arch/arm/mach-omap2/gpmc-onenand.c - kernel/bruno - Git at Google

 /*
  * linux/arch/arm/mach-omap2/gpmc-onenand.c
  *
  * Copyright (C) 2006 - 2009 Nokia Corporation
  * Contacts:	Juha Yrjola
  *		Tony Lindgren
  *
  * 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.
  */

 #include <linux/string.h>
 #include <linux/kernel.h>
 #include <linux/platform_device.h>
 #include <linux/mtd/onenand_regs.h>
 #include <linux/io.h>
 #include <linux/omap-gpmc.h>
 #include <linux/platform_data/mtd-onenand-omap2.h>
 #include <linux/err.h>

 #include <asm/mach/flash.h>

 #include "soc.h"

 #define	ONENAND_IO_SIZE	SZ_128K

 #define	ONENAND_FLAG_SYNCREAD	(1 << 0)
 #define	ONENAND_FLAG_SYNCWRITE	(1 << 1)
 #define	ONENAND_FLAG_HF		(1 << 2)
 #define	ONENAND_FLAG_VHF	(1 << 3)

 static unsigned onenand_flags;
 static unsigned latency;

 static struct omap_onenand_platform_data *gpmc_onenand_data;

 static struct resource gpmc_onenand_resource = {
 	.flags		= IORESOURCE_MEM,
 };

 static struct platform_device gpmc_onenand_device = {
 	.name		= "omap2-onenand",
 	.id		= -1,
 	.num_resources	= 1,
 	.resource	= &gpmc_onenand_resource,
 };

 static struct gpmc_settings onenand_async = {
 	.device_width	= GPMC_DEVWIDTH_16BIT,
 	.mux_add_data	= GPMC_MUX_AD,
 };

 static struct gpmc_settings onenand_sync = {
 	.burst_read	= true,
 	.burst_wrap	= true,
 	.burst_len	= GPMC_BURST_16,
 	.device_width	= GPMC_DEVWIDTH_16BIT,
 	.mux_add_data	= GPMC_MUX_AD,
 	.wait_pin	= 0,
 };

 static void omap2_onenand_calc_async_timings(struct gpmc_timings *t)
 {
 	struct gpmc_device_timings dev_t;
 	const int t_cer = 15;
 	const int t_avdp = 12;
 	const int t_aavdh = 7;
 	const int t_ce = 76;
 	const int t_aa = 76;
 	const int t_oe = 20;
 	const int t_cez = 20; /* max of t_cez, t_oez */
 	const int t_wpl = 40;
 	const int t_wph = 30;

 	memset(&dev_t, 0, sizeof(dev_t));

 	dev_t.t_avdp_r = max_t(int, t_avdp, t_cer) * 1000;
 	dev_t.t_avdp_w = dev_t.t_avdp_r;
 	dev_t.t_aavdh = t_aavdh * 1000;
 	dev_t.t_aa = t_aa * 1000;
 	dev_t.t_ce = t_ce * 1000;
 	dev_t.t_oe = t_oe * 1000;
 	dev_t.t_cez_r = t_cez * 1000;
 	dev_t.t_cez_w = dev_t.t_cez_r;
 	dev_t.t_wpl = t_wpl * 1000;
 	dev_t.t_wph = t_wph * 1000;

 	gpmc_calc_timings(t, &onenand_async, &dev_t);
 }

 static void omap2_onenand_set_async_mode(void __iomem *onenand_base)
 {
 	u32 reg;

 	/* Ensure sync read and sync write are disabled */
 	reg = readw(onenand_base + ONENAND_REG_SYS_CFG1);
 	reg &= ~ONENAND_SYS_CFG1_SYNC_READ & ~ONENAND_SYS_CFG1_SYNC_WRITE;
 	writew(reg, onenand_base + ONENAND_REG_SYS_CFG1);
 }

 static void set_onenand_cfg(void __iomem *onenand_base)
 {
 	u32 reg = ONENAND_SYS_CFG1_RDY | ONENAND_SYS_CFG1_INT;

 	reg |=	(latency << ONENAND_SYS_CFG1_BRL_SHIFT) |
 		ONENAND_SYS_CFG1_BL_16;
 	if (onenand_flags & ONENAND_FLAG_SYNCREAD)
 		reg |= ONENAND_SYS_CFG1_SYNC_READ;
 	else
 		reg &= ~ONENAND_SYS_CFG1_SYNC_READ;
 	if (onenand_flags & ONENAND_FLAG_SYNCWRITE)
 		reg |= ONENAND_SYS_CFG1_SYNC_WRITE;
 	else
 		reg &= ~ONENAND_SYS_CFG1_SYNC_WRITE;
 	if (onenand_flags & ONENAND_FLAG_HF)
 		reg |= ONENAND_SYS_CFG1_HF;
 	else
 		reg &= ~ONENAND_SYS_CFG1_HF;
 	if (onenand_flags & ONENAND_FLAG_VHF)
 		reg |= ONENAND_SYS_CFG1_VHF;
 	else
 		reg &= ~ONENAND_SYS_CFG1_VHF;

 	writew(reg, onenand_base + ONENAND_REG_SYS_CFG1);
 }

 static int omap2_onenand_get_freq(struct omap_onenand_platform_data *cfg,
 				  void __iomem *onenand_base)
 {
 	u16 ver = readw(onenand_base + ONENAND_REG_VERSION_ID);
 	int freq;

 	switch ((ver >> 4) & 0xf) {
 	case 0:
 		freq = 40;
 		break;
 	case 1:
 		freq = 54;
 		break;
 	case 2:
 		freq = 66;
 		break;
 	case 3:
 		freq = 83;
 		break;
 	case 4:
 		freq = 104;
 		break;
 	default:
 		pr_err("onenand rate not detected, bad GPMC async timings?\n");
 		freq = 0;
 	}

 	return freq;
 }

 static void omap2_onenand_calc_sync_timings(struct gpmc_timings *t,
 					    unsigned int flags,
 					    int freq)
 {
 	struct gpmc_device_timings dev_t;
 	const int t_cer  = 15;
 	const int t_avdp = 12;
 	const int t_cez  = 20; /* max of t_cez, t_oez */
 	const int t_wpl  = 40;
 	const int t_wph  = 30;
 	int min_gpmc_clk_period, t_ces, t_avds, t_avdh, t_ach, t_aavdh, t_rdyo;
 	int div, gpmc_clk_ns;

 	if (flags & ONENAND_SYNC_READ)
 		onenand_flags = ONENAND_FLAG_SYNCREAD;
 	else if (flags & ONENAND_SYNC_READWRITE)
 		onenand_flags = ONENAND_FLAG_SYNCREAD | ONENAND_FLAG_SYNCWRITE;

 	switch (freq) {
 	case 104:
 		min_gpmc_clk_period = 9600; /* 104 MHz */
 		t_ces   = 3;
 		t_avds  = 4;
 		t_avdh  = 2;
 		t_ach   = 3;
 		t_aavdh = 6;
 		t_rdyo  = 6;
 		break;
 	case 83:
 		min_gpmc_clk_period = 12000; /* 83 MHz */
 		t_ces   = 5;
 		t_avds  = 4;
 		t_avdh  = 2;
 		t_ach   = 6;
 		t_aavdh = 6;
 		t_rdyo  = 9;
 		break;
 	case 66:
 		min_gpmc_clk_period = 15000; /* 66 MHz */
 		t_ces   = 6;
 		t_avds  = 5;
 		t_avdh  = 2;
 		t_ach   = 6;
 		t_aavdh = 6;
 		t_rdyo  = 11;
 		break;
 	default:
 		min_gpmc_clk_period = 18500; /* 54 MHz */
 		t_ces   = 7;
 		t_avds  = 7;
 		t_avdh  = 7;
 		t_ach   = 9;
 		t_aavdh = 7;
 		t_rdyo  = 15;
 		onenand_flags &= ~ONENAND_FLAG_SYNCWRITE;
 		break;
 	}

 	div = gpmc_calc_divider(min_gpmc_clk_period);
 	gpmc_clk_ns = gpmc_ticks_to_ns(div);
 	if (gpmc_clk_ns < 15) /* >66MHz */
 		onenand_flags |= ONENAND_FLAG_HF;
 	else
 		onenand_flags &= ~ONENAND_FLAG_HF;
 	if (gpmc_clk_ns < 12) /* >83MHz */
 		onenand_flags |= ONENAND_FLAG_VHF;
 	else
 		onenand_flags &= ~ONENAND_FLAG_VHF;
 	if (onenand_flags & ONENAND_FLAG_VHF)
 		latency = 8;
 	else if (onenand_flags & ONENAND_FLAG_HF)
 		latency = 6;
 	else if (gpmc_clk_ns >= 25) /* 40 MHz*/
 		latency = 3;
 	else
 		latency = 4;

 	/* Set synchronous read timings */
 	memset(&dev_t, 0, sizeof(dev_t));

 	if (onenand_flags & ONENAND_FLAG_SYNCREAD)
 		onenand_sync.sync_read = true;
 	if (onenand_flags & ONENAND_FLAG_SYNCWRITE) {
 		onenand_sync.sync_write = true;
 		onenand_sync.burst_write = true;
 	} else {
 		dev_t.t_avdp_w = max(t_avdp, t_cer) * 1000;
 		dev_t.t_wpl = t_wpl * 1000;
 		dev_t.t_wph = t_wph * 1000;
 		dev_t.t_aavdh = t_aavdh * 1000;
 	}
 	dev_t.ce_xdelay = true;
 	dev_t.avd_xdelay = true;
 	dev_t.oe_xdelay = true;
 	dev_t.we_xdelay = true;
 	dev_t.clk = min_gpmc_clk_period;
 	dev_t.t_bacc = dev_t.clk;
 	dev_t.t_ces = t_ces * 1000;
 	dev_t.t_avds = t_avds * 1000;
 	dev_t.t_avdh = t_avdh * 1000;
 	dev_t.t_ach = t_ach * 1000;
 	dev_t.cyc_iaa = (latency + 1);
 	dev_t.t_cez_r = t_cez * 1000;
 	dev_t.t_cez_w = dev_t.t_cez_r;
 	dev_t.cyc_aavdh_oe = 1;
 	dev_t.t_rdyo = t_rdyo * 1000 + min_gpmc_clk_period;

 	gpmc_calc_timings(t, &onenand_sync, &dev_t);
 }

 static int omap2_onenand_setup_async(void __iomem *onenand_base)
 {
 	struct gpmc_timings t;
 	int ret;

 	/*
 	 * Note that we need to keep sync_write set for the call to
 	 * omap2_onenand_set_async_mode() to work to detect the onenand
 	 * supported clock rate for the sync timings.
 	 */
 	if (gpmc_onenand_data->of_node) {
 		gpmc_read_settings_dt(gpmc_onenand_data->of_node,
 				      &onenand_async);
 		if (onenand_async.sync_read || onenand_async.sync_write) {
 			if (onenand_async.sync_write)
 				gpmc_onenand_data->flags |=
 					ONENAND_SYNC_READWRITE;
 			else
 				gpmc_onenand_data->flags |= ONENAND_SYNC_READ;
 			onenand_async.sync_read = false;
 		}
 	}

 	onenand_async.sync_write = true;
 	omap2_onenand_calc_async_timings(&t);

 	ret = gpmc_cs_program_settings(gpmc_onenand_data->cs, &onenand_async);
 	if (ret < 0)
 		return ret;

 	ret = gpmc_cs_set_timings(gpmc_onenand_data->cs, &t, &onenand_async);
 	if (ret < 0)
 		return ret;

 	omap2_onenand_set_async_mode(onenand_base);

 	return 0;
 }

 static int omap2_onenand_setup_sync(void __iomem *onenand_base, int *freq_ptr)
 {
 	int ret, freq = *freq_ptr;
 	struct gpmc_timings t;

 	if (!freq) {
 		/* Very first call freq is not known */
 		freq = omap2_onenand_get_freq(gpmc_onenand_data, onenand_base);
 		if (!freq)
 			return -ENODEV;
 		set_onenand_cfg(onenand_base);
 	}

 	if (gpmc_onenand_data->of_node) {
 		gpmc_read_settings_dt(gpmc_onenand_data->of_node,
 				      &onenand_sync);
 	} else {
 		/*
 		 * FIXME: Appears to be legacy code from initial ONENAND commit.
 		 * Unclear what boards this is for and if this can be removed.
 		 */
 		if (!cpu_is_omap34xx())
 			onenand_sync.wait_on_read = true;
 	}

 	omap2_onenand_calc_sync_timings(&t, gpmc_onenand_data->flags, freq);

 	ret = gpmc_cs_program_settings(gpmc_onenand_data->cs, &onenand_sync);
 	if (ret < 0)
 		return ret;

 	ret = gpmc_cs_set_timings(gpmc_onenand_data->cs, &t, &onenand_sync);
 	if (ret < 0)
 		return ret;

 	set_onenand_cfg(onenand_base);

 	*freq_ptr = freq;

 	return 0;
 }

 static int gpmc_onenand_setup(void __iomem *onenand_base, int *freq_ptr)
 {
 	struct device *dev = &gpmc_onenand_device.dev;
 	unsigned l = ONENAND_SYNC_READ | ONENAND_SYNC_READWRITE;
 	int ret;

 	ret = omap2_onenand_setup_async(onenand_base);
 	if (ret) {
 		dev_err(dev, "unable to set to async mode\n");
 		return ret;
 	}

 	if (!(gpmc_onenand_data->flags & l))
 		return 0;

 	ret = omap2_onenand_setup_sync(onenand_base, freq_ptr);
 	if (ret)
 		dev_err(dev, "unable to set to sync mode\n");
 	return ret;
 }

 void gpmc_onenand_init(struct omap_onenand_platform_data *_onenand_data)
 {
 	int err;
 	struct device *dev = &gpmc_onenand_device.dev;

 	gpmc_onenand_data = _onenand_data;
 	gpmc_onenand_data->onenand_setup = gpmc_onenand_setup;
 	gpmc_onenand_device.dev.platform_data = gpmc_onenand_data;

 	if (cpu_is_omap24xx() &&
 			(gpmc_onenand_data->flags & ONENAND_SYNC_READWRITE)) {
 		dev_warn(dev, "OneNAND using only SYNC_READ on 24xx\n");
 		gpmc_onenand_data->flags &= ~ONENAND_SYNC_READWRITE;
 		gpmc_onenand_data->flags |= ONENAND_SYNC_READ;
 	}

 	if (cpu_is_omap34xx())
 		gpmc_onenand_data->flags |= ONENAND_IN_OMAP34XX;
 	else
 		gpmc_onenand_data->flags &= ~ONENAND_IN_OMAP34XX;

 	err = gpmc_cs_request(gpmc_onenand_data->cs, ONENAND_IO_SIZE,
 				(unsigned long *)&gpmc_onenand_resource.start);
 	if (err < 0) {
 		dev_err(dev, "Cannot request GPMC CS %d, error %d\n",
 			gpmc_onenand_data->cs, err);
 		return;
 	}

 	gpmc_onenand_resource.end = gpmc_onenand_resource.start +
 							ONENAND_IO_SIZE - 1;

 	if (platform_device_register(&gpmc_onenand_device) < 0) {
 		dev_err(dev, "Unable to register OneNAND device\n");
 		gpmc_cs_free(gpmc_onenand_data->cs);
 		return;
 	}
 }
	/*
	* linux/arch/arm/mach-omap2/gpmc-onenand.c
	*
	* Copyright (C) 2006 - 2009 Nokia Corporation
	* Contacts: Juha Yrjola
	* Tony Lindgren
	*
	* 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.
	*/

	#include <linux/string.h>
	#include <linux/kernel.h>
	#include <linux/platform_device.h>
	#include <linux/mtd/onenand_regs.h>
	#include <linux/io.h>
	#include <linux/omap-gpmc.h>
	#include <linux/platform_data/mtd-onenand-omap2.h>
	#include <linux/err.h>

	#include <asm/mach/flash.h>

	#include "soc.h"

	#define ONENAND_IO_SIZE SZ_128K

	#define ONENAND_FLAG_SYNCREAD (1 << 0)
	#define ONENAND_FLAG_SYNCWRITE (1 << 1)
	#define ONENAND_FLAG_HF (1 << 2)
	#define ONENAND_FLAG_VHF (1 << 3)

	static unsigned onenand_flags;
	static unsigned latency;

	static struct omap_onenand_platform_data *gpmc_onenand_data;

	static struct resource gpmc_onenand_resource = {
	.flags = IORESOURCE_MEM,
	};

	static struct platform_device gpmc_onenand_device = {
	.name = "omap2-onenand",
	.id = -1,
	.num_resources = 1,
	.resource = &gpmc_onenand_resource,
	};

	static struct gpmc_settings onenand_async = {
	.device_width = GPMC_DEVWIDTH_16BIT,
	.mux_add_data = GPMC_MUX_AD,
	};

	static struct gpmc_settings onenand_sync = {
	.burst_read = true,
	.burst_wrap = true,
	.burst_len = GPMC_BURST_16,
	.device_width = GPMC_DEVWIDTH_16BIT,
	.mux_add_data = GPMC_MUX_AD,
	.wait_pin = 0,
	};

	static void omap2_onenand_calc_async_timings(struct gpmc_timings *t)
	{
	struct gpmc_device_timings dev_t;
	const int t_cer = 15;
	const int t_avdp = 12;
	const int t_aavdh = 7;
	const int t_ce = 76;
	const int t_aa = 76;
	const int t_oe = 20;
	const int t_cez = 20; /* max of t_cez, t_oez */
	const int t_wpl = 40;
	const int t_wph = 30;

	memset(&dev_t, 0, sizeof(dev_t));

	dev_t.t_avdp_r = max_t(int, t_avdp, t_cer) * 1000;
	dev_t.t_avdp_w = dev_t.t_avdp_r;
	dev_t.t_aavdh = t_aavdh * 1000;
	dev_t.t_aa = t_aa * 1000;
	dev_t.t_ce = t_ce * 1000;
	dev_t.t_oe = t_oe * 1000;
	dev_t.t_cez_r = t_cez * 1000;
	dev_t.t_cez_w = dev_t.t_cez_r;
	dev_t.t_wpl = t_wpl * 1000;
	dev_t.t_wph = t_wph * 1000;

	gpmc_calc_timings(t, &onenand_async, &dev_t);
	}

	static void omap2_onenand_set_async_mode(void __iomem *onenand_base)
	{
	u32 reg;

	/* Ensure sync read and sync write are disabled */
	reg = readw(onenand_base + ONENAND_REG_SYS_CFG1);
	reg &= ~ONENAND_SYS_CFG1_SYNC_READ & ~ONENAND_SYS_CFG1_SYNC_WRITE;
	writew(reg, onenand_base + ONENAND_REG_SYS_CFG1);
	}

	static void set_onenand_cfg(void __iomem *onenand_base)
	{
	u32 reg = ONENAND_SYS_CFG1_RDY \| ONENAND_SYS_CFG1_INT;

	reg \|= (latency << ONENAND_SYS_CFG1_BRL_SHIFT) \|
	ONENAND_SYS_CFG1_BL_16;
	if (onenand_flags & ONENAND_FLAG_SYNCREAD)
	reg \|= ONENAND_SYS_CFG1_SYNC_READ;
	else
	reg &= ~ONENAND_SYS_CFG1_SYNC_READ;
	if (onenand_flags & ONENAND_FLAG_SYNCWRITE)
	reg \|= ONENAND_SYS_CFG1_SYNC_WRITE;
	else
	reg &= ~ONENAND_SYS_CFG1_SYNC_WRITE;
	if (onenand_flags & ONENAND_FLAG_HF)
	reg \|= ONENAND_SYS_CFG1_HF;
	else
	reg &= ~ONENAND_SYS_CFG1_HF;
	if (onenand_flags & ONENAND_FLAG_VHF)
	reg \|= ONENAND_SYS_CFG1_VHF;
	else
	reg &= ~ONENAND_SYS_CFG1_VHF;

	writew(reg, onenand_base + ONENAND_REG_SYS_CFG1);
	}

	static int omap2_onenand_get_freq(struct omap_onenand_platform_data *cfg,
	void __iomem *onenand_base)
	{
	u16 ver = readw(onenand_base + ONENAND_REG_VERSION_ID);
	int freq;

	switch ((ver >> 4) & 0xf) {
	case 0:
	freq = 40;
	break;
	case 1:
	freq = 54;
	break;
	case 2:
	freq = 66;
	break;
	case 3:
	freq = 83;
	break;
	case 4:
	freq = 104;
	break;
	default:
	pr_err("onenand rate not detected, bad GPMC async timings?\n");
	freq = 0;
	}

	return freq;
	}

	static void omap2_onenand_calc_sync_timings(struct gpmc_timings *t,
	unsigned int flags,
	int freq)
	{
	struct gpmc_device_timings dev_t;
	const int t_cer = 15;
	const int t_avdp = 12;
	const int t_cez = 20; /* max of t_cez, t_oez */
	const int t_wpl = 40;
	const int t_wph = 30;
	int min_gpmc_clk_period, t_ces, t_avds, t_avdh, t_ach, t_aavdh, t_rdyo;
	int div, gpmc_clk_ns;

	if (flags & ONENAND_SYNC_READ)
	onenand_flags = ONENAND_FLAG_SYNCREAD;
	else if (flags & ONENAND_SYNC_READWRITE)
	onenand_flags = ONENAND_FLAG_SYNCREAD \| ONENAND_FLAG_SYNCWRITE;

	switch (freq) {
	case 104:
	min_gpmc_clk_period = 9600; /* 104 MHz */
	t_ces = 3;
	t_avds = 4;
	t_avdh = 2;
	t_ach = 3;
	t_aavdh = 6;
	t_rdyo = 6;
	break;
	case 83:
	min_gpmc_clk_period = 12000; /* 83 MHz */
	t_ces = 5;
	t_avds = 4;
	t_avdh = 2;
	t_ach = 6;
	t_aavdh = 6;
	t_rdyo = 9;
	break;
	case 66:
	min_gpmc_clk_period = 15000; /* 66 MHz */
	t_ces = 6;
	t_avds = 5;
	t_avdh = 2;
	t_ach = 6;
	t_aavdh = 6;
	t_rdyo = 11;
	break;
	default:
	min_gpmc_clk_period = 18500; /* 54 MHz */
	t_ces = 7;
	t_avds = 7;
	t_avdh = 7;
	t_ach = 9;
	t_aavdh = 7;
	t_rdyo = 15;
	onenand_flags &= ~ONENAND_FLAG_SYNCWRITE;
	break;
	}

	div = gpmc_calc_divider(min_gpmc_clk_period);
	gpmc_clk_ns = gpmc_ticks_to_ns(div);
	if (gpmc_clk_ns < 15) /* >66MHz */
	onenand_flags \|= ONENAND_FLAG_HF;
	else
	onenand_flags &= ~ONENAND_FLAG_HF;
	if (gpmc_clk_ns < 12) /* >83MHz */
	onenand_flags \|= ONENAND_FLAG_VHF;
	else
	onenand_flags &= ~ONENAND_FLAG_VHF;
	if (onenand_flags & ONENAND_FLAG_VHF)
	latency = 8;
	else if (onenand_flags & ONENAND_FLAG_HF)
	latency = 6;
	else if (gpmc_clk_ns >= 25) /* 40 MHz*/
	latency = 3;
	else
	latency = 4;

	/* Set synchronous read timings */
	memset(&dev_t, 0, sizeof(dev_t));

	if (onenand_flags & ONENAND_FLAG_SYNCREAD)
	onenand_sync.sync_read = true;
	if (onenand_flags & ONENAND_FLAG_SYNCWRITE) {
	onenand_sync.sync_write = true;
	onenand_sync.burst_write = true;
	} else {
	dev_t.t_avdp_w = max(t_avdp, t_cer) * 1000;
	dev_t.t_wpl = t_wpl * 1000;
	dev_t.t_wph = t_wph * 1000;
	dev_t.t_aavdh = t_aavdh * 1000;
	}
	dev_t.ce_xdelay = true;
	dev_t.avd_xdelay = true;
	dev_t.oe_xdelay = true;
	dev_t.we_xdelay = true;
	dev_t.clk = min_gpmc_clk_period;
	dev_t.t_bacc = dev_t.clk;
	dev_t.t_ces = t_ces * 1000;
	dev_t.t_avds = t_avds * 1000;
	dev_t.t_avdh = t_avdh * 1000;
	dev_t.t_ach = t_ach * 1000;
	dev_t.cyc_iaa = (latency + 1);
	dev_t.t_cez_r = t_cez * 1000;
	dev_t.t_cez_w = dev_t.t_cez_r;
	dev_t.cyc_aavdh_oe = 1;
	dev_t.t_rdyo = t_rdyo * 1000 + min_gpmc_clk_period;

	gpmc_calc_timings(t, &onenand_sync, &dev_t);
	}

	static int omap2_onenand_setup_async(void __iomem *onenand_base)
	{
	struct gpmc_timings t;
	int ret;

	/*
	* Note that we need to keep sync_write set for the call to
	* omap2_onenand_set_async_mode() to work to detect the onenand
	* supported clock rate for the sync timings.
	*/
	if (gpmc_onenand_data->of_node) {
	gpmc_read_settings_dt(gpmc_onenand_data->of_node,
	&onenand_async);
	if (onenand_async.sync_read \|\| onenand_async.sync_write) {
	if (onenand_async.sync_write)
	gpmc_onenand_data->flags \|=
	ONENAND_SYNC_READWRITE;
	else
	gpmc_onenand_data->flags \|= ONENAND_SYNC_READ;
	onenand_async.sync_read = false;
	}
	}

	onenand_async.sync_write = true;
	omap2_onenand_calc_async_timings(&t);

	ret = gpmc_cs_program_settings(gpmc_onenand_data->cs, &onenand_async);
	if (ret < 0)
	return ret;

	ret = gpmc_cs_set_timings(gpmc_onenand_data->cs, &t, &onenand_async);
	if (ret < 0)
	return ret;

	omap2_onenand_set_async_mode(onenand_base);

	return 0;
	}

	static int omap2_onenand_setup_sync(void __iomem onenand_base, int freq_ptr)
	{
	int ret, freq = *freq_ptr;
	struct gpmc_timings t;

	if (!freq) {
	/* Very first call freq is not known */
	freq = omap2_onenand_get_freq(gpmc_onenand_data, onenand_base);
	if (!freq)
	return -ENODEV;
	set_onenand_cfg(onenand_base);
	}

	if (gpmc_onenand_data->of_node) {
	gpmc_read_settings_dt(gpmc_onenand_data->of_node,
	&onenand_sync);
	} else {
	/*
	* FIXME: Appears to be legacy code from initial ONENAND commit.
	* Unclear what boards this is for and if this can be removed.
	*/
	if (!cpu_is_omap34xx())
	onenand_sync.wait_on_read = true;
	}

	omap2_onenand_calc_sync_timings(&t, gpmc_onenand_data->flags, freq);

	ret = gpmc_cs_program_settings(gpmc_onenand_data->cs, &onenand_sync);
	if (ret < 0)
	return ret;

	ret = gpmc_cs_set_timings(gpmc_onenand_data->cs, &t, &onenand_sync);
	if (ret < 0)
	return ret;

	set_onenand_cfg(onenand_base);

	*freq_ptr = freq;

	return 0;
	}

	static int gpmc_onenand_setup(void __iomem onenand_base, int freq_ptr)
	{
	struct device *dev = &gpmc_onenand_device.dev;
	unsigned l = ONENAND_SYNC_READ \| ONENAND_SYNC_READWRITE;
	int ret;

	ret = omap2_onenand_setup_async(onenand_base);
	if (ret) {
	dev_err(dev, "unable to set to async mode\n");
	return ret;
	}

	if (!(gpmc_onenand_data->flags & l))
	return 0;

	ret = omap2_onenand_setup_sync(onenand_base, freq_ptr);
	if (ret)
	dev_err(dev, "unable to set to sync mode\n");
	return ret;
	}

	void gpmc_onenand_init(struct omap_onenand_platform_data *_onenand_data)
	{
	int err;
	struct device *dev = &gpmc_onenand_device.dev;

	gpmc_onenand_data = _onenand_data;
	gpmc_onenand_data->onenand_setup = gpmc_onenand_setup;
	gpmc_onenand_device.dev.platform_data = gpmc_onenand_data;

	if (cpu_is_omap24xx() &&
	(gpmc_onenand_data->flags & ONENAND_SYNC_READWRITE)) {
	dev_warn(dev, "OneNAND using only SYNC_READ on 24xx\n");
	gpmc_onenand_data->flags &= ~ONENAND_SYNC_READWRITE;
	gpmc_onenand_data->flags \|= ONENAND_SYNC_READ;
	}

	if (cpu_is_omap34xx())
	gpmc_onenand_data->flags \|= ONENAND_IN_OMAP34XX;
	else
	gpmc_onenand_data->flags &= ~ONENAND_IN_OMAP34XX;

	err = gpmc_cs_request(gpmc_onenand_data->cs, ONENAND_IO_SIZE,
	(unsigned long *)&gpmc_onenand_resource.start);
	if (err < 0) {
	dev_err(dev, "Cannot request GPMC CS %d, error %d\n",
	gpmc_onenand_data->cs, err);
	return;
	}

	gpmc_onenand_resource.end = gpmc_onenand_resource.start +
	ONENAND_IO_SIZE - 1;

	if (platform_device_register(&gpmc_onenand_device) < 0) {
	dev_err(dev, "Unable to register OneNAND device\n");
	gpmc_cs_free(gpmc_onenand_data->cs);
	return;
	}
	}