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// SPDX-License-Identifier: GPL-2.0+
/*
* (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
*/
#include <common.h>
#include <asm/io.h>
#include <linux/errno.h>
#include <linux/mtd/omap_elm.h>
#include <asm/arch/hardware.h>
#define DRIVER_NAME "omap-elm"
#define ELM_DEFAULT_POLY (0)
struct elm *elm_cfg;
/**
* elm_load_syndromes - Load BCH syndromes based on bch_type selection
* @syndrome: BCH syndrome
* @bch_type: BCH4/BCH8/BCH16
* @poly: Syndrome Polynomial set to use
*/
static void elm_load_syndromes(u8 *syndrome, enum bch_level bch_type, 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);
if (bch_type == BCH_8_BIT || bch_type == BCH_16_BIT) {
/* 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);
}
if (bch_type == BCH_16_BIT) {
/* 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
* @bch_type: BCH4/BCH8/BCH16
* @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, enum bch_level bch_type, u32 *error_count,
u32 *error_locations)
{
u8 poly = ELM_DEFAULT_POLY;
s8 i;
u32 location_status;
elm_load_syndromes(syndrome, bch_type, 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)) {
printf("%s: uncorrectable ECC errors\n", DRIVER_NAME);
return -EBADMSG;
}
/* 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();
}
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