drivers: mmc: Add sdhci driver for Broadcom iProc platform

Add SDHCI driver for iProc family of Broadcom devices.

Signed-off-by: Corneliu Doban <corneliu.doban@broadcom.com>
Signed-off-by: Pramod Kumar <pramod.kumar@broadcom.com>
Signed-off-by: Pavithra Ravi <pavithra.ravi@broadcom.com>
Signed-off-by: Bharat Kumar Reddy Gooty <bharat.gooty@broadcom.com>
Signed-off-by: Vladimir Olovyannikov <vladimir.olovyannikov@broadcom.com>
Signed-off-by: Arun Parameswaran <arun.parameswaran@broadcom.com>

arch/arm/include/asm/iproc-common/iproc_sdhci.h

@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: <SPDX License Expression> */
+/*
+ * Copyright 2019 Broadcom
+ *
+ */
+
+#ifndef __IPROC_SDHCI_H
+#define __IPROC_SDHCI_H
+
+int iproc_sdhci_init(int dev_index, u32 quirks);
+
+#endif

drivers/mmc/Kconfig

@@ -489,6 +489,17 @@ config MMC_SDHCI_AM654
 	  Support for Secure Digital Host Controller Interface (SDHCI)
 	  controllers present on TI's AM654 SOCs.
 
+config MMC_SDHCI_IPROC
+	bool "SDHCI support for the iProc SD/MMC Controller"
+	depends on MMC_SDHCI
+	help
+	  This selects the iProc SD/MMC controller.
+
+	  If you have a Broadcom IPROC platform with SD or MMC devices,
+	  say Y or M here.
+
+	  If unsure, say N.
+
 config MMC_SDHCI_KONA
 	bool "SDHCI support on Broadcom KONA platform"
 	depends on MMC_SDHCI

drivers/mmc/Makefile

@@ -52,6 +52,7 @@ obj-$(CONFIG_MMC_SDHCI_BCM2835)		+= bcm2835_sdhci.o
 obj-$(CONFIG_MMC_SDHCI_BCMSTB)		+= bcmstb_sdhci.o
 obj-$(CONFIG_MMC_SDHCI_CADENCE)		+= sdhci-cadence.o
 obj-$(CONFIG_MMC_SDHCI_AM654)		+= am654_sdhci.o
+obj-$(CONFIG_MMC_SDHCI_IPROC)		+= iproc_sdhci.o
 obj-$(CONFIG_MMC_SDHCI_KONA)		+= kona_sdhci.o
 obj-$(CONFIG_MMC_SDHCI_MSM)		+= msm_sdhci.o
 obj-$(CONFIG_MMC_SDHCI_MV)		+= mv_sdhci.o

drivers/mmc/iproc_sdhci.c

@@ -0,0 +1,247 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2019 Broadcom.
+ *
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <malloc.h>
+#include <sdhci.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+struct sdhci_iproc_host {
+	struct sdhci_host host;
+	u32 shadow_cmd;
+	u32 shadow_blk;
+};
+
+#define REG_OFFSET_IN_BITS(reg) ((reg) << 3 & 0x18)
+
+static inline struct sdhci_iproc_host *to_iproc(struct sdhci_host *host)
+{
+	return (struct sdhci_iproc_host *)host;
+}
+
+#ifdef CONFIG_MMC_SDHCI_IO_ACCESSORS
+static u32 sdhci_iproc_readl(struct sdhci_host *host, int reg)
+{
+	u32 val = readl(host->ioaddr + reg);
+#ifdef CONFIG_MMC_SDHCI_IO_ACCESSORS_TRACE
+	printf("%s %d: readl [0x%02x] 0x%08x\n",
+	       host->name, host->index, reg, val);
+#endif
+	return val;
+}
+
+static u16 sdhci_iproc_readw(struct sdhci_host *host, int reg)
+{
+	u32 val = sdhci_iproc_readl(host, (reg & ~3));
+	u16 word = val >> REG_OFFSET_IN_BITS(reg) & 0xffff;
+	return word;
+}
+
+static u8 sdhci_iproc_readb(struct sdhci_host *host, int reg)
+{
+	u32 val = sdhci_iproc_readl(host, (reg & ~3));
+	u8 byte = val >> REG_OFFSET_IN_BITS(reg) & 0xff;
+	return byte;
+}
+
+static void sdhci_iproc_writel(struct sdhci_host *host, u32 val, int reg)
+{
+	u32 clock = 0;
+#ifdef CONFIG_MMC_SDHCI_IO_ACCESSORS_TRACE
+	printf("%s %d: writel [0x%02x] 0x%08x\n",
+	       host->name, host->index, reg, val);
+#endif
+	writel(val, host->ioaddr + reg);
+
+	if (host->mmc)
+		clock = host->mmc->clock;
+	if (clock <= 400000) {
+		/* Round up to micro-second four SD clock delay */
+		if (clock)
+			udelay((4 * 1000000 + clock - 1) / clock);
+		else
+			udelay(10);
+	}
+}
+
+/*
+ * The Arasan has a bugette whereby it may lose the content of successive
+ * writes to the same register that are within two SD-card clock cycles of
+ * each other (a clock domain crossing problem). The data
+ * register does not have this problem, which is just as well - otherwise we'd
+ * have to nobble the DMA engine too.
+ *
+ * This wouldn't be a problem with the code except that we can only write the
+ * controller with 32-bit writes.  So two different 16-bit registers are
+ * written back to back creates the problem.
+ *
+ * In reality, this only happens when SDHCI_BLOCK_SIZE and SDHCI_BLOCK_COUNT
+ * are written followed by SDHCI_TRANSFER_MODE and SDHCI_COMMAND.
+ * The BLOCK_SIZE and BLOCK_COUNT are meaningless until a command issued so
+ * the work around can be further optimized. We can keep shadow values of
+ * BLOCK_SIZE, BLOCK_COUNT, and TRANSFER_MODE until a COMMAND is issued.
+ * Then, write the BLOCK_SIZE+BLOCK_COUNT in a single 32-bit write followed
+ * by the TRANSFER+COMMAND in another 32-bit write.
+ */
+static void sdhci_iproc_writew(struct sdhci_host *host, u16 val, int reg)
+{
+	struct sdhci_iproc_host *iproc_host = to_iproc(host);
+	u32 word_shift = REG_OFFSET_IN_BITS(reg);
+	u32 mask = 0xffff << word_shift;
+	u32 oldval, newval;
+
+	if (reg == SDHCI_COMMAND) {
+		/* Write the block now as we are issuing a command */
+		if (iproc_host->shadow_blk != 0) {
+			sdhci_iproc_writel(host, iproc_host->shadow_blk,
+					   SDHCI_BLOCK_SIZE);
+			iproc_host->shadow_blk = 0;
+		}
+		oldval = iproc_host->shadow_cmd;
+	} else if (reg == SDHCI_BLOCK_SIZE || reg == SDHCI_BLOCK_COUNT) {
+		/* Block size and count are stored in shadow reg */
+		oldval = iproc_host->shadow_blk;
+	} else {
+		/* Read reg, all other registers are not shadowed */
+		oldval = sdhci_iproc_readl(host, (reg & ~3));
+	}
+	newval = (oldval & ~mask) | (val << word_shift);
+
+	if (reg == SDHCI_TRANSFER_MODE) {
+		/* Save the transfer mode until the command is issued */
+		iproc_host->shadow_cmd = newval;
+	} else if (reg == SDHCI_BLOCK_SIZE || reg == SDHCI_BLOCK_COUNT) {
+		/* Save the block info until the command is issued */
+		iproc_host->shadow_blk = newval;
+	} else {
+		/* Command or other regular 32-bit write */
+		sdhci_iproc_writel(host, newval, reg & ~3);
+	}
+}
+
+static void sdhci_iproc_writeb(struct sdhci_host *host, u8 val, int reg)
+{
+	u32 oldval = sdhci_iproc_readl(host, (reg & ~3));
+	u32 byte_shift = REG_OFFSET_IN_BITS(reg);
+	u32 mask = 0xff << byte_shift;
+	u32 newval = (oldval & ~mask) | (val << byte_shift);
+
+	sdhci_iproc_writel(host, newval, reg & ~3);
+}
+#endif
+
+static void sdhci_iproc_set_ios_post(struct sdhci_host *host)
+{
+	u32 ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
+
+	/* Reset UHS mode bits */
+	ctrl &= ~SDHCI_CTRL_UHS_MASK;
+
+	if (host->mmc->ddr_mode)
+		ctrl |= UHS_DDR50_BUS_SPEED;
+
+	sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2);
+}
+
+static struct sdhci_ops sdhci_platform_ops = {
+#ifdef CONFIG_MMC_SDHCI_IO_ACCESSORS
+	.read_l = sdhci_iproc_readl,
+	.read_w = sdhci_iproc_readw,
+	.read_b = sdhci_iproc_readb,
+	.write_l = sdhci_iproc_writel,
+	.write_w = sdhci_iproc_writew,
+	.write_b = sdhci_iproc_writeb,
+#endif
+	.set_ios_post = sdhci_iproc_set_ios_post,
+};
+
+struct iproc_sdhci_plat {
+	struct mmc_config cfg;
+	struct mmc mmc;
+};
+
+static int iproc_sdhci_probe(struct udevice *dev)
+{
+	struct mmc_uclass_priv *upriv = dev_get_uclass_priv(dev);
+	struct iproc_sdhci_plat *plat = dev_get_platdata(dev);
+	struct sdhci_host *host = dev_get_priv(dev);
+	struct sdhci_iproc_host *iproc_host;
+	int node = dev_of_offset(dev);
+	u32 f_min_max[2];
+	int ret;
+
+	iproc_host = (struct sdhci_iproc_host *)
+			malloc(sizeof(struct sdhci_iproc_host));
+	if (!iproc_host) {
+		printf("%s: sdhci host malloc fail!\n", __func__);
+		return -ENOMEM;
+	}
+	iproc_host->shadow_cmd = 0;
+	iproc_host->shadow_blk = 0;
+
+	host->name = dev->name;
+	host->ioaddr = (void *)devfdt_get_addr(dev);
+	host->voltages = MMC_VDD_165_195 |
+			 MMC_VDD_32_33 | MMC_VDD_33_34;
+	host->quirks = SDHCI_QUIRK_BROKEN_VOLTAGE;
+	host->host_caps = MMC_MODE_DDR_52MHz;
+	host->index = fdtdec_get_uint(gd->fdt_blob, node, "index", 0);
+	host->ops = &sdhci_platform_ops;
+	host->version = sdhci_readw(host, SDHCI_HOST_VERSION);
+	ret = fdtdec_get_int_array(gd->fdt_blob, dev_of_offset(dev),
+				   "clock-freq-min-max", f_min_max, 2);
+	if (ret) {
+		printf("sdhci: clock-freq-min-max not found\n");
+		return ret;
+	}
+	host->max_clk = f_min_max[1];
+	host->bus_width	= fdtdec_get_int(gd->fdt_blob,
+					 dev_of_offset(dev), "bus-width", 4);
+
+	/* Update host_caps for 8 bit bus width */
+	if (host->bus_width == 8)
+		host->host_caps |= MMC_MODE_8BIT;
+
+	memcpy(&iproc_host->host, host, sizeof(struct sdhci_host));
+
+	ret = sdhci_setup_cfg(&plat->cfg, &iproc_host->host,
+			      f_min_max[1], f_min_max[0]);
+	if (ret)
+		return ret;
+
+	iproc_host->host.mmc = &plat->mmc;
+	iproc_host->host.mmc->dev = dev;
+	iproc_host->host.mmc->priv = &iproc_host->host;
+	upriv->mmc = iproc_host->host.mmc;
+
+	return sdhci_probe(dev);
+}
+
+static int iproc_sdhci_bind(struct udevice *dev)
+{
+	struct iproc_sdhci_plat *plat = dev_get_platdata(dev);
+
+	return sdhci_bind(dev, &plat->mmc, &plat->cfg);
+}
+
+static const struct udevice_id iproc_sdhci_ids[] = {
+	{ .compatible = "brcm,iproc-sdhci" },
+	{ }
+};
+
+U_BOOT_DRIVER(iproc_sdhci_drv) = {
+	.name = "iproc_sdhci",
+	.id = UCLASS_MMC,
+	.of_match = iproc_sdhci_ids,
+	.ops = &sdhci_ops,
+	.bind = iproc_sdhci_bind,
+	.probe = iproc_sdhci_probe,
+	.priv_auto_alloc_size = sizeof(struct sdhci_host),
+	.platdata_auto_alloc_size = sizeof(struct iproc_sdhci_plat),
+};