[PATCH 1/2] mmc: dw_mmc-bluefield: Add driver extension

[Liming Sun]

This commit adds extension to the dw_mmc driver for Mellanox BlueField
SoC. It updates the UHS_REG_EXT register to bring up the eMMC card on
this SoC.

Signed-off-by: Liming Sun <lsun@xxxxxxxxxxxx>
---
 .../devicetree/bindings/mmc/bluefield-dw-mshc.txt  | 29 +++++++++
 drivers/mmc/host/Kconfig                           |  9 +++
 drivers/mmc/host/Makefile                          |  1 +
 drivers/mmc/host/dw_mmc-bluefield.c                | 72 ++++++++++++++++++++++
 4 files changed, 111 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mmc/bluefield-dw-mshc.txt
 create mode 100644 drivers/mmc/host/dw_mmc-bluefield.c

diff --git a/Documentation/devicetree/bindings/mmc/bluefield-dw-mshc.txt b/Documentation/devicetree/bindings/mmc/bluefield-dw-mshc.txt
new file mode 100644
index 0000000..ee0dd61
--- /dev/null
+++ b/Documentation/devicetree/bindings/mmc/bluefield-dw-mshc.txt
@@ -0,0 +1,29 @@
+* Mellanox Bluefield SoC specific extensions to the Synopsys Designware
+  Mobile Storage Host Controller
+
+Read synopsys-dw-mshc.txt for more details
+
+The Synopsys designware mobile storage host controller is used to interface
+a SoC with storage medium such as eMMC or SD/MMC cards. This file documents
+differences between the core Synopsys dw mshc controller properties described
+by synopsys-dw-mshc.txt and the properties used by the Mellanox Bluefield SoC
+specific extensions to the Synopsys Designware Mobile Storage Host Controller.
+
+Required Properties:
+
+* compatible: should be one of the following.
+  - "mellanox,bluefield-dw-mshc": for controllers with Mellanox Bluefield SoC
+    specific extensions.
+
+Example:
+
+	/* Mellanox Bluefield SoC MMC */
+	dwmmc0@4,0 {
+		compatible = "mellanox,bluefield-dw-mshc";
+		reg = <4 0x8000 0x400>;
+		interrupts = <32>;
+		fifo-depth = <0x100>;
+		clock-frequency = <24000000>;
+		bus-width = <8>;
+		cap-mmc-highspeed;
+	};
diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index 9589f9c..26ac6b5 100644
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -717,6 +717,15 @@ config MMC_DW_K3
 	  Synopsys DesignWare Memory Card Interface driver. Select this option
 	  for platforms based on Hisilicon K3 SoC's.
 
+config MMC_DW_BLUEFIELD
+	tristate "BlueField specific extensions for Synopsys DW Memory Card Interface"
+	depends on MMC_DW
+	select MMC_DW_PLTFM
+	help
+	  This selects support for Mellanox BlueField SoC specific extensions to
+	  the Synopsys DesignWare Memory Card Interface driver. Select this
+	  option for platforms based on Mellanox BlueField SoC's.
+
 config MMC_DW_PCI
 	tristate "Synopsys Designware MCI support on PCI bus"
 	depends on MMC_DW && PCI
diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
index 6aead24..267b3f1 100644
--- a/drivers/mmc/host/Makefile
+++ b/drivers/mmc/host/Makefile
@@ -55,6 +55,7 @@ obj-$(CONFIG_MMC_DW_K3)		+= dw_mmc-k3.o
 obj-$(CONFIG_MMC_DW_PCI)	+= dw_mmc-pci.o
 obj-$(CONFIG_MMC_DW_ROCKCHIP)	+= dw_mmc-rockchip.o
 obj-$(CONFIG_MMC_DW_ZX)		+= dw_mmc-zx.o
+obj-$(CONFIG_MMC_DW_BLUEFIELD)	+= dw_mmc-bluefield.o
 obj-$(CONFIG_MMC_SH_MMCIF)	+= sh_mmcif.o
 obj-$(CONFIG_MMC_JZ4740)	+= jz4740_mmc.o
 obj-$(CONFIG_MMC_VUB300)	+= vub300.o
diff --git a/drivers/mmc/host/dw_mmc-bluefield.c b/drivers/mmc/host/dw_mmc-bluefield.c
new file mode 100644
index 0000000..12067b1
--- /dev/null
+++ b/drivers/mmc/host/dw_mmc-bluefield.c
@@ -0,0 +1,72 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2018 Mellanox Technologies.
+ *
+ * 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; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/mmc/host.h>
+#include <linux/mmc/mmc.h>
+#include <linux/of.h>
+
+#include "dw_mmc.h"
+#include "dw_mmc-pltfm.h"
+
+static void dw_mci_bluefield_set_ios(struct dw_mci *host, struct mmc_ios *ios)
+{
+	u32 regs;
+
+	/* Set drive=4 (bit 29:23) and sample=2 (bit 22:16) in UHS_REG_EXT. */
+	regs = mci_readl(host, UHS_REG_EXT);
+	regs = (regs & ~0x3F100000 & ~0x7F0000) | (4 << 23) | (2 << 16);
+	mci_writel(host, UHS_REG_EXT, regs);
+}
+
+static const struct dw_mci_drv_data bluefield_drv_data = {
+	.set_ios		= dw_mci_bluefield_set_ios
+};
+
+static const struct of_device_id dw_mci_bluefield_match[] = {
+	{ .compatible = "mellanox,bluefield-dw-mshc",
+		.data = &bluefield_drv_data },
+	{},
+};
+MODULE_DEVICE_TABLE(of, dw_mci_bluefield_match);
+
+static int dw_mci_bluefield_probe(struct platform_device *pdev)
+{
+	const struct dw_mci_drv_data *drv_data = NULL;
+	const struct of_device_id *match;
+
+	if (pdev->dev.of_node) {
+		match = of_match_node(dw_mci_bluefield_match,
+				      pdev->dev.of_node);
+		drv_data = match->data;
+	}
+
+	return dw_mci_pltfm_register(pdev, drv_data);
+}
+
+static struct platform_driver dw_mci_bluefield_pltfm_driver = {
+	.probe		= dw_mci_bluefield_probe,
+	.remove		= dw_mci_pltfm_remove,
+	.driver		= {
+		.name		= "dwmmc_bluefield",
+		.of_match_table	= dw_mci_bluefield_match,
+		.pm		= &dw_mci_pltfm_pmops,
+	},
+};
+
+module_platform_driver(dw_mci_bluefield_pltfm_driver);
+
+MODULE_DESCRIPTION("BlueField DW Multimedia Card driver");
+MODULE_AUTHOR("Mellanox Technologies");
+MODULE_LICENSE("GPL v2");
-- 
1.8.3.1