From 9c7a6f8804aef7559ee8edcb7466676ee7d00c09 Mon Sep 17 00:00:00 2001
From: John Crispin <blogic@openwrt.org>
Date: Sat, 27 Aug 2011 20:08:14 +0200
Subject: [PATCH 41/70] MIPS: lantiq: add xway nand driver

This patch adds a nand driver for XWAY SoCs. The patch makes use of the
plat_nand driver. As with the EBU NOR driver merged in 3.0, we have the
endianess swap problem on read. To workaround this problem we make the
read_byte() callback available via the plat_nand driver causing the nand
layer to do byte reads.

Signed-off-by: John Crispin <blogic@openwrt.org>

TODO : memory ranges
       cs lines
       plat dev
       ebu2 and not ebu1 ?
---
 .../mips/include/asm/mach-lantiq/xway/lantiq_soc.h |    2 +
 arch/mips/lantiq/xway/Makefile                     |    2 +-
 arch/mips/lantiq/xway/devices.h                    |    1 +
 arch/mips/lantiq/xway/nand.c                       |  216 ++++++++++++++++++++
 drivers/mtd/nand/plat_nand.c                       |    1 +
 include/linux/mtd/nand.h                           |    1 +
 6 files changed, 222 insertions(+), 1 deletions(-)
 create mode 100644 arch/mips/lantiq/xway/nand.c

diff --git a/arch/mips/include/asm/mach-lantiq/xway/lantiq_soc.h b/arch/mips/include/asm/mach-lantiq/xway/lantiq_soc.h
index 3f22acb..ab2d236 100644
--- a/arch/mips/include/asm/mach-lantiq/xway/lantiq_soc.h
+++ b/arch/mips/include/asm/mach-lantiq/xway/lantiq_soc.h
@@ -145,6 +145,8 @@
 /* register access macros for EBU and CGU */
 #define ltq_ebu_w32(x, y)	ltq_w32((x), ltq_ebu_membase + (y))
 #define ltq_ebu_r32(x)		ltq_r32(ltq_ebu_membase + (x))
+#define ltq_ebu_w32_mask(x, y, z) \
+	ltq_w32_mask(x, y, ltq_ebu_membase + (z))
 #define ltq_cgu_w32(x, y)	ltq_w32((x), ltq_cgu_membase + (y))
 #define ltq_cgu_r32(x)		ltq_r32(ltq_cgu_membase + (x))
 
diff --git a/arch/mips/lantiq/xway/Makefile b/arch/mips/lantiq/xway/Makefile
index 9d1a0a2..277aa34 100644
--- a/arch/mips/lantiq/xway/Makefile
+++ b/arch/mips/lantiq/xway/Makefile
@@ -1,4 +1,4 @@
-obj-y := sysctrl.o reset.o gpio.o gpio_stp.o gpio_ebu.o devices.o dma.o clk.o prom.o
+obj-y := sysctrl.o reset.o gpio.o gpio_stp.o gpio_ebu.o devices.o dma.o clk.o prom.o nand.o
 
 obj-$(CONFIG_LANTIQ_MACH_EASY50712) += mach-easy50712.o
 obj-$(CONFIG_LANTIQ_MACH_EASY50601) += mach-easy50601.o
diff --git a/arch/mips/lantiq/xway/devices.h b/arch/mips/lantiq/xway/devices.h
index e904934..d825cbd 100644
--- a/arch/mips/lantiq/xway/devices.h
+++ b/arch/mips/lantiq/xway/devices.h
@@ -16,5 +16,6 @@ extern void ltq_register_gpio(void);
 extern void ltq_register_gpio_stp(void);
 extern void ltq_register_ase_asc(void);
 extern void ltq_register_etop(struct ltq_eth_data *eth);
+extern void xway_register_nand(struct mtd_partition *parts, int count);
 
 #endif
diff --git a/arch/mips/lantiq/xway/nand.c b/arch/mips/lantiq/xway/nand.c
new file mode 100644
index 0000000..9ab91d8
--- /dev/null
+++ b/arch/mips/lantiq/xway/nand.c
@@ -0,0 +1,216 @@
+/*
+ *  This program is free software; you can redistribute it and/or modify it
+ *  under the terms of the GNU General Public License version 2 as published
+ *  by the Free Software Foundation.
+ *
+ *  Copyright (C) 2010 John Crispin <blogic@openwrt.org>
+ */
+
+#include <linux/mtd/physmap.h>
+#include <linux/mtd/nand.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+
+#include <lantiq_soc.h>
+#include <lantiq_irq.h>
+#include <lantiq_platform.h>
+
+#include "devices.h"
+
+/* nand registers */
+#define LTQ_EBU_NAND_WAIT	0xB4
+#define LTQ_EBU_NAND_ECC0	0xB8
+#define LTQ_EBU_NAND_ECC_AC	0xBC
+#define LTQ_EBU_NAND_CON	0xB0
+#define LTQ_EBU_ADDSEL1		0x24
+
+/* gpio definitions */
+#define PIN_ALE			13
+#define PIN_CLE			24
+#define PIN_CS1			23
+#define PIN_RDY			48  /* NFLASH_READY */
+#define PIN_RD			49  /* NFLASH_READ_N */
+
+#define NAND_CMD_ALE		(1 << 2)
+#define NAND_CMD_CLE		(1 << 3)
+#define NAND_CMD_CS		(1 << 4)
+#define NAND_WRITE_CMD_RESET	0xff
+#define NAND_WRITE_CMD		(NAND_CMD_CS | NAND_CMD_CLE)
+#define NAND_WRITE_ADDR		(NAND_CMD_CS | NAND_CMD_ALE)
+#define NAND_WRITE_DATA		(NAND_CMD_CS)
+#define NAND_READ_DATA		(NAND_CMD_CS)
+#define NAND_WAIT_WR_C		(1 << 3)
+#define NAND_WAIT_RD		(0x1)
+
+#define ADDSEL1_MASK(x)		(x << 4)
+#define ADDSEL1_REGEN		1
+#define BUSCON1_SETUP		(1 << 22)
+#define BUSCON1_BCGEN_RES	(0x3 << 12)
+#define BUSCON1_WAITWRC2	(2 << 8)
+#define BUSCON1_WAITRDC2	(2 << 6)
+#define BUSCON1_HOLDC1		(1 << 4)
+#define BUSCON1_RECOVC1		(1 << 2)
+#define BUSCON1_CMULT4		1
+#define NAND_CON_NANDM		1
+#define NAND_CON_CSMUX		(1 << 1)
+#define NAND_CON_CS_P		(1 << 4)
+#define NAND_CON_SE_P		(1 << 5)
+#define NAND_CON_WP_P		(1 << 6)
+#define NAND_CON_PRE_P		(1 << 7)
+#define NAND_CON_IN_CS0		0
+#define NAND_CON_OUT_CS0	0
+#define NAND_CON_IN_CS1		(1 << 8)
+#define NAND_CON_OUT_CS1	(1 << 10)
+#define NAND_CON_CE		(1 << 20)
+
+#define NAND_BASE_ADDRESS	(KSEG1 | 0x14000000)
+
+static const char *part_probes[] = { "cmdlinepart", NULL };
+
+static void xway_select_chip(struct mtd_info *mtd, int chip)
+{
+	switch (chip) {
+	case -1:
+		ltq_ebu_w32_mask(NAND_CON_CE, 0, LTQ_EBU_NAND_CON);
+		ltq_ebu_w32_mask(NAND_CON_NANDM, 0, LTQ_EBU_NAND_CON);
+		break;
+	case 0:
+		ltq_ebu_w32_mask(0, NAND_CON_NANDM, LTQ_EBU_NAND_CON);
+		ltq_ebu_w32_mask(0, NAND_CON_CE, LTQ_EBU_NAND_CON);
+		/* reset the nand chip */
+		while ((ltq_ebu_r32(LTQ_EBU_NAND_WAIT) & NAND_WAIT_WR_C) == 0)
+			;
+		ltq_w32(NAND_WRITE_CMD_RESET,
+			((u32 *) (NAND_BASE_ADDRESS | NAND_WRITE_CMD)));
+		break;
+	default:
+		BUG();
+	}
+}
+
+static void xway_cmd_ctrl(struct mtd_info *mtd, int data, unsigned int ctrl)
+{
+	struct nand_chip *this = mtd->priv;
+
+	if (ctrl & NAND_CTRL_CHANGE) {
+		if (ctrl & NAND_CLE)
+			this->IO_ADDR_W = (void __iomem *)
+					(NAND_BASE_ADDRESS | NAND_WRITE_CMD);
+		else if (ctrl & NAND_ALE)
+			this->IO_ADDR_W = (void __iomem *)
+					(NAND_BASE_ADDRESS | NAND_WRITE_ADDR);
+	}
+
+	if (data != NAND_CMD_NONE) {
+		*(volatile u8*) ((u32) this->IO_ADDR_W) = data;
+		while ((ltq_ebu_r32(LTQ_EBU_NAND_WAIT) & NAND_WAIT_WR_C) == 0)
+			;
+	}
+}
+
+static int xway_dev_ready(struct mtd_info *mtd)
+{
+	return ltq_ebu_r32(LTQ_EBU_NAND_WAIT) & NAND_WAIT_RD;
+}
+
+void nand_write(unsigned int addr, unsigned int val)
+{
+	ltq_w32(val, ((u32 *) (NAND_BASE_ADDRESS | addr)));
+	while ((ltq_ebu_r32(LTQ_EBU_NAND_WAIT) & NAND_WAIT_WR_C) == 0)
+		;
+}
+
+unsigned char xway_read_byte(struct mtd_info *mtd)
+{
+	return ltq_r8((void __iomem *)(NAND_BASE_ADDRESS | (NAND_READ_DATA)));
+}
+
+static void xway_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
+{
+	int i;
+
+	for (i = 0; i < len; i++)
+	{
+		unsigned char res8 =  ltq_r8((void __iomem *)(NAND_BASE_ADDRESS | (NAND_READ_DATA)));
+		buf[i] = res8;
+	}
+}
+
+static void xway_write_buf(struct mtd_info *mtd, const uint8_t *buf, int len)
+{
+	int i;
+
+	for (i = 0; i < len; i++)
+	{
+		ltq_w8(buf[i], ((u32*)(NAND_BASE_ADDRESS | (NAND_WRITE_DATA))));
+		while((ltq_ebu_r32(LTQ_EBU_NAND_WAIT) & NAND_WAIT_WR_C) == 0);
+	}
+}
+
+int xway_probe(struct platform_device *pdev)
+{
+	/* might need this later ?
+	ltq_gpio_request(PIN_CS1, 2, 1, "NAND_CS1");
+	*/
+	ltq_gpio_request(&pdev->dev, PIN_CLE, 2, 1, "NAND_CLE");
+	ltq_gpio_request(&pdev->dev, PIN_ALE, 2, 1, "NAND_ALE");
+	if (ltq_is_ar9() || ltq_is_vr9()) {
+		ltq_gpio_request(&pdev->dev, PIN_RDY, 2, 0, "NAND_BSY");
+		ltq_gpio_request(&pdev->dev, PIN_RD, 2, 1, "NAND_RD");
+	}
+
+	ltq_ebu_w32((NAND_BASE_ADDRESS & 0x1fffff00)
+		| ADDSEL1_MASK(3) | ADDSEL1_REGEN, LTQ_EBU_ADDSEL1);
+
+	ltq_ebu_w32(BUSCON1_SETUP | BUSCON1_BCGEN_RES | BUSCON1_WAITWRC2
+		| BUSCON1_WAITRDC2 | BUSCON1_HOLDC1 | BUSCON1_RECOVC1
+		| BUSCON1_CMULT4, LTQ_EBU_BUSCON1);
+
+	ltq_ebu_w32(NAND_CON_NANDM | NAND_CON_CSMUX | NAND_CON_CS_P
+		| NAND_CON_SE_P | NAND_CON_WP_P | NAND_CON_PRE_P
+		| NAND_CON_IN_CS0 | NAND_CON_OUT_CS0, LTQ_EBU_NAND_CON);
+
+	ltq_w32(NAND_WRITE_CMD_RESET,
+		((u32 *) (NAND_BASE_ADDRESS | NAND_WRITE_CMD)));
+	while ((ltq_ebu_r32(LTQ_EBU_NAND_WAIT) & NAND_WAIT_WR_C) == 0)
+		;
+
+	return 0;
+}
+
+static struct platform_nand_data falcon_flash_nand_data = {
+	.chip = {
+		.nr_chips		= 1,
+		.chip_delay		= 30,
+		.part_probe_types	= part_probes,
+	},
+	.ctrl = {
+		.probe		= xway_probe,
+		.cmd_ctrl	= xway_cmd_ctrl,
+		.dev_ready	= xway_dev_ready,
+		.select_chip	= xway_select_chip,
+		.read_byte	= xway_read_byte,
+		.read_buf	= xway_read_buf,
+		.write_buf	= xway_write_buf,
+	}
+};
+
+static struct resource ltq_nand_res =
+	MEM_RES("nand", 0x14000000, 0x7ffffff);
+
+static struct platform_device ltq_flash_nand = {
+	.name		= "gen_nand",
+	.id		= -1,
+	.num_resources	= 1,
+	.resource	= &ltq_nand_res,
+	.dev		= {
+		.platform_data = &falcon_flash_nand_data,
+	},
+};
+
+void __init xway_register_nand(struct mtd_partition *parts, int count)
+{
+	falcon_flash_nand_data.chip.partitions = parts;
+	falcon_flash_nand_data.chip.nr_partitions = count;
+	platform_device_register(&ltq_flash_nand);
+}
diff --git a/drivers/mtd/nand/plat_nand.c b/drivers/mtd/nand/plat_nand.c
index ea8e123..9040ba1 100644
--- a/drivers/mtd/nand/plat_nand.c
+++ b/drivers/mtd/nand/plat_nand.c
@@ -75,6 +75,7 @@ static int __devinit plat_nand_probe(struct platform_device *pdev)
 	data->chip.select_chip = pdata->ctrl.select_chip;
 	data->chip.write_buf = pdata->ctrl.write_buf;
 	data->chip.read_buf = pdata->ctrl.read_buf;
+	data->chip.read_byte = pdata->ctrl.read_byte;
 	data->chip.chip_delay = pdata->chip.chip_delay;
 	data->chip.options |= pdata->chip.options;
 	data->chip.bbt_options |= pdata->chip.bbt_options;
diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h
index 904131b..80e11b9 100644
--- a/include/linux/mtd/nand.h
+++ b/include/linux/mtd/nand.h
@@ -650,6 +650,7 @@ struct platform_nand_ctrl {
 	void (*cmd_ctrl)(struct mtd_info *mtd, int dat, unsigned int ctrl);
 	void (*write_buf)(struct mtd_info *mtd, const uint8_t *buf, int len);
 	void (*read_buf)(struct mtd_info *mtd, uint8_t *buf, int len);
+	unsigned char (*read_byte)(struct mtd_info *mtd);
 	void *priv;
 };
 
-- 
1.7.7.1

