[U-Boot] [PATCH 5/8] spl: nand: sunxi: use PIO instead of DMA
Maxime Ripard
maxime.ripard at free-electrons.com
Wed Jan 24 08:06:26 UTC 2018
Hi,
On Wed, Jan 24, 2018 at 01:44:51AM +0100, Miquel Raynal wrote:
> Because using DMA implementation is not generic and was not developped
> to work on SoCs like A33, migrate the SPL to use PIO.
>
> Signed-off-by: Miquel Raynal <miquel.raynal at free-electrons.com>
I guess the issue is slightly different than what you're saying, or at
least should be expressed differently.
The issue is that the SPL support has be done to support only the
earlier generations of Allwinner SoCs, and only really enabled on the
A13 / GR8. However, those old SoCs had a DMA engine that has been
replaced since the A31 by another DMA controller that is no longer
compatible.
Since the code directly uses that DMA controller, it cannot operate
properly on the later SoCs, while the NAND controller hasn't changed.
There's two pathes forward, the first one would be to add support for
that DMA controller too, or you can just remove the DMA usage entirely
and rely on PIO that will make the driver simpler.
Explaining why you chose PIO would be great too.
> ---
> board/sunxi/board.c | 4 +-
> drivers/mtd/nand/sunxi_nand_spl.c | 167 +++++++++++++++++---------------------
> 2 files changed, 79 insertions(+), 92 deletions(-)
>
> diff --git a/board/sunxi/board.c b/board/sunxi/board.c
> index 70e01437c4..512e2c17a6 100644
> --- a/board/sunxi/board.c
> +++ b/board/sunxi/board.c
> @@ -266,11 +266,13 @@ static void nand_clock_setup(void)
> struct sunxi_ccm_reg *const ccm =
> (struct sunxi_ccm_reg *)SUNXI_CCM_BASE;
>
> - setbits_le32(&ccm->ahb_gate0, (CLK_GATE_OPEN << AHB_GATE_OFFSET_NAND0));
> + setbits_le32(&ccm->ahb_gate0, (1 << AHB_GATE_OFFSET_NAND0));
> + setbits_le32(&ccm->ahb_reset0_cfg, (1 << AHB_GATE_OFFSET_NAND0));
That has nothing to do with PIO vs DMA. It should be in another patch.
> #ifdef CONFIG_MACH_SUN9I
> setbits_le32(&ccm->ahb_gate1, (1 << AHB_GATE_OFFSET_DMA));
> #else
> setbits_le32(&ccm->ahb_gate0, (1 << AHB_GATE_OFFSET_DMA));
> + setbits_le32(&ccm->ahb_reset0_cfg, (1 << AHB_GATE_OFFSET_DMA));
So you're de-asserting the reset line for the DMA controller, while
the commit is about removing the need for that DMA controller ? :)
That whole block can actually be removed (in a separate patch) now
that you're not using DMA anymore.
> #endif
> setbits_le32(&ccm->nand0_clk_cfg, CCM_NAND_CTRL_ENABLE | AHB_DIV_1);
> }
> diff --git a/drivers/mtd/nand/sunxi_nand_spl.c b/drivers/mtd/nand/sunxi_nand_spl.c
> index 2488d5cb51..5de6825994 100644
> --- a/drivers/mtd/nand/sunxi_nand_spl.c
> +++ b/drivers/mtd/nand/sunxi_nand_spl.c
> @@ -10,6 +10,7 @@
> #include <common.h>
> #include <config.h>
> #include <nand.h>
> +#include <linux/ctype.h>
>
> /* registers */
> #define NFC_CTL 0x00000000
> @@ -45,32 +46,22 @@
> #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_ACCESS_DIR (1 << 20)
> #define NFC_SEND_ADDR (1 << 19)
> #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_PAGE_CMD (2 << 30)
> +#define NFC_ECC_CMD (1 << 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
> @@ -80,22 +71,6 @@
> #define NFC_CMD_RNDOUT 0x05
> #define NFC_CMD_READSTART 0x30
>
> -#define SUNXI_DMA_CFG_REG0 0x300
> -#define SUNXI_DMA_SRC_START_ADDR_REG0 0x304
> -#define SUNXI_DMA_DEST_START_ADDRR_REG0 0x308
> -#define SUNXI_DMA_DDMA_BC_REG0 0x30C
> -#define SUNXI_DMA_DDMA_PARA_REG0 0x318
> -
> -#define SUNXI_DMA_DDMA_CFG_REG_LOADING (1 << 31)
> -#define SUNXI_DMA_DDMA_CFG_REG_DMA_DEST_DATA_WIDTH_32 (2 << 25)
> -#define SUNXI_DMA_DDMA_CFG_REG_DDMA_DST_DRQ_TYPE_DRAM (1 << 16)
> -#define SUNXI_DMA_DDMA_CFG_REG_DMA_SRC_DATA_WIDTH_32 (2 << 9)
> -#define SUNXI_DMA_DDMA_CFG_REG_DMA_SRC_ADDR_MODE_IO (1 << 5)
> -#define SUNXI_DMA_DDMA_CFG_REG_DDMA_SRC_DRQ_TYPE_NFC (3 << 0)
> -
> -#define SUNXI_DMA_DDMA_PARA_REG_SRC_WAIT_CYC (0x0F << 0)
> -#define SUNXI_DMA_DDMA_PARA_REG_SRC_BLK_SIZE (0x7F << 8)
> -
We should probably keep those values. They're not used anymore, but
the NAND controller has been under-documented on most of the datasheet
we've had. It's good to keep it at least for reference.
> struct nfc_config {
> int page_size;
> int ecc_strength;
> @@ -254,7 +229,23 @@ static int nand_reset_column(void)
> SUNXI_NFC_BASE + NFC_CMD);
>
> return nand_wait_int();
> +}
>
> +static int nand_change_column(u16 column)
> +{
> + nand_wait_cmd_fifo_empty();
> +
> + 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(NFC_ST_CMD_INT_FLAG, SUNXI_NFC_BASE + NFC_ST);
> + writel(column, SUNXI_NFC_BASE + NFC_ADDR_LOW);
> + writel(NFC_SEND_CMD1 | NFC_SEND_CMD2 | NFC_RAW_CMD |
> + (1 << NFC_ADDR_NUM_OFFSET) | NFC_SEND_ADDR | NFC_CMD_RNDOUT,
> + SUNXI_NFC_BASE + NFC_CMD);
> +
> + return nand_wait_int();
> }
>
> static const int ecc_bytes[] = {32, 46, 54, 60, 74, 88, 102, 110, 116};
> @@ -262,86 +253,80 @@ 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)
> {
> - dma_addr_t dst = (dma_addr_t)dest;
> int nsectors = len / conf->ecc_size;
> u16 rand_seed = 0;
> - u32 val;
> - int page;
> -
> - page = offs / conf->page_size;
> + 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;
>
> - /* clear ecc status */
> - writel(0, SUNXI_NFC_BASE + NFC_ECC_ST);
> -
> /* Choose correct seed if randomized */
> if (conf->randomize)
> rand_seed = random_seed[page % conf->nseeds];
>
> - 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_PIPELINE | NFC_ECC_EXCEPTION,
> - SUNXI_NFC_BASE + NFC_ECC_CTL);
> -
> - flush_dcache_range(dst, ALIGN(dst + conf->ecc_size, ARCH_DMA_MINALIGN));
> -
> - /* SUNXI_DMA */
> - writel(0x0, SUNXI_DMA_BASE + SUNXI_DMA_CFG_REG0); /* clr dma cmd */
> - /* read from REG_IO_DATA */
> - writel(SUNXI_NFC_BASE + NFC_IO_DATA,
> - SUNXI_DMA_BASE + SUNXI_DMA_SRC_START_ADDR_REG0);
> - /* read to RAM */
> - writel(dst, SUNXI_DMA_BASE + SUNXI_DMA_DEST_START_ADDRR_REG0);
> - writel(SUNXI_DMA_DDMA_PARA_REG_SRC_WAIT_CYC |
> - SUNXI_DMA_DDMA_PARA_REG_SRC_BLK_SIZE,
> - SUNXI_DMA_BASE + SUNXI_DMA_DDMA_PARA_REG0);
> - writel(len, SUNXI_DMA_BASE + SUNXI_DMA_DDMA_BC_REG0);
> - writel(SUNXI_DMA_DDMA_CFG_REG_LOADING |
> - SUNXI_DMA_DDMA_CFG_REG_DMA_DEST_DATA_WIDTH_32 |
> - SUNXI_DMA_DDMA_CFG_REG_DDMA_DST_DRQ_TYPE_DRAM |
> - SUNXI_DMA_DDMA_CFG_REG_DMA_SRC_DATA_WIDTH_32 |
> - SUNXI_DMA_DDMA_CFG_REG_DMA_SRC_ADDR_MODE_IO |
> - SUNXI_DMA_DDMA_CFG_REG_DDMA_SRC_DRQ_TYPE_NFC,
> - SUNXI_DMA_BASE + SUNXI_DMA_CFG_REG0);
> -
> - writel(nsectors, SUNXI_NFC_BASE + NFC_SECTOR_NUM);
> - writel(NFC_ST_DMA_INT_FLAG, SUNXI_NFC_BASE + NFC_ST);
> - writel(NFC_DATA_TRANS | NFC_PAGE_CMD | NFC_DATA_SWAP_METHOD,
> - SUNXI_NFC_BASE + NFC_CMD);
> + /* 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);
> + nand_wait_cmd_fifo_empty();
> + writel(NFC_ST_CMD_INT_FLAG, SUNXI_NFC_BASE + NFC_ST);
> + writel(conf->ecc_size, SUNXI_NFC_BASE + NFC_CNT);
> + writel(NFC_DATA_TRANS, SUNXI_NFC_BASE + NFC_CMD);
> + nand_wait_int();
>
> - if (!check_value(SUNXI_NFC_BASE + NFC_ST, NFC_ST_DMA_INT_FLAG,
> - DEFAULT_TIMEOUT_US)) {
> - printf("Error while initializing dma interrupt\n");
> - return -EIO;
> - }
> - writel(NFC_ST_DMA_INT_FLAG, SUNXI_NFC_BASE + NFC_ST);
It seems that you're also converting this code to some of your new
helpers. This should be done in the patch introducing them.
> + /*
> + * Let the ECC engine consume the ECC bytes and possibly correct
> + * the data.
> + */
> + nand_change_column(oob_off);
> + nand_wait_cmd_fifo_empty();
> + writel(NFC_ST_CMD_INT_FLAG, SUNXI_NFC_BASE + NFC_ST);
> + writel(NFC_DATA_TRANS | NFC_ECC_CMD, SUNXI_NFC_BASE + NFC_CMD);
> + nand_wait_int();
>
> - if (!check_value_negated(SUNXI_DMA_BASE + SUNXI_DMA_CFG_REG0,
> - SUNXI_DMA_DDMA_CFG_REG_LOADING,
> - DEFAULT_TIMEOUT_US)) {
> - printf("Error while waiting for dma transfer to finish\n");
> - return -EIO;
> - }
Ditto.
Thanks!
Maxime
--
Maxime Ripard, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 833 bytes
Desc: not available
URL: <http://lists.denx.de/pipermail/u-boot/attachments/20180124/163a0380/attachment.sig>
More information about the U-Boot
mailing list