From e2d5b4ba92289cb0fcc9db741d159ef5eb852d9f Mon Sep 17 00:00:00 2001
From: John Crispin <blogic@openwrt.org>
Date: Sat, 27 Aug 2011 20:08:14 +0200
Subject: [PATCH 16/24] MIPS: lantiq: adds 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/nand.c                       |  185 ++++++++++++++++++++
 drivers/mtd/nand/plat_nand.c                       |    1 +
 include/linux/mtd/nand.h                           |    1 +
 5 files changed, 190 insertions(+), 1 deletions(-)
 create mode 100644 arch/mips/lantiq/xway/nand.c

--- a/arch/mips/include/asm/mach-lantiq/xway/lantiq_soc.h
+++ b/arch/mips/include/asm/mach-lantiq/xway/lantiq_soc.h
@@ -138,6 +138,8 @@
 /* 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))
 
--- 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
+obj-y := sysctrl.o reset.o gpio.o gpio_stp.o gpio_ebu.o devices.o dma.o nand.o
 
 obj-$(CONFIG_SOC_XWAY) += clk-xway.o prom-xway.o
 obj-$(CONFIG_SOC_AMAZON_SE) += clk-ase.o prom-ase.o
--- /dev/null
+++ b/arch/mips/lantiq/xway/nand.c
@@ -0,0 +1,185 @@
+/*
+ *  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 <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
+ltq_nand_read_byte(struct mtd_info *mtd)
+{
+	return ltq_r8((void __iomem *)(NAND_BASE_ADDRESS | (NAND_READ_DATA)));
+}
+
+int xway_nand_probe(struct platform_device *pdev)
+{
+//	ltq_gpio_request(PIN_CS1, 1, 0, 1, "NAND_CS1");
+	ltq_gpio_request(PIN_CLE, 1, 0, 1, "NAND_CLE");
+	ltq_gpio_request(PIN_ALE, 1, 0, 1, "NAND_ALE");
+	if (ltq_is_ar9() || ltq_is_vr9()) {
+		ltq_gpio_request(PIN_RDY, 1, 0, 0, "NAND_BSY");
+		ltq_gpio_request(PIN_RD, 1, 0, 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_nand_probe,
+		.cmd_ctrl	= xway_cmd_ctrl,
+		.dev_ready	= xway_dev_ready,
+		.select_chip	= xway_select_chip,
+		.read_byte = ltq_nand_read_byte,
+	}
+};
+
+static struct resource ltq_nand_res =
+	MEM_RES("nand", 0x14000000, 0x3ffffff);
+
+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(void)
+{
+	platform_device_register(&ltq_flash_nand);
+}
--- a/drivers/mtd/nand/plat_nand.c
+++ b/drivers/mtd/nand/plat_nand.c
@@ -77,6 +77,7 @@ static int __devinit plat_nand_probe(str
 	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;
 
--- a/include/linux/mtd/nand.h
+++ b/include/linux/mtd/nand.h
@@ -657,6 +657,7 @@ 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;
 };