mtd: spi-nor: fsl-quadspi: add big-endian support

Add R/W functions for big- or little-endian registers:
The qSPI controller's endian is independent of the CPU core's endian.
So far, the qSPI have two versions for big-endian and little-endian.

Signed-off-by: Yuan Yao <yao.yuan@nxp.com>
Acked-by: Han xu <han.xu@freescale.com>
Acked-by: Han xu <han.xu@nxp.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

1 files changed, 97 insertions, 60 deletions

diff --git a/drivers/mtd/spi-nor/fsl-quadspi.c b/drivers/mtd/spi-nor/fsl-quadspi.c
index 54640f1eb3a1..04e8a93e1a3a 100644
--- a/drivers/mtd/spi-nor/fsl-quadspi.c
+++ b/drivers/mtd/spi-nor/fsl-quadspi.c
@@ -275,6 +275,7 @@ struct fsl_qspi {
 	u32 clk_rate;
 	unsigned int chip_base_addr; /* We may support two chips. */
 	bool has_second_chip;
+	bool big_endian;
 	struct mutex lock;
 	struct pm_qos_request pm_qos_req;
 };
@@ -300,6 +301,28 @@ static inline int needs_wakeup_wait_mode(struct fsl_qspi *q)
 }
 
 /*
+ * R/W functions for big- or little-endian registers:
+ * The qSPI controller's endian is independent of the CPU core's endian.
+ * So far, although the CPU core is little-endian but the qSPI have two
+ * versions for big-endian and little-endian.
+ */
+static void qspi_writel(struct fsl_qspi *q, u32 val, void __iomem *addr)
+{
+	if (q->big_endian)
+		iowrite32be(val, addr);
+	else
+		iowrite32(val, addr);
+}
+
+static u32 qspi_readl(struct fsl_qspi *q, void __iomem *addr)
+{
+	if (q->big_endian)
+		return ioread32be(addr);
+	else
+		return ioread32(addr);
+}
+
+/*
  * An IC bug makes us to re-arrange the 32-bit data.
  * The following chips, such as IMX6SLX, have fixed this bug.
  */
@@ -310,14 +333,14 @@ static inline u32 fsl_qspi_endian_xchg(struct fsl_qspi *q, u32 a)
 
 static inline void fsl_qspi_unlock_lut(struct fsl_qspi *q)
 {
-	writel(QUADSPI_LUTKEY_VALUE, q->iobase + QUADSPI_LUTKEY);
-	writel(QUADSPI_LCKER_UNLOCK, q->iobase + QUADSPI_LCKCR);
+	qspi_writel(q, QUADSPI_LUTKEY_VALUE, q->iobase + QUADSPI_LUTKEY);
+	qspi_writel(q, QUADSPI_LCKER_UNLOCK, q->iobase + QUADSPI_LCKCR);
 }
 
 static inline void fsl_qspi_lock_lut(struct fsl_qspi *q)
 {
-	writel(QUADSPI_LUTKEY_VALUE, q->iobase + QUADSPI_LUTKEY);
-	writel(QUADSPI_LCKER_LOCK, q->iobase + QUADSPI_LCKCR);
+	qspi_writel(q, QUADSPI_LUTKEY_VALUE, q->iobase + QUADSPI_LUTKEY);
+	qspi_writel(q, QUADSPI_LCKER_LOCK, q->iobase + QUADSPI_LCKCR);
 }
 
 static irqreturn_t fsl_qspi_irq_handler(int irq, void *dev_id)
@@ -326,8 +349,8 @@ static irqreturn_t fsl_qspi_irq_handler(int irq, void *dev_id)
 	u32 reg;
 
 	/* clear interrupt */
-	reg = readl(q->iobase + QUADSPI_FR);
-	writel(reg, q->iobase + QUADSPI_FR);
+	reg = qspi_readl(q, q->iobase + QUADSPI_FR);
+	qspi_writel(q, reg, q->iobase + QUADSPI_FR);
 
 	if (reg & QUADSPI_FR_TFF_MASK)
 		complete(&q->c);
@@ -348,7 +371,7 @@ static void fsl_qspi_init_lut(struct fsl_qspi *q)
 
 	/* Clear all the LUT table */
 	for (i = 0; i < QUADSPI_LUT_NUM; i++)
-		writel(0, base + QUADSPI_LUT_BASE + i * 4);
+		qspi_writel(q, 0, base + QUADSPI_LUT_BASE + i * 4);
 
 	/* Quad Read */
 	lut_base = SEQID_QUAD_READ * 4;
@@ -364,14 +387,15 @@ static void fsl_qspi_init_lut(struct fsl_qspi *q)
 		dummy = 8;
 	}
 
-	writel(LUT0(CMD, PAD1, cmd) | LUT1(ADDR, PAD1, addrlen),
+	qspi_writel(q, LUT0(CMD, PAD1, cmd) | LUT1(ADDR, PAD1, addrlen),
 			base + QUADSPI_LUT(lut_base));
-	writel(LUT0(DUMMY, PAD1, dummy) | LUT1(FSL_READ, PAD4, rxfifo),
+	qspi_writel(q, LUT0(DUMMY, PAD1, dummy) | LUT1(FSL_READ, PAD4, rxfifo),
 			base + QUADSPI_LUT(lut_base + 1));
 
 	/* Write enable */
 	lut_base = SEQID_WREN * 4;
-	writel(LUT0(CMD, PAD1, SPINOR_OP_WREN), base + QUADSPI_LUT(lut_base));
+	qspi_writel(q, LUT0(CMD, PAD1, SPINOR_OP_WREN),
+			base + QUADSPI_LUT(lut_base));
 
 	/* Page Program */
 	lut_base = SEQID_PP * 4;
@@ -385,13 +409,15 @@ static void fsl_qspi_init_lut(struct fsl_qspi *q)
 		addrlen = ADDR32BIT;
 	}
 
-	writel(LUT0(CMD, PAD1, cmd) | LUT1(ADDR, PAD1, addrlen),
+	qspi_writel(q, LUT0(CMD, PAD1, cmd) | LUT1(ADDR, PAD1, addrlen),
 			base + QUADSPI_LUT(lut_base));
-	writel(LUT0(FSL_WRITE, PAD1, 0), base + QUADSPI_LUT(lut_base + 1));
+	qspi_writel(q, LUT0(FSL_WRITE, PAD1, 0),
+			base + QUADSPI_LUT(lut_base + 1));
 
 	/* Read Status */
 	lut_base = SEQID_RDSR * 4;
-	writel(LUT0(CMD, PAD1, SPINOR_OP_RDSR) | LUT1(FSL_READ, PAD1, 0x1),
+	qspi_writel(q, LUT0(CMD, PAD1, SPINOR_OP_RDSR) |
+			LUT1(FSL_READ, PAD1, 0x1),
 			base + QUADSPI_LUT(lut_base));
 
 	/* Erase a sector */
@@ -400,40 +426,46 @@ static void fsl_qspi_init_lut(struct fsl_qspi *q)
 	cmd = q->nor[0].erase_opcode;
 	addrlen = q->nor_size <= SZ_16M ? ADDR24BIT : ADDR32BIT;
 
-	writel(LUT0(CMD, PAD1, cmd) | LUT1(ADDR, PAD1, addrlen),
+	qspi_writel(q, LUT0(CMD, PAD1, cmd) | LUT1(ADDR, PAD1, addrlen),
 			base + QUADSPI_LUT(lut_base));
 
 	/* Erase the whole chip */
 	lut_base = SEQID_CHIP_ERASE * 4;
-	writel(LUT0(CMD, PAD1, SPINOR_OP_CHIP_ERASE),
+	qspi_writel(q, LUT0(CMD, PAD1, SPINOR_OP_CHIP_ERASE),
 			base + QUADSPI_LUT(lut_base));
 
 	/* READ ID */
 	lut_base = SEQID_RDID * 4;
-	writel(LUT0(CMD, PAD1, SPINOR_OP_RDID) | LUT1(FSL_READ, PAD1, 0x8),
+	qspi_writel(q, LUT0(CMD, PAD1, SPINOR_OP_RDID) |
+			LUT1(FSL_READ, PAD1, 0x8),
 			base + QUADSPI_LUT(lut_base));
 
 	/* Write Register */
 	lut_base = SEQID_WRSR * 4;
-	writel(LUT0(CMD, PAD1, SPINOR_OP_WRSR) | LUT1(FSL_WRITE, PAD1, 0x2),
+	qspi_writel(q, LUT0(CMD, PAD1, SPINOR_OP_WRSR) |
+			LUT1(FSL_WRITE, PAD1, 0x2),
 			base + QUADSPI_LUT(lut_base));
 
 	/* Read Configuration Register */
 	lut_base = SEQID_RDCR * 4;
-	writel(LUT0(CMD, PAD1, SPINOR_OP_RDCR) | LUT1(FSL_READ, PAD1, 0x1),
+	qspi_writel(q, LUT0(CMD, PAD1, SPINOR_OP_RDCR) |
+			LUT1(FSL_READ, PAD1, 0x1),
 			base + QUADSPI_LUT(lut_base));
 
 	/* Write disable */
 	lut_base = SEQID_WRDI * 4;
-	writel(LUT0(CMD, PAD1, SPINOR_OP_WRDI), base + QUADSPI_LUT(lut_base));
+	qspi_writel(q, LUT0(CMD, PAD1, SPINOR_OP_WRDI),
+			base + QUADSPI_LUT(lut_base));
 
 	/* Enter 4 Byte Mode (Micron) */
 	lut_base = SEQID_EN4B * 4;
-	writel(LUT0(CMD, PAD1, SPINOR_OP_EN4B), base + QUADSPI_LUT(lut_base));
+	qspi_writel(q, LUT0(CMD, PAD1, SPINOR_OP_EN4B),
+			base + QUADSPI_LUT(lut_base));
 
 	/* Enter 4 Byte Mode (Spansion) */
 	lut_base = SEQID_BRWR * 4;
-	writel(LUT0(CMD, PAD1, SPINOR_OP_BRWR), base + QUADSPI_LUT(lut_base));
+	qspi_writel(q, LUT0(CMD, PAD1, SPINOR_OP_BRWR),
+			base + QUADSPI_LUT(lut_base));
 
 	fsl_qspi_lock_lut(q);
 }
@@ -488,15 +520,16 @@ fsl_qspi_runcmd(struct fsl_qspi *q, u8 cmd, unsigned int addr, int len)
 			q->chip_base_addr, addr, len, cmd);
 
 	/* save the reg */
-	reg = readl(base + QUADSPI_MCR);
+	reg = qspi_readl(q, base + QUADSPI_MCR);
 
-	writel(q->memmap_phy + q->chip_base_addr + addr, base + QUADSPI_SFAR);
-	writel(QUADSPI_RBCT_WMRK_MASK | QUADSPI_RBCT_RXBRD_USEIPS,
+	qspi_writel(q, q->memmap_phy + q->chip_base_addr + addr,
+			base + QUADSPI_SFAR);
+	qspi_writel(q, QUADSPI_RBCT_WMRK_MASK | QUADSPI_RBCT_RXBRD_USEIPS,
 			base + QUADSPI_RBCT);
-	writel(reg | QUADSPI_MCR_CLR_RXF_MASK, base + QUADSPI_MCR);
+	qspi_writel(q, reg | QUADSPI_MCR_CLR_RXF_MASK, base + QUADSPI_MCR);
 
 	do {
-		reg2 = readl(base + QUADSPI_SR);
+		reg2 = qspi_readl(q, base + QUADSPI_SR);
 		if (reg2 & (QUADSPI_SR_IP_ACC_MASK | QUADSPI_SR_AHB_ACC_MASK)) {
 			udelay(1);
 			dev_dbg(q->dev, "The controller is busy, 0x%x\n", reg2);
@@ -507,21 +540,22 @@ fsl_qspi_runcmd(struct fsl_qspi *q, u8 cmd, unsigned int addr, int len)
 
 	/* trigger the LUT now */
 	seqid = fsl_qspi_get_seqid(q, cmd);
-	writel((seqid << QUADSPI_IPCR_SEQID_SHIFT) | len, base + QUADSPI_IPCR);
+	qspi_writel(q, (seqid << QUADSPI_IPCR_SEQID_SHIFT) | len,
+			base + QUADSPI_IPCR);
 
 	/* Wait for the interrupt. */
 	if (!wait_for_completion_timeout(&q->c, msecs_to_jiffies(1000))) {
 		dev_err(q->dev,
 			"cmd 0x%.2x timeout, addr@%.8x, FR:0x%.8x, SR:0x%.8x\n",
-			cmd, addr, readl(base + QUADSPI_FR),
-			readl(base + QUADSPI_SR));
+			cmd, addr, qspi_readl(q, base + QUADSPI_FR),
+			qspi_readl(q, base + QUADSPI_SR));
 		err = -ETIMEDOUT;
 	} else {
 		err = 0;
 	}
 
 	/* restore the MCR */
-	writel(reg, base + QUADSPI_MCR);
+	qspi_writel(q, reg, base + QUADSPI_MCR);
 
 	return err;
 }
@@ -533,7 +567,7 @@ static void fsl_qspi_read_data(struct fsl_qspi *q, int len, u8 *rxbuf)
 	int i = 0;
 
 	while (len > 0) {
-		tmp = readl(q->iobase + QUADSPI_RBDR + i * 4);
+		tmp = qspi_readl(q, q->iobase + QUADSPI_RBDR + i * 4);
 		tmp = fsl_qspi_endian_xchg(q, tmp);
 		dev_dbg(q->dev, "chip addr:0x%.8x, rcv:0x%.8x\n",
 				q->chip_base_addr, tmp);
@@ -561,9 +595,9 @@ static inline void fsl_qspi_invalid(struct fsl_qspi *q)
 {
 	u32 reg;
 
-	reg = readl(q->iobase + QUADSPI_MCR);
+	reg = qspi_readl(q, q->iobase + QUADSPI_MCR);
 	reg |= QUADSPI_MCR_SWRSTHD_MASK | QUADSPI_MCR_SWRSTSD_MASK;
-	writel(reg, q->iobase + QUADSPI_MCR);
+	qspi_writel(q, reg, q->iobase + QUADSPI_MCR);
 
 	/*
 	 * The minimum delay : 1 AHB + 2 SFCK clocks.
@@ -572,7 +606,7 @@ static inline void fsl_qspi_invalid(struct fsl_qspi *q)
 	udelay(1);
 
 	reg &= ~(QUADSPI_MCR_SWRSTHD_MASK | QUADSPI_MCR_SWRSTSD_MASK);
-	writel(reg, q->iobase + QUADSPI_MCR);
+	qspi_writel(q, reg, q->iobase + QUADSPI_MCR);
 }
 
 static int fsl_qspi_nor_write(struct fsl_qspi *q, struct spi_nor *nor,
@@ -586,20 +620,20 @@ static int fsl_qspi_nor_write(struct fsl_qspi *q, struct spi_nor *nor,
 		q->chip_base_addr, to, count);
 
 	/* clear the TX FIFO. */
-	tmp = readl(q->iobase + QUADSPI_MCR);
-	writel(tmp | QUADSPI_MCR_CLR_TXF_MASK, q->iobase + QUADSPI_MCR);
+	tmp = qspi_readl(q, q->iobase + QUADSPI_MCR);
+	qspi_writel(q, tmp | QUADSPI_MCR_CLR_TXF_MASK, q->iobase + QUADSPI_MCR);
 
 	/* fill the TX data to the FIFO */
 	for (j = 0, i = ((count + 3) / 4); j < i; j++) {
 		tmp = fsl_qspi_endian_xchg(q, *txbuf);
-		writel(tmp, q->iobase + QUADSPI_TBDR);
+		qspi_writel(q, tmp, q->iobase + QUADSPI_TBDR);
 		txbuf++;
 	}
 
 	/* fill the TXFIFO upto 16 bytes for i.MX7d */
 	if (needs_fill_txfifo(q))
 		for (; i < 4; i++)
-			writel(tmp, q->iobase + QUADSPI_TBDR);
+			qspi_writel(q, tmp, q->iobase + QUADSPI_TBDR);
 
 	/* Trigger it */
 	ret = fsl_qspi_runcmd(q, opcode, to, count);
@@ -615,10 +649,10 @@ static void fsl_qspi_set_map_addr(struct fsl_qspi *q)
 	int nor_size = q->nor_size;
 	void __iomem *base = q->iobase;
 
-	writel(nor_size + q->memmap_phy, base + QUADSPI_SFA1AD);
-	writel(nor_size * 2 + q->memmap_phy, base + QUADSPI_SFA2AD);
-	writel(nor_size * 3 + q->memmap_phy, base + QUADSPI_SFB1AD);
-	writel(nor_size * 4 + q->memmap_phy, base + QUADSPI_SFB2AD);
+	qspi_writel(q, nor_size + q->memmap_phy, base + QUADSPI_SFA1AD);
+	qspi_writel(q, nor_size * 2 + q->memmap_phy, base + QUADSPI_SFA2AD);
+	qspi_writel(q, nor_size * 3 + q->memmap_phy, base + QUADSPI_SFB1AD);
+	qspi_writel(q, nor_size * 4 + q->memmap_phy, base + QUADSPI_SFB2AD);
 }
 
 /*
@@ -640,24 +674,26 @@ static void fsl_qspi_init_abh_read(struct fsl_qspi *q)
 	int seqid;
 
 	/* AHB configuration for access buffer 0/1/2 .*/
-	writel(QUADSPI_BUFXCR_INVALID_MSTRID, base + QUADSPI_BUF0CR);
-	writel(QUADSPI_BUFXCR_INVALID_MSTRID, base + QUADSPI_BUF1CR);
-	writel(QUADSPI_BUFXCR_INVALID_MSTRID, base + QUADSPI_BUF2CR);
+	qspi_writel(q, QUADSPI_BUFXCR_INVALID_MSTRID, base + QUADSPI_BUF0CR);
+	qspi_writel(q, QUADSPI_BUFXCR_INVALID_MSTRID, base + QUADSPI_BUF1CR);
+	qspi_writel(q, QUADSPI_BUFXCR_INVALID_MSTRID, base + QUADSPI_BUF2CR);
 	/*
 	 * Set ADATSZ with the maximum AHB buffer size to improve the
 	 * read performance.
 	 */
-	writel(QUADSPI_BUF3CR_ALLMST_MASK | ((q->devtype_data->ahb_buf_size / 8)
-			<< QUADSPI_BUF3CR_ADATSZ_SHIFT), base + QUADSPI_BUF3CR);
+	qspi_writel(q, QUADSPI_BUF3CR_ALLMST_MASK |
+			((q->devtype_data->ahb_buf_size / 8)
+			<< QUADSPI_BUF3CR_ADATSZ_SHIFT),
+			base + QUADSPI_BUF3CR);
 
 	/* We only use the buffer3 */
-	writel(0, base + QUADSPI_BUF0IND);
-	writel(0, base + QUADSPI_BUF1IND);
-	writel(0, base + QUADSPI_BUF2IND);
+	qspi_writel(q, 0, base + QUADSPI_BUF0IND);
+	qspi_writel(q, 0, base + QUADSPI_BUF1IND);
+	qspi_writel(q, 0, base + QUADSPI_BUF2IND);
 
 	/* Set the default lut sequence for AHB Read. */
 	seqid = fsl_qspi_get_seqid(q, q->nor[0].read_opcode);
-	writel(seqid << QUADSPI_BFGENCR_SEQID_SHIFT,
+	qspi_writel(q, seqid << QUADSPI_BFGENCR_SEQID_SHIFT,
 		q->iobase + QUADSPI_BFGENCR);
 }
 
@@ -713,7 +749,7 @@ static int fsl_qspi_nor_setup(struct fsl_qspi *q)
 		return ret;
 
 	/* Reset the module */
-	writel(QUADSPI_MCR_SWRSTSD_MASK | QUADSPI_MCR_SWRSTHD_MASK,
+	qspi_writel(q, QUADSPI_MCR_SWRSTSD_MASK | QUADSPI_MCR_SWRSTHD_MASK,
 		base + QUADSPI_MCR);
 	udelay(1);
 
@@ -721,24 +757,24 @@ static int fsl_qspi_nor_setup(struct fsl_qspi *q)
 	fsl_qspi_init_lut(q);
 
 	/* Disable the module */
-	writel(QUADSPI_MCR_MDIS_MASK | QUADSPI_MCR_RESERVED_MASK,
+	qspi_writel(q, QUADSPI_MCR_MDIS_MASK | QUADSPI_MCR_RESERVED_MASK,
 			base + QUADSPI_MCR);
 
-	reg = readl(base + QUADSPI_SMPR);
-	writel(reg & ~(QUADSPI_SMPR_FSDLY_MASK
+	reg = qspi_readl(q, base + QUADSPI_SMPR);
+	qspi_writel(q, reg & ~(QUADSPI_SMPR_FSDLY_MASK
 			| QUADSPI_SMPR_FSPHS_MASK
 			| QUADSPI_SMPR_HSENA_MASK
 			| QUADSPI_SMPR_DDRSMP_MASK), base + QUADSPI_SMPR);
 
 	/* Enable the module */
-	writel(QUADSPI_MCR_RESERVED_MASK | QUADSPI_MCR_END_CFG_MASK,
+	qspi_writel(q, QUADSPI_MCR_RESERVED_MASK | QUADSPI_MCR_END_CFG_MASK,
 			base + QUADSPI_MCR);
 
 	/* clear all interrupt status */
-	writel(0xffffffff, q->iobase + QUADSPI_FR);
+	qspi_writel(q, 0xffffffff, q->iobase + QUADSPI_FR);
 
 	/* enable the interrupt */
-	writel(QUADSPI_RSER_TFIE, q->iobase + QUADSPI_RSER);
+	qspi_writel(q, QUADSPI_RSER_TFIE, q->iobase + QUADSPI_RSER);
 
 	return 0;
 }
@@ -954,6 +990,7 @@ static int fsl_qspi_probe(struct platform_device *pdev)
 	if (IS_ERR(q->iobase))
 		return PTR_ERR(q->iobase);
 
+	q->big_endian = of_property_read_bool(np, "big-endian");
 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
 					"QuadSPI-memory");
 	if (!devm_request_mem_region(dev, res->start, resource_size(res),
@@ -1101,8 +1138,8 @@ static int fsl_qspi_remove(struct platform_device *pdev)
 	}
 
 	/* disable the hardware */
-	writel(QUADSPI_MCR_MDIS_MASK, q->iobase + QUADSPI_MCR);
-	writel(0x0, q->iobase + QUADSPI_RSER);
+	qspi_writel(q, QUADSPI_MCR_MDIS_MASK, q->iobase + QUADSPI_MCR);
+	qspi_writel(q, 0x0, q->iobase + QUADSPI_RSER);
 
 	mutex_destroy(&q->lock);