mmc: sdhci-omap: Add OMAP SDHCI driver

Create a new sdhci-omap driver to configure the eMMC/SD/SDIO controller
in TI's OMAP SoCs making use of the SDHCI core library. For OMAP specific
configurations, populate sdhci_ops with OMAP specific callbacks and use
SDHCI quirks.
Enable only high speed mode for both SD and eMMC here and add other
UHS mode support later.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

1 files changed, 607 insertions, 0 deletions

diff --git a/drivers/mmc/host/sdhci-omap.c b/drivers/mmc/host/sdhci-omap.c
new file mode 100644
index 000000000000..5ddae39816b7
--- /dev/null
+++ b/drivers/mmc/host/sdhci-omap.c
@@ -0,0 +1,607 @@
+/**
+ * SDHCI Controller driver for TI's OMAP SoCs
+ *
+ * Copyright (C) 2017 Texas Instruments
+ * Author: Kishon Vijay Abraham I <kishon@ti.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 of
+ * the License as published by the Free Software Foundation.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/delay.h>
+#include <linux/mmc/slot-gpio.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/regulator/consumer.h>
+
+#include "sdhci-pltfm.h"
+
+#define SDHCI_OMAP_CON		0x12c
+#define CON_DW8			BIT(5)
+#define CON_DMA_MASTER		BIT(20)
+#define CON_INIT		BIT(1)
+#define CON_OD			BIT(0)
+
+#define SDHCI_OMAP_CMD		0x20c
+
+#define SDHCI_OMAP_HCTL		0x228
+#define HCTL_SDBP		BIT(8)
+#define HCTL_SDVS_SHIFT		9
+#define HCTL_SDVS_MASK		(0x7 << HCTL_SDVS_SHIFT)
+#define HCTL_SDVS_33		(0x7 << HCTL_SDVS_SHIFT)
+#define HCTL_SDVS_30		(0x6 << HCTL_SDVS_SHIFT)
+#define HCTL_SDVS_18		(0x5 << HCTL_SDVS_SHIFT)
+
+#define SDHCI_OMAP_SYSCTL	0x22c
+#define SYSCTL_CEN		BIT(2)
+#define SYSCTL_CLKD_SHIFT	6
+#define SYSCTL_CLKD_MASK	0x3ff
+
+#define SDHCI_OMAP_STAT		0x230
+
+#define SDHCI_OMAP_IE		0x234
+#define INT_CC_EN		BIT(0)
+
+#define SDHCI_OMAP_AC12		0x23c
+#define AC12_V1V8_SIGEN		BIT(19)
+
+#define SDHCI_OMAP_CAPA		0x240
+#define CAPA_VS33		BIT(24)
+#define CAPA_VS30		BIT(25)
+#define CAPA_VS18		BIT(26)
+
+#define SDHCI_OMAP_TIMEOUT	1		/* 1 msec */
+
+#define SYSCTL_CLKD_MAX		0x3FF
+
+#define IOV_1V8			1800000		/* 180000 uV */
+#define IOV_3V0			3000000		/* 300000 uV */
+#define IOV_3V3			3300000		/* 330000 uV */
+
+struct sdhci_omap_data {
+	u32 offset;
+};
+
+struct sdhci_omap_host {
+	void __iomem		*base;
+	struct device		*dev;
+	struct	regulator	*pbias;
+	bool			pbias_enabled;
+	struct sdhci_host	*host;
+	u8			bus_mode;
+	u8			power_mode;
+};
+
+static inline u32 sdhci_omap_readl(struct sdhci_omap_host *host,
+				   unsigned int offset)
+{
+	return readl(host->base + offset);
+}
+
+static inline void sdhci_omap_writel(struct sdhci_omap_host *host,
+				     unsigned int offset, u32 data)
+{
+	writel(data, host->base + offset);
+}
+
+static int sdhci_omap_set_pbias(struct sdhci_omap_host *omap_host,
+				bool power_on, unsigned int iov)
+{
+	int ret;
+	struct device *dev = omap_host->dev;
+
+	if (IS_ERR(omap_host->pbias))
+		return 0;
+
+	if (power_on) {
+		ret = regulator_set_voltage(omap_host->pbias, iov, iov);
+		if (ret) {
+			dev_err(dev, "pbias set voltage failed\n");
+			return ret;
+		}
+
+		if (omap_host->pbias_enabled)
+			return 0;
+
+		ret = regulator_enable(omap_host->pbias);
+		if (ret) {
+			dev_err(dev, "pbias reg enable fail\n");
+			return ret;
+		}
+
+		omap_host->pbias_enabled = true;
+	} else {
+		if (!omap_host->pbias_enabled)
+			return 0;
+
+		ret = regulator_disable(omap_host->pbias);
+		if (ret) {
+			dev_err(dev, "pbias reg disable fail\n");
+			return ret;
+		}
+		omap_host->pbias_enabled = false;
+	}
+
+	return 0;
+}
+
+static int sdhci_omap_enable_iov(struct sdhci_omap_host *omap_host,
+				 unsigned int iov)
+{
+	int ret;
+	struct sdhci_host *host = omap_host->host;
+	struct mmc_host *mmc = host->mmc;
+
+	ret = sdhci_omap_set_pbias(omap_host, false, 0);
+	if (ret)
+		return ret;
+
+	if (!IS_ERR(mmc->supply.vqmmc)) {
+		ret = regulator_set_voltage(mmc->supply.vqmmc, iov, iov);
+		if (ret) {
+			dev_err(mmc_dev(mmc), "vqmmc set voltage failed\n");
+			return ret;
+		}
+	}
+
+	ret = sdhci_omap_set_pbias(omap_host, true, iov);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static void sdhci_omap_conf_bus_power(struct sdhci_omap_host *omap_host,
+				      unsigned char signal_voltage)
+{
+	u32 reg;
+	ktime_t timeout;
+
+	reg = sdhci_omap_readl(omap_host, SDHCI_OMAP_HCTL);
+	reg &= ~HCTL_SDVS_MASK;
+
+	if (signal_voltage == MMC_SIGNAL_VOLTAGE_330)
+		reg |= HCTL_SDVS_33;
+	else
+		reg |= HCTL_SDVS_18;
+
+	sdhci_omap_writel(omap_host, SDHCI_OMAP_HCTL, reg);
+
+	reg |= HCTL_SDBP;
+	sdhci_omap_writel(omap_host, SDHCI_OMAP_HCTL, reg);
+
+	/* wait 1ms */
+	timeout = ktime_add_ms(ktime_get(), SDHCI_OMAP_TIMEOUT);
+	while (!(sdhci_omap_readl(omap_host, SDHCI_OMAP_HCTL) & HCTL_SDBP)) {
+		if (WARN_ON(ktime_after(ktime_get(), timeout)))
+			return;
+		usleep_range(5, 10);
+	}
+}
+
+static int sdhci_omap_start_signal_voltage_switch(struct mmc_host *mmc,
+						  struct mmc_ios *ios)
+{
+	u32 reg;
+	int ret;
+	unsigned int iov;
+	struct sdhci_host *host = mmc_priv(mmc);
+	struct sdhci_pltfm_host *pltfm_host;
+	struct sdhci_omap_host *omap_host;
+	struct device *dev;
+
+	pltfm_host = sdhci_priv(host);
+	omap_host = sdhci_pltfm_priv(pltfm_host);
+	dev = omap_host->dev;
+
+	if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_330) {
+		reg = sdhci_omap_readl(omap_host, SDHCI_OMAP_CAPA);
+		if (!(reg & CAPA_VS33))
+			return -EOPNOTSUPP;
+
+		sdhci_omap_conf_bus_power(omap_host, ios->signal_voltage);
+
+		reg = sdhci_omap_readl(omap_host, SDHCI_OMAP_AC12);
+		reg &= ~AC12_V1V8_SIGEN;
+		sdhci_omap_writel(omap_host, SDHCI_OMAP_AC12, reg);
+
+		iov = IOV_3V3;
+	} else if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_180) {
+		reg = sdhci_omap_readl(omap_host, SDHCI_OMAP_CAPA);
+		if (!(reg & CAPA_VS18))
+			return -EOPNOTSUPP;
+
+		sdhci_omap_conf_bus_power(omap_host, ios->signal_voltage);
+
+		reg = sdhci_omap_readl(omap_host, SDHCI_OMAP_AC12);
+		reg |= AC12_V1V8_SIGEN;
+		sdhci_omap_writel(omap_host, SDHCI_OMAP_AC12, reg);
+
+		iov = IOV_1V8;
+	} else {
+		return -EOPNOTSUPP;
+	}
+
+	ret = sdhci_omap_enable_iov(omap_host, iov);
+	if (ret) {
+		dev_err(dev, "failed to switch IO voltage to %dmV\n", iov);
+		return ret;
+	}
+
+	dev_dbg(dev, "IO voltage switched to %dmV\n", iov);
+	return 0;
+}
+
+static void sdhci_omap_set_bus_mode(struct sdhci_omap_host *omap_host,
+				    unsigned int mode)
+{
+	u32 reg;
+
+	if (omap_host->bus_mode == mode)
+		return;
+
+	reg = sdhci_omap_readl(omap_host, SDHCI_OMAP_CON);
+	if (mode == MMC_BUSMODE_OPENDRAIN)
+		reg |= CON_OD;
+	else
+		reg &= ~CON_OD;
+	sdhci_omap_writel(omap_host, SDHCI_OMAP_CON, reg);
+
+	omap_host->bus_mode = mode;
+}
+
+void sdhci_omap_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
+{
+	struct sdhci_host *host = mmc_priv(mmc);
+	struct sdhci_pltfm_host *pltfm_host;
+	struct sdhci_omap_host *omap_host;
+
+	pltfm_host = sdhci_priv(host);
+	omap_host = sdhci_pltfm_priv(pltfm_host);
+
+	sdhci_omap_set_bus_mode(omap_host, ios->bus_mode);
+	sdhci_set_ios(mmc, ios);
+}
+
+static u16 sdhci_omap_calc_divisor(struct sdhci_pltfm_host *host,
+				   unsigned int clock)
+{
+	u16 dsor;
+
+	dsor = DIV_ROUND_UP(clk_get_rate(host->clk), clock);
+	if (dsor > SYSCTL_CLKD_MAX)
+		dsor = SYSCTL_CLKD_MAX;
+
+	return dsor;
+}
+
+static void sdhci_omap_start_clock(struct sdhci_omap_host *omap_host)
+{
+	u32 reg;
+
+	reg = sdhci_omap_readl(omap_host, SDHCI_OMAP_SYSCTL);
+	reg |= SYSCTL_CEN;
+	sdhci_omap_writel(omap_host, SDHCI_OMAP_SYSCTL, reg);
+}
+
+static void sdhci_omap_stop_clock(struct sdhci_omap_host *omap_host)
+{
+	u32 reg;
+
+	reg = sdhci_omap_readl(omap_host, SDHCI_OMAP_SYSCTL);
+	reg &= ~SYSCTL_CEN;
+	sdhci_omap_writel(omap_host, SDHCI_OMAP_SYSCTL, reg);
+}
+
+static void sdhci_omap_set_clock(struct sdhci_host *host, unsigned int clock)
+{
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	struct sdhci_omap_host *omap_host = sdhci_pltfm_priv(pltfm_host);
+	unsigned long clkdiv;
+
+	sdhci_omap_stop_clock(omap_host);
+
+	if (!clock)
+		return;
+
+	clkdiv = sdhci_omap_calc_divisor(pltfm_host, clock);
+	clkdiv = (clkdiv & SYSCTL_CLKD_MASK) << SYSCTL_CLKD_SHIFT;
+	sdhci_enable_clk(host, clkdiv);
+
+	sdhci_omap_start_clock(omap_host);
+}
+
+void sdhci_omap_set_power(struct sdhci_host *host, unsigned char mode,
+			  unsigned short vdd)
+{
+	struct mmc_host *mmc = host->mmc;
+
+	mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, vdd);
+}
+
+static int sdhci_omap_enable_dma(struct sdhci_host *host)
+{
+	u32 reg;
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	struct sdhci_omap_host *omap_host = sdhci_pltfm_priv(pltfm_host);
+
+	reg = sdhci_omap_readl(omap_host, SDHCI_OMAP_CON);
+	reg |= CON_DMA_MASTER;
+	sdhci_omap_writel(omap_host, SDHCI_OMAP_CON, reg);
+
+	return 0;
+}
+
+unsigned int sdhci_omap_get_min_clock(struct sdhci_host *host)
+{
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+
+	return clk_get_rate(pltfm_host->clk) / SYSCTL_CLKD_MAX;
+}
+
+static void sdhci_omap_set_bus_width(struct sdhci_host *host, int width)
+{
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	struct sdhci_omap_host *omap_host = sdhci_pltfm_priv(pltfm_host);
+	u32 reg;
+
+	reg = sdhci_omap_readl(omap_host, SDHCI_OMAP_CON);
+	if (width == MMC_BUS_WIDTH_8)
+		reg |= CON_DW8;
+	else
+		reg &= ~CON_DW8;
+	sdhci_omap_writel(omap_host, SDHCI_OMAP_CON, reg);
+
+	sdhci_set_bus_width(host, width);
+}
+
+static void sdhci_omap_init_74_clocks(struct sdhci_host *host, u8 power_mode)
+{
+	u32 reg;
+	ktime_t timeout;
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	struct sdhci_omap_host *omap_host = sdhci_pltfm_priv(pltfm_host);
+
+	if (omap_host->power_mode == power_mode)
+		return;
+
+	if (power_mode != MMC_POWER_ON)
+		return;
+
+	disable_irq(host->irq);
+
+	reg = sdhci_omap_readl(omap_host, SDHCI_OMAP_CON);
+	reg |= CON_INIT;
+	sdhci_omap_writel(omap_host, SDHCI_OMAP_CON, reg);
+	sdhci_omap_writel(omap_host, SDHCI_OMAP_CMD, 0x0);
+
+	/* wait 1ms */
+	timeout = ktime_add_ms(ktime_get(), SDHCI_OMAP_TIMEOUT);
+	while (!(sdhci_omap_readl(omap_host, SDHCI_OMAP_STAT) & INT_CC_EN)) {
+		if (WARN_ON(ktime_after(ktime_get(), timeout)))
+			return;
+		usleep_range(5, 10);
+	}
+
+	reg = sdhci_omap_readl(omap_host, SDHCI_OMAP_CON);
+	reg &= ~CON_INIT;
+	sdhci_omap_writel(omap_host, SDHCI_OMAP_CON, reg);
+	sdhci_omap_writel(omap_host, SDHCI_OMAP_STAT, INT_CC_EN);
+
+	enable_irq(host->irq);
+
+	omap_host->power_mode = power_mode;
+}
+
+static struct sdhci_ops sdhci_omap_ops = {
+	.set_clock = sdhci_omap_set_clock,
+	.set_power = sdhci_omap_set_power,
+	.enable_dma = sdhci_omap_enable_dma,
+	.get_max_clock = sdhci_pltfm_clk_get_max_clock,
+	.get_min_clock = sdhci_omap_get_min_clock,
+	.set_bus_width = sdhci_omap_set_bus_width,
+	.platform_send_init_74_clocks = sdhci_omap_init_74_clocks,
+	.reset = sdhci_reset,
+	.set_uhs_signaling = sdhci_set_uhs_signaling,
+};
+
+static int sdhci_omap_set_capabilities(struct sdhci_omap_host *omap_host)
+{
+	u32 reg;
+	int ret = 0;
+	struct device *dev = omap_host->dev;
+	struct regulator *vqmmc;
+
+	vqmmc = regulator_get(dev, "vqmmc");
+	if (IS_ERR(vqmmc)) {
+		ret = PTR_ERR(vqmmc);
+		goto reg_put;
+	}
+
+	/* voltage capabilities might be set by boot loader, clear it */
+	reg = sdhci_omap_readl(omap_host, SDHCI_OMAP_CAPA);
+	reg &= ~(CAPA_VS18 | CAPA_VS30 | CAPA_VS33);
+
+	if (regulator_is_supported_voltage(vqmmc, IOV_3V3, IOV_3V3))
+		reg |= CAPA_VS33;
+	if (regulator_is_supported_voltage(vqmmc, IOV_1V8, IOV_1V8))
+		reg |= CAPA_VS18;
+
+	sdhci_omap_writel(omap_host, SDHCI_OMAP_CAPA, reg);
+
+reg_put:
+	regulator_put(vqmmc);
+
+	return ret;
+}
+
+static const struct sdhci_pltfm_data sdhci_omap_pdata = {
+	.quirks = SDHCI_QUIRK_BROKEN_CARD_DETECTION |
+		  SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK |
+		  SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN |
+		  SDHCI_QUIRK_NO_HISPD_BIT |
+		  SDHCI_QUIRK_BROKEN_ADMA_ZEROLEN_DESC,
+	.quirks2 = SDHCI_QUIRK2_NO_1_8_V |
+		   SDHCI_QUIRK2_ACMD23_BROKEN |
+		   SDHCI_QUIRK2_RSP_136_HAS_CRC,
+	.ops = &sdhci_omap_ops,
+};
+
+static const struct sdhci_omap_data dra7_data = {
+	.offset = 0x200,
+};
+
+static const struct of_device_id omap_sdhci_match[] = {
+	{ .compatible = "ti,dra7-sdhci", .data = &dra7_data },
+	{},
+};
+MODULE_DEVICE_TABLE(of, omap_sdhci_match);
+
+static int sdhci_omap_probe(struct platform_device *pdev)
+{
+	int ret;
+	u32 offset;
+	struct device *dev = &pdev->dev;
+	struct sdhci_host *host;
+	struct sdhci_pltfm_host *pltfm_host;
+	struct sdhci_omap_host *omap_host;
+	struct mmc_host *mmc;
+	const struct of_device_id *match;
+	struct sdhci_omap_data *data;
+
+	match = of_match_device(omap_sdhci_match, dev);
+	if (!match)
+		return -EINVAL;
+
+	data = (struct sdhci_omap_data *)match->data;
+	if (!data) {
+		dev_err(dev, "no sdhci omap data\n");
+		return -EINVAL;
+	}
+	offset = data->offset;
+
+	host = sdhci_pltfm_init(pdev, &sdhci_omap_pdata,
+				sizeof(*omap_host));
+	if (IS_ERR(host)) {
+		dev_err(dev, "Failed sdhci_pltfm_init\n");
+		return PTR_ERR(host);
+	}
+
+	pltfm_host = sdhci_priv(host);
+	omap_host = sdhci_pltfm_priv(pltfm_host);
+	omap_host->host = host;
+	omap_host->base = host->ioaddr;
+	omap_host->dev = dev;
+	host->ioaddr += offset;
+
+	mmc = host->mmc;
+	ret = mmc_of_parse(mmc);
+	if (ret)
+		goto err_pltfm_free;
+
+	pltfm_host->clk = devm_clk_get(dev, "fck");
+	if (IS_ERR(pltfm_host->clk)) {
+		ret = PTR_ERR(pltfm_host->clk);
+		goto err_pltfm_free;
+	}
+
+	ret = clk_set_rate(pltfm_host->clk, mmc->f_max);
+	if (ret) {
+		dev_err(dev, "failed to set clock to %d\n", mmc->f_max);
+		goto err_pltfm_free;
+	}
+
+	omap_host->pbias = devm_regulator_get_optional(dev, "pbias");
+	if (IS_ERR(omap_host->pbias)) {
+		ret = PTR_ERR(omap_host->pbias);
+		if (ret != -ENODEV)
+			goto err_pltfm_free;
+		dev_dbg(dev, "unable to get pbias regulator %d\n", ret);
+	}
+	omap_host->pbias_enabled = false;
+
+	/*
+	 * omap_device_pm_domain has callbacks to enable the main
+	 * functional clock, interface clock and also configure the
+	 * SYSCONFIG register of omap devices. The callback will be invoked
+	 * as part of pm_runtime_get_sync.
+	 */
+	pm_runtime_enable(dev);
+	ret = pm_runtime_get_sync(dev);
+	if (ret < 0) {
+		dev_err(dev, "pm_runtime_get_sync failed\n");
+		pm_runtime_put_noidle(dev);
+		goto err_rpm_disable;
+	}
+
+	ret = sdhci_omap_set_capabilities(omap_host);
+	if (ret) {
+		dev_err(dev, "failed to set system capabilities\n");
+		goto err_put_sync;
+	}
+
+	host->mmc_host_ops.get_ro = mmc_gpio_get_ro;
+	host->mmc_host_ops.start_signal_voltage_switch =
+					sdhci_omap_start_signal_voltage_switch;
+	host->mmc_host_ops.set_ios = sdhci_omap_set_ios;
+
+	sdhci_read_caps(host);
+	host->caps |= SDHCI_CAN_DO_ADMA2;
+
+	ret = sdhci_add_host(host);
+	if (ret)
+		goto err_put_sync;
+
+	return 0;
+
+err_put_sync:
+	pm_runtime_put_sync(dev);
+
+err_rpm_disable:
+	pm_runtime_disable(dev);
+
+err_pltfm_free:
+	sdhci_pltfm_free(pdev);
+	return ret;
+}
+
+static int sdhci_omap_remove(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct sdhci_host *host = platform_get_drvdata(pdev);
+
+	sdhci_remove_host(host, true);
+	pm_runtime_put_sync(dev);
+	pm_runtime_disable(dev);
+	sdhci_pltfm_free(pdev);
+
+	return 0;
+}
+
+static struct platform_driver sdhci_omap_driver = {
+	.probe = sdhci_omap_probe,
+	.remove = sdhci_omap_remove,
+	.driver = {
+		   .name = "sdhci-omap",
+		   .of_match_table = omap_sdhci_match,
+		  },
+};
+
+module_platform_driver(sdhci_omap_driver);
+
+MODULE_DESCRIPTION("SDHCI driver for OMAP SoCs");
+MODULE_AUTHOR("Texas Instruments Inc.");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:sdhci_omap");