usb: gadget: Add UDC driver for Aeroflex Gaisler GRUSBDC

This adds an UDC driver for GRUSBDC USB Device Controller cores available in the
GRLIB VHDL IP core library. The driver only supports DMA mode.
Signed-off-by: Andreas Larsson <andreas@gaisler.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

Documentation/devicetree/bindings/usb/gr-udc.txt

+USB Peripheral Controller driver for Aeroflex Gaisler GRUSBDC.
+
+The GRUSBDC USB Device Controller core is available in the GRLIB VHDL
+IP core library.
+
+Note: In the ordinary environment for the core, a Leon SPARC system,
+these properties are built from information in the AMBA plug&play.
+
+Required properties:
+
+- name : Should be "GAISLER_USBDC" or "01_021"
+
+- reg : Address and length of the register set for the device
+
+- interrupts : Interrupt numbers for this device
+
+Optional properties:
+
+- epobufsizes : An array of buffer sizes for OUT endpoints. If the property is
+	not present, or for endpoints outside of the array, 1024 is assumed by
+	the driver.
+
+- epibufsizes : An array of buffer sizes for IN endpoints. If the property is
+	not present, or for endpoints outside of the array, 1024 is assumed by
+	the driver.
+
+For further information look in the documentation for the GLIB IP core library:
+http://www.gaisler.com/products/grlib/grip.pdf

drivers/usb/gadget/Kconfig

@@ -216,6 +216,13 @@ config USB_FOTG210_UDC
 	   Say "y" to link the driver statically, or "m" to build a
 	   dynamically linked module called "fotg210_udc".
 
+config USB_GR_UDC
+       tristate "Aeroflex Gaisler GRUSBDC USB Peripheral Controller Driver"
+       depends on HAS_DMA
+       help
+          Select this to support Aeroflex Gaisler GRUSBDC cores from the GRLIB
+	  VHDL IP core library.
+
 config USB_OMAP
 	tristate "OMAP USB Device Controller"
 	depends on ARCH_OMAP1

drivers/usb/gadget/Makefile

@@ -35,6 +35,7 @@ mv_udc-y			:= mv_udc_core.o
 obj-$(CONFIG_USB_FUSB300)	+= fusb300_udc.o
 obj-$(CONFIG_USB_FOTG210_UDC)	+= fotg210-udc.o
 obj-$(CONFIG_USB_MV_U3D)	+= mv_u3d_core.o
+obj-$(CONFIG_USB_GR_UDC)	+= gr_udc.o
 
 # USB Functions
 usb_f_acm-y			:= f_acm.o

drivers/usb/gadget/gr_udc.h

+/*
+ * USB Peripheral Controller driver for Aeroflex Gaisler GRUSBDC.
+ *
+ * 2013 (c) Aeroflex Gaisler AB
+ *
+ * This driver supports GRUSBDC USB Device Controller cores available in the
+ * GRLIB VHDL IP core library.
+ *
+ * Full documentation of the GRUSBDC core can be found here:
+ * http://www.gaisler.com/products/grlib/grip.pdf
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ * Contributors:
+ * - Andreas Larsson <andreas@gaisler.com>
+ * - Marko Isomaki
+ */
+
+/* Control registers on the AMBA bus */
+
+#define GR_MAXEP	16	/* Max # endpoints for *each* direction */
+
+struct gr_epregs {
+	u32 epctrl;
+	union {
+		struct { /* Slave mode*/
+			u32 slvctrl;
+			u32 slvdata;
+		};
+		struct { /* DMA mode*/
+			u32 dmactrl;
+			u32 dmaaddr;
+		};
+	};
+	u32 epstat;
+};
+
+struct gr_regs {
+	struct gr_epregs	epo[GR_MAXEP];	/* 0x000 - 0x0fc */
+	struct gr_epregs	epi[GR_MAXEP];	/* 0x100 - 0x1fc */
+	u32			control;	/* 0x200 */
+	u32			status;		/* 0x204 */
+};
+
+#define GR_EPCTRL_BUFSZ_SCALER	8
+#define GR_EPCTRL_BUFSZ_MASK	0xffe00000
+#define GR_EPCTRL_BUFSZ_POS	21
+#define GR_EPCTRL_PI		BIT(20)
+#define GR_EPCTRL_CB		BIT(19)
+#define GR_EPCTRL_CS		BIT(18)
+#define GR_EPCTRL_MAXPL_MASK	0x0003ff80
+#define GR_EPCTRL_MAXPL_POS	7
+#define GR_EPCTRL_NT_MASK	0x00000060
+#define GR_EPCTRL_NT_POS	5
+#define GR_EPCTRL_TT_MASK	0x00000018
+#define GR_EPCTRL_TT_POS	3
+#define GR_EPCTRL_EH		BIT(2)
+#define GR_EPCTRL_ED		BIT(1)
+#define GR_EPCTRL_EV		BIT(0)
+
+#define GR_DMACTRL_AE		BIT(10)
+#define GR_DMACTRL_AD		BIT(3)
+#define GR_DMACTRL_AI		BIT(2)
+#define GR_DMACTRL_IE		BIT(1)
+#define GR_DMACTRL_DA		BIT(0)
+
+#define GR_EPSTAT_PT		BIT(29)
+#define GR_EPSTAT_PR		BIT(29)
+#define GR_EPSTAT_B1CNT_MASK	0x1fff0000
+#define GR_EPSTAT_B1CNT_POS	16
+#define GR_EPSTAT_B0CNT_MASK	0x0000fff8
+#define GR_EPSTAT_B0CNT_POS	3
+#define GR_EPSTAT_B1		BIT(2)
+#define GR_EPSTAT_B0		BIT(1)
+#define GR_EPSTAT_BS		BIT(0)
+
+#define GR_CONTROL_SI		BIT(31)
+#define GR_CONTROL_UI		BIT(30)
+#define GR_CONTROL_VI		BIT(29)
+#define GR_CONTROL_SP		BIT(28)
+#define GR_CONTROL_FI		BIT(27)
+#define GR_CONTROL_EP		BIT(14)
+#define GR_CONTROL_DH		BIT(13)
+#define GR_CONTROL_RW		BIT(12)
+#define GR_CONTROL_TS_MASK	0x00000e00
+#define GR_CONTROL_TS_POS	9
+#define GR_CONTROL_TM		BIT(8)
+#define GR_CONTROL_UA_MASK	0x000000fe
+#define GR_CONTROL_UA_POS	1
+#define GR_CONTROL_SU		BIT(0)
+
+#define GR_STATUS_NEPI_MASK	0xf0000000
+#define GR_STATUS_NEPI_POS	28
+#define GR_STATUS_NEPO_MASK	0x0f000000
+#define GR_STATUS_NEPO_POS	24
+#define GR_STATUS_DM		BIT(23)
+#define GR_STATUS_SU		BIT(17)
+#define GR_STATUS_UR		BIT(16)
+#define GR_STATUS_VB		BIT(15)
+#define GR_STATUS_SP		BIT(14)
+#define GR_STATUS_AF_MASK	0x00003800
+#define GR_STATUS_AF_POS	11
+#define GR_STATUS_FN_MASK	0x000007ff
+#define GR_STATUS_FN_POS	0
+
+
+#define MAX_CTRL_PL_SIZE 64 /* As per USB standard for full and high speed */
+
+/*-------------------------------------------------------------------------*/
+
+/* Driver data structures and utilities */
+
+struct gr_dma_desc {
+	u32 ctrl;
+	u32 data;
+	u32 next;
+
+	/* These must be last because hw uses the previous three */
+	u32 paddr;
+	struct gr_dma_desc *next_desc;
+};
+
+#define GR_DESC_OUT_CTRL_SE		BIT(17)
+#define GR_DESC_OUT_CTRL_IE		BIT(15)
+#define GR_DESC_OUT_CTRL_NX		BIT(14)
+#define GR_DESC_OUT_CTRL_EN		BIT(13)
+#define GR_DESC_OUT_CTRL_LEN_MASK	0x00001fff
+
+#define GR_DESC_IN_CTRL_MO		BIT(18)
+#define GR_DESC_IN_CTRL_PI		BIT(17)
+#define GR_DESC_IN_CTRL_ML		BIT(16)
+#define GR_DESC_IN_CTRL_IE		BIT(15)
+#define GR_DESC_IN_CTRL_NX		BIT(14)
+#define GR_DESC_IN_CTRL_EN		BIT(13)
+#define GR_DESC_IN_CTRL_LEN_MASK	0x00001fff
+
+#define GR_DESC_DMAADDR_MASK		0xfffffffc
+
+struct gr_ep {
+	struct usb_ep ep;
+	struct gr_udc *dev;
+	u16 bytes_per_buffer;
+	unsigned int dma_start;
+	struct gr_epregs __iomem *regs;
+
+	unsigned num:8;
+	unsigned is_in:1;
+	unsigned stopped:1;
+	unsigned wedged:1;
+	unsigned callback:1;
+
+	/* analogous to a host-side qh */
+	struct list_head queue;
+
+	struct list_head ep_list;
+};
+
+struct gr_request {
+	struct usb_request req;
+	struct list_head queue;
+
+	/* Chain of dma descriptors */
+	struct gr_dma_desc *first_desc; /* First in the chain */
+	struct gr_dma_desc *curr_desc; /* Current descriptor */
+	struct gr_dma_desc *last_desc; /* Last in the chain */
+
+	u8 setup; /* Setup packet */
+};
+
+enum gr_ep0state {
+	GR_EP0_DISCONNECT = 0,	/* No host */
+	GR_EP0_SETUP,		/* Between STATUS ack and SETUP report */
+	GR_EP0_IDATA,		/* IN data stage */
+	GR_EP0_ODATA,		/* OUT data stage */
+	GR_EP0_ISTATUS,		/* Status stage after IN data stage */
+	GR_EP0_OSTATUS,		/* Status stage after OUT data stage */
+	GR_EP0_STALL,		/* Data or status stages */
+	GR_EP0_SUSPEND,		/* USB suspend */
+};
+
+struct gr_udc {
+	struct usb_gadget gadget;
+	struct gr_ep epi[GR_MAXEP];
+	struct gr_ep epo[GR_MAXEP];
+	struct usb_gadget_driver *driver;
+	struct dma_pool *desc_pool;
+	struct device *dev;
+
+	enum gr_ep0state ep0state;
+	struct gr_request *ep0reqo;
+	struct gr_request *ep0reqi;
+
+	struct gr_regs __iomem *regs;
+	int irq;
+	int irqi;
+	int irqo;
+
+	unsigned added:1;
+	unsigned irq_enabled:1;
+	unsigned remote_wakeup:1;
+
+	u8 test_mode;
+
+	enum usb_device_state suspended_from;
+
+	unsigned int nepi;
+	unsigned int nepo;
+
+	struct list_head ep_list;
+
+	spinlock_t lock; /* General lock, a.k.a. "dev->lock" in comments */
+
+	struct dentry *dfs_root;
+	struct dentry *dfs_state;
+};
+
+#define to_gr_udc(gadget)	(container_of((gadget), struct gr_udc, gadget))