[U-Boot] [PATCH v2 8/9] sunxi: mmc support

[Marek Vasut <marex@denx.de>]

On Friday, March 21, 2014 at 10:54:25 PM, Ian Campbell wrote:
> As well as the following signed-off-by the sunxi branch shows commits to
> these files authored by the following:
>   Stefan Roese
>   Tom Cubie
>   yemao
> 
> Signed-off-by: Henrik Nordstrom <henrik@henriknordstrom.net>
> Signed-off-by: Luke Leighton <lkcl@lkcl.net>
> Signed-off-by: Oliver Schinagl <oliver@schinagl.nl>
> Signed-off-by: Wills Wang <wills.wang.open@gmail.com>
> Signed-off-by: Ian Campbell <ijc@hellion.org.uk>
> Cc: Pantelis Antoniou <panto@antoniou-consulting.com>
[...]

> +
> +static void dumphex32(char *name, char *base, int len)
> +{
> +	__u32 i;
> +
> +	debug("dump %s registers:", name);
> +	for (i = 0; i < len; i += 4) {
> +		if (!(i & 0xf))
> +			debug("\n0x%p : ", base + i);
> +		debug("0x%08x ", readl(base + i));
> +	}
> +	debug("\n");
> +}

Looks like print_hex_dump() reimplementation ...

[...]

> +static int mmc_trans_data_by_cpu(struct mmc *mmc, struct mmc_data *data)
> +{
> +	struct sunxi_mmc_host *mmchost = (struct sunxi_mmc_host *)mmc->priv;
> +	unsigned i;
> +	unsigned byte_cnt = data->blocksize * data->blocks;
> +	unsigned *buff;
> +	unsigned timeout = 0xfffff;
> +
> +	if (data->flags & MMC_DATA_READ) {
> +		buff = (unsigned int *)data->dest;
> +		for (i = 0; i < (byte_cnt >> 2); i++) {
> +			while (--timeout &&
> +			       (readl(&mmchost->reg->status) &
> +				SUNXI_MMC_STATUS_FIFO_EMPTY))
> +				;
> +			if (timeout <= 0)
> +				goto out;
> +			buff[i] = readl(mmchost->database);
> +			timeout = 0xfffff;
> +		}
> +	} else {
> +		buff = (unsigned int *)data->src;
> +		for (i = 0; i < (byte_cnt >> 2); i++) {
> +			while (--timeout &&
> +			       (readl(&mmchost->reg->status) &
> +				SUNXI_MMC_STATUS_FIFO_FULL))
> +				;
> +			if (timeout <= 0)
> +				goto out;
> +			writel(buff[i], mmchost->database);
> +			timeout = 0xfffff;

Are these two branches almost the same ? Why not just clear that up by squashing 
them into one with a small if (...) at the begining of this function ?

[...]

> +static int mmc_trans_data_by_dma(struct mmc *mmc, struct mmc_data *data)
> +{
> +	struct sunxi_mmc_host *mmchost = (struct sunxi_mmc_host *)mmc->priv;
> +	unsigned byte_cnt = data->blocksize * data->blocks;
> +	unsigned char *buff;
> +	unsigned des_idx = 0;
> +	unsigned buff_frag_num =
> +		(byte_cnt + SDXC_DES_BUFFER_MAX_LEN - 1) >> SDXC_DES_NUM_SHIFT;
> +	unsigned remain;
> +	unsigned i, rval;
> +	ALLOC_CACHE_ALIGN_BUFFER(struct sunxi_mmc_des, pdes, buff_frag_num);
> +
> +	buff = data->flags & MMC_DATA_READ ?
> +	    (unsigned char *)data->dest : (unsigned char *)data->src;
> +	remain = byte_cnt & (SDXC_DES_BUFFER_MAX_LEN - 1);
> +	if (!remain)
> +		remain = SDXC_DES_BUFFER_MAX_LEN;
> +
> +	flush_cache((unsigned long)buff, (unsigned long)byte_cnt);
> +	for (i = 0; i < buff_frag_num; i++, des_idx++) {
> +		memset((void *)&pdes[des_idx], 0, sizeof(struct sunxi_mmc_des));
> +		pdes[des_idx].des_chain = 1;
> +		pdes[des_idx].own = 1;
> +		pdes[des_idx].dic = 1;
> +		if (buff_frag_num > 1 && i != buff_frag_num - 1)
> +			pdes[des_idx].data_buf1_sz =
> +			    (SDXC_DES_BUFFER_MAX_LEN -
> +			     1) & SDXC_DES_BUFFER_MAX_LEN;
> +		else
> +			pdes[des_idx].data_buf1_sz = remain;
> +
> +		pdes[des_idx].buf_addr_ptr1 =
> +		    (u32) buff + i * SDXC_DES_BUFFER_MAX_LEN;
> +		if (i == 0)
> +			pdes[des_idx].first_des = 1;
> +
> +		if (i == buff_frag_num - 1) {
> +			pdes[des_idx].dic = 0;
> +			pdes[des_idx].last_des = 1;
> +			pdes[des_idx].end_of_ring = 1;
> +			pdes[des_idx].buf_addr_ptr2 = 0;
> +		} else {
> +			pdes[des_idx].buf_addr_ptr2 = (u32)&pdes[des_idx + 1];
> +		}
> +		debug("frag %d, remain %d, des[%d](%08x): ",
> +		      i, remain, des_idx, (u32)&pdes[des_idx]);
> +		debug("[0] = %08x, [1] = %08x, [2] = %08x, [3] = %08x\n",
> +		      (u32)((u32 *)&pdes[des_idx])[0],
> +		      (u32)((u32 *)&pdes[des_idx])[1],
> +		      (u32)((u32 *)&pdes[des_idx])[2],
> +		      (u32)((u32 *)&pdes[des_idx])[3]);

Yum, this pointer voodoo looks tasty (and ready for fixing up ... ).
[...]