path: root/drivers/mmc/host/sdhci-of-dwcmshc.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Driver for Synopsys DesignWare Cores Mobile Storage Host Controller
 *
 * Copyright (C) 2018 Synaptics Incorporated
 *
 * Author: Jisheng Zhang <jszhang@kernel.org>
 */

#include <linux/clk.h>
#include <linux/dma-mapping.h>
#include <linux/iopoll.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/sizes.h>

#include "sdhci-pltfm.h"

#define SDHCI_DWCMSHC_ARG2_STUFF	GENMASK(31, 16)

/* DWCMSHC specific Mode Select value */
#define DWCMSHC_CTRL_HS400		0x7

/* DWC IP vendor area 1 pointer */
#define DWCMSHC_P_VENDOR_AREA1		0xe8
#define DWCMSHC_AREA1_MASK		GENMASK(11, 0)
/* Offset inside the  vendor area 1 */
#define DWCMSHC_HOST_CTRL3		0x8
#define DWCMSHC_EMMC_CONTROL		0x2c
#define DWCMSHC_ENHANCED_STROBE		BIT(8)
#define DWCMSHC_EMMC_ATCTRL		0x40

/* Rockchip specific Registers */
#define DWCMSHC_EMMC_DLL_CTRL		0x800
#define DWCMSHC_EMMC_DLL_RXCLK		0x804
#define DWCMSHC_EMMC_DLL_TXCLK		0x808
#define DWCMSHC_EMMC_DLL_STRBIN		0x80c
#define DLL_STRBIN_TAPNUM_FROM_SW	BIT(24)
#define DWCMSHC_EMMC_DLL_STATUS0	0x840
#define DWCMSHC_EMMC_DLL_START		BIT(0)
#define DWCMSHC_EMMC_DLL_LOCKED		BIT(8)
#define DWCMSHC_EMMC_DLL_TIMEOUT	BIT(9)
#define DWCMSHC_EMMC_DLL_RXCLK_SRCSEL	29
#define DWCMSHC_EMMC_DLL_START_POINT	16
#define DWCMSHC_EMMC_DLL_INC		8
#define DWCMSHC_EMMC_DLL_DLYENA		BIT(27)
#define DLL_TXCLK_TAPNUM_DEFAULT	0x8
#define DLL_STRBIN_TAPNUM_DEFAULT	0x8
#define DLL_TXCLK_TAPNUM_FROM_SW	BIT(24)
#define DLL_RXCLK_NO_INVERTER		1
#define DLL_RXCLK_INVERTER		0
#define DLL_LOCK_WO_TMOUT(x) \
	((((x) & DWCMSHC_EMMC_DLL_LOCKED) == DWCMSHC_EMMC_DLL_LOCKED) && \
	(((x) & DWCMSHC_EMMC_DLL_TIMEOUT) == 0))
#define RK3568_MAX_CLKS 3

#define BOUNDARY_OK(addr, len) \
	((addr | (SZ_128M - 1)) == ((addr + len - 1) | (SZ_128M - 1)))

struct rk3568_priv {
	/* Rockchip specified optional clocks */
	struct clk_bulk_data rockchip_clks[RK3568_MAX_CLKS];
	u8 txclk_tapnum;
};

struct dwcmshc_priv {
	struct clk	*bus_clk;
	int vendor_specific_area1; /* P_VENDOR_SPECIFIC_AREA reg */
	void *priv; /* pointer to SoC private stuff */
};

/*
 * If DMA addr spans 128MB boundary, we split the DMA transfer into two
 * so that each DMA transfer doesn't exceed the boundary.
 */
static void dwcmshc_adma_write_desc(struct sdhci_host *host, void **desc,
				    dma_addr_t addr, int len, unsigned int cmd)
{
	int tmplen, offset;

	if (likely(!len || BOUNDARY_OK(addr, len))) {
		sdhci_adma_write_desc(host, desc, addr, len, cmd);
		return;
	}

	offset = addr & (SZ_128M - 1);
	tmplen = SZ_128M - offset;
	sdhci_adma_write_desc(host, desc, addr, tmplen, cmd);

	addr += tmplen;
	len -= tmplen;
	sdhci_adma_write_desc(host, desc, addr, len, cmd);
}

static void dwcmshc_check_auto_cmd23(struct mmc_host *mmc,
				     struct mmc_request *mrq)
{
	struct sdhci_host *host = mmc_priv(mmc);

	/*
	 * No matter V4 is enabled or not, ARGUMENT2 register is 32-bit
	 * block count register which doesn't support stuff bits of
	 * CMD23 argument on dwcmsch host controller.
	 */
	if (mrq->sbc && (mrq->sbc->arg & SDHCI_DWCMSHC_ARG2_STUFF))
		host->flags &= ~SDHCI_AUTO_CMD23;
	else
		host->flags |= SDHCI_AUTO_CMD23;
}

static void dwcmshc_request(struct mmc_host *mmc, struct mmc_request *mrq)
{
	dwcmshc_check_auto_cmd23(mmc, mrq);

	sdhci_request(mmc, mrq);
}

static void dwcmshc_set_uhs_signaling(struct sdhci_host *host,
				      unsigned int timing)
{
	u16 ctrl_2;

	ctrl_2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
	/* Select Bus Speed Mode for host */
	ctrl_2 &= ~SDHCI_CTRL_UHS_MASK;
	if ((timing == MMC_TIMING_MMC_HS200) ||
	    (timing == MMC_TIMING_UHS_SDR104))
		ctrl_2 |= SDHCI_CTRL_UHS_SDR104;
	else if (timing == MMC_TIMING_UHS_SDR12)
		ctrl_2 |= SDHCI_CTRL_UHS_SDR12;
	else if ((timing == MMC_TIMING_UHS_SDR25) ||
		 (timing == MMC_TIMING_MMC_HS))
		ctrl_2 |= SDHCI_CTRL_UHS_SDR25;
	else if (timing == MMC_TIMING_UHS_SDR50)
		ctrl_2 |= SDHCI_CTRL_UHS_SDR50;
	else if ((timing == MMC_TIMING_UHS_DDR50) ||
		 (timing == MMC_TIMING_MMC_DDR52))
		ctrl_2 |= SDHCI_CTRL_UHS_DDR50;
	else if (timing == MMC_TIMING_MMC_HS400)
		ctrl_2 |= DWCMSHC_CTRL_HS400;
	sdhci_writew(host, ctrl_2, SDHCI_HOST_CONTROL2);
}

static void dwcmshc_hs400_enhanced_strobe(struct mmc_host *mmc,
					  struct mmc_ios *ios)
{
	u32 vendor;
	struct sdhci_host *host = mmc_priv(mmc);
	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
	struct dwcmshc_priv *priv = sdhci_pltfm_priv(pltfm_host);
	int reg = priv->vendor_specific_area1 + DWCMSHC_EMMC_CONTROL;

	vendor = sdhci_readl(host, reg);
	if (ios->enhanced_strobe)
		vendor |= DWCMSHC_ENHANCED_STROBE;
	else
		vendor &= ~DWCMSHC_ENHANCED_STROBE;

	sdhci_writel(host, vendor, reg);
}

static void dwcmshc_rk3568_set_clock(struct sdhci_host *host, unsigned int clock)
{
	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
	struct dwcmshc_priv *dwc_priv = sdhci_pltfm_priv(pltfm_host);
	struct rk3568_priv *priv = dwc_priv->priv;
	u8 txclk_tapnum = DLL_TXCLK_TAPNUM_DEFAULT;
	u32 extra, reg;
	int err;

	host->mmc->actual_clock = 0;

	/*
	 * DO NOT TOUCH THIS SETTING. RX clk inverter unit is enabled
	 * by default, but it shouldn't be enabled. We should anyway
	 * disable it before issuing any cmds.
	 */
	extra = DWCMSHC_EMMC_DLL_DLYENA |
		DLL_RXCLK_NO_INVERTER << DWCMSHC_EMMC_DLL_RXCLK_SRCSEL;
	sdhci_writel(host, extra, DWCMSHC_EMMC_DLL_RXCLK);

	if (clock == 0)
		return;

	/* Rockchip platform only support 375KHz for identify mode */
	if (clock <= 400000)
		clock = 375000;

	err = clk_set_rate(pltfm_host->clk, clock);
	if (err)
		dev_err(mmc_dev(host->mmc), "fail to set clock %d", clock);

	sdhci_set_clock(host, clock);

	/* Disable cmd conflict check */
	reg = dwc_priv->vendor_specific_area1 + DWCMSHC_HOST_CTRL3;
	extra = sdhci_readl(host, reg);
	extra &= ~BIT(0);
	sdhci_writel(host, extra, reg);

	if (clock <= 400000) {
		/* Disable DLL to reset sample clock */
		sdhci_writel(host, 0, DWCMSHC_EMMC_DLL_CTRL);
		return;
	}

	/* Reset DLL */
	sdhci_writel(host, BIT(1), DWCMSHC_EMMC_DLL_CTRL);
	udelay(1);
	sdhci_writel(host, 0x0, DWCMSHC_EMMC_DLL_CTRL);

	/* Init DLL settings */
	extra = 0x5 << DWCMSHC_EMMC_DLL_START_POINT |
		0x2 << DWCMSHC_EMMC_DLL_INC |
		DWCMSHC_EMMC_DLL_START;
	sdhci_writel(host, extra, DWCMSHC_EMMC_DLL_CTRL);
	err = readl_poll_timeout(host->ioaddr + DWCMSHC_EMMC_DLL_STATUS0,
				 extra, DLL_LOCK_WO_TMOUT(extra), 1,
				 500 * USEC_PER_MSEC);
	if (err) {
		dev_err(mmc_dev(host->mmc), "DLL lock timeout!\n");
		return;
	}

	extra = 0x1 << 16 | /* tune clock stop en */
		0x2 << 17 | /* pre-change delay */
		0x3 << 19;  /* post-change delay */
	sdhci_writel(host, extra, dwc_priv->vendor_specific_area1 + DWCMSHC_EMMC_ATCTRL);

	if (host->mmc->ios.timing == MMC_TIMING_MMC_HS200 ||
	    host->mmc->ios.timing == MMC_TIMING_MMC_HS400)
		txclk_tapnum = priv->txclk_tapnum;

	extra = DWCMSHC_EMMC_DLL_DLYENA |
		DLL_TXCLK_TAPNUM_FROM_SW |
		txclk_tapnum;
	sdhci_writel(host, extra, DWCMSHC_EMMC_DLL_TXCLK);

	extra = DWCMSHC_EMMC_DLL_DLYENA |
		DLL_STRBIN_TAPNUM_DEFAULT |
		DLL_STRBIN_TAPNUM_FROM_SW;
	sdhci_writel(host, extra, DWCMSHC_EMMC_DLL_STRBIN);
}

static const struct sdhci_ops sdhci_dwcmshc_ops = {
	.set_clock		= sdhci_set_clock,
	.set_bus_width		= sdhci_set_bus_width,
	.set_uhs_signaling	= dwcmshc_set_uhs_signaling,
	.get_max_clock		= sdhci_pltfm_clk_get_max_clock,
	.reset			= sdhci_reset,
	.adma_write_desc	= dwcmshc_adma_write_desc,
};

static const struct sdhci_ops sdhci_dwcmshc_rk3568_ops = {
	.set_clock		= dwcmshc_rk3568_set_clock,
	.set_bus_width		= sdhci_set_bus_width,
	.set_uhs_signaling	= dwcmshc_set_uhs_signaling,
	.get_max_clock		= sdhci_pltfm_clk_get_max_clock,
	.reset			= sdhci_reset,
	.adma_write_desc	= dwcmshc_adma_write_desc,
};

static const struct sdhci_pltfm_data sdhci_dwcmshc_pdata = {
	.ops = &sdhci_dwcmshc_ops,
	.quirks = SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN,
	.quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN,
};

static const struct sdhci_pltfm_data sdhci_dwcmshc_rk3568_pdata = {
	.ops = &sdhci_dwcmshc_rk3568_ops,
	.quirks = SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN |
		  SDHCI_QUIRK_BROKEN_TIMEOUT_VAL,
	.quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN |
		   SDHCI_QUIRK2_CLOCK_DIV_ZERO_BROKEN,
};

static int dwcmshc_rk3568_init(struct sdhci_host *host, struct dwcmshc_priv *dwc_priv)
{
	int err;
	struct rk3568_priv *priv = dwc_priv->priv;

	priv->rockchip_clks[0].id = "axi";
	priv->rockchip_clks[1].id = "block";
	priv->rockchip_clks[2].id = "timer";
	err = devm_clk_bulk_get_optional(mmc_dev(host->mmc), RK3568_MAX_CLKS,
					 priv->rockchip_clks);
	if (err) {
		dev_err(mmc_dev(host->mmc), "failed to get clocks %d\n", err);
		return err;
	}

	err = clk_bulk_prepare_enable(RK3568_MAX_CLKS, priv->rockchip_clks);
	if (err) {
		dev_err(mmc_dev(host->mmc), "failed to enable clocks %d\n", err);
		return err;
	}

	if (of_property_read_u8(mmc_dev(host->mmc)->of_node, "rockchip,txclk-tapnum",
				&priv->txclk_tapnum))
		priv->txclk_tapnum = DLL_TXCLK_TAPNUM_DEFAULT;

	/* Disable cmd conflict check */
	sdhci_writel(host, 0x0, dwc_priv->vendor_specific_area1 + DWCMSHC_HOST_CTRL3);
	/* Reset previous settings */
	sdhci_writel(host, 0, DWCMSHC_EMMC_DLL_TXCLK);
	sdhci_writel(host, 0, DWCMSHC_EMMC_DLL_STRBIN);

	return 0;
}

static const struct of_device_id sdhci_dwcmshc_dt_ids[] = {
	{
		.compatible = "rockchip,rk3568-dwcmshc",
		.data = &sdhci_dwcmshc_rk3568_pdata,
	},
	{
		.compatible = "snps,dwcmshc-sdhci",
		.data = &sdhci_dwcmshc_pdata,
	},
	{},
};
MODULE_DEVICE_TABLE(of, sdhci_dwcmshc_dt_ids);

static int dwcmshc_probe(struct platform_device *pdev)
{
	struct sdhci_pltfm_host *pltfm_host;
	struct sdhci_host *host;
	struct dwcmshc_priv *priv;
	struct rk3568_priv *rk_priv = NULL;
	const struct sdhci_pltfm_data *pltfm_data;
	int err;
	u32 extra;

	pltfm_data = of_device_get_match_data(&pdev->dev);
	if (!pltfm_data) {
		dev_err(&pdev->dev, "Error: No device match data found\n");
		return -ENODEV;
	}

	host = sdhci_pltfm_init(pdev, pltfm_data,
				sizeof(struct dwcmshc_priv));
	if (IS_ERR(host))
		return PTR_ERR(host);

	/*
	 * extra adma table cnt for cross 128M boundary handling.
	 */
	extra = DIV_ROUND_UP_ULL(dma_get_required_mask(&pdev->dev), SZ_128M);
	if (extra > SDHCI_MAX_SEGS)
		extra = SDHCI_MAX_SEGS;
	host->adma_table_cnt += extra;

	pltfm_host = sdhci_priv(host);
	priv = sdhci_pltfm_priv(pltfm_host);

	pltfm_host->clk = devm_clk_get(&pdev->dev, "core");
	if (IS_ERR(pltfm_host->clk)) {
		err = PTR_ERR(pltfm_host->clk);
		dev_err(&pdev->dev, "failed to get core clk: %d\n", err);
		goto free_pltfm;
	}
	err = clk_prepare_enable(pltfm_host->clk);
	if (err)
		goto free_pltfm;

	priv->bus_clk = devm_clk_get(&pdev->dev, "bus");
	if (!IS_ERR(priv->bus_clk))
		clk_prepare_enable(priv->bus_clk);

	err = mmc_of_parse(host->mmc);
	if (err)
		goto err_clk;

	sdhci_get_of_property(pdev);

	priv->vendor_specific_area1 =
		sdhci_readl(host, DWCMSHC_P_VENDOR_AREA1) & DWCMSHC_AREA1_MASK;

	host->mmc_host_ops.request = dwcmshc_request;
	host->mmc_host_ops.hs400_enhanced_strobe = dwcmshc_hs400_enhanced_strobe;

	if (pltfm_data == &sdhci_dwcmshc_rk3568_pdata) {
		rk_priv = devm_kzalloc(&pdev->dev, sizeof(struct rk3568_priv), GFP_KERNEL);
		if (!rk_priv)
			goto err_clk;

		priv->priv = rk_priv;

		err = dwcmshc_rk3568_init(host, priv);
		if (err)
			goto err_clk;
	}

	err = sdhci_add_host(host);
	if (err)
		goto err_clk;

	return 0;

err_clk:
	clk_disable_unprepare(pltfm_host->clk);
	clk_disable_unprepare(priv->bus_clk);
	if (rk_priv)
		clk_bulk_disable_unprepare(RK3568_MAX_CLKS,
					   rk_priv->rockchip_clks);
free_pltfm:
	sdhci_pltfm_free(pdev);
	return err;
}

static int dwcmshc_remove(struct platform_device *pdev)
{
	struct sdhci_host *host = platform_get_drvdata(pdev);
	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
	struct dwcmshc_priv *priv = sdhci_pltfm_priv(pltfm_host);
	struct rk3568_priv *rk_priv = priv->priv;

	sdhci_remove_host(host, 0);

	clk_disable_unprepare(pltfm_host->clk);
	clk_disable_unprepare(priv->bus_clk);
	if (rk_priv)
		clk_bulk_disable_unprepare(RK3568_MAX_CLKS,
					   rk_priv->rockchip_clks);
	sdhci_pltfm_free(pdev);

	return 0;
}

#ifdef CONFIG_PM_SLEEP
static int dwcmshc_suspend(struct device *dev)
{
	struct sdhci_host *host = dev_get_drvdata(dev);
	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
	struct dwcmshc_priv *priv = sdhci_pltfm_priv(pltfm_host);
	struct rk3568_priv *rk_priv = priv->priv;
	int ret;

	ret = sdhci_suspend_host(host);
	if (ret)
		return ret;

	clk_disable_unprepare(pltfm_host->clk);
	if (!IS_ERR(priv->bus_clk))
		clk_disable_unprepare(priv->bus_clk);

	if (rk_priv)
		clk_bulk_disable_unprepare(RK3568_MAX_CLKS,
					   rk_priv->rockchip_clks);

	return ret;
}

static int dwcmshc_resume(struct device *dev)
{
	struct sdhci_host *host = dev_get_drvdata(dev);
	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
	struct dwcmshc_priv *priv = sdhci_pltfm_priv(pltfm_host);
	struct rk3568_priv *rk_priv = priv->priv;
	int ret;

	ret = clk_prepare_enable(pltfm_host->clk);
	if (ret)
		return ret;

	if (!IS_ERR(priv->bus_clk)) {
		ret = clk_prepare_enable(priv->bus_clk);
		if (ret)
			return ret;
	}

	if (rk_priv) {
		ret = clk_bulk_prepare_enable(RK3568_MAX_CLKS,
					      rk_priv->rockchip_clks);
		if (ret)
			return ret;
	}

	return sdhci_resume_host(host);
}
#endif

static SIMPLE_DEV_PM_OPS(dwcmshc_pmops, dwcmshc_suspend, dwcmshc_resume);

static struct platform_driver sdhci_dwcmshc_driver = {
	.driver	= {
		.name	= "sdhci-dwcmshc",
		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
		.of_match_table = sdhci_dwcmshc_dt_ids,
		.pm = &dwcmshc_pmops,
	},
	.probe	= dwcmshc_probe,
	.remove	= dwcmshc_remove,
};
module_platform_driver(sdhci_dwcmshc_driver);

MODULE_DESCRIPTION("SDHCI platform driver for Synopsys DWC MSHC");
MODULE_AUTHOR("Jisheng Zhang <jszhang@kernel.org>");
MODULE_LICENSE("GPL v2");