[PATCH 7/7] mtd: rawnand: sunxi: Precompute the ECC_CTL register value

[Samuel Holland]

This removes an unnecessary memory allocation, and avoids recomputing
the same register value every time ECC is enabled.

Signed-off-by: Samuel Holland <samuel at sholland.org>
---

 drivers/mtd/nand/raw/sunxi_nand.c | 75 ++++++-------------------------
 1 file changed, 13 insertions(+), 62 deletions(-)

diff --git a/drivers/mtd/nand/raw/sunxi_nand.c b/drivers/mtd/nand/raw/sunxi_nand.c
index a3bc9f7f9e5a..5c5a567d8870 100644
--- a/drivers/mtd/nand/raw/sunxi_nand.c
+++ b/drivers/mtd/nand/raw/sunxi_nand.c
@@ -169,22 +169,13 @@ struct sunxi_nand_chip_sel {
 	s8 rb;
 };
 
-/**
- * struct sunxi_nand_hw_ecc - stores information related to HW ECC support
- *
- * @mode: the sunxi ECC mode field deduced from ECC requirements
- */
-struct sunxi_nand_hw_ecc {
-	int mode;
-};
-
 /**
  * struct sunxi_nand_chip - stores NAND chip device related information
  *
  * @node: used to store NAND chips into a list
  * @nand: base NAND chip structure
- * @ecc: ECC controller structure
  * @clk_rate: clk_rate required for this NAND chip
+ * @ecc_ctl: ECC_CTL register value for this NAND chip
  * @timing_cfg: TIMING_CFG register value for this NAND chip
  * @timing_ctl: TIMING_CTL register value for this NAND chip
  * @nsels: number of CS lines required by the NAND chip
@@ -193,8 +184,8 @@ struct sunxi_nand_hw_ecc {
 struct sunxi_nand_chip {
 	struct list_head node;
 	struct nand_chip nand;
-	struct sunxi_nand_hw_ecc *ecc;
 	unsigned long clk_rate;
+	u32 ecc_ctl;
 	u32 timing_cfg;
 	u32 timing_ctl;
 	int nsels;
@@ -689,26 +680,15 @@ static void sunxi_nfc_hw_ecc_enable(struct nand_chip *nand)
 {
 	struct sunxi_nand_chip *sunxi_nand = to_sunxi_nand(nand);
 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
-	u32 ecc_ctl;
-
-	ecc_ctl = readl(nfc->regs + NFC_REG_ECC_CTL);
-	ecc_ctl &= ~(NFC_ECC_MODE_MSK | NFC_ECC_PIPELINE |
-		     NFC_ECC_BLOCK_SIZE_MSK);
-	ecc_ctl |= NFC_ECC_EN | NFC_ECC_MODE(sunxi_nand->ecc->mode) |
-		   NFC_ECC_EXCEPTION | NFC_ECC_PIPELINE;
-
-	if (nand->ecc.size == 512)
-		ecc_ctl |= NFC_ECC_BLOCK_512;
 
-	writel(ecc_ctl, nfc->regs + NFC_REG_ECC_CTL);
+	writel(sunxi_nand->ecc_ctl, nfc->regs + NFC_REG_ECC_CTL);
 }
 
 static void sunxi_nfc_hw_ecc_disable(struct nand_chip *nand)
 {
 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
 
-	writel(readl(nfc->regs + NFC_REG_ECC_CTL) & ~NFC_ECC_EN,
-	       nfc->regs + NFC_REG_ECC_CTL);
+	writel(0, nfc->regs + NFC_REG_ECC_CTL);
 }
 
 static inline void sunxi_nfc_user_data_to_buf(u32 user_data, u8 *buf)
@@ -1626,11 +1606,6 @@ static const struct mtd_ooblayout_ops sunxi_nand_ooblayout_ops = {
 	.free = sunxi_nand_ooblayout_free,
 };
 
-static void sunxi_nand_hw_ecc_ctrl_cleanup(struct sunxi_nand_chip *sunxi_nand)
-{
-	kfree(sunxi_nand->ecc);
-}
-
 static int sunxi_nand_hw_ecc_ctrl_init(struct nand_chip *nand,
 				       struct nand_ecc_ctrl *ecc,
 				       struct device_node *np)
@@ -1641,7 +1616,6 @@ static int sunxi_nand_hw_ecc_ctrl_init(struct nand_chip *nand,
 	struct mtd_info *mtd = nand_to_mtd(nand);
 	struct nand_device *nanddev = mtd_to_nanddev(mtd);
 	int nsectors;
-	int ret;
 	int i;
 
 	if (nanddev->ecc.user_conf.flags & NAND_ECC_MAXIMIZE_STRENGTH) {
@@ -1675,10 +1649,6 @@ static int sunxi_nand_hw_ecc_ctrl_init(struct nand_chip *nand,
 	if (ecc->size != 512 && ecc->size != 1024)
 		return -EINVAL;
 
-	sunxi_nand->ecc = kzalloc(sizeof(*sunxi_nand->ecc), GFP_KERNEL);
-	if (!sunxi_nand->ecc)
-		return -ENOMEM;
-
 	/* Prefer 1k ECC chunk over 512 ones */
 	if (ecc->size == 512 && mtd->writesize > 512) {
 		ecc->size = 1024;
@@ -1699,12 +1669,9 @@ static int sunxi_nand_hw_ecc_ctrl_init(struct nand_chip *nand,
 
 	if (i >= ARRAY_SIZE(strengths)) {
 		dev_err(nfc->dev, "unsupported strength\n");
-		ret = -ENOTSUPP;
-		goto err;
+		return -ENOTSUPP;
 	}
 
-	sunxi_nand->ecc->mode = i;
-
 	/* HW ECC always request ECC bytes for 1024 bytes blocks */
 	ecc->bytes = DIV_ROUND_UP(ecc->strength * fls(8 * 1024), 8);
 
@@ -1713,10 +1680,14 @@ static int sunxi_nand_hw_ecc_ctrl_init(struct nand_chip *nand,
 
 	nsectors = mtd->writesize / ecc->size;
 
-	if (mtd->oobsize < ((ecc->bytes + 4) * nsectors)) {
-		ret = -EINVAL;
-		goto err;
-	}
+	if (mtd->oobsize < ((ecc->bytes + 4) * nsectors))
+		return -EINVAL;
+
+	sunxi_nand->ecc_ctl = NFC_ECC_MODE(i) | NFC_ECC_EXCEPTION |
+			      NFC_ECC_PIPELINE | NFC_ECC_EN;
+
+	if (ecc->size == 512)
+		sunxi_nand->ecc_ctl |= NFC_ECC_BLOCK_512;
 
 	ecc->read_oob = sunxi_nfc_hw_ecc_read_oob;
 	ecc->write_oob = sunxi_nfc_hw_ecc_write_oob;
@@ -1739,25 +1710,6 @@ static int sunxi_nand_hw_ecc_ctrl_init(struct nand_chip *nand,
 	ecc->write_oob_raw = nand_write_oob_std;
 
 	return 0;
-
-err:
-	kfree(sunxi_nand->ecc);
-
-	return ret;
-}
-
-static void sunxi_nand_ecc_cleanup(struct sunxi_nand_chip *sunxi_nand)
-{
-	struct nand_ecc_ctrl *ecc = &sunxi_nand->nand.ecc;
-
-	switch (ecc->engine_type) {
-	case NAND_ECC_ENGINE_TYPE_ON_HOST:
-		sunxi_nand_hw_ecc_ctrl_cleanup(sunxi_nand);
-		break;
-	case NAND_ECC_ENGINE_TYPE_NONE:
-	default:
-		break;
-	}
 }
 
 static int sunxi_nand_attach_chip(struct nand_chip *nand)
@@ -1970,7 +1922,6 @@ static void sunxi_nand_chips_cleanup(struct sunxi_nfc *nfc)
 		ret = mtd_device_unregister(nand_to_mtd(chip));
 		WARN_ON(ret);
 		nand_cleanup(chip);
-		sunxi_nand_ecc_cleanup(sunxi_nand);
 		list_del(&sunxi_nand->node);
 	}
 }
-- 
2.37.4