mtd: rawnand: Macronix: Add support for block protection

Macronix AC/AD series support using SET_FEATURES to change block
protection and unprotection. Block protection support can be checked
with GET_FEATURES.
Signed-off-by: Mason Yang <masonccyang@mxic.com.tw>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/1583220084-10890-3-git-send-email-masonccyang@mxic.com.tw

drivers/mtd/nand/raw/nand_macronix.c

@@ -11,6 +11,10 @@
 #define MACRONIX_READ_RETRY_BIT BIT(0)
 #define MACRONIX_NUM_READ_RETRY_MODES 6
 
+#define ONFI_FEATURE_ADDR_MXIC_PROTECTION 0xA0
+#define MXIC_BLOCK_PROTECTION_ALL_LOCK 0x38
+#define MXIC_BLOCK_PROTECTION_ALL_UNLOCK 0x0
+
 #define ONFI_FEATURE_ADDR_MXIC_RANDOMIZER 0xB0
 #define MACRONIX_RANDOMIZER_BIT BIT(1)
 #define MACRONIX_RANDOMIZER_ENPGM BIT(0)
@@ -172,6 +176,73 @@ static void macronix_nand_fix_broken_get_timings(struct nand_chip *chip)
 		     ONFI_FEATURE_ADDR_TIMING_MODE, 1);
 }
 
+/*
+ * Macronix NAND supports Block Protection by Protectoin(PT) pin;
+ * active high at power-on which protects the entire chip even the #WP is
+ * disabled. Lock/unlock protection area can be partition according to
+ * protection bits, i.e. upper 1/2 locked, upper 1/4 locked and so on.
+ */
+static int mxic_nand_lock(struct nand_chip *chip, loff_t ofs, uint64_t len)
+{
+	u8 feature[ONFI_SUBFEATURE_PARAM_LEN];
+	int ret;
+
+	feature[0] = MXIC_BLOCK_PROTECTION_ALL_LOCK;
+	nand_select_target(chip, 0);
+	ret = nand_set_features(chip, ONFI_FEATURE_ADDR_MXIC_PROTECTION,
+				feature);
+	nand_deselect_target(chip);
+	if (ret)
+		pr_err("%s all blocks failed\n", __func__);
+
+	return ret;
+}
+
+static int mxic_nand_unlock(struct nand_chip *chip, loff_t ofs, uint64_t len)
+{
+	u8 feature[ONFI_SUBFEATURE_PARAM_LEN];
+	int ret;
+
+	feature[0] = MXIC_BLOCK_PROTECTION_ALL_UNLOCK;
+	nand_select_target(chip, 0);
+	ret = nand_set_features(chip, ONFI_FEATURE_ADDR_MXIC_PROTECTION,
+				feature);
+	nand_deselect_target(chip);
+	if (ret)
+		pr_err("%s all blocks failed\n", __func__);
+
+	return ret;
+}
+
+static void macronix_nand_block_protection_support(struct nand_chip *chip)
+{
+	u8 feature[ONFI_SUBFEATURE_PARAM_LEN];
+	int ret;
+
+	bitmap_set(chip->parameters.get_feature_list,
+		   ONFI_FEATURE_ADDR_MXIC_PROTECTION, 1);
+
+	feature[0] = MXIC_BLOCK_PROTECTION_ALL_UNLOCK;
+	nand_select_target(chip, 0);
+	ret = nand_get_features(chip, ONFI_FEATURE_ADDR_MXIC_PROTECTION,
+				feature);
+	nand_deselect_target(chip);
+	if (ret || feature[0] != MXIC_BLOCK_PROTECTION_ALL_LOCK) {
+		if (ret)
+			pr_err("Block protection check failed\n");
+
+		bitmap_clear(chip->parameters.get_feature_list,
+			     ONFI_FEATURE_ADDR_MXIC_PROTECTION, 1);
+		return;
+	}
+
+	bitmap_set(chip->parameters.set_feature_list,
+		   ONFI_FEATURE_ADDR_MXIC_PROTECTION, 1);
+
+	chip->lock_area = mxic_nand_lock;
+	chip->unlock_area = mxic_nand_unlock;
+}
+
 static int macronix_nand_init(struct nand_chip *chip)
 {
 	if (nand_is_slc(chip))
@@ -179,6 +250,7 @@ static int macronix_nand_init(struct nand_chip *chip)
 
 	macronix_nand_fix_broken_get_timings(chip);
 	macronix_nand_onfi_init(chip);
+	macronix_nand_block_protection_support(chip);
 
 	return 0;
 }