openwrt/target/linux/layerscape/patches-5.4/817-spi-0001-spi-spi-fsl-qspi-dynamically-alloc-AHB-memory-for-QS.patch

From e1cf48a13626d0c42c5191dc4852f4dc271de010 Mon Sep 17 00:00:00 2001
From: Han Xu <han.xu@nxp.com>
Date: Tue, 9 Jul 2019 16:21:14 -0500
Subject: [PATCH] spi: spi-fsl-qspi: dynamically alloc AHB memory for QSPI

dynamically alloc AHB memory for QSPI controller.

Signed-off-by: Han Xu <han.xu@nxp.com>
[rebase]
Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
---
 drivers/spi/spi-fsl-qspi.c | 60 +++++++++++++++++++++++++++++++++-------------
 1 file changed, 43 insertions(+), 17 deletions(-)

--- a/drivers/spi/spi-fsl-qspi.c
+++ b/drivers/spi/spi-fsl-qspi.c
@@ -192,6 +192,8 @@
  */
 #define QUADSPI_QUIRK_USE_TDH_SETTING	BIT(5)
 
+#define QUADSPI_MIN_IOMAP		SZ_4M
+
 struct fsl_qspi_devtype_data {
 	unsigned int rxfifo;
 	unsigned int txfifo;
@@ -254,6 +256,9 @@ struct fsl_qspi {
 	void __iomem *iobase;
 	void __iomem *ahb_addr;
 	u32 memmap_phy;
+	u32 memmap_phy_size;
+	u32 memmap_start;
+	u32 memmap_len;
 	struct clk *clk, *clk_en;
 	struct device *dev;
 	struct completion c;
@@ -537,11 +542,34 @@ static void fsl_qspi_select_mem(struct f
 	fsl_qspi_invalidate(q);
 }
 
-static void fsl_qspi_read_ahb(struct fsl_qspi *q, const struct spi_mem_op *op)
+static int fsl_qspi_read_ahb(struct fsl_qspi *q, const struct spi_mem_op *op)
 {
+	u32 start = op->addr.val + q->selected * q->memmap_phy_size / 4;
+	u32 len = op->data.nbytes;
+
+	/* if necessary, ioremap before AHB read */
+	if ((!q->ahb_addr) || start < q->memmap_start ||
+	    start + len > q->memmap_start + q->memmap_len) {
+		if (q->ahb_addr) {
+			iounmap(q->ahb_addr);
+		}
+
+		q->memmap_start = start;
+		q->memmap_len = len > QUADSPI_MIN_IOMAP ?
+				len : QUADSPI_MIN_IOMAP;
+
+		q->ahb_addr = ioremap_wc(q->memmap_phy + q->memmap_start,
+					 q->memmap_len);
+		if (!q->ahb_addr) {
+			dev_err(q->dev, "failed to alloc memory\n");
+			return -ENOMEM;
+		}
+	}
+
 	memcpy_fromio(op->data.buf.in,
-		      q->ahb_addr + q->selected * q->devtype_data->ahb_buf_size,
-		      op->data.nbytes);
+		      q->ahb_addr + start - q->memmap_start, len);
+
+	return 0;
 }
 
 static void fsl_qspi_fill_txfifo(struct fsl_qspi *q,
@@ -646,7 +674,7 @@ static int fsl_qspi_exec_op(struct spi_m
 		addr_offset = q->memmap_phy;
 
 	qspi_writel(q,
-		    q->selected * q->devtype_data->ahb_buf_size + addr_offset,
+		    q->selected * q->memmap_phy_size / 4 + addr_offset,
 		    base + QUADSPI_SFAR);
 
 	qspi_writel(q, qspi_readl(q, base + QUADSPI_MCR) |
@@ -665,7 +693,7 @@ static int fsl_qspi_exec_op(struct spi_m
 	 */
 	if (op->data.nbytes > (q->devtype_data->rxfifo - 4) &&
 	    op->data.dir == SPI_MEM_DATA_IN) {
-		fsl_qspi_read_ahb(q, op);
+		err = fsl_qspi_read_ahb(q, op);
 	} else {
 		qspi_writel(q, QUADSPI_RBCT_WMRK_MASK |
 			    QUADSPI_RBCT_RXBRD_USEIPS, base + QUADSPI_RBCT);
@@ -763,16 +791,16 @@ static int fsl_qspi_default_setup(struct
 	 * In HW there can be a maximum of four chips on two buses with
 	 * two chip selects on each bus. We use four chip selects in SW
 	 * to differentiate between the four chips.
-	 * We use ahb_buf_size for each chip and set SFA1AD, SFA2AD, SFB1AD,
-	 * SFB2AD accordingly.
+	 * We divide the total memory region size equally for each chip
+	 * and set SFA1AD, SFA2AD, SFB1AD, SFB2AD accordingly.
 	 */
-	qspi_writel(q, q->devtype_data->ahb_buf_size + addr_offset,
+	qspi_writel(q, q->memmap_phy_size / 4 + addr_offset,
 		    base + QUADSPI_SFA1AD);
-	qspi_writel(q, q->devtype_data->ahb_buf_size * 2 + addr_offset,
+	qspi_writel(q, q->memmap_phy_size / 4 * 2 + addr_offset,
 		    base + QUADSPI_SFA2AD);
-	qspi_writel(q, q->devtype_data->ahb_buf_size * 3 + addr_offset,
+	qspi_writel(q, q->memmap_phy_size / 4 * 3 + addr_offset,
 		    base + QUADSPI_SFB1AD);
-	qspi_writel(q, q->devtype_data->ahb_buf_size * 4 + addr_offset,
+	qspi_writel(q, q->memmap_phy_size / 4 * 4 + addr_offset,
 		    base + QUADSPI_SFB2AD);
 
 	q->selected = -1;
@@ -859,13 +887,8 @@ static int fsl_qspi_probe(struct platfor
 
 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
 					"QuadSPI-memory");
-	q->ahb_addr = devm_ioremap_resource(dev, res);
-	if (IS_ERR(q->ahb_addr)) {
-		ret = PTR_ERR(q->ahb_addr);
-		goto err_put_ctrl;
-	}
-
 	q->memmap_phy = res->start;
+	q->memmap_phy_size = resource_size(res);
 
 	/* find the clocks */
 	q->clk_en = devm_clk_get(dev, "qspi_en");
@@ -939,6 +962,9 @@ static int fsl_qspi_remove(struct platfo
 
 	mutex_destroy(&q->lock);
 
+	if (q->ahb_addr)
+		iounmap(q->ahb_addr);
+
 	return 0;
 }