WIDTH_4BIT;
		break;
	}

	if (ios->clock > 26000000)
		val |= SDHCI_HIGHSPEED_EN;
	else
		val &= ~SDHCI_HIGHSPEED_EN;

	dove_sdhci_writeb(host, SDHCI_HOST_CONTROL, val);

	/* set bus clock */
	dove_sdhci_writew(host, SDHCI_CLOCK_CONTROL, 0);
	val = dove_sdhci_get_clock_divider(host, ios->clock);
	val = SDHCI_INTCLOCK_EN | SDHCI_FREQ_SEL(val);
	dove_sdhci_writew(host, SDHCI_CLOCK_CONTROL, val);

	/* wait for internal clock stable */
	start = get_time_ns();
	while (!(dove_sdhci_readw(host, SDHCI_CLOCK_CONTROL) &
			SDHCI_INTCLOCK_STABLE)) {
		if (is_timeout(start, 20 * MSECOND)) {
			dev_err(host->mci.hw_dev, "SDHCI clock stable timeout\n");
			return;
		}
	}

	/* enable bus clock */
	dove_sdhci_writew(host, SDHCI_CLOCK_CONTROL, val | SDHCI_SDCLOCK_EN);
}

static int dove_sdhci_mci_init(struct mci_host *mci, struct device_d *dev)
{
	u64 start;
	struct dove_sdhci *host = priv_from_mci_host(mci);

	/* reset sdhci controller */
	dove_sdhci_writeb(host, SDHCI_SOFTWARE_RESET, SDHCI_RESET_ALL);

	/* wait for reset completion */
	start = get_time_ns();
	while (1) {
		if ((dove_sdhci_readb(host, SDHCI_SOFTWARE_RESET) &
				SDHCI_RESET_ALL) == 0)
			break;
		if (is_timeout(start, 100 * MSECOND)) {
			dev_err(dev, "SDHCI reset timeout\n");
			return -ETIMEDOUT;
		}
	}

	dove_sdhci_writel(host, SDHCI_INT_STATUS, ~0);
	dove_sdhci_writel(host, SDHCI_INT_ENABLE, ~0);
	dove_sdhci_writel(host, SDHCI_SIGNAL_ENABLE, ~0);

	return 0;
}

static void dove_sdhci_set_mci_caps(struct dove_sdhci *host)
{
	u16 caps[2];

	caps[0] = dove_sdhci_readw(host, SDHCI_CAPABILITIES);
	caps[1] = dove_sdhci_readw(host, SDHCI_CAPABILITIES_1);

	if (caps[1] & SDHCI_HOSTCAP_VOLTAGE_180)
		host->mci.voltages |= MMC_VDD_165_195;
	if (caps[1] & SDHCI_HOSTCAP_VOLTAGE_300)
		host->mci.voltages |= MMC_VDD_29_30 | MMC_VDD_30_31;
	if (caps[1] & SDHCI_HOSTCAP_VOLTAGE_330)
		host->mci.voltages |= MMC_VDD_32_33 | MMC_VDD_33_34;

	if (caps[1] & SDHCI_HOSTCAP_HIGHSPEED)
		host->mci.host_caps |= (MMC_CAP_MMC_HIGHSPEED_52MHZ |
					MMC_CAP_MMC_HIGHSPEED |
					MMC_CAP_SD_HIGHSPEED);

	/* parse board supported bus width capabilities */
	mci_of_parse(&host->mci);

	/* limit bus widths to controller capabilities */
	if ((caps[1] & SDHCI_HOSTCAP_8BIT) == 0)
		host->mci.host_caps &= ~MMC_CAP_8_BIT_DATA;
}

static int dove_sdhci_detect(struct device_d *dev)
{
	struct dove_sdhci *host = dev->priv;
	return mci_detect_card(&host->mci);
}

static int dove_sdhci_probe(struct device_d *dev)
{
	struct dove_sdhci *host;
	int ret;

	host = xzalloc(sizeof(*host));
	host->base = dev_request_mem_region(dev, 0);
	host->mci.max_req_size = 0x8000;
	host->mci.hw_dev = dev;
	host->mci.send_cmd = dove_sdhci_mci_send_cmd;
	host->mci.set_ios = dove_sdhci_mci_set_ios;
	host->mci.init = dove_sdhci_mci_init;
	host->mci.f_max = 50000000;
	host->mci.f_min = host->mci.f_max / 256;
	dev->priv = host;
	dev->detect = dove_sdhci_detect;

	dove_sdhci_set_mci_caps(host);

	ret = mci_register(&host->mci);
	if (ret)
		free(host);
	return ret;
}

static struct of_device_id dove_sdhci_dt_ids[] = {
	{ .compatible = "marvell,dove-sdhci", },
	{ }
};

static struct driver_d dove_sdhci_driver = {
	.name = "dove-sdhci",
	.probe = dove_sdhci_probe,
	.of_compatible = DRV_OF_COMPAT(dove_sdhci_dt_ids),
};
device_platform_driver(dove_sdhci_driver);