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From:   Paul Cercueil <paul@crapouillou.net>
To:     David Woodhouse <dwmw2@infradead.org>,
        Brian Norris <computersforpeace@gmail.com>,
        Boris Brezillon <bbrezillon@kernel.org>,
        Marek Vasut <marek.vasut@gmail.com>,
        Richard Weinberger <richard@nod.at>,
        Rob Herring <robh+dt@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Miquel Raynal <miquel.raynal@bootlin.com>,
        Harvey Hunt <harveyhuntnexus@gmail.com>
Cc:     Mathieu Malaterre <malat@debian.org>,
        linux-mtd@lists.infradead.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, Paul Cercueil <paul@crapouillou.net>
Subject: [PATCH v2 4/9] mtd: rawnand: jz4780: Add support for the JZ4740
Date:   Sat,  2 Feb 2019 20:19:21 -0300
Message-Id: <20190202231926.2444-5-paul@crapouillou.net>
In-Reply-To: <20190202231926.2444-1-paul@crapouillou.net>
References: <20190202231926.2444-1-paul@crapouillou.net>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Add support for probing the jz4780-nand driver on the JZ4740 SoC from
Ingenic.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
---

Changes:

v2: - Add support for the JZ4740 and not the JZ4725B: they behave the
      same, and JZ4740 is fully upstream while JZ4725B is not. The
      JZ4725B devicetree will then simply use the "ingenic,jz4740-nand"
      compatible string.
    - Fix the number of bytes for the ECC when the ECC strength is 4.
      This is needed for the JZ4740, which uses Reed-Solomon instead of
      BCH.

 drivers/mtd/nand/raw/ingenic/jz4780_nand.c | 48 +++++++++++++++++-----
 1 file changed, 37 insertions(+), 11 deletions(-)

diff --git a/drivers/mtd/nand/raw/ingenic/jz4780_nand.c b/drivers/mtd/nand/raw/ingenic/jz4780_nand.c
index 7f55358b860f..c0855fef7735 100644
--- a/drivers/mtd/nand/raw/ingenic/jz4780_nand.c
+++ b/drivers/mtd/nand/raw/ingenic/jz4780_nand.c
@@ -13,6 +13,7 @@
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
+#include <linux/of_device.h>
 #include <linux/gpio/consumer.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
@@ -26,13 +27,15 @@
 
 #define DRV_NAME	"jz4780-nand"
 
-#define OFFSET_DATA	0x00000000
-#define OFFSET_CMD	0x00400000
-#define OFFSET_ADDR	0x00800000
-
 /* Command delay when there is no R/B pin. */
 #define RB_DELAY_US	100
 
+struct jz_soc_info {
+	unsigned long data_offset;
+	unsigned long addr_offset;
+	unsigned long cmd_offset;
+};
+
 struct jz4780_nand_cs {
 	unsigned int bank;
 	void __iomem *base;
@@ -40,6 +43,7 @@ struct jz4780_nand_cs {
 
 struct jz4780_nand_controller {
 	struct device *dev;
+	const struct jz_soc_info *soc_info;
 	struct jz4780_bch *bch;
 	struct nand_controller controller;
 	unsigned int num_banks;
@@ -101,9 +105,9 @@ static void jz4780_nand_cmd_ctrl(struct nand_chip *chip, int cmd,
 		return;
 
 	if (ctrl & NAND_ALE)
-		writeb(cmd, cs->base + OFFSET_ADDR);
+		writeb(cmd, cs->base + nfc->soc_info->addr_offset);
 	else if (ctrl & NAND_CLE)
-		writeb(cmd, cs->base + OFFSET_CMD);
+		writeb(cmd, cs->base + nfc->soc_info->cmd_offset);
 }
 
 static int jz4780_nand_dev_ready(struct nand_chip *chip)
@@ -161,8 +165,13 @@ static int jz4780_nand_attach_chip(struct nand_chip *chip)
 	struct jz4780_nand_controller *nfc = to_jz4780_nand_controller(chip->controller);
 	int eccbytes;
 
-	chip->ecc.bytes = fls((1 + 8) * chip->ecc.size)	*
-				(chip->ecc.strength / 8);
+	if (chip->ecc.strength == 4) {
+		/* JZ4740 uses 9 bytes of ECC to correct maximum 4 errors */
+		chip->ecc.bytes = 9;
+	} else {
+		chip->ecc.bytes = fls((1 + 8) * chip->ecc.size)	*
+				  (chip->ecc.strength / 8);
+	}
 
 	switch (chip->ecc.mode) {
 	case NAND_ECC_HW:
@@ -272,8 +281,8 @@ static int jz4780_nand_init_chip(struct platform_device *pdev,
 		return -ENOMEM;
 	mtd->dev.parent = dev;
 
-	chip->legacy.IO_ADDR_R = cs->base + OFFSET_DATA;
-	chip->legacy.IO_ADDR_W = cs->base + OFFSET_DATA;
+	chip->legacy.IO_ADDR_R = cs->base + nfc->soc_info->data_offset;
+	chip->legacy.IO_ADDR_W = cs->base + nfc->soc_info->data_offset;
 	chip->legacy.chip_delay = RB_DELAY_US;
 	chip->options = NAND_NO_SUBPAGE_WRITE;
 	chip->legacy.select_chip = jz4780_nand_select_chip;
@@ -353,6 +362,10 @@ static int jz4780_nand_probe(struct platform_device *pdev)
 	if (!nfc)
 		return -ENOMEM;
 
+	nfc->soc_info = device_get_match_data(dev);
+	if (!nfc->soc_info)
+		return -EINVAL;
+
 	/*
 	 * Check for BCH HW before we call nand_scan_ident, to prevent us from
 	 * having to call it again if the BCH driver returns -EPROBE_DEFER.
@@ -390,8 +403,21 @@ static int jz4780_nand_remove(struct platform_device *pdev)
 	return 0;
 }
 
+static const struct jz_soc_info jz4740_soc_info = {
+	.data_offset = 0x00000000,
+	.cmd_offset  = 0x00008000,
+	.addr_offset = 0x00010000,
+};
+
+static const struct jz_soc_info jz4780_soc_info = {
+	.data_offset = 0x00000000,
+	.cmd_offset  = 0x00400000,
+	.addr_offset = 0x00800000,
+};
+
 static const struct of_device_id jz4780_nand_dt_match[] = {
-	{ .compatible = "ingenic,jz4780-nand" },
+	{ .compatible = "ingenic,jz4740-nand", .data = &jz4740_soc_info },
+	{ .compatible = "ingenic,jz4780-nand",  .data = &jz4780_soc_info  },
 	{},
 };
 MODULE_DEVICE_TABLE(of, jz4780_nand_dt_match);
-- 
2.20.1