mmc: sdhci-xenon: Add Marvell Xenon SDHC core functionality

Add Xenon eMMC/SD/SDIO host controller core functionality.
Add Xenon specific initialization process.
Add Xenon specific mmc_host_ops APIs.
Add Xenon specific register definitions.

Add CONFIG_MMC_SDHCI_XENON support in drivers/mmc/host/Kconfig.

Marvell Xenon SDHC conforms to SD Physical Layer Specification
Version 3.01 and is designed according to the guidelines provided
in the SD Host Controller Standard Specification Version 3.00.

Signed-off-by: Hu Ziji <huziji@marvell.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

1 files changed, 541 insertions, 0 deletions

diff --git a/drivers/mmc/host/sdhci-xenon.c b/drivers/mmc/host/sdhci-xenon.c
new file mode 100644
index 000000000000..b3f2b018fe3d
--- /dev/null
+++ b/drivers/mmc/host/sdhci-xenon.c
@@ -0,0 +1,541 @@
+/*
+ * Driver for Marvell Xenon SDHC as a platform device
+ *
+ * Copyright (C) 2016 Marvell, All Rights Reserved.
+ *
+ * Author:	Hu Ziji <huziji@marvell.com>
+ * Date:	2016-8-24
+ *
+ * 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 version 2.
+ *
+ * Inspired by Jisheng Zhang <jszhang@marvell.com>
+ * Special thanks to Video BG4 project team.
+ */
+
+#include <linux/delay.h>
+#include <linux/ktime.h>
+#include <linux/module.h>
+#include <linux/of.h>
+
+#include "sdhci-pltfm.h"
+#include "sdhci-xenon.h"
+
+static int xenon_enable_internal_clk(struct sdhci_host *host)
+{
+	u32 reg;
+	ktime_t timeout;
+
+	reg = sdhci_readl(host, SDHCI_CLOCK_CONTROL);
+	reg |= SDHCI_CLOCK_INT_EN;
+	sdhci_writel(host, reg, SDHCI_CLOCK_CONTROL);
+	/* Wait max 20 ms */
+	timeout = ktime_add_ms(ktime_get(), 20);
+	while (!((reg = sdhci_readw(host, SDHCI_CLOCK_CONTROL))
+			& SDHCI_CLOCK_INT_STABLE)) {
+		if (ktime_after(ktime_get(), timeout)) {
+			dev_err(mmc_dev(host->mmc), "Internal clock never stabilised.\n");
+			return -ETIMEDOUT;
+		}
+		usleep_range(900, 1100);
+	}
+
+	return 0;
+}
+
+/* Set SDCLK-off-while-idle */
+static void xenon_set_sdclk_off_idle(struct sdhci_host *host,
+				     unsigned char sdhc_id, bool enable)
+{
+	u32 reg;
+	u32 mask;
+
+	reg = sdhci_readl(host, XENON_SYS_OP_CTRL);
+	/* Get the bit shift basing on the SDHC index */
+	mask = (0x1 << (XENON_SDCLK_IDLEOFF_ENABLE_SHIFT + sdhc_id));
+	if (enable)
+		reg |= mask;
+	else
+		reg &= ~mask;
+
+	sdhci_writel(host, reg, XENON_SYS_OP_CTRL);
+}
+
+/* Enable/Disable the Auto Clock Gating function */
+static void xenon_set_acg(struct sdhci_host *host, bool enable)
+{
+	u32 reg;
+
+	reg = sdhci_readl(host, XENON_SYS_OP_CTRL);
+	if (enable)
+		reg &= ~XENON_AUTO_CLKGATE_DISABLE_MASK;
+	else
+		reg |= XENON_AUTO_CLKGATE_DISABLE_MASK;
+	sdhci_writel(host, reg, XENON_SYS_OP_CTRL);
+}
+
+/* Enable this SDHC */
+static void xenon_enable_sdhc(struct sdhci_host *host,
+			      unsigned char sdhc_id)
+{
+	u32 reg;
+
+	reg = sdhci_readl(host, XENON_SYS_OP_CTRL);
+	reg |= (BIT(sdhc_id) << XENON_SLOT_ENABLE_SHIFT);
+	sdhci_writel(host, reg, XENON_SYS_OP_CTRL);
+
+	host->mmc->caps |= MMC_CAP_WAIT_WHILE_BUSY;
+	/*
+	 * Force to clear BUS_TEST to
+	 * skip bus_test_pre and bus_test_post
+	 */
+	host->mmc->caps &= ~MMC_CAP_BUS_WIDTH_TEST;
+}
+
+/* Disable this SDHC */
+static void xenon_disable_sdhc(struct sdhci_host *host,
+			       unsigned char sdhc_id)
+{
+	u32 reg;
+
+	reg = sdhci_readl(host, XENON_SYS_OP_CTRL);
+	reg &= ~(BIT(sdhc_id) << XENON_SLOT_ENABLE_SHIFT);
+	sdhci_writel(host, reg, XENON_SYS_OP_CTRL);
+}
+
+/* Enable Parallel Transfer Mode */
+static void xenon_enable_sdhc_parallel_tran(struct sdhci_host *host,
+					    unsigned char sdhc_id)
+{
+	u32 reg;
+
+	reg = sdhci_readl(host, XENON_SYS_EXT_OP_CTRL);
+	reg |= BIT(sdhc_id);
+	sdhci_writel(host, reg, XENON_SYS_EXT_OP_CTRL);
+}
+
+/* Mask command conflict error */
+static void xenon_mask_cmd_conflict_err(struct sdhci_host *host)
+{
+	u32  reg;
+
+	reg = sdhci_readl(host, XENON_SYS_EXT_OP_CTRL);
+	reg |= XENON_MASK_CMD_CONFLICT_ERR;
+	sdhci_writel(host, reg, XENON_SYS_EXT_OP_CTRL);
+}
+
+static void xenon_retune_setup(struct sdhci_host *host)
+{
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	struct xenon_priv *priv = sdhci_pltfm_priv(pltfm_host);
+	u32 reg;
+
+	/* Disable the Re-Tuning Request functionality */
+	reg = sdhci_readl(host, XENON_SLOT_RETUNING_REQ_CTRL);
+	reg &= ~XENON_RETUNING_COMPATIBLE;
+	sdhci_writel(host, reg, XENON_SLOT_RETUNING_REQ_CTRL);
+
+	/* Disable the Re-tuning Interrupt */
+	reg = sdhci_readl(host, SDHCI_SIGNAL_ENABLE);
+	reg &= ~SDHCI_INT_RETUNE;
+	sdhci_writel(host, reg, SDHCI_SIGNAL_ENABLE);
+	reg = sdhci_readl(host, SDHCI_INT_ENABLE);
+	reg &= ~SDHCI_INT_RETUNE;
+	sdhci_writel(host, reg, SDHCI_INT_ENABLE);
+
+	/* Force to use Tuning Mode 1 */
+	host->tuning_mode = SDHCI_TUNING_MODE_1;
+	/* Set re-tuning period */
+	host->tuning_count = 1 << (priv->tuning_count - 1);
+}
+
+/*
+ * Operations inside struct sdhci_ops
+ */
+/* Recover the Register Setting cleared during SOFTWARE_RESET_ALL */
+static void xenon_reset_exit(struct sdhci_host *host,
+			     unsigned char sdhc_id, u8 mask)
+{
+	/* Only SOFTWARE RESET ALL will clear the register setting */
+	if (!(mask & SDHCI_RESET_ALL))
+		return;
+
+	/* Disable tuning request and auto-retuning again */
+	xenon_retune_setup(host);
+
+	xenon_set_acg(host, true);
+
+	xenon_set_sdclk_off_idle(host, sdhc_id, false);
+
+	xenon_mask_cmd_conflict_err(host);
+}
+
+static void xenon_reset(struct sdhci_host *host, u8 mask)
+{
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	struct xenon_priv *priv = sdhci_pltfm_priv(pltfm_host);
+
+	sdhci_reset(host, mask);
+	xenon_reset_exit(host, priv->sdhc_id, mask);
+}
+
+/*
+ * Xenon defines different values for HS200 and HS400
+ * in Host_Control_2
+ */
+static void xenon_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)
+		ctrl_2 |= XENON_CTRL_HS200;
+	else if (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)
+		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 |= XENON_CTRL_HS400;
+	sdhci_writew(host, ctrl_2, SDHCI_HOST_CONTROL2);
+}
+
+static const struct sdhci_ops sdhci_xenon_ops = {
+	.set_clock		= sdhci_set_clock,
+	.set_bus_width		= sdhci_set_bus_width,
+	.reset			= xenon_reset,
+	.set_uhs_signaling	= xenon_set_uhs_signaling,
+	.get_max_clock		= sdhci_pltfm_clk_get_max_clock,
+};
+
+static const struct sdhci_pltfm_data sdhci_xenon_pdata = {
+	.ops = &sdhci_xenon_ops,
+	.quirks = SDHCI_QUIRK_NO_ENDATTR_IN_NOPDESC |
+		  SDHCI_QUIRK_NO_SIMULT_VDD_AND_POWER |
+		  SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN,
+};
+
+/*
+ * Xenon Specific Operations in mmc_host_ops
+ */
+static void xenon_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
+{
+	struct sdhci_host *host = mmc_priv(mmc);
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	struct xenon_priv *priv = sdhci_pltfm_priv(pltfm_host);
+	u32 reg;
+
+	/*
+	 * HS400/HS200/eMMC HS doesn't have Preset Value register.
+	 * However, sdhci_set_ios will read HS400/HS200 Preset register.
+	 * Disable Preset Value register for HS400/HS200.
+	 * eMMC HS with preset_enabled set will trigger a bug in
+	 * get_preset_value().
+	 */
+	if ((ios->timing == MMC_TIMING_MMC_HS400) ||
+	    (ios->timing == MMC_TIMING_MMC_HS200) ||
+	    (ios->timing == MMC_TIMING_MMC_HS)) {
+		host->preset_enabled = false;
+		host->quirks2 |= SDHCI_QUIRK2_PRESET_VALUE_BROKEN;
+		host->flags &= ~SDHCI_PV_ENABLED;
+
+		reg = sdhci_readw(host, SDHCI_HOST_CONTROL2);
+		reg &= ~SDHCI_CTRL_PRESET_VAL_ENABLE;
+		sdhci_writew(host, reg, SDHCI_HOST_CONTROL2);
+	} else {
+		host->quirks2 &= ~SDHCI_QUIRK2_PRESET_VALUE_BROKEN;
+	}
+
+	sdhci_set_ios(mmc, ios);
+
+	if (host->clock > XENON_DEFAULT_SDCLK_FREQ)
+		xenon_set_sdclk_off_idle(host, priv->sdhc_id, true);
+}
+
+static int xenon_start_signal_voltage_switch(struct mmc_host *mmc,
+					     struct mmc_ios *ios)
+{
+	struct sdhci_host *host = mmc_priv(mmc);
+
+	/*
+	 * Before SD/SDIO set signal voltage, SD bus clock should be
+	 * disabled. However, sdhci_set_clock will also disable the Internal
+	 * clock in mmc_set_signal_voltage().
+	 * If Internal clock is disabled, the 3.3V/1.8V bit can not be updated.
+	 * Thus here manually enable internal clock.
+	 *
+	 * After switch completes, it is unnecessary to disable internal clock,
+	 * since keeping internal clock active obeys SD spec.
+	 */
+	xenon_enable_internal_clk(host);
+
+	/*
+	 * If Vqmmc is fixed on platform, vqmmc regulator should be unavailable.
+	 * Thus SDHCI_CTRL_VDD_180 bit might not work then.
+	 * Skip the standard voltage switch to avoid any issue.
+	 */
+	if (PTR_ERR(mmc->supply.vqmmc) == -ENODEV)
+		return 0;
+
+	return sdhci_start_signal_voltage_switch(mmc, ios);
+}
+
+/*
+ * Update card type.
+ * priv->init_card_type will be used in PHY timing adjustment.
+ */
+static void xenon_init_card(struct mmc_host *mmc, struct mmc_card *card)
+{
+	struct sdhci_host *host = mmc_priv(mmc);
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	struct xenon_priv *priv = sdhci_pltfm_priv(pltfm_host);
+
+	/* Update card type*/
+	priv->init_card_type = card->type;
+}
+
+static int xenon_execute_tuning(struct mmc_host *mmc, u32 opcode)
+{
+	struct sdhci_host *host = mmc_priv(mmc);
+
+	if (host->timing == MMC_TIMING_UHS_DDR50)
+		return 0;
+
+	/*
+	 * Currently force Xenon driver back to support mode 1 only,
+	 * even though Xenon might claim to support mode 2 or mode 3.
+	 * It requires more time to test mode 2/mode 3 on more platforms.
+	 */
+	if (host->tuning_mode != SDHCI_TUNING_MODE_1)
+		xenon_retune_setup(host);
+
+	return sdhci_execute_tuning(mmc, opcode);
+}
+
+static void xenon_enable_sdio_irq(struct mmc_host *mmc, int enable)
+{
+	struct sdhci_host *host = mmc_priv(mmc);
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	struct xenon_priv *priv = sdhci_pltfm_priv(pltfm_host);
+	u32 reg;
+	u8 sdhc_id = priv->sdhc_id;
+
+	sdhci_enable_sdio_irq(mmc, enable);
+
+	if (enable) {
+		/*
+		 * Set SDIO Card Inserted indication
+		 * to enable detecting SDIO async irq.
+		 */
+		reg = sdhci_readl(host, XENON_SYS_CFG_INFO);
+		reg |= (1 << (sdhc_id + XENON_SLOT_TYPE_SDIO_SHIFT));
+		sdhci_writel(host, reg, XENON_SYS_CFG_INFO);
+	} else {
+		/* Clear SDIO Card Inserted indication */
+		reg = sdhci_readl(host, XENON_SYS_CFG_INFO);
+		reg &= ~(1 << (sdhc_id + XENON_SLOT_TYPE_SDIO_SHIFT));
+		sdhci_writel(host, reg, XENON_SYS_CFG_INFO);
+	}
+}
+
+static void xenon_replace_mmc_host_ops(struct sdhci_host *host)
+{
+	host->mmc_host_ops.set_ios = xenon_set_ios;
+	host->mmc_host_ops.start_signal_voltage_switch =
+			xenon_start_signal_voltage_switch;
+	host->mmc_host_ops.init_card = xenon_init_card;
+	host->mmc_host_ops.execute_tuning = xenon_execute_tuning;
+	host->mmc_host_ops.enable_sdio_irq = xenon_enable_sdio_irq;
+}
+
+/*
+ * Parse Xenon specific DT properties:
+ * sdhc-id: the index of current SDHC.
+ *	    Refer to XENON_SYS_CFG_INFO register
+ * tun-count: the interval between re-tuning
+ */
+static int xenon_probe_dt(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct sdhci_host *host = platform_get_drvdata(pdev);
+	struct mmc_host *mmc = host->mmc;
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	struct xenon_priv *priv = sdhci_pltfm_priv(pltfm_host);
+	u32 sdhc_id, nr_sdhc;
+	u32 tuning_count;
+
+	/* Disable HS200 on Armada AP806 */
+	if (of_device_is_compatible(np, "marvell,armada-ap806-sdhci"))
+		host->quirks2 |= SDHCI_QUIRK2_BROKEN_HS200;
+
+	sdhc_id = 0x0;
+	if (!of_property_read_u32(np, "marvell,xenon-sdhc-id", &sdhc_id)) {
+		nr_sdhc = sdhci_readl(host, XENON_SYS_CFG_INFO);
+		nr_sdhc &= XENON_NR_SUPPORTED_SLOT_MASK;
+		if (unlikely(sdhc_id > nr_sdhc)) {
+			dev_err(mmc_dev(mmc), "SDHC Index %d exceeds Number of SDHCs %d\n",
+				sdhc_id, nr_sdhc);
+			return -EINVAL;
+		}
+	}
+	priv->sdhc_id = sdhc_id;
+
+	tuning_count = XENON_DEF_TUNING_COUNT;
+	if (!of_property_read_u32(np, "marvell,xenon-tun-count",
+				  &tuning_count)) {
+		if (unlikely(tuning_count >= XENON_TMR_RETUN_NO_PRESENT)) {
+			dev_err(mmc_dev(mmc), "Wrong Re-tuning Count. Set default value %d\n",
+				XENON_DEF_TUNING_COUNT);
+			tuning_count = XENON_DEF_TUNING_COUNT;
+		}
+	}
+	priv->tuning_count = tuning_count;
+
+	return 0;
+}
+
+static int xenon_sdhc_prepare(struct sdhci_host *host)
+{
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	struct xenon_priv *priv = sdhci_pltfm_priv(pltfm_host);
+	u8 sdhc_id = priv->sdhc_id;
+
+	/* Enable SDHC */
+	xenon_enable_sdhc(host, sdhc_id);
+
+	/* Enable ACG */
+	xenon_set_acg(host, true);
+
+	/* Enable Parallel Transfer Mode */
+	xenon_enable_sdhc_parallel_tran(host, sdhc_id);
+
+	/* Disable SDCLK-Off-While-Idle before card init */
+	xenon_set_sdclk_off_idle(host, sdhc_id, false);
+
+	xenon_mask_cmd_conflict_err(host);
+
+	return 0;
+}
+
+static void xenon_sdhc_unprepare(struct sdhci_host *host)
+{
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	struct xenon_priv *priv = sdhci_pltfm_priv(pltfm_host);
+	u8 sdhc_id = priv->sdhc_id;
+
+	/* disable SDHC */
+	xenon_disable_sdhc(host, sdhc_id);
+}
+
+static int xenon_probe(struct platform_device *pdev)
+{
+	struct sdhci_pltfm_host *pltfm_host;
+	struct sdhci_host *host;
+	struct xenon_priv *priv;
+	int err;
+
+	host = sdhci_pltfm_init(pdev, &sdhci_xenon_pdata,
+				sizeof(struct xenon_priv));
+	if (IS_ERR(host))
+		return PTR_ERR(host);
+
+	pltfm_host = sdhci_priv(host);
+	priv = sdhci_pltfm_priv(pltfm_host);
+
+	/*
+	 * Link Xenon specific mmc_host_ops function,
+	 * to replace standard ones in sdhci_ops.
+	 */
+	xenon_replace_mmc_host_ops(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 setup input clk: %d\n", err);
+		goto free_pltfm;
+	}
+	err = clk_prepare_enable(pltfm_host->clk);
+	if (err)
+		goto free_pltfm;
+
+	err = mmc_of_parse(host->mmc);
+	if (err)
+		goto err_clk;
+
+	sdhci_get_of_property(pdev);
+
+	xenon_set_acg(host, false);
+
+	/* Xenon specific dt parse */
+	err = xenon_probe_dt(pdev);
+	if (err)
+		goto err_clk;
+
+	err = xenon_sdhc_prepare(host);
+	if (err)
+		goto err_clk;
+
+	err = sdhci_add_host(host);
+	if (err)
+		goto remove_sdhc;
+
+	return 0;
+
+remove_sdhc:
+	xenon_sdhc_unprepare(host);
+err_clk:
+	clk_disable_unprepare(pltfm_host->clk);
+free_pltfm:
+	sdhci_pltfm_free(pdev);
+	return err;
+}
+
+static int xenon_remove(struct platform_device *pdev)
+{
+	struct sdhci_host *host = platform_get_drvdata(pdev);
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+
+	xenon_sdhc_unprepare(host);
+
+	sdhci_remove_host(host, 0);
+
+	clk_disable_unprepare(pltfm_host->clk);
+
+	sdhci_pltfm_free(pdev);
+
+	return 0;
+}
+
+static const struct of_device_id sdhci_xenon_dt_ids[] = {
+	{ .compatible = "marvell,armada-ap806-sdhci",},
+	{ .compatible = "marvell,armada-cp110-sdhci",},
+	{ .compatible = "marvell,armada-3700-sdhci",},
+	{}
+};
+MODULE_DEVICE_TABLE(of, sdhci_xenon_dt_ids);
+
+static struct platform_driver sdhci_xenon_driver = {
+	.driver	= {
+		.name	= "xenon-sdhci",
+		.of_match_table = sdhci_xenon_dt_ids,
+		.pm = &sdhci_pltfm_pmops,
+	},
+	.probe	= xenon_probe,
+	.remove	= xenon_remove,
+};
+
+module_platform_driver(sdhci_xenon_driver);
+
+MODULE_DESCRIPTION("SDHCI platform driver for Marvell Xenon SDHC");
+MODULE_AUTHOR("Hu Ziji <huziji@marvell.com>");
+MODULE_LICENSE("GPL v2");