mtd: rawnand: brcmnand: driver and doc updates

index 2e9c2e2d9c9f..69709419516a 100644
@@ -272,6 +272,7 @@ struct brcmnand_controller {
 	const unsigned int	*page_sizes;
 	unsigned int		page_size_shift;
 	unsigned int		max_oob;
+	u32			ecc_level_shift;
 	u32			features;
 
 	/* for low-power standby/resume only */

@@ -596,6 +597,34 @@ enum {
 	INTFC_CTLR_READY		= BIT(31),
 };
 
+/***********************************************************************
+ * NAND ACC CONTROL bitfield
+ *
+ * Some bits have remained constant throughout hardware revision, while
+ * others have shifted around.
+ ***********************************************************************/
+
+/* Constant for all versions (where supported) */
+enum {
+	/* See BRCMNAND_HAS_CACHE_MODE */
+	ACC_CONTROL_CACHE_MODE				= BIT(22),
+
+	/* See BRCMNAND_HAS_PREFETCH */
+	ACC_CONTROL_PREFETCH				= BIT(23),
+
+	ACC_CONTROL_PAGE_HIT				= BIT(24),
+	ACC_CONTROL_WR_PREEMPT				= BIT(25),
+	ACC_CONTROL_PARTIAL_PAGE			= BIT(26),
+	ACC_CONTROL_RD_ERASED				= BIT(27),
+	ACC_CONTROL_FAST_PGM_RDIN			= BIT(28),
+	ACC_CONTROL_WR_ECC				= BIT(30),
+	ACC_CONTROL_RD_ECC				= BIT(31),
+
+	ACC_CONTROL_ECC_SHIFT				= 16,
+	/* Only for v7.2 */
+	ACC_CONTROL_ECC_EXT_SHIFT			= 13,
+};
+
 static inline bool brcmnand_non_mmio_ops(struct brcmnand_controller *ctrl)
 {
 #if IS_ENABLED(CONFIG_MTD_NAND_BRCMNAND_BCMA)

@@ -737,6 +766,12 @@ static int brcmnand_revision_init(struct brcmnand_controller *ctrl)
 	else if (of_property_read_bool(ctrl->dev->of_node, "brcm,nand-has-wp"))
 		ctrl->features |= BRCMNAND_HAS_WP;
 
+	/* v7.2 has different ecc level shift in the acc register */
+	if (ctrl->nand_version == 0x0702)
+		ctrl->ecc_level_shift = ACC_CONTROL_ECC_EXT_SHIFT;
+	else
+		ctrl->ecc_level_shift = ACC_CONTROL_ECC_SHIFT;
+
 	return 0;
 }
 

@@ -931,30 +966,6 @@ static inline int brcmnand_cmd_shift(struct brcmnand_controller *ctrl)
 	return 0;
 }
 
-/***********************************************************************
- * NAND ACC CONTROL bitfield
- *
- * Some bits have remained constant throughout hardware revision, while
- * others have shifted around.
- ***********************************************************************/
-
-/* Constant for all versions (where supported) */
-enum {
-	/* See BRCMNAND_HAS_CACHE_MODE */
-	ACC_CONTROL_CACHE_MODE				= BIT(22),
-
-	/* See BRCMNAND_HAS_PREFETCH */
-	ACC_CONTROL_PREFETCH				= BIT(23),
-
-	ACC_CONTROL_PAGE_HIT				= BIT(24),
-	ACC_CONTROL_WR_PREEMPT				= BIT(25),
-	ACC_CONTROL_PARTIAL_PAGE			= BIT(26),
-	ACC_CONTROL_RD_ERASED				= BIT(27),
-	ACC_CONTROL_FAST_PGM_RDIN			= BIT(28),
-	ACC_CONTROL_WR_ECC				= BIT(30),
-	ACC_CONTROL_RD_ECC				= BIT(31),
-};
-
 static inline u32 brcmnand_spare_area_mask(struct brcmnand_controller *ctrl)
 {
 	if (ctrl->nand_version == 0x0702)

@@ -967,18 +978,15 @@ static inline u32 brcmnand_spare_area_mask(struct brcmnand_controller *ctrl)
 		return GENMASK(4, 0);
 }
 
-#define NAND_ACC_CONTROL_ECC_SHIFT	16
-#define NAND_ACC_CONTROL_ECC_EXT_SHIFT	13
-
 static inline u32 brcmnand_ecc_level_mask(struct brcmnand_controller *ctrl)
 {
 	u32 mask = (ctrl->nand_version >= 0x0600) ? 0x1f : 0x0f;
 
-	mask <<= NAND_ACC_CONTROL_ECC_SHIFT;
+	mask <<= ACC_CONTROL_ECC_SHIFT;
 
 	/* v7.2 includes additional ECC levels */
-	if (ctrl->nand_version >= 0x0702)
-		mask |= 0x7 << NAND_ACC_CONTROL_ECC_EXT_SHIFT;
+	if (ctrl->nand_version == 0x0702)
+		mask |= 0x7 << ACC_CONTROL_ECC_EXT_SHIFT;
 
 	return mask;
 }

@@ -992,8 +1000,8 @@ static void brcmnand_set_ecc_enabled(struct brcmnand_host *host, int en)
 
 	if (en) {
 		acc_control |= ecc_flags; /* enable RD/WR ECC */
-		acc_control |= host->hwcfg.ecc_level
-			       << NAND_ACC_CONTROL_ECC_SHIFT;
+		acc_control &= ~brcmnand_ecc_level_mask(ctrl);
+		acc_control |= host->hwcfg.ecc_level << ctrl->ecc_level_shift;
 	} else {
 		acc_control &= ~ecc_flags; /* disable RD/WR ECC */
 		acc_control &= ~brcmnand_ecc_level_mask(ctrl);

@@ -2561,7 +2569,7 @@ static int brcmnand_set_cfg(struct brcmnand_host *host,
 	tmp &= ~brcmnand_ecc_level_mask(ctrl);
 	tmp &= ~brcmnand_spare_area_mask(ctrl);
 	if (ctrl->nand_version >= 0x0302) {
-		tmp |= cfg->ecc_level << NAND_ACC_CONTROL_ECC_SHIFT;
+		tmp |= cfg->ecc_level << ctrl->ecc_level_shift;
 		tmp |= cfg->spare_area_size;
 	}
 	nand_writereg(ctrl, acc_control_offs, tmp);

index 69709419516a..37c2c7cfa00e 100644
@@ -1080,6 +1080,14 @@ static int bcmnand_ctrl_poll_status(struct brcmnand_controller *ctrl,
 		cpu_relax();
 	} while (time_after(limit, jiffies));
 
+	/*
+	 * do a final check after time out in case CPU is busy and driver does
+	 * not get the enough time to poll to avoid false alarm
+	 */
+	val = brcmnand_read_reg(ctrl, BRCMNAND_INTFC_STATUS);
+	if ((val & mask) == expected_val)
+		return 0;
+
 	dev_warn(ctrl->dev, "timeout on status poll (expected %x got %x)\n",
 		 expected_val, val & mask);
 

index 37c2c7cfa00e..ea03104692bf 100644
@@ -1608,7 +1608,17 @@ static void brcmnand_send_cmd(struct brcmnand_host *host, int cmd)
 
 	dev_dbg(ctrl->dev, "send native cmd %d addr 0x%llx\n", cmd, cmd_addr);
 
-	BUG_ON(ctrl->cmd_pending != 0);
+	/*
+	 * If we came here through _panic_write and there is a pending
+	 * command, try to wait for it. If it times out, rather than
+	 * hitting BUG_ON, just return so we don't crash while crashing.
+	 */
+	if (oops_in_progress) {
+		if (ctrl->cmd_pending &&
+			bcmnand_ctrl_poll_status(ctrl, NAND_CTRL_RDY, NAND_CTRL_RDY, 0))
+			return;
+	} else
+		BUG_ON(ctrl->cmd_pending != 0);
 	ctrl->cmd_pending = cmd;
 
 	ret = bcmnand_ctrl_poll_status(ctrl, NAND_CTRL_RDY, NAND_CTRL_RDY, 0);

index ea03104692bf..82e8434856c9 100644
@@ -1477,19 +1477,28 @@ static int write_oob_to_regs(struct brcmnand_controller *ctrl, int i,
 			     const u8 *oob, int sas, int sector_1k)
 {
 	int tbytes = sas << sector_1k;
-	int j;
+	int j, k = 0;
+	u32 last = 0xffffffff;
+	u8 *plast = (u8 *)&last;
 
 	/* Adjust OOB values for 1K sector size */
 	if (sector_1k && (i & 0x01))
 		tbytes = max(0, tbytes - (int)ctrl->max_oob);
 	tbytes = min_t(int, tbytes, ctrl->max_oob);
 
-	for (j = 0; j < tbytes; j += 4)
+	for (j = 0; (j + 3) < tbytes; j += 4)
 		oob_reg_write(ctrl, j,
 				(oob[j + 0] << 24) |
 				(oob[j + 1] << 16) |
 				(oob[j + 2] <<  8) |
 				(oob[j + 3] <<  0));
+
+	while (j < tbytes)
+		plast[k++] = oob[j++];
+
+	if (tbytes & 0x3)
+		oob_reg_write(ctrl, (tbytes & ~0x3), cpu_to_be32(last));
+
 	return tbytes;
 }