mtd: rawnand: diskonchip: Implement exec_op()

Implement exec_op() so we can later get rid of the legacy
implementation.

It's worth noting that the new implementation assert/deassert the CE
pin on each operation, which might not be necessary. We also dropped
the extra reset done at chip selection time on DOC2001plus. If it's
needed we really should do something smarter, because having a reset
everytime we access the chip is not that great perf-wise.
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20200501143917.1388957-5-boris.brezillon@collabora.com

drivers/mtd/nand/raw/diskonchip.c

@@ -355,25 +355,38 @@ static void doc2000_readbuf(struct nand_chip *this, u_char *buf, int len)
 	}
 }
 
+/*
+ * We need our own readid() here because it's called before the NAND chip
+ * has been initialized, and calling nand_op_readid() would lead to a NULL
+ * pointer exception when dereferencing the NAND timings.
+ */
+static void doc200x_readid(struct nand_chip *this, unsigned int cs, u8 *id)
+{
+	u8 addr = 0;
+	struct nand_op_instr instrs[] = {
+		NAND_OP_CMD(NAND_CMD_READID, 0),
+		NAND_OP_ADDR(1, &addr, 50),
+		NAND_OP_8BIT_DATA_IN(2, id, 0),
+	};
+
+	struct nand_operation op = NAND_OPERATION(cs, instrs);
+
+	if (!id)
+		op.ninstrs--;
+
+	this->controller->ops->exec_op(this, &op, false);
+}
+
 static uint16_t __init doc200x_ident_chip(struct mtd_info *mtd, int nr)
 {
 	struct nand_chip *this = mtd_to_nand(mtd);
 	struct doc_priv *doc = nand_get_controller_data(this);
 	uint16_t ret;
+	u8 id[2];
 
-	doc200x_select_chip(this, nr);
-	doc200x_hwcontrol(this, NAND_CMD_READID,
-			  NAND_CTRL_CLE | NAND_CTRL_CHANGE);
-	doc200x_hwcontrol(this, 0, NAND_CTRL_ALE | NAND_CTRL_CHANGE);
-	doc200x_hwcontrol(this, NAND_CMD_NONE, NAND_NCE | NAND_CTRL_CHANGE);
-
-	/* We can't use dev_ready here, but at least we wait for the
-	 * command to complete
-	 */
-	udelay(50);
+	doc200x_readid(this, nr, id);
 
-	ret = this->legacy.read_byte(this) << 8;
-	ret |= this->legacy.read_byte(this);
+	ret = ((u16)id[0] << 8) | id[1];
 
 	if (doc->ChipID == DOC_ChipID_Doc2k && try_dword && !nr) {
 		/* First chip probe. See if we get same results by 32-bit access */
@@ -383,13 +396,7 @@ static uint16_t __init doc200x_ident_chip(struct mtd_info *mtd, int nr)
 		} ident;
 		void __iomem *docptr = doc->virtadr;
 
-		doc200x_hwcontrol(this, NAND_CMD_READID,
-				  NAND_CTRL_CLE | NAND_CTRL_CHANGE);
-		doc200x_hwcontrol(this, 0, NAND_CTRL_ALE | NAND_CTRL_CHANGE);
-		doc200x_hwcontrol(this, NAND_CMD_NONE,
-				  NAND_NCE | NAND_CTRL_CHANGE);
-
-		udelay(50);
+		doc200x_readid(this, nr, NULL);
 
 		ident.dword = readl(docptr + DoC_2k_CDSN_IO);
 		if (((ident.byte[0] << 8) | ident.byte[1]) == ret) {
@@ -630,6 +637,166 @@ static void doc200x_hwcontrol(struct nand_chip *this, int cmd,
 	}
 }
 
+static void doc200x_write_control(struct doc_priv *doc, u8 value)
+{
+	WriteDOC(value, doc->virtadr, CDSNControl);
+	/* 11.4.3 -- 4 NOPs after CSDNControl write */
+	DoC_Delay(doc, 4);
+}
+
+static void doc200x_exec_instr(struct nand_chip *this,
+			       const struct nand_op_instr *instr)
+{
+	struct doc_priv *doc = nand_get_controller_data(this);
+	unsigned int i;
+
+	switch (instr->type) {
+	case NAND_OP_CMD_INSTR:
+		doc200x_write_control(doc, CDSN_CTRL_CE | CDSN_CTRL_CLE);
+		doc2000_write_byte(this, instr->ctx.cmd.opcode);
+		break;
+
+	case NAND_OP_ADDR_INSTR:
+		doc200x_write_control(doc, CDSN_CTRL_CE | CDSN_CTRL_ALE);
+		for (i = 0; i < instr->ctx.addr.naddrs; i++) {
+			u8 addr = instr->ctx.addr.addrs[i];
+
+			if (DoC_is_2000(doc))
+				doc2000_write_byte(this, addr);
+			else
+				doc2001_write_byte(this, addr);
+		}
+		break;
+
+	case NAND_OP_DATA_IN_INSTR:
+		doc200x_write_control(doc, CDSN_CTRL_CE);
+		if (DoC_is_2000(doc))
+			doc2000_readbuf(this, instr->ctx.data.buf.in,
+					instr->ctx.data.len);
+		else
+			doc2001_readbuf(this, instr->ctx.data.buf.in,
+					instr->ctx.data.len);
+		break;
+
+	case NAND_OP_DATA_OUT_INSTR:
+		doc200x_write_control(doc, CDSN_CTRL_CE);
+		if (DoC_is_2000(doc))
+			doc2000_writebuf(this, instr->ctx.data.buf.out,
+					 instr->ctx.data.len);
+		else
+			doc2001_writebuf(this, instr->ctx.data.buf.out,
+					 instr->ctx.data.len);
+		break;
+
+	case NAND_OP_WAITRDY_INSTR:
+		DoC_WaitReady(doc);
+		break;
+	}
+
+	if (instr->delay_ns)
+		ndelay(instr->delay_ns);
+}
+
+static int doc200x_exec_op(struct nand_chip *this,
+			   const struct nand_operation *op,
+			   bool check_only)
+{
+	struct doc_priv *doc = nand_get_controller_data(this);
+	unsigned int i;
+
+	if (check_only)
+		return true;
+
+	doc->curchip = op->cs % doc->chips_per_floor;
+	doc->curfloor = op->cs / doc->chips_per_floor;
+
+	WriteDOC(doc->curfloor, doc->virtadr, FloorSelect);
+	WriteDOC(doc->curchip, doc->virtadr, CDSNDeviceSelect);
+
+	/* Assert CE pin */
+	doc200x_write_control(doc, CDSN_CTRL_CE);
+
+	for (i = 0; i < op->ninstrs; i++)
+		doc200x_exec_instr(this, &op->instrs[i]);
+
+	/* De-assert CE pin */
+	doc200x_write_control(doc, 0);
+
+	return 0;
+}
+
+static void doc2001plus_write_pipe_term(struct doc_priv *doc)
+{
+	WriteDOC(0x00, doc->virtadr, Mplus_WritePipeTerm);
+	WriteDOC(0x00, doc->virtadr, Mplus_WritePipeTerm);
+}
+
+static void doc2001plus_exec_instr(struct nand_chip *this,
+				   const struct nand_op_instr *instr)
+{
+	struct doc_priv *doc = nand_get_controller_data(this);
+	unsigned int i;
+
+	switch (instr->type) {
+	case NAND_OP_CMD_INSTR:
+		WriteDOC(instr->ctx.cmd.opcode, doc->virtadr, Mplus_FlashCmd);
+		doc2001plus_write_pipe_term(doc);
+		break;
+
+	case NAND_OP_ADDR_INSTR:
+		for (i = 0; i < instr->ctx.addr.naddrs; i++) {
+			u8 addr = instr->ctx.addr.addrs[i];
+
+			WriteDOC(addr, doc->virtadr, Mplus_FlashAddress);
+		}
+		doc2001plus_write_pipe_term(doc);
+		/* deassert ALE */
+		WriteDOC(0, doc->virtadr, Mplus_FlashControl);
+		break;
+
+	case NAND_OP_DATA_IN_INSTR:
+		doc2001plus_readbuf(this, instr->ctx.data.buf.in,
+				    instr->ctx.data.len);
+		break;
+	case NAND_OP_DATA_OUT_INSTR:
+		doc2001plus_writebuf(this, instr->ctx.data.buf.out,
+				     instr->ctx.data.len);
+		doc2001plus_write_pipe_term(doc);
+		break;
+	case NAND_OP_WAITRDY_INSTR:
+		DoC_WaitReady(doc);
+		break;
+	}
+
+	if (instr->delay_ns)
+		ndelay(instr->delay_ns);
+}
+
+static int doc2001plus_exec_op(struct nand_chip *this,
+			       const struct nand_operation *op,
+			       bool check_only)
+{
+	struct doc_priv *doc = nand_get_controller_data(this);
+	unsigned int i;
+
+	if (check_only)
+		return true;
+
+	doc->curchip = op->cs % doc->chips_per_floor;
+	doc->curfloor = op->cs / doc->chips_per_floor;
+
+	/* Assert ChipEnable and deassert WriteProtect */
+	WriteDOC(DOC_FLASH_CE, doc->virtadr, Mplus_FlashSelect);
+
+	for (i = 0; i < op->ninstrs; i++)
+		doc2001plus_exec_instr(this, &op->instrs[i]);
+
+	/* De-assert ChipEnable */
+	WriteDOC(0, doc->virtadr, Mplus_FlashSelect);
+
+	return 0;
+}
+
 static void doc2001plus_command(struct nand_chip *this, unsigned command,
 				int column, int page_addr)
 {
@@ -1390,6 +1557,14 @@ static inline int __init doc2001plus_init(struct mtd_info *mtd)
 	return 1;
 }
 
+static const struct nand_controller_ops doc200x_ops = {
+	.exec_op = doc200x_exec_op,
+};
+
+static const struct nand_controller_ops doc2001plus_ops = {
+	.exec_op = doc2001plus_exec_op,
+};
+
 static int __init doc_probe(unsigned long physadr)
 {
 	struct nand_chip *nand = NULL;
@@ -1533,7 +1708,6 @@ static int __init doc_probe(unsigned long physadr)
 		goto fail;
 	}
 
-
 	/*
 	 * Allocate a RS codec instance
 	 *
@@ -1552,6 +1726,11 @@ static int __init doc_probe(unsigned long physadr)
 	}
 
 	nand_controller_init(&doc->base);
+	if (ChipID == DOC_ChipID_DocMilPlus16)
+		doc->base.ops = &doc2001plus_ops;
+	else
+		doc->base.ops = &doc200x_ops;
+
 	mtd			= nand_to_mtd(nand);
 	nand->bbt_td		= (struct nand_bbt_descr *) (doc + 1);
 	nand->bbt_md		= nand->bbt_td + 1;