| /* |
| * 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> |
| |
| /** |
| * 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 |
| * @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); |