mtd: rawnand: marvell: add support for AC5 SoC

Add support for the AC5/AC5X SoC from Marvell. The NFC on this SoC only
supports SDR modes up to 3.

Marvell's SDK includes some predefined values for the ndtr registers.
These haven't been incorporated as the existing code seems to get good
values based on measurements taken with an oscilloscope.
Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20230703035044.2063303-4-chris.packham@alliedtelesis.co.nz

drivers/mtd/nand/raw/Kconfig

@@ -160,7 +160,7 @@ config MTD_NAND_MARVELL
 	  including:
 	  - PXA3xx processors (NFCv1)
 	  - 32-bit Armada platforms (XP, 37x, 38x, 39x) (NFCv2)
-	  - 64-bit Aramda platforms (7k, 8k) (NFCv2)
+	  - 64-bit Aramda platforms (7k, 8k, ac5) (NFCv2)
 
 config MTD_NAND_SLC_LPC32XX
 	tristate "NXP LPC32xx SLC NAND controller"

drivers/mtd/nand/raw/marvell_nand.c

@@ -375,6 +375,7 @@ static inline struct marvell_nand_chip_sel *to_nand_sel(struct marvell_nand_chip
  *			BCH error detection and correction algorithm,
  *			NDCB3 register has been added
  * @use_dma:		Use dma for data transfers
+ * @max_mode_number:	Maximum timing mode supported by the controller
  */
 struct marvell_nfc_caps {
 	unsigned int max_cs_nb;
@@ -383,6 +384,7 @@ struct marvell_nfc_caps {
 	bool legacy_of_bindings;
 	bool is_nfcv2;
 	bool use_dma;
+	unsigned int max_mode_number;
 };
 
 /**
@@ -2376,6 +2378,9 @@ static int marvell_nfc_setup_interface(struct nand_chip *chip, int chipnr,
 	if (IS_ERR(sdr))
 		return PTR_ERR(sdr);
 
+	if (nfc->caps->max_mode_number && nfc->caps->max_mode_number < conf->timings.mode)
+		return -EOPNOTSUPP;
+
 	/*
 	 * SDR timings are given in pico-seconds while NFC timings must be
 	 * expressed in NAND controller clock cycles, which is half of the
@@ -3073,6 +3078,13 @@ static const struct marvell_nfc_caps marvell_armada_8k_nfc_caps = {
 	.is_nfcv2 = true,
 };
 
+static const struct marvell_nfc_caps marvell_ac5_caps = {
+	.max_cs_nb = 2,
+	.max_rb_nb = 1,
+	.is_nfcv2 = true,
+	.max_mode_number = 3,
+};
+
 static const struct marvell_nfc_caps marvell_armada370_nfc_caps = {
 	.max_cs_nb = 4,
 	.max_rb_nb = 2,
@@ -3121,6 +3133,10 @@ static const struct of_device_id marvell_nfc_of_ids[] = {
 		.compatible = "marvell,armada-8k-nand-controller",
 		.data = &marvell_armada_8k_nfc_caps,
 	},
+	{
+		.compatible = "marvell,ac5-nand-controller",
+		.data = &marvell_ac5_caps,
+	},
 	{
 		.compatible = "marvell,armada370-nand-controller",
 		.data = &marvell_armada370_nfc_caps,