drivers/ata/pata_at91.c - arm/linux-arm-legacy - Git at Google

 /*
  * PATA driver for AT91SAM9260 Static Memory Controller
  * with CompactFlash interface in True IDE mode
  *
  * Copyright (C) 2009 Matyukevich Sergey
  *               2011 Igor Plyatov
  *
  * Based on:
  *      * generic platform driver by Paul Mundt: drivers/ata/pata_platform.c
  *      * pata_at32 driver by Kristoffer Nyborg Gregertsen
  *      * at91_ide driver by Stanislaw Gruszka
  *
  * 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/kernel.h>
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/blkdev.h>
 #include <linux/gfp.h>
 #include <scsi/scsi_host.h>
 #include <linux/ata.h>
 #include <linux/clk.h>
 #include <linux/libata.h>
 #include <linux/platform_device.h>
 #include <linux/ata_platform.h>
 #include <linux/platform_data/atmel.h>

 #include <mach/at91sam9_smc.h>
 #include <asm/gpio.h>

 #define DRV_NAME		"pata_at91"
 #define DRV_VERSION		"0.3"

 #define CF_IDE_OFFSET		0x00c00000
 #define CF_ALT_IDE_OFFSET	0x00e00000
 #define CF_IDE_RES_SIZE		0x08
 #define CS_PULSE_MAXIMUM	319
 #define ER_SMC_CALC		1
 #define ER_SMC_RECALC		2

 struct at91_ide_info {
 	unsigned long mode;
 	unsigned int cs;
 	struct clk *mck;
 	void __iomem *ide_addr;
 	void __iomem *alt_addr;
 };

 /**
  * struct smc_range - range of valid values for SMC register.
  */
 struct smc_range {
 	int min;
 	int max;
 };

 /**
  * adjust_smc_value - adjust value for one of SMC registers.
  * @value: adjusted value
  * @range: array of SMC ranges with valid values
  * @size: SMC ranges array size
  *
  * This returns the difference between input and output value or negative
  * in case of invalid input value.
  * If negative returned, then output value = maximal possible from ranges.
  */
 static int adjust_smc_value(int *value, struct smc_range *range, int size)
 {
 	int maximum = (range + size - 1)->max;
 	int remainder;

 	do {
 		if (*value < range->min) {
 			remainder = range->min - *value;
 			*value = range->min; /* nearest valid value */
 			return remainder;
 		} else if ((range->min <= *value) && (*value <= range->max))
 			return 0;

 		range++;
 	} while (--size);
 	*value = maximum;

 	return -1; /* invalid value */
 }

 /**
  * calc_smc_vals - calculate SMC register values
  * @dev: ATA device
  * @setup: SMC_SETUP register value
  * @pulse: SMC_PULSE register value
  * @cycle: SMC_CYCLE register value
  *
  * This returns negative in case of invalid values for SMC registers:
  * -ER_SMC_RECALC - recalculation required for SMC values,
  * -ER_SMC_CALC - calculation failed (invalid input values).
  *
  * SMC use special coding scheme, see "Coding and Range of Timing
  * Parameters" table from AT91SAM9 datasheets.
  *
  *	SMC_SETUP = 128*setup[5] + setup[4:0]
  *	SMC_PULSE = 256*pulse[6] + pulse[5:0]
  *	SMC_CYCLE = 256*cycle[8:7] + cycle[6:0]
  */
 static int calc_smc_vals(struct device *dev,
 		int *setup, int *pulse, int *cycle, int *cs_pulse)
 {
 	int ret_val;
 	int err = 0;
 	struct smc_range range_setup[] = {	/* SMC_SETUP valid values */
 		{.min = 0,	.max = 31},	/* first  range */
 		{.min = 128,	.max = 159}	/* second range */
 	};
 	struct smc_range range_pulse[] = {	/* SMC_PULSE valid values */
 		{.min = 0,	.max = 63},	/* first  range */
 		{.min = 256,	.max = 319}	/* second range */
 	};
 	struct smc_range range_cycle[] = {	/* SMC_CYCLE valid values */
 		{.min = 0,	.max = 127},	/* first  range */
 		{.min = 256,	.max = 383},	/* second range */
 		{.min = 512,	.max = 639},	/* third  range */
 		{.min = 768,	.max = 895}	/* fourth range */
 	};

 	ret_val = adjust_smc_value(setup, range_setup, ARRAY_SIZE(range_setup));
 	if (ret_val < 0)
 		dev_warn(dev, "maximal SMC Setup value\n");
 	else
 		*cycle += ret_val;

 	ret_val = adjust_smc_value(pulse, range_pulse, ARRAY_SIZE(range_pulse));
 	if (ret_val < 0)
 		dev_warn(dev, "maximal SMC Pulse value\n");
 	else
 		*cycle += ret_val;

 	ret_val = adjust_smc_value(cycle, range_cycle, ARRAY_SIZE(range_cycle));
 	if (ret_val < 0)
 		dev_warn(dev, "maximal SMC Cycle value\n");

 	*cs_pulse = *cycle;
 	if (*cs_pulse > CS_PULSE_MAXIMUM) {
 		dev_err(dev, "unable to calculate valid SMC settings\n");
 		return -ER_SMC_CALC;
 	}

 	ret_val = adjust_smc_value(cs_pulse, range_pulse,
 					ARRAY_SIZE(range_pulse));
 	if (ret_val < 0) {
 		dev_warn(dev, "maximal SMC CS Pulse value\n");
 	} else if (ret_val != 0) {
 		*cycle = *cs_pulse;
 		dev_warn(dev, "SMC Cycle extended\n");
 		err = -ER_SMC_RECALC;
 	}

 	return err;
 }

 /**
  * to_smc_format - convert values into SMC format
  * @setup: SETUP value of SMC Setup Register
  * @pulse: PULSE value of SMC Pulse Register
  * @cycle: CYCLE value of SMC Cycle Register
  * @cs_pulse: NCS_PULSE value of SMC Pulse Register
  */
 static void to_smc_format(int *setup, int *pulse, int *cycle, int *cs_pulse)
 {
 	*setup = (*setup & 0x1f) | ((*setup & 0x80) >> 2);
 	*pulse = (*pulse & 0x3f) | ((*pulse & 0x100) >> 2);
 	*cycle = (*cycle & 0x7f) | ((*cycle & 0x300) >> 1);
 	*cs_pulse = (*cs_pulse & 0x3f) | ((*cs_pulse & 0x100) >> 2);
 }

 static unsigned long calc_mck_cycles(unsigned long ns, unsigned long mck_hz)
 {
 	unsigned long mul;

 	/*
 	* cycles = x [nsec] * f [Hz] / 10^9 [ns in sec] =
 	*     x * (f / 1_000_000_000) =
 	*     x * ((f * 65536) / 1_000_000_000) / 65536 =
 	*     x * (((f / 10_000) * 65536) / 100_000) / 65536 =
 	*/

 	mul = (mck_hz / 10000) << 16;
 	mul /= 100000;

 	return (ns * mul + 65536) >> 16;    /* rounding */
 }

 /**
  * set_smc_timing - SMC timings setup.
  * @dev: device
  * @info: AT91 IDE info
  * @ata: ATA timings
  *
  * Its assumed that write timings are same as read timings,
  * cs_setup = 0 and cs_pulse = cycle.
  */
 static void set_smc_timing(struct device *dev, struct ata_device *adev,
 		struct at91_ide_info *info, const struct ata_timing *ata)
 {
 	int ret = 0;
 	int use_iordy;
 	struct sam9_smc_config smc;
 	unsigned int t6z;         /* data tristate time in ns */
 	unsigned int cycle;       /* SMC Cycle width in MCK ticks */
 	unsigned int setup;       /* SMC Setup width in MCK ticks */
 	unsigned int pulse;       /* CFIOR and CFIOW pulse width in MCK ticks */
 	unsigned int cs_pulse;    /* CS4 or CS5 pulse width in MCK ticks*/
 	unsigned int tdf_cycles;  /* SMC TDF MCK ticks */
 	unsigned long mck_hz;     /* MCK frequency in Hz */

 	t6z = (ata->mode < XFER_PIO_5) ? 30 : 20;
 	mck_hz = clk_get_rate(info->mck);
 	cycle = calc_mck_cycles(ata->cyc8b, mck_hz);
 	setup = calc_mck_cycles(ata->setup, mck_hz);
 	pulse = calc_mck_cycles(ata->act8b, mck_hz);
 	tdf_cycles = calc_mck_cycles(t6z, mck_hz);

 	do {
 		ret = calc_smc_vals(dev, &setup, &pulse, &cycle, &cs_pulse);
 	} while (ret == -ER_SMC_RECALC);

 	if (ret == -ER_SMC_CALC)
 		dev_err(dev, "Interface may not operate correctly\n");

 	dev_dbg(dev, "SMC Setup=%u, Pulse=%u, Cycle=%u, CS Pulse=%u\n",
 		setup, pulse, cycle, cs_pulse);
 	to_smc_format(&setup, &pulse, &cycle, &cs_pulse);
 	/* disable or enable waiting for IORDY signal */
 	use_iordy = ata_pio_need_iordy(adev);
 	if (use_iordy)
 		info->mode |= AT91_SMC_EXNWMODE_READY;

 	if (tdf_cycles > 15) {
 		tdf_cycles = 15;
 		dev_warn(dev, "maximal SMC TDF Cycles value\n");
 	}

 	dev_dbg(dev, "Use IORDY=%u, TDF Cycles=%u\n", use_iordy, tdf_cycles);

 	/* SMC Setup Register */
 	smc.nwe_setup = smc.nrd_setup = setup;
 	smc.ncs_write_setup = smc.ncs_read_setup = 0;
 	/* SMC Pulse Register */
 	smc.nwe_pulse = smc.nrd_pulse = pulse;
 	smc.ncs_write_pulse = smc.ncs_read_pulse = cs_pulse;
 	/* SMC Cycle Register */
 	smc.write_cycle = smc.read_cycle = cycle;
 	/* SMC Mode Register*/
 	smc.tdf_cycles = tdf_cycles;
 	smc.mode = info->mode;

 	sam9_smc_configure(0, info->cs, &smc);
 }

 static void pata_at91_set_piomode(struct ata_port *ap, struct ata_device *adev)
 {
 	struct at91_ide_info *info = ap->host->private_data;
 	struct ata_timing timing;
 	int ret;

 	/* Compute ATA timing and set it to SMC */
 	ret = ata_timing_compute(adev, adev->pio_mode, &timing, 1000, 0);
 	if (ret) {
 		dev_warn(ap->dev, "Failed to compute ATA timing %d, "
 			 "set PIO_0 timing\n", ret);
 		timing = *ata_timing_find_mode(XFER_PIO_0);
 	}
 	set_smc_timing(ap->dev, adev, info, &timing);
 }

 static unsigned int pata_at91_data_xfer_noirq(struct ata_device *dev,
 		unsigned char *buf, unsigned int buflen, int rw)
 {
 	struct at91_ide_info *info = dev->link->ap->host->private_data;
 	unsigned int consumed;
 	unsigned long flags;
 	struct sam9_smc_config smc;

 	local_irq_save(flags);
 	sam9_smc_read_mode(0, info->cs, &smc);

 	/* set 16bit mode before writing data */
 	smc.mode = (smc.mode & ~AT91_SMC_DBW) | AT91_SMC_DBW_16;
 	sam9_smc_write_mode(0, info->cs, &smc);

 	consumed = ata_sff_data_xfer(dev, buf, buflen, rw);

 	/* restore 8bit mode after data is written */
 	smc.mode = (smc.mode & ~AT91_SMC_DBW) | AT91_SMC_DBW_8;
 	sam9_smc_write_mode(0, info->cs, &smc);

 	local_irq_restore(flags);
 	return consumed;
 }

 static struct scsi_host_template pata_at91_sht = {
 	ATA_PIO_SHT(DRV_NAME),
 };

 static struct ata_port_operations pata_at91_port_ops = {
 	.inherits	= &ata_sff_port_ops,

 	.sff_data_xfer	= pata_at91_data_xfer_noirq,
 	.set_piomode	= pata_at91_set_piomode,
 	.cable_detect	= ata_cable_40wire,
 };

 static int pata_at91_probe(struct platform_device *pdev)
 {
 	struct at91_cf_data *board = dev_get_platdata(&pdev->dev);
 	struct device *dev = &pdev->dev;
 	struct at91_ide_info *info;
 	struct resource *mem_res;
 	struct ata_host *host;
 	struct ata_port *ap;

 	int irq_flags = 0;
 	int irq = 0;
 	int ret;

 	/*  get platform resources: IO/CTL memories and irq/rst pins */

 	if (pdev->num_resources != 1) {
 		dev_err(&pdev->dev, "invalid number of resources\n");
 		return -EINVAL;
 	}

 	mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

 	if (!mem_res) {
 		dev_err(dev, "failed to get mem resource\n");
 		return -EINVAL;
 	}

 	irq = board->irq_pin;

 	/* init ata host */

 	host = ata_host_alloc(dev, 1);

 	if (!host)
 		return -ENOMEM;

 	ap = host->ports[0];
 	ap->ops = &pata_at91_port_ops;
 	ap->flags |= ATA_FLAG_SLAVE_POSS;
 	ap->pio_mask = ATA_PIO4;

 	if (!gpio_is_valid(irq)) {
 		ap->flags |= ATA_FLAG_PIO_POLLING;
 		ata_port_desc(ap, "no IRQ, using PIO polling");
 	}

 	info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);

 	if (!info) {
 		dev_err(dev, "failed to allocate memory for private data\n");
 		return -ENOMEM;
 	}

 	info->mck = clk_get(NULL, "mck");

 	if (IS_ERR(info->mck)) {
 		dev_err(dev, "failed to get access to mck clock\n");
 		return -ENODEV;
 	}

 	info->cs    = board->chipselect;
 	info->mode  = AT91_SMC_READMODE | AT91_SMC_WRITEMODE |
 		AT91_SMC_EXNWMODE_READY | AT91_SMC_BAT_SELECT |
 		AT91_SMC_DBW_8 | AT91_SMC_TDF_(0);

 	info->ide_addr = devm_ioremap(dev,
 			mem_res->start + CF_IDE_OFFSET, CF_IDE_RES_SIZE);

 	if (!info->ide_addr) {
 		dev_err(dev, "failed to map IO base\n");
 		ret = -ENOMEM;
 		goto err_put;
 	}

 	info->alt_addr = devm_ioremap(dev,
 			mem_res->start + CF_ALT_IDE_OFFSET, CF_IDE_RES_SIZE);

 	if (!info->alt_addr) {
 		dev_err(dev, "failed to map CTL base\n");
 		ret = -ENOMEM;
 		goto err_put;
 	}

 	ap->ioaddr.cmd_addr = info->ide_addr;
 	ap->ioaddr.ctl_addr = info->alt_addr + 0x06;
 	ap->ioaddr.altstatus_addr = ap->ioaddr.ctl_addr;

 	ata_sff_std_ports(&ap->ioaddr);

 	ata_port_desc(ap, "mmio cmd 0x%llx ctl 0x%llx",
 			(unsigned long long)mem_res->start + CF_IDE_OFFSET,
 			(unsigned long long)mem_res->start + CF_ALT_IDE_OFFSET);

 	host->private_data = info;

 	return ata_host_activate(host, gpio_is_valid(irq) ? gpio_to_irq(irq) : 0,
 			gpio_is_valid(irq) ? ata_sff_interrupt : NULL,
 			irq_flags, &pata_at91_sht);

 	if (!ret)
 		return 0;

 err_put:
 	clk_put(info->mck);
 	return ret;
 }

 static int pata_at91_remove(struct platform_device *pdev)
 {
 	struct ata_host *host = platform_get_drvdata(pdev);
 	struct at91_ide_info *info;

 	if (!host)
 		return 0;
 	info = host->private_data;

 	ata_host_detach(host);

 	if (!info)
 		return 0;

 	clk_put(info->mck);

 	return 0;
 }

 static struct platform_driver pata_at91_driver = {
 	.probe		= pata_at91_probe,
 	.remove		= pata_at91_remove,
 	.driver		= {
 		.name		= DRV_NAME,
 		.owner		= THIS_MODULE,
 	},
 };

 module_platform_driver(pata_at91_driver);

 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("Driver for CF in True IDE mode on AT91SAM9260 SoC");
 MODULE_AUTHOR("Matyukevich Sergey");
 MODULE_VERSION(DRV_VERSION);
	/*
	* PATA driver for AT91SAM9260 Static Memory Controller
	* with CompactFlash interface in True IDE mode
	*
	* Copyright (C) 2009 Matyukevich Sergey
	* 2011 Igor Plyatov
	*
	* Based on:
	* * generic platform driver by Paul Mundt: drivers/ata/pata_platform.c
	* * pata_at32 driver by Kristoffer Nyborg Gregertsen
	* * at91_ide driver by Stanislaw Gruszka
	*
	* 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/kernel.h>
	#include <linux/module.h>
	#include <linux/init.h>
	#include <linux/blkdev.h>
	#include <linux/gfp.h>
	#include <scsi/scsi_host.h>
	#include <linux/ata.h>
	#include <linux/clk.h>
	#include <linux/libata.h>
	#include <linux/platform_device.h>
	#include <linux/ata_platform.h>
	#include <linux/platform_data/atmel.h>

	#include <mach/at91sam9_smc.h>
	#include <asm/gpio.h>

	#define DRV_NAME "pata_at91"
	#define DRV_VERSION "0.3"

	#define CF_IDE_OFFSET 0x00c00000
	#define CF_ALT_IDE_OFFSET 0x00e00000
	#define CF_IDE_RES_SIZE 0x08
	#define CS_PULSE_MAXIMUM 319
	#define ER_SMC_CALC 1
	#define ER_SMC_RECALC 2

	struct at91_ide_info {
	unsigned long mode;
	unsigned int cs;
	struct clk *mck;
	void __iomem *ide_addr;
	void __iomem *alt_addr;
	};

	/**
	* struct smc_range - range of valid values for SMC register.
	*/
	struct smc_range {
	int min;
	int max;
	};

	/**
	* adjust_smc_value - adjust value for one of SMC registers.
	* @value: adjusted value
	* @range: array of SMC ranges with valid values
	* @size: SMC ranges array size
	*
	* This returns the difference between input and output value or negative
	* in case of invalid input value.
	* If negative returned, then output value = maximal possible from ranges.
	*/
	static int adjust_smc_value(int value, struct smc_range range, int size)
	{
	int maximum = (range + size - 1)->max;
	int remainder;

	do {
	if (*value < range->min) {
	remainder = range->min - *value;
	value = range->min; / nearest valid value */
	return remainder;
	} else if ((range->min <= value) && (value <= range->max))
	return 0;

	range++;
	} while (--size);
	*value = maximum;

	return -1; /* invalid value */
	}

	/**
	* calc_smc_vals - calculate SMC register values
	* @dev: ATA device
	* @setup: SMC_SETUP register value
	* @pulse: SMC_PULSE register value
	* @cycle: SMC_CYCLE register value
	*
	* This returns negative in case of invalid values for SMC registers:
	* -ER_SMC_RECALC - recalculation required for SMC values,
	* -ER_SMC_CALC - calculation failed (invalid input values).
	*
	* SMC use special coding scheme, see "Coding and Range of Timing
	* Parameters" table from AT91SAM9 datasheets.
	*
	* SMC_SETUP = 128*setup[5] + setup[4:0]
	* SMC_PULSE = 256*pulse[6] + pulse[5:0]
	* SMC_CYCLE = 256*cycle[8:7] + cycle[6:0]
	*/
	static int calc_smc_vals(struct device *dev,
	int setup, int pulse, int cycle, int cs_pulse)
	{
	int ret_val;
	int err = 0;
	struct smc_range range_setup[] = { /* SMC_SETUP valid values */
	{.min = 0, .max = 31}, /* first range */
	{.min = 128, .max = 159} /* second range */
	};
	struct smc_range range_pulse[] = { /* SMC_PULSE valid values */
	{.min = 0, .max = 63}, /* first range */
	{.min = 256, .max = 319} /* second range */
	};
	struct smc_range range_cycle[] = { /* SMC_CYCLE valid values */
	{.min = 0, .max = 127}, /* first range */
	{.min = 256, .max = 383}, /* second range */
	{.min = 512, .max = 639}, /* third range */
	{.min = 768, .max = 895} /* fourth range */
	};

	ret_val = adjust_smc_value(setup, range_setup, ARRAY_SIZE(range_setup));
	if (ret_val < 0)
	dev_warn(dev, "maximal SMC Setup value\n");
	else
	*cycle += ret_val;

	ret_val = adjust_smc_value(pulse, range_pulse, ARRAY_SIZE(range_pulse));
	if (ret_val < 0)
	dev_warn(dev, "maximal SMC Pulse value\n");
	else
	*cycle += ret_val;

	ret_val = adjust_smc_value(cycle, range_cycle, ARRAY_SIZE(range_cycle));
	if (ret_val < 0)
	dev_warn(dev, "maximal SMC Cycle value\n");

	cs_pulse = cycle;
	if (*cs_pulse > CS_PULSE_MAXIMUM) {
	dev_err(dev, "unable to calculate valid SMC settings\n");
	return -ER_SMC_CALC;
	}

	ret_val = adjust_smc_value(cs_pulse, range_pulse,
	ARRAY_SIZE(range_pulse));
	if (ret_val < 0) {
	dev_warn(dev, "maximal SMC CS Pulse value\n");
	} else if (ret_val != 0) {
	cycle = cs_pulse;
	dev_warn(dev, "SMC Cycle extended\n");
	err = -ER_SMC_RECALC;
	}

	return err;
	}

	/**
	* to_smc_format - convert values into SMC format
	* @setup: SETUP value of SMC Setup Register
	* @pulse: PULSE value of SMC Pulse Register
	* @cycle: CYCLE value of SMC Cycle Register
	* @cs_pulse: NCS_PULSE value of SMC Pulse Register
	*/
	static void to_smc_format(int setup, int pulse, int cycle, int cs_pulse)
	{
	setup = (setup & 0x1f) \| ((*setup & 0x80) >> 2);
	pulse = (pulse & 0x3f) \| ((*pulse & 0x100) >> 2);
	cycle = (cycle & 0x7f) \| ((*cycle & 0x300) >> 1);
	cs_pulse = (cs_pulse & 0x3f) \| ((*cs_pulse & 0x100) >> 2);
	}

	static unsigned long calc_mck_cycles(unsigned long ns, unsigned long mck_hz)
	{
	unsigned long mul;

	/*
	* cycles = x [nsec] * f [Hz] / 10^9 [ns in sec] =
	* x * (f / 1_000_000_000) =
	* x * ((f * 65536) / 1_000_000_000) / 65536 =
	* x * (((f / 10_000) * 65536) / 100_000) / 65536 =
	*/

	mul = (mck_hz / 10000) << 16;
	mul /= 100000;

	return (ns * mul + 65536) >> 16; /* rounding */
	}

	/**
	* set_smc_timing - SMC timings setup.
	* @dev: device
	* @info: AT91 IDE info
	* @ata: ATA timings
	*
	* Its assumed that write timings are same as read timings,
	* cs_setup = 0 and cs_pulse = cycle.
	*/
	static void set_smc_timing(struct device dev, struct ata_device adev,
	struct at91_ide_info info, const struct ata_timing ata)
	{
	int ret = 0;
	int use_iordy;
	struct sam9_smc_config smc;
	unsigned int t6z; /* data tristate time in ns */
	unsigned int cycle; /* SMC Cycle width in MCK ticks */
	unsigned int setup; /* SMC Setup width in MCK ticks */
	unsigned int pulse; /* CFIOR and CFIOW pulse width in MCK ticks */
	unsigned int cs_pulse; /* CS4 or CS5 pulse width in MCK ticks*/
	unsigned int tdf_cycles; /* SMC TDF MCK ticks */
	unsigned long mck_hz; /* MCK frequency in Hz */

	t6z = (ata->mode < XFER_PIO_5) ? 30 : 20;
	mck_hz = clk_get_rate(info->mck);
	cycle = calc_mck_cycles(ata->cyc8b, mck_hz);
	setup = calc_mck_cycles(ata->setup, mck_hz);
	pulse = calc_mck_cycles(ata->act8b, mck_hz);
	tdf_cycles = calc_mck_cycles(t6z, mck_hz);

	do {
	ret = calc_smc_vals(dev, &setup, &pulse, &cycle, &cs_pulse);
	} while (ret == -ER_SMC_RECALC);

	if (ret == -ER_SMC_CALC)
	dev_err(dev, "Interface may not operate correctly\n");

	dev_dbg(dev, "SMC Setup=%u, Pulse=%u, Cycle=%u, CS Pulse=%u\n",
	setup, pulse, cycle, cs_pulse);
	to_smc_format(&setup, &pulse, &cycle, &cs_pulse);
	/* disable or enable waiting for IORDY signal */
	use_iordy = ata_pio_need_iordy(adev);
	if (use_iordy)
	info->mode \|= AT91_SMC_EXNWMODE_READY;

	if (tdf_cycles > 15) {
	tdf_cycles = 15;
	dev_warn(dev, "maximal SMC TDF Cycles value\n");
	}

	dev_dbg(dev, "Use IORDY=%u, TDF Cycles=%u\n", use_iordy, tdf_cycles);

	/* SMC Setup Register */
	smc.nwe_setup = smc.nrd_setup = setup;
	smc.ncs_write_setup = smc.ncs_read_setup = 0;
	/* SMC Pulse Register */
	smc.nwe_pulse = smc.nrd_pulse = pulse;
	smc.ncs_write_pulse = smc.ncs_read_pulse = cs_pulse;
	/* SMC Cycle Register */
	smc.write_cycle = smc.read_cycle = cycle;
	/* SMC Mode Register*/
	smc.tdf_cycles = tdf_cycles;
	smc.mode = info->mode;

	sam9_smc_configure(0, info->cs, &smc);
	}

	static void pata_at91_set_piomode(struct ata_port ap, struct ata_device adev)
	{
	struct at91_ide_info *info = ap->host->private_data;
	struct ata_timing timing;
	int ret;

	/* Compute ATA timing and set it to SMC */
	ret = ata_timing_compute(adev, adev->pio_mode, &timing, 1000, 0);
	if (ret) {
	dev_warn(ap->dev, "Failed to compute ATA timing %d, "
	"set PIO_0 timing\n", ret);
	timing = *ata_timing_find_mode(XFER_PIO_0);
	}
	set_smc_timing(ap->dev, adev, info, &timing);
	}

	static unsigned int pata_at91_data_xfer_noirq(struct ata_device *dev,
	unsigned char *buf, unsigned int buflen, int rw)
	{
	struct at91_ide_info *info = dev->link->ap->host->private_data;
	unsigned int consumed;
	unsigned long flags;
	struct sam9_smc_config smc;

	local_irq_save(flags);
	sam9_smc_read_mode(0, info->cs, &smc);

	/* set 16bit mode before writing data */
	smc.mode = (smc.mode & ~AT91_SMC_DBW) \| AT91_SMC_DBW_16;
	sam9_smc_write_mode(0, info->cs, &smc);

	consumed = ata_sff_data_xfer(dev, buf, buflen, rw);

	/* restore 8bit mode after data is written */
	smc.mode = (smc.mode & ~AT91_SMC_DBW) \| AT91_SMC_DBW_8;
	sam9_smc_write_mode(0, info->cs, &smc);

	local_irq_restore(flags);
	return consumed;
	}

	static struct scsi_host_template pata_at91_sht = {
	ATA_PIO_SHT(DRV_NAME),
	};

	static struct ata_port_operations pata_at91_port_ops = {
	.inherits = &ata_sff_port_ops,

	.sff_data_xfer = pata_at91_data_xfer_noirq,
	.set_piomode = pata_at91_set_piomode,
	.cable_detect = ata_cable_40wire,
	};

	static int pata_at91_probe(struct platform_device *pdev)
	{
	struct at91_cf_data *board = dev_get_platdata(&pdev->dev);
	struct device *dev = &pdev->dev;
	struct at91_ide_info *info;
	struct resource *mem_res;
	struct ata_host *host;
	struct ata_port *ap;

	int irq_flags = 0;
	int irq = 0;
	int ret;

	/* get platform resources: IO/CTL memories and irq/rst pins */

	if (pdev->num_resources != 1) {
	dev_err(&pdev->dev, "invalid number of resources\n");
	return -EINVAL;
	}

	mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

	if (!mem_res) {
	dev_err(dev, "failed to get mem resource\n");
	return -EINVAL;
	}

	irq = board->irq_pin;

	/* init ata host */

	host = ata_host_alloc(dev, 1);

	if (!host)
	return -ENOMEM;

	ap = host->ports[0];
	ap->ops = &pata_at91_port_ops;
	ap->flags \|= ATA_FLAG_SLAVE_POSS;
	ap->pio_mask = ATA_PIO4;

	if (!gpio_is_valid(irq)) {
	ap->flags \|= ATA_FLAG_PIO_POLLING;
	ata_port_desc(ap, "no IRQ, using PIO polling");
	}

	info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);

	if (!info) {
	dev_err(dev, "failed to allocate memory for private data\n");
	return -ENOMEM;
	}

	info->mck = clk_get(NULL, "mck");

	if (IS_ERR(info->mck)) {
	dev_err(dev, "failed to get access to mck clock\n");
	return -ENODEV;
	}

	info->cs = board->chipselect;
	info->mode = AT91_SMC_READMODE \| AT91_SMC_WRITEMODE \|
	AT91_SMC_EXNWMODE_READY \| AT91_SMC_BAT_SELECT \|
	AT91_SMC_DBW_8 \| AT91_SMC_TDF_(0);

	info->ide_addr = devm_ioremap(dev,
	mem_res->start + CF_IDE_OFFSET, CF_IDE_RES_SIZE);

	if (!info->ide_addr) {
	dev_err(dev, "failed to map IO base\n");
	ret = -ENOMEM;
	goto err_put;
	}

	info->alt_addr = devm_ioremap(dev,
	mem_res->start + CF_ALT_IDE_OFFSET, CF_IDE_RES_SIZE);

	if (!info->alt_addr) {
	dev_err(dev, "failed to map CTL base\n");
	ret = -ENOMEM;
	goto err_put;
	}

	ap->ioaddr.cmd_addr = info->ide_addr;
	ap->ioaddr.ctl_addr = info->alt_addr + 0x06;
	ap->ioaddr.altstatus_addr = ap->ioaddr.ctl_addr;

	ata_sff_std_ports(&ap->ioaddr);

	ata_port_desc(ap, "mmio cmd 0x%llx ctl 0x%llx",
	(unsigned long long)mem_res->start + CF_IDE_OFFSET,
	(unsigned long long)mem_res->start + CF_ALT_IDE_OFFSET);

	host->private_data = info;

	return ata_host_activate(host, gpio_is_valid(irq) ? gpio_to_irq(irq) : 0,
	gpio_is_valid(irq) ? ata_sff_interrupt : NULL,
	irq_flags, &pata_at91_sht);

	if (!ret)
	return 0;

	err_put:
	clk_put(info->mck);
	return ret;
	}

	static int pata_at91_remove(struct platform_device *pdev)
	{
	struct ata_host *host = platform_get_drvdata(pdev);
	struct at91_ide_info *info;

	if (!host)
	return 0;
	info = host->private_data;

	ata_host_detach(host);

	if (!info)
	return 0;

	clk_put(info->mck);

	return 0;
	}

	static struct platform_driver pata_at91_driver = {
	.probe = pata_at91_probe,
	.remove = pata_at91_remove,
	.driver = {
	.name = DRV_NAME,
	.owner = THIS_MODULE,
	},
	};

	module_platform_driver(pata_at91_driver);

	MODULE_LICENSE("GPL");
	MODULE_DESCRIPTION("Driver for CF in True IDE mode on AT91SAM9260 SoC");
	MODULE_AUTHOR("Matyukevich Sergey");
	MODULE_VERSION(DRV_VERSION);