| // SPDX-License-Identifier: GPL-2.0-only | 
 | /* | 
 |  * Atmel SMC (Static Memory Controller) helper functions. | 
 |  * | 
 |  * Copyright (C) 2017 Atmel | 
 |  * Copyright (C) 2017 Free Electrons | 
 |  * | 
 |  * Author: Boris Brezillon <[email protected]> | 
 |  */ | 
 |  | 
 | #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); |