mmc: add a library function to send tuning command

HS200/SDR104 requires tuning command to be sent to the card.
Add a simple function to send tuning command and to read and
compare the received data with the tuning block pattern.
This function can be used by platform driver to perform DLL
tuning.
This patch is similar to
commit 996903de92f0 ("mmc: core: add core-level function for
sending tuning commands") added in linux kernel.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Jean-Jacques Hiblot <jjhiblot@ti.com>

drivers/mmc/mmc.c

@@ -308,6 +308,74 @@ int mmc_set_blocklen(struct mmc *mmc, int len)
 	return err;
 }
 
+static const u8 tuning_blk_pattern_4bit[] = {
+	0xff, 0x0f, 0xff, 0x00, 0xff, 0xcc, 0xc3, 0xcc,
+	0xc3, 0x3c, 0xcc, 0xff, 0xfe, 0xff, 0xfe, 0xef,
+	0xff, 0xdf, 0xff, 0xdd, 0xff, 0xfb, 0xff, 0xfb,
+	0xbf, 0xff, 0x7f, 0xff, 0x77, 0xf7, 0xbd, 0xef,
+	0xff, 0xf0, 0xff, 0xf0, 0x0f, 0xfc, 0xcc, 0x3c,
+	0xcc, 0x33, 0xcc, 0xcf, 0xff, 0xef, 0xff, 0xee,
+	0xff, 0xfd, 0xff, 0xfd, 0xdf, 0xff, 0xbf, 0xff,
+	0xbb, 0xff, 0xf7, 0xff, 0xf7, 0x7f, 0x7b, 0xde,
+};
+
+static const u8 tuning_blk_pattern_8bit[] = {
+	0xff, 0xff, 0x00, 0xff, 0xff, 0xff, 0x00, 0x00,
+	0xff, 0xff, 0xcc, 0xcc, 0xcc, 0x33, 0xcc, 0xcc,
+	0xcc, 0x33, 0x33, 0xcc, 0xcc, 0xcc, 0xff, 0xff,
+	0xff, 0xee, 0xff, 0xff, 0xff, 0xee, 0xee, 0xff,
+	0xff, 0xff, 0xdd, 0xff, 0xff, 0xff, 0xdd, 0xdd,
+	0xff, 0xff, 0xff, 0xbb, 0xff, 0xff, 0xff, 0xbb,
+	0xbb, 0xff, 0xff, 0xff, 0x77, 0xff, 0xff, 0xff,
+	0x77, 0x77, 0xff, 0x77, 0xbb, 0xdd, 0xee, 0xff,
+	0xff, 0xff, 0xff, 0x00, 0xff, 0xff, 0xff, 0x00,
+	0x00, 0xff, 0xff, 0xcc, 0xcc, 0xcc, 0x33, 0xcc,
+	0xcc, 0xcc, 0x33, 0x33, 0xcc, 0xcc, 0xcc, 0xff,
+	0xff, 0xff, 0xee, 0xff, 0xff, 0xff, 0xee, 0xee,
+	0xff, 0xff, 0xff, 0xdd, 0xff, 0xff, 0xff, 0xdd,
+	0xdd, 0xff, 0xff, 0xff, 0xbb, 0xff, 0xff, 0xff,
+	0xbb, 0xbb, 0xff, 0xff, 0xff, 0x77, 0xff, 0xff,
+	0xff, 0x77, 0x77, 0xff, 0x77, 0xbb, 0xdd, 0xee,
+};
+
+int mmc_send_tuning(struct mmc *mmc, u32 opcode, int *cmd_error)
+{
+	struct mmc_cmd cmd;
+	struct mmc_data data;
+	const u8 *tuning_block_pattern;
+	int size, err;
+
+	if (mmc->bus_width == 8) {
+		tuning_block_pattern = tuning_blk_pattern_8bit;
+		size = sizeof(tuning_blk_pattern_8bit);
+	} else if (mmc->bus_width == 4) {
+		tuning_block_pattern = tuning_blk_pattern_4bit;
+		size = sizeof(tuning_blk_pattern_4bit);
+	} else {
+		return -EINVAL;
+	}
+
+	ALLOC_CACHE_ALIGN_BUFFER(u8, data_buf, size);
+
+	cmd.cmdidx = opcode;
+	cmd.cmdarg = 0;
+	cmd.resp_type = MMC_RSP_R1;
+
+	data.dest = (void *)data_buf;
+	data.blocks = 1;
+	data.blocksize = size;
+	data.flags = MMC_DATA_READ;
+
+	err = mmc_send_cmd(mmc, &cmd, &data);
+	if (err)
+		return err;
+
+	if (memcmp(data_buf, tuning_block_pattern, size))
+		return -EIO;
+
+	return 0;
+}
+
 static int mmc_read_blocks(struct mmc *mmc, void *dst, lbaint_t start,
 			   lbaint_t blkcnt)
 {

include/mmc.h

@@ -650,6 +650,7 @@ void mmc_destroy(struct mmc *mmc);
 int mmc_unbind(struct udevice *dev);
 int mmc_initialize(bd_t *bis);
 int mmc_init(struct mmc *mmc);
+int mmc_send_tuning(struct mmc *mmc, u32 opcode, int *cmd_error);
 int mmc_read(struct mmc *mmc, u64 src, uchar *dst, int size);
 
 /**