ARC: dwmmc: Adding DesignWare MMC driver support for ARC devboards

Add the DM_MMC-compatible DesignWare MMC driver support for Synopsys
ARC devboards. It is created to switch ARC devboards to use DM_MMC.

It required information such as clocks (Bus Interface Unit clock,
Card Interface Unit clock) and SDIO bus width.

Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>

MAINTAINERS

@@ -74,6 +74,13 @@ L:	uboot-snps-arc@synopsys.com
 F:	doc/device-tree-bindings/gpio/snps,creg-gpio.txt
 F:	drivers/gpio/hsdk-creg-gpio.c
 
+ARC SYNOPSYS DW MMC EXTENSIONS
+M:	Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
+S:	Maintained
+L:	uboot-snps-arc@synopsys.com
+F:	doc/device-tree-bindings/mmc/snps,dw-mmc.txt
+F:	drivers/mmc/snps_dw_mmc.c
+
 ARM
 M:	Albert Aribaud <albert.u.boot@aribaud.net>
 S:	Maintained

doc/device-tree-bindings/mmc/snps,dw-mmc.txt

@@ -0,0 +1,33 @@
+Synopsys Designware Mobile Storage Host Controller extensions
+used in Synopsys ARC devboards
+
+Required Properties:
+
+* compatible: should be - "snps,dw-mshc".
+* bus-width: number of data lines connected to the controller.
+* clocks: from common clock binding: handle to biu and ciu clocks for the
+  bus interface unit clock and the card interface unit clock.
+* clock-names: from common clock binding: Shall be "biu" and "ciu".
+
+Optional properties:
+
+* fifo-depth: The maximum size of the tx/rx fifo's. If this property is not
+  specified, the default value of the fifo size is determined from the
+  controller registers.
+* fifo-mode: Don't use DMA.
+* max-frequency: Maximum operating clock frequency, driver uses 'ciu' clock
+  frequency if it is not set.
+
+Example:
+
+mmc0@f000a000 {
+	compatible = "snps,dw-mshc";
+	reg = <0xf000a000 0x400>;
+
+	bus-width = <4>;
+	fifo-depth = <256>;
+	clocks = <&mmcclk_biu>, <&mmcclk_ciu>;
+	clock-names = "biu", "ciu";
+	max-frequency = <25000000>;
+};
+

drivers/mmc/Kconfig

@@ -222,6 +222,16 @@ config MMC_DW_SOCFPGA
 	  Synopsys DesignWare Memory Card Interface driver. Select this option
 	  for platforms based on Altera SOCFPGA.
 
+config MMC_DW_SNPS
+	bool "Extensions for DW Memory Card Interface used in Synopsys ARC devboards"
+	depends on MMC_DW
+	depends on DM_MMC
+	depends on OF_CONTROL
+	depends on CLK
+	help
+	  This selects support for Synopsys DesignWare Memory Card Interface driver
+	  extensions used in various Synopsys ARC devboards.
+
 config MMC_MESON_GX
 	bool "Meson GX EMMC controller support"
 	depends on DM_MMC && BLK && ARCH_MESON

drivers/mmc/Makefile

@@ -24,6 +24,7 @@ obj-$(CONFIG_MMC_DW_EXYNOS)		+= exynos_dw_mmc.o
 obj-$(CONFIG_MMC_DW_K3)			+= hi6220_dw_mmc.o
 obj-$(CONFIG_MMC_DW_ROCKCHIP)		+= rockchip_dw_mmc.o
 obj-$(CONFIG_MMC_DW_SOCFPGA)		+= socfpga_dw_mmc.o
+obj-$(CONFIG_MMC_DW_SNPS)		+= snps_dw_mmc.o
 obj-$(CONFIG_FSL_ESDHC) += fsl_esdhc.o
 obj-$(CONFIG_FTSDC010) += ftsdc010_mci.o
 obj-$(CONFIG_GENERIC_ATMEL_MCI) += gen_atmel_mci.o

drivers/mmc/snps_dw_mmc.c

@@ -0,0 +1,199 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Synopsys DesignWare Multimedia Card Interface driver
+ * extensions used in various Synopsys ARC devboards.
+ *
+ * Copyright (C) 2019 Synopsys
+ * Author: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
+ */
+
+#include <common.h>
+#include <clk.h>
+#include <dm.h>
+#include <dwmmc.h>
+#include <errno.h>
+#include <fdtdec.h>
+#include <linux/libfdt.h>
+#include <linux/err.h>
+#include <malloc.h>
+
+#define CLOCK_MIN		400000	/*  400 kHz */
+#define FIFO_MIN		8
+#define FIFO_MAX		4096
+
+struct snps_dwmci_plat {
+	struct mmc_config	cfg;
+	struct mmc		mmc;
+};
+
+struct snps_dwmci_priv_data {
+	struct dwmci_host	host;
+	u32			f_max;
+};
+
+static int snps_dwmmc_clk_setup(struct udevice *dev)
+{
+	struct snps_dwmci_priv_data *priv = dev_get_priv(dev);
+	struct dwmci_host *host = &priv->host;
+
+	struct clk clk_ciu, clk_biu;
+	int ret;
+
+	ret = clk_get_by_name(dev, "ciu", &clk_ciu);
+	if (ret)
+		goto clk_err;
+
+	ret = clk_enable(&clk_ciu);
+	if (ret && ret != -ENOSYS && ret != -ENOTSUPP)
+		goto clk_err_ciu;
+
+	host->bus_hz = clk_get_rate(&clk_ciu);
+	if (host->bus_hz < CLOCK_MIN) {
+		ret = -EINVAL;
+		goto clk_err_ciu_dis;
+	}
+
+	ret = clk_get_by_name(dev, "biu", &clk_biu);
+	if (ret)
+		goto clk_err_ciu_dis;
+
+	ret = clk_enable(&clk_biu);
+	if (ret && ret != -ENOSYS && ret != -ENOTSUPP)
+		goto clk_err_biu;
+
+	return 0;
+
+clk_err_biu:
+	clk_free(&clk_biu);
+clk_err_ciu_dis:
+	clk_disable(&clk_ciu);
+clk_err_ciu:
+	clk_free(&clk_ciu);
+clk_err:
+	dev_err(dev, "failed to setup clocks, ret %d\n", ret);
+
+	return ret;
+}
+
+static int snps_dwmmc_ofdata_to_platdata(struct udevice *dev)
+{
+	struct snps_dwmci_priv_data *priv = dev_get_priv(dev);
+	struct dwmci_host *host = &priv->host;
+	u32 fifo_depth;
+	int ret;
+
+	host->ioaddr = devfdt_get_addr_ptr(dev);
+
+	/*
+	 * If fifo-depth is unset don't set fifoth_val - we will try to
+	 * auto detect it.
+	 */
+	ret = dev_read_u32(dev, "fifo-depth", &fifo_depth);
+	if (!ret) {
+		if (fifo_depth < FIFO_MIN || fifo_depth > FIFO_MAX)
+			return -EINVAL;
+
+		host->fifoth_val = MSIZE(0x2) |
+				   RX_WMARK(fifo_depth / 2 - 1) |
+				   TX_WMARK(fifo_depth / 2);
+	}
+
+	host->buswidth = dev_read_u32_default(dev, "bus-width", 4);
+	if (host->buswidth != 1 && host->buswidth != 4 && host->buswidth != 8)
+		return -EINVAL;
+
+	/*
+	 * If max-frequency is unset don't set priv->f_max - we will use
+	 * host->bus_hz in probe() instead.
+	 */
+	ret = dev_read_u32(dev, "max-frequency", &priv->f_max);
+	if (!ret && priv->f_max < CLOCK_MIN)
+		return -EINVAL;
+
+	host->fifo_mode = dev_read_bool(dev, "fifo-mode");
+	host->name = dev->name;
+	host->dev_index = 0;
+	host->priv = priv;
+
+	return 0;
+}
+
+int snps_dwmmc_getcd(struct udevice *dev)
+{
+	struct snps_dwmci_priv_data *priv = dev_get_priv(dev);
+	struct dwmci_host *host = &priv->host;
+
+	return !(dwmci_readl(host, DWMCI_CDETECT) & 1);
+}
+
+struct dm_mmc_ops snps_dwmci_dm_ops;
+
+static int snps_dwmmc_probe(struct udevice *dev)
+{
+#ifdef CONFIG_BLK
+	struct snps_dwmci_plat *plat = dev_get_platdata(dev);
+#endif
+	struct mmc_uclass_priv *upriv = dev_get_uclass_priv(dev);
+	struct snps_dwmci_priv_data *priv = dev_get_priv(dev);
+	struct dwmci_host *host = &priv->host;
+	unsigned int clock_max;
+	int ret;
+
+	/* Extend generic 'dm_dwmci_ops' with our 'getcd' implementation */
+	memcpy(&snps_dwmci_dm_ops, &dm_dwmci_ops, sizeof(struct dm_mmc_ops));
+	snps_dwmci_dm_ops.get_cd = snps_dwmmc_getcd;
+
+	ret = snps_dwmmc_clk_setup(dev);
+	if (ret)
+		return ret;
+
+	if (!priv->f_max)
+		clock_max = host->bus_hz;
+	else
+		clock_max = min_t(unsigned int, host->bus_hz, priv->f_max);
+
+#ifdef CONFIG_BLK
+	dwmci_setup_cfg(&plat->cfg, host, clock_max, CLOCK_MIN);
+	host->mmc = &plat->mmc;
+#else
+	ret = add_dwmci(host, clock_max, CLOCK_MIN);
+	if (ret)
+		return ret;
+#endif
+	host->mmc->priv = &priv->host;
+	upriv->mmc = host->mmc;
+	host->mmc->dev = dev;
+
+	return dwmci_probe(dev);
+}
+
+static int snps_dwmmc_bind(struct udevice *dev)
+{
+#ifdef CONFIG_BLK
+	struct snps_dwmci_plat *plat = dev_get_platdata(dev);
+	int ret;
+
+	ret = dwmci_bind(dev, &plat->mmc, &plat->cfg);
+	if (ret)
+		return ret;
+#endif
+
+	return 0;
+}
+
+static const struct udevice_id snps_dwmmc_ids[] = {
+	{ .compatible = "snps,dw-mshc" },
+	{ }
+};
+
+U_BOOT_DRIVER(snps_dwmmc_drv) = {
+	.name				= "snps_dw_mmc",
+	.id				= UCLASS_MMC,
+	.of_match			= snps_dwmmc_ids,
+	.ofdata_to_platdata		= snps_dwmmc_ofdata_to_platdata,
+	.ops				= &snps_dwmci_dm_ops,
+	.bind				= snps_dwmmc_bind,
+	.probe				= snps_dwmmc_probe,
+	.priv_auto_alloc_size		= sizeof(struct snps_dwmci_priv_data),
+	.platdata_auto_alloc_size	= sizeof(struct snps_dwmci_plat),
+};