memory: gpmc: Move omap gpmc code to live under drivers

Just move to drivers as further clean-up can now happen there
finally.

Let's also add Roger and me to the MAINTAINERS so we get
notified for any patches related to GPMC.

Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

3 files changed, 2103 insertions, 0 deletions

diff --git a/drivers/memory/Kconfig b/drivers/memory/Kconfig
index 6d91c27fd4c..6759de7ce20 100644
--- a/drivers/memory/Kconfig
+++ b/drivers/memory/Kconfig
@@ -41,6 +41,14 @@ config TI_EMIF
 	  parameters and other settings during frequency, voltage and
 	  temperature changes
 
+config OMAP_GPMC
+	bool
+	help
+	  This driver is for the General Purpose Memory Controller (GPMC)
+	  present on Texas Instruments SoCs (e.g. OMAP2+). GPMC allows
+	  interfacing to a variety of asynchronous as well as synchronous
+	  memory drives like NOR, NAND, OneNAND, SRAM.
+
 config MVEBU_DEVBUS
 	bool "Marvell EBU Device Bus Controller"
 	default y
diff --git a/drivers/memory/Makefile b/drivers/memory/Makefile
index c32d31981be..a7d410f3ca3 100644
--- a/drivers/memory/Makefile
+++ b/drivers/memory/Makefile
@@ -8,6 +8,7 @@ endif
 obj-$(CONFIG_ATMEL_SDRAMC)	+= atmel-sdramc.o
 obj-$(CONFIG_TI_AEMIF)		+= ti-aemif.o
 obj-$(CONFIG_TI_EMIF)		+= emif.o
+obj-$(CONFIG_OMAP_GPMC)		+= omap-gpmc.o
 obj-$(CONFIG_FSL_CORENET_CF)	+= fsl-corenet-cf.o
 obj-$(CONFIG_FSL_IFC)		+= fsl_ifc.o
 obj-$(CONFIG_MVEBU_DEVBUS)	+= mvebu-devbus.o
diff --git a/drivers/memory/omap-gpmc.c b/drivers/memory/omap-gpmc.c
new file mode 100644
index 00000000000..abfc0ddd076
--- /dev/null
+++ b/drivers/memory/omap-gpmc.c
@@ -0,0 +1,2094 @@
+/*
+ * 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 <linux/platform_device.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_mtd.h>
+#include <linux/of_device.h>
+#include <linux/omap-gpmc.h>
+#include <linux/mtd/nand.h>
+#include <linux/pm_runtime.h>
+
+#include <linux/platform_data/mtd-nand-omap2.h>
+#include <linux/platform_data/mtd-onenand-omap2.h>
+
+#include <asm/mach-types.h>
+
+#define	DEVICE_NAME		"omap-gpmc"
+
+/* 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_ECC_BCH_RESULT_0   0x240   /* not available on OMAP2 */
+#define	GPMC_ECC_BCH_RESULT_1	0x244	/* not available on OMAP2 */
+#define	GPMC_ECC_BCH_RESULT_2	0x248	/* not available on OMAP2 */
+#define	GPMC_ECC_BCH_RESULT_3	0x24c	/* not available on OMAP2 */
+#define	GPMC_ECC_BCH_RESULT_4	0x300	/* not available on OMAP2 */
+#define	GPMC_ECC_BCH_RESULT_5	0x304	/* not available on OMAP2 */
+#define	GPMC_ECC_BCH_RESULT_6	0x308	/* not available on OMAP2 */
+
+/* GPMC ECC control settings */
+#define GPMC_ECC_CTRL_ECCCLEAR		0x100
+#define GPMC_ECC_CTRL_ECCDISABLE	0x000
+#define GPMC_ECC_CTRL_ECCREG1		0x001
+#define GPMC_ECC_CTRL_ECCREG2		0x002
+#define GPMC_ECC_CTRL_ECCREG3		0x003
+#define GPMC_ECC_CTRL_ECCREG4		0x004
+#define GPMC_ECC_CTRL_ECCREG5		0x005
+#define GPMC_ECC_CTRL_ECCREG6		0x006
+#define GPMC_ECC_CTRL_ECCREG7		0x007
+#define GPMC_ECC_CTRL_ECCREG8		0x008
+#define GPMC_ECC_CTRL_ECCREG9		0x009
+
+#define GPMC_CONFIG_LIMITEDADDRESS		BIT(1)
+
+#define	GPMC_CONFIG2_CSEXTRADELAY		BIT(7)
+#define	GPMC_CONFIG3_ADVEXTRADELAY		BIT(7)
+#define	GPMC_CONFIG4_OEEXTRADELAY		BIT(7)
+#define	GPMC_CONFIG4_WEEXTRADELAY		BIT(23)
+#define	GPMC_CONFIG6_CYCLE2CYCLEDIFFCSEN	BIT(6)
+#define	GPMC_CONFIG6_CYCLE2CYCLESAMECSEN	BIT(7)
+
+#define GPMC_CS0_OFFSET		0x60
+#define GPMC_CS_SIZE		0x30
+#define	GPMC_BCH_SIZE		0x10
+
+#define GPMC_MEM_END		0x3FFFFFFF
+
+#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
+
+#define	GPMC_REVISION_MAJOR(l)		((l >> 4) & 0xf)
+#define	GPMC_REVISION_MINOR(l)		(l & 0xf)
+
+#define	GPMC_HAS_WR_ACCESS		0x1
+#define	GPMC_HAS_WR_DATA_MUX_BUS	0x2
+#define	GPMC_HAS_MUX_AAD		0x4
+
+#define GPMC_NR_WAITPINS		4
+
+#define GPMC_CS_CONFIG1		0x00
+#define GPMC_CS_CONFIG2		0x04
+#define GPMC_CS_CONFIG3		0x08
+#define GPMC_CS_CONFIG4		0x0c
+#define GPMC_CS_CONFIG5		0x10
+#define GPMC_CS_CONFIG6		0x14
+#define GPMC_CS_CONFIG7		0x18
+#define GPMC_CS_NAND_COMMAND	0x1c
+#define GPMC_CS_NAND_ADDRESS	0x20
+#define GPMC_CS_NAND_DATA	0x24
+
+/* Control Commands */
+#define GPMC_CONFIG_RDY_BSY	0x00000001
+#define GPMC_CONFIG_DEV_SIZE	0x00000002
+#define GPMC_CONFIG_DEV_TYPE	0x00000003
+#define GPMC_SET_IRQ_STATUS	0x00000004
+
+#define GPMC_CONFIG1_WRAPBURST_SUPP     (1 << 31)
+#define GPMC_CONFIG1_READMULTIPLE_SUPP  (1 << 30)
+#define GPMC_CONFIG1_READTYPE_ASYNC     (0 << 29)
+#define GPMC_CONFIG1_READTYPE_SYNC      (1 << 29)
+#define GPMC_CONFIG1_WRITEMULTIPLE_SUPP (1 << 28)
+#define GPMC_CONFIG1_WRITETYPE_ASYNC    (0 << 27)
+#define GPMC_CONFIG1_WRITETYPE_SYNC     (1 << 27)
+#define GPMC_CONFIG1_CLKACTIVATIONTIME(val) ((val & 3) << 25)
+#define GPMC_CONFIG1_PAGE_LEN(val)      ((val & 3) << 23)
+#define GPMC_CONFIG1_WAIT_READ_MON      (1 << 22)
+#define GPMC_CONFIG1_WAIT_WRITE_MON     (1 << 21)
+#define GPMC_CONFIG1_WAIT_MON_IIME(val) ((val & 3) << 18)
+#define GPMC_CONFIG1_WAIT_PIN_SEL(val)  ((val & 3) << 16)
+#define GPMC_CONFIG1_DEVICESIZE(val)    ((val & 3) << 12)
+#define GPMC_CONFIG1_DEVICESIZE_16      GPMC_CONFIG1_DEVICESIZE(1)
+#define GPMC_CONFIG1_DEVICETYPE(val)    ((val & 3) << 10)
+#define GPMC_CONFIG1_DEVICETYPE_NOR     GPMC_CONFIG1_DEVICETYPE(0)
+#define GPMC_CONFIG1_MUXTYPE(val)       ((val & 3) << 8)
+#define GPMC_CONFIG1_TIME_PARA_GRAN     (1 << 4)
+#define GPMC_CONFIG1_FCLK_DIV(val)      (val & 3)
+#define GPMC_CONFIG1_FCLK_DIV2          (GPMC_CONFIG1_FCLK_DIV(1))
+#define GPMC_CONFIG1_FCLK_DIV3          (GPMC_CONFIG1_FCLK_DIV(2))
+#define GPMC_CONFIG1_FCLK_DIV4          (GPMC_CONFIG1_FCLK_DIV(3))
+#define GPMC_CONFIG7_CSVALID		(1 << 6)
+
+#define GPMC_DEVICETYPE_NOR		0
+#define GPMC_DEVICETYPE_NAND		2
+#define GPMC_CONFIG_WRITEPROTECT	0x00000010
+#define WR_RD_PIN_MONITORING		0x00600000
+
+#define GPMC_ENABLE_IRQ		0x0000000d
+
+/* ECC commands */
+#define GPMC_ECC_READ		0 /* Reset Hardware ECC for read */
+#define GPMC_ECC_WRITE		1 /* Reset Hardware ECC for write */
+#define GPMC_ECC_READSYN	2 /* Reset before syndrom is read back */
+
+/* XXX: Only NAND irq has been considered,currently these are the only ones used
+ */
+#define	GPMC_NR_IRQ		2
+
+struct gpmc_cs_data {
+	const char *name;
+
+#define GPMC_CS_RESERVED	(1 << 0)
+	u32 flags;
+
+	struct resource mem;
+};
+
+struct gpmc_client_irq	{
+	unsigned		irq;
+	u32			bitmask;
+};
+
+/* 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 gpmc_client_irq gpmc_client_irq[GPMC_NR_IRQ];
+static struct irq_chip gpmc_irq_chip;
+static int gpmc_irq_start;
+
+static struct resource	gpmc_mem_root;
+static struct gpmc_cs_data gpmc_cs[GPMC_CS_NUM];
+static DEFINE_SPINLOCK(gpmc_mem_lock);
+/* Define chip-selects as reserved by default until probe completes */
+static unsigned int gpmc_cs_num = GPMC_CS_NUM;
+static unsigned int gpmc_nr_waitpins;
+static struct device *gpmc_dev;
+static int gpmc_irq;
+static resource_size_t phys_base, mem_size;
+static unsigned gpmc_capability;
+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)
+{
+	writel_relaxed(val, gpmc_base + idx);
+}
+
+static u32 gpmc_read_reg(int idx)
+{
+	return readl_relaxed(gpmc_base + idx);
+}
+
+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;
+	writel_relaxed(val, reg_addr);
+}
+
+static 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 readl_relaxed(reg_addr);
+}
+
+/* TODO: Add support for gpmc_fck to clock framework and use it */
+static unsigned long gpmc_get_fclk_period(void)
+{
+	unsigned long rate = clk_get_rate(gpmc_l3_clk);
+
+	rate /= 1000;
+	rate = 1000000000 / rate;	/* In picoseconds */
+
+	return rate;
+}
+
+static 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;
+}
+
+static 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;
+}
+
+static unsigned int gpmc_ticks_to_ps(unsigned int ticks)
+{
+	return ticks * gpmc_get_fclk_period();
+}
+
+static unsigned int gpmc_round_ps_to_ticks(unsigned int time_ps)
+{
+	unsigned long ticks = gpmc_ps_to_ticks(time_ps);
+
+	return ticks * gpmc_get_fclk_period();
+}
+
+static inline void gpmc_cs_modify_reg(int cs, int reg, u32 mask, bool value)
+{
+	u32 l;
+
+	l = gpmc_cs_read_reg(cs, reg);
+	if (value)
+		l |= mask;
+	else
+		l &= ~mask;
+	gpmc_cs_write_reg(cs, reg, l);
+}
+
+static void gpmc_cs_bool_timings(int cs, const struct gpmc_bool_timings *p)
+{
+	gpmc_cs_modify_reg(cs, GPMC_CS_CONFIG1,
+			   GPMC_CONFIG1_TIME_PARA_GRAN,
+			   p->time_para_granularity);
+	gpmc_cs_modify_reg(cs, GPMC_CS_CONFIG2,
+			   GPMC_CONFIG2_CSEXTRADELAY, p->cs_extra_delay);
+	gpmc_cs_modify_reg(cs, GPMC_CS_CONFIG3,
+			   GPMC_CONFIG3_ADVEXTRADELAY, p->adv_extra_delay);
+	gpmc_cs_modify_reg(cs, GPMC_CS_CONFIG4,
+			   GPMC_CONFIG4_OEEXTRADELAY, p->oe_extra_delay);
+	gpmc_cs_modify_reg(cs, GPMC_CS_CONFIG4,
+			   GPMC_CONFIG4_OEEXTRADELAY, p->we_extra_delay);
+	gpmc_cs_modify_reg(cs, GPMC_CS_CONFIG6,
+			   GPMC_CONFIG6_CYCLE2CYCLESAMECSEN,
+			   p->cycle2cyclesamecsen);
+	gpmc_cs_modify_reg(cs, GPMC_CS_CONFIG6,
+			   GPMC_CONFIG6_CYCLE2CYCLEDIFFCSEN,
+			   p->cycle2cyclediffcsen);
+}
+
+#ifdef DEBUG
+static int get_gpmc_timing_reg(int cs, int reg, int st_bit, int end_bit,
+			       bool raw, bool noval, int shift,
+			       const char *name)
+{
+	u32 l;
+	int nr_bits, max_value, mask;
+
+	l = gpmc_cs_read_reg(cs, reg);
+	nr_bits = end_bit - st_bit + 1;
+	max_value = (1 << nr_bits) - 1;
+	mask = max_value << st_bit;
+	l = (l & mask) >> st_bit;
+	if (shift)
+		l = (shift << l);
+	if (noval && (l == 0))
+		return 0;
+	if (!raw) {
+		unsigned int time_ns_min, time_ns, time_ns_max;
+
+		time_ns_min = gpmc_ticks_to_ns(l ? l - 1 : 0);
+		time_ns = gpmc_ticks_to_ns(l);
+		time_ns_max = gpmc_ticks_to_ns(l + 1 > max_value ?
+					       max_value : l + 1);
+		pr_info("gpmc,%s = <%u> (%u - %u ns, %i ticks)\n",
+			name, time_ns, time_ns_min, time_ns_max, l);
+	} else {
+		pr_info("gpmc,%s = <%u>\n", name, l);
+	}
+
+	return l;
+}
+
+#define GPMC_PRINT_CONFIG(cs, config) \
+	pr_info("cs%i %s: 0x%08x\n", cs, #config, \
+		gpmc_cs_read_reg(cs, config))
+#define GPMC_GET_RAW(reg, st, end, field) \
+	get_gpmc_timing_reg(cs, (reg), (st), (end), 1, 0, 0, field)
+#define GPMC_GET_RAW_BOOL(reg, st, end, field) \
+	get_gpmc_timing_reg(cs, (reg), (st), (end), 1, 1, 0, field)
+#define GPMC_GET_RAW_SHIFT(reg, st, end, shift, field) \
+	get_gpmc_timing_reg(cs, (reg), (st), (end), 1, 1, (shift), field)
+#define GPMC_GET_TICKS(reg, st, end, field) \
+	get_gpmc_timing_reg(cs, (reg), (st), (end), 0, 0, 0, field)
+
+static void gpmc_show_regs(int cs, const char *desc)
+{
+	pr_info("gpmc cs%i %s:\n", cs, desc);
+	GPMC_PRINT_CONFIG(cs, GPMC_CS_CONFIG1);
+	GPMC_PRINT_CONFIG(cs, GPMC_CS_CONFIG2);
+	GPMC_PRINT_CONFIG(cs, GPMC_CS_CONFIG3);
+	GPMC_PRINT_CONFIG(cs, GPMC_CS_CONFIG4);
+	GPMC_PRINT_CONFIG(cs, GPMC_CS_CONFIG5);
+	GPMC_PRINT_CONFIG(cs, GPMC_CS_CONFIG6);
+}
+
+/*
+ * Note that gpmc,wait-pin handing wrongly assumes bit 8 is available,
+ * see commit c9fb809.
+ */
+static void gpmc_cs_show_timings(int cs, const char *desc)
+{
+	gpmc_show_regs(cs, desc);
+
+	pr_info("gpmc cs%i access configuration:\n", cs);
+	GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG1,  4,  4, "time-para-granularity");
+	GPMC_GET_RAW(GPMC_CS_CONFIG1,  8,  9, "mux-add-data");
+	GPMC_GET_RAW(GPMC_CS_CONFIG1, 12, 13, "device-width");
+	GPMC_GET_RAW(GPMC_CS_CONFIG1, 16, 17, "wait-pin");
+	GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG1, 21, 21, "wait-on-write");
+	GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG1, 22, 22, "wait-on-read");
+	GPMC_GET_RAW_SHIFT(GPMC_CS_CONFIG1, 23, 24, 4, "burst-length");
+	GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG1, 27, 27, "sync-write");
+	GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG1, 28, 28, "burst-write");
+	GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG1, 29, 29, "gpmc,sync-read");
+	GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG1, 30, 30, "burst-read");
+	GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG1, 31, 31, "burst-wrap");
+
+	GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG2,  7,  7, "cs-extra-delay");
+
+	GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG3,  7,  7, "adv-extra-delay");
+
+	GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG4, 23, 23, "we-extra-delay");
+	GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG4,  7,  7, "oe-extra-delay");
+
+	GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG6,  7,  7, "cycle2cycle-samecsen");
+	GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG6,  6,  6, "cycle2cycle-diffcsen");
+
+	pr_info("gpmc cs%i timings configuration:\n", cs);
+	GPMC_GET_TICKS(GPMC_CS_CONFIG2,  0,  3, "cs-on-ns");
+	GPMC_GET_TICKS(GPMC_CS_CONFIG2,  8, 12, "cs-rd-off-ns");
+	GPMC_GET_TICKS(GPMC_CS_CONFIG2, 16, 20, "cs-wr-off-ns");
+
+	GPMC_GET_TICKS(GPMC_CS_CONFIG3,  0,  3, "adv-on-ns");
+	GPMC_GET_TICKS(GPMC_CS_CONFIG3,  8, 12, "adv-rd-off-ns");
+	GPMC_GET_TICKS(GPMC_CS_CONFIG3, 16, 20, "adv-wr-off-ns");
+
+	GPMC_GET_TICKS(GPMC_CS_CONFIG4,  0,  3, "oe-on-ns");
+	GPMC_GET_TICKS(GPMC_CS_CONFIG4,  8, 12, "oe-off-ns");
+	GPMC_GET_TICKS(GPMC_CS_CONFIG4, 16, 19, "we-on-ns");
+	GPMC_GET_TICKS(GPMC_CS_CONFIG4, 24, 28, "we-off-ns");
+
+	GPMC_GET_TICKS(GPMC_CS_CONFIG5,  0,  4, "rd-cycle-ns");
+	GPMC_GET_TICKS(GPMC_CS_CONFIG5,  8, 12, "wr-cycle-ns");
+	GPMC_GET_TICKS(GPMC_CS_CONFIG5, 16, 20, "access-ns");
+
+	GPMC_GET_TICKS(GPMC_CS_CONFIG5, 24, 27, "page-burst-access-ns");
+
+	GPMC_GET_TICKS(GPMC_CS_CONFIG6, 0, 3, "bus-turnaround-ns");
+	GPMC_GET_TICKS(GPMC_CS_CONFIG6, 8, 11, "cycle2cycle-delay-ns");
+
+	GPMC_GET_TICKS(GPMC_CS_CONFIG1, 18, 19, "wait-monitoring-ns");
+	GPMC_GET_TICKS(GPMC_CS_CONFIG1, 25, 26, "clk-activation-ns");
+
+	GPMC_GET_TICKS(GPMC_CS_CONFIG6, 16, 19, "wr-data-mux-bus-ns");
+	GPMC_GET_TICKS(GPMC_CS_CONFIG6, 24, 28, "wr-access-ns");
+}
+#else
+static inline void gpmc_cs_show_timings(int cs, const char *desc)
+{
+}
+#endif
+
+static int set_gpmc_timing_reg(int cs, int reg, int st_bit, int end_bit,
+			       int time, const char *name)
+{
+	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;
+	mask = (1 << nr_bits) - 1;
+
+	if (ticks > mask) {
+		pr_err("%s: GPMC error! CS%d: %s: %d ns, %d ticks > %d\n",
+		       __func__, cs, name, time, ticks, mask);
+
+		return -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;
+}
+
+#define GPMC_SET_ONE(reg, st, end, field) \
+	if (set_gpmc_timing_reg(cs, (reg), (st), (end),		\
+			t->field, #field) < 0)			\
+		return -1
+
+int gpmc_calc_divider(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;
+
+	gpmc_cs_show_timings(cs, "before gpmc_cs_set_timings");
+	div = gpmc_calc_divider(t->sync_clk);
+	if (div < 0)
+		return div;
+
+	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);
+
+	GPMC_SET_ONE(GPMC_CS_CONFIG6, 0, 3, bus_turnaround);
+	GPMC_SET_ONE(GPMC_CS_CONFIG6, 8, 11, cycle2cycle_delay);
+
+	GPMC_SET_ONE(GPMC_CS_CONFIG1, 18, 19, wait_monitoring);
+	GPMC_SET_ONE(GPMC_CS_CONFIG1, 25, 26, clk_activation);
+
+	if (gpmc_capability & GPMC_HAS_WR_DATA_MUX_BUS)
+		GPMC_SET_ONE(GPMC_CS_CONFIG6, 16, 19, wr_data_mux_bus);
+	if (gpmc_capability & GPMC_HAS_WR_ACCESS)
+		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);
+	}
+
+	gpmc_cs_bool_timings(cs, &t->bool_timings);
+	gpmc_cs_show_timings(cs, "after gpmc_cs_set_timings");
+
+	return 0;
+}
+
+static int gpmc_cs_set_memconf(int cs, u32 base, u32 size)
+{
+	u32 l;
+	u32 mask;
+
+	/*
+	 * Ensure that base address is aligned on a
+	 * boundary equal to or greater than size.
+	 */
+	if (base & (size - 1))
+		return -EINVAL;
+
+	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);
+
+	return 0;
+}
+
+static void gpmc_cs_enable_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_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;
+}
+
+static void gpmc_cs_set_reserved(int cs, int reserved)
+{
+	struct gpmc_cs_data *gpmc = &gpmc_cs[cs];
+
+	gpmc->flags |= GPMC_CS_RESERVED;
+}
+
+static bool gpmc_cs_reserved(int cs)
+{
+	struct gpmc_cs_data *gpmc = &gpmc_cs[cs];
+
+	return gpmc->flags & GPMC_CS_RESERVED;
+}
+
+static void gpmc_cs_set_name(int cs, const char *name)
+{
+	struct gpmc_cs_data *gpmc = &gpmc_cs[cs];
+
+	gpmc->name = name;
+}
+
+const char *gpmc_cs_get_name(int cs)
+{
+	struct gpmc_cs_data *gpmc = &gpmc_cs[cs];
+
+	return gpmc->name;
+}
+
+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 gpmc_cs_data *gpmc = &gpmc_cs[cs];
+	struct resource *res = &gpmc->mem;
+	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;
+}
+
+static int gpmc_cs_delete_mem(int cs)
+{
+	struct gpmc_cs_data *gpmc = &gpmc_cs[cs];
+	struct resource *res = &gpmc->mem;
+	int r;
+
+	spin_lock(&gpmc_mem_lock);
+	r = release_resource(res);
+	res->start = 0;
+	res->end = 0;
+	spin_unlock(&gpmc_mem_lock);
+
+	return r;
+}
+
+/**
+ * gpmc_cs_remap - remaps a chip-select physical base address
+ * @cs:		chip-select to remap
+ * @base:	physical base address to re-map chip-select to
+ *
+ * Re-maps a chip-select to a new physical base address specified by
+ * "base". Returns 0 on success and appropriate negative error code
+ * on failure.
+ */
+static int gpmc_cs_remap(int cs, u32 base)
+{
+	int ret;
+	u32 old_base, size;
+
+	if (cs > gpmc_cs_num) {
+		pr_err("%s: requested chip-select is disabled\n", __func__);
+		return -ENODEV;
+	}
+
+	/*
+	 * Make sure we ignore any device offsets from the GPMC partition
+	 * allocated for the chip select and that the new base confirms
+	 * to the GPMC 16MB minimum granularity.
+	 */ 
+	base &= ~(SZ_16M - 1);
+
+	gpmc_cs_get_memconf(cs, &old_base, &size);
+	if (base == old_base)
+		return 0;
+
+	ret = gpmc_cs_delete_mem(cs);
+	if (ret < 0)
+		return ret;
+
+	ret = gpmc_cs_insert_mem(cs, base, size);
+	if (ret < 0)
+		return ret;
+
+	ret = gpmc_cs_set_memconf(cs, base, size);
+
+	return ret;
+}
+
+int gpmc_cs_request(int cs, unsigned long size, unsigned long *base)
+{
+	struct gpmc_cs_data *gpmc = &gpmc_cs[cs];
+	struct resource *res = &gpmc->mem;
+	int r = -1;
+
+	if (cs > gpmc_cs_num) {
+		pr_err("%s: requested chip-select is disabled\n", __func__);
+		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;
+
+	/* Disable CS while changing base address and size mask */
+	gpmc_cs_disable_mem(cs);
+
+	r = gpmc_cs_set_memconf(cs, res->start, resource_size(res));
+	if (r < 0) {
+		release_resource(res);
+		goto out;
+	}
+
+	/* Enable CS */
+	gpmc_cs_enable_mem(cs);
+	*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)
+{
+	struct gpmc_cs_data *gpmc = &gpmc_cs[cs];
+	struct resource *res = &gpmc->mem;
+
+	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);
+	if (res->flags)
+		release_resource(res);
+	gpmc_cs_set_reserved(cs, 0);
+	spin_unlock(&gpmc_mem_lock);
+}
+EXPORT_SYMBOL(gpmc_cs_free);
+
+/**
+ * gpmc_configure - write request to configure gpmc
+ * @cmd: command type
+ * @wval: value to write
+ * @return status of the operation
+ */
+int gpmc_configure(int cmd, int wval)
+{
+	u32 regval;
+
+	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;
+
+	default:
+		pr_err("%s: command not supported\n", __func__);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(gpmc_configure);
+
+void gpmc_update_nand_reg(struct gpmc_nand_regs *reg, int cs)
+{
+	int i;
+
+	reg->gpmc_status = gpmc_base + GPMC_STATUS;
+	reg->gpmc_nand_command = gpmc_base + GPMC_CS0_OFFSET +
+				GPMC_CS_NAND_COMMAND + GPMC_CS_SIZE * cs;
+	reg->gpmc_nand_address = gpmc_base + GPMC_CS0_OFFSET +
+				GPMC_CS_NAND_ADDRESS + GPMC_CS_SIZE * cs;
+	reg->gpmc_nand_data = gpmc_base + GPMC_CS0_OFFSET +
+				GPMC_CS_NAND_DATA + GPMC_CS_SIZE * cs;
+	reg->gpmc_prefetch_config1 = gpmc_base + GPMC_PREFETCH_CONFIG1;
+	reg->gpmc_prefetch_config2 = gpmc_base + GPMC_PREFETCH_CONFIG2;
+	reg->gpmc_prefetch_control = gpmc_base + GPMC_PREFETCH_CONTROL;
+	reg->gpmc_prefetch_status = gpmc_base + GPMC_PREFETCH_STATUS;
+	reg->gpmc_ecc_config = gpmc_base + GPMC_ECC_CONFIG;
+	reg->gpmc_ecc_control = gpmc_base + GPMC_ECC_CONTROL;
+	reg->gpmc_ecc_size_config = gpmc_base + GPMC_ECC_SIZE_CONFIG;
+	reg->gpmc_ecc1_result = gpmc_base + GPMC_ECC1_RESULT;
+
+	for (i = 0; i < GPMC_BCH_NUM_REMAINDER; i++) {
+		reg->gpmc_bch_result0[i] = gpmc_base + GPMC_ECC_BCH_RESULT_0 +
+					   GPMC_BCH_SIZE * i;
+		reg->gpmc_bch_result1[i] = gpmc_base + GPMC_ECC_BCH_RESULT_1 +
+					   GPMC_BCH_SIZE * i;
+		reg->gpmc_bch_result2[i] = gpmc_base + GPMC_ECC_BCH_RESULT_2 +
+					   GPMC_BCH_SIZE * i;
+		reg->gpmc_bch_result3[i] = gpmc_base + GPMC_ECC_BCH_RESULT_3 +
+					   GPMC_BCH_SIZE * i;
+		reg->gpmc_bch_result4[i] = gpmc_base + GPMC_ECC_BCH_RESULT_4 +
+					   i * GPMC_BCH_SIZE;
+		reg->gpmc_bch_result5[i] = gpmc_base + GPMC_ECC_BCH_RESULT_5 +
+					   i * GPMC_BCH_SIZE;
+		reg->gpmc_bch_result6[i] = gpmc_base + GPMC_ECC_BCH_RESULT_6 +
+					   i * GPMC_BCH_SIZE;
+	}
+}
+
+int gpmc_get_client_irq(unsigned irq_config)
+{
+	int i;
+
+	if (hweight32(irq_config) > 1)
+		return 0;
+
+	for (i = 0; i < GPMC_NR_IRQ; i++)
+		if (gpmc_client_irq[i].bitmask & irq_config)
+			return gpmc_client_irq[i].irq;
+
+	return 0;
+}
+
+static int gpmc_irq_endis(unsigned irq, bool endis)
+{
+	int i;
+	u32 regval;
+
+	for (i = 0; i < GPMC_NR_IRQ; i++)
+		if (irq == gpmc_client_irq[i].irq) {
+			regval = gpmc_read_reg(GPMC_IRQENABLE);
+			if (endis)
+				regval |= gpmc_client_irq[i].bitmask;
+			else
+				regval &= ~gpmc_client_irq[i].bitmask;
+			gpmc_write_reg(GPMC_IRQENABLE, regval);
+			break;
+		}
+
+	return 0;
+}
+
+static void gpmc_irq_disable(struct irq_data *p)
+{
+	gpmc_irq_endis(p->irq, false);
+}
+
+static void gpmc_irq_enable(struct irq_data *p)
+{
+	gpmc_irq_endis(p->irq, true);
+}
+
+static void gpmc_irq_noop(struct irq_data *data) { }
+
+static unsigned int gpmc_irq_noop_ret(struct irq_data *data) { return 0; }
+
+static int gpmc_setup_irq(void)
+{
+	int i;
+	u32 regval;
+
+	if (!gpmc_irq)
+		return -EINVAL;
+
+	gpmc_irq_start = irq_alloc_descs(-1, 0, GPMC_NR_IRQ, 0);
+	if (gpmc_irq_start < 0) {
+		pr_err("irq_alloc_descs failed\n");
+		return gpmc_irq_start;
+	}
+
+	gpmc_irq_chip.name = "gpmc";
+	gpmc_irq_chip.irq_startup = gpmc_irq_noop_ret;
+	gpmc_irq_chip.irq_enable = gpmc_irq_enable;
+	gpmc_irq_chip.irq_disable = gpmc_irq_disable;
+	gpmc_irq_chip.irq_shutdown = gpmc_irq_noop;
+	gpmc_irq_chip.irq_ack = gpmc_irq_noop;
+	gpmc_irq_chip.irq_mask = gpmc_irq_noop;
+	gpmc_irq_chip.irq_unmask = gpmc_irq_noop;
+
+	gpmc_client_irq[0].bitmask = GPMC_IRQ_FIFOEVENTENABLE;
+	gpmc_client_irq[1].bitmask = GPMC_IRQ_COUNT_EVENT;
+
+	for (i = 0; i < GPMC_NR_IRQ; i++) {
+		gpmc_client_irq[i].irq = gpmc_irq_start + i;
+		irq_set_chip_and_handler(gpmc_client_irq[i].irq,
+					&gpmc_irq_chip, handle_simple_irq);
+		set_irq_flags(gpmc_client_irq[i].irq,
+				IRQF_VALID | IRQF_NOAUTOEN);
+	}
+
+	/* Disable interrupts */
+	gpmc_write_reg(GPMC_IRQENABLE, 0);
+
+	/* clear interrupts */
+	regval = gpmc_read_reg(GPMC_IRQSTATUS);
+	gpmc_write_reg(GPMC_IRQSTATUS, regval);
+
+	return request_irq(gpmc_irq, gpmc_handle_irq, 0, "gpmc", NULL);
+}
+
+static int gpmc_free_irq(void)
+{
+	int i;
+
+	if (gpmc_irq)
+		free_irq(gpmc_irq, NULL);
+
+	for (i = 0; i < GPMC_NR_IRQ; i++) {
+		irq_set_handler(gpmc_client_irq[i].irq, NULL);
+		irq_set_chip(gpmc_client_irq[i].irq, &no_irq_chip);
+		irq_modify_status(gpmc_client_irq[i].irq, 0, 0);
+	}
+
+	irq_free_descs(gpmc_irq_start, GPMC_NR_IRQ);
+
+	return 0;
+}
+
+static void gpmc_mem_exit(void)
+{
+	int cs;
+
+	for (cs = 0; cs < gpmc_cs_num; cs++) {
+		if (!gpmc_cs_mem_enabled(cs))
+			continue;
+		gpmc_cs_delete_mem(cs);
+	}
+
+}
+
+static void gpmc_mem_init(void)
+{
+	int cs;
+
+	/*
+	 * The first 1MB of GPMC address space is typically mapped to
+	 * the internal ROM. Never allocate the first page, to
+	 * facilitate bug detection; even if we didn't boot from ROM.
+	 */
+	gpmc_mem_root.start = SZ_1M;
+	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)) {
+			pr_warn("%s: disabling cs %d mapped at 0x%x-0x%x\n",
+				__func__, cs, base, base + size);
+			gpmc_cs_disable_mem(cs);
+		}
+	}
+}
+
+static u32 gpmc_round_ps_to_sync_clk(u32 time_ps, u32 sync_clk)
+{
+	u32 temp;
+	int div;
+
+	div = gpmc_calc_divider(sync_clk);
+	temp = gpmc_ps_to_ticks(time_ps);
+	temp = (temp + div - 1) / div;
+	return gpmc_ticks_to_ps(temp * div);
+}
+
+/* XXX: can the cycles be avoided ? */
+static int gpmc_calc_sync_read_timings(struct gpmc_timings *gpmc_t,
+				       struct gpmc_device_timings *dev_t,
+				       bool mux)
+{
+	u32 temp;
+
+	/* adv_rd_off */
+	temp = dev_t->t_avdp_r;
+	/* XXX: mux check required ? */
+	if (mux) {
+		/* XXX: t_avdp not to be required for sync, only added for tusb
+		 * this indirectly necessitates requirement of t_avdp_r and
+		 * t_avdp_w instead of having a single t_avdp
+		 */
+		temp = max_t(u32, temp,	gpmc_t->clk_activation + dev_t->t_avdh);
+		temp = max_t(u32, gpmc_t->adv_on + gpmc_ticks_to_ps(1), temp);
+	}
+	gpmc_t->adv_rd_off = gpmc_round_ps_to_ticks(temp);
+
+	/* oe_on */
+	temp = dev_t->t_oeasu; /* XXX: remove this ? */
+	if (mux) {
+		temp = max_t(u32, temp,	gpmc_t->clk_activation + dev_t->t_ach);
+		temp = max_t(u32, temp, gpmc_t->adv_rd_off +
+				gpmc_ticks_to_ps(dev_t->cyc_aavdh_oe));
+	}
+	gpmc_t->oe_on = gpmc_round_ps_to_ticks(temp);
+
+	/* access */
+	/* XXX: any scope for improvement ?, by combining oe_on
+	 * and clk_activation, need to check whether
+	 * access = clk_activation + round to sync clk ?
+	 */
+	temp = max_t(u32, dev_t->t_iaa,	dev_t->cyc_iaa * gpmc_t->sync_clk);
+	temp += gpmc_t->clk_activation;
+	if (dev_t->cyc_oe)
+		temp = max_t(u32, temp, gpmc_t->oe_on +
+				gpmc_ticks_to_ps(dev_t->cyc_oe));
+	gpmc_t->access = gpmc_round_ps_to_ticks(temp);
+
+	gpmc_t->oe_off = gpmc_t->access + gpmc_ticks_to_ps(1);
+	gpmc_t->cs_rd_off = gpmc_t->oe_off;
+
+	/* rd_cycle */
+	temp = max_t(u32, dev_t->t_cez_r, dev_t->t_oez);
+	temp = gpmc_round_ps_to_sync_clk(temp, gpmc_t->sync_clk) +
+							gpmc_t->access;
+	/* XXX: barter t_ce_rdyz with t_cez_r ? */
+	if (dev_t->t_ce_rdyz)
+		temp = max_t(u32, temp,	gpmc_t->cs_rd_off + dev_t->t_ce_rdyz);
+	gpmc_t->rd_cycle = gpmc_round_ps_to_ticks(temp);
+
+	return 0;
+}
+
+static int gpmc_calc_sync_write_timings(struct gpmc_timings *gpmc_t,
+					struct gpmc_device_timings *dev_t,
+					bool mux)
+{
+	u32 temp;
+
+	/* adv_wr_off */
+	temp = dev_t->t_avdp_w;
+	if (mux) {
+		temp = max_t(u32, temp,
+			gpmc_t->clk_activation + dev_t->t_avdh);
+		temp = max_t(u32, gpmc_t->adv_on + gpmc_ticks_to_ps(1), temp);
+	}
+	gpmc_t->adv_wr_off = gpmc_round_ps_to_ticks(temp);
+
+	/* wr_data_mux_bus */
+	temp = max_t(u32, dev_t->t_weasu,
+			gpmc_t->clk_activation + dev_t->t_rdyo);
+	/* XXX: shouldn't mux be kept as a whole for wr_data_mux_bus ?,
+	 * and in that case remember to handle we_on properly
+	 */
+	if (mux) {
+		temp = max_t(u32, temp,
+			gpmc_t->adv_wr_off + dev_t->t_aavdh);
+		temp = max_t(u32, temp, gpmc_t->adv_wr_off +
+				gpmc_ticks_to_ps(dev_t->cyc_aavdh_we));
+	}
+	gpmc_t->wr_data_mux_bus = gpmc_round_ps_to_ticks(temp);
+
+	/* we_on */
+	if (gpmc_capability & GPMC_HAS_WR_DATA_MUX_BUS)
+		gpmc_t->we_on = gpmc_round_ps_to_ticks(dev_t->t_weasu);
+	else
+		gpmc_t->we_on = gpmc_t->wr_data_mux_bus;
+
+	/* wr_access */
+	/* XXX: gpmc_capability check reqd ? , even if not, will not harm */
+	gpmc_t->wr_access = gpmc_t->access;
+
+	/* we_off */
+	temp = gpmc_t->we_on + dev_t->t_wpl;
+	temp = max_t(u32, temp,
+			gpmc_t->wr_access + gpmc_ticks_to_ps(1));
+	temp = max_t(u32, temp,
+		gpmc_t->we_on + gpmc_ticks_to_ps(dev_t->cyc_wpl));
+	gpmc_t->we_off = gpmc_round_ps_to_ticks(temp);
+
+	gpmc_t->cs_wr_off = gpmc_round_ps_to_ticks(gpmc_t->we_off +
+							dev_t->t_wph);
+
+	/* wr_cycle */
+	temp = gpmc_round_ps_to_sync_clk(dev_t->t_cez_w, gpmc_t->sync_clk);
+	temp += gpmc_t->wr_access;
+	/* XXX: barter t_ce_rdyz with t_cez_w ? */
+	if (dev_t->t_ce_rdyz)
+		temp = max_t(u32, temp,
+				 gpmc_t->cs_wr_off + dev_t->t_ce_rdyz);
+	gpmc_t->wr_cycle = gpmc_round_ps_to_ticks(temp);
+
+	return 0;
+}
+
+static int gpmc_calc_async_read_timings(struct gpmc_timings *gpmc_t,
+					struct gpmc_device_timings *dev_t,
+					bool mux)
+{
+	u32 temp;
+
+	/* adv_rd_off */
+	temp = dev_t->t_avdp_r;
+	if (mux)
+		temp = max_t(u32, gpmc_t->adv_on + gpmc_ticks_to_ps(1), temp);
+	gpmc_t->adv_rd_off = gpmc_round_ps_to_ticks(temp);
+
+	/* oe_on */
+	temp = dev_t->t_oeasu;
+	if (mux)
+		temp = max_t(u32, temp,
+			gpmc_t->adv_rd_off + dev_t->t_aavdh);
+	gpmc_t->oe_on = gpmc_round_ps_to_ticks(temp);
+
+	/* access */
+	temp = max_t(u32, dev_t->t_iaa, /* XXX: remove t_iaa in async ? */
+				gpmc_t->oe_on + dev_t->t_oe);
+	temp = max_t(u32, temp,
+				gpmc_t->cs_on + dev_t->t_ce);
+	temp = max_t(u32, temp,
+				gpmc_t->adv_on + dev_t->t_aa);
+	gpmc_t->access = gpmc_round_ps_to_ticks(temp);
+
+	gpmc_t->oe_off = gpmc_t->access + gpmc_ticks_to_ps(1);
+	gpmc_t->cs_rd_off = gpmc_t->oe_off;
+
+	/* rd_cycle */
+	temp = max_t(u32, dev_t->t_rd_cycle,
+			gpmc_t->cs_rd_off + dev_t->t_cez_r);
+	temp = max_t(u32, temp, gpmc_t->oe_off + dev_t->t_oez);
+	gpmc_t->rd_cycle = gpmc_round_ps_to_ticks(temp);
+
+	return 0;
+}
+
+static int gpmc_calc_async_write_timings(struct gpmc_timings *gpmc_t,
+					 struct gpmc_device_timings *dev_t,
+					 bool mux)
+{
+	u32 temp;
+
+	/* adv_wr_off */
+	temp = dev_t->t_avdp_w;
+	if (mux)
+		temp = max_t(u32, gpmc_t->adv_on + gpmc_ticks_to_ps(1), temp);
+	gpmc_t->adv_wr_off = gpmc_round_ps_to_ticks(temp);
+
+	/* wr_data_mux_bus */
+	temp = dev_t->t_weasu;
+	if (mux) {
+		temp = max_t(u32, temp,	gpmc_t->adv_wr_off + dev_t->t_aavdh);
+		temp = max_t(u32, temp, gpmc_t->adv_wr_off +
+				gpmc_ticks_to_ps(dev_t->cyc_aavdh_we));
+	}
+	gpmc_t->wr_data_mux_bus = gpmc_round_ps_to_ticks(temp);
+
+	/* we_on */
+	if (gpmc_capability & GPMC_HAS_WR_DATA_MUX_BUS)
+		gpmc_t->we_on = gpmc_round_ps_to_ticks(dev_t->t_weasu);
+	else
+		gpmc_t->we_on = gpmc_t->wr_data_mux_bus;
+
+	/* we_off */
+	temp = gpmc_t->we_on + dev_t->t_wpl;
+	gpmc_t->we_off = gpmc_round_ps_to_ticks(temp);
+
+	gpmc_t->cs_wr_off = gpmc_round_ps_to_ticks(gpmc_t->we_off +
+							dev_t->t_wph);
+
+	/* wr_cycle */
+	temp = max_t(u32, dev_t->t_wr_cycle,
+				gpmc_t->cs_wr_off + dev_t->t_cez_w);
+	gpmc_t->wr_cycle = gpmc_round_ps_to_ticks(temp);
+
+	return 0;
+}
+
+static int gpmc_calc_sync_common_timings(struct gpmc_timings *gpmc_t,
+			struct gpmc_device_timings *dev_t)
+{
+	u32 temp;
+
+	gpmc_t->sync_clk = gpmc_calc_divider(dev_t->clk) *
+						gpmc_get_fclk_period();
+
+	gpmc_t->page_burst_access = gpmc_round_ps_to_sync_clk(
+					dev_t->t_bacc,
+					gpmc_t->sync_clk);
+
+	temp = max_t(u32, dev_t->t_ces, dev_t->t_avds);
+	gpmc_t->clk_activation = gpmc_round_ps_to_ticks(temp);
+
+	if (gpmc_calc_divider(gpmc_t->sync_clk) != 1)
+		return 0;
+
+	if (dev_t->ce_xdelay)
+		gpmc_t->bool_timings.cs_extra_delay = true;
+	if (dev_t->avd_xdelay)
+		gpmc_t->bool_timings.adv_extra_delay = true;
+	if (dev_t->oe_xdelay)
+		gpmc_t->bool_timings.oe_extra_delay = true;
+	if (dev_t->we_xdelay)
+		gpmc_t->bool_timings.we_extra_delay = true;
+
+	return 0;
+}
+
+static int gpmc_calc_common_timings(struct gpmc_timings *gpmc_t,
+				    struct gpmc_device_timings *dev_t,
+				    bool sync)
+{
+	u32 temp;
+
+	/* cs_on */
+	gpmc_t->cs_on = gpmc_round_ps_to_ticks(dev_t->t_ceasu);
+
+	/* adv_on */
+	temp = dev_t->t_avdasu;
+	if (dev_t->t_ce_avd)
+		temp = max_t(u32, temp,
+				gpmc_t->cs_on + dev_t->t_ce_avd);
+	gpmc_t->adv_on = gpmc_round_ps_to_ticks(temp);
+
+	if (sync)
+		gpmc_calc_sync_common_timings(gpmc_t, dev_t);
+
+	return 0;
+}
+
+/* TODO: remove this function once all peripherals are confirmed to
+ * work with generic timing. Simultaneously gpmc_cs_set_timings()
+ * has to be modified to handle timings in ps instead of ns
+*/
+static void gpmc_convert_ps_to_ns(struct gpmc_timings *t)
+{
+	t->cs_on /= 1000;
+	t->cs_rd_off /= 1000;
+	t->cs_wr_off /= 1000;
+	t->adv_on /= 1000;
+	t->adv_rd_off /= 1000;
+	t->adv_wr_off /= 1000;
+	t->we_on /= 1000;
+	t->we_off /= 1000;
+	t->oe_on /= 1000;
+	t->oe_off /= 1000;
+	t->page_burst_access /= 1000;
+	t->access /= 1000;
+	t->rd_cycle /= 1000;
+	t->wr_cycle /= 1000;
+	t->bus_turnaround /= 1000;
+	t->cycle2cycle_delay /= 1000;
+	t->wait_monitoring /= 1000;
+	t->clk_activation /= 1000;
+	t->wr_access /= 1000;
+	t->wr_data_mux_bus /= 1000;
+}
+
+int gpmc_calc_timings(struct gpmc_timings *gpmc_t,
+		      struct gpmc_settings *gpmc_s,
+		      struct gpmc_device_timings *dev_t)
+{
+	bool mux = false, sync = false;
+
+	if (gpmc_s) {
+		mux = gpmc_s->mux_add_data ? true : false;
+		sync = (gpmc_s->sync_read || gpmc_s->sync_write);
+	}
+
+	memset(gpmc_t, 0, sizeof(*gpmc_t));
+
+	gpmc_calc_common_timings(gpmc_t, dev_t, sync);
+
+	if (gpmc_s && gpmc_s->sync_read)
+		gpmc_calc_sync_read_timings(gpmc_t, dev_t, mux);
+	else
+		gpmc_calc_async_read_timings(gpmc_t, dev_t, mux);
+
+	if (gpmc_s && gpmc_s->sync_write)
+		gpmc_calc_sync_write_timings(gpmc_t, dev_t, mux);
+	else
+		gpmc_calc_async_write_timings(gpmc_t, dev_t, mux);
+
+	/* TODO: remove, see function definition */
+	gpmc_convert_ps_to_ns(gpmc_t);
+
+	return 0;
+}
+
+/**
+ * gpmc_cs_program_settings - programs non-timing related settings
+ * @cs:		GPMC chip-select to program
+ * @p:		pointer to GPMC settings structure
+ *
+ * Programs non-timing related settings for a GPMC chip-select, such as
+ * bus-width, burst configuration, etc. Function should be called once
+ * for each chip-select that is being used and must be called before
+ * calling gpmc_cs_set_timings() as timing parameters in the CONFIG1
+ * register will be initialised to zero by this function. Returns 0 on
+ * success and appropriate negative error code on failure.
+ */
+int gpmc_cs_program_settings(int cs, struct gpmc_settings *p)
+{
+	u32 config1;
+
+	if ((!p->device_width) || (p->device_width > GPMC_DEVWIDTH_16BIT)) {
+		pr_err("%s: invalid width %d!", __func__, p->device_width);
+		return -EINVAL;
+	}
+
+	/* Address-data multiplexing not supported for NAND devices */
+	if (p->device_nand && p->mux_add_data) {
+		pr_err("%s: invalid configuration!\n", __func__);
+		return -EINVAL;
+	}
+
+	if ((p->mux_add_data > GPMC_MUX_AD) ||
+	    ((p->mux_add_data == GPMC_MUX_AAD) &&
+	     !(gpmc_capability & GPMC_HAS_MUX_AAD))) {
+		pr_err("%s: invalid multiplex configuration!\n", __func__);
+		return -EINVAL;
+	}
+
+	/* Page/burst mode supports lengths of 4, 8 and 16 bytes */
+	if (p->burst_read || p->burst_write) {
+		switch (p->burst_len) {
+		case GPMC_BURST_4:
+		case GPMC_BURST_8:
+		case GPMC_BURST_16:
+			break;
+		default:
+			pr_err("%s: invalid page/burst-length (%d)\n",
+			       __func__, p->burst_len);
+			return -EINVAL;
+		}
+	}
+
+	if (p->wait_pin > gpmc_nr_waitpins) {
+		pr_err("%s: invalid wait-pin (%d)\n", __func__, p->wait_pin);
+		return -EINVAL;
+	}
+
+	config1 = GPMC_CONFIG1_DEVICESIZE((p->device_width - 1));
+
+	if (p->sync_read)
+		config1 |= GPMC_CONFIG1_READTYPE_SYNC;
+	if (p->sync_write)
+		config1 |= GPMC_CONFIG1_WRITETYPE_SYNC;
+	if (p->wait_on_read)
+		config1 |= GPMC_CONFIG1_WAIT_READ_MON;
+	if (p->wait_on_write)
+		config1 |= GPMC_CONFIG1_WAIT_WRITE_MON;
+	if (p->wait_on_read || p->wait_on_write)
+		config1 |= GPMC_CONFIG1_WAIT_PIN_SEL(p->wait_pin);
+	if (p->device_nand)
+		config1	|= GPMC_CONFIG1_DEVICETYPE(GPMC_DEVICETYPE_NAND);
+	if (p->mux_add_data)
+		config1	|= GPMC_CONFIG1_MUXTYPE(p->mux_add_data);
+	if (p->burst_read)
+		config1 |= GPMC_CONFIG1_READMULTIPLE_SUPP;
+	if (p->burst_write)
+		config1 |= GPMC_CONFIG1_WRITEMULTIPLE_SUPP;
+	if (p->burst_read || p->burst_write) {
+		config1 |= GPMC_CONFIG1_PAGE_LEN(p->burst_len >> 3);
+		config1 |= p->burst_wrap ? GPMC_CONFIG1_WRAPBURST_SUPP : 0;
+	}
+
+	gpmc_cs_write_reg(cs, GPMC_CS_CONFIG1, config1);
+
+	return 0;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id gpmc_dt_ids[] = {
+	{ .compatible = "ti,omap2420-gpmc" },
+	{ .compatible = "ti,omap2430-gpmc" },
+	{ .compatible = "ti,omap3430-gpmc" },	/* omap3430 & omap3630 */
+	{ .compatible = "ti,omap4430-gpmc" },	/* omap4430 & omap4460 & omap543x */
+	{ .compatible = "ti,am3352-gpmc" },	/* am335x devices */
+	{ }
+};
+MODULE_DEVICE_TABLE(of, gpmc_dt_ids);
+
+/**
+ * gpmc_read_settings_dt - read gpmc settings from device-tree
+ * @np:		pointer to device-tree node for a gpmc child device
+ * @p:		pointer to gpmc settings structure
+ *
+ * Reads the GPMC settings for a GPMC child device from device-tree and
+ * stores them in the GPMC settings structure passed. The GPMC settings
+ * structure is initialised to zero by this function and so any
+ * previously stored settings will be cleared.
+ */
+void gpmc_read_settings_dt(struct device_node *np, struct gpmc_settings *p)
+{
+	memset(p, 0, sizeof(struct gpmc_settings));
+
+	p->sync_read = of_property_read_bool(np, "gpmc,sync-read");
+	p->sync_write = of_property_read_bool(np, "gpmc,sync-write");
+	of_property_read_u32(np, "gpmc,device-width", &p->device_width);
+	of_property_read_u32(np, "gpmc,mux-add-data", &p->mux_add_data);
+
+	if (!of_property_read_u32(np, "gpmc,burst-length", &p->burst_len)) {
+		p->burst_wrap = of_property_read_bool(np, "gpmc,burst-wrap");
+		p->burst_read = of_property_read_bool(np, "gpmc,burst-read");
+		p->burst_write = of_property_read_bool(np, "gpmc,burst-write");
+		if (!p->burst_read && !p->burst_write)
+			pr_warn("%s: page/burst-length set but not used!\n",
+				__func__);
+	}
+
+	if (!of_property_read_u32(np, "gpmc,wait-pin", &p->wait_pin)) {
+		p->wait_on_read = of_property_read_bool(np,
+							"gpmc,wait-on-read");
+		p->wait_on_write = of_property_read_bool(np,
+							 "gpmc,wait-on-write");
+		if (!p->wait_on_read && !p->wait_on_write)
+			pr_debug("%s: rd/wr wait monitoring not enabled!\n",
+				 __func__);
+	}
+}
+
+static void __maybe_unused gpmc_read_timings_dt(struct device_node *np,
+						struct gpmc_timings *gpmc_t)
+{
+	struct gpmc_bool_timings *p;
+
+	if (!np || !gpmc_t)
+		return;
+
+	memset(gpmc_t, 0, sizeof(*gpmc_t));
+
+	/* minimum clock period for syncronous mode */
+	of_property_read_u32(np, "gpmc,sync-clk-ps", &gpmc_t->sync_clk);
+
+	/* chip select timtings */
+	of_property_read_u32(np, "gpmc,cs-on-ns", &gpmc_t->cs_on);
+	of_property_read_u32(np, "gpmc,cs-rd-off-ns", &gpmc_t->cs_rd_off);
+	of_property_read_u32(np, "gpmc,cs-wr-off-ns", &gpmc_t->cs_wr_off);
+
+	/* ADV signal timings */
+	of_property_read_u32(np, "gpmc,adv-on-ns", &gpmc_t->adv_on);
+	of_property_read_u32(np, "gpmc,adv-rd-off-ns", &gpmc_t->adv_rd_off);
+	of_property_read_u32(np, "gpmc,adv-wr-off-ns", &gpmc_t->adv_wr_off);
+
+	/* WE signal timings */
+	of_property_read_u32(np, "gpmc,we-on-ns", &gpmc_t->we_on);
+	of_property_read_u32(np, "gpmc,we-off-ns", &gpmc_t->we_off);
+
+	/* OE signal timings */
+	of_property_read_u32(np, "gpmc,oe-on-ns", &gpmc_t->oe_on);
+	of_property_read_u32(np, "gpmc,oe-off-ns", &gpmc_t->oe_off);
+
+	/* access and cycle timings */
+	of_property_read_u32(np, "gpmc,page-burst-access-ns",
+			     &gpmc_t->page_burst_access);
+	of_property_read_u32(np, "gpmc,access-ns", &gpmc_t->access);
+	of_property_read_u32(np, "gpmc,rd-cycle-ns", &gpmc_t->rd_cycle);
+	of_property_read_u32(np, "gpmc,wr-cycle-ns", &gpmc_t->wr_cycle);
+	of_property_read_u32(np, "gpmc,bus-turnaround-ns",
+			     &gpmc_t->bus_turnaround);
+	of_property_read_u32(np, "gpmc,cycle2cycle-delay-ns",
+			     &gpmc_t->cycle2cycle_delay);
+	of_property_read_u32(np, "gpmc,wait-monitoring-ns",
+			     &gpmc_t->wait_monitoring);
+	of_property_read_u32(np, "gpmc,clk-activation-ns",
+			     &gpmc_t->clk_activation);
+
+	/* only applicable to OMAP3+ */
+	of_property_read_u32(np, "gpmc,wr-access-ns", &gpmc_t->wr_access);
+	of_property_read_u32(np, "gpmc,wr-data-mux-bus-ns",
+			     &gpmc_t->wr_data_mux_bus);
+
+	/* bool timing parameters */
+	p = &gpmc_t->bool_timings;
+
+	p->cycle2cyclediffcsen =
+		of_property_read_bool(np, "gpmc,cycle2cycle-diffcsen");
+	p->cycle2cyclesamecsen =
+		of_property_read_bool(np, "gpmc,cycle2cycle-samecsen");
+	p->we_extra_delay = of_property_read_bool(np, "gpmc,we-extra-delay");
+	p->oe_extra_delay = of_property_read_bool(np, "gpmc,oe-extra-delay");
+	p->adv_extra_delay = of_property_read_bool(np, "gpmc,adv-extra-delay");
+	p->cs_extra_delay = of_property_read_bool(np, "gpmc,cs-extra-delay");
+	p->time_para_granularity =
+		of_property_read_bool(np, "gpmc,time-para-granularity");
+}
+
+#if IS_ENABLED(CONFIG_MTD_NAND)
+
+static const char * const nand_xfer_types[] = {
+	[NAND_OMAP_PREFETCH_POLLED]		= "prefetch-polled",
+	[NAND_OMAP_POLLED]			= "polled",
+	[NAND_OMAP_PREFETCH_DMA]		= "prefetch-dma",
+	[NAND_OMAP_PREFETCH_IRQ]		= "prefetch-irq",
+};
+
+static int gpmc_probe_nand_child(struct platform_device *pdev,
+				 struct device_node *child)
+{
+	u32 val;
+	const char *s;
+	struct gpmc_timings gpmc_t;
+	struct omap_nand_platform_data *gpmc_nand_data;
+
+	if (of_property_read_u32(child, "reg", &val) < 0) {
+		dev_err(&pdev->dev, "%s has no 'reg' property\n",
+			child->full_name);
+		return -ENODEV;
+	}
+
+	gpmc_nand_data = devm_kzalloc(&pdev->dev, sizeof(*gpmc_nand_data),
+				      GFP_KERNEL);
+	if (!gpmc_nand_data)
+		return -ENOMEM;
+
+	gpmc_nand_data->cs = val;
+	gpmc_nand_data->of_node = child;
+
+	/* Detect availability of ELM module */
+	gpmc_nand_data->elm_of_node = of_parse_phandle(child, "ti,elm-id", 0);
+	if (gpmc_nand_data->elm_of_node == NULL)
+		gpmc_nand_data->elm_of_node =
+					of_parse_phandle(child, "elm_id", 0);
+	if (gpmc_nand_data->elm_of_node == NULL)
+		pr_warn("%s: ti,elm-id property not found\n", __func__);
+
+	/* select ecc-scheme for NAND */
+	if (of_property_read_string(child, "ti,nand-ecc-opt", &s)) {
+		pr_err("%s: ti,nand-ecc-opt not found\n", __func__);
+		return -ENODEV;
+	}
+
+	if (!strcmp(s, "sw"))
+		gpmc_nand_data->ecc_opt = OMAP_ECC_HAM1_CODE_SW;
+	else if (!strcmp(s, "ham1") ||
+		 !strcmp(s, "hw") || !strcmp(s, "hw-romcode"))
+		gpmc_nand_data->ecc_opt =
+				OMAP_ECC_HAM1_CODE_HW;
+	else if (!strcmp(s, "bch4"))
+		if (gpmc_nand_data->elm_of_node)
+			gpmc_nand_data->ecc_opt =
+				OMAP_ECC_BCH4_CODE_HW;
+		else
+			gpmc_nand_data->ecc_opt =
+				OMAP_ECC_BCH4_CODE_HW_DETECTION_SW;
+	else if (!strcmp(s, "bch8"))
+		if (gpmc_nand_data->elm_of_node)
+			gpmc_nand_data->ecc_opt =
+				OMAP_ECC_BCH8_CODE_HW;
+		else
+			gpmc_nand_data->ecc_opt =
+				OMAP_ECC_BCH8_CODE_HW_DETECTION_SW;
+	else if (!strcmp(s, "bch16"))
+		if (gpmc_nand_data->elm_of_node)
+			gpmc_nand_data->ecc_opt =
+				OMAP_ECC_BCH16_CODE_HW;
+		else
+			pr_err("%s: BCH16 requires ELM support\n", __func__);
+	else
+		pr_err("%s: ti,nand-ecc-opt invalid value\n", __func__);
+
+	/* select data transfer mode for NAND controller */
+	if (!of_property_read_string(child, "ti,nand-xfer-type", &s))
+		for (val = 0; val < ARRAY_SIZE(nand_xfer_types); val++)
+			if (!strcasecmp(s, nand_xfer_types[val])) {
+				gpmc_nand_data->xfer_type = val;
+				break;
+			}
+
+	gpmc_nand_data->flash_bbt = of_get_nand_on_flash_bbt(child);
+
+	val = of_get_nand_bus_width(child);
+	if (val == 16)
+		gpmc_nand_data->devsize = NAND_BUSWIDTH_16;
+
+	gpmc_read_timings_dt(child, &gpmc_t);
+	gpmc_nand_init(gpmc_nand_data, &gpmc_t);
+
+	return 0;
+}
+#else
+static int gpmc_probe_nand_child(struct platform_device *pdev,
+				 struct device_node *child)
+{
+	return 0;
+}
+#endif
+
+#if IS_ENABLED(CONFIG_MTD_ONENAND)
+static int gpmc_probe_onenand_child(struct platform_device *pdev,
+				 struct device_node *child)
+{
+	u32 val;
+	struct omap_onenand_platform_data *gpmc_onenand_data;
+
+	if (of_property_read_u32(child, "reg", &val) < 0) {
+		dev_err(&pdev->dev, "%s has no 'reg' property\n",
+			child->full_name);
+		return -ENODEV;
+	}
+
+	gpmc_onenand_data = devm_kzalloc(&pdev->dev, sizeof(*gpmc_onenand_data),
+					 GFP_KERNEL);
+	if (!gpmc_onenand_data)
+		return -ENOMEM;
+
+	gpmc_onenand_data->cs = val;
+	gpmc_onenand_data->of_node = child;
+	gpmc_onenand_data->dma_channel = -1;
+
+	if (!of_property_read_u32(child, "dma-channel", &val))
+		gpmc_onenand_data->dma_channel = val;
+
+	gpmc_onenand_init(gpmc_onenand_data);
+
+	return 0;
+}
+#else
+static int gpmc_probe_onenand_child(struct platform_device *pdev,
+				    struct device_node *child)
+{
+	return 0;
+}
+#endif
+
+/**
+ * gpmc_probe_generic_child - configures the gpmc for a child device
+ * @pdev:	pointer to gpmc platform device
+ * @child:	pointer to device-tree node for child device
+ *
+ * Allocates and configures a GPMC chip-select for a child device.
+ * Returns 0 on success and appropriate negative error code on failure.
+ */
+static int gpmc_probe_generic_child(struct platform_device *pdev,
+				struct device_node *child)
+{
+	struct gpmc_settings gpmc_s;
+	struct gpmc_timings gpmc_t;
+	struct resource res;
+	unsigned long base;
+	const char *name;
+	int ret, cs;
+	u32 val;
+
+	if (of_property_read_u32(child, "reg", &cs) < 0) {
+		dev_err(&pdev->dev, "%s has no 'reg' property\n",
+			child->full_name);
+		return -ENODEV;
+	}
+
+	if (of_address_to_resource(child, 0, &res) < 0) {
+		dev_err(&pdev->dev, "%s has malformed 'reg' property\n",
+			child->full_name);
+		return -ENODEV;
+	}
+
+	/*
+	 * Check if we have multiple instances of the same device
+	 * on a single chip select. If so, use the already initialized
+	 * timings.
+	 */
+	name = gpmc_cs_get_name(cs);
+	if (name && child->name && of_node_cmp(child->name, name) == 0)
+			goto no_timings;
+
+	ret = gpmc_cs_request(cs, resource_size(&res), &base);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "cannot request GPMC CS %d\n", cs);
+		return ret;
+	}
+	gpmc_cs_set_name(cs, child->name);
+
+	gpmc_read_settings_dt(child, &gpmc_s);
+	gpmc_read_timings_dt(child, &gpmc_t);
+
+	/*
+	 * For some GPMC devices we still need to rely on the bootloader
+	 * timings because the devices can be connected via FPGA.
+	 * REVISIT: Add timing support from slls644g.pdf.
+	 */
+	if (!gpmc_t.cs_rd_off) {
+		WARN(1, "enable GPMC debug to configure .dts timings for CS%i\n",
+			cs);
+		gpmc_cs_show_timings(cs,
+				     "please add GPMC bootloader timings to .dts");
+		goto no_timings;
+	}
+
+	/* CS must be disabled while making changes to gpmc configuration */
+	gpmc_cs_disable_mem(cs);
+
+	/*
+	 * FIXME: gpmc_cs_request() will map the CS to an arbitary
+	 * location in the gpmc address space. When booting with
+	 * device-tree we want the NOR flash to be mapped to the
+	 * location specified in the device-tree blob. So remap the
+	 * CS to this location. Once DT migration is complete should
+	 * just make gpmc_cs_request() map a specific address.
+	 */
+	ret = gpmc_cs_remap(cs, res.start);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "cannot remap GPMC CS %d to %pa\n",
+			cs, &res.start);
+		goto err;
+	}
+
+	ret = of_property_read_u32(child, "bank-width", &gpmc_s.device_width);
+	if (ret < 0)
+		goto err;
+
+	ret = gpmc_cs_program_settings(cs, &gpmc_s);
+	if (ret < 0)
+		goto err;
+
+	ret = gpmc_cs_set_timings(cs, &gpmc_t);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to set gpmc timings for: %s\n",
+			child->name);
+		goto err;
+	}
+
+	/* Clear limited address i.e. enable A26-A11 */
+	val = gpmc_read_reg(GPMC_CONFIG);
+	val &= ~GPMC_CONFIG_LIMITEDADDRESS;
+	gpmc_write_reg(GPMC_CONFIG, val);
+
+	/* Enable CS region */
+	gpmc_cs_enable_mem(cs);
+
+no_timings:
+	if (of_platform_device_create(child, NULL, &pdev->dev))
+		return 0;
+
+	dev_err(&pdev->dev, "failed to create gpmc child %s\n", child->name);
+	ret = -ENODEV;
+
+err:
+	gpmc_cs_free(cs);
+
+	return ret;
+}
+
+static int gpmc_probe_dt(struct platform_device *pdev)
+{
+	int ret;
+	struct device_node *child;
+	const struct of_device_id *of_id =
+		of_match_device(gpmc_dt_ids, &pdev->dev);
+
+	if (!of_id)
+		return 0;
+
+	ret = of_property_read_u32(pdev->dev.of_node, "gpmc,num-cs",
+				   &gpmc_cs_num);
+	if (ret < 0) {
+		pr_err("%s: number of chip-selects not defined\n", __func__);
+		return ret;
+	} else if (gpmc_cs_num < 1) {
+		pr_err("%s: all chip-selects are disabled\n", __func__);
+		return -EINVAL;
+	} else if (gpmc_cs_num > GPMC_CS_NUM) {
+		pr_err("%s: number of supported chip-selects cannot be > %d\n",
+					 __func__, GPMC_CS_NUM);
+		return -EINVAL;
+	}
+
+	ret = of_property_read_u32(pdev->dev.of_node, "gpmc,num-waitpins",
+				   &gpmc_nr_waitpins);
+	if (ret < 0) {
+		pr_err("%s: number of wait pins not found!\n", __func__);
+		return ret;
+	}
+
+	for_each_available_child_of_node(pdev->dev.of_node, child) {
+
+		if (!child->name)
+			continue;
+
+		if (of_node_cmp(child->name, "nand") == 0)
+			ret = gpmc_probe_nand_child(pdev, child);
+		else if (of_node_cmp(child->name, "onenand") == 0)
+			ret = gpmc_probe_onenand_child(pdev, child);
+		else if (of_node_cmp(child->name, "ethernet") == 0 ||
+			 of_node_cmp(child->name, "nor") == 0 ||
+			 of_node_cmp(child->name, "uart") == 0)
+			ret = gpmc_probe_generic_child(pdev, child);
+
+		if (WARN(ret < 0, "%s: probing gpmc child %s failed\n",
+			 __func__, child->full_name))
+			of_node_put(child);
+	}
+
+	return 0;
+}
+#else
+static int gpmc_probe_dt(struct platform_device *pdev)
+{
+	return 0;
+}
+#endif
+
+static int gpmc_probe(struct platform_device *pdev)
+{
+	int rc;
+	u32 l;
+	struct resource *res;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (res == NULL)
+		return -ENOENT;
+
+	phys_base = res->start;
+	mem_size = resource_size(res);
+
+	gpmc_base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(gpmc_base))
+		return PTR_ERR(gpmc_base);
+
+	res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+	if (res == NULL)
+		dev_warn(&pdev->dev, "Failed to get resource: irq\n");
+	else
+		gpmc_irq = res->start;
+
+	gpmc_l3_clk = devm_clk_get(&pdev->dev, "fck");
+	if (IS_ERR(gpmc_l3_clk)) {
+		dev_err(&pdev->dev, "Failed to get GPMC fck\n");
+		gpmc_irq = 0;
+		return PTR_ERR(gpmc_l3_clk);
+	}
+
+	if (!clk_get_rate(gpmc_l3_clk)) {
+		dev_err(&pdev->dev, "Invalid GPMC fck clock rate\n");
+		return -EINVAL;
+	}
+
+	pm_runtime_enable(&pdev->dev);
+	pm_runtime_get_sync(&pdev->dev);
+
+	gpmc_dev = &pdev->dev;
+
+	l = gpmc_read_reg(GPMC_REVISION);
+
+	/*
+	 * FIXME: Once device-tree migration is complete the below flags
+	 * should be populated based upon the device-tree compatible
+	 * string. For now just use the IP revision. OMAP3+ devices have
+	 * the wr_access and wr_data_mux_bus register fields. OMAP4+
+	 * devices support the addr-addr-data multiplex protocol.
+	 *
+	 * GPMC IP revisions:
+	 * - OMAP24xx			= 2.0
+	 * - OMAP3xxx			= 5.0
+	 * - OMAP44xx/54xx/AM335x	= 6.0
+	 */
+	if (GPMC_REVISION_MAJOR(l) > 0x4)
+		gpmc_capability = GPMC_HAS_WR_ACCESS | GPMC_HAS_WR_DATA_MUX_BUS;
+	if (GPMC_REVISION_MAJOR(l) > 0x5)
+		gpmc_capability |= GPMC_HAS_MUX_AAD;
+	dev_info(gpmc_dev, "GPMC revision %d.%d\n", GPMC_REVISION_MAJOR(l),
+		 GPMC_REVISION_MINOR(l));
+
+	gpmc_mem_init();
+
+	if (gpmc_setup_irq() < 0)
+		dev_warn(gpmc_dev, "gpmc_setup_irq failed\n");
+
+	if (!pdev->dev.of_node) {
+		gpmc_cs_num	 = GPMC_CS_NUM;
+		gpmc_nr_waitpins = GPMC_NR_WAITPINS;
+	}
+
+	rc = gpmc_probe_dt(pdev);
+	if (rc < 0) {
+		pm_runtime_put_sync(&pdev->dev);
+		dev_err(gpmc_dev, "failed to probe DT parameters\n");
+		return rc;
+	}
+
+	return 0;
+}
+
+static int gpmc_remove(struct platform_device *pdev)
+{
+	gpmc_free_irq();
+	gpmc_mem_exit();
+	pm_runtime_put_sync(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
+	gpmc_dev = NULL;
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int gpmc_suspend(struct device *dev)
+{
+	omap3_gpmc_save_context();
+	pm_runtime_put_sync(dev);
+	return 0;
+}
+
+static int gpmc_resume(struct device *dev)
+{
+	pm_runtime_get_sync(dev);
+	omap3_gpmc_restore_context();
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(gpmc_pm_ops, gpmc_suspend, gpmc_resume);
+
+static struct platform_driver gpmc_driver = {
+	.probe		= gpmc_probe,
+	.remove		= gpmc_remove,
+	.driver		= {
+		.name	= DEVICE_NAME,
+		.owner	= THIS_MODULE,
+		.of_match_table = of_match_ptr(gpmc_dt_ids),
+		.pm	= &gpmc_pm_ops,
+	},
+};
+
+static __init int gpmc_init(void)
+{
+	return platform_driver_register(&gpmc_driver);
+}
+
+static __exit void gpmc_exit(void)
+{
+	platform_driver_unregister(&gpmc_driver);
+
+}
+
+postcore_initcall(gpmc_init);
+module_exit(gpmc_exit);
+
+static irqreturn_t gpmc_handle_irq(int irq, void *dev)
+{
+	int i;
+	u32 regval;
+
+	regval = gpmc_read_reg(GPMC_IRQSTATUS);
+
+	if (!regval)
+		return IRQ_NONE;
+
+	for (i = 0; i < GPMC_NR_IRQ; i++)
+		if (regval & gpmc_client_irq[i].bitmask)
+			generic_handle_irq(gpmc_client_irq[i].irq);
+
+	gpmc_write_reg(GPMC_IRQSTATUS, regval);
+
+	return IRQ_HANDLED;
+}
+
+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);
+		}
+	}
+}