1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Xilinx USB peripheral controller driver
4  *
5  * Copyright (C) 2004 by Thomas Rathbone
6  * Copyright (C) 2005 by HP Labs
7  * Copyright (C) 2005 by David Brownell
8  * Copyright (C) 2010 - 2014 Xilinx, Inc.
9  *
10  * Some parts of this driver code is based on the driver for at91-series
11  * USB peripheral controller (at91_udc.c).
12  */
13 
14 #include <linux/clk.h>
15 #include <linux/delay.h>
16 #include <linux/device.h>
17 #include <linux/dma-mapping.h>
18 #include <linux/interrupt.h>
19 #include <linux/io.h>
20 #include <linux/module.h>
21 #include <linux/of_address.h>
22 #include <linux/of_device.h>
23 #include <linux/of_platform.h>
24 #include <linux/of_irq.h>
25 #include <linux/prefetch.h>
26 #include <linux/usb/ch9.h>
27 #include <linux/usb/gadget.h>
28 
29 /* Register offsets for the USB device.*/
30 #define XUSB_EP0_CONFIG_OFFSET		0x0000  /* EP0 Config Reg Offset */
31 #define XUSB_SETUP_PKT_ADDR_OFFSET	0x0080  /* Setup Packet Address */
32 #define XUSB_ADDRESS_OFFSET		0x0100  /* Address Register */
33 #define XUSB_CONTROL_OFFSET		0x0104  /* Control Register */
34 #define XUSB_STATUS_OFFSET		0x0108  /* Status Register */
35 #define XUSB_FRAMENUM_OFFSET		0x010C	/* Frame Number Register */
36 #define XUSB_IER_OFFSET			0x0110	/* Interrupt Enable Register */
37 #define XUSB_BUFFREADY_OFFSET		0x0114	/* Buffer Ready Register */
38 #define XUSB_TESTMODE_OFFSET		0x0118	/* Test Mode Register */
39 #define XUSB_DMA_RESET_OFFSET		0x0200  /* DMA Soft Reset Register */
40 #define XUSB_DMA_CONTROL_OFFSET		0x0204	/* DMA Control Register */
41 #define XUSB_DMA_DSAR_ADDR_OFFSET	0x0208	/* DMA source Address Reg */
42 #define XUSB_DMA_DDAR_ADDR_OFFSET	0x020C	/* DMA destination Addr Reg */
43 #define XUSB_DMA_LENGTH_OFFSET		0x0210	/* DMA Length Register */
44 #define XUSB_DMA_STATUS_OFFSET		0x0214	/* DMA Status Register */
45 
46 /* Endpoint Configuration Space offsets */
47 #define XUSB_EP_CFGSTATUS_OFFSET	0x00	/* Endpoint Config Status  */
48 #define XUSB_EP_BUF0COUNT_OFFSET	0x08	/* Buffer 0 Count */
49 #define XUSB_EP_BUF1COUNT_OFFSET	0x0C	/* Buffer 1 Count */
50 
51 #define XUSB_CONTROL_USB_READY_MASK	0x80000000 /* USB ready Mask */
52 #define XUSB_CONTROL_USB_RMTWAKE_MASK	0x40000000 /* Remote wake up mask */
53 
54 /* Interrupt register related masks.*/
55 #define XUSB_STATUS_GLOBAL_INTR_MASK	0x80000000 /* Global Intr Enable */
56 #define XUSB_STATUS_DMADONE_MASK	0x04000000 /* DMA done Mask */
57 #define XUSB_STATUS_DMAERR_MASK		0x02000000 /* DMA Error Mask */
58 #define XUSB_STATUS_DMABUSY_MASK	0x80000000 /* DMA Error Mask */
59 #define XUSB_STATUS_RESUME_MASK		0x01000000 /* USB Resume Mask */
60 #define XUSB_STATUS_RESET_MASK		0x00800000 /* USB Reset Mask */
61 #define XUSB_STATUS_SUSPEND_MASK	0x00400000 /* USB Suspend Mask */
62 #define XUSB_STATUS_DISCONNECT_MASK	0x00200000 /* USB Disconnect Mask */
63 #define XUSB_STATUS_FIFO_BUFF_RDY_MASK	0x00100000 /* FIFO Buff Ready Mask */
64 #define XUSB_STATUS_FIFO_BUFF_FREE_MASK	0x00080000 /* FIFO Buff Free Mask */
65 #define XUSB_STATUS_SETUP_PACKET_MASK	0x00040000 /* Setup packet received */
66 #define XUSB_STATUS_EP1_BUFF2_COMP_MASK	0x00000200 /* EP 1 Buff 2 Processed */
67 #define XUSB_STATUS_EP1_BUFF1_COMP_MASK	0x00000002 /* EP 1 Buff 1 Processed */
68 #define XUSB_STATUS_EP0_BUFF2_COMP_MASK	0x00000100 /* EP 0 Buff 2 Processed */
69 #define XUSB_STATUS_EP0_BUFF1_COMP_MASK	0x00000001 /* EP 0 Buff 1 Processed */
70 #define XUSB_STATUS_HIGH_SPEED_MASK	0x00010000 /* USB Speed Mask */
71 /* Suspend,Reset,Suspend and Disconnect Mask */
72 #define XUSB_STATUS_INTR_EVENT_MASK	0x01E00000
73 /* Buffers  completion Mask */
74 #define XUSB_STATUS_INTR_BUFF_COMP_ALL_MASK	0x0000FEFF
75 /* Mask for buffer 0 and buffer 1 completion for all Endpoints */
76 #define XUSB_STATUS_INTR_BUFF_COMP_SHIFT_MASK	0x00000101
77 #define XUSB_STATUS_EP_BUFF2_SHIFT	8	   /* EP buffer offset */
78 
79 /* Endpoint Configuration Status Register */
80 #define XUSB_EP_CFG_VALID_MASK		0x80000000 /* Endpoint Valid bit */
81 #define XUSB_EP_CFG_STALL_MASK		0x40000000 /* Endpoint Stall bit */
82 #define XUSB_EP_CFG_DATA_TOGGLE_MASK	0x08000000 /* Endpoint Data toggle */
83 
84 /* USB device specific global configuration constants.*/
85 #define XUSB_MAX_ENDPOINTS		8	/* Maximum End Points */
86 #define XUSB_EP_NUMBER_ZERO		0	/* End point Zero */
87 /* DPRAM is the source address for DMA transfer */
88 #define XUSB_DMA_READ_FROM_DPRAM	0x80000000
89 #define XUSB_DMA_DMASR_BUSY		0x80000000 /* DMA busy */
90 #define XUSB_DMA_DMASR_ERROR		0x40000000 /* DMA Error */
91 /*
92  * When this bit is set, the DMA buffer ready bit is set by hardware upon
93  * DMA transfer completion.
94  */
95 #define XUSB_DMA_BRR_CTRL		0x40000000 /* DMA bufready ctrl bit */
96 /* Phase States */
97 #define SETUP_PHASE			0x0000	/* Setup Phase */
98 #define DATA_PHASE			0x0001  /* Data Phase */
99 #define STATUS_PHASE			0x0002  /* Status Phase */
100 
101 #define EP0_MAX_PACKET		64 /* Endpoint 0 maximum packet length */
102 #define STATUSBUFF_SIZE		2  /* Buffer size for GET_STATUS command */
103 #define EPNAME_SIZE		4  /* Buffer size for endpoint name */
104 
105 /* container_of helper macros */
106 #define to_udc(g)	 container_of((g), struct xusb_udc, gadget)
107 #define to_xusb_ep(ep)	 container_of((ep), struct xusb_ep, ep_usb)
108 #define to_xusb_req(req) container_of((req), struct xusb_req, usb_req)
109 
110 /**
111  * struct xusb_req - Xilinx USB device request structure
112  * @usb_req: Linux usb request structure
113  * @queue: usb device request queue
114  * @ep: pointer to xusb_endpoint structure
115  */
116 struct xusb_req {
117 	struct usb_request usb_req;
118 	struct list_head queue;
119 	struct xusb_ep *ep;
120 };
121 
122 /**
123  * struct xusb_ep - USB end point structure.
124  * @ep_usb: usb endpoint instance
125  * @queue: endpoint message queue
126  * @udc: xilinx usb peripheral driver instance pointer
127  * @desc: pointer to the usb endpoint descriptor
128  * @rambase: the endpoint buffer address
129  * @offset: the endpoint register offset value
130  * @name: name of the endpoint
131  * @epnumber: endpoint number
132  * @maxpacket: maximum packet size the endpoint can store
133  * @buffer0count: the size of the packet recieved in the first buffer
134  * @buffer1count: the size of the packet received in the second buffer
135  * @curbufnum: current buffer of endpoint that will be processed next
136  * @buffer0ready: the busy state of first buffer
137  * @buffer1ready: the busy state of second buffer
138  * @is_in: endpoint direction (IN or OUT)
139  * @is_iso: endpoint type(isochronous or non isochronous)
140  */
141 struct xusb_ep {
142 	struct usb_ep ep_usb;
143 	struct list_head queue;
144 	struct xusb_udc *udc;
145 	const struct usb_endpoint_descriptor *desc;
146 	u32  rambase;
147 	u32  offset;
148 	char name[4];
149 	u16  epnumber;
150 	u16  maxpacket;
151 	u16  buffer0count;
152 	u16  buffer1count;
153 	u8   curbufnum;
154 	bool buffer0ready;
155 	bool buffer1ready;
156 	bool is_in;
157 	bool is_iso;
158 };
159 
160 /**
161  * struct xusb_udc -  USB peripheral driver structure
162  * @gadget: USB gadget driver instance
163  * @ep: an array of endpoint structures
164  * @driver: pointer to the usb gadget driver instance
165  * @setup: usb_ctrlrequest structure for control requests
166  * @req: pointer to dummy request for get status command
167  * @dev: pointer to device structure in gadget
168  * @usb_state: device in suspended state or not
169  * @remote_wkp: remote wakeup enabled by host
170  * @setupseqtx: tx status
171  * @setupseqrx: rx status
172  * @addr: the usb device base address
173  * @lock: instance of spinlock
174  * @dma_enabled: flag indicating whether the dma is included in the system
175  * @clk: pointer to struct clk
176  * @read_fn: function pointer to read device registers
177  * @write_fn: function pointer to write to device registers
178  */
179 struct xusb_udc {
180 	struct usb_gadget gadget;
181 	struct xusb_ep ep[8];
182 	struct usb_gadget_driver *driver;
183 	struct usb_ctrlrequest setup;
184 	struct xusb_req *req;
185 	struct device *dev;
186 	u32 usb_state;
187 	u32 remote_wkp;
188 	u32 setupseqtx;
189 	u32 setupseqrx;
190 	void __iomem *addr;
191 	spinlock_t lock;
192 	bool dma_enabled;
193 	struct clk *clk;
194 
195 	unsigned int (*read_fn)(void __iomem *reg);
196 	void (*write_fn)(void __iomem *, u32, u32);
197 };
198 
199 /* Endpoint buffer start addresses in the core */
200 static u32 rambase[8] = { 0x22, 0x1000, 0x1100, 0x1200, 0x1300, 0x1400, 0x1500,
201 			  0x1600 };
202 
203 static const char driver_name[] = "xilinx-udc";
204 static const char ep0name[] = "ep0";
205 
206 /* Control endpoint configuration.*/
207 static const struct usb_endpoint_descriptor config_bulk_out_desc = {
208 	.bLength		= USB_DT_ENDPOINT_SIZE,
209 	.bDescriptorType	= USB_DT_ENDPOINT,
210 	.bEndpointAddress	= USB_DIR_OUT,
211 	.bmAttributes		= USB_ENDPOINT_XFER_BULK,
212 	.wMaxPacketSize		= cpu_to_le16(EP0_MAX_PACKET),
213 };
214 
215 /**
216  * xudc_write32 - little endian write to device registers
217  * @addr: base addr of device registers
218  * @offset: register offset
219  * @val: data to be written
220  */
221 static void xudc_write32(void __iomem *addr, u32 offset, u32 val)
222 {
223 	iowrite32(val, addr + offset);
224 }
225 
226 /**
227  * xudc_read32 - little endian read from device registers
228  * @addr: addr of device register
229  * Return: value at addr
230  */
231 static unsigned int xudc_read32(void __iomem *addr)
232 {
233 	return ioread32(addr);
234 }
235 
236 /**
237  * xudc_write32_be - big endian write to device registers
238  * @addr: base addr of device registers
239  * @offset: register offset
240  * @val: data to be written
241  */
242 static void xudc_write32_be(void __iomem *addr, u32 offset, u32 val)
243 {
244 	iowrite32be(val, addr + offset);
245 }
246 
247 /**
248  * xudc_read32_be - big endian read from device registers
249  * @addr: addr of device register
250  * Return: value at addr
251  */
252 static unsigned int xudc_read32_be(void __iomem *addr)
253 {
254 	return ioread32be(addr);
255 }
256 
257 /**
258  * xudc_wrstatus - Sets up the usb device status stages.
259  * @udc: pointer to the usb device controller structure.
260  */
261 static void xudc_wrstatus(struct xusb_udc *udc)
262 {
263 	struct xusb_ep *ep0 = &udc->ep[XUSB_EP_NUMBER_ZERO];
264 	u32 epcfgreg;
265 
266 	epcfgreg = udc->read_fn(udc->addr + ep0->offset)|
267 				XUSB_EP_CFG_DATA_TOGGLE_MASK;
268 	udc->write_fn(udc->addr, ep0->offset, epcfgreg);
269 	udc->write_fn(udc->addr, ep0->offset + XUSB_EP_BUF0COUNT_OFFSET, 0);
270 	udc->write_fn(udc->addr, XUSB_BUFFREADY_OFFSET, 1);
271 }
272 
273 /**
274  * xudc_epconfig - Configures the given endpoint.
275  * @ep: pointer to the usb device endpoint structure.
276  * @udc: pointer to the usb peripheral controller structure.
277  *
278  * This function configures a specific endpoint with the given configuration
279  * data.
280  */
281 static void xudc_epconfig(struct xusb_ep *ep, struct xusb_udc *udc)
282 {
283 	u32 epcfgreg;
284 
285 	/*
286 	 * Configure the end point direction, type, Max Packet Size and the
287 	 * EP buffer location.
288 	 */
289 	epcfgreg = ((ep->is_in << 29) | (ep->is_iso << 28) |
290 		   (ep->ep_usb.maxpacket << 15) | (ep->rambase));
291 	udc->write_fn(udc->addr, ep->offset, epcfgreg);
292 
293 	/* Set the Buffer count and the Buffer ready bits.*/
294 	udc->write_fn(udc->addr, ep->offset + XUSB_EP_BUF0COUNT_OFFSET,
295 		      ep->buffer0count);
296 	udc->write_fn(udc->addr, ep->offset + XUSB_EP_BUF1COUNT_OFFSET,
297 		      ep->buffer1count);
298 	if (ep->buffer0ready)
299 		udc->write_fn(udc->addr, XUSB_BUFFREADY_OFFSET,
300 			      1 << ep->epnumber);
301 	if (ep->buffer1ready)
302 		udc->write_fn(udc->addr, XUSB_BUFFREADY_OFFSET,
303 			      1 << (ep->epnumber + XUSB_STATUS_EP_BUFF2_SHIFT));
304 }
305 
306 /**
307  * xudc_start_dma - Starts DMA transfer.
308  * @ep: pointer to the usb device endpoint structure.
309  * @src: DMA source address.
310  * @dst: DMA destination address.
311  * @length: number of bytes to transfer.
312  *
313  * Return: 0 on success, error code on failure
314  *
315  * This function starts DMA transfer by writing to DMA source,
316  * destination and lenth registers.
317  */
318 static int xudc_start_dma(struct xusb_ep *ep, dma_addr_t src,
319 			  dma_addr_t dst, u32 length)
320 {
321 	struct xusb_udc *udc = ep->udc;
322 	int rc = 0;
323 	u32 timeout = 500;
324 	u32 reg;
325 
326 	/*
327 	 * Set the addresses in the DMA source and
328 	 * destination registers and then set the length
329 	 * into the DMA length register.
330 	 */
331 	udc->write_fn(udc->addr, XUSB_DMA_DSAR_ADDR_OFFSET, src);
332 	udc->write_fn(udc->addr, XUSB_DMA_DDAR_ADDR_OFFSET, dst);
333 	udc->write_fn(udc->addr, XUSB_DMA_LENGTH_OFFSET, length);
334 
335 	/*
336 	 * Wait till DMA transaction is complete and
337 	 * check whether the DMA transaction was
338 	 * successful.
339 	 */
340 	do {
341 		reg = udc->read_fn(udc->addr + XUSB_DMA_STATUS_OFFSET);
342 		if (!(reg &  XUSB_DMA_DMASR_BUSY))
343 			break;
344 
345 		/*
346 		 * We can't sleep here, because it's also called from
347 		 * interrupt context.
348 		 */
349 		timeout--;
350 		if (!timeout) {
351 			dev_err(udc->dev, "DMA timeout\n");
352 			return -ETIMEDOUT;
353 		}
354 		udelay(1);
355 	} while (1);
356 
357 	if ((udc->read_fn(udc->addr + XUSB_DMA_STATUS_OFFSET) &
358 			  XUSB_DMA_DMASR_ERROR) == XUSB_DMA_DMASR_ERROR){
359 		dev_err(udc->dev, "DMA Error\n");
360 		rc = -EINVAL;
361 	}
362 
363 	return rc;
364 }
365 
366 /**
367  * xudc_dma_send - Sends IN data using DMA.
368  * @ep: pointer to the usb device endpoint structure.
369  * @req: pointer to the usb request structure.
370  * @buffer: pointer to data to be sent.
371  * @length: number of bytes to send.
372  *
373  * Return: 0 on success, -EAGAIN if no buffer is free and error
374  *	   code on failure.
375  *
376  * This function sends data using DMA.
377  */
378 static int xudc_dma_send(struct xusb_ep *ep, struct xusb_req *req,
379 			 u8 *buffer, u32 length)
380 {
381 	u32 *eprambase;
382 	dma_addr_t src;
383 	dma_addr_t dst;
384 	struct xusb_udc *udc = ep->udc;
385 
386 	src = req->usb_req.dma + req->usb_req.actual;
387 	if (req->usb_req.length)
388 		dma_sync_single_for_device(udc->dev, src,
389 					   length, DMA_TO_DEVICE);
390 	if (!ep->curbufnum && !ep->buffer0ready) {
391 		/* Get the Buffer address and copy the transmit data.*/
392 		eprambase = (u32 __force *)(udc->addr + ep->rambase);
393 		dst = virt_to_phys(eprambase);
394 		udc->write_fn(udc->addr, ep->offset +
395 			      XUSB_EP_BUF0COUNT_OFFSET, length);
396 		udc->write_fn(udc->addr, XUSB_DMA_CONTROL_OFFSET,
397 			      XUSB_DMA_BRR_CTRL | (1 << ep->epnumber));
398 		ep->buffer0ready = 1;
399 		ep->curbufnum = 1;
400 	} else if (ep->curbufnum && !ep->buffer1ready) {
401 		/* Get the Buffer address and copy the transmit data.*/
402 		eprambase = (u32 __force *)(udc->addr + ep->rambase +
403 			     ep->ep_usb.maxpacket);
404 		dst = virt_to_phys(eprambase);
405 		udc->write_fn(udc->addr, ep->offset +
406 			      XUSB_EP_BUF1COUNT_OFFSET, length);
407 		udc->write_fn(udc->addr, XUSB_DMA_CONTROL_OFFSET,
408 			      XUSB_DMA_BRR_CTRL | (1 << (ep->epnumber +
409 			      XUSB_STATUS_EP_BUFF2_SHIFT)));
410 		ep->buffer1ready = 1;
411 		ep->curbufnum = 0;
412 	} else {
413 		/* None of ping pong buffers are ready currently .*/
414 		return -EAGAIN;
415 	}
416 
417 	return xudc_start_dma(ep, src, dst, length);
418 }
419 
420 /**
421  * xudc_dma_receive - Receives OUT data using DMA.
422  * @ep: pointer to the usb device endpoint structure.
423  * @req: pointer to the usb request structure.
424  * @buffer: pointer to storage buffer of received data.
425  * @length: number of bytes to receive.
426  *
427  * Return: 0 on success, -EAGAIN if no buffer is free and error
428  *	   code on failure.
429  *
430  * This function receives data using DMA.
431  */
432 static int xudc_dma_receive(struct xusb_ep *ep, struct xusb_req *req,
433 			    u8 *buffer, u32 length)
434 {
435 	u32 *eprambase;
436 	dma_addr_t src;
437 	dma_addr_t dst;
438 	struct xusb_udc *udc = ep->udc;
439 
440 	dst = req->usb_req.dma + req->usb_req.actual;
441 	if (!ep->curbufnum && !ep->buffer0ready) {
442 		/* Get the Buffer address and copy the transmit data */
443 		eprambase = (u32 __force *)(udc->addr + ep->rambase);
444 		src = virt_to_phys(eprambase);
445 		udc->write_fn(udc->addr, XUSB_DMA_CONTROL_OFFSET,
446 			      XUSB_DMA_BRR_CTRL | XUSB_DMA_READ_FROM_DPRAM |
447 			      (1 << ep->epnumber));
448 		ep->buffer0ready = 1;
449 		ep->curbufnum = 1;
450 	} else if (ep->curbufnum && !ep->buffer1ready) {
451 		/* Get the Buffer address and copy the transmit data */
452 		eprambase = (u32 __force *)(udc->addr +
453 			     ep->rambase + ep->ep_usb.maxpacket);
454 		src = virt_to_phys(eprambase);
455 		udc->write_fn(udc->addr, XUSB_DMA_CONTROL_OFFSET,
456 			      XUSB_DMA_BRR_CTRL | XUSB_DMA_READ_FROM_DPRAM |
457 			      (1 << (ep->epnumber +
458 			      XUSB_STATUS_EP_BUFF2_SHIFT)));
459 		ep->buffer1ready = 1;
460 		ep->curbufnum = 0;
461 	} else {
462 		/* None of the ping-pong buffers are ready currently */
463 		return -EAGAIN;
464 	}
465 
466 	return xudc_start_dma(ep, src, dst, length);
467 }
468 
469 /**
470  * xudc_eptxrx - Transmits or receives data to or from an endpoint.
471  * @ep: pointer to the usb endpoint configuration structure.
472  * @req: pointer to the usb request structure.
473  * @bufferptr: pointer to buffer containing the data to be sent.
474  * @bufferlen: The number of data bytes to be sent.
475  *
476  * Return: 0 on success, -EAGAIN if no buffer is free.
477  *
478  * This function copies the transmit/receive data to/from the end point buffer
479  * and enables the buffer for transmission/reception.
480  */
481 static int xudc_eptxrx(struct xusb_ep *ep, struct xusb_req *req,
482 		       u8 *bufferptr, u32 bufferlen)
483 {
484 	u32 *eprambase;
485 	u32 bytestosend;
486 	int rc = 0;
487 	struct xusb_udc *udc = ep->udc;
488 
489 	bytestosend = bufferlen;
490 	if (udc->dma_enabled) {
491 		if (ep->is_in)
492 			rc = xudc_dma_send(ep, req, bufferptr, bufferlen);
493 		else
494 			rc = xudc_dma_receive(ep, req, bufferptr, bufferlen);
495 		return rc;
496 	}
497 	/* Put the transmit buffer into the correct ping-pong buffer.*/
498 	if (!ep->curbufnum && !ep->buffer0ready) {
499 		/* Get the Buffer address and copy the transmit data.*/
500 		eprambase = (u32 __force *)(udc->addr + ep->rambase);
501 		if (ep->is_in) {
502 			memcpy(eprambase, bufferptr, bytestosend);
503 			udc->write_fn(udc->addr, ep->offset +
504 				      XUSB_EP_BUF0COUNT_OFFSET, bufferlen);
505 		} else {
506 			memcpy(bufferptr, eprambase, bytestosend);
507 		}
508 		/*
509 		 * Enable the buffer for transmission.
510 		 */
511 		udc->write_fn(udc->addr, XUSB_BUFFREADY_OFFSET,
512 			      1 << ep->epnumber);
513 		ep->buffer0ready = 1;
514 		ep->curbufnum = 1;
515 	} else if (ep->curbufnum && !ep->buffer1ready) {
516 		/* Get the Buffer address and copy the transmit data.*/
517 		eprambase = (u32 __force *)(udc->addr + ep->rambase +
518 			     ep->ep_usb.maxpacket);
519 		if (ep->is_in) {
520 			memcpy(eprambase, bufferptr, bytestosend);
521 			udc->write_fn(udc->addr, ep->offset +
522 				      XUSB_EP_BUF1COUNT_OFFSET, bufferlen);
523 		} else {
524 			memcpy(bufferptr, eprambase, bytestosend);
525 		}
526 		/*
527 		 * Enable the buffer for transmission.
528 		 */
529 		udc->write_fn(udc->addr, XUSB_BUFFREADY_OFFSET,
530 			      1 << (ep->epnumber + XUSB_STATUS_EP_BUFF2_SHIFT));
531 		ep->buffer1ready = 1;
532 		ep->curbufnum = 0;
533 	} else {
534 		/* None of the ping-pong buffers are ready currently */
535 		return -EAGAIN;
536 	}
537 	return rc;
538 }
539 
540 /**
541  * xudc_done - Exeutes the endpoint data transfer completion tasks.
542  * @ep: pointer to the usb device endpoint structure.
543  * @req: pointer to the usb request structure.
544  * @status: Status of the data transfer.
545  *
546  * Deletes the message from the queue and updates data transfer completion
547  * status.
548  */
549 static void xudc_done(struct xusb_ep *ep, struct xusb_req *req, int status)
550 {
551 	struct xusb_udc *udc = ep->udc;
552 
553 	list_del_init(&req->queue);
554 
555 	if (req->usb_req.status == -EINPROGRESS)
556 		req->usb_req.status = status;
557 	else
558 		status = req->usb_req.status;
559 
560 	if (status && status != -ESHUTDOWN)
561 		dev_dbg(udc->dev, "%s done %p, status %d\n",
562 			ep->ep_usb.name, req, status);
563 	/* unmap request if DMA is present*/
564 	if (udc->dma_enabled && ep->epnumber && req->usb_req.length)
565 		usb_gadget_unmap_request(&udc->gadget, &req->usb_req,
566 					 ep->is_in);
567 
568 	if (req->usb_req.complete) {
569 		spin_unlock(&udc->lock);
570 		req->usb_req.complete(&ep->ep_usb, &req->usb_req);
571 		spin_lock(&udc->lock);
572 	}
573 }
574 
575 /**
576  * xudc_read_fifo - Reads the data from the given endpoint buffer.
577  * @ep: pointer to the usb device endpoint structure.
578  * @req: pointer to the usb request structure.
579  *
580  * Return: 0 if request is completed and -EAGAIN if not completed.
581  *
582  * Pulls OUT packet data from the endpoint buffer.
583  */
584 static int xudc_read_fifo(struct xusb_ep *ep, struct xusb_req *req)
585 {
586 	u8 *buf;
587 	u32 is_short, count, bufferspace;
588 	u8 bufoffset;
589 	u8 two_pkts = 0;
590 	int ret;
591 	int retval = -EAGAIN;
592 	struct xusb_udc *udc = ep->udc;
593 
594 	if (ep->buffer0ready && ep->buffer1ready) {
595 		dev_dbg(udc->dev, "Packet NOT ready!\n");
596 		return retval;
597 	}
598 top:
599 	if (ep->curbufnum)
600 		bufoffset = XUSB_EP_BUF1COUNT_OFFSET;
601 	else
602 		bufoffset = XUSB_EP_BUF0COUNT_OFFSET;
603 
604 	count = udc->read_fn(udc->addr + ep->offset + bufoffset);
605 
606 	if (!ep->buffer0ready && !ep->buffer1ready)
607 		two_pkts = 1;
608 
609 	buf = req->usb_req.buf + req->usb_req.actual;
610 	prefetchw(buf);
611 	bufferspace = req->usb_req.length - req->usb_req.actual;
612 	is_short = count < ep->ep_usb.maxpacket;
613 
614 	if (unlikely(!bufferspace)) {
615 		/*
616 		 * This happens when the driver's buffer
617 		 * is smaller than what the host sent.
618 		 * discard the extra data.
619 		 */
620 		if (req->usb_req.status != -EOVERFLOW)
621 			dev_dbg(udc->dev, "%s overflow %d\n",
622 				ep->ep_usb.name, count);
623 		req->usb_req.status = -EOVERFLOW;
624 		xudc_done(ep, req, -EOVERFLOW);
625 		return 0;
626 	}
627 
628 	ret = xudc_eptxrx(ep, req, buf, count);
629 	switch (ret) {
630 	case 0:
631 		req->usb_req.actual += min(count, bufferspace);
632 		dev_dbg(udc->dev, "read %s, %d bytes%s req %p %d/%d\n",
633 			ep->ep_usb.name, count, is_short ? "/S" : "", req,
634 			req->usb_req.actual, req->usb_req.length);
635 
636 		/* Completion */
637 		if ((req->usb_req.actual == req->usb_req.length) || is_short) {
638 			if (udc->dma_enabled && req->usb_req.length)
639 				dma_sync_single_for_cpu(udc->dev,
640 							req->usb_req.dma,
641 							req->usb_req.actual,
642 							DMA_FROM_DEVICE);
643 			xudc_done(ep, req, 0);
644 			return 0;
645 		}
646 		if (two_pkts) {
647 			two_pkts = 0;
648 			goto top;
649 		}
650 		break;
651 	case -EAGAIN:
652 		dev_dbg(udc->dev, "receive busy\n");
653 		break;
654 	case -EINVAL:
655 	case -ETIMEDOUT:
656 		/* DMA error, dequeue the request */
657 		xudc_done(ep, req, -ECONNRESET);
658 		retval = 0;
659 		break;
660 	}
661 
662 	return retval;
663 }
664 
665 /**
666  * xudc_write_fifo - Writes data into the given endpoint buffer.
667  * @ep: pointer to the usb device endpoint structure.
668  * @req: pointer to the usb request structure.
669  *
670  * Return: 0 if request is completed and -EAGAIN if not completed.
671  *
672  * Loads endpoint buffer for an IN packet.
673  */
674 static int xudc_write_fifo(struct xusb_ep *ep, struct xusb_req *req)
675 {
676 	u32 max;
677 	u32 length;
678 	int ret;
679 	int retval = -EAGAIN;
680 	struct xusb_udc *udc = ep->udc;
681 	int is_last, is_short = 0;
682 	u8 *buf;
683 
684 	max = le16_to_cpu(ep->desc->wMaxPacketSize);
685 	buf = req->usb_req.buf + req->usb_req.actual;
686 	prefetch(buf);
687 	length = req->usb_req.length - req->usb_req.actual;
688 	length = min(length, max);
689 
690 	ret = xudc_eptxrx(ep, req, buf, length);
691 	switch (ret) {
692 	case 0:
693 		req->usb_req.actual += length;
694 		if (unlikely(length != max)) {
695 			is_last = is_short = 1;
696 		} else {
697 			if (likely(req->usb_req.length !=
698 				   req->usb_req.actual) || req->usb_req.zero)
699 				is_last = 0;
700 			else
701 				is_last = 1;
702 		}
703 		dev_dbg(udc->dev, "%s: wrote %s %d bytes%s%s %d left %p\n",
704 			__func__, ep->ep_usb.name, length, is_last ? "/L" : "",
705 			is_short ? "/S" : "",
706 			req->usb_req.length - req->usb_req.actual, req);
707 		/* completion */
708 		if (is_last) {
709 			xudc_done(ep, req, 0);
710 			retval = 0;
711 		}
712 		break;
713 	case -EAGAIN:
714 		dev_dbg(udc->dev, "Send busy\n");
715 		break;
716 	case -EINVAL:
717 	case -ETIMEDOUT:
718 		/* DMA error, dequeue the request */
719 		xudc_done(ep, req, -ECONNRESET);
720 		retval = 0;
721 		break;
722 	}
723 
724 	return retval;
725 }
726 
727 /**
728  * xudc_nuke - Cleans up the data transfer message list.
729  * @ep: pointer to the usb device endpoint structure.
730  * @status: Status of the data transfer.
731  */
732 static void xudc_nuke(struct xusb_ep *ep, int status)
733 {
734 	struct xusb_req *req;
735 
736 	while (!list_empty(&ep->queue)) {
737 		req = list_first_entry(&ep->queue, struct xusb_req, queue);
738 		xudc_done(ep, req, status);
739 	}
740 }
741 
742 /**
743  * xudc_ep_set_halt - Stalls/unstalls the given endpoint.
744  * @_ep: pointer to the usb device endpoint structure.
745  * @value: value to indicate stall/unstall.
746  *
747  * Return: 0 for success and error value on failure
748  */
749 static int xudc_ep_set_halt(struct usb_ep *_ep, int value)
750 {
751 	struct xusb_ep *ep = to_xusb_ep(_ep);
752 	struct xusb_udc *udc;
753 	unsigned long flags;
754 	u32 epcfgreg;
755 
756 	if (!_ep || (!ep->desc && ep->epnumber)) {
757 		pr_debug("%s: bad ep or descriptor\n", __func__);
758 		return -EINVAL;
759 	}
760 	udc = ep->udc;
761 
762 	if (ep->is_in && (!list_empty(&ep->queue)) && value) {
763 		dev_dbg(udc->dev, "requests pending can't halt\n");
764 		return -EAGAIN;
765 	}
766 
767 	if (ep->buffer0ready || ep->buffer1ready) {
768 		dev_dbg(udc->dev, "HW buffers busy can't halt\n");
769 		return -EAGAIN;
770 	}
771 
772 	spin_lock_irqsave(&udc->lock, flags);
773 
774 	if (value) {
775 		/* Stall the device.*/
776 		epcfgreg = udc->read_fn(udc->addr + ep->offset);
777 		epcfgreg |= XUSB_EP_CFG_STALL_MASK;
778 		udc->write_fn(udc->addr, ep->offset, epcfgreg);
779 	} else {
780 		/* Unstall the device.*/
781 		epcfgreg = udc->read_fn(udc->addr + ep->offset);
782 		epcfgreg &= ~XUSB_EP_CFG_STALL_MASK;
783 		udc->write_fn(udc->addr, ep->offset, epcfgreg);
784 		if (ep->epnumber) {
785 			/* Reset the toggle bit.*/
786 			epcfgreg = udc->read_fn(ep->udc->addr + ep->offset);
787 			epcfgreg &= ~XUSB_EP_CFG_DATA_TOGGLE_MASK;
788 			udc->write_fn(udc->addr, ep->offset, epcfgreg);
789 		}
790 	}
791 
792 	spin_unlock_irqrestore(&udc->lock, flags);
793 	return 0;
794 }
795 
796 /**
797  * __xudc_ep_enable - Enables the given endpoint.
798  * @ep: pointer to the xusb endpoint structure.
799  * @desc: pointer to usb endpoint descriptor.
800  *
801  * Return: 0 for success and error value on failure
802  */
803 static int __xudc_ep_enable(struct xusb_ep *ep,
804 			    const struct usb_endpoint_descriptor *desc)
805 {
806 	struct xusb_udc *udc = ep->udc;
807 	u32 tmp;
808 	u32 epcfg;
809 	u32 ier;
810 	u16 maxpacket;
811 
812 	ep->is_in = ((desc->bEndpointAddress & USB_DIR_IN) != 0);
813 	/* Bit 3...0:endpoint number */
814 	ep->epnumber = (desc->bEndpointAddress & 0x0f);
815 	ep->desc = desc;
816 	ep->ep_usb.desc = desc;
817 	tmp = desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK;
818 	ep->ep_usb.maxpacket = maxpacket = le16_to_cpu(desc->wMaxPacketSize);
819 
820 	switch (tmp) {
821 	case USB_ENDPOINT_XFER_CONTROL:
822 		dev_dbg(udc->dev, "only one control endpoint\n");
823 		/* NON- ISO */
824 		ep->is_iso = 0;
825 		return -EINVAL;
826 	case USB_ENDPOINT_XFER_INT:
827 		/* NON- ISO */
828 		ep->is_iso = 0;
829 		if (maxpacket > 64) {
830 			dev_dbg(udc->dev, "bogus maxpacket %d\n", maxpacket);
831 			return -EINVAL;
832 		}
833 		break;
834 	case USB_ENDPOINT_XFER_BULK:
835 		/* NON- ISO */
836 		ep->is_iso = 0;
837 		if (!(is_power_of_2(maxpacket) && maxpacket >= 8 &&
838 				maxpacket <= 512)) {
839 			dev_dbg(udc->dev, "bogus maxpacket %d\n", maxpacket);
840 			return -EINVAL;
841 		}
842 		break;
843 	case USB_ENDPOINT_XFER_ISOC:
844 		/* ISO */
845 		ep->is_iso = 1;
846 		break;
847 	}
848 
849 	ep->buffer0ready = false;
850 	ep->buffer1ready = false;
851 	ep->curbufnum = 0;
852 	ep->rambase = rambase[ep->epnumber];
853 	xudc_epconfig(ep, udc);
854 
855 	dev_dbg(udc->dev, "Enable Endpoint %d max pkt is %d\n",
856 		ep->epnumber, maxpacket);
857 
858 	/* Enable the End point.*/
859 	epcfg = udc->read_fn(udc->addr + ep->offset);
860 	epcfg |= XUSB_EP_CFG_VALID_MASK;
861 	udc->write_fn(udc->addr, ep->offset, epcfg);
862 	if (ep->epnumber)
863 		ep->rambase <<= 2;
864 
865 	/* Enable buffer completion interrupts for endpoint */
866 	ier = udc->read_fn(udc->addr + XUSB_IER_OFFSET);
867 	ier |= (XUSB_STATUS_INTR_BUFF_COMP_SHIFT_MASK << ep->epnumber);
868 	udc->write_fn(udc->addr, XUSB_IER_OFFSET, ier);
869 
870 	/* for OUT endpoint set buffers ready to receive */
871 	if (ep->epnumber && !ep->is_in) {
872 		udc->write_fn(udc->addr, XUSB_BUFFREADY_OFFSET,
873 			      1 << ep->epnumber);
874 		ep->buffer0ready = true;
875 		udc->write_fn(udc->addr, XUSB_BUFFREADY_OFFSET,
876 			     (1 << (ep->epnumber +
877 			      XUSB_STATUS_EP_BUFF2_SHIFT)));
878 		ep->buffer1ready = true;
879 	}
880 
881 	return 0;
882 }
883 
884 /**
885  * xudc_ep_enable - Enables the given endpoint.
886  * @_ep: pointer to the usb endpoint structure.
887  * @desc: pointer to usb endpoint descriptor.
888  *
889  * Return: 0 for success and error value on failure
890  */
891 static int xudc_ep_enable(struct usb_ep *_ep,
892 			  const struct usb_endpoint_descriptor *desc)
893 {
894 	struct xusb_ep *ep;
895 	struct xusb_udc *udc;
896 	unsigned long flags;
897 	int ret;
898 
899 	if (!_ep || !desc || desc->bDescriptorType != USB_DT_ENDPOINT) {
900 		pr_debug("%s: bad ep or descriptor\n", __func__);
901 		return -EINVAL;
902 	}
903 
904 	ep = to_xusb_ep(_ep);
905 	udc = ep->udc;
906 
907 	if (!udc->driver || udc->gadget.speed == USB_SPEED_UNKNOWN) {
908 		dev_dbg(udc->dev, "bogus device state\n");
909 		return -ESHUTDOWN;
910 	}
911 
912 	spin_lock_irqsave(&udc->lock, flags);
913 	ret = __xudc_ep_enable(ep, desc);
914 	spin_unlock_irqrestore(&udc->lock, flags);
915 
916 	return ret;
917 }
918 
919 /**
920  * xudc_ep_disable - Disables the given endpoint.
921  * @_ep: pointer to the usb endpoint structure.
922  *
923  * Return: 0 for success and error value on failure
924  */
925 static int xudc_ep_disable(struct usb_ep *_ep)
926 {
927 	struct xusb_ep *ep;
928 	unsigned long flags;
929 	u32 epcfg;
930 	struct xusb_udc *udc;
931 
932 	if (!_ep) {
933 		pr_debug("%s: invalid ep\n", __func__);
934 		return -EINVAL;
935 	}
936 
937 	ep = to_xusb_ep(_ep);
938 	udc = ep->udc;
939 
940 	spin_lock_irqsave(&udc->lock, flags);
941 
942 	xudc_nuke(ep, -ESHUTDOWN);
943 
944 	/* Restore the endpoint's pristine config */
945 	ep->desc = NULL;
946 	ep->ep_usb.desc = NULL;
947 
948 	dev_dbg(udc->dev, "USB Ep %d disable\n ", ep->epnumber);
949 	/* Disable the endpoint.*/
950 	epcfg = udc->read_fn(udc->addr + ep->offset);
951 	epcfg &= ~XUSB_EP_CFG_VALID_MASK;
952 	udc->write_fn(udc->addr, ep->offset, epcfg);
953 
954 	spin_unlock_irqrestore(&udc->lock, flags);
955 	return 0;
956 }
957 
958 /**
959  * xudc_ep_alloc_request - Initializes the request queue.
960  * @_ep: pointer to the usb endpoint structure.
961  * @gfp_flags: Flags related to the request call.
962  *
963  * Return: pointer to request structure on success and a NULL on failure.
964  */
965 static struct usb_request *xudc_ep_alloc_request(struct usb_ep *_ep,
966 						 gfp_t gfp_flags)
967 {
968 	struct xusb_ep *ep = to_xusb_ep(_ep);
969 	struct xusb_req *req;
970 
971 	req = kzalloc(sizeof(*req), gfp_flags);
972 	if (!req)
973 		return NULL;
974 
975 	req->ep = ep;
976 	INIT_LIST_HEAD(&req->queue);
977 	return &req->usb_req;
978 }
979 
980 /**
981  * xudc_free_request - Releases the request from queue.
982  * @_ep: pointer to the usb device endpoint structure.
983  * @_req: pointer to the usb request structure.
984  */
985 static void xudc_free_request(struct usb_ep *_ep, struct usb_request *_req)
986 {
987 	struct xusb_req *req = to_xusb_req(_req);
988 
989 	kfree(req);
990 }
991 
992 /**
993  * __xudc_ep0_queue - Adds the request to endpoint 0 queue.
994  * @ep0: pointer to the xusb endpoint 0 structure.
995  * @req: pointer to the xusb request structure.
996  *
997  * Return: 0 for success and error value on failure
998  */
999 static int __xudc_ep0_queue(struct xusb_ep *ep0, struct xusb_req *req)
1000 {
1001 	struct xusb_udc *udc = ep0->udc;
1002 	u32 length;
1003 	u8 *corebuf;
1004 
1005 	if (!udc->driver || udc->gadget.speed == USB_SPEED_UNKNOWN) {
1006 		dev_dbg(udc->dev, "%s, bogus device state\n", __func__);
1007 		return -EINVAL;
1008 	}
1009 	if (!list_empty(&ep0->queue)) {
1010 		dev_dbg(udc->dev, "%s:ep0 busy\n", __func__);
1011 		return -EBUSY;
1012 	}
1013 
1014 	req->usb_req.status = -EINPROGRESS;
1015 	req->usb_req.actual = 0;
1016 
1017 	list_add_tail(&req->queue, &ep0->queue);
1018 
1019 	if (udc->setup.bRequestType & USB_DIR_IN) {
1020 		prefetch(req->usb_req.buf);
1021 		length = req->usb_req.length;
1022 		corebuf = (void __force *) ((ep0->rambase << 2) +
1023 			   udc->addr);
1024 		length = req->usb_req.actual = min_t(u32, length,
1025 						     EP0_MAX_PACKET);
1026 		memcpy(corebuf, req->usb_req.buf, length);
1027 		udc->write_fn(udc->addr, XUSB_EP_BUF0COUNT_OFFSET, length);
1028 		udc->write_fn(udc->addr, XUSB_BUFFREADY_OFFSET, 1);
1029 	} else {
1030 		if (udc->setup.wLength) {
1031 			/* Enable EP0 buffer to receive data */
1032 			udc->write_fn(udc->addr, XUSB_EP_BUF0COUNT_OFFSET, 0);
1033 			udc->write_fn(udc->addr, XUSB_BUFFREADY_OFFSET, 1);
1034 		} else {
1035 			xudc_wrstatus(udc);
1036 		}
1037 	}
1038 
1039 	return 0;
1040 }
1041 
1042 /**
1043  * xudc_ep0_queue - Adds the request to endpoint 0 queue.
1044  * @_ep: pointer to the usb endpoint 0 structure.
1045  * @_req: pointer to the usb request structure.
1046  * @gfp_flags: Flags related to the request call.
1047  *
1048  * Return: 0 for success and error value on failure
1049  */
1050 static int xudc_ep0_queue(struct usb_ep *_ep, struct usb_request *_req,
1051 			  gfp_t gfp_flags)
1052 {
1053 	struct xusb_req *req	= to_xusb_req(_req);
1054 	struct xusb_ep	*ep0	= to_xusb_ep(_ep);
1055 	struct xusb_udc *udc	= ep0->udc;
1056 	unsigned long flags;
1057 	int ret;
1058 
1059 	spin_lock_irqsave(&udc->lock, flags);
1060 	ret = __xudc_ep0_queue(ep0, req);
1061 	spin_unlock_irqrestore(&udc->lock, flags);
1062 
1063 	return ret;
1064 }
1065 
1066 /**
1067  * xudc_ep_queue - Adds the request to endpoint queue.
1068  * @_ep: pointer to the usb endpoint structure.
1069  * @_req: pointer to the usb request structure.
1070  * @gfp_flags: Flags related to the request call.
1071  *
1072  * Return: 0 for success and error value on failure
1073  */
1074 static int xudc_ep_queue(struct usb_ep *_ep, struct usb_request *_req,
1075 			 gfp_t gfp_flags)
1076 {
1077 	struct xusb_req *req = to_xusb_req(_req);
1078 	struct xusb_ep	*ep  = to_xusb_ep(_ep);
1079 	struct xusb_udc *udc = ep->udc;
1080 	int  ret;
1081 	unsigned long flags;
1082 
1083 	if (!ep->desc) {
1084 		dev_dbg(udc->dev, "%s: queuing request to disabled %s\n",
1085 			__func__, ep->name);
1086 		return -ESHUTDOWN;
1087 	}
1088 
1089 	if (!udc->driver || udc->gadget.speed == USB_SPEED_UNKNOWN) {
1090 		dev_dbg(udc->dev, "%s, bogus device state\n", __func__);
1091 		return -EINVAL;
1092 	}
1093 
1094 	spin_lock_irqsave(&udc->lock, flags);
1095 
1096 	_req->status = -EINPROGRESS;
1097 	_req->actual = 0;
1098 
1099 	if (udc->dma_enabled) {
1100 		ret = usb_gadget_map_request(&udc->gadget, &req->usb_req,
1101 					     ep->is_in);
1102 		if (ret) {
1103 			dev_dbg(udc->dev, "gadget_map failed ep%d\n",
1104 				ep->epnumber);
1105 			spin_unlock_irqrestore(&udc->lock, flags);
1106 			return -EAGAIN;
1107 		}
1108 	}
1109 
1110 	if (list_empty(&ep->queue)) {
1111 		if (ep->is_in) {
1112 			dev_dbg(udc->dev, "xudc_write_fifo from ep_queue\n");
1113 			if (!xudc_write_fifo(ep, req))
1114 				req = NULL;
1115 		} else {
1116 			dev_dbg(udc->dev, "xudc_read_fifo from ep_queue\n");
1117 			if (!xudc_read_fifo(ep, req))
1118 				req = NULL;
1119 		}
1120 	}
1121 
1122 	if (req != NULL)
1123 		list_add_tail(&req->queue, &ep->queue);
1124 
1125 	spin_unlock_irqrestore(&udc->lock, flags);
1126 	return 0;
1127 }
1128 
1129 /**
1130  * xudc_ep_dequeue - Removes the request from the queue.
1131  * @_ep: pointer to the usb device endpoint structure.
1132  * @_req: pointer to the usb request structure.
1133  *
1134  * Return: 0 for success and error value on failure
1135  */
1136 static int xudc_ep_dequeue(struct usb_ep *_ep, struct usb_request *_req)
1137 {
1138 	struct xusb_ep *ep	= to_xusb_ep(_ep);
1139 	struct xusb_req *req	= NULL;
1140 	struct xusb_req *iter;
1141 	struct xusb_udc *udc	= ep->udc;
1142 	unsigned long flags;
1143 
1144 	spin_lock_irqsave(&udc->lock, flags);
1145 	/* Make sure it's actually queued on this endpoint */
1146 	list_for_each_entry(iter, &ep->queue, queue) {
1147 		if (&iter->usb_req != _req)
1148 			continue;
1149 		req = iter;
1150 		break;
1151 	}
1152 	if (!req) {
1153 		spin_unlock_irqrestore(&udc->lock, flags);
1154 		return -EINVAL;
1155 	}
1156 	xudc_done(ep, req, -ECONNRESET);
1157 	spin_unlock_irqrestore(&udc->lock, flags);
1158 
1159 	return 0;
1160 }
1161 
1162 /**
1163  * xudc_ep0_enable - Enables the given endpoint.
1164  * @ep: pointer to the usb endpoint structure.
1165  * @desc: pointer to usb endpoint descriptor.
1166  *
1167  * Return: error always.
1168  *
1169  * endpoint 0 enable should not be called by gadget layer.
1170  */
1171 static int xudc_ep0_enable(struct usb_ep *ep,
1172 			   const struct usb_endpoint_descriptor *desc)
1173 {
1174 	return -EINVAL;
1175 }
1176 
1177 /**
1178  * xudc_ep0_disable - Disables the given endpoint.
1179  * @ep: pointer to the usb endpoint structure.
1180  *
1181  * Return: error always.
1182  *
1183  * endpoint 0 disable should not be called by gadget layer.
1184  */
1185 static int xudc_ep0_disable(struct usb_ep *ep)
1186 {
1187 	return -EINVAL;
1188 }
1189 
1190 static const struct usb_ep_ops xusb_ep0_ops = {
1191 	.enable		= xudc_ep0_enable,
1192 	.disable	= xudc_ep0_disable,
1193 	.alloc_request	= xudc_ep_alloc_request,
1194 	.free_request	= xudc_free_request,
1195 	.queue		= xudc_ep0_queue,
1196 	.dequeue	= xudc_ep_dequeue,
1197 	.set_halt	= xudc_ep_set_halt,
1198 };
1199 
1200 static const struct usb_ep_ops xusb_ep_ops = {
1201 	.enable		= xudc_ep_enable,
1202 	.disable	= xudc_ep_disable,
1203 	.alloc_request	= xudc_ep_alloc_request,
1204 	.free_request	= xudc_free_request,
1205 	.queue		= xudc_ep_queue,
1206 	.dequeue	= xudc_ep_dequeue,
1207 	.set_halt	= xudc_ep_set_halt,
1208 };
1209 
1210 /**
1211  * xudc_get_frame - Reads the current usb frame number.
1212  * @gadget: pointer to the usb gadget structure.
1213  *
1214  * Return: current frame number for success and error value on failure.
1215  */
1216 static int xudc_get_frame(struct usb_gadget *gadget)
1217 {
1218 	struct xusb_udc *udc;
1219 	int frame;
1220 
1221 	if (!gadget)
1222 		return -ENODEV;
1223 
1224 	udc = to_udc(gadget);
1225 	frame = udc->read_fn(udc->addr + XUSB_FRAMENUM_OFFSET);
1226 	return frame;
1227 }
1228 
1229 /**
1230  * xudc_wakeup - Send remote wakeup signal to host
1231  * @gadget: pointer to the usb gadget structure.
1232  *
1233  * Return: 0 on success and error on failure
1234  */
1235 static int xudc_wakeup(struct usb_gadget *gadget)
1236 {
1237 	struct xusb_udc *udc = to_udc(gadget);
1238 	u32 crtlreg;
1239 	int status = -EINVAL;
1240 	unsigned long flags;
1241 
1242 	spin_lock_irqsave(&udc->lock, flags);
1243 
1244 	/* Remote wake up not enabled by host */
1245 	if (!udc->remote_wkp)
1246 		goto done;
1247 
1248 	crtlreg = udc->read_fn(udc->addr + XUSB_CONTROL_OFFSET);
1249 	crtlreg |= XUSB_CONTROL_USB_RMTWAKE_MASK;
1250 	/* set remote wake up bit */
1251 	udc->write_fn(udc->addr, XUSB_CONTROL_OFFSET, crtlreg);
1252 	/*
1253 	 * wait for a while and reset remote wake up bit since this bit
1254 	 * is not cleared by HW after sending remote wakeup to host.
1255 	 */
1256 	mdelay(2);
1257 
1258 	crtlreg &= ~XUSB_CONTROL_USB_RMTWAKE_MASK;
1259 	udc->write_fn(udc->addr, XUSB_CONTROL_OFFSET, crtlreg);
1260 	status = 0;
1261 done:
1262 	spin_unlock_irqrestore(&udc->lock, flags);
1263 	return status;
1264 }
1265 
1266 /**
1267  * xudc_pullup - start/stop USB traffic
1268  * @gadget: pointer to the usb gadget structure.
1269  * @is_on: flag to start or stop
1270  *
1271  * Return: 0 always
1272  *
1273  * This function starts/stops SIE engine of IP based on is_on.
1274  */
1275 static int xudc_pullup(struct usb_gadget *gadget, int is_on)
1276 {
1277 	struct xusb_udc *udc = to_udc(gadget);
1278 	unsigned long flags;
1279 	u32 crtlreg;
1280 
1281 	spin_lock_irqsave(&udc->lock, flags);
1282 
1283 	crtlreg = udc->read_fn(udc->addr + XUSB_CONTROL_OFFSET);
1284 	if (is_on)
1285 		crtlreg |= XUSB_CONTROL_USB_READY_MASK;
1286 	else
1287 		crtlreg &= ~XUSB_CONTROL_USB_READY_MASK;
1288 
1289 	udc->write_fn(udc->addr, XUSB_CONTROL_OFFSET, crtlreg);
1290 
1291 	spin_unlock_irqrestore(&udc->lock, flags);
1292 
1293 	return 0;
1294 }
1295 
1296 /**
1297  * xudc_eps_init - initialize endpoints.
1298  * @udc: pointer to the usb device controller structure.
1299  */
1300 static void xudc_eps_init(struct xusb_udc *udc)
1301 {
1302 	u32 ep_number;
1303 
1304 	INIT_LIST_HEAD(&udc->gadget.ep_list);
1305 
1306 	for (ep_number = 0; ep_number < XUSB_MAX_ENDPOINTS; ep_number++) {
1307 		struct xusb_ep *ep = &udc->ep[ep_number];
1308 
1309 		if (ep_number) {
1310 			list_add_tail(&ep->ep_usb.ep_list,
1311 				      &udc->gadget.ep_list);
1312 			usb_ep_set_maxpacket_limit(&ep->ep_usb,
1313 						  (unsigned short) ~0);
1314 			snprintf(ep->name, EPNAME_SIZE, "ep%d", ep_number);
1315 			ep->ep_usb.name = ep->name;
1316 			ep->ep_usb.ops = &xusb_ep_ops;
1317 
1318 			ep->ep_usb.caps.type_iso = true;
1319 			ep->ep_usb.caps.type_bulk = true;
1320 			ep->ep_usb.caps.type_int = true;
1321 		} else {
1322 			ep->ep_usb.name = ep0name;
1323 			usb_ep_set_maxpacket_limit(&ep->ep_usb, EP0_MAX_PACKET);
1324 			ep->ep_usb.ops = &xusb_ep0_ops;
1325 
1326 			ep->ep_usb.caps.type_control = true;
1327 		}
1328 
1329 		ep->ep_usb.caps.dir_in = true;
1330 		ep->ep_usb.caps.dir_out = true;
1331 
1332 		ep->udc = udc;
1333 		ep->epnumber = ep_number;
1334 		ep->desc = NULL;
1335 		/*
1336 		 * The configuration register address offset between
1337 		 * each endpoint is 0x10.
1338 		 */
1339 		ep->offset = XUSB_EP0_CONFIG_OFFSET + (ep_number * 0x10);
1340 		ep->is_in = 0;
1341 		ep->is_iso = 0;
1342 		ep->maxpacket = 0;
1343 		xudc_epconfig(ep, udc);
1344 
1345 		/* Initialize one queue per endpoint */
1346 		INIT_LIST_HEAD(&ep->queue);
1347 	}
1348 }
1349 
1350 /**
1351  * xudc_stop_activity - Stops any further activity on the device.
1352  * @udc: pointer to the usb device controller structure.
1353  */
1354 static void xudc_stop_activity(struct xusb_udc *udc)
1355 {
1356 	int i;
1357 	struct xusb_ep *ep;
1358 
1359 	for (i = 0; i < XUSB_MAX_ENDPOINTS; i++) {
1360 		ep = &udc->ep[i];
1361 		xudc_nuke(ep, -ESHUTDOWN);
1362 	}
1363 }
1364 
1365 /**
1366  * xudc_start - Starts the device.
1367  * @gadget: pointer to the usb gadget structure
1368  * @driver: pointer to gadget driver structure
1369  *
1370  * Return: zero on success and error on failure
1371  */
1372 static int xudc_start(struct usb_gadget *gadget,
1373 		      struct usb_gadget_driver *driver)
1374 {
1375 	struct xusb_udc *udc	= to_udc(gadget);
1376 	struct xusb_ep *ep0	= &udc->ep[XUSB_EP_NUMBER_ZERO];
1377 	const struct usb_endpoint_descriptor *desc = &config_bulk_out_desc;
1378 	unsigned long flags;
1379 	int ret = 0;
1380 
1381 	spin_lock_irqsave(&udc->lock, flags);
1382 
1383 	if (udc->driver) {
1384 		dev_err(udc->dev, "%s is already bound to %s\n",
1385 			udc->gadget.name, udc->driver->driver.name);
1386 		ret = -EBUSY;
1387 		goto err;
1388 	}
1389 
1390 	/* hook up the driver */
1391 	udc->driver = driver;
1392 	udc->gadget.speed = driver->max_speed;
1393 
1394 	/* Enable the control endpoint. */
1395 	ret = __xudc_ep_enable(ep0, desc);
1396 
1397 	/* Set device address and remote wakeup to 0 */
1398 	udc->write_fn(udc->addr, XUSB_ADDRESS_OFFSET, 0);
1399 	udc->remote_wkp = 0;
1400 err:
1401 	spin_unlock_irqrestore(&udc->lock, flags);
1402 	return ret;
1403 }
1404 
1405 /**
1406  * xudc_stop - stops the device.
1407  * @gadget: pointer to the usb gadget structure
1408  *
1409  * Return: zero always
1410  */
1411 static int xudc_stop(struct usb_gadget *gadget)
1412 {
1413 	struct xusb_udc *udc = to_udc(gadget);
1414 	unsigned long flags;
1415 
1416 	spin_lock_irqsave(&udc->lock, flags);
1417 
1418 	udc->gadget.speed = USB_SPEED_UNKNOWN;
1419 	udc->driver = NULL;
1420 
1421 	/* Set device address and remote wakeup to 0 */
1422 	udc->write_fn(udc->addr, XUSB_ADDRESS_OFFSET, 0);
1423 	udc->remote_wkp = 0;
1424 
1425 	xudc_stop_activity(udc);
1426 
1427 	spin_unlock_irqrestore(&udc->lock, flags);
1428 
1429 	return 0;
1430 }
1431 
1432 static const struct usb_gadget_ops xusb_udc_ops = {
1433 	.get_frame	= xudc_get_frame,
1434 	.wakeup		= xudc_wakeup,
1435 	.pullup		= xudc_pullup,
1436 	.udc_start	= xudc_start,
1437 	.udc_stop	= xudc_stop,
1438 };
1439 
1440 /**
1441  * xudc_clear_stall_all_ep - clears stall of every endpoint.
1442  * @udc: pointer to the udc structure.
1443  */
1444 static void xudc_clear_stall_all_ep(struct xusb_udc *udc)
1445 {
1446 	struct xusb_ep *ep;
1447 	u32 epcfgreg;
1448 	int i;
1449 
1450 	for (i = 0; i < XUSB_MAX_ENDPOINTS; i++) {
1451 		ep = &udc->ep[i];
1452 		epcfgreg = udc->read_fn(udc->addr + ep->offset);
1453 		epcfgreg &= ~XUSB_EP_CFG_STALL_MASK;
1454 		udc->write_fn(udc->addr, ep->offset, epcfgreg);
1455 		if (ep->epnumber) {
1456 			/* Reset the toggle bit.*/
1457 			epcfgreg = udc->read_fn(udc->addr + ep->offset);
1458 			epcfgreg &= ~XUSB_EP_CFG_DATA_TOGGLE_MASK;
1459 			udc->write_fn(udc->addr, ep->offset, epcfgreg);
1460 		}
1461 	}
1462 }
1463 
1464 /**
1465  * xudc_startup_handler - The usb device controller interrupt handler.
1466  * @udc: pointer to the udc structure.
1467  * @intrstatus: The mask value containing the interrupt sources.
1468  *
1469  * This function handles the RESET,SUSPEND,RESUME and DISCONNECT interrupts.
1470  */
1471 static void xudc_startup_handler(struct xusb_udc *udc, u32 intrstatus)
1472 {
1473 	u32 intrreg;
1474 
1475 	if (intrstatus & XUSB_STATUS_RESET_MASK) {
1476 
1477 		dev_dbg(udc->dev, "Reset\n");
1478 
1479 		if (intrstatus & XUSB_STATUS_HIGH_SPEED_MASK)
1480 			udc->gadget.speed = USB_SPEED_HIGH;
1481 		else
1482 			udc->gadget.speed = USB_SPEED_FULL;
1483 
1484 		xudc_stop_activity(udc);
1485 		xudc_clear_stall_all_ep(udc);
1486 		udc->write_fn(udc->addr, XUSB_TESTMODE_OFFSET, 0);
1487 
1488 		/* Set device address and remote wakeup to 0 */
1489 		udc->write_fn(udc->addr, XUSB_ADDRESS_OFFSET, 0);
1490 		udc->remote_wkp = 0;
1491 
1492 		/* Enable the suspend, resume and disconnect */
1493 		intrreg = udc->read_fn(udc->addr + XUSB_IER_OFFSET);
1494 		intrreg |= XUSB_STATUS_SUSPEND_MASK | XUSB_STATUS_RESUME_MASK |
1495 			   XUSB_STATUS_DISCONNECT_MASK;
1496 		udc->write_fn(udc->addr, XUSB_IER_OFFSET, intrreg);
1497 	}
1498 	if (intrstatus & XUSB_STATUS_SUSPEND_MASK) {
1499 
1500 		dev_dbg(udc->dev, "Suspend\n");
1501 
1502 		/* Enable the reset, resume and disconnect */
1503 		intrreg = udc->read_fn(udc->addr + XUSB_IER_OFFSET);
1504 		intrreg |= XUSB_STATUS_RESET_MASK | XUSB_STATUS_RESUME_MASK |
1505 			   XUSB_STATUS_DISCONNECT_MASK;
1506 		udc->write_fn(udc->addr, XUSB_IER_OFFSET, intrreg);
1507 
1508 		udc->usb_state = USB_STATE_SUSPENDED;
1509 
1510 		if (udc->driver->suspend) {
1511 			spin_unlock(&udc->lock);
1512 			udc->driver->suspend(&udc->gadget);
1513 			spin_lock(&udc->lock);
1514 		}
1515 	}
1516 	if (intrstatus & XUSB_STATUS_RESUME_MASK) {
1517 		bool condition = (udc->usb_state != USB_STATE_SUSPENDED);
1518 
1519 		dev_WARN_ONCE(udc->dev, condition,
1520 				"Resume IRQ while not suspended\n");
1521 
1522 		dev_dbg(udc->dev, "Resume\n");
1523 
1524 		/* Enable the reset, suspend and disconnect */
1525 		intrreg = udc->read_fn(udc->addr + XUSB_IER_OFFSET);
1526 		intrreg |= XUSB_STATUS_RESET_MASK | XUSB_STATUS_SUSPEND_MASK |
1527 			   XUSB_STATUS_DISCONNECT_MASK;
1528 		udc->write_fn(udc->addr, XUSB_IER_OFFSET, intrreg);
1529 
1530 		udc->usb_state = 0;
1531 
1532 		if (udc->driver->resume) {
1533 			spin_unlock(&udc->lock);
1534 			udc->driver->resume(&udc->gadget);
1535 			spin_lock(&udc->lock);
1536 		}
1537 	}
1538 	if (intrstatus & XUSB_STATUS_DISCONNECT_MASK) {
1539 
1540 		dev_dbg(udc->dev, "Disconnect\n");
1541 
1542 		/* Enable the reset, resume and suspend */
1543 		intrreg = udc->read_fn(udc->addr + XUSB_IER_OFFSET);
1544 		intrreg |= XUSB_STATUS_RESET_MASK | XUSB_STATUS_RESUME_MASK |
1545 			   XUSB_STATUS_SUSPEND_MASK;
1546 		udc->write_fn(udc->addr, XUSB_IER_OFFSET, intrreg);
1547 
1548 		if (udc->driver && udc->driver->disconnect) {
1549 			spin_unlock(&udc->lock);
1550 			udc->driver->disconnect(&udc->gadget);
1551 			spin_lock(&udc->lock);
1552 		}
1553 	}
1554 }
1555 
1556 /**
1557  * xudc_ep0_stall - Stall endpoint zero.
1558  * @udc: pointer to the udc structure.
1559  *
1560  * This function stalls endpoint zero.
1561  */
1562 static void xudc_ep0_stall(struct xusb_udc *udc)
1563 {
1564 	u32 epcfgreg;
1565 	struct xusb_ep *ep0 = &udc->ep[XUSB_EP_NUMBER_ZERO];
1566 
1567 	epcfgreg = udc->read_fn(udc->addr + ep0->offset);
1568 	epcfgreg |= XUSB_EP_CFG_STALL_MASK;
1569 	udc->write_fn(udc->addr, ep0->offset, epcfgreg);
1570 }
1571 
1572 /**
1573  * xudc_setaddress - executes SET_ADDRESS command
1574  * @udc: pointer to the udc structure.
1575  *
1576  * This function executes USB SET_ADDRESS command
1577  */
1578 static void xudc_setaddress(struct xusb_udc *udc)
1579 {
1580 	struct xusb_ep *ep0	= &udc->ep[0];
1581 	struct xusb_req *req	= udc->req;
1582 	int ret;
1583 
1584 	req->usb_req.length = 0;
1585 	ret = __xudc_ep0_queue(ep0, req);
1586 	if (ret == 0)
1587 		return;
1588 
1589 	dev_err(udc->dev, "Can't respond to SET ADDRESS request\n");
1590 	xudc_ep0_stall(udc);
1591 }
1592 
1593 /**
1594  * xudc_getstatus - executes GET_STATUS command
1595  * @udc: pointer to the udc structure.
1596  *
1597  * This function executes USB GET_STATUS command
1598  */
1599 static void xudc_getstatus(struct xusb_udc *udc)
1600 {
1601 	struct xusb_ep *ep0	= &udc->ep[0];
1602 	struct xusb_req *req	= udc->req;
1603 	struct xusb_ep *target_ep;
1604 	u16 status = 0;
1605 	u32 epcfgreg;
1606 	int epnum;
1607 	u32 halt;
1608 	int ret;
1609 
1610 	switch (udc->setup.bRequestType & USB_RECIP_MASK) {
1611 	case USB_RECIP_DEVICE:
1612 		/* Get device status */
1613 		status = 1 << USB_DEVICE_SELF_POWERED;
1614 		if (udc->remote_wkp)
1615 			status |= (1 << USB_DEVICE_REMOTE_WAKEUP);
1616 		break;
1617 	case USB_RECIP_INTERFACE:
1618 		break;
1619 	case USB_RECIP_ENDPOINT:
1620 		epnum = udc->setup.wIndex & USB_ENDPOINT_NUMBER_MASK;
1621 		if (epnum >= XUSB_MAX_ENDPOINTS)
1622 			goto stall;
1623 		target_ep = &udc->ep[epnum];
1624 		epcfgreg = udc->read_fn(udc->addr + target_ep->offset);
1625 		halt = epcfgreg & XUSB_EP_CFG_STALL_MASK;
1626 		if (udc->setup.wIndex & USB_DIR_IN) {
1627 			if (!target_ep->is_in)
1628 				goto stall;
1629 		} else {
1630 			if (target_ep->is_in)
1631 				goto stall;
1632 		}
1633 		if (halt)
1634 			status = 1 << USB_ENDPOINT_HALT;
1635 		break;
1636 	default:
1637 		goto stall;
1638 	}
1639 
1640 	req->usb_req.length = 2;
1641 	*(u16 *)req->usb_req.buf = cpu_to_le16(status);
1642 	ret = __xudc_ep0_queue(ep0, req);
1643 	if (ret == 0)
1644 		return;
1645 stall:
1646 	dev_err(udc->dev, "Can't respond to getstatus request\n");
1647 	xudc_ep0_stall(udc);
1648 }
1649 
1650 /**
1651  * xudc_set_clear_feature - Executes the set feature and clear feature commands.
1652  * @udc: pointer to the usb device controller structure.
1653  *
1654  * Processes the SET_FEATURE and CLEAR_FEATURE commands.
1655  */
1656 static void xudc_set_clear_feature(struct xusb_udc *udc)
1657 {
1658 	struct xusb_ep *ep0	= &udc->ep[0];
1659 	struct xusb_req *req	= udc->req;
1660 	struct xusb_ep *target_ep;
1661 	u8 endpoint;
1662 	u8 outinbit;
1663 	u32 epcfgreg;
1664 	int flag = (udc->setup.bRequest == USB_REQ_SET_FEATURE ? 1 : 0);
1665 	int ret;
1666 
1667 	switch (udc->setup.bRequestType) {
1668 	case USB_RECIP_DEVICE:
1669 		switch (udc->setup.wValue) {
1670 		case USB_DEVICE_TEST_MODE:
1671 			/*
1672 			 * The Test Mode will be executed
1673 			 * after the status phase.
1674 			 */
1675 			break;
1676 		case USB_DEVICE_REMOTE_WAKEUP:
1677 			if (flag)
1678 				udc->remote_wkp = 1;
1679 			else
1680 				udc->remote_wkp = 0;
1681 			break;
1682 		default:
1683 			xudc_ep0_stall(udc);
1684 			break;
1685 		}
1686 		break;
1687 	case USB_RECIP_ENDPOINT:
1688 		if (!udc->setup.wValue) {
1689 			endpoint = udc->setup.wIndex & USB_ENDPOINT_NUMBER_MASK;
1690 			if (endpoint >= XUSB_MAX_ENDPOINTS) {
1691 				xudc_ep0_stall(udc);
1692 				return;
1693 			}
1694 			target_ep = &udc->ep[endpoint];
1695 			outinbit = udc->setup.wIndex & USB_ENDPOINT_DIR_MASK;
1696 			outinbit = outinbit >> 7;
1697 
1698 			/* Make sure direction matches.*/
1699 			if (outinbit != target_ep->is_in) {
1700 				xudc_ep0_stall(udc);
1701 				return;
1702 			}
1703 			epcfgreg = udc->read_fn(udc->addr + target_ep->offset);
1704 			if (!endpoint) {
1705 				/* Clear the stall.*/
1706 				epcfgreg &= ~XUSB_EP_CFG_STALL_MASK;
1707 				udc->write_fn(udc->addr,
1708 					      target_ep->offset, epcfgreg);
1709 			} else {
1710 				if (flag) {
1711 					epcfgreg |= XUSB_EP_CFG_STALL_MASK;
1712 					udc->write_fn(udc->addr,
1713 						      target_ep->offset,
1714 						      epcfgreg);
1715 				} else {
1716 					/* Unstall the endpoint.*/
1717 					epcfgreg &= ~(XUSB_EP_CFG_STALL_MASK |
1718 						XUSB_EP_CFG_DATA_TOGGLE_MASK);
1719 					udc->write_fn(udc->addr,
1720 						      target_ep->offset,
1721 						      epcfgreg);
1722 				}
1723 			}
1724 		}
1725 		break;
1726 	default:
1727 		xudc_ep0_stall(udc);
1728 		return;
1729 	}
1730 
1731 	req->usb_req.length = 0;
1732 	ret = __xudc_ep0_queue(ep0, req);
1733 	if (ret == 0)
1734 		return;
1735 
1736 	dev_err(udc->dev, "Can't respond to SET/CLEAR FEATURE\n");
1737 	xudc_ep0_stall(udc);
1738 }
1739 
1740 /**
1741  * xudc_handle_setup - Processes the setup packet.
1742  * @udc: pointer to the usb device controller structure.
1743  *
1744  * Process setup packet and delegate to gadget layer.
1745  */
1746 static void xudc_handle_setup(struct xusb_udc *udc)
1747 	__must_hold(&udc->lock)
1748 {
1749 	struct xusb_ep *ep0 = &udc->ep[0];
1750 	struct usb_ctrlrequest setup;
1751 	u32 *ep0rambase;
1752 
1753 	/* Load up the chapter 9 command buffer.*/
1754 	ep0rambase = (u32 __force *) (udc->addr + XUSB_SETUP_PKT_ADDR_OFFSET);
1755 	memcpy(&setup, ep0rambase, 8);
1756 
1757 	udc->setup = setup;
1758 	udc->setup.wValue = cpu_to_le16(setup.wValue);
1759 	udc->setup.wIndex = cpu_to_le16(setup.wIndex);
1760 	udc->setup.wLength = cpu_to_le16(setup.wLength);
1761 
1762 	/* Clear previous requests */
1763 	xudc_nuke(ep0, -ECONNRESET);
1764 
1765 	if (udc->setup.bRequestType & USB_DIR_IN) {
1766 		/* Execute the get command.*/
1767 		udc->setupseqrx = STATUS_PHASE;
1768 		udc->setupseqtx = DATA_PHASE;
1769 	} else {
1770 		/* Execute the put command.*/
1771 		udc->setupseqrx = DATA_PHASE;
1772 		udc->setupseqtx = STATUS_PHASE;
1773 	}
1774 
1775 	switch (udc->setup.bRequest) {
1776 	case USB_REQ_GET_STATUS:
1777 		/* Data+Status phase form udc */
1778 		if ((udc->setup.bRequestType &
1779 				(USB_DIR_IN | USB_TYPE_MASK)) !=
1780 				(USB_DIR_IN | USB_TYPE_STANDARD))
1781 			break;
1782 		xudc_getstatus(udc);
1783 		return;
1784 	case USB_REQ_SET_ADDRESS:
1785 		/* Status phase from udc */
1786 		if (udc->setup.bRequestType != (USB_DIR_OUT |
1787 				USB_TYPE_STANDARD | USB_RECIP_DEVICE))
1788 			break;
1789 		xudc_setaddress(udc);
1790 		return;
1791 	case USB_REQ_CLEAR_FEATURE:
1792 	case USB_REQ_SET_FEATURE:
1793 		/* Requests with no data phase, status phase from udc */
1794 		if ((udc->setup.bRequestType & USB_TYPE_MASK)
1795 				!= USB_TYPE_STANDARD)
1796 			break;
1797 		xudc_set_clear_feature(udc);
1798 		return;
1799 	default:
1800 		break;
1801 	}
1802 
1803 	spin_unlock(&udc->lock);
1804 	if (udc->driver->setup(&udc->gadget, &setup) < 0)
1805 		xudc_ep0_stall(udc);
1806 	spin_lock(&udc->lock);
1807 }
1808 
1809 /**
1810  * xudc_ep0_out - Processes the endpoint 0 OUT token.
1811  * @udc: pointer to the usb device controller structure.
1812  */
1813 static void xudc_ep0_out(struct xusb_udc *udc)
1814 {
1815 	struct xusb_ep *ep0 = &udc->ep[0];
1816 	struct xusb_req *req;
1817 	u8 *ep0rambase;
1818 	unsigned int bytes_to_rx;
1819 	void *buffer;
1820 
1821 	req = list_first_entry(&ep0->queue, struct xusb_req, queue);
1822 
1823 	switch (udc->setupseqrx) {
1824 	case STATUS_PHASE:
1825 		/*
1826 		 * This resets both state machines for the next
1827 		 * Setup packet.
1828 		 */
1829 		udc->setupseqrx = SETUP_PHASE;
1830 		udc->setupseqtx = SETUP_PHASE;
1831 		req->usb_req.actual = req->usb_req.length;
1832 		xudc_done(ep0, req, 0);
1833 		break;
1834 	case DATA_PHASE:
1835 		bytes_to_rx = udc->read_fn(udc->addr +
1836 					   XUSB_EP_BUF0COUNT_OFFSET);
1837 		/* Copy the data to be received from the DPRAM. */
1838 		ep0rambase = (u8 __force *) (udc->addr +
1839 			     (ep0->rambase << 2));
1840 		buffer = req->usb_req.buf + req->usb_req.actual;
1841 		req->usb_req.actual = req->usb_req.actual + bytes_to_rx;
1842 		memcpy(buffer, ep0rambase, bytes_to_rx);
1843 
1844 		if (req->usb_req.length == req->usb_req.actual) {
1845 			/* Data transfer completed get ready for Status stage */
1846 			xudc_wrstatus(udc);
1847 		} else {
1848 			/* Enable EP0 buffer to receive data */
1849 			udc->write_fn(udc->addr, XUSB_EP_BUF0COUNT_OFFSET, 0);
1850 			udc->write_fn(udc->addr, XUSB_BUFFREADY_OFFSET, 1);
1851 		}
1852 		break;
1853 	default:
1854 		break;
1855 	}
1856 }
1857 
1858 /**
1859  * xudc_ep0_in - Processes the endpoint 0 IN token.
1860  * @udc: pointer to the usb device controller structure.
1861  */
1862 static void xudc_ep0_in(struct xusb_udc *udc)
1863 {
1864 	struct xusb_ep *ep0 = &udc->ep[0];
1865 	struct xusb_req *req;
1866 	unsigned int bytes_to_tx;
1867 	void *buffer;
1868 	u32 epcfgreg;
1869 	u16 count = 0;
1870 	u16 length;
1871 	u8 *ep0rambase;
1872 	u8 test_mode = udc->setup.wIndex >> 8;
1873 
1874 	req = list_first_entry(&ep0->queue, struct xusb_req, queue);
1875 	bytes_to_tx = req->usb_req.length - req->usb_req.actual;
1876 
1877 	switch (udc->setupseqtx) {
1878 	case STATUS_PHASE:
1879 		switch (udc->setup.bRequest) {
1880 		case USB_REQ_SET_ADDRESS:
1881 			/* Set the address of the device.*/
1882 			udc->write_fn(udc->addr, XUSB_ADDRESS_OFFSET,
1883 				      udc->setup.wValue);
1884 			break;
1885 		case USB_REQ_SET_FEATURE:
1886 			if (udc->setup.bRequestType ==
1887 					USB_RECIP_DEVICE) {
1888 				if (udc->setup.wValue ==
1889 						USB_DEVICE_TEST_MODE)
1890 					udc->write_fn(udc->addr,
1891 						      XUSB_TESTMODE_OFFSET,
1892 						      test_mode);
1893 			}
1894 			break;
1895 		}
1896 		req->usb_req.actual = req->usb_req.length;
1897 		xudc_done(ep0, req, 0);
1898 		break;
1899 	case DATA_PHASE:
1900 		if (!bytes_to_tx) {
1901 			/*
1902 			 * We're done with data transfer, next
1903 			 * will be zero length OUT with data toggle of
1904 			 * 1. Setup data_toggle.
1905 			 */
1906 			epcfgreg = udc->read_fn(udc->addr + ep0->offset);
1907 			epcfgreg |= XUSB_EP_CFG_DATA_TOGGLE_MASK;
1908 			udc->write_fn(udc->addr, ep0->offset, epcfgreg);
1909 			udc->setupseqtx = STATUS_PHASE;
1910 		} else {
1911 			length = count = min_t(u32, bytes_to_tx,
1912 					       EP0_MAX_PACKET);
1913 			/* Copy the data to be transmitted into the DPRAM. */
1914 			ep0rambase = (u8 __force *) (udc->addr +
1915 				     (ep0->rambase << 2));
1916 			buffer = req->usb_req.buf + req->usb_req.actual;
1917 			req->usb_req.actual = req->usb_req.actual + length;
1918 			memcpy(ep0rambase, buffer, length);
1919 		}
1920 		udc->write_fn(udc->addr, XUSB_EP_BUF0COUNT_OFFSET, count);
1921 		udc->write_fn(udc->addr, XUSB_BUFFREADY_OFFSET, 1);
1922 		break;
1923 	default:
1924 		break;
1925 	}
1926 }
1927 
1928 /**
1929  * xudc_ctrl_ep_handler - Endpoint 0 interrupt handler.
1930  * @udc: pointer to the udc structure.
1931  * @intrstatus:	It's the mask value for the interrupt sources on endpoint 0.
1932  *
1933  * Processes the commands received during enumeration phase.
1934  */
1935 static void xudc_ctrl_ep_handler(struct xusb_udc *udc, u32 intrstatus)
1936 {
1937 
1938 	if (intrstatus & XUSB_STATUS_SETUP_PACKET_MASK) {
1939 		xudc_handle_setup(udc);
1940 	} else {
1941 		if (intrstatus & XUSB_STATUS_FIFO_BUFF_RDY_MASK)
1942 			xudc_ep0_out(udc);
1943 		else if (intrstatus & XUSB_STATUS_FIFO_BUFF_FREE_MASK)
1944 			xudc_ep0_in(udc);
1945 	}
1946 }
1947 
1948 /**
1949  * xudc_nonctrl_ep_handler - Non control endpoint interrupt handler.
1950  * @udc: pointer to the udc structure.
1951  * @epnum: End point number for which the interrupt is to be processed
1952  * @intrstatus:	mask value for interrupt sources of endpoints other
1953  *		than endpoint 0.
1954  *
1955  * Processes the buffer completion interrupts.
1956  */
1957 static void xudc_nonctrl_ep_handler(struct xusb_udc *udc, u8 epnum,
1958 				    u32 intrstatus)
1959 {
1960 
1961 	struct xusb_req *req;
1962 	struct xusb_ep *ep;
1963 
1964 	ep = &udc->ep[epnum];
1965 	/* Process the End point interrupts.*/
1966 	if (intrstatus & (XUSB_STATUS_EP0_BUFF1_COMP_MASK << epnum))
1967 		ep->buffer0ready = 0;
1968 	if (intrstatus & (XUSB_STATUS_EP0_BUFF2_COMP_MASK << epnum))
1969 		ep->buffer1ready = false;
1970 
1971 	if (list_empty(&ep->queue))
1972 		return;
1973 
1974 	req = list_first_entry(&ep->queue, struct xusb_req, queue);
1975 
1976 	if (ep->is_in)
1977 		xudc_write_fifo(ep, req);
1978 	else
1979 		xudc_read_fifo(ep, req);
1980 }
1981 
1982 /**
1983  * xudc_irq - The main interrupt handler.
1984  * @irq: The interrupt number.
1985  * @_udc: pointer to the usb device controller structure.
1986  *
1987  * Return: IRQ_HANDLED after the interrupt is handled.
1988  */
1989 static irqreturn_t xudc_irq(int irq, void *_udc)
1990 {
1991 	struct xusb_udc *udc = _udc;
1992 	u32 intrstatus;
1993 	u32 ier;
1994 	u8 index;
1995 	u32 bufintr;
1996 	unsigned long flags;
1997 
1998 	spin_lock_irqsave(&udc->lock, flags);
1999 
2000 	/*
2001 	 * Event interrupts are level sensitive hence first disable
2002 	 * IER, read ISR and figure out active interrupts.
2003 	 */
2004 	ier = udc->read_fn(udc->addr + XUSB_IER_OFFSET);
2005 	ier &= ~XUSB_STATUS_INTR_EVENT_MASK;
2006 	udc->write_fn(udc->addr, XUSB_IER_OFFSET, ier);
2007 
2008 	/* Read the Interrupt Status Register.*/
2009 	intrstatus = udc->read_fn(udc->addr + XUSB_STATUS_OFFSET);
2010 
2011 	/* Call the handler for the event interrupt.*/
2012 	if (intrstatus & XUSB_STATUS_INTR_EVENT_MASK) {
2013 		/*
2014 		 * Check if there is any action to be done for :
2015 		 * - USB Reset received {XUSB_STATUS_RESET_MASK}
2016 		 * - USB Suspend received {XUSB_STATUS_SUSPEND_MASK}
2017 		 * - USB Resume received {XUSB_STATUS_RESUME_MASK}
2018 		 * - USB Disconnect received {XUSB_STATUS_DISCONNECT_MASK}
2019 		 */
2020 		xudc_startup_handler(udc, intrstatus);
2021 	}
2022 
2023 	/* Check the buffer completion interrupts */
2024 	if (intrstatus & XUSB_STATUS_INTR_BUFF_COMP_ALL_MASK) {
2025 		/* Enable Reset, Suspend, Resume and Disconnect  */
2026 		ier = udc->read_fn(udc->addr + XUSB_IER_OFFSET);
2027 		ier |= XUSB_STATUS_INTR_EVENT_MASK;
2028 		udc->write_fn(udc->addr, XUSB_IER_OFFSET, ier);
2029 
2030 		if (intrstatus & XUSB_STATUS_EP0_BUFF1_COMP_MASK)
2031 			xudc_ctrl_ep_handler(udc, intrstatus);
2032 
2033 		for (index = 1; index < 8; index++) {
2034 			bufintr = ((intrstatus &
2035 				  (XUSB_STATUS_EP1_BUFF1_COMP_MASK <<
2036 				  (index - 1))) || (intrstatus &
2037 				  (XUSB_STATUS_EP1_BUFF2_COMP_MASK <<
2038 				  (index - 1))));
2039 			if (bufintr) {
2040 				xudc_nonctrl_ep_handler(udc, index,
2041 							intrstatus);
2042 			}
2043 		}
2044 	}
2045 
2046 	spin_unlock_irqrestore(&udc->lock, flags);
2047 	return IRQ_HANDLED;
2048 }
2049 
2050 /**
2051  * xudc_probe - The device probe function for driver initialization.
2052  * @pdev: pointer to the platform device structure.
2053  *
2054  * Return: 0 for success and error value on failure
2055  */
2056 static int xudc_probe(struct platform_device *pdev)
2057 {
2058 	struct device_node *np = pdev->dev.of_node;
2059 	struct resource *res;
2060 	struct xusb_udc *udc;
2061 	int irq;
2062 	int ret;
2063 	u32 ier;
2064 	u8 *buff;
2065 
2066 	udc = devm_kzalloc(&pdev->dev, sizeof(*udc), GFP_KERNEL);
2067 	if (!udc)
2068 		return -ENOMEM;
2069 
2070 	/* Create a dummy request for GET_STATUS, SET_ADDRESS */
2071 	udc->req = devm_kzalloc(&pdev->dev, sizeof(struct xusb_req),
2072 				GFP_KERNEL);
2073 	if (!udc->req)
2074 		return -ENOMEM;
2075 
2076 	buff = devm_kzalloc(&pdev->dev, STATUSBUFF_SIZE, GFP_KERNEL);
2077 	if (!buff)
2078 		return -ENOMEM;
2079 
2080 	udc->req->usb_req.buf = buff;
2081 
2082 	/* Map the registers */
2083 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
2084 	udc->addr = devm_ioremap_resource(&pdev->dev, res);
2085 	if (IS_ERR(udc->addr))
2086 		return PTR_ERR(udc->addr);
2087 
2088 	irq = platform_get_irq(pdev, 0);
2089 	if (irq < 0)
2090 		return irq;
2091 	ret = devm_request_irq(&pdev->dev, irq, xudc_irq, 0,
2092 			       dev_name(&pdev->dev), udc);
2093 	if (ret < 0) {
2094 		dev_dbg(&pdev->dev, "unable to request irq %d", irq);
2095 		goto fail;
2096 	}
2097 
2098 	udc->dma_enabled = of_property_read_bool(np, "xlnx,has-builtin-dma");
2099 
2100 	/* Setup gadget structure */
2101 	udc->gadget.ops = &xusb_udc_ops;
2102 	udc->gadget.max_speed = USB_SPEED_HIGH;
2103 	udc->gadget.speed = USB_SPEED_UNKNOWN;
2104 	udc->gadget.ep0 = &udc->ep[XUSB_EP_NUMBER_ZERO].ep_usb;
2105 	udc->gadget.name = driver_name;
2106 
2107 	udc->clk = devm_clk_get(&pdev->dev, "s_axi_aclk");
2108 	if (IS_ERR(udc->clk)) {
2109 		if (PTR_ERR(udc->clk) != -ENOENT) {
2110 			ret = PTR_ERR(udc->clk);
2111 			goto fail;
2112 		}
2113 
2114 		/*
2115 		 * Clock framework support is optional, continue on,
2116 		 * anyways if we don't find a matching clock
2117 		 */
2118 		dev_warn(&pdev->dev, "s_axi_aclk clock property is not found\n");
2119 		udc->clk = NULL;
2120 	}
2121 
2122 	ret = clk_prepare_enable(udc->clk);
2123 	if (ret) {
2124 		dev_err(&pdev->dev, "Unable to enable clock.\n");
2125 		return ret;
2126 	}
2127 
2128 	spin_lock_init(&udc->lock);
2129 
2130 	/* Check for IP endianness */
2131 	udc->write_fn = xudc_write32_be;
2132 	udc->read_fn = xudc_read32_be;
2133 	udc->write_fn(udc->addr, XUSB_TESTMODE_OFFSET, USB_TEST_J);
2134 	if ((udc->read_fn(udc->addr + XUSB_TESTMODE_OFFSET))
2135 			!= USB_TEST_J) {
2136 		udc->write_fn = xudc_write32;
2137 		udc->read_fn = xudc_read32;
2138 	}
2139 	udc->write_fn(udc->addr, XUSB_TESTMODE_OFFSET, 0);
2140 
2141 	xudc_eps_init(udc);
2142 
2143 	/* Set device address to 0.*/
2144 	udc->write_fn(udc->addr, XUSB_ADDRESS_OFFSET, 0);
2145 
2146 	ret = usb_add_gadget_udc(&pdev->dev, &udc->gadget);
2147 	if (ret)
2148 		goto err_disable_unprepare_clk;
2149 
2150 	udc->dev = &udc->gadget.dev;
2151 
2152 	/* Enable the interrupts.*/
2153 	ier = XUSB_STATUS_GLOBAL_INTR_MASK | XUSB_STATUS_INTR_EVENT_MASK |
2154 	      XUSB_STATUS_FIFO_BUFF_RDY_MASK | XUSB_STATUS_FIFO_BUFF_FREE_MASK |
2155 	      XUSB_STATUS_SETUP_PACKET_MASK |
2156 	      XUSB_STATUS_INTR_BUFF_COMP_ALL_MASK;
2157 
2158 	udc->write_fn(udc->addr, XUSB_IER_OFFSET, ier);
2159 
2160 	platform_set_drvdata(pdev, udc);
2161 
2162 	dev_vdbg(&pdev->dev, "%s at 0x%08X mapped to %p %s\n",
2163 		 driver_name, (u32)res->start, udc->addr,
2164 		 udc->dma_enabled ? "with DMA" : "without DMA");
2165 
2166 	return 0;
2167 
2168 err_disable_unprepare_clk:
2169 	clk_disable_unprepare(udc->clk);
2170 fail:
2171 	dev_err(&pdev->dev, "probe failed, %d\n", ret);
2172 	return ret;
2173 }
2174 
2175 /**
2176  * xudc_remove - Releases the resources allocated during the initialization.
2177  * @pdev: pointer to the platform device structure.
2178  *
2179  * Return: 0 always
2180  */
2181 static void xudc_remove(struct platform_device *pdev)
2182 {
2183 	struct xusb_udc *udc = platform_get_drvdata(pdev);
2184 
2185 	usb_del_gadget_udc(&udc->gadget);
2186 	clk_disable_unprepare(udc->clk);
2187 }
2188 
2189 #ifdef CONFIG_PM_SLEEP
2190 static int xudc_suspend(struct device *dev)
2191 {
2192 	struct xusb_udc *udc;
2193 	u32 crtlreg;
2194 	unsigned long flags;
2195 
2196 	udc = dev_get_drvdata(dev);
2197 
2198 	spin_lock_irqsave(&udc->lock, flags);
2199 
2200 	crtlreg = udc->read_fn(udc->addr + XUSB_CONTROL_OFFSET);
2201 	crtlreg &= ~XUSB_CONTROL_USB_READY_MASK;
2202 
2203 	udc->write_fn(udc->addr, XUSB_CONTROL_OFFSET, crtlreg);
2204 
2205 	spin_unlock_irqrestore(&udc->lock, flags);
2206 	if (udc->driver && udc->driver->suspend)
2207 		udc->driver->suspend(&udc->gadget);
2208 
2209 	clk_disable(udc->clk);
2210 
2211 	return 0;
2212 }
2213 
2214 static int xudc_resume(struct device *dev)
2215 {
2216 	struct xusb_udc *udc;
2217 	u32 crtlreg;
2218 	unsigned long flags;
2219 	int ret;
2220 
2221 	udc = dev_get_drvdata(dev);
2222 
2223 	ret = clk_enable(udc->clk);
2224 	if (ret < 0)
2225 		return ret;
2226 
2227 	spin_lock_irqsave(&udc->lock, flags);
2228 
2229 	crtlreg = udc->read_fn(udc->addr + XUSB_CONTROL_OFFSET);
2230 	crtlreg |= XUSB_CONTROL_USB_READY_MASK;
2231 
2232 	udc->write_fn(udc->addr, XUSB_CONTROL_OFFSET, crtlreg);
2233 
2234 	spin_unlock_irqrestore(&udc->lock, flags);
2235 
2236 	return 0;
2237 }
2238 #endif /* CONFIG_PM_SLEEP */
2239 
2240 static const struct dev_pm_ops xudc_pm_ops = {
2241 	SET_SYSTEM_SLEEP_PM_OPS(xudc_suspend, xudc_resume)
2242 };
2243 
2244 /* Match table for of_platform binding */
2245 static const struct of_device_id usb_of_match[] = {
2246 	{ .compatible = "xlnx,usb2-device-4.00.a", },
2247 	{ /* end of list */ },
2248 };
2249 MODULE_DEVICE_TABLE(of, usb_of_match);
2250 
2251 static struct platform_driver xudc_driver = {
2252 	.driver = {
2253 		.name = driver_name,
2254 		.of_match_table = usb_of_match,
2255 		.pm	= &xudc_pm_ops,
2256 	},
2257 	.probe = xudc_probe,
2258 	.remove_new = xudc_remove,
2259 };
2260 
2261 module_platform_driver(xudc_driver);
2262 
2263 MODULE_DESCRIPTION("Xilinx udc driver");
2264 MODULE_AUTHOR("Xilinx, Inc");
2265 MODULE_LICENSE("GPL");
2266