usb: gadget: udc: atmel: Update endpoint allocation scheme

This patch updates the usb endpoint allocation scheme for atmel usba
driver to make sure all endpoints are allocated in order. This
requirement comes from the datasheet of the controller.

The allocation scheme is decided by fifo_mode parameter. For fifo_mode =
0 the driver tries to autoconfigure the endpoints fifo size. All other
modes contain fixed configurations optimized for different purposes. The
idea is somehow similar with the approach used on musb driver.
Signed-off-by: Cristian Birsan <cristian.birsan@microchip.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/gadget/udc/Kconfig

@@ -60,6 +60,20 @@ config USB_ATMEL_USBA
 	  USBA is the integrated high-speed USB Device controller on
 	  the AT32AP700x, some AT91SAM9 and AT91CAP9 processors from Atmel.
 
+	  The fifo_mode parameter is used to select endpoint allocation mode.
+	  fifo_mode = 0 is used to let the driver autoconfigure the endpoints.
+	  In this case 2 banks are allocated for isochronous endpoints and
+	  only one bank is allocated for the rest of the endpoints.
+
+	  fifo_mode = 1 is a generic maximum fifo size (1024 bytes) configuration
+	  allowing the usage of ep1 - ep6
+
+	  fifo_mode = 2 is a generic performance maximum fifo size (1024 bytes)
+	  configuration allowing the usage of ep1 - ep3
+
+	  fifo_mode = 3 is a balanced performance configuration allowing the
+	  the usage of ep1 - ep8
+
 config USB_BCM63XX_UDC
 	tristate "Broadcom BCM63xx Peripheral Controller"
 	depends on BCM63XX

drivers/usb/gadget/udc/atmel_usba_udc.h

@@ -275,6 +275,12 @@ struct usba_dma_desc {
 	u32 ctrl;
 };
 
+struct usba_fifo_cfg {
+	u8			hw_ep_num;
+	u16			fifo_size;
+	u8			nr_banks;
+};
+
 struct usba_ep {
 	int					state;
 	void __iomem				*ep_regs;
@@ -292,7 +298,7 @@ struct usba_ep {
 	unsigned int				can_isoc:1;
 	unsigned int				is_isoc:1;
 	unsigned int				is_in:1;
-
+	unsigned long				ept_cfg;
 #ifdef CONFIG_USB_GADGET_DEBUG_FS
 	u32					last_dma_status;
 	struct dentry				*debugfs_dir;
@@ -337,6 +343,8 @@ struct usba_udc {
 	int vbus_pin;
 	int vbus_pin_inverted;
 	int num_ep;
+	int configured_ep;
+	struct usba_fifo_cfg *fifo_cfg;
 	struct clk *pclk;
 	struct clk *hclk;
 	struct usba_ep *usba_ep;