[PATCH 1/3] spi: spi-nxp-fspi: dynamically alloc AHB memory for FSPI

[han . xu]

From: Han Xu <han...@nxp.com>

dynamically alloc AHB memory for FSPI controller

Signed-off-by: Han Xu <han...@nxp.com>
---
 drivers/spi/spi-nxp-fspi.c | 39 ++++++++++++++++++++++++++++++--------
 1 file changed, 31 insertions(+), 8 deletions(-)

diff --git a/drivers/spi/spi-nxp-fspi.c b/drivers/spi/spi-nxp-fspi.c
index 8894f98cc99c..84edaca28e01 100644
--- a/drivers/spi/spi-nxp-fspi.c
+++ b/drivers/spi/spi-nxp-fspi.c
@@ -307,6 +307,7 @@
 
 #define POLL_TOUT              5000
 #define NXP_FSPI_MAX_CHIPSELECT                4
+#define NXP_FSPI_MIN_IOMAP     SZ_4M
 
 struct nxp_fspi_devtype_data {
        unsigned int rxfifo;
@@ -329,6 +330,8 @@ struct nxp_fspi {
        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;
@@ -641,12 +644,34 @@ static void nxp_fspi_select_mem(struct nxp_fspi *f, 
struct spi_device *spi)
        f->selected = spi->chip_select;
 }
 
-static void nxp_fspi_read_ahb(struct nxp_fspi *f, const struct spi_mem_op *op)
+static int nxp_fspi_read_ahb(struct nxp_fspi *f, const struct spi_mem_op *op)
 {
+       u32 start = op->addr.val;
        u32 len = op->data.nbytes;
 
+       /* if necessary, ioremap before AHB read */
+       if ((!f->ahb_addr) || start < f->memmap_start ||
+           start + len > f->memmap_start + f->memmap_len) {
+               if (f->ahb_addr)
+                       iounmap(f->ahb_addr);
+
+               f->memmap_start = start;
+               f->memmap_len = len > NXP_FSPI_MIN_IOMAP ?
+                               len : NXP_FSPI_MIN_IOMAP;
+
+               f->ahb_addr = ioremap_wc(f->memmap_phy + f->memmap_start,
+                                        f->memmap_len);
+               if (!f->ahb_addr) {
+                       dev_err(f->dev, "failed to alloc memory\n");
+                       return -ENOMEM;
+               }
+       }
+
        /* Read out the data directly from the AHB buffer. */
-       memcpy_fromio(op->data.buf.in, (f->ahb_addr + op->addr.val), len);
+       memcpy_fromio(op->data.buf.in,
+                     (f->ahb_addr + start - f->memmap_start), len);
+
+       return 0;
 }
 
 static void nxp_fspi_fill_txfifo(struct nxp_fspi *f,
@@ -806,7 +831,7 @@ static int nxp_fspi_exec_op(struct spi_mem *mem, const 
struct spi_mem_op *op)
         */
        if (op->data.nbytes > (f->devtype_data->rxfifo - 4) &&
            op->data.dir == SPI_MEM_DATA_IN) {
-               nxp_fspi_read_ahb(f, op);
+               err = nxp_fspi_read_ahb(f, op);
        } else {
                if (op->data.nbytes && op->data.dir == SPI_MEM_DATA_OUT)
                        nxp_fspi_fill_txfifo(f, op);
@@ -976,11 +1001,6 @@ static int nxp_fspi_probe(struct platform_device *pdev)
 
        /* find the resources - controller memory mapped space */
        res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "fspi_mmap");
-       f->ahb_addr = devm_ioremap_resource(dev, res);
-       if (IS_ERR(f->ahb_addr)) {
-               ret = PTR_ERR(f->ahb_addr);
-               goto err_put_ctrl;
-       }
 
        /* assign memory mapped starting address and mapped size. */
        f->memmap_phy = res->start;
@@ -1059,6 +1079,9 @@ static int nxp_fspi_remove(struct platform_device *pdev)
 
        mutex_destroy(&f->lock);
 
+       if (f->ahb_addr)
+               iounmap(f->ahb_addr);
+
        return 0;
 }
 
-- 
2.17.1