|  | /* | 
|  | * Atmel SMC (Static Memory Controller) helper functions. | 
|  | * | 
|  | * Copyright (C) 2017 Atmel | 
|  | * Copyright (C) 2017 Free Electrons | 
|  | * | 
|  | * Author: Boris Brezillon <[email protected]> | 
|  | * | 
|  | * 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> | 
|  |  | 
|  | /** | 
|  | * 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 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_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 | 
|  | * @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, int cs, | 
|  | const struct atmel_smc_cs_conf *conf) | 
|  | { | 
|  | regmap_write(regmap, ATMEL_HSMC_SETUP(cs), conf->setup); | 
|  | regmap_write(regmap, ATMEL_HSMC_PULSE(cs), conf->pulse); | 
|  | regmap_write(regmap, ATMEL_HSMC_CYCLE(cs), conf->cycle); | 
|  | regmap_write(regmap, ATMEL_HSMC_TIMINGS(cs), conf->timings); | 
|  | regmap_write(regmap, ATMEL_HSMC_MODE(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 | 
|  | * @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, int cs, | 
|  | struct atmel_smc_cs_conf *conf) | 
|  | { | 
|  | regmap_read(regmap, ATMEL_HSMC_SETUP(cs), &conf->setup); | 
|  | regmap_read(regmap, ATMEL_HSMC_PULSE(cs), &conf->pulse); | 
|  | regmap_read(regmap, ATMEL_HSMC_CYCLE(cs), &conf->cycle); | 
|  | regmap_read(regmap, ATMEL_HSMC_TIMINGS(cs), &conf->timings); | 
|  | regmap_read(regmap, ATMEL_HSMC_MODE(cs), &conf->mode); | 
|  | } | 
|  | EXPORT_SYMBOL_GPL(atmel_hsmc_cs_conf_get); |