1/*
2 * Simple synchronous serial port driver for ETRAX FS and ARTPEC-3.
3 *
4 * Copyright (c) 2005, 2008 Axis Communications AB
5 * Author: Mikael Starvik
6 *
7 */
8
9#include <linux/module.h>
10#include <linux/kernel.h>
11#include <linux/types.h>
12#include <linux/errno.h>
13#include <linux/major.h>
14#include <linux/sched.h>
15#include <linux/mutex.h>
16#include <linux/interrupt.h>
17#include <linux/poll.h>
18#include <linux/fs.h>
19#include <linux/cdev.h>
20#include <linux/device.h>
21#include <linux/wait.h>
22
23#include <asm/io.h>
24#include <mach/dma.h>
25#include <pinmux.h>
26#include <hwregs/reg_rdwr.h>
27#include <hwregs/sser_defs.h>
28#include <hwregs/timer_defs.h>
29#include <hwregs/dma_defs.h>
30#include <hwregs/dma.h>
31#include <hwregs/intr_vect_defs.h>
32#include <hwregs/intr_vect.h>
33#include <hwregs/reg_map.h>
34#include <asm/sync_serial.h>
35
36
37/* The receiver is a bit tricky because of the continuous stream of data.*/
38/*                                                                       */
39/* Three DMA descriptors are linked together. Each DMA descriptor is     */
40/* responsible for port->bufchunk of a common buffer.                    */
41/*                                                                       */
42/* +---------------------------------------------+                       */
43/* |   +----------+   +----------+   +----------+ |                      */
44/* +-> | Descr[0] |-->| Descr[1] |-->| Descr[2] |-+                      */
45/*     +----------+   +----------+   +----------+                        */
46/*         |            |              |                                 */
47/*         v            v              v                                 */
48/*   +-------------------------------------+                             */
49/*   |        BUFFER                       |                             */
50/*   +-------------------------------------+                             */
51/*      |<- data_avail ->|                                               */
52/*    readp          writep                                              */
53/*                                                                       */
54/* If the application keeps up the pace readp will be right after writep.*/
55/* If the application can't keep the pace we have to throw away data.    */
56/* The idea is that readp should be ready with the data pointed out by	 */
57/* Descr[i] when the DMA has filled in Descr[i+1].                       */
58/* Otherwise we will discard	                                         */
59/* the rest of the data pointed out by Descr1 and set readp to the start */
60/* of Descr2                                                             */
61
62/* IN_BUFFER_SIZE should be a multiple of 6 to make sure that 24 bit */
63/* words can be handled */
64#define IN_DESCR_SIZE SSP_INPUT_CHUNK_SIZE
65#define NBR_IN_DESCR (8*6)
66#define IN_BUFFER_SIZE (IN_DESCR_SIZE * NBR_IN_DESCR)
67
68#define NBR_OUT_DESCR 8
69#define OUT_BUFFER_SIZE (1024 * NBR_OUT_DESCR)
70
71#define DEFAULT_FRAME_RATE 0
72#define DEFAULT_WORD_RATE 7
73
74/* To be removed when we move to pure udev. */
75#define SYNC_SERIAL_MAJOR 125
76
77/* NOTE: Enabling some debug will likely cause overrun or underrun,
78 * especially if manual mode is used.
79 */
80#define DEBUG(x)
81#define DEBUGREAD(x)
82#define DEBUGWRITE(x)
83#define DEBUGPOLL(x)
84#define DEBUGRXINT(x)
85#define DEBUGTXINT(x)
86#define DEBUGTRDMA(x)
87#define DEBUGOUTBUF(x)
88
89enum syncser_irq_setup {
90	no_irq_setup = 0,
91	dma_irq_setup = 1,
92	manual_irq_setup = 2,
93};
94
95struct sync_port {
96	unsigned long regi_sser;
97	unsigned long regi_dmain;
98	unsigned long regi_dmaout;
99
100	/* Interrupt vectors. */
101	unsigned long dma_in_intr_vect; /* Used for DMA in. */
102	unsigned long dma_out_intr_vect; /* Used for DMA out. */
103	unsigned long syncser_intr_vect; /* Used when no DMA. */
104
105	/* DMA number for in and out. */
106	unsigned int dma_in_nbr;
107	unsigned int dma_out_nbr;
108
109	/* DMA owner. */
110	enum dma_owner req_dma;
111
112	char started; /* 1 if port has been started */
113	char port_nbr; /* Port 0 or 1 */
114	char busy; /* 1 if port is busy */
115
116	char enabled;  /* 1 if port is enabled */
117	char use_dma;  /* 1 if port uses dma */
118	char tr_running;
119
120	enum syncser_irq_setup init_irqs;
121	int output;
122	int input;
123
124	/* Next byte to be read by application */
125	unsigned char *readp;
126	/* Next byte to be written by etrax */
127	unsigned char *writep;
128
129	unsigned int in_buffer_size;
130	unsigned int in_buffer_len;
131	unsigned int inbufchunk;
132	/* Data buffers for in and output. */
133	unsigned char out_buffer[OUT_BUFFER_SIZE] __aligned(32);
134	unsigned char in_buffer[IN_BUFFER_SIZE] __aligned(32);
135	unsigned char flip[IN_BUFFER_SIZE] __aligned(32);
136	struct timespec timestamp[NBR_IN_DESCR];
137	struct dma_descr_data *next_rx_desc;
138	struct dma_descr_data *prev_rx_desc;
139
140	struct timeval last_timestamp;
141	int read_ts_idx;
142	int write_ts_idx;
143
144	/* Pointer to the first available descriptor in the ring,
145	 * unless active_tr_descr == catch_tr_descr and a dma
146	 * transfer is active */
147	struct dma_descr_data *active_tr_descr;
148
149	/* Pointer to the first allocated descriptor in the ring */
150	struct dma_descr_data *catch_tr_descr;
151
152	/* Pointer to the descriptor with the current end-of-list */
153	struct dma_descr_data *prev_tr_descr;
154	int full;
155
156	/* Pointer to the first byte being read by DMA
157	 * or current position in out_buffer if not using DMA. */
158	unsigned char *out_rd_ptr;
159
160	/* Number of bytes currently locked for being read by DMA */
161	int out_buf_count;
162
163	dma_descr_context in_context __aligned(32);
164	dma_descr_context out_context __aligned(32);
165	dma_descr_data in_descr[NBR_IN_DESCR] __aligned(16);
166	dma_descr_data out_descr[NBR_OUT_DESCR] __aligned(16);
167
168	wait_queue_head_t out_wait_q;
169	wait_queue_head_t in_wait_q;
170
171	spinlock_t lock;
172};
173
174static DEFINE_MUTEX(sync_serial_mutex);
175static int etrax_sync_serial_init(void);
176static void initialize_port(int portnbr);
177static inline int sync_data_avail(struct sync_port *port);
178
179static int sync_serial_open(struct inode *, struct file *);
180static int sync_serial_release(struct inode *, struct file *);
181static unsigned int sync_serial_poll(struct file *filp, poll_table *wait);
182
183static long sync_serial_ioctl(struct file *file,
184			      unsigned int cmd, unsigned long arg);
185static int sync_serial_ioctl_unlocked(struct file *file,
186				      unsigned int cmd, unsigned long arg);
187static ssize_t sync_serial_write(struct file *file, const char __user *buf,
188				 size_t count, loff_t *ppos);
189static ssize_t sync_serial_read(struct file *file, char __user *buf,
190				size_t count, loff_t *ppos);
191
192#if ((defined(CONFIG_ETRAX_SYNCHRONOUS_SERIAL_PORT0) && \
193	defined(CONFIG_ETRAX_SYNCHRONOUS_SERIAL0_DMA)) || \
194	(defined(CONFIG_ETRAX_SYNCHRONOUS_SERIAL_PORT1) && \
195	defined(CONFIG_ETRAX_SYNCHRONOUS_SERIAL1_DMA)))
196#define SYNC_SER_DMA
197#else
198#define SYNC_SER_MANUAL
199#endif
200
201#ifdef SYNC_SER_DMA
202static void start_dma_out(struct sync_port *port, const char *data, int count);
203static void start_dma_in(struct sync_port *port);
204static irqreturn_t tr_interrupt(int irq, void *dev_id);
205static irqreturn_t rx_interrupt(int irq, void *dev_id);
206#endif
207#ifdef SYNC_SER_MANUAL
208static void send_word(struct sync_port *port);
209static irqreturn_t manual_interrupt(int irq, void *dev_id);
210#endif
211
212#define artpec_pinmux_alloc_fixed crisv32_pinmux_alloc_fixed
213#define artpec_request_dma crisv32_request_dma
214#define artpec_free_dma crisv32_free_dma
215
216#ifdef CONFIG_ETRAXFS
217/* ETRAX FS */
218#define DMA_OUT_NBR0		SYNC_SER0_TX_DMA_NBR
219#define DMA_IN_NBR0		SYNC_SER0_RX_DMA_NBR
220#define DMA_OUT_NBR1		SYNC_SER1_TX_DMA_NBR
221#define DMA_IN_NBR1		SYNC_SER1_RX_DMA_NBR
222#define PINMUX_SSER0		pinmux_sser0
223#define PINMUX_SSER1		pinmux_sser1
224#define SYNCSER_INST0		regi_sser0
225#define SYNCSER_INST1		regi_sser1
226#define SYNCSER_INTR_VECT0	SSER0_INTR_VECT
227#define SYNCSER_INTR_VECT1	SSER1_INTR_VECT
228#define OUT_DMA_INST0		regi_dma4
229#define IN_DMA_INST0		regi_dma5
230#define DMA_OUT_INTR_VECT0	DMA4_INTR_VECT
231#define DMA_OUT_INTR_VECT1	DMA7_INTR_VECT
232#define DMA_IN_INTR_VECT0	DMA5_INTR_VECT
233#define DMA_IN_INTR_VECT1	DMA6_INTR_VECT
234#define REQ_DMA_SYNCSER0	dma_sser0
235#define REQ_DMA_SYNCSER1	dma_sser1
236#if defined(CONFIG_ETRAX_SYNCHRONOUS_SERIAL1_DMA)
237#define PORT1_DMA 1
238#else
239#define PORT1_DMA 0
240#endif
241#elif defined(CONFIG_CRIS_MACH_ARTPEC3)
242/* ARTPEC-3 */
243#define DMA_OUT_NBR0		SYNC_SER_TX_DMA_NBR
244#define DMA_IN_NBR0		SYNC_SER_RX_DMA_NBR
245#define PINMUX_SSER0		pinmux_sser
246#define SYNCSER_INST0		regi_sser
247#define SYNCSER_INTR_VECT0	SSER_INTR_VECT
248#define OUT_DMA_INST0		regi_dma6
249#define IN_DMA_INST0		regi_dma7
250#define DMA_OUT_INTR_VECT0	DMA6_INTR_VECT
251#define DMA_IN_INTR_VECT0	DMA7_INTR_VECT
252#define REQ_DMA_SYNCSER0	dma_sser
253#define REQ_DMA_SYNCSER1	dma_sser
254#endif
255
256#if defined(CONFIG_ETRAX_SYNCHRONOUS_SERIAL0_DMA)
257#define PORT0_DMA 1
258#else
259#define PORT0_DMA 0
260#endif
261
262/* The ports */
263static struct sync_port ports[] = {
264	{
265		.regi_sser		= SYNCSER_INST0,
266		.regi_dmaout		= OUT_DMA_INST0,
267		.regi_dmain		= IN_DMA_INST0,
268		.use_dma		= PORT0_DMA,
269		.dma_in_intr_vect	= DMA_IN_INTR_VECT0,
270		.dma_out_intr_vect	= DMA_OUT_INTR_VECT0,
271		.dma_in_nbr		= DMA_IN_NBR0,
272		.dma_out_nbr		= DMA_OUT_NBR0,
273		.req_dma		= REQ_DMA_SYNCSER0,
274		.syncser_intr_vect	= SYNCSER_INTR_VECT0,
275	},
276#ifdef CONFIG_ETRAXFS
277	{
278		.regi_sser		= SYNCSER_INST1,
279		.regi_dmaout		= regi_dma6,
280		.regi_dmain		= regi_dma7,
281		.use_dma		= PORT1_DMA,
282		.dma_in_intr_vect	= DMA_IN_INTR_VECT1,
283		.dma_out_intr_vect	= DMA_OUT_INTR_VECT1,
284		.dma_in_nbr		= DMA_IN_NBR1,
285		.dma_out_nbr		= DMA_OUT_NBR1,
286		.req_dma		= REQ_DMA_SYNCSER1,
287		.syncser_intr_vect	= SYNCSER_INTR_VECT1,
288	},
289#endif
290};
291
292#define NBR_PORTS ARRAY_SIZE(ports)
293
294static const struct file_operations syncser_fops = {
295	.owner		= THIS_MODULE,
296	.write		= sync_serial_write,
297	.read		= sync_serial_read,
298	.poll		= sync_serial_poll,
299	.unlocked_ioctl	= sync_serial_ioctl,
300	.open		= sync_serial_open,
301	.release	= sync_serial_release,
302	.llseek		= noop_llseek,
303};
304
305static dev_t syncser_first;
306static int minor_count = NBR_PORTS;
307#define SYNCSER_NAME "syncser"
308static struct cdev *syncser_cdev;
309static struct class *syncser_class;
310
311static void sync_serial_start_port(struct sync_port *port)
312{
313	reg_sser_rw_cfg cfg = REG_RD(sser, port->regi_sser, rw_cfg);
314	reg_sser_rw_tr_cfg tr_cfg =
315		REG_RD(sser, port->regi_sser, rw_tr_cfg);
316	reg_sser_rw_rec_cfg rec_cfg =
317		REG_RD(sser, port->regi_sser, rw_rec_cfg);
318	cfg.en = regk_sser_yes;
319	tr_cfg.tr_en = regk_sser_yes;
320	rec_cfg.rec_en = regk_sser_yes;
321	REG_WR(sser, port->regi_sser, rw_cfg, cfg);
322	REG_WR(sser, port->regi_sser, rw_tr_cfg, tr_cfg);
323	REG_WR(sser, port->regi_sser, rw_rec_cfg, rec_cfg);
324	port->started = 1;
325}
326
327static void __init initialize_port(int portnbr)
328{
329	struct sync_port *port = &ports[portnbr];
330	reg_sser_rw_cfg cfg = { 0 };
331	reg_sser_rw_frm_cfg frm_cfg = { 0 };
332	reg_sser_rw_tr_cfg tr_cfg = { 0 };
333	reg_sser_rw_rec_cfg rec_cfg = { 0 };
334
335	DEBUG(pr_info("Init sync serial port %d\n", portnbr));
336
337	port->port_nbr = portnbr;
338	port->init_irqs = no_irq_setup;
339
340	port->out_rd_ptr = port->out_buffer;
341	port->out_buf_count = 0;
342
343	port->output = 1;
344	port->input = 0;
345
346	port->readp = port->flip;
347	port->writep = port->flip;
348	port->in_buffer_size = IN_BUFFER_SIZE;
349	port->in_buffer_len = 0;
350	port->inbufchunk = IN_DESCR_SIZE;
351
352	port->read_ts_idx = 0;
353	port->write_ts_idx = 0;
354
355	init_waitqueue_head(&port->out_wait_q);
356	init_waitqueue_head(&port->in_wait_q);
357
358	spin_lock_init(&port->lock);
359
360	cfg.out_clk_src = regk_sser_intern_clk;
361	cfg.out_clk_pol = regk_sser_pos;
362	cfg.clk_od_mode = regk_sser_no;
363	cfg.clk_dir = regk_sser_out;
364	cfg.gate_clk = regk_sser_no;
365	cfg.base_freq = regk_sser_f29_493;
366	cfg.clk_div = 256;
367	REG_WR(sser, port->regi_sser, rw_cfg, cfg);
368
369	frm_cfg.wordrate = DEFAULT_WORD_RATE;
370	frm_cfg.type = regk_sser_edge;
371	frm_cfg.frame_pin_dir = regk_sser_out;
372	frm_cfg.frame_pin_use = regk_sser_frm;
373	frm_cfg.status_pin_dir = regk_sser_in;
374	frm_cfg.status_pin_use = regk_sser_hold;
375	frm_cfg.out_on = regk_sser_tr;
376	frm_cfg.tr_delay = 1;
377	REG_WR(sser, port->regi_sser, rw_frm_cfg, frm_cfg);
378
379	tr_cfg.urun_stop = regk_sser_no;
380	tr_cfg.sample_size = 7;
381	tr_cfg.sh_dir = regk_sser_msbfirst;
382	tr_cfg.use_dma = port->use_dma ? regk_sser_yes : regk_sser_no;
383#if 0
384	tr_cfg.rate_ctrl = regk_sser_bulk;
385	tr_cfg.data_pin_use = regk_sser_dout;
386#else
387	tr_cfg.rate_ctrl = regk_sser_iso;
388	tr_cfg.data_pin_use = regk_sser_dout;
389#endif
390	tr_cfg.bulk_wspace = 1;
391	REG_WR(sser, port->regi_sser, rw_tr_cfg, tr_cfg);
392
393	rec_cfg.sample_size = 7;
394	rec_cfg.sh_dir = regk_sser_msbfirst;
395	rec_cfg.use_dma = port->use_dma ? regk_sser_yes : regk_sser_no;
396	rec_cfg.fifo_thr = regk_sser_inf;
397	REG_WR(sser, port->regi_sser, rw_rec_cfg, rec_cfg);
398
399#ifdef SYNC_SER_DMA
400	{
401		int i;
402		/* Setup the descriptor ring for dma out/transmit. */
403		for (i = 0; i < NBR_OUT_DESCR; i++) {
404			dma_descr_data *descr = &port->out_descr[i];
405			descr->wait = 0;
406			descr->intr = 1;
407			descr->eol = 0;
408			descr->out_eop = 0;
409			descr->next =
410				(dma_descr_data *)virt_to_phys(&descr[i+1]);
411		}
412	}
413
414	/* Create a ring from the list. */
415	port->out_descr[NBR_OUT_DESCR-1].next =
416		(dma_descr_data *)virt_to_phys(&port->out_descr[0]);
417
418	/* Setup context for traversing the ring. */
419	port->active_tr_descr = &port->out_descr[0];
420	port->prev_tr_descr = &port->out_descr[NBR_OUT_DESCR-1];
421	port->catch_tr_descr = &port->out_descr[0];
422#endif
423}
424
425static inline int sync_data_avail(struct sync_port *port)
426{
427	return port->in_buffer_len;
428}
429
430static int sync_serial_open(struct inode *inode, struct file *file)
431{
432	int ret = 0;
433	int dev = iminor(inode);
434	struct sync_port *port;
435#ifdef SYNC_SER_DMA
436	reg_dma_rw_cfg cfg = { .en = regk_dma_yes };
437	reg_dma_rw_intr_mask intr_mask = { .data = regk_dma_yes };
438#endif
439
440	DEBUG(pr_debug("Open sync serial port %d\n", dev));
441
442	if (dev < 0 || dev >= NBR_PORTS || !ports[dev].enabled) {
443		DEBUG(pr_info("Invalid minor %d\n", dev));
444		return -ENODEV;
445	}
446	port = &ports[dev];
447	/* Allow open this device twice (assuming one reader and one writer) */
448	if (port->busy == 2) {
449		DEBUG(pr_info("syncser%d is busy\n", dev));
450		return -EBUSY;
451	}
452
453	mutex_lock(&sync_serial_mutex);
454
455	/* Clear any stale date left in the flip buffer */
456	port->readp = port->writep = port->flip;
457	port->in_buffer_len = 0;
458	port->read_ts_idx = 0;
459	port->write_ts_idx = 0;
460
461	if (port->init_irqs != no_irq_setup) {
462		/* Init only on first call. */
463		port->busy++;
464		mutex_unlock(&sync_serial_mutex);
465		return 0;
466	}
467	if (port->use_dma) {
468#ifdef SYNC_SER_DMA
469		const char *tmp;
470		DEBUG(pr_info("Using DMA for syncser%d\n", dev));
471
472		tmp = dev == 0 ? "syncser0 tx" : "syncser1 tx";
473		if (request_irq(port->dma_out_intr_vect, tr_interrupt, 0,
474				tmp, port)) {
475			pr_err("Can't alloc syncser%d TX IRQ", dev);
476			ret = -EBUSY;
477			goto unlock_and_exit;
478		}
479		if (artpec_request_dma(port->dma_out_nbr, tmp,
480				DMA_VERBOSE_ON_ERROR, 0, port->req_dma)) {
481			free_irq(port->dma_out_intr_vect, port);
482			pr_err("Can't alloc syncser%d TX DMA", dev);
483			ret = -EBUSY;
484			goto unlock_and_exit;
485		}
486		tmp = dev == 0 ? "syncser0 rx" : "syncser1 rx";
487		if (request_irq(port->dma_in_intr_vect, rx_interrupt, 0,
488				tmp, port)) {
489			artpec_free_dma(port->dma_out_nbr);
490			free_irq(port->dma_out_intr_vect, port);
491			pr_err("Can't alloc syncser%d RX IRQ", dev);
492			ret = -EBUSY;
493			goto unlock_and_exit;
494		}
495		if (artpec_request_dma(port->dma_in_nbr, tmp,
496				DMA_VERBOSE_ON_ERROR, 0, port->req_dma)) {
497			artpec_free_dma(port->dma_out_nbr);
498			free_irq(port->dma_out_intr_vect, port);
499			free_irq(port->dma_in_intr_vect, port);
500			pr_err("Can't alloc syncser%d RX DMA", dev);
501			ret = -EBUSY;
502			goto unlock_and_exit;
503		}
504		/* Enable DMAs */
505		REG_WR(dma, port->regi_dmain, rw_cfg, cfg);
506		REG_WR(dma, port->regi_dmaout, rw_cfg, cfg);
507		/* Enable DMA IRQs */
508		REG_WR(dma, port->regi_dmain, rw_intr_mask, intr_mask);
509		REG_WR(dma, port->regi_dmaout, rw_intr_mask, intr_mask);
510		/* Set up wordsize = 1 for DMAs. */
511		DMA_WR_CMD(port->regi_dmain, regk_dma_set_w_size1);
512		DMA_WR_CMD(port->regi_dmaout, regk_dma_set_w_size1);
513
514		start_dma_in(port);
515		port->init_irqs = dma_irq_setup;
516#endif
517	} else { /* !port->use_dma */
518#ifdef SYNC_SER_MANUAL
519		const char *tmp = dev == 0 ? "syncser0 manual irq" :
520					     "syncser1 manual irq";
521		if (request_irq(port->syncser_intr_vect, manual_interrupt,
522				0, tmp, port)) {
523			pr_err("Can't alloc syncser%d manual irq",
524				dev);
525			ret = -EBUSY;
526			goto unlock_and_exit;
527		}
528		port->init_irqs = manual_irq_setup;
529#else
530		panic("sync_serial: Manual mode not supported\n");
531#endif /* SYNC_SER_MANUAL */
532	}
533	port->busy++;
534	ret = 0;
535
536unlock_and_exit:
537	mutex_unlock(&sync_serial_mutex);
538	return ret;
539}
540
541static int sync_serial_release(struct inode *inode, struct file *file)
542{
543	int dev = iminor(inode);
544	struct sync_port *port;
545
546	if (dev < 0 || dev >= NBR_PORTS || !ports[dev].enabled) {
547		DEBUG(pr_info("Invalid minor %d\n", dev));
548		return -ENODEV;
549	}
550	port = &ports[dev];
551	if (port->busy)
552		port->busy--;
553	if (!port->busy)
554		/* XXX */;
555	return 0;
556}
557
558static unsigned int sync_serial_poll(struct file *file, poll_table *wait)
559{
560	int dev = iminor(file_inode(file));
561	unsigned int mask = 0;
562	struct sync_port *port;
563	DEBUGPOLL(
564	static unsigned int prev_mask;
565	);
566
567	port = &ports[dev];
568
569	if (!port->started)
570		sync_serial_start_port(port);
571
572	poll_wait(file, &port->out_wait_q, wait);
573	poll_wait(file, &port->in_wait_q, wait);
574
575	/* No active transfer, descriptors are available */
576	if (port->output && !port->tr_running)
577		mask |= POLLOUT | POLLWRNORM;
578
579	/* Descriptor and buffer space available. */
580	if (port->output &&
581	    port->active_tr_descr != port->catch_tr_descr &&
582	    port->out_buf_count < OUT_BUFFER_SIZE)
583		mask |=  POLLOUT | POLLWRNORM;
584
585	/* At least an inbufchunk of data */
586	if (port->input && sync_data_avail(port) >= port->inbufchunk)
587		mask |= POLLIN | POLLRDNORM;
588
589	DEBUGPOLL(
590	if (mask != prev_mask)
591		pr_info("sync_serial_poll: mask 0x%08X %s %s\n",
592			mask,
593			mask & POLLOUT ? "POLLOUT" : "",
594			mask & POLLIN ? "POLLIN" : "");
595		prev_mask = mask;
596	);
597	return mask;
598}
599
600static ssize_t __sync_serial_read(struct file *file,
601				  char __user *buf,
602				  size_t count,
603				  loff_t *ppos,
604				  struct timespec *ts)
605{
606	unsigned long flags;
607	int dev = MINOR(file_inode(file)->i_rdev);
608	int avail;
609	struct sync_port *port;
610	unsigned char *start;
611	unsigned char *end;
612
613	if (dev < 0 || dev >= NBR_PORTS || !ports[dev].enabled) {
614		DEBUG(pr_info("Invalid minor %d\n", dev));
615		return -ENODEV;
616	}
617	port = &ports[dev];
618
619	if (!port->started)
620		sync_serial_start_port(port);
621
622	/* Calculate number of available bytes */
623	/* Save pointers to avoid that they are modified by interrupt */
624	spin_lock_irqsave(&port->lock, flags);
625	start = port->readp;
626	end = port->writep;
627	spin_unlock_irqrestore(&port->lock, flags);
628
629	while ((start == end) && !port->in_buffer_len) {
630		if (file->f_flags & O_NONBLOCK)
631			return -EAGAIN;
632
633		wait_event_interruptible(port->in_wait_q,
634					 !(start == end && !port->full));
635
636		if (signal_pending(current))
637			return -EINTR;
638
639		spin_lock_irqsave(&port->lock, flags);
640		start = port->readp;
641		end = port->writep;
642		spin_unlock_irqrestore(&port->lock, flags);
643	}
644
645	DEBUGREAD(pr_info("R%d c %d ri %u wi %u /%u\n",
646			  dev, count,
647			  start - port->flip, end - port->flip,
648			  port->in_buffer_size));
649
650	/* Lazy read, never return wrapped data. */
651	if (end > start)
652		avail = end - start;
653	else
654		avail = port->flip + port->in_buffer_size - start;
655
656	count = count > avail ? avail : count;
657	if (copy_to_user(buf, start, count))
658		return -EFAULT;
659
660	/* If timestamp requested, find timestamp of first returned byte
661	 * and copy it.
662	 * N.B: Applications that request timstamps MUST read data in
663	 * chunks that are multiples of IN_DESCR_SIZE.
664	 * Otherwise the timestamps will not be aligned to the data read.
665	 */
666	if (ts != NULL) {
667		int idx = port->read_ts_idx;
668		memcpy(ts, &port->timestamp[idx], sizeof(struct timespec));
669		port->read_ts_idx += count / IN_DESCR_SIZE;
670		if (port->read_ts_idx >= NBR_IN_DESCR)
671			port->read_ts_idx = 0;
672	}
673
674	spin_lock_irqsave(&port->lock, flags);
675	port->readp += count;
676	/* Check for wrap */
677	if (port->readp >= port->flip + port->in_buffer_size)
678		port->readp = port->flip;
679	port->in_buffer_len -= count;
680	port->full = 0;
681	spin_unlock_irqrestore(&port->lock, flags);
682
683	DEBUGREAD(pr_info("r %d\n", count));
684
685	return count;
686}
687
688static ssize_t sync_serial_input(struct file *file, unsigned long arg)
689{
690	struct ssp_request req;
691	int count;
692	int ret;
693
694	/* Copy the request structure from user-mode. */
695	ret = copy_from_user(&req, (struct ssp_request __user *)arg,
696		sizeof(struct ssp_request));
697
698	if (ret) {
699		DEBUG(pr_info("sync_serial_input copy from user failed\n"));
700		return -EFAULT;
701	}
702
703	/* To get the timestamps aligned, make sure that 'len'
704	 * is a multiple of IN_DESCR_SIZE.
705	 */
706	if ((req.len % IN_DESCR_SIZE) != 0) {
707		DEBUG(pr_info("sync_serial: req.len %x, IN_DESCR_SIZE %x\n",
708			      req.len, IN_DESCR_SIZE));
709		return -EFAULT;
710	}
711
712	/* Do the actual read. */
713	/* Note that req.buf is actually a pointer to user space. */
714	count = __sync_serial_read(file, req.buf, req.len,
715				   NULL, &req.ts);
716
717	if (count < 0) {
718		DEBUG(pr_info("sync_serial_input read failed\n"));
719		return count;
720	}
721
722	/* Copy the request back to user-mode. */
723	ret = copy_to_user((struct ssp_request __user *)arg, &req,
724		sizeof(struct ssp_request));
725
726	if (ret) {
727		DEBUG(pr_info("syncser input copy2user failed\n"));
728		return -EFAULT;
729	}
730
731	/* Return the number of bytes read. */
732	return count;
733}
734
735
736static int sync_serial_ioctl_unlocked(struct file *file,
737				      unsigned int cmd, unsigned long arg)
738{
739	int return_val = 0;
740	int dma_w_size = regk_dma_set_w_size1;
741	int dev = iminor(file_inode(file));
742	struct sync_port *port;
743	reg_sser_rw_tr_cfg tr_cfg;
744	reg_sser_rw_rec_cfg rec_cfg;
745	reg_sser_rw_frm_cfg frm_cfg;
746	reg_sser_rw_cfg gen_cfg;
747	reg_sser_rw_intr_mask intr_mask;
748
749	if (dev < 0 || dev >= NBR_PORTS || !ports[dev].enabled) {
750		DEBUG(pr_info("Invalid minor %d\n", dev));
751		return -1;
752	}
753
754	if (cmd == SSP_INPUT)
755		return sync_serial_input(file, arg);
756
757	port = &ports[dev];
758	spin_lock_irq(&port->lock);
759
760	tr_cfg = REG_RD(sser, port->regi_sser, rw_tr_cfg);
761	rec_cfg = REG_RD(sser, port->regi_sser, rw_rec_cfg);
762	frm_cfg = REG_RD(sser, port->regi_sser, rw_frm_cfg);
763	gen_cfg = REG_RD(sser, port->regi_sser, rw_cfg);
764	intr_mask = REG_RD(sser, port->regi_sser, rw_intr_mask);
765
766	switch (cmd) {
767	case SSP_SPEED:
768		if (GET_SPEED(arg) == CODEC) {
769			unsigned int freq;
770
771			gen_cfg.base_freq = regk_sser_f32;
772
773			/* Clock divider will internally be
774			 * gen_cfg.clk_div + 1.
775			 */
776
777			freq = GET_FREQ(arg);
778			switch (freq) {
779			case FREQ_32kHz:
780			case FREQ_64kHz:
781			case FREQ_128kHz:
782			case FREQ_256kHz:
783				gen_cfg.clk_div = 125 *
784					(1 << (freq - FREQ_256kHz)) - 1;
785				break;
786			case FREQ_512kHz:
787				gen_cfg.clk_div = 62;
788				break;
789			case FREQ_1MHz:
790			case FREQ_2MHz:
791			case FREQ_4MHz:
792				gen_cfg.clk_div = 8 * (1 << freq) - 1;
793				break;
794			}
795		} else if (GET_SPEED(arg) == CODEC_f32768) {
796			gen_cfg.base_freq = regk_sser_f32_768;
797			switch (GET_FREQ(arg)) {
798			case FREQ_4096kHz:
799				gen_cfg.clk_div = 7;
800				break;
801			default:
802				spin_unlock_irq(&port->lock);
803				return -EINVAL;
804			}
805		} else {
806			gen_cfg.base_freq = regk_sser_f29_493;
807			switch (GET_SPEED(arg)) {
808			case SSP150:
809				gen_cfg.clk_div = 29493000 / (150 * 8) - 1;
810				break;
811			case SSP300:
812				gen_cfg.clk_div = 29493000 / (300 * 8) - 1;
813				break;
814			case SSP600:
815				gen_cfg.clk_div = 29493000 / (600 * 8) - 1;
816				break;
817			case SSP1200:
818				gen_cfg.clk_div = 29493000 / (1200 * 8) - 1;
819				break;
820			case SSP2400:
821				gen_cfg.clk_div = 29493000 / (2400 * 8) - 1;
822				break;
823			case SSP4800:
824				gen_cfg.clk_div = 29493000 / (4800 * 8) - 1;
825				break;
826			case SSP9600:
827				gen_cfg.clk_div = 29493000 / (9600 * 8) - 1;
828				break;
829			case SSP19200:
830				gen_cfg.clk_div = 29493000 / (19200 * 8) - 1;
831				break;
832			case SSP28800:
833				gen_cfg.clk_div = 29493000 / (28800 * 8) - 1;
834				break;
835			case SSP57600:
836				gen_cfg.clk_div = 29493000 / (57600 * 8) - 1;
837				break;
838			case SSP115200:
839				gen_cfg.clk_div = 29493000 / (115200 * 8) - 1;
840				break;
841			case SSP230400:
842				gen_cfg.clk_div = 29493000 / (230400 * 8) - 1;
843				break;
844			case SSP460800:
845				gen_cfg.clk_div = 29493000 / (460800 * 8) - 1;
846				break;
847			case SSP921600:
848				gen_cfg.clk_div = 29493000 / (921600 * 8) - 1;
849				break;
850			case SSP3125000:
851				gen_cfg.base_freq = regk_sser_f100;
852				gen_cfg.clk_div = 100000000 / (3125000 * 8) - 1;
853				break;
854
855			}
856		}
857		frm_cfg.wordrate = GET_WORD_RATE(arg);
858
859		break;
860	case SSP_MODE:
861		switch (arg) {
862		case MASTER_OUTPUT:
863			port->output = 1;
864			port->input = 0;
865			frm_cfg.out_on = regk_sser_tr;
866			frm_cfg.frame_pin_dir = regk_sser_out;
867			gen_cfg.clk_dir = regk_sser_out;
868			break;
869		case SLAVE_OUTPUT:
870			port->output = 1;
871			port->input = 0;
872			frm_cfg.frame_pin_dir = regk_sser_in;
873			gen_cfg.clk_dir = regk_sser_in;
874			break;
875		case MASTER_INPUT:
876			port->output = 0;
877			port->input = 1;
878			frm_cfg.frame_pin_dir = regk_sser_out;
879			frm_cfg.out_on = regk_sser_intern_tb;
880			gen_cfg.clk_dir = regk_sser_out;
881			break;
882		case SLAVE_INPUT:
883			port->output = 0;
884			port->input = 1;
885			frm_cfg.frame_pin_dir = regk_sser_in;
886			gen_cfg.clk_dir = regk_sser_in;
887			break;
888		case MASTER_BIDIR:
889			port->output = 1;
890			port->input = 1;
891			frm_cfg.frame_pin_dir = regk_sser_out;
892			frm_cfg.out_on = regk_sser_intern_tb;
893			gen_cfg.clk_dir = regk_sser_out;
894			break;
895		case SLAVE_BIDIR:
896			port->output = 1;
897			port->input = 1;
898			frm_cfg.frame_pin_dir = regk_sser_in;
899			gen_cfg.clk_dir = regk_sser_in;
900			break;
901		default:
902			spin_unlock_irq(&port->lock);
903			return -EINVAL;
904		}
905		if (!port->use_dma || arg == MASTER_OUTPUT ||
906				arg == SLAVE_OUTPUT)
907			intr_mask.rdav = regk_sser_yes;
908		break;
909	case SSP_FRAME_SYNC:
910		if (arg & NORMAL_SYNC) {
911			frm_cfg.rec_delay = 1;
912			frm_cfg.tr_delay = 1;
913		} else if (arg & EARLY_SYNC)
914			frm_cfg.rec_delay = frm_cfg.tr_delay = 0;
915		else if (arg & LATE_SYNC) {
916			frm_cfg.tr_delay = 2;
917			frm_cfg.rec_delay = 2;
918		} else if (arg & SECOND_WORD_SYNC) {
919			frm_cfg.rec_delay = 7;
920			frm_cfg.tr_delay = 1;
921		}
922
923		tr_cfg.bulk_wspace = frm_cfg.tr_delay;
924		frm_cfg.early_wend = regk_sser_yes;
925		if (arg & BIT_SYNC)
926			frm_cfg.type = regk_sser_edge;
927		else if (arg & WORD_SYNC)
928			frm_cfg.type = regk_sser_level;
929		else if (arg & EXTENDED_SYNC)
930			frm_cfg.early_wend = regk_sser_no;
931
932		if (arg & SYNC_ON)
933			frm_cfg.frame_pin_use = regk_sser_frm;
934		else if (arg & SYNC_OFF)
935			frm_cfg.frame_pin_use = regk_sser_gio0;
936
937		dma_w_size = regk_dma_set_w_size2;
938		if (arg & WORD_SIZE_8) {
939			rec_cfg.sample_size = tr_cfg.sample_size = 7;
940			dma_w_size = regk_dma_set_w_size1;
941		} else if (arg & WORD_SIZE_12)
942			rec_cfg.sample_size = tr_cfg.sample_size = 11;
943		else if (arg & WORD_SIZE_16)
944			rec_cfg.sample_size = tr_cfg.sample_size = 15;
945		else if (arg & WORD_SIZE_24)
946			rec_cfg.sample_size = tr_cfg.sample_size = 23;
947		else if (arg & WORD_SIZE_32)
948			rec_cfg.sample_size = tr_cfg.sample_size = 31;
949
950		if (arg & BIT_ORDER_MSB)
951			rec_cfg.sh_dir = tr_cfg.sh_dir = regk_sser_msbfirst;
952		else if (arg & BIT_ORDER_LSB)
953			rec_cfg.sh_dir = tr_cfg.sh_dir = regk_sser_lsbfirst;
954
955		if (arg & FLOW_CONTROL_ENABLE) {
956			frm_cfg.status_pin_use = regk_sser_frm;
957			rec_cfg.fifo_thr = regk_sser_thr16;
958		} else if (arg & FLOW_CONTROL_DISABLE) {
959			frm_cfg.status_pin_use = regk_sser_gio0;
960			rec_cfg.fifo_thr = regk_sser_inf;
961		}
962
963		if (arg & CLOCK_NOT_GATED)
964			gen_cfg.gate_clk = regk_sser_no;
965		else if (arg & CLOCK_GATED)
966			gen_cfg.gate_clk = regk_sser_yes;
967
968		break;
969	case SSP_IPOLARITY:
970		/* NOTE!! negedge is considered NORMAL */
971		if (arg & CLOCK_NORMAL)
972			rec_cfg.clk_pol = regk_sser_neg;
973		else if (arg & CLOCK_INVERT)
974			rec_cfg.clk_pol = regk_sser_pos;
975
976		if (arg & FRAME_NORMAL)
977			frm_cfg.level = regk_sser_pos_hi;
978		else if (arg & FRAME_INVERT)
979			frm_cfg.level = regk_sser_neg_lo;
980
981		if (arg & STATUS_NORMAL)
982			gen_cfg.hold_pol = regk_sser_pos;
983		else if (arg & STATUS_INVERT)
984			gen_cfg.hold_pol = regk_sser_neg;
985		break;
986	case SSP_OPOLARITY:
987		if (arg & CLOCK_NORMAL)
988			gen_cfg.out_clk_pol = regk_sser_pos;
989		else if (arg & CLOCK_INVERT)
990			gen_cfg.out_clk_pol = regk_sser_neg;
991
992		if (arg & FRAME_NORMAL)
993			frm_cfg.level = regk_sser_pos_hi;
994		else if (arg & FRAME_INVERT)
995			frm_cfg.level = regk_sser_neg_lo;
996
997		if (arg & STATUS_NORMAL)
998			gen_cfg.hold_pol = regk_sser_pos;
999		else if (arg & STATUS_INVERT)
1000			gen_cfg.hold_pol = regk_sser_neg;
1001		break;
1002	case SSP_SPI:
1003		rec_cfg.fifo_thr = regk_sser_inf;
1004		rec_cfg.sh_dir = tr_cfg.sh_dir = regk_sser_msbfirst;
1005		rec_cfg.sample_size = tr_cfg.sample_size = 7;
1006		frm_cfg.frame_pin_use = regk_sser_frm;
1007		frm_cfg.type = regk_sser_level;
1008		frm_cfg.tr_delay = 1;
1009		frm_cfg.level = regk_sser_neg_lo;
1010		if (arg & SPI_SLAVE) {
1011			rec_cfg.clk_pol = regk_sser_neg;
1012			gen_cfg.clk_dir = regk_sser_in;
1013			port->input = 1;
1014			port->output = 0;
1015		} else {
1016			gen_cfg.out_clk_pol = regk_sser_pos;
1017			port->input = 0;
1018			port->output = 1;
1019			gen_cfg.clk_dir = regk_sser_out;
1020		}
1021		break;
1022	case SSP_INBUFCHUNK:
1023		break;
1024	default:
1025		return_val = -1;
1026	}
1027
1028
1029	if (port->started) {
1030		rec_cfg.rec_en = port->input;
1031		gen_cfg.en = (port->output | port->input);
1032	}
1033
1034	REG_WR(sser, port->regi_sser, rw_tr_cfg, tr_cfg);
1035	REG_WR(sser, port->regi_sser, rw_rec_cfg, rec_cfg);
1036	REG_WR(sser, port->regi_sser, rw_frm_cfg, frm_cfg);
1037	REG_WR(sser, port->regi_sser, rw_intr_mask, intr_mask);
1038	REG_WR(sser, port->regi_sser, rw_cfg, gen_cfg);
1039
1040
1041	if (cmd == SSP_FRAME_SYNC && (arg & (WORD_SIZE_8 | WORD_SIZE_12 |
1042			WORD_SIZE_16 | WORD_SIZE_24 | WORD_SIZE_32))) {
1043		int en = gen_cfg.en;
1044		gen_cfg.en = 0;
1045		REG_WR(sser, port->regi_sser, rw_cfg, gen_cfg);
1046		/* ##### Should DMA be stoped before we change dma size? */
1047		DMA_WR_CMD(port->regi_dmain, dma_w_size);
1048		DMA_WR_CMD(port->regi_dmaout, dma_w_size);
1049		gen_cfg.en = en;
1050		REG_WR(sser, port->regi_sser, rw_cfg, gen_cfg);
1051	}
1052
1053	spin_unlock_irq(&port->lock);
1054	return return_val;
1055}
1056
1057static long sync_serial_ioctl(struct file *file,
1058		unsigned int cmd, unsigned long arg)
1059{
1060	long ret;
1061
1062	mutex_lock(&sync_serial_mutex);
1063	ret = sync_serial_ioctl_unlocked(file, cmd, arg);
1064	mutex_unlock(&sync_serial_mutex);
1065
1066	return ret;
1067}
1068
1069/* NOTE: sync_serial_write does not support concurrency */
1070static ssize_t sync_serial_write(struct file *file, const char __user *buf,
1071				 size_t count, loff_t *ppos)
1072{
1073	int dev = iminor(file_inode(file));
1074	DECLARE_WAITQUEUE(wait, current);
1075	struct sync_port *port;
1076	int trunc_count;
1077	unsigned long flags;
1078	int bytes_free;
1079	int out_buf_count;
1080
1081	unsigned char *rd_ptr;       /* First allocated byte in the buffer */
1082	unsigned char *wr_ptr;       /* First free byte in the buffer */
1083	unsigned char *buf_stop_ptr; /* Last byte + 1 */
1084
1085	if (dev < 0 || dev >= NBR_PORTS || !ports[dev].enabled) {
1086		DEBUG(pr_info("Invalid minor %d\n", dev));
1087		return -ENODEV;
1088	}
1089	port = &ports[dev];
1090
1091	/* |<-         OUT_BUFFER_SIZE                          ->|
1092	 *           |<- out_buf_count ->|
1093	 *                               |<- trunc_count ->| ...->|
1094	 *  ______________________________________________________
1095	 * |  free   |   data            | free                   |
1096	 * |_________|___________________|________________________|
1097	 *           ^ rd_ptr            ^ wr_ptr
1098	 */
1099	DEBUGWRITE(pr_info("W d%d c %u a: %p c: %p\n",
1100			   port->port_nbr, count, port->active_tr_descr,
1101			   port->catch_tr_descr));
1102
1103	/* Read variables that may be updated by interrupts */
1104	spin_lock_irqsave(&port->lock, flags);
1105	rd_ptr = port->out_rd_ptr;
1106	out_buf_count = port->out_buf_count;
1107	spin_unlock_irqrestore(&port->lock, flags);
1108
1109	/* Check if resources are available */
1110	if (port->tr_running &&
1111	    ((port->use_dma && port->active_tr_descr == port->catch_tr_descr) ||
1112	     out_buf_count >= OUT_BUFFER_SIZE)) {
1113		DEBUGWRITE(pr_info("sser%d full\n", dev));
1114		return -EAGAIN;
1115	}
1116
1117	buf_stop_ptr = port->out_buffer + OUT_BUFFER_SIZE;
1118
1119	/* Determine pointer to the first free byte, before copying. */
1120	wr_ptr = rd_ptr + out_buf_count;
1121	if (wr_ptr >= buf_stop_ptr)
1122		wr_ptr -= OUT_BUFFER_SIZE;
1123
1124	/* If we wrap the ring buffer, let the user space program handle it by
1125	 * truncating the data. This could be more elegant, small buffer
1126	 * fragments may occur.
1127	 */
1128	bytes_free = OUT_BUFFER_SIZE - out_buf_count;
1129	if (wr_ptr + bytes_free > buf_stop_ptr)
1130		bytes_free = buf_stop_ptr - wr_ptr;
1131	trunc_count = (count < bytes_free) ? count : bytes_free;
1132
1133	if (copy_from_user(wr_ptr, buf, trunc_count))
1134		return -EFAULT;
1135
1136	DEBUGOUTBUF(pr_info("%-4d + %-4d = %-4d     %p %p %p\n",
1137			    out_buf_count, trunc_count,
1138			    port->out_buf_count, port->out_buffer,
1139			    wr_ptr, buf_stop_ptr));
1140
1141	/* Make sure transmitter/receiver is running */
1142	if (!port->started) {
1143		reg_sser_rw_cfg cfg = REG_RD(sser, port->regi_sser, rw_cfg);
1144		reg_sser_rw_rec_cfg rec_cfg =
1145			REG_RD(sser, port->regi_sser, rw_rec_cfg);
1146		cfg.en = regk_sser_yes;
1147		rec_cfg.rec_en = port->input;
1148		REG_WR(sser, port->regi_sser, rw_cfg, cfg);
1149		REG_WR(sser, port->regi_sser, rw_rec_cfg, rec_cfg);
1150		port->started = 1;
1151	}
1152
1153	/* Setup wait if blocking */
1154	if (!(file->f_flags & O_NONBLOCK)) {
1155		add_wait_queue(&port->out_wait_q, &wait);
1156		set_current_state(TASK_INTERRUPTIBLE);
1157	}
1158
1159	spin_lock_irqsave(&port->lock, flags);
1160	port->out_buf_count += trunc_count;
1161	if (port->use_dma) {
1162#ifdef SYNC_SER_DMA
1163		start_dma_out(port, wr_ptr, trunc_count);
1164#endif
1165	} else if (!port->tr_running) {
1166#ifdef SYNC_SER_MANUAL
1167		reg_sser_rw_intr_mask intr_mask;
1168		intr_mask = REG_RD(sser, port->regi_sser, rw_intr_mask);
1169		/* Start sender by writing data */
1170		send_word(port);
1171		/* and enable transmitter ready IRQ */
1172		intr_mask.trdy = 1;
1173		REG_WR(sser, port->regi_sser, rw_intr_mask, intr_mask);
1174#endif
1175	}
1176	spin_unlock_irqrestore(&port->lock, flags);
1177
1178	/* Exit if non blocking */
1179	if (file->f_flags & O_NONBLOCK) {
1180		DEBUGWRITE(pr_info("w d%d c %u  %08x\n",
1181				   port->port_nbr, trunc_count,
1182				   REG_RD_INT(dma, port->regi_dmaout, r_intr)));
1183		return trunc_count;
1184	}
1185
1186	schedule();
1187	remove_wait_queue(&port->out_wait_q, &wait);
1188
1189	if (signal_pending(current))
1190		return -EINTR;
1191
1192	DEBUGWRITE(pr_info("w d%d c %u\n", port->port_nbr, trunc_count));
1193	return trunc_count;
1194}
1195
1196static ssize_t sync_serial_read(struct file *file, char __user *buf,
1197				size_t count, loff_t *ppos)
1198{
1199	return __sync_serial_read(file, buf, count, ppos, NULL);
1200}
1201
1202#ifdef SYNC_SER_MANUAL
1203static void send_word(struct sync_port *port)
1204{
1205	reg_sser_rw_tr_cfg tr_cfg = REG_RD(sser, port->regi_sser, rw_tr_cfg);
1206	reg_sser_rw_tr_data tr_data =  {0};
1207
1208	switch (tr_cfg.sample_size) {
1209	case 8:
1210		port->out_buf_count--;
1211		tr_data.data = *port->out_rd_ptr++;
1212		REG_WR(sser, port->regi_sser, rw_tr_data, tr_data);
1213		if (port->out_rd_ptr >= port->out_buffer + OUT_BUFFER_SIZE)
1214			port->out_rd_ptr = port->out_buffer;
1215		break;
1216	case 12:
1217	{
1218		int data = (*port->out_rd_ptr++) << 8;
1219		data |= *port->out_rd_ptr++;
1220		port->out_buf_count -= 2;
1221		tr_data.data = data;
1222		REG_WR(sser, port->regi_sser, rw_tr_data, tr_data);
1223		if (port->out_rd_ptr >= port->out_buffer + OUT_BUFFER_SIZE)
1224			port->out_rd_ptr = port->out_buffer;
1225		break;
1226	}
1227	case 16:
1228		port->out_buf_count -= 2;
1229		tr_data.data = *(unsigned short *)port->out_rd_ptr;
1230		REG_WR(sser, port->regi_sser, rw_tr_data, tr_data);
1231		port->out_rd_ptr += 2;
1232		if (port->out_rd_ptr >= port->out_buffer + OUT_BUFFER_SIZE)
1233			port->out_rd_ptr = port->out_buffer;
1234		break;
1235	case 24:
1236		port->out_buf_count -= 3;
1237		tr_data.data = *(unsigned short *)port->out_rd_ptr;
1238		REG_WR(sser, port->regi_sser, rw_tr_data, tr_data);
1239		port->out_rd_ptr += 2;
1240		tr_data.data = *port->out_rd_ptr++;
1241		REG_WR(sser, port->regi_sser, rw_tr_data, tr_data);
1242		if (port->out_rd_ptr >= port->out_buffer + OUT_BUFFER_SIZE)
1243			port->out_rd_ptr = port->out_buffer;
1244		break;
1245	case 32:
1246		port->out_buf_count -= 4;
1247		tr_data.data = *(unsigned short *)port->out_rd_ptr;
1248		REG_WR(sser, port->regi_sser, rw_tr_data, tr_data);
1249		port->out_rd_ptr += 2;
1250		tr_data.data = *(unsigned short *)port->out_rd_ptr;
1251		REG_WR(sser, port->regi_sser, rw_tr_data, tr_data);
1252		port->out_rd_ptr += 2;
1253		if (port->out_rd_ptr >= port->out_buffer + OUT_BUFFER_SIZE)
1254			port->out_rd_ptr = port->out_buffer;
1255		break;
1256	}
1257}
1258#endif
1259
1260#ifdef SYNC_SER_DMA
1261static void start_dma_out(struct sync_port *port, const char *data, int count)
1262{
1263	port->active_tr_descr->buf = (char *)virt_to_phys((char *)data);
1264	port->active_tr_descr->after = port->active_tr_descr->buf + count;
1265	port->active_tr_descr->intr = 1;
1266
1267	port->active_tr_descr->eol = 1;
1268	port->prev_tr_descr->eol = 0;
1269
1270	DEBUGTRDMA(pr_info("Inserting eolr:%p eol@:%p\n",
1271		port->prev_tr_descr, port->active_tr_descr));
1272	port->prev_tr_descr = port->active_tr_descr;
1273	port->active_tr_descr = phys_to_virt((int)port->active_tr_descr->next);
1274
1275	if (!port->tr_running) {
1276		reg_sser_rw_tr_cfg tr_cfg = REG_RD(sser, port->regi_sser,
1277			rw_tr_cfg);
1278
1279		port->out_context.next = NULL;
1280		port->out_context.saved_data =
1281			(dma_descr_data *)virt_to_phys(port->prev_tr_descr);
1282		port->out_context.saved_data_buf = port->prev_tr_descr->buf;
1283
1284		DMA_START_CONTEXT(port->regi_dmaout,
1285			virt_to_phys((char *)&port->out_context));
1286
1287		tr_cfg.tr_en = regk_sser_yes;
1288		REG_WR(sser, port->regi_sser, rw_tr_cfg, tr_cfg);
1289		DEBUGTRDMA(pr_info("dma s\n"););
1290	} else {
1291		DMA_CONTINUE_DATA(port->regi_dmaout);
1292		DEBUGTRDMA(pr_info("dma c\n"););
1293	}
1294
1295	port->tr_running = 1;
1296}
1297
1298static void start_dma_in(struct sync_port *port)
1299{
1300	int i;
1301	char *buf;
1302	unsigned long flags;
1303	spin_lock_irqsave(&port->lock, flags);
1304	port->writep = port->flip;
1305	spin_unlock_irqrestore(&port->lock, flags);
1306
1307	buf = (char *)virt_to_phys(port->in_buffer);
1308	for (i = 0; i < NBR_IN_DESCR; i++) {
1309		port->in_descr[i].buf = buf;
1310		port->in_descr[i].after = buf + port->inbufchunk;
1311		port->in_descr[i].intr = 1;
1312		port->in_descr[i].next =
1313			(dma_descr_data *)virt_to_phys(&port->in_descr[i+1]);
1314		port->in_descr[i].buf = buf;
1315		buf += port->inbufchunk;
1316	}
1317	/* Link the last descriptor to the first */
1318	port->in_descr[i-1].next =
1319		(dma_descr_data *)virt_to_phys(&port->in_descr[0]);
1320	port->in_descr[i-1].eol = regk_sser_yes;
1321	port->next_rx_desc = &port->in_descr[0];
1322	port->prev_rx_desc = &port->in_descr[NBR_IN_DESCR - 1];
1323	port->in_context.saved_data =
1324		(dma_descr_data *)virt_to_phys(&port->in_descr[0]);
1325	port->in_context.saved_data_buf = port->in_descr[0].buf;
1326	DMA_START_CONTEXT(port->regi_dmain, virt_to_phys(&port->in_context));
1327}
1328
1329static irqreturn_t tr_interrupt(int irq, void *dev_id)
1330{
1331	reg_dma_r_masked_intr masked;
1332	reg_dma_rw_ack_intr ack_intr = { .data = regk_dma_yes };
1333	reg_dma_rw_stat stat;
1334	int i;
1335	int found = 0;
1336	int stop_sser = 0;
1337
1338	for (i = 0; i < NBR_PORTS; i++) {
1339		struct sync_port *port = &ports[i];
1340		if (!port->enabled || !port->use_dma)
1341			continue;
1342
1343		/* IRQ active for the port? */
1344		masked = REG_RD(dma, port->regi_dmaout, r_masked_intr);
1345		if (!masked.data)
1346			continue;
1347
1348		found = 1;
1349
1350		/* Check if we should stop the DMA transfer */
1351		stat = REG_RD(dma, port->regi_dmaout, rw_stat);
1352		if (stat.list_state == regk_dma_data_at_eol)
1353			stop_sser = 1;
1354
1355		/* Clear IRQ */
1356		REG_WR(dma, port->regi_dmaout, rw_ack_intr, ack_intr);
1357
1358		if (!stop_sser) {
1359			/* The DMA has completed a descriptor, EOL was not
1360			 * encountered, so step relevant descriptor and
1361			 * datapointers forward. */
1362			int sent;
1363			sent = port->catch_tr_descr->after -
1364				port->catch_tr_descr->buf;
1365			DEBUGTXINT(pr_info("%-4d - %-4d = %-4d\t"
1366					   "in descr %p (ac: %p)\n",
1367					   port->out_buf_count, sent,
1368					   port->out_buf_count - sent,
1369					   port->catch_tr_descr,
1370					   port->active_tr_descr););
1371			port->out_buf_count -= sent;
1372			port->catch_tr_descr =
1373				phys_to_virt((int) port->catch_tr_descr->next);
1374			port->out_rd_ptr =
1375				phys_to_virt((int) port->catch_tr_descr->buf);
1376		} else {
1377			reg_sser_rw_tr_cfg tr_cfg;
1378			int j, sent;
1379			/* EOL handler.
1380			 * Note that if an EOL was encountered during the irq
1381			 * locked section of sync_ser_write the DMA will be
1382			 * restarted and the eol flag will be cleared.
1383			 * The remaining descriptors will be traversed by
1384			 * the descriptor interrupts as usual.
1385			 */
1386			j = 0;
1387			while (!port->catch_tr_descr->eol) {
1388				sent = port->catch_tr_descr->after -
1389					port->catch_tr_descr->buf;
1390				DEBUGOUTBUF(pr_info(
1391					"traversing descr %p -%d (%d)\n",
1392					port->catch_tr_descr,
1393					sent,
1394					port->out_buf_count));
1395				port->out_buf_count -= sent;
1396				port->catch_tr_descr = phys_to_virt(
1397					(int)port->catch_tr_descr->next);
1398				j++;
1399				if (j >= NBR_OUT_DESCR) {
1400					/* TODO: Reset and recover */
1401					panic("sync_serial: missing eol");
1402				}
1403			}
1404			sent = port->catch_tr_descr->after -
1405				port->catch_tr_descr->buf;
1406			DEBUGOUTBUF(pr_info("eol at descr %p -%d (%d)\n",
1407				port->catch_tr_descr,
1408				sent,
1409				port->out_buf_count));
1410
1411			port->out_buf_count -= sent;
1412
1413			/* Update read pointer to first free byte, we
1414			 * may already be writing data there. */
1415			port->out_rd_ptr =
1416				phys_to_virt((int) port->catch_tr_descr->after);
1417			if (port->out_rd_ptr > port->out_buffer +
1418					OUT_BUFFER_SIZE)
1419				port->out_rd_ptr = port->out_buffer;
1420
1421			tr_cfg = REG_RD(sser, port->regi_sser, rw_tr_cfg);
1422			DEBUGTXINT(pr_info(
1423				"tr_int DMA stop %d, set catch @ %p\n",
1424				port->out_buf_count,
1425				port->active_tr_descr));
1426			if (port->out_buf_count != 0)
1427				pr_err("sync_ser: buf not empty after eol\n");
1428			port->catch_tr_descr = port->active_tr_descr;
1429			port->tr_running = 0;
1430			tr_cfg.tr_en = regk_sser_no;
1431			REG_WR(sser, port->regi_sser, rw_tr_cfg, tr_cfg);
1432		}
1433		/* wake up the waiting process */
1434		wake_up_interruptible(&port->out_wait_q);
1435	}
1436	return IRQ_RETVAL(found);
1437} /* tr_interrupt */
1438
1439
1440static inline void handle_rx_packet(struct sync_port *port)
1441{
1442	int idx;
1443	reg_dma_rw_ack_intr ack_intr = { .data = regk_dma_yes };
1444	unsigned long flags;
1445
1446	DEBUGRXINT(pr_info("!"));
1447	spin_lock_irqsave(&port->lock, flags);
1448
1449	/* If we overrun the user experience is crap regardless if we
1450	 * drop new or old data. Its much easier to get it right when
1451	 * dropping new data so lets do that.
1452	 */
1453	if ((port->writep + port->inbufchunk <=
1454	     port->flip + port->in_buffer_size) &&
1455	    (port->in_buffer_len + port->inbufchunk < IN_BUFFER_SIZE)) {
1456		memcpy(port->writep,
1457		       phys_to_virt((unsigned)port->next_rx_desc->buf),
1458		       port->inbufchunk);
1459		port->writep += port->inbufchunk;
1460		if (port->writep >= port->flip + port->in_buffer_size)
1461			port->writep = port->flip;
1462
1463		/* Timestamp the new data chunk. */
1464		if (port->write_ts_idx == NBR_IN_DESCR)
1465			port->write_ts_idx = 0;
1466		idx = port->write_ts_idx++;
1467		do_posix_clock_monotonic_gettime(&port->timestamp[idx]);
1468		port->in_buffer_len += port->inbufchunk;
1469	}
1470	spin_unlock_irqrestore(&port->lock, flags);
1471
1472	port->next_rx_desc->eol = 1;
1473	port->prev_rx_desc->eol = 0;
1474	/* Cache bug workaround */
1475	flush_dma_descr(port->prev_rx_desc, 0);
1476	port->prev_rx_desc = port->next_rx_desc;
1477	port->next_rx_desc = phys_to_virt((unsigned)port->next_rx_desc->next);
1478	/* Cache bug workaround */
1479	flush_dma_descr(port->prev_rx_desc, 1);
1480	/* wake up the waiting process */
1481	wake_up_interruptible(&port->in_wait_q);
1482	DMA_CONTINUE(port->regi_dmain);
1483	REG_WR(dma, port->regi_dmain, rw_ack_intr, ack_intr);
1484
1485}
1486
1487static irqreturn_t rx_interrupt(int irq, void *dev_id)
1488{
1489	reg_dma_r_masked_intr masked;
1490
1491	int i;
1492	int found = 0;
1493
1494	DEBUG(pr_info("rx_interrupt\n"));
1495
1496	for (i = 0; i < NBR_PORTS; i++) {
1497		struct sync_port *port = &ports[i];
1498
1499		if (!port->enabled || !port->use_dma)
1500			continue;
1501
1502		masked = REG_RD(dma, port->regi_dmain, r_masked_intr);
1503
1504		if (!masked.data)
1505			continue;
1506
1507		/* Descriptor interrupt */
1508		found = 1;
1509		while (REG_RD(dma, port->regi_dmain, rw_data) !=
1510				virt_to_phys(port->next_rx_desc))
1511			handle_rx_packet(port);
1512	}
1513	return IRQ_RETVAL(found);
1514} /* rx_interrupt */
1515#endif /* SYNC_SER_DMA */
1516
1517#ifdef SYNC_SER_MANUAL
1518static irqreturn_t manual_interrupt(int irq, void *dev_id)
1519{
1520	unsigned long flags;
1521	int i;
1522	int found = 0;
1523	reg_sser_r_masked_intr masked;
1524
1525	for (i = 0; i < NBR_PORTS; i++) {
1526		struct sync_port *port = &ports[i];
1527
1528		if (!port->enabled || port->use_dma)
1529			continue;
1530
1531		masked = REG_RD(sser, port->regi_sser, r_masked_intr);
1532		/* Data received? */
1533		if (masked.rdav) {
1534			reg_sser_rw_rec_cfg rec_cfg =
1535				REG_RD(sser, port->regi_sser, rw_rec_cfg);
1536			reg_sser_r_rec_data data = REG_RD(sser,
1537				port->regi_sser, r_rec_data);
1538			found = 1;
1539			/* Read data */
1540			spin_lock_irqsave(&port->lock, flags);
1541			switch (rec_cfg.sample_size) {
1542			case 8:
1543				*port->writep++ = data.data & 0xff;
1544				break;
1545			case 12:
1546				*port->writep = (data.data & 0x0ff0) >> 4;
1547				*(port->writep + 1) = data.data & 0x0f;
1548				port->writep += 2;
1549				break;
1550			case 16:
1551				*(unsigned short *)port->writep = data.data;
1552				port->writep += 2;
1553				break;
1554			case 24:
1555				*(unsigned int *)port->writep = data.data;
1556				port->writep += 3;
1557				break;
1558			case 32:
1559				*(unsigned int *)port->writep = data.data;
1560				port->writep += 4;
1561				break;
1562			}
1563
1564			/* Wrap? */
1565			if (port->writep >= port->flip + port->in_buffer_size)
1566				port->writep = port->flip;
1567			if (port->writep == port->readp) {
1568				/* Receive buf overrun, discard oldest data */
1569				port->readp++;
1570				/* Wrap? */
1571				if (port->readp >= port->flip +
1572						port->in_buffer_size)
1573					port->readp = port->flip;
1574			}
1575			spin_unlock_irqrestore(&port->lock, flags);
1576			if (sync_data_avail(port) >= port->inbufchunk)
1577				/* Wake up application */
1578				wake_up_interruptible(&port->in_wait_q);
1579		}
1580
1581		/* Transmitter ready? */
1582		if (masked.trdy) {
1583			found = 1;
1584			/* More data to send */
1585			if (port->out_buf_count > 0)
1586				send_word(port);
1587			else {
1588				/* Transmission finished */
1589				reg_sser_rw_intr_mask intr_mask;
1590				intr_mask = REG_RD(sser, port->regi_sser,
1591					rw_intr_mask);
1592				intr_mask.trdy = 0;
1593				REG_WR(sser, port->regi_sser,
1594					rw_intr_mask, intr_mask);
1595				/* Wake up application */
1596				wake_up_interruptible(&port->out_wait_q);
1597			}
1598		}
1599	}
1600	return IRQ_RETVAL(found);
1601}
1602#endif
1603
1604static int __init etrax_sync_serial_init(void)
1605{
1606#if 1
1607	/* This code will be removed when we move to udev for all devices. */
1608	syncser_first = MKDEV(SYNC_SERIAL_MAJOR, 0);
1609	if (register_chrdev_region(syncser_first, minor_count, SYNCSER_NAME)) {
1610		pr_err("Failed to register major %d\n", SYNC_SERIAL_MAJOR);
1611		return -1;
1612	}
1613#else
1614	/* Allocate dynamic major number. */
1615	if (alloc_chrdev_region(&syncser_first, 0, minor_count, SYNCSER_NAME)) {
1616		pr_err("Failed to allocate character device region\n");
1617		return -1;
1618	}
1619#endif
1620	syncser_cdev = cdev_alloc();
1621	if (!syncser_cdev) {
1622		pr_err("Failed to allocate cdev for syncser\n");
1623		unregister_chrdev_region(syncser_first, minor_count);
1624		return -1;
1625	}
1626	cdev_init(syncser_cdev, &syncser_fops);
1627
1628	/* Create a sysfs class for syncser */
1629	syncser_class = class_create(THIS_MODULE, "syncser_class");
1630
1631	/* Initialize Ports */
1632#if defined(CONFIG_ETRAX_SYNCHRONOUS_SERIAL_PORT0)
1633	if (artpec_pinmux_alloc_fixed(PINMUX_SSER0)) {
1634		pr_warn("Unable to alloc pins for synchronous serial port 0\n");
1635		unregister_chrdev_region(syncser_first, minor_count);
1636		return -EIO;
1637	}
1638	initialize_port(0);
1639	ports[0].enabled = 1;
1640	/* Register with sysfs so udev can pick it up. */
1641	device_create(syncser_class, NULL, syncser_first, NULL,
1642		      "%s%d", SYNCSER_NAME, 0);
1643#endif
1644
1645#if defined(CONFIG_ETRAXFS) && defined(CONFIG_ETRAX_SYNCHRONOUS_SERIAL_PORT1)
1646	if (artpec_pinmux_alloc_fixed(PINMUX_SSER1)) {
1647		pr_warn("Unable to alloc pins for synchronous serial port 1\n");
1648		unregister_chrdev_region(syncser_first, minor_count);
1649		class_destroy(syncser_class);
1650		return -EIO;
1651	}
1652	initialize_port(1);
1653	ports[1].enabled = 1;
1654	/* Register with sysfs so udev can pick it up. */
1655	device_create(syncser_class, NULL, syncser_first, NULL,
1656		      "%s%d", SYNCSER_NAME, 0);
1657#endif
1658
1659	/* Add it to system */
1660	if (cdev_add(syncser_cdev, syncser_first, minor_count) < 0) {
1661		pr_err("Failed to add syncser as char device\n");
1662		device_destroy(syncser_class, syncser_first);
1663		class_destroy(syncser_class);
1664		cdev_del(syncser_cdev);
1665		unregister_chrdev_region(syncser_first, minor_count);
1666		return -1;
1667	}
1668
1669
1670	pr_info("ARTPEC synchronous serial port (%s: %d, %d)\n",
1671		SYNCSER_NAME, MAJOR(syncser_first), MINOR(syncser_first));
1672
1673	return 0;
1674}
1675
1676static void __exit etrax_sync_serial_exit(void)
1677{
1678	int i;
1679	device_destroy(syncser_class, syncser_first);
1680	class_destroy(syncser_class);
1681
1682	if (syncser_cdev) {
1683		cdev_del(syncser_cdev);
1684		unregister_chrdev_region(syncser_first, minor_count);
1685	}
1686	for (i = 0; i < NBR_PORTS; i++) {
1687		struct sync_port *port = &ports[i];
1688		if (port->init_irqs == dma_irq_setup) {
1689			/* Free dma irqs and dma channels. */
1690#ifdef SYNC_SER_DMA
1691			artpec_free_dma(port->dma_in_nbr);
1692			artpec_free_dma(port->dma_out_nbr);
1693			free_irq(port->dma_out_intr_vect, port);
1694			free_irq(port->dma_in_intr_vect, port);
1695#endif
1696		} else if (port->init_irqs == manual_irq_setup) {
1697			/* Free manual irq. */
1698			free_irq(port->syncser_intr_vect, port);
1699		}
1700	}
1701
1702	pr_info("ARTPEC synchronous serial port unregistered\n");
1703}
1704
1705module_init(etrax_sync_serial_init);
1706module_exit(etrax_sync_serial_exit);
1707
1708MODULE_LICENSE("GPL");
1709
1710