drivers/mfd/atmel-smc.c - linux - Git at Google

 /*
  * Atmel SMC (Static Memory Controller) helper functions.
  *
  * Copyright (C) 2017 Atmel
  * Copyright (C) 2017 Free Electrons
  *
  * Author: Boris Brezillon <boris.brezillon@free-electrons.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.
  */

 #include <linux/mfd/syscon/atmel-smc.h>
 #include <linux/string.h>

 /**
  * atmel_smc_cs_conf_init - initialize a SMC CS conf
  * @conf: the SMC CS conf to initialize
  *
  * Set all fields to 0 so that one can start defining a new config.
  */
 void atmel_smc_cs_conf_init(struct atmel_smc_cs_conf *conf)
 {
 	memset(conf, 0, sizeof(*conf));
 }
 EXPORT_SYMBOL_GPL(atmel_smc_cs_conf_init);

 /**
  * atmel_smc_cs_encode_ncycles - encode a number of MCK clk cycles in the
  *				 format expected by the SMC engine
  * @ncycles: number of MCK clk cycles
  * @msbpos: position of the MSB part of the timing field
  * @msbwidth: width of the MSB part of the timing field
  * @msbfactor: factor applied to the MSB
  * @encodedval: param used to store the encoding result
  *
  * This function encodes the @ncycles value as described in the datasheet
  * (section "SMC Setup/Pulse/Cycle/Timings Register"). This is a generic
  * helper which called with different parameter depending on the encoding
  * scheme.
  *
  * If the @ncycles value is too big to be encoded, -ERANGE is returned and
  * the encodedval is contains the maximum val. Otherwise, 0 is returned.
  */
 static int atmel_smc_cs_encode_ncycles(unsigned int ncycles,
 				       unsigned int msbpos,
 				       unsigned int msbwidth,
 				       unsigned int msbfactor,
 				       unsigned int *encodedval)
 {
 	unsigned int lsbmask = GENMASK(msbpos - 1, 0);
 	unsigned int msbmask = GENMASK(msbwidth - 1, 0);
 	unsigned int msb, lsb;
 	int ret = 0;

 	msb = ncycles / msbfactor;
 	lsb = ncycles % msbfactor;

 	if (lsb > lsbmask) {
 		lsb = 0;
 		msb++;
 	}

 	/*
 	 * Let's just put the maximum we can if the requested setting does
 	 * not fit in the register field.
 	 * We still return -ERANGE in case the caller cares.
 	 */
 	if (msb > msbmask) {
 		msb = msbmask;
 		lsb = lsbmask;
 		ret = -ERANGE;
 	}

 	*encodedval = (msb << msbpos) | lsb;

 	return ret;
 }

 /**
  * atmel_smc_cs_conf_set_timing - set the SMC CS conf Txx parameter to a
  *				  specific value
  * @conf: SMC CS conf descriptor
  * @shift: the position of the Txx field in the TIMINGS register
  * @ncycles: value (expressed in MCK clk cycles) to assign to this Txx
  *	     parameter
  *
  * This function encodes the @ncycles value as described in the datasheet
  * (section "SMC Timings Register"), and then stores the result in the
  * @conf->timings field at @shift position.
  *
  * Returns -EINVAL if shift is invalid, -ERANGE if ncycles does not fit in
  * the field, and 0 otherwise.
  */
 int atmel_smc_cs_conf_set_timing(struct atmel_smc_cs_conf *conf,
 				 unsigned int shift, unsigned int ncycles)
 {
 	unsigned int val;
 	int ret;

 	if (shift != ATMEL_HSMC_TIMINGS_TCLR_SHIFT &&
 	    shift != ATMEL_HSMC_TIMINGS_TADL_SHIFT &&
 	    shift != ATMEL_HSMC_TIMINGS_TAR_SHIFT &&
 	    shift != ATMEL_HSMC_TIMINGS_TRR_SHIFT &&
 	    shift != ATMEL_HSMC_TIMINGS_TWB_SHIFT)
 		return -EINVAL;

 	/*
 	 * The formula described in atmel datasheets (section "HSMC Timings
 	 * Register"):
 	 *
 	 * ncycles = (Txx[3] * 64) + Txx[2:0]
 	 */
 	ret = atmel_smc_cs_encode_ncycles(ncycles, 3, 1, 64, &val);
 	conf->timings &= ~GENMASK(shift + 3, shift);
 	conf->timings |= val << shift;

 	return ret;
 }
 EXPORT_SYMBOL_GPL(atmel_smc_cs_conf_set_timing);

 /**
  * atmel_smc_cs_conf_set_setup - set the SMC CS conf xx_SETUP parameter to a
  *				 specific value
  * @conf: SMC CS conf descriptor
  * @shift: the position of the xx_SETUP field in the SETUP register
  * @ncycles: value (expressed in MCK clk cycles) to assign to this xx_SETUP
  *	     parameter
  *
  * This function encodes the @ncycles value as described in the datasheet
  * (section "SMC Setup Register"), and then stores the result in the
  * @conf->setup field at @shift position.
  *
  * Returns -EINVAL if @shift is invalid, -ERANGE if @ncycles does not fit in
  * the field, and 0 otherwise.
  */
 int atmel_smc_cs_conf_set_setup(struct atmel_smc_cs_conf *conf,
 				unsigned int shift, unsigned int ncycles)
 {
 	unsigned int val;
 	int ret;

 	if (shift != ATMEL_SMC_NWE_SHIFT && shift != ATMEL_SMC_NCS_WR_SHIFT &&
 	    shift != ATMEL_SMC_NRD_SHIFT && shift != ATMEL_SMC_NCS_RD_SHIFT)
 		return -EINVAL;

 	/*
 	 * The formula described in atmel datasheets (section "SMC Setup
 	 * Register"):
 	 *
 	 * ncycles = (128 * xx_SETUP[5]) + xx_SETUP[4:0]
 	 */
 	ret = atmel_smc_cs_encode_ncycles(ncycles, 5, 1, 128, &val);
 	conf->setup &= ~GENMASK(shift + 7, shift);
 	conf->setup |= val << shift;

 	return ret;
 }
 EXPORT_SYMBOL_GPL(atmel_smc_cs_conf_set_setup);

 /**
  * atmel_smc_cs_conf_set_pulse - set the SMC CS conf xx_PULSE parameter to a
  *				 specific value
  * @conf: SMC CS conf descriptor
  * @shift: the position of the xx_PULSE field in the PULSE register
  * @ncycles: value (expressed in MCK clk cycles) to assign to this xx_PULSE
  *	     parameter
  *
  * This function encodes the @ncycles value as described in the datasheet
  * (section "SMC Pulse Register"), and then stores the result in the
  * @conf->setup field at @shift position.
  *
  * Returns -EINVAL if @shift is invalid, -ERANGE if @ncycles does not fit in
  * the field, and 0 otherwise.
  */
 int atmel_smc_cs_conf_set_pulse(struct atmel_smc_cs_conf *conf,
 				unsigned int shift, unsigned int ncycles)
 {
 	unsigned int val;
 	int ret;

 	if (shift != ATMEL_SMC_NWE_SHIFT && shift != ATMEL_SMC_NCS_WR_SHIFT &&
 	    shift != ATMEL_SMC_NRD_SHIFT && shift != ATMEL_SMC_NCS_RD_SHIFT)
 		return -EINVAL;

 	/*
 	 * The formula described in atmel datasheets (section "SMC Pulse
 	 * Register"):
 	 *
 	 * ncycles = (256 * xx_PULSE[6]) + xx_PULSE[5:0]
 	 */
 	ret = atmel_smc_cs_encode_ncycles(ncycles, 6, 1, 256, &val);
 	conf->pulse &= ~GENMASK(shift + 7, shift);
 	conf->pulse |= val << shift;

 	return ret;
 }
 EXPORT_SYMBOL_GPL(atmel_smc_cs_conf_set_pulse);

 /**
  * atmel_smc_cs_conf_set_cycle - set the SMC CS conf xx_CYCLE parameter to a
  *				 specific value
  * @conf: SMC CS conf descriptor
  * @shift: the position of the xx_CYCLE field in the CYCLE register
  * @ncycles: value (expressed in MCK clk cycles) to assign to this xx_CYCLE
  *	     parameter
  *
  * This function encodes the @ncycles value as described in the datasheet
  * (section "SMC Cycle Register"), and then stores the result in the
  * @conf->setup field at @shift position.
  *
  * Returns -EINVAL if @shift is invalid, -ERANGE if @ncycles does not fit in
  * the field, and 0 otherwise.
  */
 int atmel_smc_cs_conf_set_cycle(struct atmel_smc_cs_conf *conf,
 				unsigned int shift, unsigned int ncycles)
 {
 	unsigned int val;
 	int ret;

 	if (shift != ATMEL_SMC_NWE_SHIFT && shift != ATMEL_SMC_NRD_SHIFT)
 		return -EINVAL;

 	/*
 	 * The formula described in atmel datasheets (section "SMC Cycle
 	 * Register"):
 	 *
 	 * ncycles = (xx_CYCLE[8:7] * 256) + xx_CYCLE[6:0]
 	 */
 	ret = atmel_smc_cs_encode_ncycles(ncycles, 7, 2, 256, &val);
 	conf->cycle &= ~GENMASK(shift + 15, shift);
 	conf->cycle |= val << shift;

 	return ret;
 }
 EXPORT_SYMBOL_GPL(atmel_smc_cs_conf_set_cycle);

 /**
  * atmel_smc_cs_conf_apply - apply an SMC CS conf
  * @regmap: the SMC regmap
  * @cs: the CS id
  * @conf the SMC CS conf to apply
  *
  * Applies an SMC CS configuration.
  * Only valid on at91sam9/avr32 SoCs.
  */
 void atmel_smc_cs_conf_apply(struct regmap *regmap, int cs,
 			     const struct atmel_smc_cs_conf *conf)
 {
 	regmap_write(regmap, ATMEL_SMC_SETUP(cs), conf->setup);
 	regmap_write(regmap, ATMEL_SMC_PULSE(cs), conf->pulse);
 	regmap_write(regmap, ATMEL_SMC_CYCLE(cs), conf->cycle);
 	regmap_write(regmap, ATMEL_SMC_MODE(cs), conf->mode);
 }
 EXPORT_SYMBOL_GPL(atmel_smc_cs_conf_apply);

 /**
  * atmel_hsmc_cs_conf_apply - apply an SMC CS conf
  * @regmap: the HSMC regmap
  * @cs: the CS id
  * @layout: the layout of registers
  * @conf the SMC CS conf to apply
  *
  * Applies an SMC CS configuration.
  * Only valid on post-sama5 SoCs.
  */
 void atmel_hsmc_cs_conf_apply(struct regmap *regmap,
 			      const struct atmel_hsmc_reg_layout *layout,
 			      int cs, const struct atmel_smc_cs_conf *conf)
 {
 	regmap_write(regmap, ATMEL_HSMC_SETUP(layout, cs), conf->setup);
 	regmap_write(regmap, ATMEL_HSMC_PULSE(layout, cs), conf->pulse);
 	regmap_write(regmap, ATMEL_HSMC_CYCLE(layout, cs), conf->cycle);
 	regmap_write(regmap, ATMEL_HSMC_TIMINGS(layout, cs), conf->timings);
 	regmap_write(regmap, ATMEL_HSMC_MODE(layout, cs), conf->mode);
 }
 EXPORT_SYMBOL_GPL(atmel_hsmc_cs_conf_apply);

 /**
  * atmel_smc_cs_conf_get - retrieve the current SMC CS conf
  * @regmap: the SMC regmap
  * @cs: the CS id
  * @conf: the SMC CS conf object to store the current conf
  *
  * Retrieve the SMC CS configuration.
  * Only valid on at91sam9/avr32 SoCs.
  */
 void atmel_smc_cs_conf_get(struct regmap *regmap, int cs,
 			   struct atmel_smc_cs_conf *conf)
 {
 	regmap_read(regmap, ATMEL_SMC_SETUP(cs), &conf->setup);
 	regmap_read(regmap, ATMEL_SMC_PULSE(cs), &conf->pulse);
 	regmap_read(regmap, ATMEL_SMC_CYCLE(cs), &conf->cycle);
 	regmap_read(regmap, ATMEL_SMC_MODE(cs), &conf->mode);
 }
 EXPORT_SYMBOL_GPL(atmel_smc_cs_conf_get);

 /**
  * atmel_hsmc_cs_conf_get - retrieve the current SMC CS conf
  * @regmap: the HSMC regmap
  * @cs: the CS id
  * @layout: the layout of registers
  * @conf: the SMC CS conf object to store the current conf
  *
  * Retrieve the SMC CS configuration.
  * Only valid on post-sama5 SoCs.
  */
 void atmel_hsmc_cs_conf_get(struct regmap *regmap,
 			    const struct atmel_hsmc_reg_layout *layout,
 			    int cs, struct atmel_smc_cs_conf *conf)
 {
 	regmap_read(regmap, ATMEL_HSMC_SETUP(layout, cs), &conf->setup);
 	regmap_read(regmap, ATMEL_HSMC_PULSE(layout, cs), &conf->pulse);
 	regmap_read(regmap, ATMEL_HSMC_CYCLE(layout, cs), &conf->cycle);
 	regmap_read(regmap, ATMEL_HSMC_TIMINGS(layout, cs), &conf->timings);
 	regmap_read(regmap, ATMEL_HSMC_MODE(layout, cs), &conf->mode);
 }
 EXPORT_SYMBOL_GPL(atmel_hsmc_cs_conf_get);

 static const struct atmel_hsmc_reg_layout sama5d3_reg_layout = {
 	.timing_regs_offset = 0x600,
 };

 static const struct atmel_hsmc_reg_layout sama5d2_reg_layout = {
 	.timing_regs_offset = 0x700,
 };

 static const struct of_device_id atmel_smc_ids[] = {
 	{ .compatible = "atmel,at91sam9260-smc", .data = NULL },
 	{ .compatible = "atmel,sama5d3-smc", .data = &sama5d3_reg_layout },
 	{ .compatible = "atmel,sama5d2-smc", .data = &sama5d2_reg_layout },
 	{ /* sentinel */ },
 };

 /**
  * atmel_hsmc_get_reg_layout - retrieve the layout of HSMC registers
  * @np: the HSMC regmap
  *
  * Retrieve the layout of HSMC registers.
  *
  * Returns NULL in case of SMC, a struct atmel_hsmc_reg_layout pointer
  * in HSMC case, otherwise ERR_PTR(-EINVAL).
  */
 const struct atmel_hsmc_reg_layout *
 atmel_hsmc_get_reg_layout(struct device_node *np)
 {
 	const struct of_device_id *match;

 	match = of_match_node(atmel_smc_ids, np);

 	return match ? match->data : ERR_PTR(-EINVAL);
 }
 EXPORT_SYMBOL_GPL(atmel_hsmc_get_reg_layout);
	/*
	* Atmel SMC (Static Memory Controller) helper functions.
	*
	* Copyright (C) 2017 Atmel
	* Copyright (C) 2017 Free Electrons
	*
	* Author: Boris Brezillon <boris.brezillon@free-electrons.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.
	*/

	#include <linux/mfd/syscon/atmel-smc.h>
	#include <linux/string.h>

	/**
	* atmel_smc_cs_conf_init - initialize a SMC CS conf
	* @conf: the SMC CS conf to initialize
	*
	* Set all fields to 0 so that one can start defining a new config.
	*/
	void atmel_smc_cs_conf_init(struct atmel_smc_cs_conf *conf)
	{
	memset(conf, 0, sizeof(*conf));
	}
	EXPORT_SYMBOL_GPL(atmel_smc_cs_conf_init);

	/**
	* atmel_smc_cs_encode_ncycles - encode a number of MCK clk cycles in the
	* format expected by the SMC engine
	* @ncycles: number of MCK clk cycles
	* @msbpos: position of the MSB part of the timing field
	* @msbwidth: width of the MSB part of the timing field
	* @msbfactor: factor applied to the MSB
	* @encodedval: param used to store the encoding result
	*
	* This function encodes the @ncycles value as described in the datasheet
	* (section "SMC Setup/Pulse/Cycle/Timings Register"). This is a generic
	* helper which called with different parameter depending on the encoding
	* scheme.
	*
	* If the @ncycles value is too big to be encoded, -ERANGE is returned and
	* the encodedval is contains the maximum val. Otherwise, 0 is returned.
	*/
	static int atmel_smc_cs_encode_ncycles(unsigned int ncycles,
	unsigned int msbpos,
	unsigned int msbwidth,
	unsigned int msbfactor,
	unsigned int *encodedval)
	{
	unsigned int lsbmask = GENMASK(msbpos - 1, 0);
	unsigned int msbmask = GENMASK(msbwidth - 1, 0);
	unsigned int msb, lsb;
	int ret = 0;

	msb = ncycles / msbfactor;
	lsb = ncycles % msbfactor;

	if (lsb > lsbmask) {
	lsb = 0;
	msb++;
	}

	/*
	* Let's just put the maximum we can if the requested setting does
	* not fit in the register field.
	* We still return -ERANGE in case the caller cares.
	*/
	if (msb > msbmask) {
	msb = msbmask;
	lsb = lsbmask;
	ret = -ERANGE;
	}

	*encodedval = (msb << msbpos) \| lsb;

	return ret;
	}

	/**
	* atmel_smc_cs_conf_set_timing - set the SMC CS conf Txx parameter to a
	* specific value
	* @conf: SMC CS conf descriptor
	* @shift: the position of the Txx field in the TIMINGS register
	* @ncycles: value (expressed in MCK clk cycles) to assign to this Txx
	* parameter
	*
	* This function encodes the @ncycles value as described in the datasheet
	* (section "SMC Timings Register"), and then stores the result in the
	* @conf->timings field at @shift position.
	*
	* Returns -EINVAL if shift is invalid, -ERANGE if ncycles does not fit in
	* the field, and 0 otherwise.
	*/
	int atmel_smc_cs_conf_set_timing(struct atmel_smc_cs_conf *conf,
	unsigned int shift, unsigned int ncycles)
	{
	unsigned int val;
	int ret;

	if (shift != ATMEL_HSMC_TIMINGS_TCLR_SHIFT &&
	shift != ATMEL_HSMC_TIMINGS_TADL_SHIFT &&
	shift != ATMEL_HSMC_TIMINGS_TAR_SHIFT &&
	shift != ATMEL_HSMC_TIMINGS_TRR_SHIFT &&
	shift != ATMEL_HSMC_TIMINGS_TWB_SHIFT)
	return -EINVAL;

	/*
	* The formula described in atmel datasheets (section "HSMC Timings
	* Register"):
	*
	* ncycles = (Txx[3] * 64) + Txx[2:0]
	*/
	ret = atmel_smc_cs_encode_ncycles(ncycles, 3, 1, 64, &val);
	conf->timings &= ~GENMASK(shift + 3, shift);
	conf->timings \|= val << shift;

	return ret;
	}
	EXPORT_SYMBOL_GPL(atmel_smc_cs_conf_set_timing);

	/**
	* atmel_smc_cs_conf_set_setup - set the SMC CS conf xx_SETUP parameter to a
	* specific value
	* @conf: SMC CS conf descriptor
	* @shift: the position of the xx_SETUP field in the SETUP register
	* @ncycles: value (expressed in MCK clk cycles) to assign to this xx_SETUP
	* parameter
	*
	* This function encodes the @ncycles value as described in the datasheet
	* (section "SMC Setup Register"), and then stores the result in the
	* @conf->setup field at @shift position.
	*
	* Returns -EINVAL if @shift is invalid, -ERANGE if @ncycles does not fit in
	* the field, and 0 otherwise.
	*/
	int atmel_smc_cs_conf_set_setup(struct atmel_smc_cs_conf *conf,
	unsigned int shift, unsigned int ncycles)
	{
	unsigned int val;
	int ret;

	if (shift != ATMEL_SMC_NWE_SHIFT && shift != ATMEL_SMC_NCS_WR_SHIFT &&
	shift != ATMEL_SMC_NRD_SHIFT && shift != ATMEL_SMC_NCS_RD_SHIFT)
	return -EINVAL;

	/*
	* The formula described in atmel datasheets (section "SMC Setup
	* Register"):
	*
	* ncycles = (128 * xx_SETUP[5]) + xx_SETUP[4:0]
	*/
	ret = atmel_smc_cs_encode_ncycles(ncycles, 5, 1, 128, &val);
	conf->setup &= ~GENMASK(shift + 7, shift);
	conf->setup \|= val << shift;

	return ret;
	}
	EXPORT_SYMBOL_GPL(atmel_smc_cs_conf_set_setup);

	/**
	* atmel_smc_cs_conf_set_pulse - set the SMC CS conf xx_PULSE parameter to a
	* specific value
	* @conf: SMC CS conf descriptor
	* @shift: the position of the xx_PULSE field in the PULSE register
	* @ncycles: value (expressed in MCK clk cycles) to assign to this xx_PULSE
	* parameter
	*
	* This function encodes the @ncycles value as described in the datasheet
	* (section "SMC Pulse Register"), and then stores the result in the
	* @conf->setup field at @shift position.
	*
	* Returns -EINVAL if @shift is invalid, -ERANGE if @ncycles does not fit in
	* the field, and 0 otherwise.
	*/
	int atmel_smc_cs_conf_set_pulse(struct atmel_smc_cs_conf *conf,
	unsigned int shift, unsigned int ncycles)
	{
	unsigned int val;
	int ret;

	if (shift != ATMEL_SMC_NWE_SHIFT && shift != ATMEL_SMC_NCS_WR_SHIFT &&
	shift != ATMEL_SMC_NRD_SHIFT && shift != ATMEL_SMC_NCS_RD_SHIFT)
	return -EINVAL;

	/*
	* The formula described in atmel datasheets (section "SMC Pulse
	* Register"):
	*
	* ncycles = (256 * xx_PULSE[6]) + xx_PULSE[5:0]
	*/
	ret = atmel_smc_cs_encode_ncycles(ncycles, 6, 1, 256, &val);
	conf->pulse &= ~GENMASK(shift + 7, shift);
	conf->pulse \|= val << shift;

	return ret;
	}
	EXPORT_SYMBOL_GPL(atmel_smc_cs_conf_set_pulse);

	/**
	* atmel_smc_cs_conf_set_cycle - set the SMC CS conf xx_CYCLE parameter to a
	* specific value
	* @conf: SMC CS conf descriptor
	* @shift: the position of the xx_CYCLE field in the CYCLE register
	* @ncycles: value (expressed in MCK clk cycles) to assign to this xx_CYCLE
	* parameter
	*
	* This function encodes the @ncycles value as described in the datasheet
	* (section "SMC Cycle Register"), and then stores the result in the
	* @conf->setup field at @shift position.
	*
	* Returns -EINVAL if @shift is invalid, -ERANGE if @ncycles does not fit in
	* the field, and 0 otherwise.
	*/
	int atmel_smc_cs_conf_set_cycle(struct atmel_smc_cs_conf *conf,
	unsigned int shift, unsigned int ncycles)
	{
	unsigned int val;
	int ret;

	if (shift != ATMEL_SMC_NWE_SHIFT && shift != ATMEL_SMC_NRD_SHIFT)
	return -EINVAL;

	/*
	* The formula described in atmel datasheets (section "SMC Cycle
	* Register"):
	*
	* ncycles = (xx_CYCLE[8:7] * 256) + xx_CYCLE[6:0]
	*/
	ret = atmel_smc_cs_encode_ncycles(ncycles, 7, 2, 256, &val);
	conf->cycle &= ~GENMASK(shift + 15, shift);
	conf->cycle \|= val << shift;

	return ret;
	}
	EXPORT_SYMBOL_GPL(atmel_smc_cs_conf_set_cycle);

	/**
	* atmel_smc_cs_conf_apply - apply an SMC CS conf
	* @regmap: the SMC regmap
	* @cs: the CS id
	* @conf the SMC CS conf to apply
	*
	* Applies an SMC CS configuration.
	* Only valid on at91sam9/avr32 SoCs.
	*/
	void atmel_smc_cs_conf_apply(struct regmap *regmap, int cs,
	const struct atmel_smc_cs_conf *conf)
	{
	regmap_write(regmap, ATMEL_SMC_SETUP(cs), conf->setup);
	regmap_write(regmap, ATMEL_SMC_PULSE(cs), conf->pulse);
	regmap_write(regmap, ATMEL_SMC_CYCLE(cs), conf->cycle);
	regmap_write(regmap, ATMEL_SMC_MODE(cs), conf->mode);
	}
	EXPORT_SYMBOL_GPL(atmel_smc_cs_conf_apply);

	/**
	* atmel_hsmc_cs_conf_apply - apply an SMC CS conf
	* @regmap: the HSMC regmap
	* @cs: the CS id
	* @layout: the layout of registers
	* @conf the SMC CS conf to apply
	*
	* Applies an SMC CS configuration.
	* Only valid on post-sama5 SoCs.
	*/
	void atmel_hsmc_cs_conf_apply(struct regmap *regmap,
	const struct atmel_hsmc_reg_layout *layout,
	int cs, const struct atmel_smc_cs_conf *conf)
	{
	regmap_write(regmap, ATMEL_HSMC_SETUP(layout, cs), conf->setup);
	regmap_write(regmap, ATMEL_HSMC_PULSE(layout, cs), conf->pulse);
	regmap_write(regmap, ATMEL_HSMC_CYCLE(layout, cs), conf->cycle);
	regmap_write(regmap, ATMEL_HSMC_TIMINGS(layout, cs), conf->timings);
	regmap_write(regmap, ATMEL_HSMC_MODE(layout, cs), conf->mode);
	}
	EXPORT_SYMBOL_GPL(atmel_hsmc_cs_conf_apply);

	/**
	* atmel_smc_cs_conf_get - retrieve the current SMC CS conf
	* @regmap: the SMC regmap
	* @cs: the CS id
	* @conf: the SMC CS conf object to store the current conf
	*
	* Retrieve the SMC CS configuration.
	* Only valid on at91sam9/avr32 SoCs.
	*/
	void atmel_smc_cs_conf_get(struct regmap *regmap, int cs,
	struct atmel_smc_cs_conf *conf)
	{
	regmap_read(regmap, ATMEL_SMC_SETUP(cs), &conf->setup);
	regmap_read(regmap, ATMEL_SMC_PULSE(cs), &conf->pulse);
	regmap_read(regmap, ATMEL_SMC_CYCLE(cs), &conf->cycle);
	regmap_read(regmap, ATMEL_SMC_MODE(cs), &conf->mode);
	}
	EXPORT_SYMBOL_GPL(atmel_smc_cs_conf_get);

	/**
	* atmel_hsmc_cs_conf_get - retrieve the current SMC CS conf
	* @regmap: the HSMC regmap
	* @cs: the CS id
	* @layout: the layout of registers
	* @conf: the SMC CS conf object to store the current conf
	*
	* Retrieve the SMC CS configuration.
	* Only valid on post-sama5 SoCs.
	*/
	void atmel_hsmc_cs_conf_get(struct regmap *regmap,
	const struct atmel_hsmc_reg_layout *layout,
	int cs, struct atmel_smc_cs_conf *conf)
	{
	regmap_read(regmap, ATMEL_HSMC_SETUP(layout, cs), &conf->setup);
	regmap_read(regmap, ATMEL_HSMC_PULSE(layout, cs), &conf->pulse);
	regmap_read(regmap, ATMEL_HSMC_CYCLE(layout, cs), &conf->cycle);
	regmap_read(regmap, ATMEL_HSMC_TIMINGS(layout, cs), &conf->timings);
	regmap_read(regmap, ATMEL_HSMC_MODE(layout, cs), &conf->mode);
	}
	EXPORT_SYMBOL_GPL(atmel_hsmc_cs_conf_get);

	static const struct atmel_hsmc_reg_layout sama5d3_reg_layout = {
	.timing_regs_offset = 0x600,
	};

	static const struct atmel_hsmc_reg_layout sama5d2_reg_layout = {
	.timing_regs_offset = 0x700,
	};

	static const struct of_device_id atmel_smc_ids[] = {
	{ .compatible = "atmel,at91sam9260-smc", .data = NULL },
	{ .compatible = "atmel,sama5d3-smc", .data = &sama5d3_reg_layout },
	{ .compatible = "atmel,sama5d2-smc", .data = &sama5d2_reg_layout },
	{ /* sentinel */ },
	};

	/**
	* atmel_hsmc_get_reg_layout - retrieve the layout of HSMC registers
	* @np: the HSMC regmap
	*
	* Retrieve the layout of HSMC registers.
	*
	* Returns NULL in case of SMC, a struct atmel_hsmc_reg_layout pointer
	* in HSMC case, otherwise ERR_PTR(-EINVAL).
	*/
	const struct atmel_hsmc_reg_layout *
	atmel_hsmc_get_reg_layout(struct device_node *np)
	{
	const struct of_device_id *match;

	match = of_match_node(atmel_smc_ids, np);

	return match ? match->data : ERR_PTR(-EINVAL);
	}
	EXPORT_SYMBOL_GPL(atmel_hsmc_get_reg_layout);