/*
 * Copyright (c) 2013 Google, Inc
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

#include <common.h>
#include <clk.h>
#include <dm.h>
#include <dt-structs.h>
#include <dwmmc.h>
#include <errno.h>
#include <mapmem.h>
#include <pwrseq.h>
#include <syscon.h>
#include <asm/gpio.h>
#include <asm/arch/clock.h>
#include <asm/arch/periph.h>
#include <linux/err.h>

DECLARE_GLOBAL_DATA_PTR;

struct rockchip_mmc_plat {
#if CONFIG_IS_ENABLED(OF_PLATDATA)
	struct dtd_rockchip_rk3288_dw_mshc dtplat;
#endif
	struct mmc_config cfg;
	struct mmc mmc;
};

struct rockchip_dwmmc_priv {
	struct clk clk;
	struct clk sample_clk;
	struct dwmci_host host;
	int fifo_depth;
	bool fifo_mode;
	u32 minmax[2];
};

static uint rockchip_dwmmc_get_mmc_clk(struct dwmci_host *host, uint freq)
{
	struct udevice *dev = host->priv;
	struct rockchip_dwmmc_priv *priv = dev_get_priv(dev);
	int ret;

	/*
	 * If DDR52 8bit mode(only emmc work in 8bit mode),
	 * divider must be set 1
	 */
	if (mmc_card_ddr52(host->mmc) && host->mmc->bus_width == 8)
		freq *= 2;

	ret = clk_set_rate(&priv->clk, freq);
	if (ret < 0) {
		debug("%s: err=%d\n", __func__, ret);
		return ret;
	}

	return freq;
}

static int rockchip_dwmmc_ofdata_to_platdata(struct udevice *dev)
{
#if !CONFIG_IS_ENABLED(OF_PLATDATA)
	struct rockchip_dwmmc_priv *priv = dev_get_priv(dev);
	struct dwmci_host *host = &priv->host;

	host->name = dev->name;
	host->ioaddr = dev_read_addr_ptr(dev);
	host->buswidth = dev_read_u32_default(dev, "bus-width", 4);
	host->get_mmc_clk = rockchip_dwmmc_get_mmc_clk;
	host->priv = dev;

	/* use non-removeable as sdcard and emmc as judgement */
	if (dev_read_bool(dev, "non-removable"))
		host->dev_index = 0;
	else
		host->dev_index = 1;

	priv->fifo_depth = dev_read_u32_default(dev, "fifo-depth", 0);

	if (priv->fifo_depth < 0)
		return -EINVAL;
	priv->fifo_mode = dev_read_bool(dev, "fifo-mode");

	/*
	 * 'clock-freq-min-max' is deprecated
	 * (see https://github.com/torvalds/linux/commit/b023030f10573de738bbe8df63d43acab64c9f7b)
	 */
	if (dev_read_u32_array(dev, "clock-freq-min-max", priv->minmax, 2)) {
		int val = dev_read_u32_default(dev, "max-frequency", -EINVAL);

		if (val < 0)
			return val;

		priv->minmax[0] = 400000;  /* 400 kHz */
		priv->minmax[1] = val;
	} else {
		debug("%s: 'clock-freq-min-max' property was deprecated.\n",
		      __func__);
	}
#endif
	return 0;
}

#define NUM_PHASES			270
#define TUNING_ITERATION_TO_PHASE(i)	(DIV_ROUND_UP((i) * 270, NUM_PHASES))

static int rockchip_dwmmc_execute_tuning(struct dwmci_host *host, u32 opcode)
{
	int ret = 0;
	int i;
	bool v, prev_v = 0, first_v;
	struct range_t {
		int start;
		int end; /* inclusive */
	};
	struct range_t *ranges;
	unsigned int range_count = 0;
	int longest_range_len = -1;
	int longest_range = -1;
	int middle_phase;
	struct udevice *dev = host->priv;
	struct rockchip_dwmmc_priv *priv = dev_get_priv(dev);
	struct mmc *mmc = host->mmc;

	if (IS_ERR(&priv->sample_clk))
		return -EIO;

	ranges = calloc(sizeof(*ranges), NUM_PHASES / 2 + 1);
	if (!ranges)
		return -ENOMEM;

	/* Try each phase and extract good ranges */
	for (i = 0; i < NUM_PHASES; ) {
		clk_set_phase(&priv->sample_clk, TUNING_ITERATION_TO_PHASE(i));

		v = !mmc_send_tuning(mmc, opcode);

		if (i == 0)
			first_v = v;

		if ((!prev_v) && v) {
			range_count++;
			ranges[range_count - 1].start = i;
		}
		if (v) {
			ranges[range_count - 1].end = i;
			i++;
		} else if (i == NUM_PHASES - 1) {
			/* No extra skipping rules if we're at the end */
			i++;
		} else {
			/*
			 * No need to check too close to an invalid
			 * one since testing bad phases is slow.  Skip
			 * 20 degrees.
			 */
			i += DIV_ROUND_UP(20 * NUM_PHASES, NUM_PHASES);

			/* Always test the last one */
			if (i >= NUM_PHASES)
				i = NUM_PHASES - 1;
		}

		prev_v = v;
	}

	if (range_count == 0) {
		debug("All phases bad!");
		ret = -EIO;
		goto free;
	}

	/* wrap around case, merge the end points */
	if ((range_count > 1) && first_v && v) {
		ranges[0].start = ranges[range_count - 1].start;
		range_count--;
	}

	if (ranges[0].start == 0 && ranges[0].end == NUM_PHASES - 1) {
		clk_set_phase(&priv->sample_clk,
			      TUNING_ITERATION_TO_PHASE(NUM_PHASES / 2));
		debug("All phases work, using middle phase.\n");
		goto free;
	}

	/* Find the longest range */
	for (i = 0; i < range_count; i++) {
		int len = (ranges[i].end - ranges[i].start + 1);

		if (len < 0)
			len += NUM_PHASES;

		if (longest_range_len < len) {
			longest_range_len = len;
			longest_range = i;
		}

		debug("Good phase range %d-%d (%d len)\n",
		      TUNING_ITERATION_TO_PHASE(ranges[i].start),
		      TUNING_ITERATION_TO_PHASE(ranges[i].end), len);
	}

	printf("Best phase range %d-%d (%d len)\n",
	       TUNING_ITERATION_TO_PHASE(ranges[longest_range].start),
	       TUNING_ITERATION_TO_PHASE(ranges[longest_range].end),
	       longest_range_len);

	middle_phase = ranges[longest_range].start + longest_range_len / 2;
	middle_phase %= NUM_PHASES;
	debug("Successfully tuned phase to %d\n",
	      TUNING_ITERATION_TO_PHASE(middle_phase));

	clk_set_phase(&priv->sample_clk,
		      TUNING_ITERATION_TO_PHASE(middle_phase));

free:
	free(ranges);
	return ret;
}

static int rockchip_dwmmc_probe(struct udevice *dev)
{
	struct rockchip_mmc_plat *plat = dev_get_platdata(dev);
	struct mmc_uclass_priv *upriv = dev_get_uclass_priv(dev);
	struct rockchip_dwmmc_priv *priv = dev_get_priv(dev);
	struct dwmci_host *host = &priv->host;
	struct udevice *pwr_dev __maybe_unused;
	int ret;

#if CONFIG_IS_ENABLED(OF_PLATDATA)
	struct dtd_rockchip_rk3288_dw_mshc *dtplat = &plat->dtplat;

	host->name = dev->name;
	host->ioaddr = map_sysmem(dtplat->reg[0], dtplat->reg[1]);
	host->buswidth = dtplat->bus_width;
	host->get_mmc_clk = rockchip_dwmmc_get_mmc_clk;
	host->execute_tuning = rockchip_dwmmc_execute_tuning;
	host->priv = dev;
	host->dev_index = 0;
	priv->fifo_depth = dtplat->fifo_depth;
	priv->fifo_mode = 0;
	priv->minmax[0] = 400000;  /*  400 kHz */
	priv->minmax[1] = dtplat->max_frequency;

	ret = clk_get_by_index_platdata(dev, 0, dtplat->clocks, &priv->clk);
	if (ret < 0)
		return ret;
#else
	ret = clk_get_by_index(dev, 0, &priv->clk);
	if (ret < 0)
		return ret;
	clk_get_by_name(dev, "ciu_sample", &priv->sample_clk);
	host->execute_tuning = rockchip_dwmmc_execute_tuning;
#endif
	host->fifoth_val = MSIZE(0x2) |
		RX_WMARK(priv->fifo_depth / 2 - 1) |
		TX_WMARK(priv->fifo_depth / 2);

	host->fifo_mode = priv->fifo_mode;

#ifdef CONFIG_ROCKCHIP_RK3128
	host->stride_pio = true;
#else
	host->stride_pio = false;
#endif

#ifdef CONFIG_PWRSEQ
	/* Enable power if needed */
	ret = uclass_get_device_by_phandle(UCLASS_PWRSEQ, dev, "mmc-pwrseq",
					   &pwr_dev);
	if (!ret) {
		ret = pwrseq_set_power(pwr_dev, true);
		if (ret)
			return ret;
	}
#endif
	dwmci_setup_cfg(&plat->cfg, host, priv->minmax[1], priv->minmax[0]);
	plat->cfg.host_caps |= MMC_MODE_DDR_52MHz;
	host->mmc = &plat->mmc;
	host->mmc->priv = &priv->host;
	host->mmc->dev = dev;
	upriv->mmc = host->mmc;

	return dwmci_probe(dev);
}

static int rockchip_dwmmc_bind(struct udevice *dev)
{
	struct rockchip_mmc_plat *plat = dev_get_platdata(dev);

	return dwmci_bind(dev, &plat->mmc, &plat->cfg);
}

static const struct udevice_id rockchip_dwmmc_ids[] = {
	{ .compatible = "rockchip,rk3288-dw-mshc" },
	{ .compatible = "rockchip,rk2928-dw-mshc" },
	{ }
};

U_BOOT_DRIVER(rockchip_dwmmc_drv) = {
	.name		= "rockchip_rk3288_dw_mshc",
	.id		= UCLASS_MMC,
	.of_match	= rockchip_dwmmc_ids,
	.ofdata_to_platdata = rockchip_dwmmc_ofdata_to_platdata,
	.ops		= &dm_dwmci_ops,
	.bind		= rockchip_dwmmc_bind,
	.probe		= rockchip_dwmmc_probe,
	.priv_auto_alloc_size = sizeof(struct rockchip_dwmmc_priv),
	.platdata_auto_alloc_size = sizeof(struct rockchip_mmc_plat),
};

#ifdef CONFIG_PWRSEQ
static int rockchip_dwmmc_pwrseq_set_power(struct udevice *dev, bool enable)
{
	struct gpio_desc reset;
	int ret;

	ret = gpio_request_by_name(dev, "reset-gpios", 0, &reset, GPIOD_IS_OUT);
	if (ret)
		return ret;
	dm_gpio_set_value(&reset, 1);
	udelay(1);
	dm_gpio_set_value(&reset, 0);
	udelay(200);

	return 0;
}

static const struct pwrseq_ops rockchip_dwmmc_pwrseq_ops = {
	.set_power	= rockchip_dwmmc_pwrseq_set_power,
};

static const struct udevice_id rockchip_dwmmc_pwrseq_ids[] = {
	{ .compatible = "mmc-pwrseq-emmc" },
	{ }
};

U_BOOT_DRIVER(rockchip_dwmmc_pwrseq_drv) = {
	.name		= "mmc_pwrseq_emmc",
	.id		= UCLASS_PWRSEQ,
	.of_match	= rockchip_dwmmc_pwrseq_ids,
	.ops		= &rockchip_dwmmc_pwrseq_ops,
};
#endif