u-boot/board/synopsys/axs101/nand.c
Alexey Brodkin 17b0da8019 axs101: flush DMA buffer descriptors before DMA transactons starts
CPU sets DMA buffer descriptors with data required for inetrnal DMA such as:
 * Ownership of BD
 * Buffer size
 * Pointer to data buffer in memory

Then we need to make sure DMA engine of NAND controller gets proper data.
For this we flush buffer rescriptor.

Then we're  ready for DMA transaction.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>

Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Tom Rini <trini@ti.com>
2014-03-28 15:06:30 -04:00

234 lines
5.6 KiB
C

/*
* Copyright (C) 2013-2014 Synopsys, Inc. All rights reserved.
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <bouncebuf.h>
#include <common.h>
#include <malloc.h>
#include <nand.h>
#include <asm/io.h>
#define BUS_WIDTH 8 /* AXI data bus width in bytes */
/* DMA buffer descriptor bits & masks */
#define BD_STAT_OWN (1 << 31)
#define BD_STAT_BD_FIRST (1 << 3)
#define BD_STAT_BD_LAST (1 << 2)
#define BD_SIZES_BUFFER1_MASK 0xfff
#define BD_STAT_BD_COMPLETE (BD_STAT_BD_FIRST | BD_STAT_BD_LAST)
/* Controller command flags */
#define B_WFR (1 << 19) /* 1b - Wait for ready */
#define B_LC (1 << 18) /* 1b - Last cycle */
#define B_IWC (1 << 13) /* 1b - Interrupt when complete */
/* NAND cycle types */
#define B_CT_ADDRESS (0x0 << 16) /* Address operation */
#define B_CT_COMMAND (0x1 << 16) /* Command operation */
#define B_CT_WRITE (0x2 << 16) /* Write operation */
#define B_CT_READ (0x3 << 16) /* Write operation */
enum nand_isr_t {
NAND_ISR_DATAREQUIRED = 0,
NAND_ISR_TXUNDERFLOW,
NAND_ISR_TXOVERFLOW,
NAND_ISR_DATAAVAILABLE,
NAND_ISR_RXUNDERFLOW,
NAND_ISR_RXOVERFLOW,
NAND_ISR_TXDMACOMPLETE,
NAND_ISR_RXDMACOMPLETE,
NAND_ISR_DESCRIPTORUNAVAILABLE,
NAND_ISR_CMDDONE,
NAND_ISR_CMDAVAILABLE,
NAND_ISR_CMDERROR,
NAND_ISR_DATATRANSFEROVER,
NAND_ISR_NONE
};
enum nand_regs_t {
AC_FIFO = 0, /* address and command fifo */
IDMAC_BDADDR = 0x18, /* idmac descriptor list base address */
INT_STATUS = 0x118, /* interrupt status register */
INT_CLR_STATUS = 0x120, /* interrupt clear status register */
};
struct nand_bd {
uint32_t status; /* DES0 */
uint32_t sizes; /* DES1 */
uint32_t buffer_ptr0; /* DES2 */
uint32_t buffer_ptr1; /* DES3 */
};
#define NAND_REG_WRITE(r, v) writel(v, CONFIG_SYS_NAND_BASE + r)
#define NAND_REG_READ(r) readl(CONFIG_SYS_NAND_BASE + r)
static struct nand_bd *bd; /* DMA buffer descriptors */
/**
* axs101_nand_write_buf - write buffer to chip
* @mtd: MTD device structure
* @buf: data buffer
* @len: number of bytes to write
*/
static uint32_t nand_flag_is_set(uint32_t flag)
{
uint32_t reg = NAND_REG_READ(INT_STATUS);
if (reg & (1 << NAND_ISR_CMDERROR))
return 0;
if (reg & (1 << flag)) {
NAND_REG_WRITE(INT_CLR_STATUS, 1 << flag);
return 1;
}
return 0;
}
/**
* axs101_nand_write_buf - write buffer to chip
* @mtd: MTD device structure
* @buf: data buffer
* @len: number of bytes to write
*/
static void axs101_nand_write_buf(struct mtd_info *mtd, const u_char *buf,
int len)
{
struct bounce_buffer bbstate;
bounce_buffer_start(&bbstate, (void *)buf, len, GEN_BB_READ);
/* Setup buffer descriptor */
writel(BD_STAT_OWN | BD_STAT_BD_COMPLETE, &bd->status);
writel(ALIGN(len, BUS_WIDTH) & BD_SIZES_BUFFER1_MASK, &bd->sizes);
writel(bbstate.bounce_buffer, &bd->buffer_ptr0);
writel(0, &bd->buffer_ptr1);
/* Flush modified buffer descriptor */
flush_dcache_range((unsigned long)bd,
(unsigned long)bd + sizeof(struct nand_bd));
/* Issue "write" command */
NAND_REG_WRITE(AC_FIFO, B_CT_WRITE | B_WFR | B_IWC | B_LC | (len-1));
/* Wait for NAND command and DMA to complete */
while (!nand_flag_is_set(NAND_ISR_CMDDONE))
;
while (!nand_flag_is_set(NAND_ISR_TXDMACOMPLETE))
;
bounce_buffer_stop(&bbstate);
}
/**
* axs101_nand_read_buf - read chip data into buffer
* @mtd: MTD device structure
* @buf: buffer to store data
* @len: number of bytes to read
*/
static void axs101_nand_read_buf(struct mtd_info *mtd, u_char *buf, int len)
{
struct bounce_buffer bbstate;
bounce_buffer_start(&bbstate, buf, len, GEN_BB_WRITE);
/* Setup buffer descriptor */
writel(BD_STAT_OWN | BD_STAT_BD_COMPLETE, &bd->status);
writel(ALIGN(len, BUS_WIDTH) & BD_SIZES_BUFFER1_MASK, &bd->sizes);
writel(bbstate.bounce_buffer, &bd->buffer_ptr0);
writel(0, &bd->buffer_ptr1);
/* Flush modified buffer descriptor */
flush_dcache_range((unsigned long)bd,
(unsigned long)bd + sizeof(struct nand_bd));
/* Issue "read" command */
NAND_REG_WRITE(AC_FIFO, B_CT_READ | B_WFR | B_IWC | B_LC | (len - 1));
/* Wait for NAND command and DMA to complete */
while (!nand_flag_is_set(NAND_ISR_CMDDONE))
;
while (!nand_flag_is_set(NAND_ISR_RXDMACOMPLETE))
;
bounce_buffer_stop(&bbstate);
}
/**
* axs101_nand_read_byte - read one byte from the chip
* @mtd: MTD device structure
*/
static u_char axs101_nand_read_byte(struct mtd_info *mtd)
{
u8 byte;
axs101_nand_read_buf(mtd, (uchar *)&byte, sizeof(byte));
return byte;
}
/**
* axs101_nand_read_word - read one word from the chip
* @mtd: MTD device structure
*/
static u16 axs101_nand_read_word(struct mtd_info *mtd)
{
u16 word;
axs101_nand_read_buf(mtd, (uchar *)&word, sizeof(word));
return word;
}
/**
* axs101_nand_hwcontrol - NAND control functions wrapper.
* @mtd: MTD device structure
* @cmd: Command
*/
static void axs101_nand_hwcontrol(struct mtd_info *mtdinfo, int cmd,
unsigned int ctrl)
{
if (cmd == NAND_CMD_NONE)
return;
cmd = cmd & 0xff;
switch (ctrl & (NAND_ALE | NAND_CLE)) {
/* Address */
case NAND_ALE:
cmd |= B_CT_ADDRESS;
break;
/* Command */
case NAND_CLE:
cmd |= B_CT_COMMAND | B_WFR;
break;
default:
debug("%s: unknown ctrl %#x\n", __func__, ctrl);
}
NAND_REG_WRITE(AC_FIFO, cmd | B_LC);
while (!nand_flag_is_set(NAND_ISR_CMDDONE))
;
}
int board_nand_init(struct nand_chip *nand)
{
bd = (struct nand_bd *)memalign(ARCH_DMA_MINALIGN,
sizeof(struct nand_bd));
/* Set buffer descriptor address in IDMAC */
NAND_REG_WRITE(IDMAC_BDADDR, bd);
nand->ecc.mode = NAND_ECC_SOFT;
nand->cmd_ctrl = axs101_nand_hwcontrol;
nand->read_byte = axs101_nand_read_byte;
nand->read_word = axs101_nand_read_word;
nand->write_buf = axs101_nand_write_buf;
nand->read_buf = axs101_nand_read_buf;
return 0;
}