[PATCH v6] mtd: rawnand: brcmnand: legacy exec_op implementation

["Álvaro Fernández Rojas" <noltari@gmail.com>]

Commit 3c8260ce7663 ("mtd: rawnand: brcmnand: exec_op implementation")
removed legacy interface functions, breaking < v5.0 controllers support.
In order to fix older controllers we need to add an alternative exec_op
implementation which doesn't rely on low level registers.

Fixes: 3c8260ce7663 ("mtd: rawnand: brcmnand: exec_op implementation")
Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
Reviewed-by: David Regan <dregan@broadcom.com>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Reviewed-by: William Zhang <william.zhang@broadcom.com>
---
 drivers/mtd/nand/raw/brcmnand/brcmnand.c | 223 ++++++++++++++++++++++-
 1 file changed, 216 insertions(+), 7 deletions(-)

 v6: add changes requested by David Regan:
  - add braces in flash_cache for loop.

 v5: add changes requested by Miquèl Raynal:
  - Mention and explain legacy in native_cmd_conv.
  - EOPNOTSUPP instead of EINVAL for instr->type else.
  - Implement missing check_only functionality.

 v4: add changes requested by Jonas Gorski:
  - Add missing breaks in brcmnand_exec_instructions_legacy.
  - Restore missing ret assignment in brcmnand_exec_op.

 v3: add changes requested by Florian and other improvements:
  - Add associative array for native command conversion.
  - Add function pointer to brcmnand_controller for exec_instr
    functionality.
  - Fix CMD_BLOCK_ERASE address.
  - Drop NAND_CMD_READOOB support.

 v2: multiple improvements:
  - Use proper native commands for checks.
  - Fix NAND_CMD_PARAM/NAND_CMD_RNDOUT addr calculation.
  - Remove host->last_addr usage.
  - Remove sector_size_1k since it only applies to v5.0+ controllers.
  - Remove brcmnand_wp since it doesn't exist for < v5.0 controllers.
  - Use j instead of i for flash_cache loop.

diff --git a/drivers/mtd/nand/raw/brcmnand/brcmnand.c b/drivers/mtd/nand/raw/brcmnand/brcmnand.c
index b43281b8204f6..610e8557acafe 100644
--- a/drivers/mtd/nand/raw/brcmnand/brcmnand.c
+++ b/drivers/mtd/nand/raw/brcmnand/brcmnand.c
@@ -65,6 +65,7 @@ module_param(wp_on, int, 0444);
 #define CMD_PARAMETER_READ		0x0e
 #define CMD_PARAMETER_CHANGE_COL	0x0f
 #define CMD_LOW_LEVEL_OP		0x10
+#define CMD_NOT_SUPPORTED		0xff
 
 struct brcm_nand_dma_desc {
 	u32 next_desc;
@@ -199,6 +200,30 @@ static const u16 flash_dma_regs_v4[] = {
 	[FLASH_DMA_CURRENT_DESC_EXT]	= 0x34,
 };
 
+/* Native command conversion for legacy controllers (< v5.0) */
+static const u8 native_cmd_conv[] = {
+	[NAND_CMD_READ0]	= CMD_NOT_SUPPORTED,
+	[NAND_CMD_READ1]	= CMD_NOT_SUPPORTED,
+	[NAND_CMD_RNDOUT]	= CMD_PARAMETER_CHANGE_COL,
+	[NAND_CMD_PAGEPROG]	= CMD_NOT_SUPPORTED,
+	[NAND_CMD_READOOB]	= CMD_NOT_SUPPORTED,
+	[NAND_CMD_ERASE1]	= CMD_BLOCK_ERASE,
+	[NAND_CMD_STATUS]	= CMD_NOT_SUPPORTED,
+	[NAND_CMD_SEQIN]	= CMD_NOT_SUPPORTED,
+	[NAND_CMD_RNDIN]	= CMD_NOT_SUPPORTED,
+	[NAND_CMD_READID]	= CMD_DEVICE_ID_READ,
+	[NAND_CMD_ERASE2]	= CMD_NULL,
+	[NAND_CMD_PARAM]	= CMD_PARAMETER_READ,
+	[NAND_CMD_GET_FEATURES]	= CMD_NOT_SUPPORTED,
+	[NAND_CMD_SET_FEATURES]	= CMD_NOT_SUPPORTED,
+	[NAND_CMD_RESET]	= CMD_NOT_SUPPORTED,
+	[NAND_CMD_READSTART]	= CMD_NOT_SUPPORTED,
+	[NAND_CMD_READCACHESEQ]	= CMD_NOT_SUPPORTED,
+	[NAND_CMD_READCACHEEND]	= CMD_NOT_SUPPORTED,
+	[NAND_CMD_RNDOUTSTART]	= CMD_NULL,
+	[NAND_CMD_CACHEDPROG]	= CMD_NOT_SUPPORTED,
+};
+
 /* Controller feature flags */
 enum {
 	BRCMNAND_HAS_1K_SECTORS			= BIT(0),
@@ -237,6 +262,12 @@ struct brcmnand_controller {
 	/* List of NAND hosts (one for each chip-select) */
 	struct list_head host_list;
 
+	/* Functions to be called from exec_op */
+	int (*check_instr)(struct nand_chip *chip,
+			   const struct nand_operation *op);
+	int (*exec_instr)(struct nand_chip *chip,
+			  const struct nand_operation *op);
+
 	/* EDU info, per-transaction */
 	const u16               *edu_offsets;
 	void __iomem            *edu_base;
@@ -2478,18 +2509,191 @@ static int brcmnand_op_is_reset(const struct nand_operation *op)
 	return 0;
 }
 
+static int brcmnand_check_instructions(struct nand_chip *chip,
+				       const struct nand_operation *op)
+{
+	return 0;
+}
+
+static int brcmnand_exec_instructions(struct nand_chip *chip,
+				      const struct nand_operation *op)
+{
+	struct brcmnand_host *host = nand_get_controller_data(chip);
+	unsigned int i;
+	int ret = 0;
+
+	for (i = 0; i < op->ninstrs; i++) {
+		ret = brcmnand_exec_instr(host, i, op);
+		if (ret)
+			break;
+	}
+
+	return ret;
+}
+
+static int brcmnand_check_instructions_legacy(struct nand_chip *chip,
+					      const struct nand_operation *op)
+{
+	const struct nand_op_instr *instr;
+	unsigned int i;
+	u8 cmd;
+
+	for (i = 0; i < op->ninstrs; i++) {
+		instr = &op->instrs[i];
+
+		switch (instr->type) {
+		case NAND_OP_CMD_INSTR:
+			cmd = native_cmd_conv[instr->ctx.cmd.opcode];
+			if (cmd == CMD_NOT_SUPPORTED)
+				return -EOPNOTSUPP;
+			break;
+		case NAND_OP_ADDR_INSTR:
+		case NAND_OP_DATA_IN_INSTR:
+		case NAND_OP_WAITRDY_INSTR:
+			break;
+		default:
+			return -EOPNOTSUPP;
+		}
+	}
+
+	return 0;
+}
+
+static int brcmnand_exec_instructions_legacy(struct nand_chip *chip,
+					     const struct nand_operation *op)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	struct brcmnand_host *host = nand_get_controller_data(chip);
+	struct brcmnand_controller *ctrl = host->ctrl;
+	const struct nand_op_instr *instr;
+	unsigned int i, j;
+	u8 cmd = CMD_NULL, last_cmd = CMD_NULL;
+	int ret = 0;
+	u64 last_addr;
+
+	for (i = 0; i < op->ninstrs; i++) {
+		instr = &op->instrs[i];
+
+		if (instr->type == NAND_OP_CMD_INSTR) {
+			cmd = native_cmd_conv[instr->ctx.cmd.opcode];
+			if (cmd == CMD_NOT_SUPPORTED) {
+				dev_err(ctrl->dev, "unsupported cmd=%d\n",
+					instr->ctx.cmd.opcode);
+				ret = -EOPNOTSUPP;
+				break;
+			}
+		} else if (instr->type == NAND_OP_ADDR_INSTR) {
+			u64 addr = 0;
+
+			if (cmd == CMD_NULL)
+				continue;
+
+			if (instr->ctx.addr.naddrs > 8) {
+				dev_err(ctrl->dev, "unsupported naddrs=%u\n",
+					instr->ctx.addr.naddrs);
+				ret = -EOPNOTSUPP;
+				break;
+			}
+
+			for (j = 0; j < instr->ctx.addr.naddrs; j++)
+				addr |= (instr->ctx.addr.addrs[j]) << (j << 3);
+
+			if (cmd == CMD_BLOCK_ERASE)
+				addr <<= chip->page_shift;
+			else if (cmd == CMD_PARAMETER_CHANGE_COL)
+				addr &= ~((u64)(FC_BYTES - 1));
+
+			brcmnand_set_cmd_addr(mtd, addr);
+			brcmnand_send_cmd(host, cmd);
+			last_addr = addr;
+			last_cmd = cmd;
+			cmd = CMD_NULL;
+			brcmnand_waitfunc(chip);
+
+			if (last_cmd == CMD_PARAMETER_READ ||
+			    last_cmd == CMD_PARAMETER_CHANGE_COL) {
+				/* Copy flash cache word-wise */
+				u32 *flash_cache = (u32 *)ctrl->flash_cache;
+
+				brcmnand_soc_data_bus_prepare(ctrl->soc, true);
+
+				/*
+				 * Must cache the FLASH_CACHE now, since changes in
+				 * SECTOR_SIZE_1K may invalidate it
+				 */
+				for (j = 0; j < FC_WORDS; j++) {
+					/*
+					 * Flash cache is big endian for parameter pages, at
+					 * least on STB SoCs
+					 */
+					flash_cache[j] = be32_to_cpu(brcmnand_read_fc(ctrl, j));
+				}
+
+				brcmnand_soc_data_bus_unprepare(ctrl->soc, true);
+			}
+		} else if (instr->type == NAND_OP_DATA_IN_INSTR) {
+			u8 *in = instr->ctx.data.buf.in;
+
+			if (last_cmd == CMD_DEVICE_ID_READ) {
+				u32 val;
+
+				if (instr->ctx.data.len > 8) {
+					dev_err(ctrl->dev, "unsupported len=%u\n",
+						instr->ctx.data.len);
+					ret = -EOPNOTSUPP;
+					break;
+				}
+
+				for (j = 0; j < instr->ctx.data.len; j++) {
+					if (j == 0)
+						val = brcmnand_read_reg(ctrl, BRCMNAND_ID);
+					else if (j == 4)
+						val = brcmnand_read_reg(ctrl, BRCMNAND_ID_EXT);
+
+					in[j] = (val >> (24 - ((j % 4) << 3))) & 0xff;
+				}
+			} else if (last_cmd == CMD_PARAMETER_READ ||
+				   last_cmd == CMD_PARAMETER_CHANGE_COL) {
+				u64 addr;
+				u32 offs;
+
+				for (j = 0; j < instr->ctx.data.len; j++) {
+					addr = last_addr + j;
+					offs = addr & (FC_BYTES - 1);
+
+					if (j > 0 && offs == 0)
+						nand_change_read_column_op(chip, addr, NULL, 0,
+									   false);
+
+					in[j] = ctrl->flash_cache[offs];
+				}
+			}
+		} else if (instr->type == NAND_OP_WAITRDY_INSTR) {
+			ret = bcmnand_ctrl_poll_status(host, NAND_CTRL_RDY, NAND_CTRL_RDY, 0);
+			if (ret)
+				break;
+		} else {
+			dev_err(ctrl->dev, "unsupported instruction type: %d\n", instr->type);
+			ret = -EOPNOTSUPP;
+			break;
+		}
+	}
+
+	return ret;
+}
+
 static int brcmnand_exec_op(struct nand_chip *chip,
 			    const struct nand_operation *op,
 			    bool check_only)
 {
 	struct brcmnand_host *host = nand_get_controller_data(chip);
+	struct brcmnand_controller *ctrl = host->ctrl;
 	struct mtd_info *mtd = nand_to_mtd(chip);
 	u8 *status;
-	unsigned int i;
 	int ret = 0;
 
 	if (check_only)
-		return 0;
+		return ctrl->check_instr(chip, op);
 
 	if (brcmnand_op_is_status(op)) {
 		status = op->instrs[1].ctx.data.buf.in;
@@ -2513,11 +2717,7 @@ static int brcmnand_exec_op(struct nand_chip *chip,
 	if (op->deassert_wp)
 		brcmnand_wp(mtd, 0);
 
-	for (i = 0; i < op->ninstrs; i++) {
-		ret = brcmnand_exec_instr(host, i, op);
-		if (ret)
-			break;
-	}
+	ret = ctrl->exec_instr(chip, op);
 
 	if (op->deassert_wp)
 		brcmnand_wp(mtd, 1);
@@ -3130,6 +3330,15 @@ int brcmnand_probe(struct platform_device *pdev, struct brcmnand_soc *soc)
 	if (ret)
 		goto err;
 
+	/* Only v5.0+ controllers have low level ops support */
+	if (ctrl->nand_version >= 0x0500) {
+		ctrl->check_instr = brcmnand_check_instructions;
+		ctrl->exec_instr = brcmnand_exec_instructions;
+	} else {
+		ctrl->check_instr = brcmnand_check_instructions_legacy;
+		ctrl->exec_instr = brcmnand_exec_instructions_legacy;
+	}
+
 	/*
 	 * Most chips have this cache at a fixed offset within 'nand' block.
 	 * Some must specify this region separately.
-- 
2.39.5


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