1 files changed, 920 insertions, 0 deletions

diff --git a/arch/arm/mach-omap2/gpmc.c b/arch/arm/mach-omap2/gpmc.c
new file mode 100644
index 00000000..dfffbbf4
--- /dev/null
+++ b/arch/arm/mach-omap2/gpmc.c
@@ -0,0 +1,920 @@
+/*
+ * GPMC support functions
+ *
+ * Copyright (C) 2005-2006 Nokia Corporation
+ *
+ * Author: Juha Yrjola
+ *
+ * Copyright (C) 2009 Texas Instruments
+ * Added OMAP4 support - Santosh Shilimkar <santosh.shilimkar@ti.com>
+ *
+ * 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.
+ */
+#undef DEBUG
+
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+#include <linux/ioport.h>
+#include <linux/spinlock.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+
+#include <asm/mach-types.h>
+#include <plat/gpmc.h>
+
+#include <plat/sdrc.h>
+
+/* GPMC register offsets */
+#define GPMC_REVISION		0x00
+#define GPMC_SYSCONFIG		0x10
+#define GPMC_SYSSTATUS		0x14
+#define GPMC_IRQSTATUS		0x18
+#define GPMC_IRQENABLE		0x1c
+#define GPMC_TIMEOUT_CONTROL	0x40
+#define GPMC_ERR_ADDRESS	0x44
+#define GPMC_ERR_TYPE		0x48
+#define GPMC_CONFIG		0x50
+#define GPMC_STATUS		0x54
+#define GPMC_PREFETCH_CONFIG1	0x1e0
+#define GPMC_PREFETCH_CONFIG2	0x1e4
+#define GPMC_PREFETCH_CONTROL	0x1ec
+#define GPMC_PREFETCH_STATUS	0x1f0
+#define GPMC_ECC_CONFIG		0x1f4
+#define GPMC_ECC_CONTROL	0x1f8
+#define GPMC_ECC_SIZE_CONFIG	0x1fc
+#define GPMC_ECC1_RESULT        0x200
+
+#define GPMC_CS0_OFFSET		0x60
+#define GPMC_CS_SIZE		0x30
+
+#define GPMC_MEM_START		0x00000000
+#define GPMC_MEM_END		0x3FFFFFFF
+#define BOOT_ROM_SPACE		0x100000	/* 1MB */
+
+#define GPMC_CHUNK_SHIFT	24		/* 16 MB */
+#define GPMC_SECTION_SHIFT	28		/* 128 MB */
+
+#define CS_NUM_SHIFT		24
+#define ENABLE_PREFETCH		(0x1 << 7)
+#define DMA_MPU_MODE		2
+
+/* Structure to save gpmc cs context */
+struct gpmc_cs_config {
+	u32 config1;
+	u32 config2;
+	u32 config3;
+	u32 config4;
+	u32 config5;
+	u32 config6;
+	u32 config7;
+	int is_valid;
+};
+
+/*
+ * Structure to save/restore gpmc context
+ * to support core off on OMAP3
+ */
+struct omap3_gpmc_regs {
+	u32 sysconfig;
+	u32 irqenable;
+	u32 timeout_ctrl;
+	u32 config;
+	u32 prefetch_config1;
+	u32 prefetch_config2;
+	u32 prefetch_control;
+	struct gpmc_cs_config cs_context[GPMC_CS_NUM];
+};
+
+static struct resource	gpmc_mem_root;
+static struct resource	gpmc_cs_mem[GPMC_CS_NUM];
+static DEFINE_SPINLOCK(gpmc_mem_lock);
+static unsigned int gpmc_cs_map;	/* flag for cs which are initialized */
+static int gpmc_ecc_used = -EINVAL;	/* cs using ecc engine */
+
+static void __iomem *gpmc_base;
+
+static struct clk *gpmc_l3_clk;
+
+static irqreturn_t gpmc_handle_irq(int irq, void *dev);
+
+static void gpmc_write_reg(int idx, u32 val)
+{
+	__raw_writel(val, gpmc_base + idx);
+}
+
+static u32 gpmc_read_reg(int idx)
+{
+	return __raw_readl(gpmc_base + idx);
+}
+
+static void gpmc_cs_write_byte(int cs, int idx, u8 val)
+{
+	void __iomem *reg_addr;
+
+	reg_addr = gpmc_base + GPMC_CS0_OFFSET + (cs * GPMC_CS_SIZE) + idx;
+	__raw_writeb(val, reg_addr);
+}
+
+static u8 gpmc_cs_read_byte(int cs, int idx)
+{
+	void __iomem *reg_addr;
+
+	reg_addr = gpmc_base + GPMC_CS0_OFFSET + (cs * GPMC_CS_SIZE) + idx;
+	return __raw_readb(reg_addr);
+}
+
+void gpmc_cs_write_reg(int cs, int idx, u32 val)
+{
+	void __iomem *reg_addr;
+
+	reg_addr = gpmc_base + GPMC_CS0_OFFSET + (cs * GPMC_CS_SIZE) + idx;
+	__raw_writel(val, reg_addr);
+}
+
+u32 gpmc_cs_read_reg(int cs, int idx)
+{
+	void __iomem *reg_addr;
+
+	reg_addr = gpmc_base + GPMC_CS0_OFFSET + (cs * GPMC_CS_SIZE) + idx;
+	return __raw_readl(reg_addr);
+}
+
+/* TODO: Add support for gpmc_fck to clock framework and use it */
+unsigned long gpmc_get_fclk_period(void)
+{
+	unsigned long rate = clk_get_rate(gpmc_l3_clk);
+
+	if (rate == 0) {
+		printk(KERN_WARNING "gpmc_l3_clk not enabled\n");
+		return 0;
+	}
+
+	rate /= 1000;
+	rate = 1000000000 / rate;	/* In picoseconds */
+
+	return rate;
+}
+
+unsigned int gpmc_ns_to_ticks(unsigned int time_ns)
+{
+	unsigned long tick_ps;
+
+	/* Calculate in picosecs to yield more exact results */
+	tick_ps = gpmc_get_fclk_period();
+
+	return (time_ns * 1000 + tick_ps - 1) / tick_ps;
+}
+
+unsigned int gpmc_ps_to_ticks(unsigned int time_ps)
+{
+	unsigned long tick_ps;
+
+	/* Calculate in picosecs to yield more exact results */
+	tick_ps = gpmc_get_fclk_period();
+
+	return (time_ps + tick_ps - 1) / tick_ps;
+}
+
+unsigned int gpmc_ticks_to_ns(unsigned int ticks)
+{
+	return ticks * gpmc_get_fclk_period() / 1000;
+}
+
+unsigned int gpmc_round_ns_to_ticks(unsigned int time_ns)
+{
+	unsigned long ticks = gpmc_ns_to_ticks(time_ns);
+
+	return ticks * gpmc_get_fclk_period() / 1000;
+}
+
+#ifdef DEBUG
+static int set_gpmc_timing_reg(int cs, int reg, int st_bit, int end_bit,
+			       int time, const char *name)
+#else
+static int set_gpmc_timing_reg(int cs, int reg, int st_bit, int end_bit,
+			       int time)
+#endif
+{
+	u32 l;
+	int ticks, mask, nr_bits;
+
+	if (time == 0)
+		ticks = 0;
+	else
+		ticks = gpmc_ns_to_ticks(time);
+	nr_bits = end_bit - st_bit + 1;
+	if (ticks >= 1 << nr_bits) {
+#ifdef DEBUG
+		printk(KERN_INFO "GPMC CS%d: %-10s* %3d ns, %3d ticks >= %d\n",
+				cs, name, time, ticks, 1 << nr_bits);
+#endif
+		return -1;
+	}
+
+	mask = (1 << nr_bits) - 1;
+	l = gpmc_cs_read_reg(cs, reg);
+#ifdef DEBUG
+	printk(KERN_INFO
+		"GPMC CS%d: %-10s: %3d ticks, %3lu ns (was %3i ticks) %3d ns\n",
+	       cs, name, ticks, gpmc_get_fclk_period() * ticks / 1000,
+			(l >> st_bit) & mask, time);
+#endif
+	l &= ~(mask << st_bit);
+	l |= ticks << st_bit;
+	gpmc_cs_write_reg(cs, reg, l);
+
+	return 0;
+}
+
+#ifdef DEBUG
+#define GPMC_SET_ONE(reg, st, end, field) \
+	if (set_gpmc_timing_reg(cs, (reg), (st), (end),		\
+			t->field, #field) < 0)			\
+		return -1
+#else
+#define GPMC_SET_ONE(reg, st, end, field) \
+	if (set_gpmc_timing_reg(cs, (reg), (st), (end), t->field) < 0) \
+		return -1
+#endif
+
+int gpmc_cs_calc_divider(int cs, unsigned int sync_clk)
+{
+	int div;
+	u32 l;
+
+	l = sync_clk + (gpmc_get_fclk_period() - 1);
+	div = l / gpmc_get_fclk_period();
+	if (div > 4)
+		return -1;
+	if (div <= 0)
+		div = 1;
+
+	return div;
+}
+
+int gpmc_cs_set_timings(int cs, const struct gpmc_timings *t)
+{
+	int div;
+	u32 l;
+
+	div = gpmc_cs_calc_divider(cs, t->sync_clk);
+	if (div < 0)
+		return -1;
+
+	GPMC_SET_ONE(GPMC_CS_CONFIG2,  0,  3, cs_on);
+	GPMC_SET_ONE(GPMC_CS_CONFIG2,  8, 12, cs_rd_off);
+	GPMC_SET_ONE(GPMC_CS_CONFIG2, 16, 20, cs_wr_off);
+
+	GPMC_SET_ONE(GPMC_CS_CONFIG3,  0,  3, adv_on);
+	GPMC_SET_ONE(GPMC_CS_CONFIG3,  8, 12, adv_rd_off);
+	GPMC_SET_ONE(GPMC_CS_CONFIG3, 16, 20, adv_wr_off);
+
+	GPMC_SET_ONE(GPMC_CS_CONFIG4,  0,  3, oe_on);
+	GPMC_SET_ONE(GPMC_CS_CONFIG4,  8, 12, oe_off);
+	GPMC_SET_ONE(GPMC_CS_CONFIG4, 16, 19, we_on);
+	GPMC_SET_ONE(GPMC_CS_CONFIG4, 24, 28, we_off);
+
+	GPMC_SET_ONE(GPMC_CS_CONFIG5,  0,  4, rd_cycle);
+	GPMC_SET_ONE(GPMC_CS_CONFIG5,  8, 12, wr_cycle);
+	GPMC_SET_ONE(GPMC_CS_CONFIG5, 16, 20, access);
+
+	GPMC_SET_ONE(GPMC_CS_CONFIG5, 24, 27, page_burst_access);
+
+	if (cpu_is_omap34xx()) {
+		GPMC_SET_ONE(GPMC_CS_CONFIG6, 16, 19, wr_data_mux_bus);
+		GPMC_SET_ONE(GPMC_CS_CONFIG6, 24, 28, wr_access);
+	}
+
+	/* caller is expected to have initialized CONFIG1 to cover
+	 * at least sync vs async
+	 */
+	l = gpmc_cs_read_reg(cs, GPMC_CS_CONFIG1);
+	if (l & (GPMC_CONFIG1_READTYPE_SYNC | GPMC_CONFIG1_WRITETYPE_SYNC)) {
+#ifdef DEBUG
+		printk(KERN_INFO "GPMC CS%d CLK period is %lu ns (div %d)\n",
+				cs, (div * gpmc_get_fclk_period()) / 1000, div);
+#endif
+		l &= ~0x03;
+		l |= (div - 1);
+		gpmc_cs_write_reg(cs, GPMC_CS_CONFIG1, l);
+	}
+
+	return 0;
+}
+
+static void gpmc_cs_enable_mem(int cs, u32 base, u32 size)
+{
+	u32 l;
+	u32 mask;
+
+	mask = (1 << GPMC_SECTION_SHIFT) - size;
+	l = gpmc_cs_read_reg(cs, GPMC_CS_CONFIG7);
+	l &= ~0x3f;
+	l = (base >> GPMC_CHUNK_SHIFT) & 0x3f;
+	l &= ~(0x0f << 8);
+	l |= ((mask >> GPMC_CHUNK_SHIFT) & 0x0f) << 8;
+	l |= GPMC_CONFIG7_CSVALID;
+	gpmc_cs_write_reg(cs, GPMC_CS_CONFIG7, l);
+}
+
+static void gpmc_cs_disable_mem(int cs)
+{
+	u32 l;
+
+	l = gpmc_cs_read_reg(cs, GPMC_CS_CONFIG7);
+	l &= ~GPMC_CONFIG7_CSVALID;
+	gpmc_cs_write_reg(cs, GPMC_CS_CONFIG7, l);
+}
+
+static void gpmc_cs_get_memconf(int cs, u32 *base, u32 *size)
+{
+	u32 l;
+	u32 mask;
+
+	l = gpmc_cs_read_reg(cs, GPMC_CS_CONFIG7);
+	*base = (l & 0x3f) << GPMC_CHUNK_SHIFT;
+	mask = (l >> 8) & 0x0f;
+	*size = (1 << GPMC_SECTION_SHIFT) - (mask << GPMC_CHUNK_SHIFT);
+}
+
+static int gpmc_cs_mem_enabled(int cs)
+{
+	u32 l;
+
+	l = gpmc_cs_read_reg(cs, GPMC_CS_CONFIG7);
+	return l & GPMC_CONFIG7_CSVALID;
+}
+
+int gpmc_cs_set_reserved(int cs, int reserved)
+{
+	if (cs > GPMC_CS_NUM)
+		return -ENODEV;
+
+	gpmc_cs_map &= ~(1 << cs);
+	gpmc_cs_map |= (reserved ? 1 : 0) << cs;
+
+	return 0;
+}
+
+int gpmc_cs_reserved(int cs)
+{
+	if (cs > GPMC_CS_NUM)
+		return -ENODEV;
+
+	return gpmc_cs_map & (1 << cs);
+}
+
+static unsigned long gpmc_mem_align(unsigned long size)
+{
+	int order;
+
+	size = (size - 1) >> (GPMC_CHUNK_SHIFT - 1);
+	order = GPMC_CHUNK_SHIFT - 1;
+	do {
+		size >>= 1;
+		order++;
+	} while (size);
+	size = 1 << order;
+	return size;
+}
+
+static int gpmc_cs_insert_mem(int cs, unsigned long base, unsigned long size)
+{
+	struct resource	*res = &gpmc_cs_mem[cs];
+	int r;
+
+	size = gpmc_mem_align(size);
+	spin_lock(&gpmc_mem_lock);
+	res->start = base;
+	res->end = base + size - 1;
+	r = request_resource(&gpmc_mem_root, res);
+	spin_unlock(&gpmc_mem_lock);
+
+	return r;
+}
+
+int gpmc_cs_request(int cs, unsigned long size, unsigned long *base)
+{
+	struct resource *res = &gpmc_cs_mem[cs];
+	int r = -1;
+
+	if (cs > GPMC_CS_NUM)
+		return -ENODEV;
+
+	size = gpmc_mem_align(size);
+	if (size > (1 << GPMC_SECTION_SHIFT))
+		return -ENOMEM;
+
+	spin_lock(&gpmc_mem_lock);
+	if (gpmc_cs_reserved(cs)) {
+		r = -EBUSY;
+		goto out;
+	}
+	if (gpmc_cs_mem_enabled(cs))
+		r = adjust_resource(res, res->start & ~(size - 1), size);
+	if (r < 0)
+		r = allocate_resource(&gpmc_mem_root, res, size, 0, ~0,
+				      size, NULL, NULL);
+	if (r < 0)
+		goto out;
+
+	gpmc_cs_enable_mem(cs, res->start, resource_size(res));
+	*base = res->start;
+	gpmc_cs_set_reserved(cs, 1);
+out:
+	spin_unlock(&gpmc_mem_lock);
+	return r;
+}
+EXPORT_SYMBOL(gpmc_cs_request);
+
+void gpmc_cs_free(int cs)
+{
+	spin_lock(&gpmc_mem_lock);
+	if (cs >= GPMC_CS_NUM || cs < 0 || !gpmc_cs_reserved(cs)) {
+		printk(KERN_ERR "Trying to free non-reserved GPMC CS%d\n", cs);
+		BUG();
+		spin_unlock(&gpmc_mem_lock);
+		return;
+	}
+	gpmc_cs_disable_mem(cs);
+	release_resource(&gpmc_cs_mem[cs]);
+	gpmc_cs_set_reserved(cs, 0);
+	spin_unlock(&gpmc_mem_lock);
+}
+EXPORT_SYMBOL(gpmc_cs_free);
+
+/**
+ * gpmc_read_status - read access request to get the different gpmc status
+ * @cmd: command type
+ * @return status
+ */
+int gpmc_read_status(int cmd)
+{
+	int	status = -EINVAL;
+	u32	regval = 0;
+
+	switch (cmd) {
+	case GPMC_GET_IRQ_STATUS:
+		status = gpmc_read_reg(GPMC_IRQSTATUS);
+		break;
+
+	case GPMC_PREFETCH_FIFO_CNT:
+		regval = gpmc_read_reg(GPMC_PREFETCH_STATUS);
+		status = GPMC_PREFETCH_STATUS_FIFO_CNT(regval);
+		break;
+
+	case GPMC_PREFETCH_COUNT:
+		regval = gpmc_read_reg(GPMC_PREFETCH_STATUS);
+		status = GPMC_PREFETCH_STATUS_COUNT(regval);
+		break;
+
+	case GPMC_STATUS_BUFFER:
+		regval = gpmc_read_reg(GPMC_STATUS);
+		/* 1 : buffer is available to write */
+		status = regval & GPMC_STATUS_BUFF_EMPTY;
+		break;
+
+	default:
+		printk(KERN_ERR "gpmc_read_status: Not supported\n");
+	}
+	return status;
+}
+EXPORT_SYMBOL(gpmc_read_status);
+
+/**
+ * gpmc_cs_configure - write request to configure gpmc
+ * @cs: chip select number
+ * @cmd: command type
+ * @wval: value to write
+ * @return status of the operation
+ */
+int gpmc_cs_configure(int cs, int cmd, int wval)
+{
+	int err = 0;
+	u32 regval = 0;
+
+	switch (cmd) {
+	case GPMC_ENABLE_IRQ:
+		gpmc_write_reg(GPMC_IRQENABLE, wval);
+		break;
+
+	case GPMC_SET_IRQ_STATUS:
+		gpmc_write_reg(GPMC_IRQSTATUS, wval);
+		break;
+
+	case GPMC_CONFIG_WP:
+		regval = gpmc_read_reg(GPMC_CONFIG);
+		if (wval)
+			regval &= ~GPMC_CONFIG_WRITEPROTECT; /* WP is ON */
+		else
+			regval |= GPMC_CONFIG_WRITEPROTECT;  /* WP is OFF */
+		gpmc_write_reg(GPMC_CONFIG, regval);
+		break;
+
+	case GPMC_CONFIG_RDY_BSY:
+		regval  = gpmc_cs_read_reg(cs, GPMC_CS_CONFIG1);
+		if (wval)
+			regval |= WR_RD_PIN_MONITORING;
+		else
+			regval &= ~WR_RD_PIN_MONITORING;
+		gpmc_cs_write_reg(cs, GPMC_CS_CONFIG1, regval);
+		break;
+
+	case GPMC_CONFIG_DEV_SIZE:
+		regval  = gpmc_cs_read_reg(cs, GPMC_CS_CONFIG1);
+
+		/* clear 2 target bits */
+		regval &= ~GPMC_CONFIG1_DEVICESIZE(3);
+
+		/* set the proper value */
+		regval |= GPMC_CONFIG1_DEVICESIZE(wval);
+
+		gpmc_cs_write_reg(cs, GPMC_CS_CONFIG1, regval);
+		break;
+
+	case GPMC_CONFIG_DEV_TYPE:
+		regval  = gpmc_cs_read_reg(cs, GPMC_CS_CONFIG1);
+		regval |= GPMC_CONFIG1_DEVICETYPE(wval);
+		if (wval == GPMC_DEVICETYPE_NOR)
+			regval |= GPMC_CONFIG1_MUXADDDATA;
+		gpmc_cs_write_reg(cs, GPMC_CS_CONFIG1, regval);
+		break;
+
+	default:
+		printk(KERN_ERR "gpmc_configure_cs: Not supported\n");
+		err = -EINVAL;
+	}
+
+	return err;
+}
+EXPORT_SYMBOL(gpmc_cs_configure);
+
+/**
+ * gpmc_nand_read - nand specific read access request
+ * @cs: chip select number
+ * @cmd: command type
+ */
+int gpmc_nand_read(int cs, int cmd)
+{
+	int rval = -EINVAL;
+
+	switch (cmd) {
+	case GPMC_NAND_DATA:
+		rval = gpmc_cs_read_byte(cs, GPMC_CS_NAND_DATA);
+		break;
+
+	default:
+		printk(KERN_ERR "gpmc_read_nand_ctrl: Not supported\n");
+	}
+	return rval;
+}
+EXPORT_SYMBOL(gpmc_nand_read);
+
+/**
+ * gpmc_nand_write - nand specific write request
+ * @cs: chip select number
+ * @cmd: command type
+ * @wval: value to write
+ */
+int gpmc_nand_write(int cs, int cmd, int wval)
+{
+	int err = 0;
+
+	switch (cmd) {
+	case GPMC_NAND_COMMAND:
+		gpmc_cs_write_byte(cs, GPMC_CS_NAND_COMMAND, wval);
+		break;
+
+	case GPMC_NAND_ADDRESS:
+		gpmc_cs_write_byte(cs, GPMC_CS_NAND_ADDRESS, wval);
+		break;
+
+	case GPMC_NAND_DATA:
+		gpmc_cs_write_byte(cs, GPMC_CS_NAND_DATA, wval);
+
+	default:
+		printk(KERN_ERR "gpmc_write_nand_ctrl: Not supported\n");
+		err = -EINVAL;
+	}
+	return err;
+}
+EXPORT_SYMBOL(gpmc_nand_write);
+
+
+
+/**
+ * gpmc_prefetch_enable - configures and starts prefetch transfer
+ * @cs: cs (chip select) number
+ * @fifo_th: fifo threshold to be used for read/ write
+ * @dma_mode: dma mode enable (1) or disable (0)
+ * @u32_count: number of bytes to be transferred
+ * @is_write: prefetch read(0) or write post(1) mode
+ */
+int gpmc_prefetch_enable(int cs, int fifo_th, int dma_mode,
+				unsigned int u32_count, int is_write)
+{
+
+	if (fifo_th > PREFETCH_FIFOTHRESHOLD_MAX) {
+		pr_err("gpmc: fifo threshold is not supported\n");
+		return -1;
+	} else if (!(gpmc_read_reg(GPMC_PREFETCH_CONTROL))) {
+		/* Set the amount of bytes to be prefetched */
+		gpmc_write_reg(GPMC_PREFETCH_CONFIG2, u32_count);
+
+		/* Set dma/mpu mode, the prefetch read / post write and
+		 * enable the engine. Set which cs is has requested for.
+		 */
+		gpmc_write_reg(GPMC_PREFETCH_CONFIG1, ((cs << CS_NUM_SHIFT) |
+					PREFETCH_FIFOTHRESHOLD(fifo_th) |
+					ENABLE_PREFETCH |
+					(dma_mode << DMA_MPU_MODE) |
+					(0x1 & is_write)));
+
+		/*  Start the prefetch engine */
+		gpmc_write_reg(GPMC_PREFETCH_CONTROL, 0x1);
+	} else {
+		return -EBUSY;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(gpmc_prefetch_enable);
+
+/**
+ * gpmc_prefetch_reset - disables and stops the prefetch engine
+ */
+int gpmc_prefetch_reset(int cs)
+{
+	u32 config1;
+
+	/* check if the same module/cs is trying to reset */
+	config1 = gpmc_read_reg(GPMC_PREFETCH_CONFIG1);
+	if (((config1 >> CS_NUM_SHIFT) & 0x7) != cs)
+		return -EINVAL;
+
+	/* Stop the PFPW engine */
+	gpmc_write_reg(GPMC_PREFETCH_CONTROL, 0x0);
+
+	/* Reset/disable the PFPW engine */
+	gpmc_write_reg(GPMC_PREFETCH_CONFIG1, 0x0);
+
+	return 0;
+}
+EXPORT_SYMBOL(gpmc_prefetch_reset);
+
+static void __init gpmc_mem_init(void)
+{
+	int cs;
+	unsigned long boot_rom_space = 0;
+
+	/* never allocate the first page, to facilitate bug detection;
+	 * even if we didn't boot from ROM.
+	 */
+	boot_rom_space = BOOT_ROM_SPACE;
+	/* In apollon the CS0 is mapped as 0x0000 0000 */
+	if (machine_is_omap_apollon())
+		boot_rom_space = 0;
+	gpmc_mem_root.start = GPMC_MEM_START + boot_rom_space;
+	gpmc_mem_root.end = GPMC_MEM_END;
+
+	/* Reserve all regions that has been set up by bootloader */
+	for (cs = 0; cs < GPMC_CS_NUM; cs++) {
+		u32 base, size;
+
+		if (!gpmc_cs_mem_enabled(cs))
+			continue;
+		gpmc_cs_get_memconf(cs, &base, &size);
+		if (gpmc_cs_insert_mem(cs, base, size) < 0)
+			BUG();
+	}
+}
+
+static int __init gpmc_init(void)
+{
+	u32 l, irq;
+	int cs, ret = -EINVAL;
+	int gpmc_irq;
+	char *ck = NULL;
+
+	if (cpu_is_omap24xx()) {
+		ck = "core_l3_ck";
+		if (cpu_is_omap2420())
+			l = OMAP2420_GPMC_BASE;
+		else
+			l = OMAP34XX_GPMC_BASE;
+		gpmc_irq = INT_34XX_GPMC_IRQ;
+	} else if (cpu_is_omap34xx()) {
+		ck = "gpmc_fck";
+		l = OMAP34XX_GPMC_BASE;
+		gpmc_irq = INT_34XX_GPMC_IRQ;
+	} else if (cpu_is_omap44xx()) {
+		ck = "gpmc_ck";
+		l = OMAP44XX_GPMC_BASE;
+		gpmc_irq = OMAP44XX_IRQ_GPMC;
+	}
+
+	if (WARN_ON(!ck))
+		return ret;
+
+	gpmc_l3_clk = clk_get(NULL, ck);
+	if (IS_ERR(gpmc_l3_clk)) {
+		printk(KERN_ERR "Could not get GPMC clock %s\n", ck);
+		BUG();
+	}
+
+	gpmc_base = ioremap(l, SZ_4K);
+	if (!gpmc_base) {
+		clk_put(gpmc_l3_clk);
+		printk(KERN_ERR "Could not get GPMC register memory\n");
+		BUG();
+	}
+
+	clk_enable(gpmc_l3_clk);
+
+	l = gpmc_read_reg(GPMC_REVISION);
+	printk(KERN_INFO "GPMC revision %d.%d\n", (l >> 4) & 0x0f, l & 0x0f);
+	/* Set smart idle mode and automatic L3 clock gating */
+	l = gpmc_read_reg(GPMC_SYSCONFIG);
+	l &= 0x03 << 3;
+	l |= (0x02 << 3) | (1 << 0);
+	gpmc_write_reg(GPMC_SYSCONFIG, l);
+	gpmc_mem_init();
+
+	/* initalize the irq_chained */
+	irq = OMAP_GPMC_IRQ_BASE;
+	for (cs = 0; cs < GPMC_CS_NUM; cs++) {
+		irq_set_chip_and_handler(irq, &dummy_irq_chip,
+						handle_simple_irq);
+		set_irq_flags(irq, IRQF_VALID);
+		irq++;
+	}
+
+	ret = request_irq(gpmc_irq,
+			gpmc_handle_irq, IRQF_SHARED, "gpmc", gpmc_base);
+	if (ret)
+		pr_err("gpmc: irq-%d could not claim: err %d\n",
+						gpmc_irq, ret);
+	return ret;
+}
+postcore_initcall(gpmc_init);
+
+static irqreturn_t gpmc_handle_irq(int irq, void *dev)
+{
+	u8 cs;
+
+	/* check cs to invoke the irq */
+	cs = ((gpmc_read_reg(GPMC_PREFETCH_CONFIG1)) >> CS_NUM_SHIFT) & 0x7;
+	if (OMAP_GPMC_IRQ_BASE+cs <= OMAP_GPMC_IRQ_END)
+		generic_handle_irq(OMAP_GPMC_IRQ_BASE+cs);
+
+	return IRQ_HANDLED;
+}
+
+#ifdef CONFIG_ARCH_OMAP3
+static struct omap3_gpmc_regs gpmc_context;
+
+void omap3_gpmc_save_context(void)
+{
+	int i;
+
+	gpmc_context.sysconfig = gpmc_read_reg(GPMC_SYSCONFIG);
+	gpmc_context.irqenable = gpmc_read_reg(GPMC_IRQENABLE);
+	gpmc_context.timeout_ctrl = gpmc_read_reg(GPMC_TIMEOUT_CONTROL);
+	gpmc_context.config = gpmc_read_reg(GPMC_CONFIG);
+	gpmc_context.prefetch_config1 = gpmc_read_reg(GPMC_PREFETCH_CONFIG1);
+	gpmc_context.prefetch_config2 = gpmc_read_reg(GPMC_PREFETCH_CONFIG2);
+	gpmc_context.prefetch_control = gpmc_read_reg(GPMC_PREFETCH_CONTROL);
+	for (i = 0; i < GPMC_CS_NUM; i++) {
+		gpmc_context.cs_context[i].is_valid = gpmc_cs_mem_enabled(i);
+		if (gpmc_context.cs_context[i].is_valid) {
+			gpmc_context.cs_context[i].config1 =
+				gpmc_cs_read_reg(i, GPMC_CS_CONFIG1);
+			gpmc_context.cs_context[i].config2 =
+				gpmc_cs_read_reg(i, GPMC_CS_CONFIG2);
+			gpmc_context.cs_context[i].config3 =
+				gpmc_cs_read_reg(i, GPMC_CS_CONFIG3);
+			gpmc_context.cs_context[i].config4 =
+				gpmc_cs_read_reg(i, GPMC_CS_CONFIG4);
+			gpmc_context.cs_context[i].config5 =
+				gpmc_cs_read_reg(i, GPMC_CS_CONFIG5);
+			gpmc_context.cs_context[i].config6 =
+				gpmc_cs_read_reg(i, GPMC_CS_CONFIG6);
+			gpmc_context.cs_context[i].config7 =
+				gpmc_cs_read_reg(i, GPMC_CS_CONFIG7);
+		}
+	}
+}
+
+void omap3_gpmc_restore_context(void)
+{
+	int i;
+
+	gpmc_write_reg(GPMC_SYSCONFIG, gpmc_context.sysconfig);
+	gpmc_write_reg(GPMC_IRQENABLE, gpmc_context.irqenable);
+	gpmc_write_reg(GPMC_TIMEOUT_CONTROL, gpmc_context.timeout_ctrl);
+	gpmc_write_reg(GPMC_CONFIG, gpmc_context.config);
+	gpmc_write_reg(GPMC_PREFETCH_CONFIG1, gpmc_context.prefetch_config1);
+	gpmc_write_reg(GPMC_PREFETCH_CONFIG2, gpmc_context.prefetch_config2);
+	gpmc_write_reg(GPMC_PREFETCH_CONTROL, gpmc_context.prefetch_control);
+	for (i = 0; i < GPMC_CS_NUM; i++) {
+		if (gpmc_context.cs_context[i].is_valid) {
+			gpmc_cs_write_reg(i, GPMC_CS_CONFIG1,
+				gpmc_context.cs_context[i].config1);
+			gpmc_cs_write_reg(i, GPMC_CS_CONFIG2,
+				gpmc_context.cs_context[i].config2);
+			gpmc_cs_write_reg(i, GPMC_CS_CONFIG3,
+				gpmc_context.cs_context[i].config3);
+			gpmc_cs_write_reg(i, GPMC_CS_CONFIG4,
+				gpmc_context.cs_context[i].config4);
+			gpmc_cs_write_reg(i, GPMC_CS_CONFIG5,
+				gpmc_context.cs_context[i].config5);
+			gpmc_cs_write_reg(i, GPMC_CS_CONFIG6,
+				gpmc_context.cs_context[i].config6);
+			gpmc_cs_write_reg(i, GPMC_CS_CONFIG7,
+				gpmc_context.cs_context[i].config7);
+		}
+	}
+}
+#endif /* CONFIG_ARCH_OMAP3 */
+
+/**
+ * gpmc_enable_hwecc - enable hardware ecc functionality
+ * @cs: chip select number
+ * @mode: read/write mode
+ * @dev_width: device bus width(1 for x16, 0 for x8)
+ * @ecc_size: bytes for which ECC will be generated
+ */
+int gpmc_enable_hwecc(int cs, int mode, int dev_width, int ecc_size)
+{
+	unsigned int val;
+
+	/* check if ecc module is in used */
+	if (gpmc_ecc_used != -EINVAL)
+		return -EINVAL;
+
+	gpmc_ecc_used = cs;
+
+	/* clear ecc and enable bits */
+	val = ((0x00000001<<8) | 0x00000001);
+	gpmc_write_reg(GPMC_ECC_CONTROL, val);
+
+	/* program ecc and result sizes */
+	val = ((((ecc_size >> 1) - 1) << 22) | (0x0000000F));
+	gpmc_write_reg(GPMC_ECC_SIZE_CONFIG, val);
+
+	switch (mode) {
+	case GPMC_ECC_READ:
+		gpmc_write_reg(GPMC_ECC_CONTROL, 0x101);
+		break;
+	case GPMC_ECC_READSYN:
+		 gpmc_write_reg(GPMC_ECC_CONTROL, 0x100);
+		break;
+	case GPMC_ECC_WRITE:
+		gpmc_write_reg(GPMC_ECC_CONTROL, 0x101);
+		break;
+	default:
+		printk(KERN_INFO "Error: Unrecognized Mode[%d]!\n", mode);
+		break;
+	}
+
+	/* (ECC 16 or 8 bit col) | ( CS  )  | ECC Enable */
+	val = (dev_width << 7) | (cs << 1) | (0x1);
+	gpmc_write_reg(GPMC_ECC_CONFIG, val);
+	return 0;
+}
+
+/**
+ * gpmc_calculate_ecc - generate non-inverted ecc bytes
+ * @cs: chip select number
+ * @dat: data pointer over which ecc is computed
+ * @ecc_code: ecc code buffer
+ *
+ * Using non-inverted ECC is considered ugly since writing a blank
+ * page (padding) will clear the ECC bytes. This is not a problem as long
+ * no one is trying to write data on the seemingly unused page. Reading
+ * an erased page will produce an ECC mismatch between generated and read
+ * ECC bytes that has to be dealt with separately.
+ */
+int gpmc_calculate_ecc(int cs, const u_char *dat, u_char *ecc_code)
+{
+	unsigned int val = 0x0;
+
+	if (gpmc_ecc_used != cs)
+		return -EINVAL;
+
+	/* read ecc result */
+	val = gpmc_read_reg(GPMC_ECC1_RESULT);
+	*ecc_code++ = val;          /* P128e, ..., P1e */
+	*ecc_code++ = val >> 16;    /* P128o, ..., P1o */
+	/* P2048o, P1024o, P512o, P256o, P2048e, P1024e, P512e, P256e */
+	*ecc_code++ = ((val >> 8) & 0x0f) | ((val >> 20) & 0xf0);
+
+	gpmc_ecc_used = -EINVAL;
+	return 0;
+}