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>

1 files changed, 68 insertions, 0 deletions

diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
index 877ce1757d..ab2483e9db 100644
--- a/drivers/mmc/mmc.c
+++ b/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)
 {