[RFC PATCH v5 2/6] mtd: rawnand: meson: wait for command in polling mode

[Arseniy Krasnov]

This adds support of waiting for command completion in sofyware polling
mode. It is needed when ready/busy pin is not implemented in hardware.

Signed-off-by: Arseniy Krasnov <AVKrasnov@xxxxxxxxxxxxxx>
---
 drivers/mtd/nand/raw/meson_nand.c | 53 ++++++++++++++++++-------------
 1 file changed, 31 insertions(+), 22 deletions(-)

diff --git a/drivers/mtd/nand/raw/meson_nand.c b/drivers/mtd/nand/raw/meson_nand.c
index 9dd4a676497b..82a629025adc 100644
--- a/drivers/mtd/nand/raw/meson_nand.c
+++ b/drivers/mtd/nand/raw/meson_nand.c
@@ -179,6 +179,7 @@ struct meson_nfc {
 	u32 info_bytes;
 
 	unsigned long assigned_cs;
+	bool use_polling;
 };
 
 enum {
@@ -392,32 +393,38 @@ static void meson_nfc_set_data_oob(struct nand_chip *nand,
 	}
 }
 
-static int meson_nfc_queue_rb(struct meson_nfc *nfc, int timeout_ms)
+static int meson_nfc_queue_rb(struct nand_chip *nand, int timeout_ms)
 {
-	u32 cmd, cfg;
-	int ret = 0;
+	struct meson_nfc *nfc = nand_get_controller_data(nand);
 
-	meson_nfc_cmd_idle(nfc, nfc->timing.twb);
-	meson_nfc_drain_cmd(nfc);
-	meson_nfc_wait_cmd_finish(nfc, CMD_FIFO_EMPTY_TIMEOUT);
+	if (nfc->use_polling) {
+		return nand_soft_waitrdy(nand, timeout_ms);
+	} else {
+		u32 cmd, cfg;
+		int ret = 0;
 
-	cfg = readl(nfc->reg_base + NFC_REG_CFG);
-	cfg |= NFC_RB_IRQ_EN;
-	writel(cfg, nfc->reg_base + NFC_REG_CFG);
+		meson_nfc_cmd_idle(nfc, nfc->timing.twb);
+		meson_nfc_drain_cmd(nfc);
+		meson_nfc_wait_cmd_finish(nfc, CMD_FIFO_EMPTY_TIMEOUT);
 
-	reinit_completion(&nfc->completion);
+		cfg = readl(nfc->reg_base + NFC_REG_CFG);
+		cfg |= NFC_RB_IRQ_EN;
+		writel(cfg, nfc->reg_base + NFC_REG_CFG);
 
-	/* use the max erase time as the maximum clock for waiting R/B */
-	cmd = NFC_CMD_RB | NFC_CMD_RB_INT
-		| nfc->param.chip_select | nfc->timing.tbers_max;
-	writel(cmd, nfc->reg_base + NFC_REG_CMD);
+		reinit_completion(&nfc->completion);
 
-	ret = wait_for_completion_timeout(&nfc->completion,
-					  msecs_to_jiffies(timeout_ms));
-	if (ret == 0)
-		ret = -1;
+		/* use the max erase time as the maximum clock for waiting R/B */
+		cmd = NFC_CMD_RB | NFC_CMD_RB_INT
+			| nfc->param.chip_select | nfc->timing.tbers_max;
+		writel(cmd, nfc->reg_base + NFC_REG_CMD);
 
-	return ret;
+		ret = wait_for_completion_timeout(&nfc->completion,
+						  msecs_to_jiffies(timeout_ms));
+		if (ret == 0)
+			return -ETIMEDOUT;
+
+		return 0;
+	}
 }
 
 static void meson_nfc_set_user_byte(struct nand_chip *nand, u8 *oob_buf)
@@ -623,7 +630,7 @@ static int meson_nfc_rw_cmd_prepare_and_execute(struct nand_chip *nand,
 	if (in) {
 		nfc->cmdfifo.rw.cmd1 = cs | NFC_CMD_CLE | NAND_CMD_READSTART;
 		writel(nfc->cmdfifo.rw.cmd1, nfc->reg_base + NFC_REG_CMD);
-		meson_nfc_queue_rb(nfc, PSEC_TO_MSEC(sdr->tR_max));
+		meson_nfc_queue_rb(nand, PSEC_TO_MSEC(sdr->tR_max));
 	} else {
 		meson_nfc_cmd_idle(nfc, nfc->timing.tadl);
 	}
@@ -669,7 +676,7 @@ static int meson_nfc_write_page_sub(struct nand_chip *nand,
 
 	cmd = nfc->param.chip_select | NFC_CMD_CLE | NAND_CMD_PAGEPROG;
 	writel(cmd, nfc->reg_base + NFC_REG_CMD);
-	meson_nfc_queue_rb(nfc, PSEC_TO_MSEC(sdr->tPROG_max));
+	meson_nfc_queue_rb(nand, PSEC_TO_MSEC(sdr->tPROG_max));
 
 	meson_nfc_dma_buffer_release(nand, data_len, info_len, DMA_TO_DEVICE);
 
@@ -952,7 +959,7 @@ static int meson_nfc_exec_op(struct nand_chip *nand,
 			break;
 
 		case NAND_OP_WAITRDY_INSTR:
-			meson_nfc_queue_rb(nfc, instr->ctx.waitrdy.timeout_ms);
+			meson_nfc_queue_rb(nand, instr->ctx.waitrdy.timeout_ms);
 			if (instr->delay_ns)
 				meson_nfc_cmd_idle(nfc, delay_idle);
 			break;
@@ -1412,6 +1419,8 @@ static int meson_nfc_probe(struct platform_device *pdev)
 		return ret;
 	}
 
+	nfc->use_polling = of_property_read_bool(dev->of_node, "polling");
+
 	writel(0, nfc->reg_base + NFC_REG_CFG);
 	ret = devm_request_irq(dev, irq, meson_nfc_irq, 0, dev_name(dev), nfc);
 	if (ret) {
-- 
2.35.0