mt8173: add SPI NOR support

BRANCH=none
BUG=none
TEST=boot oak to kernel on rev1

Change-Id: I0773c81398df445aec16bcfcd0c5a8fe5a588b5c
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: ae15c42c2f7d9c2a716e5b6098d85e17279f5eae
Original-Change-Id: I65abf810d35ae5e7156cf6f5730117e690183d18
Original-Signed-off-by: mtk05962 <bayi.cheng@mediatek.com>
Original-Reviewed-on: https://chromium-review.googlesource.com/292693
Original-Commit-Ready: Yidi Lin <yidi.lin@mediatek.com>
Original-Tested-by: Yidi Lin <yidi.lin@mediatek.com>
Original-Reviewed-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://review.coreboot.org/13102
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>

src/soc/mediatek/mt8173/flash_controller.c

@@ -0,0 +1,184 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2015 MediaTek Inc.
+ *
+ * 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; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+/* NOR Flash is clocked with 26MHz, from CLK26M -> TOP_SPINFI_IFR */
+
+#include <arch/io.h>
+#include <assert.h>
+#include <console/console.h>
+#include <spi_flash.h>
+#include <spi-generic.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <timer.h>
+#include <soc/flash_controller.h>
+
+#define get_nth_byte(d, n)	((d >> (8 * n)) & 0xff)
+
+static int polling_cmd(u32 val)
+{
+	struct stopwatch sw;
+
+	stopwatch_init_usecs_expire(&sw, SFLASH_POLLINGREG_US);
+
+	while ((read32(&mt8173_nor->cmd) & val) != 0) {
+		if (stopwatch_expired(&sw))
+			return -1;
+	}
+
+	return 0;
+}
+
+static int mt8173_nor_execute_cmd(u8 cmdval)
+{
+	u8 val = cmdval & ~(SFLASH_AUTOINC);
+
+	write8(&mt8173_nor->cmd, cmdval);
+	return polling_cmd(val);
+}
+
+static int sflashhw_read_flash_status(u8 *value)
+{
+	if (mt8173_nor_execute_cmd(SFLASH_READSTATUS))
+		return -1;
+
+	*value = read8(&mt8173_nor->rdsr);
+	return 0;
+}
+
+static int wait_for_write_done(void)
+{
+	struct stopwatch sw;
+	u8 reg;
+
+	stopwatch_init_usecs_expire(&sw, SFLASH_POLLINGREG_US);
+
+	while (sflashhw_read_flash_status(&reg) == 0) {
+		if (!(reg & SFLASH_WRITE_IN_PROGRESS))
+			return 0;
+		if (stopwatch_expired(&sw))
+			return -1;
+	}
+
+	return -1;
+}
+
+/* set serial flash program address */
+static void set_sfpaddr(u32 addr)
+{
+	write8(&mt8173_nor->radr[2], get_nth_byte(addr, 2));
+	write8(&mt8173_nor->radr[1], get_nth_byte(addr, 1));
+	write8(&mt8173_nor->radr[0], get_nth_byte(addr, 0));
+}
+
+static int sector_erase(int offset)
+{
+	if (wait_for_write_done())
+		return -1;
+
+	write8(&mt8173_nor->prgdata[5], SFLASH_OP_WREN);
+	write8(&mt8173_nor->cnt, 8);
+	mt8173_nor_execute_cmd(SFLASH_PRG_CMD);
+
+	write8(&mt8173_nor->prgdata[5], SECTOR_ERASE_CMD);
+	write8(&mt8173_nor->prgdata[4], get_nth_byte(offset, 2));
+	write8(&mt8173_nor->prgdata[3], get_nth_byte(offset, 1));
+	write8(&mt8173_nor->prgdata[2], get_nth_byte(offset, 0));
+	write8(&mt8173_nor->cnt, 32);
+	mt8173_nor_execute_cmd(SFLASH_PRG_CMD);
+
+	if (wait_for_write_done())
+		return -1;
+
+	return 0;
+}
+
+unsigned int spi_crop_chunk(unsigned int cmd_len, unsigned int buf_len)
+{
+	return min(65535, buf_len);
+}
+
+static int nor_read(struct spi_flash *flash, u32 addr, size_t len, void *buf)
+{
+	u8 *buffer = (u8 *)buf;
+
+	set_sfpaddr(addr);
+	while (len) {
+		if (mt8173_nor_execute_cmd(SFLASH_RD_TRIGGER | SFLASH_AUTOINC))
+			return -1;
+
+		*buffer++ = read8(&mt8173_nor->rdata);
+		len--;
+	}
+	return 0;
+}
+
+static int nor_write(struct spi_flash *flash, u32 addr, size_t len,
+		       const void *buf)
+{
+	const u8 *buffer = (const u8 *)buf;
+
+	set_sfpaddr(addr);
+	while (len) {
+		write8(&mt8173_nor->wdata, *buffer);
+		if (mt8173_nor_execute_cmd(SFLASH_WR_TRIGGER | SFLASH_AUTOINC))
+			return -1;
+
+		if (wait_for_write_done())
+			return -1;
+		buffer++;
+		len--;
+	}
+	return 0;
+}
+
+static int nor_erase(struct spi_flash *flash, u32 offset, size_t len)
+{
+	int sector_start = offset;
+	int sector_num = (u32)len / flash->sector_size;
+
+	while (sector_num) {
+		if (!sector_erase(sector_start)) {
+			sector_start += flash->sector_size;
+			sector_num--;
+		} else {
+			printk(BIOS_WARNING, "Erase failed at 0x%x!\n",
+			       sector_start);
+			return -1;
+		}
+	}
+	return 0;
+}
+
+struct spi_flash *mt8173_nor_flash_probe(struct spi_slave *spi)
+{
+	static struct spi_flash flash = {0};
+
+	if (flash.spi)
+		return &flash;
+
+	write32(&mt8173_nor->wrprot, SFLASH_COMMAND_ENABLE);
+	flash.spi = spi;
+	flash.name = "mt8173 flash controller";
+	flash.write = nor_write;
+	flash.erase = nor_erase;
+	flash.read = nor_read;
+	flash.status = 0;
+	flash.sector_size = 0x1000;
+	flash.erase_cmd = SECTOR_ERASE_CMD;
+	flash.size = CONFIG_ROM_SIZE;
+	return &flash;
+}