Merge tag 'spi-nor/for-6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux into mtd/next

SPI NOR introduces byte swap support for 8D-8D-8D mode and a user for
it: macronix. SPI NOR flashes may swap the bytes on a 16-bit boundary
when configured in Octal DTR mode. For such cases the byte order is
propagated through SPI MEM to the SPI controllers so that the controllers
swap the bytes back at runtime. This avoids breaking the boot sequence
because of the endianness problems that appear when the bootloaders use
1-1-1 and the kernel uses 8D-8D-8D with byte swap support. Along with the
SPI MEM byte swap support we queue a patch for the SPI MXIC controller
that swaps the bytes back at runtime.

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Author: miquelraynal

drivers/mtd/spi-nor/core.c

@@ -89,7 +89,7 @@ void spi_nor_spimem_setup_op(const struct spi_nor *nor,
 		op->addr.buswidth = spi_nor_get_protocol_addr_nbits(proto);
 
 	if (op->dummy.nbytes)
-		op->dummy.buswidth = spi_nor_get_protocol_addr_nbits(proto);
+		op->dummy.buswidth = spi_nor_get_protocol_data_nbits(proto);
 
 	if (op->data.nbytes)
 		op->data.buswidth = spi_nor_get_protocol_data_nbits(proto);
@@ -113,6 +113,9 @@ void spi_nor_spimem_setup_op(const struct spi_nor *nor,
 		op->cmd.opcode = (op->cmd.opcode << 8) | ext;
 		op->cmd.nbytes = 2;
 	}
+
+	if (proto == SNOR_PROTO_8_8_8_DTR && nor->flags & SNOR_F_SWAP16)
+		op->data.swap16 = true;
 }
 
 /**

drivers/mtd/spi-nor/core.h

@@ -140,6 +140,7 @@ enum spi_nor_option_flags {
 	SNOR_F_RWW		= BIT(14),
 	SNOR_F_ECC		= BIT(15),
 	SNOR_F_NO_WP		= BIT(16),
+	SNOR_F_SWAP16		= BIT(17),
 };
 
 struct spi_nor_read_command {

drivers/mtd/spi-nor/macronix.c

@@ -8,6 +8,23 @@
 
 #include "core.h"
 
+#define MXIC_NOR_OP_RD_CR2	0x71		/* Read configuration register 2 opcode */
+#define MXIC_NOR_OP_WR_CR2	0x72		/* Write configuration register 2 opcode */
+#define MXIC_NOR_ADDR_CR2_MODE	0x00000000	/* CR2 address for setting spi/sopi/dopi mode */
+#define MXIC_NOR_ADDR_CR2_DC	0x00000300	/* CR2 address for setting dummy cycles */
+#define MXIC_NOR_REG_DOPI_EN	0x2		/* Enable Octal DTR */
+#define MXIC_NOR_REG_SPI_EN	0x0		/* Enable SPI */
+
+/* Convert dummy cycles to bit pattern */
+#define MXIC_NOR_REG_DC(p) \
+	((20 - (p)) >> 1)
+
+#define MXIC_NOR_WR_CR2(addr, ndata, buf)			\
+	SPI_MEM_OP(SPI_MEM_OP_CMD(MXIC_NOR_OP_WR_CR2, 0),	\
+		   SPI_MEM_OP_ADDR(4, addr, 0),			\
+		   SPI_MEM_OP_NO_DUMMY,				\
+		   SPI_MEM_OP_DATA_OUT(ndata, buf, 0))
+
 static int
 mx25l25635_post_bfpt_fixups(struct spi_nor *nor,
 			    const struct sfdp_parameter_header *bfpt_header,
@@ -182,9 +199,88 @@ static const struct flash_info macronix_nor_parts[] = {
 		.name = "mx25l3255e",
 		.size = SZ_4M,
 		.no_sfdp_flags = SECT_4K,
-	}
+	},
+	/*
+	 * This spares us of adding new flash entries for flashes that can be
+	 * initialized solely based on the SFDP data, but still need the
+	 * manufacturer hooks to set parameters that can't be discovered at SFDP
+	 * parsing time.
+	 */
+	{ .id = SNOR_ID(0xc2) }
 };
 
+static int macronix_nor_octal_dtr_en(struct spi_nor *nor)
+{
+	struct spi_mem_op op;
+	u8 *buf = nor->bouncebuf, i;
+	int ret;
+
+	/* Use dummy cycles which is parse by SFDP and convert to bit pattern. */
+	buf[0] = MXIC_NOR_REG_DC(nor->params->reads[SNOR_CMD_READ_8_8_8_DTR].num_wait_states);
+	op = (struct spi_mem_op)MXIC_NOR_WR_CR2(MXIC_NOR_ADDR_CR2_DC, 1, buf);
+	ret = spi_nor_write_any_volatile_reg(nor, &op, nor->reg_proto);
+	if (ret)
+		return ret;
+
+	/* Set the octal and DTR enable bits. */
+	buf[0] = MXIC_NOR_REG_DOPI_EN;
+	op = (struct spi_mem_op)MXIC_NOR_WR_CR2(MXIC_NOR_ADDR_CR2_MODE, 1, buf);
+	ret = spi_nor_write_any_volatile_reg(nor, &op, nor->reg_proto);
+	if (ret)
+		return ret;
+
+	/* Read flash ID to make sure the switch was successful. */
+	ret = spi_nor_read_id(nor, 4, 4, buf, SNOR_PROTO_8_8_8_DTR);
+	if (ret) {
+		dev_dbg(nor->dev, "error %d reading JEDEC ID after enabling 8D-8D-8D mode\n", ret);
+		return ret;
+	}
+
+	/* Macronix SPI-NOR flash 8D-8D-8D read ID would get 6 bytes data A-A-B-B-C-C */
+	for (i = 0; i < nor->info->id->len; i++)
+		if (buf[i * 2] != buf[(i * 2) + 1] || buf[i * 2] != nor->info->id->bytes[i])
+			return -EINVAL;
+
+	return 0;
+}
+
+static int macronix_nor_octal_dtr_dis(struct spi_nor *nor)
+{
+	struct spi_mem_op op;
+	u8 *buf = nor->bouncebuf;
+	int ret;
+
+	/*
+	 * The register is 1-byte wide, but 1-byte transactions are not
+	 * allowed in 8D-8D-8D mode. Since there is no register at the
+	 * next location, just initialize the value to 0 and let the
+	 * transaction go on.
+	 */
+	buf[0] = MXIC_NOR_REG_SPI_EN;
+	buf[1] = 0x0;
+	op = (struct spi_mem_op)MXIC_NOR_WR_CR2(MXIC_NOR_ADDR_CR2_MODE, 2, buf);
+	ret = spi_nor_write_any_volatile_reg(nor, &op, SNOR_PROTO_8_8_8_DTR);
+	if (ret)
+		return ret;
+
+	/* Read flash ID to make sure the switch was successful. */
+	ret = spi_nor_read_id(nor, 0, 0, buf, SNOR_PROTO_1_1_1);
+	if (ret) {
+		dev_dbg(nor->dev, "error %d reading JEDEC ID after disabling 8D-8D-8D mode\n", ret);
+		return ret;
+	}
+
+	if (memcmp(buf, nor->info->id->bytes, nor->info->id->len))
+		return -EINVAL;
+
+	return 0;
+}
+
+static int macronix_nor_set_octal_dtr(struct spi_nor *nor, bool enable)
+{
+	return enable ? macronix_nor_octal_dtr_en(nor) : macronix_nor_octal_dtr_dis(nor);
+}
+
 static void macronix_nor_default_init(struct spi_nor *nor)
 {
 	nor->params->quad_enable = spi_nor_sr1_bit6_quad_enable;
@@ -194,6 +290,7 @@ static int macronix_nor_late_init(struct spi_nor *nor)
 {
 	if (!nor->params->set_4byte_addr_mode)
 		nor->params->set_4byte_addr_mode = spi_nor_set_4byte_addr_mode_en4b_ex4b;
+	nor->params->set_octal_dtr = macronix_nor_set_octal_dtr;
 
 	return 0;
 }

drivers/mtd/spi-nor/sfdp.c

@@ -671,6 +671,10 @@ static int spi_nor_parse_bfpt(struct spi_nor *nor,
 		return -EOPNOTSUPP;
 	}
 
+	/* Byte order in 8D-8D-8D mode */
+	if (bfpt.dwords[SFDP_DWORD(18)] & BFPT_DWORD18_BYTE_ORDER_SWAPPED)
+		nor->flags |= SNOR_F_SWAP16;
+
 	return spi_nor_post_bfpt_fixups(nor, bfpt_header, &bfpt);
 }
 

drivers/mtd/spi-nor/sfdp.h

@@ -130,6 +130,7 @@ struct sfdp_bfpt {
 #define BFPT_DWORD18_CMD_EXT_INV		(0x1UL << 29) /* Invert */
 #define BFPT_DWORD18_CMD_EXT_RES		(0x2UL << 29) /* Reserved */
 #define BFPT_DWORD18_CMD_EXT_16B		(0x3UL << 29) /* 16-bit opcode */
+#define BFPT_DWORD18_BYTE_ORDER_SWAPPED		BIT(31)	/* Byte order swapped in 8D-8D-8D mode */
 
 struct sfdp_parameter_header {
 	u8		id_lsb;

drivers/mtd/spi-nor/spansion.c

@@ -106,6 +106,7 @@ static int cypress_nor_sr_ready_and_clear_reg(struct spi_nor *nor, u64 addr)
 	int ret;
 
 	if (nor->reg_proto == SNOR_PROTO_8_8_8_DTR) {
+		op.addr.nbytes = nor->addr_nbytes;
 		op.dummy.nbytes = params->rdsr_dummy;
 		op.data.nbytes = 2;
 	}

drivers/mtd/spi-nor/winbond.c

@@ -129,6 +129,7 @@ static const struct flash_info winbond_nor_parts[] = {
 		.no_sfdp_flags = SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ,
 	}, {
 		.id = SNOR_ID(0xef, 0x40, 0x18),
+		/* Flavors w/ and w/o SFDP. */
 		.name = "w25q128",
 		.size = SZ_16M,
 		.flags = SPI_NOR_HAS_LOCK | SPI_NOR_HAS_TB,

drivers/spi/spi-mem.c

@@ -172,6 +172,9 @@ bool spi_mem_default_supports_op(struct spi_mem *mem,
 		if (!spi_mem_controller_is_capable(ctlr, dtr))
 			return false;
 
+		if (op->data.swap16 && !spi_mem_controller_is_capable(ctlr, swap16))
+			return false;
+
 		if (op->cmd.nbytes != 2)
 			return false;
 	} else {

drivers/spi/spi-mxic.c

@@ -294,7 +294,8 @@ static void mxic_spi_hw_init(struct mxic_spi *mxic)
 	       mxic->regs + HC_CFG);
 }
 
-static u32 mxic_spi_prep_hc_cfg(struct spi_device *spi, u32 flags)
+static u32 mxic_spi_prep_hc_cfg(struct spi_device *spi, u32 flags,
+				bool swap16)
 {
 	int nio = 1;
 
@@ -305,6 +306,11 @@ static u32 mxic_spi_prep_hc_cfg(struct spi_device *spi, u32 flags)
 	else if (spi->mode & (SPI_TX_DUAL | SPI_RX_DUAL))
 		nio = 2;
 
+	if (swap16)
+		flags &= ~HC_CFG_DATA_PASS;
+	else
+		flags |= HC_CFG_DATA_PASS;
+
 	return flags | HC_CFG_NIO(nio) |
 	       HC_CFG_TYPE(spi_get_chipselect(spi, 0), HC_CFG_TYPE_SPI_NOR) |
 	       HC_CFG_SLV_ACT(spi_get_chipselect(spi, 0)) | HC_CFG_IDLE_SIO_LVL(1);
@@ -397,7 +403,8 @@ static ssize_t mxic_spi_mem_dirmap_read(struct spi_mem_dirmap_desc *desc,
 	if (WARN_ON(offs + desc->info.offset + len > U32_MAX))
 		return -EINVAL;
 
-	writel(mxic_spi_prep_hc_cfg(desc->mem->spi, 0), mxic->regs + HC_CFG);
+	writel(mxic_spi_prep_hc_cfg(desc->mem->spi, 0, desc->info.op_tmpl.data.swap16),
+	       mxic->regs + HC_CFG);
 
 	writel(mxic_spi_mem_prep_op_cfg(&desc->info.op_tmpl, len),
 	       mxic->regs + LRD_CFG);
@@ -441,7 +448,8 @@ static ssize_t mxic_spi_mem_dirmap_write(struct spi_mem_dirmap_desc *desc,
 	if (WARN_ON(offs + desc->info.offset + len > U32_MAX))
 		return -EINVAL;
 
-	writel(mxic_spi_prep_hc_cfg(desc->mem->spi, 0), mxic->regs + HC_CFG);
+	writel(mxic_spi_prep_hc_cfg(desc->mem->spi, 0, desc->info.op_tmpl.data.swap16),
+	       mxic->regs + HC_CFG);
 
 	writel(mxic_spi_mem_prep_op_cfg(&desc->info.op_tmpl, len),
 	       mxic->regs + LWR_CFG);
@@ -518,7 +526,7 @@ static int mxic_spi_mem_exec_op(struct spi_mem *mem,
 	if (ret)
 		return ret;
 
-	writel(mxic_spi_prep_hc_cfg(mem->spi, HC_CFG_MAN_CS_EN),
+	writel(mxic_spi_prep_hc_cfg(mem->spi, HC_CFG_MAN_CS_EN, op->data.swap16),
 	       mxic->regs + HC_CFG);
 
 	writel(HC_EN_BIT, mxic->regs + HC_EN);
@@ -573,6 +581,7 @@ static const struct spi_controller_mem_ops mxic_spi_mem_ops = {
 static const struct spi_controller_mem_caps mxic_spi_mem_caps = {
 	.dtr = true,
 	.ecc = true,
+	.swap16 = true,
 };
 
 static void mxic_spi_set_cs(struct spi_device *spi, bool lvl)

include/linux/spi/spi-mem.h

@@ -90,6 +90,8 @@ enum spi_mem_data_dir {
  * @data.buswidth: number of IO lanes used to send/receive the data
  * @data.dtr: whether the data should be sent in DTR mode or not
  * @data.ecc: whether error correction is required or not
+ * @data.swap16: whether the byte order of 16-bit words is swapped when read
+ *		 or written in Octal DTR mode compared to STR mode.
  * @data.dir: direction of the transfer
  * @data.nbytes: number of data bytes to send/receive. Can be zero if the
  *		 operation does not involve transferring data
@@ -124,7 +126,8 @@ struct spi_mem_op {
 		u8 buswidth;
 		u8 dtr : 1;
 		u8 ecc : 1;
-		u8 __pad : 6;
+		u8 swap16 : 1;
+		u8 __pad : 5;
 		enum spi_mem_data_dir dir;
 		unsigned int nbytes;
 		union {
@@ -297,10 +300,13 @@ struct spi_controller_mem_ops {
  * struct spi_controller_mem_caps - SPI memory controller capabilities
  * @dtr: Supports DTR operations
  * @ecc: Supports operations with error correction
+ * @swap16: Supports swapping bytes on a 16 bit boundary when configured in
+ *	    Octal DTR
  */
 struct spi_controller_mem_caps {
 	bool dtr;
 	bool ecc;
+	bool swap16;
 };
 
 #define spi_mem_controller_is_capable(ctlr, cap)	\