RE: [PATCH v5 3/9] spi: Add a driver for the Freescale/NXP QuadSPI controller

[Yogesh Narayan Gaur <yogeshnarayan.gaur@nxp.com>]

Hi Frieder,

> -----Original Message-----
> From: Schrempf Frieder [mailto:frieder.schrempf@kontron.De]
> Sent: Thursday, November 15, 2018 7:32 PM
> To: Yogesh Narayan Gaur <yogeshnarayan.gaur@nxp.com>
> Cc: Boris Brezillon <boris.brezillon@bootlin.com>; linux-mtd@lists.infradead.org;
> linux-spi@vger.kernel.org; Marek Vasut <marek.vasut@gmail.com>; Mark
> Brown <broonie@kernel.org>; Han Xu <han.xu@nxp.com>;
> dwmw2@infradead.org; computersforpeace@gmail.com; richard@nod.at;
> miquel.raynal@bootlin.com; David Wolfe <david.wolfe@nxp.com>; Fabio
> Estevam <fabio.estevam@nxp.com>; Prabhakar Kushwaha
> <prabhakar.kushwaha@nxp.com>; shawnguo@kernel.org; linux-
> kernel@vger.kernel.org
> Subject: Re: [PATCH v5 3/9] spi: Add a driver for the Freescale/NXP QuadSPI
> controller
> 
> Hi Yogesh,
> 
> On 15.11.18 14:12, Boris Brezillon wrote:
> > On Thu, 15 Nov 2018 11:43:05 +0000
> > Schrempf Frieder <frieder.schrempf@kontron.De> wrote:
> >
> >> On 15.11.18 07:22, Yogesh Narayan Gaur wrote:
> >>> Hi Frieder,
> >>>
> >>> With below patch on top of your v5, Read/Write/Erase on CS1 is working
> fine for me.
> >>
> >> Ok, are you sure, that AHB read is working too with this patch?
> >> You are removing the memmap_phy offset from SFAR and the SFXXAD
> >> register values.
> >>
> >> I can understand that selection of the CS and IP commands will work
> >> like this, but I can't understand how AHB read should work without
> >> the base address of the mapped memory.
> >>
> >> I'm afraid I still don't fully understand the background of these
> >> things,
> >
> > Same here. Yogesh, can you give us more detail on why you decided to
> > drop the memmap_phy offset?
> 
> Your changes do not work on my setup (i.MX6UL). It looks like your hardware is
> different.
> 
> I found this patch for LS2080A: [1]. This would explain why you need to remove
> the offset to make it work.
> 
> To verify this, could you please test your setup with the current spi-nor driver
> (fsl_quadspi.c). If our assumptions are right, it should only work on CS0 and CS1
> with [1] applied.
> 

Yes, I need to remove the offset to make it work and this is required for the NXP Layerscape-2.x SoCs like LS208x/Ls108x etc.

I have modified the patch and have introduced entry in quirks for ls2080a. With this Read/Write/Erase are working for me for both CS.

diff --git a/drivers/spi/spi-fsl-qspi.c b/drivers/spi/spi-fsl-qspi.c
index ce45e8e..5d26f73 100644
--- a/drivers/spi/spi-fsl-qspi.c
+++ b/drivers/spi/spi-fsl-qspi.c
@@ -175,6 +175,9 @@
 /* TKT245618, the controller cannot wake up from wait mode */
 #define QUADSPI_QUIRK_TKT245618                BIT(3)

+/* QSPI_AMBA_BASE is internally added by SOC design for LS-2.x architecture */
+#define QUADSPI_AMBA_BASE_INTERNAL     BIT(4)
+
 struct fsl_qspi_devtype_data {
        unsigned int rxfifo;
        unsigned int txfifo;
@@ -227,7 +230,7 @@ static const struct fsl_qspi_devtype_data ls2080a_data = {
        .rxfifo = SZ_128,
        .txfifo = SZ_64,
        .ahb_buf_size = SZ_1K,
-       .quirks = QUADSPI_QUIRK_TKT253890,
+       .quirks = QUADSPI_QUIRK_TKT253890 | QUADSPI_AMBA_BASE_INTERNAL,
        .little_endian = true,
 };

@@ -235,6 +238,7 @@ struct fsl_qspi {
        void __iomem *iobase;
        void __iomem *ahb_addr;
        u32 memmap_phy;
+       u32 amba_base_addr;
        struct clk *clk, *clk_en;
        struct device *dev;
        struct completion c;
@@ -264,6 +268,11 @@ static inline int needs_wakeup_wait_mode(struct fsl_qspi *q)
        return q->devtype_data->quirks & QUADSPI_QUIRK_TKT245618;
 }

+static inline int has_added_amba_base_internal(struct fsl_qspi *q)
+{
+       return q->devtype_data->quirks & QUADSPI_AMBA_BASE_INTERNAL;
+}
+
 /*
  * An IC bug makes it necessary to rearrange the 32-bit data.
  * Later chips, such as IMX6SLX, have fixed this bug.
@@ -489,29 +498,11 @@ static void fsl_qspi_invalidate(struct fsl_qspi *q)
 static void fsl_qspi_select_mem(struct fsl_qspi *q, struct spi_device *spi)
 {
        unsigned long rate = spi->max_speed_hz;
-       int ret, i;
-       u32 map_addr;
+       int ret;

        if (q->selected == spi->chip_select)
                return;

-       /*
-        * 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 the SFA1AD, SFA2AD, SFB1AD, SFB2AD registers to select
-        * the chip we want to access.
-        */
-       for (i = 0; i < 4; i++) {
-               if (i < spi->chip_select)
-                       map_addr = q->memmap_phy;
-               else
-                       map_addr = q->memmap_phy +
-                                  2 * q->devtype_data->ahb_buf_size;
-
-               qspi_writel(q, map_addr, q->iobase + QUADSPI_SFA1AD + (i * 4));
-       }
-
        if (needs_4x_clock(q))
                rate *= 4;

@@ -534,7 +525,9 @@ static void fsl_qspi_select_mem(struct fsl_qspi *q, struct spi_device *spi)

 static void fsl_qspi_read_ahb(struct fsl_qspi *q, const struct spi_mem_op *op)
 {
-       memcpy_fromio(op->data.buf.in, q->ahb_addr, op->data.nbytes);
+       memcpy_fromio(op->data.buf.in,
+                     q->ahb_addr + q->selected * q->devtype_data->ahb_buf_size,
+                     op->data.nbytes);
 }

 static void fsl_qspi_fill_txfifo(struct fsl_qspi *q,
@@ -634,7 +627,9 @@ static int fsl_qspi_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)

        fsl_qspi_select_mem(q, mem->spi);

-       qspi_writel(q, q->memmap_phy, base + QUADSPI_SFAR);
+       qspi_writel(q, q->amba_base_addr +
+                   q->selected * q->devtype_data->ahb_buf_size,
+                   base + QUADSPI_SFAR);

        qspi_writel(q, qspi_readl(q, base + QUADSPI_MCR) |
                    QUADSPI_MCR_CLR_RXF_MASK | QUADSPI_MCR_CLR_TXF_MASK,
@@ -733,6 +728,23 @@ static int fsl_qspi_default_setup(struct fsl_qspi *q)
                    QUADSPI_BUF3CR_ADATSZ(q->devtype_data->ahb_buf_size / 8),
                    base + QUADSPI_BUF3CR);

+       /*
+        * 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 the SFA1AD, SFA2AD, SFB1AD, SFB2AD registers to select
+        * the chip we want to access.
+        */
+
+       qspi_writel(q, q->amba_base_addr + q->devtype_data->ahb_buf_size,
+                   base + QUADSPI_SFA1AD);
+       qspi_writel(q, q->amba_base_addr + q->devtype_data->ahb_buf_size * 2,
+                   base + QUADSPI_SFA2AD);
+       qspi_writel(q, q->amba_base_addr + q->devtype_data->ahb_buf_size * 3,
+                   base + QUADSPI_SFB1AD);
+       qspi_writel(q, q->amba_base_addr + q->devtype_data->ahb_buf_size * 4,
+                   base + QUADSPI_SFB2AD);
+
        q->selected = -1;

        /* Enable the module */
@@ -825,6 +837,11 @@ static int fsl_qspi_probe(struct platform_device *pdev)

        q->memmap_phy = res->start;

+       if (has_added_amba_base_internal(q))
+               q->amba_base_addr = 0;
+       else
+               q->amba_base_addr = q->memmap_phy;
+
        /* find the clocks */
        q->clk_en = devm_clk_get(dev, "qspi_en");
        if (IS_ERR(q->clk_en)) {

--
Regards
Yogesh Gaur
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