[PATCHv4 6/6] mmc: dw_mmc: Add support DW SD/MMC driver on SOCFPGA

[dinguyen@altera.com (dinguyen at altera.com)]

From: Dinh Nguyen <dinguyen@altera.com>

Add platform specific functionality for the DW SD/MMC driver for
SoCFPGA. Move SDMMC_CMD_USE_HOLD_REG to dw_mmc.h so other platforms
can use this define.

Signed-off-by: Dinh Nguyen <dinguyen@altera.com>
CC: Seungwon Jeon <tgih.jun@samsung.com>
CC: Jaehoon Chung <jh80.chung@samsung.com>
CC: Arnd Bergmann <arnd@arndb.de>
CC: Olof Johansson <olof@lixom.net>
CC: Pavel Machek <pavel@denx.de>
CC: linux-mmc at vger.kernel.org

v4:
- Fix up SYSMGR_SDMMC_CTRL_SET macro

v3:
- Addressed comments from Seugwon, Jaehoon, and Pavel
- Use clk_disable_unprepare/clk_prepare_enable

v2:
- Use syscon and regmap
- Avoid divide by zero
- Remove the need to set PWR_EN
---
 drivers/mmc/host/Kconfig          |    8 +++
 drivers/mmc/host/Makefile         |    1 +
 drivers/mmc/host/dw_mmc-exynos.c  |    2 -
 drivers/mmc/host/dw_mmc-socfpga.c |  138 +++++++++++++++++++++++++++++++++++++
 drivers/mmc/host/dw_mmc.h         |    1 +
 5 files changed, 148 insertions(+), 2 deletions(-)
 create mode 100644 drivers/mmc/host/dw_mmc-socfpga.c

diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index 9ab8f8d..1be2289 100644
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -556,6 +556,14 @@ config MMC_DW_EXYNOS
 	  Synopsys DesignWare Memory Card Interface driver. Select this option
 	  for platforms based on Exynos4 and Exynos5 SoC's.
 
+config MMC_DW_SOCFPGA
+	tristate "SOCFPGA specific extensions for Synopsys DW Memory Card Interface"
+	depends on MMC_DW
+	select MMC_DW_PLTFM
+	help
+	  This selects support for Altera SoCFPGA specific extensions to the
+	  Synopsys DesignWare Memory Card Interface driver.
+
 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 cd32280..67718c1 100644
--- a/drivers/mmc/host/Makefile
+++ b/drivers/mmc/host/Makefile
@@ -42,6 +42,7 @@ obj-$(CONFIG_SDH_BFIN)		+= bfin_sdh.o
 obj-$(CONFIG_MMC_DW)		+= dw_mmc.o
 obj-$(CONFIG_MMC_DW_PLTFM)	+= dw_mmc-pltfm.o
 obj-$(CONFIG_MMC_DW_EXYNOS)	+= dw_mmc-exynos.o
+obj-$(CONFIG_MMC_DW_SOCFPGA)	+= dw_mmc-socfpga.o
 obj-$(CONFIG_MMC_DW_PCI)	+= dw_mmc-pci.o
 obj-$(CONFIG_MMC_SH_MMCIF)	+= sh_mmcif.o
 obj-$(CONFIG_MMC_JZ4740)	+= jz4740_mmc.o
diff --git a/drivers/mmc/host/dw_mmc-exynos.c b/drivers/mmc/host/dw_mmc-exynos.c
index f013e7e..866edef 100644
--- a/drivers/mmc/host/dw_mmc-exynos.c
+++ b/drivers/mmc/host/dw_mmc-exynos.c
@@ -31,8 +31,6 @@
 					SDMMC_CLKSEL_CCLK_DRIVE(y) |	\
 					SDMMC_CLKSEL_CCLK_DIVIDER(z))
 
-#define SDMMC_CMD_USE_HOLD_REG		BIT(29)
-
 #define EXYNOS4210_FIXED_CIU_CLK_DIV	2
 #define EXYNOS4412_FIXED_CIU_CLK_DIV	4
 
diff --git a/drivers/mmc/host/dw_mmc-socfpga.c b/drivers/mmc/host/dw_mmc-socfpga.c
new file mode 100644
index 0000000..4c19fd8
--- /dev/null
+++ b/drivers/mmc/host/dw_mmc-socfpga.c
@@ -0,0 +1,138 @@
+/*
+ * Altera SoCFPGA Specific Extensions for Synopsys DW Multimedia Card Interface driver
+ *
+ *  Copyright (C) 2012, Samsung Electronics Co., Ltd.
+ *  Copyright (C) 2013 Altera Corporation
+ *
+ * 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.
+ *
+ * Taken from dw_mmc-exynos.c
+ */
+#include <linux/clk.h>
+#include <linux/mfd/syscon.h>
+#include <linux/mmc/host.h>
+#include <linux/mmc/dw_mmc.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#include "dw_mmc.h"
+#include "dw_mmc-pltfm.h"
+
+#define SYSMGR_SDMMCGRP_CTRL_OFFSET		0x108
+#define DRV_CLK_PHASE_SHIFT_SEL_MASK	0x7
+#define SYSMGR_SDMMC_CTRL_SET(smplsel, drvsel)          \
+	((((smplsel) & 0x7) << 3) | (((drvsel) & 0x7) << 0))
+
+/* SOCFPGA implementation specific driver private data */
+struct dw_mci_socfpga_priv_data {
+	u8	ciu_div; /* card interface unit divisor */
+	u32	hs_timing; /* bitmask for CIU clock phase shift */
+	struct regmap   *sysreg; /* regmap for system manager register */
+};
+
+static int dw_mci_socfpga_priv_init(struct dw_mci *host)
+{
+	struct dw_mci_socfpga_priv_data *priv;
+
+	priv = devm_kzalloc(host->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv) {
+		dev_err(host->dev, "mem alloc failed for private data\n");
+		return -ENOMEM;
+	}
+
+	priv->sysreg = syscon_regmap_lookup_by_compatible("altr,sys-mgr");
+	if (IS_ERR(priv->sysreg)) {
+		dev_err(host->dev, "regmap for altr,sys-mgr lookup failed.\n");
+		return PTR_ERR(priv->sysreg);
+	}
+	host->priv = priv;
+
+	return 0;
+}
+
+static int dw_mci_socfpga_setup_clock(struct dw_mci *host)
+{
+	struct dw_mci_socfpga_priv_data *priv = host->priv;
+
+	clk_disable_unprepare(host->ciu_clk);
+	regmap_write(priv->sysreg, SYSMGR_SDMMCGRP_CTRL_OFFSET, priv->hs_timing);
+	clk_prepare_enable(host->ciu_clk);
+
+	host->bus_hz /= (priv->ciu_div + 1);
+	return 0;
+}
+
+static void dw_mci_socfpga_prepare_command(struct dw_mci *host, u32 *cmdr)
+{
+	struct dw_mci_socfpga_priv_data *priv = host->priv;
+
+	if (priv->hs_timing & DRV_CLK_PHASE_SHIFT_SEL_MASK)
+		*cmdr |= SDMMC_CMD_USE_HOLD_REG;
+}
+
+static int dw_mci_socfpga_parse_dt(struct dw_mci *host)
+{
+	struct dw_mci_socfpga_priv_data *priv = host->priv;
+	struct device_node *np = host->dev->of_node;
+	u32 timing[2];
+	u32 div = 0;
+	int ret;
+
+	ret = of_property_read_u32(np, "altr,dw-mshc-ciu-div", &div);
+	if (ret)
+		dev_info(host->dev, "No dw-mshc-ciu-div specified, assuming 1");
+	priv->ciu_div = div;
+
+	ret = of_property_read_u32_array(np,
+			"altr,dw-mshc-sdr-timing", timing, 2);
+	if (ret)
+		return ret;
+
+	priv->hs_timing = SYSMGR_SDMMC_CTRL_SET(timing[0], timing[1]);
+	return 0;
+}
+
+static const struct dw_mci_drv_data socfpga_drv_data = {
+	.init			= dw_mci_socfpga_priv_init,
+	.setup_clock		= dw_mci_socfpga_setup_clock,
+	.prepare_command	= dw_mci_socfpga_prepare_command,
+	.parse_dt		= dw_mci_socfpga_parse_dt,
+};
+
+static const struct of_device_id dw_mci_socfpga_match[] = {
+	{ .compatible = "altr,socfpga-dw-mshc",
+			.data = &socfpga_drv_data, },
+	{},
+};
+MODULE_DEVICE_TABLE(of, dw_mci_socfpga_match);
+
+int dw_mci_socfpga_probe(struct platform_device *pdev)
+{
+	const struct dw_mci_drv_data *drv_data;
+	const struct of_device_id *match;
+
+	match = of_match_node(dw_mci_socfpga_match, pdev->dev.of_node);
+	drv_data = match->data;
+	return dw_mci_pltfm_register(pdev, drv_data);
+}
+
+static struct platform_driver dw_mci_socfpga_pltfm_driver = {
+	.probe		= dw_mci_socfpga_probe,
+	.remove		= __exit_p(dw_mci_pltfm_remove),
+	.driver		= {
+		.name		= "dwmmc_socfpga",
+		.of_match_table	= of_match_ptr(dw_mci_socfpga_match),
+		.pm		= &dw_mci_pltfm_pmops,
+	},
+};
+
+module_platform_driver(dw_mci_socfpga_pltfm_driver);
+
+MODULE_DESCRIPTION("Altera SOCFPGA Specific DW-MSHC Driver Extension");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:dwmmc-socfpga");
diff --git a/drivers/mmc/host/dw_mmc.h b/drivers/mmc/host/dw_mmc.h
index 0b74189..3700cb2 100644
--- a/drivers/mmc/host/dw_mmc.h
+++ b/drivers/mmc/host/dw_mmc.h
@@ -111,6 +111,7 @@
 #define SDMMC_INT_ERROR			0xbfc2
 /* Command register defines */
 #define SDMMC_CMD_START			BIT(31)
+#define SDMMC_CMD_USE_HOLD_REG	BIT(29)
 #define SDMMC_CMD_CCS_EXP		BIT(23)
 #define SDMMC_CMD_CEATA_RD		BIT(22)
 #define SDMMC_CMD_UPD_CLK		BIT(21)
-- 
1.7.9.5