This patch updates the driver to support 64-bit DMA
addressing.
Signed-off-by: Nava kishore Manne <[email protected]>
---
Changes for v2:
-Added dma-ranges property in device tree as suggested by Arnd Bergmann.
-Modified the driver code based on the xlnx,addrwidth.
.../devicetree/bindings/usb/udc-xilinx.txt | 5 ++-
drivers/usb/gadget/udc/udc-xilinx.c | 39 ++++++++++++++++++++--
2 files changed, 40 insertions(+), 4 deletions(-)
diff --git a/Documentation/devicetree/bindings/usb/udc-xilinx.txt b/Documentation/devicetree/bindings/usb/udc-xilinx.txt
index 47b4e39..850d792 100644
--- a/Documentation/devicetree/bindings/usb/udc-xilinx.txt
+++ b/Documentation/devicetree/bindings/usb/udc-xilinx.txt
@@ -7,12 +7,15 @@ Required properties:
- interrupts : Should contain single irq line of USB2 device
controller
- xlnx,has-builtin-dma : if DMA is included
-
+- dma-ranges: Should be as the following <dma_addr cpu_addr max_len>.
+- xlnx,addrwidth : Should be the dma addressing size in bits(ex: 40 bits).
Example:
axi-usb2-device@42e00000 {
compatible = "xlnx,usb2-device-4.00.a";
interrupts = <0x0 0x39 0x1>;
reg = <0x42e00000 0x10000>;
+ dma-ranges = <0x00000000 0x00000000 0x40000000>;
xlnx,has-builtin-dma;
+ xlnx,addrwidth = <0x28>;
};
diff --git a/drivers/usb/gadget/udc/udc-xilinx.c b/drivers/usb/gadget/udc/udc-xilinx.c
index 1cbb0ac..702ab9e 100644
--- a/drivers/usb/gadget/udc/udc-xilinx.c
+++ b/drivers/usb/gadget/udc/udc-xilinx.c
@@ -28,6 +28,7 @@
#include <linux/of_irq.h>
#include <linux/prefetch.h>
#include <linux/usb/ch9.h>
+#include <linux/io-64-nonatomic-lo-hi.h>
#include <linux/usb/gadget.h>
/* Register offsets for the USB device.*/
@@ -47,6 +48,15 @@
#define XUSB_DMA_LENGTH_OFFSET 0x0210 /* DMA Length Register */
#define XUSB_DMA_STATUS_OFFSET 0x0214 /* DMA Status Register */
+/* DMA source Address Reg for LSB */
+#define XUSB_DMA_DSAR_ADDR_OFFSET_LSB 0x0308
+/* DMA source Address Reg for MSB */
+#define XUSB_DMA_DSAR_ADDR_OFFSET_MSB 0x030C
+/* DMA destination Addr Reg LSB */
+#define XUSB_DMA_DDAR_ADDR_OFFSET_LSB 0x0310
+/* DMA destination Addr Reg MSB */
+#define XUSB_DMA_DDAR_ADDR_OFFSET_MSB 0x0314
+
/* Endpoint Configuration Space offsets */
#define XUSB_EP_CFGSTATUS_OFFSET 0x00 /* Endpoint Config Status */
#define XUSB_EP_BUF0COUNT_OFFSET 0x08 /* Buffer 0 Count */
@@ -176,6 +186,7 @@ struct xusb_ep {
* @addr: the usb device base address
* @lock: instance of spinlock
* @dma_enabled: flag indicating whether the dma is included in the system
+ * @dma_addrwidth:Indicate the DMA address width.
* @read_fn: function pointer to read device registers
* @write_fn: function pointer to write to device registers
*/
@@ -193,7 +204,7 @@ struct xusb_udc {
void __iomem *addr;
spinlock_t lock;
bool dma_enabled;
-
+ u32 dma_addrwidth;
unsigned int (*read_fn)(void __iomem *);
void (*write_fn)(void __iomem *, u32, u32);
};
@@ -215,6 +226,17 @@ static const struct usb_endpoint_descriptor config_bulk_out_desc = {
};
/**
+ * xudc_write64 - write 64bit value to device registers
+ * @addr: base addr of device registers
+ * @offset: register offset
+ * @val: data to be written
+ **/
+static void xudc_write64(void __iomem *addr, u32 offset, u64 val)
+{
+ lo_hi_writeq(val, addr + offset);
+}
+
+/**
* xudc_write32 - little endian write to device registers
* @addr: base addr of device registers
* @offset: register offset
@@ -330,8 +352,13 @@ static int xudc_start_dma(struct xusb_ep *ep, dma_addr_t src,
* destination registers and then set the length
* into the DMA length register.
*/
- udc->write_fn(udc->addr, XUSB_DMA_DSAR_ADDR_OFFSET, src);
- udc->write_fn(udc->addr, XUSB_DMA_DDAR_ADDR_OFFSET, dst);
+ if (udc->dma_addrwidth > 32) {
+ xudc_write64(udc->addr, XUSB_DMA_DSAR_ADDR_OFFSET_LSB, src);
+ xudc_write64(udc->addr, XUSB_DMA_DDAR_ADDR_OFFSET_LSB, dst);
+ } else {
+ udc->write_fn(udc->addr, XUSB_DMA_DSAR_ADDR_OFFSET, src);
+ udc->write_fn(udc->addr, XUSB_DMA_DDAR_ADDR_OFFSET, dst);
+ }
udc->write_fn(udc->addr, XUSB_DMA_LENGTH_OFFSET, length);
/*
@@ -2097,6 +2124,12 @@ static int xudc_probe(struct platform_device *pdev)
udc->dma_enabled = of_property_read_bool(np, "xlnx,has-builtin-dma");
+ ret = of_property_read_u32(np, "xlnx,addrwidth", &udc->dma_addrwidth);
+ if (ret < 0)
+ dev_warn(&pdev->dev, "missing xlnx,addrwidth property\n");
+
+ /* Set the dma mask bits */
+ dma_set_mask(&pdev->dev, DMA_BIT_MASK(udc->dma_addrwidth));
/* Setup gadget structure */
udc->gadget.ops = &xusb_udc_ops;
udc->gadget.max_speed = USB_SPEED_HIGH;
--
2.1.2
On Tuesday 19 April 2016 16:40:48 Nava kishore Manne wrote:
> This patch updates the driver to support 64-bit DMA
> addressing.
>
> Signed-off-by: Nava kishore Manne <[email protected]>
> ---
> Changes for v2:
> -Added dma-ranges property in device tree as suggested by Arnd Bergmann.
> -Modified the driver code based on the xlnx,addrwidth.
> .../devicetree/bindings/usb/udc-xilinx.txt | 5 ++-
> drivers/usb/gadget/udc/udc-xilinx.c | 39 ++++++++++++++++++++--
> 2 files changed, 40 insertions(+), 4 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/usb/udc-xilinx.txt b/Documentation/devicetree/bindings/usb/udc-xilinx.txt
> index 47b4e39..850d792 100644
> --- a/Documentation/devicetree/bindings/usb/udc-xilinx.txt
> +++ b/Documentation/devicetree/bindings/usb/udc-xilinx.txt
> @@ -7,12 +7,15 @@ Required properties:
> - interrupts : Should contain single irq line of USB2 device
> controller
> - xlnx,has-builtin-dma : if DMA is included
> -
> +- dma-ranges: Should be as the following <dma_addr cpu_addr max_len>.
This is not how dma-ranges is works. First of all, it is part of
the parent node, and the addresses are not "dma" and "cpu"
addresses but child and parent bus addresses.
> +- xlnx,addrwidth : Should be the dma addressing size in bits(ex: 40 bits).
As I said before, the width is not the interesting question here,
the compatible string is. My guess is that version 4.00.a of the
hardware always has the registers to do 64-bit DMA, but you should
talk to the hardware designers to figure out which versions have
those, or if they are optional, and what other width may be supported.
> + * xudc_write64 - write 64bit value to device registers
> + * @addr: base addr of device registers
> + * @offset: register offset
> + * @val: data to be written
> + **/
> +static void xudc_write64(void __iomem *addr, u32 offset, u64 val)
> +{
> + lo_hi_writeq(val, addr + offset);
> +}
This is what I suggested, but on second thought I think it's still
wrong:
> * xudc_write32 - little endian write to device registers
> * @addr: base addr of device registers
> * @offset: register offset
> @@ -330,8 +352,13 @@ static int xudc_start_dma(struct xusb_ep *ep, dma_addr_t src,
> * destination registers and then set the length
> * into the DMA length register.
> */
> - udc->write_fn(udc->addr, XUSB_DMA_DSAR_ADDR_OFFSET, src);
> - udc->write_fn(udc->addr, XUSB_DMA_DDAR_ADDR_OFFSET, dst);
> + if (udc->dma_addrwidth > 32) {
> + xudc_write64(udc->addr, XUSB_DMA_DSAR_ADDR_OFFSET_LSB, src);
> + xudc_write64(udc->addr, XUSB_DMA_DDAR_ADDR_OFFSET_LSB, dst);
> + } else {
> + udc->write_fn(udc->addr, XUSB_DMA_DSAR_ADDR_OFFSET, src);
> + udc->write_fn(udc->addr, XUSB_DMA_DDAR_ADDR_OFFSET, dst);
> + }
I just noticed that write_fn() needs to be used to get the
correct endianess. lo_hi_writeq() always assumes a little-endian
register, so it's broken if anyone builds this device with big-endian
registers.
> @@ -2097,6 +2124,12 @@ static int xudc_probe(struct platform_device *pdev)
>
> udc->dma_enabled = of_property_read_bool(np, "xlnx,has-builtin-dma");
>
> + ret = of_property_read_u32(np, "xlnx,addrwidth", &udc->dma_addrwidth);
> + if (ret < 0)
> + dev_warn(&pdev->dev, "missing xlnx,addrwidth property\n");
> +
> + /* Set the dma mask bits */
> + dma_set_mask(&pdev->dev, DMA_BIT_MASK(udc->dma_addrwidth));
You have to check the return code of dma_set_mask. As I said earlier, it's
possible that someone uses a device that has the 64-bit registers on a
machine that has a 32-bit bus but more than 4GB of RAM. In this case,
dma_set_mask() will fail, and you should probably fall back to the
original method for programming the DMA address then.
Arnd