mmc: sdhci-brcmstb: Add driver for Broadcom BRCMSTB SoCs

Add SDHCI driver for Broadcom BRCMSTB SoCs.
This driver works with all ARM based SoCs and the 7425, 7429
and 7435 MIPS based SoCs.

The driver disables all UHS speed modes by default and relies
on the Device Tree node properties to enable these modes for
SoC/Board combinations that support them.

Signed-off-by: Al Cooper <alcooperx@gmail.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

MAINTAINERS

@@ -10209,6 +10209,13 @@ F:	tools/testing/selftests/seccomp/*
 K:	\bsecure_computing
 K:	\bTIF_SECCOMP\b
 
+SECURE DIGITAL HOST CONTROLLER INTERFACE (SDHCI) Broadcom BRCMSTB DRIVER
+M:	Al Cooper <alcooperx@gmail.com>
+L:	linux-mmc@vger.kernel.org
+L:	bcm-kernel-feedback-list@broadcom.com
+S:	Maintained
+F:	drivers/mmc/host/sdhci-brcmstb*
+
 SECURE DIGITAL HOST CONTROLLER INTERFACE (SDHCI) SAMSUNG DRIVER
 M:	Ben Dooks <ben-linux@fluff.org>
 M:	Jaehoon Chung <jh80.chung@samsung.com>

drivers/mmc/host/Kconfig

@@ -787,3 +787,13 @@ config MMC_SDHCI_MICROCHIP_PIC32
           If you have a controller with this interface, say Y or M here.
 
           If unsure, say N.
+config MMC_SDHCI_BRCMSTB
+	tristate "Broadcom SDIO/SD/MMC support"
+	depends on ARCH_BRCMSTB || BMIPS_GENERIC
+	depends on MMC_SDHCI_PLTFM
+	default y
+	help
+	  This selects support for the SDIO/SD/MMC Host Controller on
+	  Broadcom STB SoCs.
+
+	  If unsure, say Y.

drivers/mmc/host/Makefile

@@ -75,6 +75,7 @@ obj-$(CONFIG_MMC_SDHCI_IPROC)		+= sdhci-iproc.o
 obj-$(CONFIG_MMC_SDHCI_MSM)		+= sdhci-msm.o
 obj-$(CONFIG_MMC_SDHCI_ST)		+= sdhci-st.o
 obj-$(CONFIG_MMC_SDHCI_MICROCHIP_PIC32)	+= sdhci-pic32.o
+obj-$(CONFIG_MMC_SDHCI_BRCMSTB)		+= sdhci-brcmstb.o
 
 ifeq ($(CONFIG_CB710_DEBUG),y)
 	CFLAGS-cb710-mmc	+= -DDEBUG

drivers/mmc/host/sdhci-brcmstb.c

@@ -0,0 +1,143 @@
+/*
+ * sdhci-brcmstb.c Support for SDHCI on Broadcom BRCMSTB SoC's
+ *
+ * Copyright (C) 2015 Broadcom Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 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.
+ *
+ */
+
+#include <linux/io.h>
+#include <linux/mmc/host.h>
+#include <linux/module.h>
+#include <linux/of.h>
+
+#include "sdhci-pltfm.h"
+
+#ifdef CONFIG_PM_SLEEP
+
+static int sdhci_brcmstb_suspend(struct device *dev)
+{
+	struct sdhci_host *host = dev_get_drvdata(dev);
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	int res;
+
+	res = sdhci_suspend_host(host);
+	if (res)
+		return res;
+	clk_disable_unprepare(pltfm_host->clk);
+	return res;
+}
+
+static int sdhci_brcmstb_resume(struct device *dev)
+{
+	struct sdhci_host *host = dev_get_drvdata(dev);
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	int err;
+
+	err = clk_prepare_enable(pltfm_host->clk);
+	if (err)
+		return err;
+	return sdhci_resume_host(host);
+}
+
+#endif /* CONFIG_PM_SLEEP */
+
+static SIMPLE_DEV_PM_OPS(sdhci_brcmstb_pmops, sdhci_brcmstb_suspend,
+			sdhci_brcmstb_resume);
+
+static const 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_pltfm_data sdhci_brcmstb_pdata = {
+	.ops = &sdhci_brcmstb_ops,
+};
+
+static int sdhci_brcmstb_probe(struct platform_device *pdev)
+{
+	struct sdhci_host *host;
+	struct sdhci_pltfm_host *pltfm_host;
+	struct clk *clk;
+	int res;
+
+	clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(clk)) {
+		dev_err(&pdev->dev, "Clock not found in Device Tree\n");
+		clk = NULL;
+	}
+	res = clk_prepare_enable(clk);
+	if (res)
+		return res;
+
+	host = sdhci_pltfm_init(pdev, &sdhci_brcmstb_pdata, 0);
+	if (IS_ERR(host)) {
+		res = PTR_ERR(host);
+		goto err_clk;
+	}
+
+	/* Enable MMC_CAP2_HC_ERASE_SZ for better max discard calculations */
+	host->mmc->caps2 |= MMC_CAP2_HC_ERASE_SZ;
+
+	sdhci_get_of_property(pdev);
+	mmc_of_parse(host->mmc);
+
+	/*
+	 * 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);
+	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 |
+		SDHCI_QUIRK_BROKEN_TIMEOUT_VAL;
+
+	res = sdhci_add_host(host);
+	if (res)
+		goto err;
+
+	pltfm_host = sdhci_priv(host);
+	pltfm_host->clk = clk;
+	return res;
+
+err:
+	sdhci_pltfm_free(pdev);
+err_clk:
+	clk_disable_unprepare(clk);
+	return res;
+}
+
+static const struct of_device_id sdhci_brcm_of_match[] = {
+	{ .compatible = "brcm,bcm7425-sdhci" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, sdhci_brcm_of_match);
+
+static struct platform_driver sdhci_brcmstb_driver = {
+	.driver		= {
+		.name	= "sdhci-brcmstb",
+		.owner	= THIS_MODULE,
+		.pm	= &sdhci_brcmstb_pmops,
+		.of_match_table = of_match_ptr(sdhci_brcm_of_match),
+	},
+	.probe		= sdhci_brcmstb_probe,
+	.remove		= sdhci_pltfm_unregister,
+};
+
+module_platform_driver(sdhci_brcmstb_driver);
+
+MODULE_DESCRIPTION("SDHCI driver for Broadcom BRCMSTB SoCs");
+MODULE_AUTHOR("Broadcom");
+MODULE_LICENSE("GPL v2");