[U-Boot] [PATCH 4/8] spl: nand: sunxi: Enhancements and cleaning

[Boris Brezillon <boris.brezillon@free-electrons.com>]

On Wed, 24 Jan 2018 01:44:50 +0100
Miquel Raynal <miquel.raynal@free-electrons.com> wrote:

> Do some cleaning in sunxi NAND SPL driver like adding helpers and
> clearing flags at the right spot
> 
> Signed-off-by: Miquel Raynal <miquel.raynal@free-electrons.com>
> ---
>  drivers/mtd/nand/sunxi_nand_spl.c | 64 +++++++++++++++++++++++++--------------
>  1 file changed, 41 insertions(+), 23 deletions(-)
> 
> diff --git a/drivers/mtd/nand/sunxi_nand_spl.c b/drivers/mtd/nand/sunxi_nand_spl.c
> index 06695fc15f..2488d5cb51 100644
> --- a/drivers/mtd/nand/sunxi_nand_spl.c
> +++ b/drivers/mtd/nand/sunxi_nand_spl.c
> @@ -55,8 +55,8 @@
>  
>  
>  #define NFC_ADDR_NUM_OFFSET        16
> -#define NFC_SEND_ADR               (1 << 19)
>  #define NFC_ACCESS_DIR             (1 << 20)
> +#define NFC_SEND_ADDR              (1 << 19)

This typo fix probably deserves a separate patch.

>  #define NFC_DATA_TRANS             (1 << 21)
>  #define NFC_SEND_CMD1              (1 << 22)
>  #define NFC_WAIT_FLAG              (1 << 23)
> @@ -155,6 +155,30 @@ static inline int check_value_negated(int offset, int unexpected_bits,
>  	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;
> +	}
> +
> +	udelay(1);

I'm pretty sure this udelay() is not required. Probably some leftover
of your debug session ;-).

> +
> +	return 0;
> +}
> +
>  void nand_init(void)
>  {
>  	uint32_t val;
> @@ -172,22 +196,21 @@ void nand_init(void)
>  	}
>  
>  	/* reset NAND */
> +	nand_wait_cmd_fifo_empty();
> +
>  	writel(NFC_ST_CMD_INT_FLAG, SUNXI_NFC_BASE + NFC_ST);
>  	writel(NFC_SEND_CMD1 | NFC_WAIT_FLAG | NAND_CMD_RESET,
>  	       SUNXI_NFC_BASE + NFC_CMD);
>  
> -	if (!check_value(SUNXI_NFC_BASE + NFC_ST, NFC_ST_CMD_INT_FLAG,
> -			 DEFAULT_TIMEOUT_US)) {
> -		printf("Error timeout waiting for nand reset\n");
> -		return;
> -	}
> -	writel(NFC_ST_CMD_INT_FLAG, SUNXI_NFC_BASE + NFC_ST);
> +	nand_wait_int();

I would go even further and create an helper that takes care of the
'wait_fifo_empty+clear_int+write_cmd+wait_int' sequence:

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();
}

>  }
>  
>  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),
> @@ -200,6 +223,8 @@ static int nand_load_page(const struct nfc_config *conf, u32 offs)
>  {
>  	int page = offs / conf->page_size;
>  
> +	nand_wait_cmd_fifo_empty();
> +
>  	writel((NFC_CMD_RNDOUTSTART << NFC_RANDOM_READ_CMD1_OFFSET) |
>  	       (NFC_CMD_RNDOUT << NFC_RANDOM_READ_CMD0_OFFSET) |
>  	       (NFC_CMD_READSTART << NFC_READ_CMD_OFFSET),
> @@ -208,38 +233,32 @@ static int nand_load_page(const struct nfc_config *conf, u32 offs)
>  	writel((page >> 16) & 0xFF, SUNXI_NFC_BASE + NFC_ADDR_HIGH);
>  	writel(NFC_ST_CMD_INT_FLAG, SUNXI_NFC_BASE + NFC_ST);
>  	writel(NFC_SEND_CMD1 | NFC_SEND_CMD2 | NFC_RAW_CMD | NFC_WAIT_FLAG |
> -	       ((conf->addr_cycles - 1) << NFC_ADDR_NUM_OFFSET) | NFC_SEND_ADR,
> +	       ((conf->addr_cycles - 1) << NFC_ADDR_NUM_OFFSET) | NFC_SEND_ADDR,
>  	       SUNXI_NFC_BASE + NFC_CMD);
>  
> -	if (!check_value(SUNXI_NFC_BASE + NFC_ST, NFC_ST_CMD_INT_FLAG,
> -			 DEFAULT_TIMEOUT_US)) {
> -		printf("Error while initializing dma interrupt\n");
> -		return -EIO;
> -	}
> -
> -	return 0;
> +	return nand_wait_int();
>  }
>  
>  static int nand_reset_column(void)
>  {
> +	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(0, SUNXI_NFC_BASE + NFC_ADDR_LOW);
>  	writel(NFC_SEND_CMD1 | NFC_SEND_CMD2 | NFC_RAW_CMD |
> -	       (1 << NFC_ADDR_NUM_OFFSET) | NFC_SEND_ADR | NFC_CMD_RNDOUT,
> +	       (1 << NFC_ADDR_NUM_OFFSET) | NFC_SEND_ADDR | NFC_CMD_RNDOUT,
>  	       SUNXI_NFC_BASE + NFC_CMD);
>  
> -	if (!check_value(SUNXI_NFC_BASE + NFC_ST, NFC_ST_CMD_INT_FLAG,
> -			 DEFAULT_TIMEOUT_US)) {
> -		printf("Error while initializing dma interrupt\n");
> -		return -1;
> -	}
> +	return nand_wait_int();

Here, I think you should wait, just to make sure we don't read data
before tCCS. udelay(1) should be enough.

>  
> -	return 0;
>  }
>  
> +static const int ecc_bytes[] = {32, 46, 54, 60, 74, 88, 102, 110, 116};
> +

Putting ecc_bytes out of nand_max_ecc_strength() is not really related
to this patch, and should probably go in patch 5.

>  static int nand_read_page(const struct nfc_config *conf, u32 offs,
>  			  void *dest, int len)
>  {
> @@ -327,7 +346,6 @@ static int nand_read_page(const struct nfc_config *conf, u32 offs,
>  
>  static int nand_max_ecc_strength(struct nfc_config *conf)
>  {
> -	static const int ecc_bytes[] = { 32, 46, 54, 60, 74, 88, 102, 110, 116 };
>  	int max_oobsize, max_ecc_bytes;
>  	int nsectors = conf->page_size / conf->ecc_size;
>  	int i;