arc: add AXS101 board support

AXS101 is a new generation of devlopment boards from Synopsys that houses
ASIC with ARC700 and lots of DesignWare peripherals:

 * DW APB UART
 * DW Mobile Storage (MMC/SD)
 * DW I2C
 * DW GMAC

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

Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Francois Bedard <fbedard@synopsys.com>
Cc: Wolfgang Denk <wd@denx.de>
Cc: Heiko Schocher <hs@denx.de>
diff --git a/board/synopsys/axs101/nand.c b/board/synopsys/axs101/nand.c
new file mode 100644
index 0000000..8672803
--- /dev/null
+++ b/board/synopsys/axs101/nand.c
@@ -0,0 +1,226 @@
+/*
+ * Copyright (C) 2013-2014 Synopsys, Inc. All rights reserved.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <bouncebuf.h>
+#include <common.h>
+#include <malloc.h>
+#include <nand.h>
+#include <asm/io.h>
+
+#define BUS_WIDTH	8		/* AXI data bus width in bytes	*/
+
+/* DMA buffer descriptor bits & masks */
+#define BD_STAT_OWN			(1 << 31)
+#define BD_STAT_BD_FIRST		(1 << 3)
+#define BD_STAT_BD_LAST			(1 << 2)
+#define BD_SIZES_BUFFER1_MASK		0xfff
+
+#define BD_STAT_BD_COMPLETE	(BD_STAT_BD_FIRST | BD_STAT_BD_LAST)
+
+/* Controller command flags */
+#define B_WFR		(1 << 19)	/* 1b - Wait for ready		*/
+#define B_LC		(1 << 18)	/* 1b - Last cycle		*/
+#define B_IWC		(1 << 13)	/* 1b - Interrupt when complete	*/
+
+/* NAND cycle types */
+#define B_CT_ADDRESS	(0x0 << 16)	/* Address operation		*/
+#define B_CT_COMMAND	(0x1 << 16)	/* Command operation		*/
+#define B_CT_WRITE	(0x2 << 16)	/* Write operation		*/
+#define B_CT_READ	(0x3 << 16)	/* Write operation		*/
+
+enum nand_isr_t {
+	NAND_ISR_DATAREQUIRED = 0,
+	NAND_ISR_TXUNDERFLOW,
+	NAND_ISR_TXOVERFLOW,
+	NAND_ISR_DATAAVAILABLE,
+	NAND_ISR_RXUNDERFLOW,
+	NAND_ISR_RXOVERFLOW,
+	NAND_ISR_TXDMACOMPLETE,
+	NAND_ISR_RXDMACOMPLETE,
+	NAND_ISR_DESCRIPTORUNAVAILABLE,
+	NAND_ISR_CMDDONE,
+	NAND_ISR_CMDAVAILABLE,
+	NAND_ISR_CMDERROR,
+	NAND_ISR_DATATRANSFEROVER,
+	NAND_ISR_NONE
+};
+
+enum nand_regs_t {
+	AC_FIFO = 0,		/* address and command fifo */
+	IDMAC_BDADDR = 0x18,	/* idmac descriptor list base address */
+	INT_STATUS = 0x118,	/* interrupt status register */
+	INT_CLR_STATUS = 0x120,	/* interrupt clear status register */
+};
+
+struct nand_bd {
+	uint32_t status;	/* DES0 */
+	uint32_t sizes;		/* DES1 */
+	uint32_t buffer_ptr0;	/* DES2 */
+	uint32_t buffer_ptr1;	/* DES3 */
+};
+
+#define NAND_REG_WRITE(r, v)	writel(v, CONFIG_SYS_NAND_BASE + r)
+#define NAND_REG_READ(r)	readl(CONFIG_SYS_NAND_BASE + r)
+
+static struct nand_bd *bd;	/* DMA buffer descriptors	*/
+
+/**
+ * axs101_nand_write_buf -  write buffer to chip
+ * @mtd:	MTD device structure
+ * @buf:	data buffer
+ * @len:	number of bytes to write
+ */
+static uint32_t nand_flag_is_set(uint32_t flag)
+{
+	uint32_t reg = NAND_REG_READ(INT_STATUS);
+
+	if (reg & (1 << NAND_ISR_CMDERROR))
+		return 0;
+
+	if (reg & (1 << flag)) {
+		NAND_REG_WRITE(INT_CLR_STATUS, 1 << flag);
+		return 1;
+	}
+
+	return 0;
+}
+
+/**
+ * axs101_nand_write_buf -  write buffer to chip
+ * @mtd:	MTD device structure
+ * @buf:	data buffer
+ * @len:	number of bytes to write
+ */
+static void axs101_nand_write_buf(struct mtd_info *mtd, const u_char *buf,
+				   int len)
+{
+	struct bounce_buffer bbstate;
+
+	bounce_buffer_start(&bbstate, (void *)buf, len, GEN_BB_READ);
+
+	/* Setup buffer descriptor */
+	writel(BD_STAT_OWN | BD_STAT_BD_COMPLETE, &bd->status);
+	writel(ALIGN(len, BUS_WIDTH) & BD_SIZES_BUFFER1_MASK, &bd->sizes);
+	writel(bbstate.bounce_buffer, &bd->buffer_ptr0);
+	writel(0, &bd->buffer_ptr1);
+
+	/* Issue "write" command */
+	NAND_REG_WRITE(AC_FIFO, B_CT_WRITE | B_WFR | B_IWC | B_LC | (len-1));
+
+	/* Wait for NAND command and DMA to complete */
+	while (!nand_flag_is_set(NAND_ISR_CMDDONE))
+		;
+	while (!nand_flag_is_set(NAND_ISR_TXDMACOMPLETE))
+		;
+
+	bounce_buffer_stop(&bbstate);
+}
+
+/**
+ * axs101_nand_read_buf -  read chip data into buffer
+ * @mtd:	MTD device structure
+ * @buf:	buffer to store data
+ * @len:	number of bytes to read
+ */
+static void axs101_nand_read_buf(struct mtd_info *mtd, u_char *buf, int len)
+{
+	struct bounce_buffer bbstate;
+
+	bounce_buffer_start(&bbstate, buf, len, GEN_BB_WRITE);
+
+	/* Setup buffer descriptor */
+	writel(BD_STAT_OWN | BD_STAT_BD_COMPLETE, &bd->status);
+	writel(ALIGN(len, BUS_WIDTH) & BD_SIZES_BUFFER1_MASK, &bd->sizes);
+	writel(bbstate.bounce_buffer, &bd->buffer_ptr0);
+	writel(0, &bd->buffer_ptr1);
+
+	/* Issue "read" command */
+	NAND_REG_WRITE(AC_FIFO, B_CT_READ | B_WFR | B_IWC | B_LC | (len - 1));
+
+	/* Wait for NAND command and DMA to complete */
+	while (!nand_flag_is_set(NAND_ISR_CMDDONE))
+		;
+	while (!nand_flag_is_set(NAND_ISR_RXDMACOMPLETE))
+		;
+
+	bounce_buffer_stop(&bbstate);
+}
+
+/**
+ * axs101_nand_read_byte -  read one byte from the chip
+ * @mtd:	MTD device structure
+ */
+static u_char axs101_nand_read_byte(struct mtd_info *mtd)
+{
+	u8 byte;
+
+	axs101_nand_read_buf(mtd, (uchar *)&byte, sizeof(byte));
+	return byte;
+}
+
+/**
+ * axs101_nand_read_word -  read one word from the chip
+ * @mtd:	MTD device structure
+ */
+static u16 axs101_nand_read_word(struct mtd_info *mtd)
+{
+	u16 word;
+
+	axs101_nand_read_buf(mtd, (uchar *)&word, sizeof(word));
+	return word;
+}
+
+/**
+ * axs101_nand_hwcontrol - NAND control functions wrapper.
+ * @mtd:	MTD device structure
+ * @cmd:	Command
+ */
+static void axs101_nand_hwcontrol(struct mtd_info *mtdinfo, int cmd,
+				   unsigned int ctrl)
+{
+	if (cmd == NAND_CMD_NONE)
+		return;
+
+	cmd = cmd & 0xff;
+
+	switch (ctrl & (NAND_ALE | NAND_CLE)) {
+	/* Address */
+	case NAND_ALE:
+		cmd |= B_CT_ADDRESS;
+		break;
+
+	/* Command */
+	case NAND_CLE:
+		cmd |= B_CT_COMMAND | B_WFR;
+
+		break;
+
+	default:
+		debug("%s: unknown ctrl %#x\n", __func__, ctrl);
+	}
+
+	NAND_REG_WRITE(AC_FIFO, cmd | B_LC);
+	while (!nand_flag_is_set(NAND_ISR_CMDDONE))
+		;
+}
+
+int board_nand_init(struct nand_chip *nand)
+{
+	bd = (struct nand_bd *)memalign(ARCH_DMA_MINALIGN,
+					sizeof(struct nand_bd));
+
+	/* Set buffer descriptor address in IDMAC */
+	NAND_REG_WRITE(IDMAC_BDADDR, bd);
+
+	nand->ecc.mode = NAND_ECC_SOFT;
+	nand->cmd_ctrl = axs101_nand_hwcontrol;
+	nand->read_byte = axs101_nand_read_byte;
+	nand->read_word = axs101_nand_read_word;
+	nand->write_buf = axs101_nand_write_buf;
+	nand->read_buf = axs101_nand_read_buf;
+
+	return 0;
+}