aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/staging/fwserial/fwserial.h
blob: 98b853d4acbcf16181984bf3f529c24f4bab3a1c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
#ifndef _FIREWIRE_FWSERIAL_H
#define _FIREWIRE_FWSERIAL_H

#include <linux/kernel.h>
#include <linux/tty.h>
#include <linux/tty_driver.h>
#include <linux/tty_flip.h>
#include <linux/list.h>
#include <linux/firewire.h>
#include <linux/firewire-constants.h>
#include <linux/spinlock.h>
#include <linux/rcupdate.h>
#include <linux/mutex.h>
#include <linux/serial.h>
#include <linux/serial_reg.h>
#include <linux/module.h>
#include <linux/seq_file.h>
#include <linux/debugfs.h>

#include "dma_fifo.h"

#ifdef FWTTY_PROFILING
#define DISTRIBUTION_MAX_SIZE     8192
#define DISTRIBUTION_MAX_INDEX    (ilog2(DISTRIBUTION_MAX_SIZE) + 1)
static inline void fwtty_profile_data(unsigned stat[], unsigned val)
{
	int n = (val) ? min(ilog2(val) + 1, DISTRIBUTION_MAX_INDEX) : 0;
	++stat[n];
}
#else
#define DISTRIBUTION_MAX_INDEX    0
#define fwtty_profile_data(st, n)
#endif

/* Parameters for both VIRT_CABLE_PLUG & VIRT_CABLE_PLUG_RSP mgmt codes */
struct virt_plug_params {
	__be32  status_hi;
	__be32  status_lo;
	__be32	fifo_hi;
	__be32	fifo_lo;
	__be32	fifo_len;
};

struct peer_work_params {
	union {
		struct virt_plug_params plug_req;
	};
};

/**
 * fwtty_peer: structure representing local & remote unit devices
 * @unit: unit child device of fw_device node
 * @serial: back pointer to associated fw_serial aggregate
 * @guid: unique 64-bit guid for this unit device
 * @generation: most recent bus generation
 * @node_id: most recent node_id
 * @speed: link speed of peer (0 = S100, 2 = S400, ... 5 = S3200)
 * @mgmt_addr: bus addr region to write mgmt packets to
 * @status_addr: bus addr register to write line status to
 * @fifo_addr: bus addr region to write serial output to
 * @fifo_len:  max length for single write to fifo_addr
 * @list: link for insertion into fw_serial's peer_list
 * @rcu: for deferring peer reclamation
 * @lock: spinlock to synchonize changes to state & port fields
 * @work: only one work item can be queued at any one time
 *        Note: pending work is canceled prior to removal, so this
 *        peer is valid for at least the lifetime of the work function
 * @work_params: parameter block for work functions
 * @timer: timer for resetting peer state if remote request times out
 * @state: current state
 * @connect: work item for auto-connecting
 * @connect_retries: # of connections already attempted
 * @port: associated tty_port (usable if state == FWSC_ATTACHED)
 */
struct fwtty_peer {
	struct fw_unit		*unit;
	struct fw_serial	*serial;
	u64			guid;
	int			generation;
	int			node_id;
	unsigned		speed;
	int			max_payload;
	u64			mgmt_addr;

	/* these are usable only if state == FWSC_ATTACHED */
	u64			status_addr;
	u64			fifo_addr;
	int			fifo_len;

	struct list_head	list;
	struct rcu_head		rcu;

	spinlock_t		lock;
	work_func_t		workfn;
	struct work_struct	work;
	struct peer_work_params work_params;
	struct timer_list	timer;
	int			state;
	struct delayed_work	connect;
	int			connect_retries;

	struct fwtty_port	*port;
};

#define to_peer(ptr, field)	(container_of(ptr, struct fwtty_peer, field))

/* state values for fwtty_peer.state field */
enum fwtty_peer_state {
	FWPS_GONE,
	FWPS_NOT_ATTACHED,
	FWPS_ATTACHED,
	FWPS_PLUG_PENDING,
	FWPS_PLUG_RESPONDING,
	FWPS_UNPLUG_PENDING,
	FWPS_UNPLUG_RESPONDING,

	FWPS_NO_MGMT_ADDR = -1,
};

#define CONNECT_RETRY_DELAY	HZ
#define MAX_CONNECT_RETRIES	10

/* must be holding peer lock for these state funclets */
static inline void peer_set_state(struct fwtty_peer *peer, int new)
{
	peer->state = new;
}

static inline struct fwtty_port *peer_revert_state(struct fwtty_peer *peer)
{
	struct fwtty_port *port = peer->port;

	peer->port = NULL;
	peer_set_state(peer, FWPS_NOT_ATTACHED);
	return port;
}

struct fwserial_mgmt_pkt {
	struct {
		__be16		len;
		__be16		code;
	} hdr;
	union {
		struct virt_plug_params plug_req;
		struct virt_plug_params plug_rsp;
	};
} __packed;

/* fwserial_mgmt_packet codes */
#define FWSC_RSP_OK			0x0000
#define FWSC_RSP_NACK			0x8000
#define FWSC_CODE_MASK			0x0fff

#define FWSC_VIRT_CABLE_PLUG		1
#define FWSC_VIRT_CABLE_UNPLUG		2
#define FWSC_VIRT_CABLE_PLUG_RSP	3
#define FWSC_VIRT_CABLE_UNPLUG_RSP	4

/* 1 min. plug timeout -- suitable for userland authorization */
#define VIRT_CABLE_PLUG_TIMEOUT		(60 * HZ)

struct stats {
	unsigned	xchars;
	unsigned	dropped;
	unsigned	tx_stall;
	unsigned	fifo_errs;
	unsigned	sent;
	unsigned	lost;
	unsigned	throttled;
	unsigned	reads[DISTRIBUTION_MAX_INDEX + 1];
	unsigned	writes[DISTRIBUTION_MAX_INDEX + 1];
	unsigned	txns[DISTRIBUTION_MAX_INDEX + 1];
	unsigned	unthrottle[DISTRIBUTION_MAX_INDEX + 1];
};

struct fwconsole_ops {
	void (*notify)(int code, void *data);
	void (*stats)(struct stats *stats, void *data);
	void (*proc_show)(struct seq_file *m, void *data);
};

/* codes for console ops notify */
#define FWCON_NOTIFY_ATTACH		1
#define FWCON_NOTIFY_DETACH		2

/**
 * fwtty_port: structure used to track/represent underlying tty_port
 * @port: underlying tty_port
 * @device: tty device
 * @index: index into port_table for this particular port
 *    note: minor = index + minor_start assigned by tty_alloc_driver()
 * @serial: back pointer to the containing fw_serial
 * @rx_handler: bus address handler for unique addr region used by remotes
 *              to communicate with this port. Every port uses
 *		fwtty_port_handler() for per port transactions.
 * @fwcon_ops: ops for attached fw_console (if any)
 * @con_data: private data for fw_console
 * @wait_tx: waitqueue for sleeping until writer/drain completes tx
 * @emit_breaks: delayed work responsible for generating breaks when the
 *               break line status is active
 * @cps : characters per second computed from the termios settings
 * @break_last: timestamp in jiffies from last emit_breaks
 * @hangup: work responsible for HUPing when carrier is dropped/lost
 * @mstatus: loose virtualization of LSR/MSR
 *         bits 15..0  correspond to TIOCM_* bits
 *         bits 19..16 reserved for mctrl
 *         bit 20      OOB_TX_THROTTLE
 *	   bits 23..21 reserved
 *         bits 31..24 correspond to UART_LSR_* bits
 * @lock: spinlock for protecting concurrent access to fields below it
 * @mctrl: loose virtualization of MCR
 *         bits 15..0  correspond to TIOCM_* bits
 *         bit 16      OOB_RX_THROTTLE
 *         bits 19..17 reserved
 *	   bits 31..20 reserved for mstatus
 * @drain: delayed work scheduled to ensure that writes are flushed.
 *         The work can race with the writer but concurrent sending is
 *         prevented with the IN_TX flag. Scheduled under lock to
 *         limit scheduling when fifo has just been drained.
 * @tx_fifo: fifo used to store & block-up writes for dma to remote
 * @max_payload: max bytes transmissable per dma (based on peer's max_payload)
 * @status_mask: UART_LSR_* bitmask significant to rx (based on termios)
 * @ignore_mask: UART_LSR_* bitmask of states to ignore (also based on termios)
 * @break_ctl: if set, port is 'sending break' to remote
 * @write_only: self-explanatory
 * @overrun: previous rx was lost (partially or completely)
 * @loopback: if set, port is in loopback mode
 * @flags: atomic bit flags
 *         bit 0: IN_TX - gate to allow only one cpu to send from the dma fifo
 *                        at a time.
 *         bit 1: STOP_TX - force tx to exit while sending
 * @peer: rcu-pointer to associated fwtty_peer (if attached)
 *        NULL if no peer attached
 * @icount: predefined statistics reported by the TIOCGICOUNT ioctl
 * @stats: additional statistics reported in /proc/tty/driver/firewire_serial
 */
struct fwtty_port {
	struct tty_port		   port;
	struct device		   *device;
	unsigned		   index;
	struct fw_serial	   *serial;
	struct fw_address_handler  rx_handler;

	struct fwconsole_ops	   *fwcon_ops;
	void			   *con_data;

	wait_queue_head_t	   wait_tx;
	struct delayed_work	   emit_breaks;
	unsigned		   cps;
	unsigned long		   break_last;

	struct work_struct	   hangup;

	unsigned		   mstatus;

	spinlock_t		   lock;
	unsigned		   mctrl;
	struct delayed_work	   drain;
	struct dma_fifo		   tx_fifo;
	int			   max_payload;
	unsigned		   status_mask;
	unsigned		   ignore_mask;
	unsigned		   break_ctl:1,
				   write_only:1,
				   overrun:1,
				   loopback:1;
	unsigned long		   flags;

	struct fwtty_peer __rcu	   *peer;

	struct async_icount	   icount;
	struct stats		   stats;
};

#define to_port(ptr, field)	(container_of(ptr, struct fwtty_port, field))

/* bit #s for flags field */
#define IN_TX                      0
#define STOP_TX                    1

/* bitmasks for special mctrl/mstatus bits */
#define OOB_RX_THROTTLE   0x00010000
#define MCTRL_RSRVD       0x000e0000
#define OOB_TX_THROTTLE   0x00100000
#define MSTATUS_RSRVD     0x00e00000

#define MCTRL_MASK        (TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 | TIOCM_OUT2 | \
			   TIOCM_LOOP | OOB_RX_THROTTLE | MCTRL_RSRVD)

/* XXX even every 1/50th secs. may be unnecessarily accurate */
/* delay in jiffies between brk emits */
#define FREQ_BREAKS        (HZ / 50)

/* Ports are allocated in blocks of num_ports for each fw_card */
#define MAX_CARD_PORTS           CONFIG_FWTTY_MAX_CARD_PORTS
#define MAX_TOTAL_PORTS          CONFIG_FWTTY_MAX_TOTAL_PORTS

/* tuning parameters */
#define FWTTY_PORT_TXFIFO_LEN	4096
#define FWTTY_PORT_MAX_PEND_DMA    8    /* costs a cache line per pend */
#define DRAIN_THRESHOLD         1024
#define MAX_ASYNC_PAYLOAD       4096    /* ohci-defined limit          */
#define WRITER_MINIMUM           128
/* TODO: how to set watermark to AR context size? see fwtty_rx() */
#define HIGH_WATERMARK         32768	/* AR context is 32K	       */

/*
 * Size of bus addr region above 4GB used per port as the recv addr
 * - must be at least as big as the MAX_ASYNC_PAYLOAD
 */
#define FWTTY_PORT_RXFIFO_LEN	MAX_ASYNC_PAYLOAD

/**
 * fw_serial: aggregate used to associate tty ports with specific fw_card
 * @card: fw_card associated with this fw_serial device (1:1 association)
 * @kref: reference-counted multi-port management allows delayed destroy
 * @self: local unit device as 'peer'. Not valid until local unit device
 *         is enumerated.
 * @list: link for insertion into fwserial_list
 * @peer_list: list of local & remote unit devices attached to this card
 * @ports: fixed array of tty_ports provided by this serial device
 */
struct fw_serial {
	struct fw_card	  *card;
	struct kref	  kref;

	struct dentry	  *debugfs;
	struct fwtty_peer *self;

	struct list_head  list;
	struct list_head  peer_list;

	struct fwtty_port *ports[MAX_CARD_PORTS];
};

#define to_serial(ptr, field)	(container_of(ptr, struct fw_serial, field))

#define TTY_DEV_NAME		    "fwtty"	/* ttyFW was taken           */
static const char tty_dev_name[] =  TTY_DEV_NAME;
static const char loop_dev_name[] = "fwloop";

extern struct tty_driver *fwtty_driver;

struct fwtty_port *fwtty_port_get(unsigned index);
void fwtty_port_put(struct fwtty_port *port);

static inline void fwtty_bind_console(struct fwtty_port *port,
				      struct fwconsole_ops *fwcon_ops,
				      void *data)
{
	port->con_data = data;
	port->fwcon_ops = fwcon_ops;
}

/*
 * Returns the max send async payload size in bytes based on the unit device
 * link speed. Self-limiting asynchronous bandwidth (via reducing the payload)
 * is not necessary and does not work, because
 *   1) asynchronous traffic will absorb all available bandwidth (less that
 *	being used for isochronous traffic)
 *   2) isochronous arbitration always wins.
 */
static inline int link_speed_to_max_payload(unsigned speed)
{
	/* Max async payload is 4096 - see IEEE 1394-2008 tables 6-4, 16-18 */
	return min(512 << speed, 4096);
}

#endif /* _FIREWIRE_FWSERIAL_H */

Privacy Policy