[PATCH 3/9] mci: core: add product name extraction function

[Stefan Kerkmann <s.kerkmann@pengutronix.de>]

The product name field PNM is available for both SD cards (len=5) and
MMC cards (len=6). The currently used method doesn't respect the length
for MMC cards.

Signed-off-by: Stefan Kerkmann <s.kerkmann@pengutronix.de>
---
 drivers/mci/mci-core.c | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/drivers/mci/mci-core.c b/drivers/mci/mci-core.c
index 2a71fdd39a..df72445edd 100644
--- a/drivers/mci/mci-core.c
+++ b/drivers/mci/mci-core.c
@@ -1939,6 +1939,31 @@ static unsigned extract_oid(struct mci *mci)
 	return (mci->cid[0] >> 8) & 0xffff;
 }
 
+/**
+ * Extract the product name from the CID
+ * @param mci Instance data
+ *
+ * The 'PNM' is encoded in bit 103:64 in the CID for SD cards and 103:56 for
+ * MMC cards
+ */
+static void extract_pnm(struct mci *mci, char pnm[static 7])
+{
+	pnm[0] = UNSTUFF_BITS(mci->cid, 96, 8);
+	pnm[1] = UNSTUFF_BITS(mci->cid, 88, 8);
+	pnm[2] = UNSTUFF_BITS(mci->cid, 80, 8);
+	pnm[3] = UNSTUFF_BITS(mci->cid, 72, 8);
+	pnm[4] = UNSTUFF_BITS(mci->cid, 64, 8);
+
+	if (IS_SD(mci)) {
+		// SD cards have a 5 character long product name
+		pnm[5] = '\0';
+	} else {
+		// MMC cards have a 6 character long product name
+		pnm[5] = UNSTUFF_BITS(mci->cid, 56, 8);
+		pnm[6] = '\0';
+	}
+}
+
 /**
  * Extract the product revision from the CID
  * @param mci Instance data

-- 
2.39.2