[PATCH v2 05/15] mtd: rawnand: sunxi: rework pattern found registers

[Richard Genoud <richard.genoud@bootlin.com>]

On H6/H616, the register ECC_PAT_FOUND is at its own address, and not
part of ECC status register.
So, introduce the pattern found register offset in sunxi_nfc_caps, along
with its mask.

Also, introduce a non compile-time field_get() because FIELD_GET() and
u32_get_bits() don't work with non compile-time constant.
https://lore.kernel.org/lkml/cover.1739540679.git.geert+renesas@glider.be/

No functional change.

Signed-off-by: Richard Genoud <richard.genoud@bootlin.com>
---
 drivers/mtd/nand/raw/sunxi_nand.c | 36 ++++++++++++++++++++++++++-----
 1 file changed, 31 insertions(+), 5 deletions(-)

diff --git a/drivers/mtd/nand/raw/sunxi_nand.c b/drivers/mtd/nand/raw/sunxi_nand.c
index 8f5d8df19e33..4cfb5d3e9c06 100644
--- a/drivers/mtd/nand/raw/sunxi_nand.c
+++ b/drivers/mtd/nand/raw/sunxi_nand.c
@@ -29,6 +29,9 @@
 #include <linux/iopoll.h>
 #include <linux/reset.h>
 
+/* non compile-time field get */
+#define field_get(_mask, _reg) (((_reg) & (_mask)) >> (ffs(_mask) - 1))
+
 #define NFC_REG_CTL		0x0000
 #define NFC_REG_ST		0x0004
 #define NFC_REG_INT		0x0008
@@ -150,7 +153,13 @@
 /* define bit use in NFC_ECC_ST */
 #define NFC_ECC_ERR(x)		BIT(x)
 #define NFC_ECC_ERR_MSK		GENMASK(15, 0)
-#define NFC_ECC_PAT_FOUND(x)	BIT(x + 16)
+
+/*
+ * define bit use in NFC_REG_PAT_FOUND
+ * For A10/A23, NFC_REG_PAT_FOUND == NFC_ECC_ST register
+ */
+#define NFC_ECC_PAT_FOUND_MSK(nfc) (nfc->caps->pat_found_mask)
+
 #define NFC_ECC_ERR_CNT(b, x)	(((x) >> (((b) % 4) * 8)) & 0xff)
 
 #define NFC_DEFAULT_TIMEOUT_MS	1000
@@ -216,6 +225,8 @@ static inline struct sunxi_nand_chip *to_sunxi_nand(struct nand_chip *nand)
  * @reg_io_data:	I/O data register
  * @reg_ecc_err_cnt:	ECC error counter register
  * @reg_user_data:	User data register
+ * @reg_pat_found:	Data Pattern Status Register
+ * @pat_found_mask:	ECC_PAT_FOUND mask in NFC_REG_PAT_FOUND register
  * @dma_maxburst:	DMA maxburst
  * @ecc_strengths:	Available ECC strengths array
  * @nstrengths:		Size of @ecc_strengths
@@ -225,6 +236,8 @@ struct sunxi_nfc_caps {
 	unsigned int reg_io_data;
 	unsigned int reg_ecc_err_cnt;
 	unsigned int reg_user_data;
+	unsigned int reg_pat_found;
+	unsigned int pat_found_mask;
 	unsigned int dma_maxburst;
 	const u8 *ecc_strengths;
 	unsigned int nstrengths;
@@ -766,7 +779,8 @@ static void sunxi_nfc_hw_ecc_update_stats(struct nand_chip *nand,
 }
 
 static int sunxi_nfc_hw_ecc_correct(struct nand_chip *nand, u8 *data, u8 *oob,
-				    int step, u32 status, bool *erased)
+				    int step, u32 status, u32 pattern_found,
+				    bool *erased)
 {
 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
 	struct nand_ecc_ctrl *ecc = &nand->ecc;
@@ -777,7 +791,7 @@ static int sunxi_nfc_hw_ecc_correct(struct nand_chip *nand, u8 *data, u8 *oob,
 	if (status & NFC_ECC_ERR(step))
 		return -EBADMSG;
 
-	if (status & NFC_ECC_PAT_FOUND(step)) {
+	if (pattern_found & BIT(step)) {
 		u8 pattern;
 
 		if (unlikely(!(readl(nfc->regs + NFC_REG_PAT_ID) & 0x1))) {
@@ -811,6 +825,7 @@ static int sunxi_nfc_hw_ecc_read_chunk(struct nand_chip *nand,
 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
 	struct nand_ecc_ctrl *ecc = &nand->ecc;
 	int raw_mode = 0;
+	u32 pattern_found;
 	bool erased;
 	int ret;
 
@@ -838,8 +853,12 @@ static int sunxi_nfc_hw_ecc_read_chunk(struct nand_chip *nand,
 
 	*cur_off = oob_off + ecc->bytes + 4;
 
+	pattern_found = readl(nfc->regs + nfc->caps->reg_pat_found);
+	pattern_found = field_get(NFC_ECC_PAT_FOUND_MSK(nfc), pattern_found);
+
 	ret = sunxi_nfc_hw_ecc_correct(nand, data, oob_required ? oob : NULL, 0,
 				       readl(nfc->regs + NFC_REG_ECC_ST),
+				       pattern_found,
 				       &erased);
 	if (erased)
 		return 1;
@@ -920,7 +939,7 @@ static int sunxi_nfc_hw_ecc_read_chunks_dma(struct nand_chip *nand, uint8_t *buf
 	unsigned int max_bitflips = 0;
 	int ret, i, raw_mode = 0;
 	struct scatterlist sg;
-	u32 status, wait;
+	u32 status, pattern_found, wait;
 
 	ret = sunxi_nfc_wait_cmd_fifo_empty(nfc);
 	if (ret)
@@ -961,6 +980,8 @@ static int sunxi_nfc_hw_ecc_read_chunks_dma(struct nand_chip *nand, uint8_t *buf
 		return ret;
 
 	status = readl(nfc->regs + NFC_REG_ECC_ST);
+	pattern_found = readl(nfc->regs + nfc->caps->reg_pat_found);
+	pattern_found = field_get(NFC_ECC_PAT_FOUND_MSK(nfc), pattern_found);
 
 	for (i = 0; i < nchunks; i++) {
 		int data_off = i * ecc->size;
@@ -971,7 +992,8 @@ static int sunxi_nfc_hw_ecc_read_chunks_dma(struct nand_chip *nand, uint8_t *buf
 
 		ret = sunxi_nfc_hw_ecc_correct(nand, randomized ? data : NULL,
 					       oob_required ? oob : NULL,
-					       i, status, &erased);
+					       i, status, pattern_found,
+					       &erased);
 
 		/* ECC errors are handled in the second loop. */
 		if (ret < 0)
@@ -2185,6 +2207,8 @@ static const struct sunxi_nfc_caps sunxi_nfc_a10_caps = {
 	.reg_io_data = NFC_REG_A10_IO_DATA,
 	.reg_ecc_err_cnt = NFC_REG_A10_ECC_ERR_CNT,
 	.reg_user_data = NFC_REG_A10_USER_DATA,
+	.reg_pat_found = NFC_REG_ECC_ST,
+	.pat_found_mask = GENMASK(31, 16),
 	.dma_maxburst = 4,
 	.ecc_strengths = sunxi_ecc_strengths_a10,
 	.nstrengths = ARRAY_SIZE(sunxi_ecc_strengths_a10),
@@ -2195,6 +2219,8 @@ static const struct sunxi_nfc_caps sunxi_nfc_a23_caps = {
 	.reg_io_data = NFC_REG_A23_IO_DATA,
 	.reg_ecc_err_cnt = NFC_REG_A10_ECC_ERR_CNT,
 	.reg_user_data = NFC_REG_A10_USER_DATA,
+	.reg_pat_found = NFC_REG_ECC_ST,
+	.pat_found_mask = GENMASK(31, 16),
 	.dma_maxburst = 8,
 	.ecc_strengths = sunxi_ecc_strengths_a10,
 	.nstrengths = ARRAY_SIZE(sunxi_ecc_strengths_a10),