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Diffstat (limited to 'arch/arm/cpu/armv7/am33xx/elm.c')
| -rw-r--r-- | arch/arm/cpu/armv7/am33xx/elm.c | 212 | 
1 files changed, 212 insertions, 0 deletions
| diff --git a/arch/arm/cpu/armv7/am33xx/elm.c b/arch/arm/cpu/armv7/am33xx/elm.c new file mode 100644 index 000000000..9eed23d75 --- /dev/null +++ b/arch/arm/cpu/armv7/am33xx/elm.c @@ -0,0 +1,212 @@ +/* + * (C) Copyright 2010-2011 Texas Instruments, <www.ti.com> + * Mansoor Ahamed <mansoor.ahamed@ti.com> + * + * BCH Error Location Module (ELM) support. + * + * NOTE: + * 1. Supports only continuous mode. Dont see need for page mode in uboot + * 2. Supports only syndrome polynomial 0. i.e. poly local variable is + *    always set to ELM_DEFAULT_POLY. Dont see need for other polynomial + *    sets in uboot + * + * See file CREDITS for list of people who contributed to this + * project. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ + +#include <common.h> +#include <asm/io.h> +#include <asm/errno.h> +#include <asm/arch/cpu.h> +#include <asm/arch/omap_gpmc.h> +#include <asm/arch/elm.h> + +#define ELM_DEFAULT_POLY (0) + +struct elm *elm_cfg; + +/** + * elm_load_syndromes - Load BCH syndromes based on nibble selection + * @syndrome: BCH syndrome + * @nibbles: + * @poly: Syndrome Polynomial set to use + * + * Load BCH syndromes based on nibble selection + */ +static void elm_load_syndromes(u8 *syndrome, u32 nibbles, u8 poly) +{ +	u32 *ptr; +	u32 val; + +	/* reg 0 */ +	ptr = &elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[0]; +	val = syndrome[0] | (syndrome[1] << 8) | (syndrome[2] << 16) | +				(syndrome[3] << 24); +	writel(val, ptr); +	/* reg 1 */ +	ptr = &elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[1]; +	val = syndrome[4] | (syndrome[5] << 8) | (syndrome[6] << 16) | +				(syndrome[7] << 24); +	writel(val, ptr); + +	/* BCH 8-bit with 26 nibbles (4*8=32) */ +	if (nibbles > 13) { +		/* reg 2 */ +		ptr = &elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[2]; +		val = syndrome[8] | (syndrome[9] << 8) | (syndrome[10] << 16) | +				(syndrome[11] << 24); +		writel(val, ptr); +		/* reg 3 */ +		ptr = &elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[3]; +		val = syndrome[12] | (syndrome[13] << 8) | +			(syndrome[14] << 16) | (syndrome[15] << 24); +		writel(val, ptr); +	} + +	/* BCH 16-bit with 52 nibbles (7*8=56) */ +	if (nibbles > 26) { +		/* reg 4 */ +		ptr = &elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[4]; +		val = syndrome[16] | (syndrome[17] << 8) | +			(syndrome[18] << 16) | (syndrome[19] << 24); +		writel(val, ptr); + +		/* reg 5 */ +		ptr = &elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[5]; +		val = syndrome[20] | (syndrome[21] << 8) | +			(syndrome[22] << 16) | (syndrome[23] << 24); +		writel(val, ptr); + +		/* reg 6 */ +		ptr = &elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[6]; +		val = syndrome[24] | (syndrome[25] << 8) | +			(syndrome[26] << 16) | (syndrome[27] << 24); +		writel(val, ptr); +	} +} + +/** + * elm_check_errors - Check for BCH errors and return error locations + * @syndrome: BCH syndrome + * @nibbles: + * @error_count: Returns number of errrors in the syndrome + * @error_locations: Returns error locations (in decimal) in this array + * + * Check the provided syndrome for BCH errors and return error count + * and locations in the array passed. Returns -1 if error is not correctable, + * else returns 0 + */ +int elm_check_error(u8 *syndrome, u32 nibbles, u32 *error_count, +		u32 *error_locations) +{ +	u8 poly = ELM_DEFAULT_POLY; +	s8 i; +	u32 location_status; + +	elm_load_syndromes(syndrome, nibbles, poly); + +	/* start processing */ +	writel((readl(&elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[6]) +				| ELM_SYNDROME_FRAGMENT_6_SYNDROME_VALID), +		&elm_cfg->syndrome_fragments[poly].syndrome_fragment_x[6]); + +	/* wait for processing to complete */ +	while ((readl(&elm_cfg->irqstatus) & (0x1 << poly)) != 0x1) +		; +	/* clear status */ +	writel((readl(&elm_cfg->irqstatus) | (0x1 << poly)), +			&elm_cfg->irqstatus); + +	/* check if correctable */ +	location_status = readl(&elm_cfg->error_location[poly].location_status); +	if (!(location_status & ELM_LOCATION_STATUS_ECC_CORRECTABLE_MASK)) +		return -1; + +	/* get error count */ +	*error_count = readl(&elm_cfg->error_location[poly].location_status) & +					ELM_LOCATION_STATUS_ECC_NB_ERRORS_MASK; + +	for (i = 0; i < *error_count; i++) { +		error_locations[i] = +			readl(&elm_cfg->error_location[poly].error_location_x[i]); +	} + +	return 0; +} + + +/** + * elm_config - Configure ELM module + * @level: 4 / 8 / 16 bit BCH + * + * Configure ELM module based on BCH level. + * Set mode as continuous mode. + * Currently we are using only syndrome 0 and syndromes 1 to 6 are not used. + * Also, the mode is set only for syndrome 0 + */ +int elm_config(enum bch_level level) +{ +	u32 val; +	u8 poly = ELM_DEFAULT_POLY; +	u32 buffer_size = 0x7FF; + +	/* config size and level */ +	val = (u32)(level) & ELM_LOCATION_CONFIG_ECC_BCH_LEVEL_MASK; +	val |= ((buffer_size << ELM_LOCATION_CONFIG_ECC_SIZE_POS) & +				ELM_LOCATION_CONFIG_ECC_SIZE_MASK); +	writel(val, &elm_cfg->location_config); + +	/* config continous mode */ +	/* enable interrupt generation for syndrome polynomial set */ +	writel((readl(&elm_cfg->irqenable) | (0x1 << poly)), +			&elm_cfg->irqenable); +	/* set continuous mode for the syndrome polynomial set */ +	writel((readl(&elm_cfg->page_ctrl) & ~(0x1 << poly)), +			&elm_cfg->page_ctrl); + +	return 0; +} + +/** + * elm_reset - Do a soft reset of ELM + * + * Perform a soft reset of ELM and return after reset is done. + */ +void elm_reset(void) +{ +	/* initiate reset */ +	writel((readl(&elm_cfg->sysconfig) | ELM_SYSCONFIG_SOFTRESET), +				&elm_cfg->sysconfig); + +	/* wait for reset complete and normal operation */ +	while ((readl(&elm_cfg->sysstatus) & ELM_SYSSTATUS_RESETDONE) != +		ELM_SYSSTATUS_RESETDONE) +		; +} + +/** + * elm_init - Initialize ELM module + * + * Initialize ELM support. Currently it does only base address init + * and ELM reset. + */ +void elm_init(void) +{ +	elm_cfg = (struct elm *)ELM_BASE; +	elm_reset(); +} |