// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (c) 2014-2015, Antmicro Ltd <www.antmicro.com>
* Copyright (c) 2015, AW-SOM Technologies <www.aw-som.com>
*/
#include <asm/arch/clock.h>
#include <asm/io.h>
#include <common.h>
#include <config.h>
#include <nand.h>
#include <linux/ctype.h>
/* registers */
#define NFC_CTL 0x00000000
#define NFC_ST 0x00000004
#define NFC_INT 0x00000008
#define NFC_TIMING_CTL 0x0000000C
#define NFC_TIMING_CFG 0x00000010
#define NFC_ADDR_LOW 0x00000014
#define NFC_ADDR_HIGH 0x00000018
#define NFC_SECTOR_NUM 0x0000001C
#define NFC_CNT 0x00000020
#define NFC_CMD 0x00000024
#define NFC_RCMD_SET 0x00000028
#define NFC_WCMD_SET 0x0000002C
#define NFC_IO_DATA 0x00000030
#define NFC_ECC_CTL 0x00000034
#define NFC_ECC_ST 0x00000038
#define NFC_DEBUG 0x0000003C
#define NFC_ECC_CNT0 0x00000040
#define NFC_ECC_CNT1 0x00000044
#define NFC_ECC_CNT2 0x00000048
#define NFC_ECC_CNT3 0x0000004C
#define NFC_USER_DATA_BASE 0x00000050
#define NFC_EFNAND_STATUS 0x00000090
#define NFC_SPARE_AREA 0x000000A0
#define NFC_PATTERN_ID 0x000000A4
#define NFC_RAM0_BASE 0x00000400
#define NFC_RAM1_BASE 0x00000800
#define NFC_CTL_EN (1 << 0)
#define NFC_CTL_RESET (1 << 1)
#define NFC_CTL_RAM_METHOD (1 << 14)
#define NFC_CTL_PAGE_SIZE_MASK (0xf << 8)
#define NFC_CTL_PAGE_SIZE(a) ((fls(a) - 11) << 8)
#define NFC_ECC_EN (1 << 0)
#define NFC_ECC_PIPELINE (1 << 3)
#define NFC_ECC_EXCEPTION (1 << 4)
#define NFC_ECC_BLOCK_SIZE (1 << 5)
#define NFC_ECC_RANDOM_EN (1 << 9)
#define NFC_ECC_RANDOM_DIRECTION (1 << 10)
#define NFC_ADDR_NUM_OFFSET 16
#define NFC_SEND_ADDR (1 << 19)
#define NFC_ACCESS_DIR (1 << 20)
#define NFC_DATA_TRANS (1 << 21)
#define NFC_SEND_CMD1 (1 << 22)
#define NFC_WAIT_FLAG (1 << 23)
#define NFC_SEND_CMD2 (1 << 24)
#define NFC_SEQ (1 << 25)
#define NFC_DATA_SWAP_METHOD (1 << 26)
#define NFC_ROW_AUTO_INC (1 << 27)
#define NFC_SEND_CMD3 (1 << 28)
#define NFC_SEND_CMD4 (1 << 29)
#define NFC_RAW_CMD (0 << 30)
#define NFC_ECC_CMD (1 << 30)
#define NFC_PAGE_CMD (2 << 30)
#define NFC_ST_CMD_INT_FLAG (1 << 1)
#define NFC_ST_DMA_INT_FLAG (1 << 2)
#define NFC_ST_CMD_FIFO_STAT (1 << 3)
#define NFC_READ_CMD_OFFSET 0
#define NFC_RANDOM_READ_CMD0_OFFSET 8
#define NFC_RANDOM_READ_CMD1_OFFSET 16
#define NFC_CMD_RNDOUTSTART 0xE0
#define NFC_CMD_RNDOUT 0x05
#define NFC_CMD_READSTART 0x30
struct nfc_config {
int page_size;
int ecc_strength;
int ecc_size;
int addr_cycles;
int nseeds;
bool randomize;
bool valid;
};
/* minimal "boot0" style NAND support for Allwinner A20 */
/* random seed used by linux */
const uint16_t random_seed[128] = {
0x2b75, 0x0bd0, 0x5ca3, 0x62d1, 0x1c93, 0x07e9, 0x2162, 0x3a72,
0x0d67, 0x67f9, 0x1be7, 0x077d, 0x032f, 0x0dac, 0x2716, 0x2436,
0x7922, 0x1510, 0x3860, 0x5287, 0x480f, 0x4252, 0x1789, 0x5a2d,
0x2a49, 0x5e10, 0x437f, 0x4b4e, 0x2f45, 0x216e, 0x5cb7, 0x7130,
0x2a3f, 0x60e4, 0x4dc9, 0x0ef0, 0x0f52, 0x1bb9, 0x6211, 0x7a56,
0x226d, 0x4ea7, 0x6f36, 0x3692, 0x38bf, 0x0c62, 0x05eb, 0x4c55,
0x60f4, 0x728c, 0x3b6f, 0x2037, 0x7f69, 0x0936, 0x651a, 0x4ceb,
0x6218, 0x79f3, 0x383f, 0x18d9, 0x4f05, 0x5c82, 0x2912, 0x6f17,
0x6856, 0x5938, 0x1007, 0x61ab, 0x3e7f, 0x57c2, 0x542f, 0x4f62,
0x7454, 0x2eac, 0x7739, 0x42d4, 0x2f90, 0x435a, 0x2e52, 0x2064,
0x637c, 0x66ad, 0x2c90, 0x0bad, 0x759c, 0x0029, 0x0986, 0x7126,
0x1ca7, 0x1605, 0x386a, 0x27f5, 0x1380, 0x6d75, 0x24c3, 0x0f8e,
0x2b7a, 0x1418, 0x1fd1, 0x7dc1, 0x2d8e, 0x43af, 0x2267, 0x7da3,
0x4e3d, 0x1338, 0x50db, 0x454d, 0x764d, 0x40a3, 0x42e6, 0x262b,
0x2d2e, 0x1aea, 0x2e17, 0x173d, 0x3a6e, 0x71bf, 0x25f9, 0x0a5d,
0x7c57, 0x0fbe, 0x46ce, 0x4939, 0x6b17, 0x37bb, 0x3e91, 0x76db,
};
#define DEFAULT_TIMEOUT_US 100000
static int check_value_inner(int offset, int expected_bits,
int timeout_us, int negation)
{
do {
int val = readl(offset) & expected_bits;
if (negation ? !val : val)
return 1;
udelay(1);
} while (--timeout_us);
return 0;
}
static inline int check_value(int offset, int expected_bits,
int timeout_us)
{
return check_value_inner(offset, expected_bits, timeout_us, 0);
}
static inline int check_value_negated(int offset, int unexpected_bits,
int timeout_us)
{
return check_value_inner(offset, unexpected_bits, timeout_us, 1);
}
static int nand_wait_cmd_fifo_empty(void)
{
if (!check_value_negated(SUNXI_NFC_BASE + NFC_ST, NFC_ST_CMD_FIFO_STAT,
DEFAULT_TIMEOUT_US)) {
printf("nand: timeout waiting for empty cmd FIFO\n");
return -ETIMEDOUT;
}
return 0;
}
static int nand_wait_int(void)
{
if (!check_value(SUNXI_NFC_BASE + NFC_ST, NFC_ST_CMD_INT_FLAG,
DEFAULT_TIMEOUT_US)) {
printf("nand: timeout waiting for interruption\n");
return -ETIMEDOUT;
}
return 0;
}
static int nand_exec_cmd(u32 cmd)
{
int ret;
ret = nand_wait_cmd_fifo_empty();
if (ret)
return ret;
writel(NFC_ST_CMD_INT_FLAG, SUNXI_NFC_BASE + NFC_ST);
writel(cmd, SUNXI_NFC_BASE + NFC_CMD);
return nand_wait_int();
}
void nand_init(void)
{
uint32_t val;
board_nand_init();
val = readl(SUNXI_NFC_BASE + NFC_CTL);
/* enable and reset CTL */
writel(val | NFC_CTL_EN | NFC_CTL_RESET,
SUNXI_NFC_BASE + NFC_CTL);
if (!check_value_negated(SUNXI_NFC_BASE + NFC_CTL,
NFC_CTL_RESET, DEFAULT_TIMEOUT_US)) {
printf("Couldn't initialize nand\n");
}
/* reset NAND */
nand_exec_cmd(NFC_SEND_CMD1 | NFC_WAIT_FLAG | NAND_CMD_RESET);
}
static void nand_apply_config(const struct nfc_config *conf)
{
u32 val;
nand_wait_cmd_fifo_empty();
val = readl(SUNXI_NFC_BASE + NFC_CTL);
val &= ~NFC_CTL_PAGE_SIZE_MASK;
writel(val | NFC_CTL_RAM_METHOD | NFC_CTL_PAGE_SIZE(conf->page_size),
SUNXI_NFC_BASE + NFC_CTL);
writel(conf->ecc_size, SUNXI_NFC_BASE + NFC_CNT);
writel(conf->page_size, SUNXI_NFC_BASE + NFC_SPARE_AREA);
}
static int nand_load_page(const struct nfc_config *conf, u32 offs)
{
int page = offs / conf->page_size;
writel((NFC_CMD_RNDOUTSTART << NFC_RANDOM_READ_CMD1_OFFSET) |
(NFC_CMD_RNDOUT << NFC_RANDOM_READ_CMD0_OFFSET) |
(NFC_CMD_READSTART << NFC_READ_CMD_OFFSET),
SUNXI_NFC_BASE + NFC_RCMD_SET);
writel(((page & 0xFFFF) << 16), SUNXI_NFC_BASE + NFC_ADDR_LOW);
writel((page >> 16) & 0xFF, SUNXI_NFC_BASE + NFC_ADDR_HIGH);
return nand_exec_cmd(NFC_SEND_CMD1 | NFC_SEND_CMD2 | NFC_RAW_CMD |
NFC_SEND_ADDR | NFC_WAIT_FLAG |
((conf->addr_cycles - 1) << NFC_ADDR_NUM_OFFSET));
}
static int nand_change_column(u16 column)
{
int ret;
writel((NFC_CMD_RNDOUTSTART << NFC_RANDOM_READ_CMD1_OFFSET) |
(NFC_CMD_RNDOUT << NFC_RANDOM_READ_CMD0_OFFSET) |
(NFC_CMD_RNDOUTSTART << NFC_READ_CMD_OFFSET),
SUNXI_NFC_BASE + NFC_RCMD_SET);
writel(column, SUNXI_NFC_BASE + NFC_ADDR_LOW);
ret = nand_exec_cmd(NFC_SEND_CMD1 | NFC_SEND_CMD2 | NFC_RAW_CMD |
(1 << NFC_ADDR_NUM_OFFSET) | NFC_SEND_ADDR |
NFC_CMD_RNDOUT);
if (ret)
return ret;
/* Ensure tCCS has passed before reading data */
udelay(1);
return 0;
}
static const int ecc_bytes[] = {32, 46, 54, 60, 74, 88, 102, 110, 116};
static int nand_read_page(const struct nfc_config *conf, u32 offs,
void *dest, int len)
{
int nsectors = len / conf->ecc_size;
u16 rand_seed = 0;
int oob_chunk_sz = ecc_bytes[conf->ecc_strength];
int page = offs / conf->page_size;
u32 ecc_st;
int i;
if (offs % conf->page_size || len % conf->ecc_size ||
len > conf->page_size || len < 0)
return -EINVAL;
/* Choose correct seed if randomized */
if (conf->randomize)
rand_seed = random_seed[page % conf->nseeds];
/* Retrieve data from SRAM (PIO) */
for (i = 0; i < nsectors; i++) {
int data_off = i * conf->ecc_size;
int oob_off = conf->page_size + (i * oob_chunk_sz);
u8 *data = dest + data_off;
/* Clear ECC status and restart ECC engine */
writel(0, SUNXI_NFC_BASE + NFC_ECC_ST);
writel((rand_seed << 16) | (conf->ecc_strength << 12) |
(conf->randomize ? NFC_ECC_RANDOM_EN : 0) |
(conf->ecc_size == 512 ? NFC_ECC_BLOCK_SIZE : 0) |
NFC_ECC_EN | NFC_ECC_EXCEPTION,
SUNXI_NFC_BASE + NFC_ECC_CTL);
/* Move the data in SRAM */
nand_change_column(data_off);
writel(conf->ecc_size, SUNXI_NFC_BASE + NFC_CNT);
nand_exec_cmd(NFC_DATA_TRANS);
/*
* Let the ECC engine consume the ECC bytes and possibly correct
* the data.
*/
nand_change_column(oob_off);
nand_exec_cmd(NFC_DATA_TRANS | NFC_ECC_CMD);
/* Get the ECC status */
ecc_st = readl(SUNXI_NFC_BASE + NFC_ECC_ST);
/* ECC error detected. */
if (ecc_st & 0xffff)
return -EIO;
/*
* Return 1 if the first chunk is empty (needed for
* configuration detection).
*/
if (!i && (ecc_st & 0x10000))
return 1;
/* Retrieve the data from SRAM */
memcpy_fromio(data, SUNXI_NFC_BASE + NFC_RAM0_BASE,
conf->ecc_size);
/* Stop the ECC engine */
writel(readl(SUNXI_NFC_BASE + NFC_ECC_CTL) & ~NFC_ECC_EN,
SUNXI_NFC_BASE + NFC_ECC_CTL);
if (data_off + conf->ecc_size >= len)
break;
}
return 0;
}
static int nand_max_ecc_strength(struct nfc_config *conf)
{
int max_oobsize, max_ecc_bytes;
int nsectors = conf->page_size / conf->ecc_size;
int i;
/*
* ECC strength is limited by the size of the OOB area which is
* correlated with the page size.
*/
switch (conf->page_size) {
case 2048:
max_oobsize = 64;
break;
case 4096:
max_oobsize = 256;
break;
case 8192:
max_oobsize = 640;
break;
case 16384:
max_oobsize = 1664;
break;
default:
return -EINVAL;
}
max_ecc_bytes = max_oobsize / nsectors;
for (i = 0; i < ARRAY_SIZE(ecc_bytes); i++) {
if (ecc_bytes[i] > max_ecc_bytes)
break;
}
if (!i)
return -EINVAL;
return i - 1;
}
static int nand_detect_ecc_config(struct nfc_config *conf, u32 offs,
void *dest)
{
/* NAND with pages > 4k will likely require 1k sector size. */
int min_ecc_size = conf->page_size > 4096 ? 1024 : 512;
int page = offs / conf->page_size;
int ret;
/*
* In most cases, 1k sectors are preferred over 512b ones, start
* testing this config first.
*/
for (conf->ecc_size = 1024; conf->ecc_size >= min_ecc_size;
conf->ecc_size >>= 1) {
int max_ecc_strength = nand_max_ecc_strength(conf);
nand_apply_config(conf);
/*
* We are starting from the maximum ECC strength because
* most of the time NAND vendors provide an OOB area that
* barely meets the ECC requirements.
*/
for (conf->ecc_strength = max_ecc_strength;
conf->ecc_strength >= 0;
conf->ecc_strength--) {
conf->randomize = false;
if (nand_change_column(0))
return -EIO;
/*
* Only read the first sector to speedup detection.
*/
ret = nand_read_page(conf, offs, dest, conf->ecc_size);
if (!ret) {
return 0;
} else if (ret > 0) {
/*
* If page is empty we can't deduce anything
* about the ECC config => stop the detection.
*/
return -EINVAL;
}
conf->randomize = true;
conf->nseeds = ARRAY_SIZE(random_seed);
do {
if (nand_change_column(0))
return -EIO;
if (!nand_read_page(conf, offs, dest,
conf->ecc_size))
return 0;
/*
* Find the next ->nseeds value that would
* change the randomizer seed for the page
* we're trying to read.
*/
while (conf->nseeds >= 16) {
int seed = page % conf->nseeds;
conf->nseeds >>= 1;
if (seed != page % conf->nseeds)
break;
}
} while (conf->nseeds >= 16);
}
}
return -EINVAL;
}
static int nand_detect_config(struct nfc_config *conf, u32 offs, void *dest)
{
if (conf->valid)
return 0;
/*
* Modern NANDs are more likely than legacy ones, so we start testing
* with 5 address cycles.
*/
for (conf->addr_cycles = 5;
conf->addr_cycles >= 4;
conf->addr_cycles--) {
int max_page_size = conf->addr_cycles == 4 ? 2048 : 16384;
/*
* Ignoring 1k pages cause I'm not even sure this case exist
* in the real world.
*/
for (conf->page_size = 2048; conf->page_size <= max_page_size;
conf->page_size <<= 1) {
if (nand_load_page(conf, offs))
return -1;
if (!nand_detect_ecc_config(conf, offs, dest)) {
conf->valid = true;
return 0;
}
}
}
return -EINVAL;
}
static int nand_read_buffer(struct nfc_config *conf, uint32_t offs,
unsigned int size, void *dest)
{
int first_seed = 0, page, ret;
size = ALIGN(size, conf->page_size);
page = offs / conf->page_size;
if (conf->randomize)
first_seed = page % conf->nseeds;
for (; size; size -= conf->page_size) {
if (nand_load_page(conf, offs))
return -1;
ret = nand_read_page(conf, offs, dest, conf->page_size);
/*
* The ->nseeds value should be equal to the number of pages
* in an eraseblock. Since we don't know this information in
* advance we might have picked a wrong value.
*/
if (ret < 0 && conf->randomize) {
int cur_seed = page % conf->nseeds;
/*
* We already tried all the seed values => we are
* facing a real corruption.
*/
if (cur_seed < first_seed)
return -EIO;
/* Try to adjust ->nseeds and read the page again... */
conf->nseeds = cur_seed;
if (nand_change_column(0))
return -EIO;
/* ... it still fails => it's a real corruption. */
if (nand_read_page(conf, offs, dest, conf->page_size))
return -EIO;
} else if (ret && conf->randomize) {
memset(dest, 0xff, conf->page_size);
}
page++;
offs += conf->page_size;
dest += conf->page_size;
}
return 0;
}
int nand_spl_load_image(uint32_t offs, unsigned int size, void *dest)
{
static struct nfc_config conf = { };
int ret;
ret = nand_detect_config(&conf, offs, dest);
if (ret)
return ret;
return nand_read_buffer(&conf, offs, size, dest);
}
void nand_deselect(void)
{
struct sunxi_ccm_reg *const ccm =
(struct sunxi_ccm_reg *)SUNXI_CCM_BASE;
clrbits_le32(&ccm->ahb_gate0, (CLK_GATE_OPEN << AHB_GATE_OFFSET_NAND0));
#ifdef CONFIG_MACH_SUN9I
clrbits_le32(&ccm->ahb_gate1, (1 << AHB_GATE_OFFSET_DMA));
#else
clrbits_le32(&ccm->ahb_gate0, (1 << AHB_GATE_OFFSET_DMA));
#endif
clrbits_le32(&ccm->nand0_clk_cfg, CCM_NAND_CTRL_ENABLE | AHB_DIV_1);
}