xref: /openbmc/linux/drivers/mmc/host/sdhci-brcmstb.c (revision 6bcc55fe)

// SPDX-License-Identifier: GPL-2.0-only
/*
 * sdhci-brcmstb.c Support for SDHCI on Broadcom BRCMSTB SoC's
 *
 * Copyright (C) 2015 Broadcom Corporation
 */

#include <linux/io.h>
#include <linux/mmc/host.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/bitops.h>
#include <linux/delay.h>

#include "sdhci-pltfm.h"
#include "cqhci.h"

#define SDHCI_VENDOR 0x78
#define  SDHCI_VENDOR_ENHANCED_STRB 0x1
#define  SDHCI_VENDOR_GATE_SDCLK_EN 0x2

#define BRCMSTB_MATCH_FLAGS_NO_64BIT		BIT(0)
#define BRCMSTB_MATCH_FLAGS_BROKEN_TIMEOUT	BIT(1)
#define BRCMSTB_MATCH_FLAGS_HAS_CLOCK_GATE	BIT(2)

#define BRCMSTB_PRIV_FLAGS_HAS_CQE		BIT(0)
#define BRCMSTB_PRIV_FLAGS_GATE_CLOCK		BIT(1)

#define SDHCI_ARASAN_CQE_BASE_ADDR		0x200

struct sdhci_brcmstb_priv {
	void __iomem *cfg_regs;
	unsigned int flags;
};

struct brcmstb_match_priv {
	void (*hs400es)(struct mmc_host *mmc, struct mmc_ios *ios);
	struct sdhci_ops *ops;
	const unsigned int flags;
};

static inline void enable_clock_gating(struct sdhci_host *host)
{
	u32 reg;

	reg = sdhci_readl(host, SDHCI_VENDOR);
	reg |= SDHCI_VENDOR_GATE_SDCLK_EN;
	sdhci_writel(host, reg, SDHCI_VENDOR);
}

void brcmstb_reset(struct sdhci_host *host, u8 mask)
{
	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
	struct sdhci_brcmstb_priv *priv = sdhci_pltfm_priv(pltfm_host);

	sdhci_reset(host, mask);

	/* Reset will clear this, so re-enable it */
	if (priv->flags & BRCMSTB_PRIV_FLAGS_GATE_CLOCK)
		enable_clock_gating(host);
}

static void sdhci_brcmstb_hs400es(struct mmc_host *mmc, struct mmc_ios *ios)
{
	struct sdhci_host *host = mmc_priv(mmc);

	u32 reg;

	dev_dbg(mmc_dev(mmc), "%s(): Setting HS400-Enhanced-Strobe mode\n",
		__func__);
	reg = readl(host->ioaddr + SDHCI_VENDOR);
	if (ios->enhanced_strobe)
		reg |= SDHCI_VENDOR_ENHANCED_STRB;
	else
		reg &= ~SDHCI_VENDOR_ENHANCED_STRB;
	writel(reg, host->ioaddr + SDHCI_VENDOR);
}

static void sdhci_brcmstb_set_clock(struct sdhci_host *host, unsigned int clock)
{
	u16 clk;

	host->mmc->actual_clock = 0;

	clk = sdhci_calc_clk(host, clock, &host->mmc->actual_clock);
	sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);

	if (clock == 0)
		return;

	sdhci_enable_clk(host, clk);
}

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

	dev_dbg(mmc_dev(host->mmc), "%s: Setting UHS signaling for %d timing\n",
		__func__, timing);
	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_SD_HS ||
		 timing == MMC_TIMING_MMC_HS ||
		 timing == MMC_TIMING_UHS_SDR25)
		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 |= SDHCI_CTRL_HS400; /* Non-standard */
	sdhci_writew(host, ctrl_2, SDHCI_HOST_CONTROL2);
}

static void sdhci_brcmstb_dumpregs(struct mmc_host *mmc)
{
	sdhci_dumpregs(mmc_priv(mmc));
}

static void sdhci_brcmstb_cqe_enable(struct mmc_host *mmc)
{
	struct sdhci_host *host = mmc_priv(mmc);
	u32 reg;

	reg = sdhci_readl(host, SDHCI_PRESENT_STATE);
	while (reg & SDHCI_DATA_AVAILABLE) {
		sdhci_readl(host, SDHCI_BUFFER);
		reg = sdhci_readl(host, SDHCI_PRESENT_STATE);
	}

	sdhci_cqe_enable(mmc);
}

static const struct cqhci_host_ops sdhci_brcmstb_cqhci_ops = {
	.enable         = sdhci_brcmstb_cqe_enable,
	.disable        = sdhci_cqe_disable,
	.dumpregs       = sdhci_brcmstb_dumpregs,
};

static struct sdhci_ops sdhci_brcmstb_ops = {
	.set_clock = sdhci_set_clock,
	.set_bus_width = sdhci_set_bus_width,
	.reset = sdhci_reset,
	.set_uhs_signaling = sdhci_set_uhs_signaling,
};

static struct sdhci_ops sdhci_brcmstb_ops_7216 = {
	.set_clock = sdhci_brcmstb_set_clock,
	.set_bus_width = sdhci_set_bus_width,
	.reset = brcmstb_reset,
	.set_uhs_signaling = sdhci_brcmstb_set_uhs_signaling,
};

static struct brcmstb_match_priv match_priv_7425 = {
	.flags = BRCMSTB_MATCH_FLAGS_NO_64BIT |
	BRCMSTB_MATCH_FLAGS_BROKEN_TIMEOUT,
	.ops = &sdhci_brcmstb_ops,
};

static struct brcmstb_match_priv match_priv_7445 = {
	.flags = BRCMSTB_MATCH_FLAGS_BROKEN_TIMEOUT,
	.ops = &sdhci_brcmstb_ops,
};

static const struct brcmstb_match_priv match_priv_7216 = {
	.flags = BRCMSTB_MATCH_FLAGS_HAS_CLOCK_GATE,
	.hs400es = sdhci_brcmstb_hs400es,
	.ops = &sdhci_brcmstb_ops_7216,
};

static const struct of_device_id sdhci_brcm_of_match[] = {
	{ .compatible = "brcm,bcm7425-sdhci", .data = &match_priv_7425 },
	{ .compatible = "brcm,bcm7445-sdhci", .data = &match_priv_7445 },
	{ .compatible = "brcm,bcm7216-sdhci", .data = &match_priv_7216 },
	{},
};

static u32 sdhci_brcmstb_cqhci_irq(struct sdhci_host *host, u32 intmask)
{
	int cmd_error = 0;
	int data_error = 0;

	if (!sdhci_cqe_irq(host, intmask, &cmd_error, &data_error))
		return intmask;

	cqhci_irq(host->mmc, intmask, cmd_error, data_error);

	return 0;
}

static int sdhci_brcmstb_add_host(struct sdhci_host *host,
				  struct sdhci_brcmstb_priv *priv)
{
	struct cqhci_host *cq_host;
	bool dma64;
	int ret;

	if ((priv->flags & BRCMSTB_PRIV_FLAGS_HAS_CQE) == 0)
		return sdhci_add_host(host);

	dev_dbg(mmc_dev(host->mmc), "CQE is enabled\n");
	host->mmc->caps2 |= MMC_CAP2_CQE | MMC_CAP2_CQE_DCMD;
	ret = sdhci_setup_host(host);
	if (ret)
		return ret;

	cq_host = devm_kzalloc(mmc_dev(host->mmc),
			       sizeof(*cq_host), GFP_KERNEL);
	if (!cq_host) {
		ret = -ENOMEM;
		goto cleanup;
	}

	cq_host->mmio = host->ioaddr + SDHCI_ARASAN_CQE_BASE_ADDR;
	cq_host->ops = &sdhci_brcmstb_cqhci_ops;

	dma64 = host->flags & SDHCI_USE_64_BIT_DMA;
	if (dma64) {
		dev_dbg(mmc_dev(host->mmc), "Using 64 bit DMA\n");
		cq_host->caps |= CQHCI_TASK_DESC_SZ_128;
	}

	ret = cqhci_init(cq_host, host->mmc, dma64);
	if (ret)
		goto cleanup;

	ret = __sdhci_add_host(host);
	if (ret)
		goto cleanup;

	return 0;

cleanup:
	sdhci_cleanup_host(host);
	return ret;
}

static int sdhci_brcmstb_probe(struct platform_device *pdev)
{
	const struct brcmstb_match_priv *match_priv;
	struct sdhci_pltfm_data brcmstb_pdata;
	struct sdhci_pltfm_host *pltfm_host;
	const struct of_device_id *match;
	struct sdhci_brcmstb_priv *priv;
	struct sdhci_host *host;
	struct resource *iomem;
	struct clk *clk;
	int res;

	match = of_match_node(sdhci_brcm_of_match, pdev->dev.of_node);
	match_priv = match->data;

	dev_dbg(&pdev->dev, "Probe found match for %s\n",  match->compatible);

	clk = devm_clk_get_optional(&pdev->dev, NULL);
	if (IS_ERR(clk))
		return dev_err_probe(&pdev->dev, PTR_ERR(clk),
				     "Failed to get clock from Device Tree\n");

	res = clk_prepare_enable(clk);
	if (res)
		return res;

	memset(&brcmstb_pdata, 0, sizeof(brcmstb_pdata));
	brcmstb_pdata.ops = match_priv->ops;
	host = sdhci_pltfm_init(pdev, &brcmstb_pdata,
				sizeof(struct sdhci_brcmstb_priv));
	if (IS_ERR(host)) {
		res = PTR_ERR(host);
		goto err_clk;
	}

	pltfm_host = sdhci_priv(host);
	priv = sdhci_pltfm_priv(pltfm_host);
	if (device_property_read_bool(&pdev->dev, "supports-cqe")) {
		priv->flags |= BRCMSTB_PRIV_FLAGS_HAS_CQE;
		match_priv->ops->irq = sdhci_brcmstb_cqhci_irq;
	}

	/* Map in the non-standard CFG registers */
	iomem = platform_get_resource(pdev, IORESOURCE_MEM, 1);
	priv->cfg_regs = devm_ioremap_resource(&pdev->dev, iomem);
	if (IS_ERR(priv->cfg_regs)) {
		res = PTR_ERR(priv->cfg_regs);
		goto err;
	}

	sdhci_get_of_property(pdev);
	res = mmc_of_parse(host->mmc);
	if (res)
		goto err;

	/*
	 * Automatic clock gating does not work for SD cards that may
	 * voltage switch so only enable it for non-removable devices.
	 */
	if ((match_priv->flags & BRCMSTB_MATCH_FLAGS_HAS_CLOCK_GATE) &&
	    (host->mmc->caps & MMC_CAP_NONREMOVABLE))
		priv->flags |= BRCMSTB_PRIV_FLAGS_GATE_CLOCK;

	/*
	 * If the chip has enhanced strobe and it's enabled, add
	 * callback
	 */
	if (match_priv->hs400es &&
	    (host->mmc->caps2 & MMC_CAP2_HS400_ES))
		host->mmc_host_ops.hs400_enhanced_strobe = match_priv->hs400es;

	/*
	 * Supply the existing CAPS, but clear the UHS modes. This
	 * will allow these modes to be specified by device tree
	 * properties through mmc_of_parse().
	 */
	host->caps = sdhci_readl(host, SDHCI_CAPABILITIES);
	if (match_priv->flags & BRCMSTB_MATCH_FLAGS_NO_64BIT)
		host->caps &= ~SDHCI_CAN_64BIT;
	host->caps1 = sdhci_readl(host, SDHCI_CAPABILITIES_1);
	host->caps1 &= ~(SDHCI_SUPPORT_SDR50 | SDHCI_SUPPORT_SDR104 |
			 SDHCI_SUPPORT_DDR50);
	host->quirks |= SDHCI_QUIRK_MISSING_CAPS;

	if (match_priv->flags & BRCMSTB_MATCH_FLAGS_BROKEN_TIMEOUT)
		host->quirks |= SDHCI_QUIRK_BROKEN_TIMEOUT_VAL;

	res = sdhci_brcmstb_add_host(host, priv);
	if (res)
		goto err;

	pltfm_host->clk = clk;
	return res;

err:
	sdhci_pltfm_free(pdev);
err_clk:
	clk_disable_unprepare(clk);
	return res;
}

static void sdhci_brcmstb_shutdown(struct platform_device *pdev)
{
	sdhci_pltfm_suspend(&pdev->dev);
}

MODULE_DEVICE_TABLE(of, sdhci_brcm_of_match);

static struct platform_driver sdhci_brcmstb_driver = {
	.driver		= {
		.name	= "sdhci-brcmstb",
		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
		.pm	= &sdhci_pltfm_pmops,
		.of_match_table = of_match_ptr(sdhci_brcm_of_match),
	},
	.probe		= sdhci_brcmstb_probe,
	.remove		= sdhci_pltfm_unregister,
	.shutdown	= sdhci_brcmstb_shutdown,
};

module_platform_driver(sdhci_brcmstb_driver);

MODULE_DESCRIPTION("SDHCI driver for Broadcom BRCMSTB SoCs");
MODULE_AUTHOR("Broadcom");
MODULE_LICENSE("GPL v2");