xref: /linux-6.15/include/linux/parport.h (revision 42e4eefb)
1 /*
2  * Any part of this program may be used in documents licensed under
3  * the GNU Free Documentation License, Version 1.1 or any later version
4  * published by the Free Software Foundation.
5  */
6 #ifndef _PARPORT_H_
7 #define _PARPORT_H_
8 
9 
10 #include <linux/jiffies.h>
11 #include <linux/proc_fs.h>
12 #include <linux/spinlock.h>
13 #include <linux/wait.h>
14 #include <linux/irqreturn.h>
15 #include <linux/semaphore.h>
16 #include <linux/device.h>
17 #include <asm/ptrace.h>
18 #include <uapi/linux/parport.h>
19 
20 /* Define this later. */
21 struct parport;
22 struct pardevice;
23 
24 struct pc_parport_state {
25 	unsigned int ctr;
26 	unsigned int ecr;
27 };
28 
29 struct ax_parport_state {
30 	unsigned int ctr;
31 	unsigned int ecr;
32 	unsigned int dcsr;
33 };
34 
35 /* used by both parport_amiga and parport_mfc3 */
36 struct amiga_parport_state {
37        unsigned char data;     /* ciaa.prb */
38        unsigned char datadir;  /* ciaa.ddrb */
39        unsigned char status;   /* ciab.pra & 7 */
40        unsigned char statusdir;/* ciab.ddrb & 7 */
41 };
42 
43 struct ax88796_parport_state {
44 	unsigned char cpr;
45 };
46 
47 struct ip32_parport_state {
48 	unsigned int dcr;
49 	unsigned int ecr;
50 };
51 
52 struct parport_state {
53 	union {
54 		struct pc_parport_state pc;
55 		/* ARC has no state. */
56 		struct ax_parport_state ax;
57 		struct amiga_parport_state amiga;
58 		struct ax88796_parport_state ax88796;
59 		/* Atari has not state. */
60 		struct ip32_parport_state ip32;
61 		void *misc;
62 	} u;
63 };
64 
65 struct parport_operations {
66 	/* IBM PC-style virtual registers. */
67 	void (*write_data)(struct parport *, unsigned char);
68 	unsigned char (*read_data)(struct parport *);
69 
70 	void (*write_control)(struct parport *, unsigned char);
71 	unsigned char (*read_control)(struct parport *);
72 	unsigned char (*frob_control)(struct parport *, unsigned char mask,
73 				      unsigned char val);
74 
75 	unsigned char (*read_status)(struct parport *);
76 
77 	/* IRQs. */
78 	void (*enable_irq)(struct parport *);
79 	void (*disable_irq)(struct parport *);
80 
81 	/* Data direction. */
82 	void (*data_forward) (struct parport *);
83 	void (*data_reverse) (struct parport *);
84 
85 	/* For core parport code. */
86 	void (*init_state)(struct pardevice *, struct parport_state *);
87 	void (*save_state)(struct parport *, struct parport_state *);
88 	void (*restore_state)(struct parport *, struct parport_state *);
89 
90 	/* Block read/write */
91 	size_t (*epp_write_data) (struct parport *port, const void *buf,
92 				  size_t len, int flags);
93 	size_t (*epp_read_data) (struct parport *port, void *buf, size_t len,
94 				 int flags);
95 	size_t (*epp_write_addr) (struct parport *port, const void *buf,
96 				  size_t len, int flags);
97 	size_t (*epp_read_addr) (struct parport *port, void *buf, size_t len,
98 				 int flags);
99 
100 	size_t (*ecp_write_data) (struct parport *port, const void *buf,
101 				  size_t len, int flags);
102 	size_t (*ecp_read_data) (struct parport *port, void *buf, size_t len,
103 				 int flags);
104 	size_t (*ecp_write_addr) (struct parport *port, const void *buf,
105 				  size_t len, int flags);
106 
107 	size_t (*compat_write_data) (struct parport *port, const void *buf,
108 				     size_t len, int flags);
109 	size_t (*nibble_read_data) (struct parport *port, void *buf,
110 				    size_t len, int flags);
111 	size_t (*byte_read_data) (struct parport *port, void *buf,
112 				  size_t len, int flags);
113 	struct module *owner;
114 };
115 
116 struct parport_device_info {
117 	parport_device_class class;
118 	const char *class_name;
119 	const char *mfr;
120 	const char *model;
121 	const char *cmdset;
122 	const char *description;
123 };
124 
125 /* Each device can have two callback functions:
126  *  1) a preemption function, called by the resource manager to request
127  *     that the driver relinquish control of the port.  The driver should
128  *     return zero if it agrees to release the port, and nonzero if it
129  *     refuses.  Do not call parport_release() - the kernel will do this
130  *     implicitly.
131  *
132  *  2) a wake-up function, called by the resource manager to tell drivers
133  *     that the port is available to be claimed.  If a driver wants to use
134  *     the port, it should call parport_claim() here.
135  */
136 
137 /* A parallel port device */
138 struct pardevice {
139 	const char *name;
140 	struct parport *port;
141 	int daisy;
142 	int (*preempt)(void *);
143 	void (*wakeup)(void *);
144 	void *private;
145 	void (*irq_func)(void *);
146 	unsigned int flags;
147 	struct pardevice *next;
148 	struct pardevice *prev;
149 	struct device dev;
150 	bool devmodel;
151 	struct parport_state *state;     /* saved status over preemption */
152 	wait_queue_head_t wait_q;
153 	unsigned long int time;
154 	unsigned long int timeslice;
155 	volatile long int timeout;
156 	unsigned long waiting;		 /* long req'd for set_bit --RR */
157 	struct pardevice *waitprev;
158 	struct pardevice *waitnext;
159 	void * sysctl_table;
160 };
161 
162 #define to_pardevice(n) container_of(n, struct pardevice, dev)
163 
164 /* IEEE1284 information */
165 
166 /* IEEE1284 phases. These are exposed to userland through ppdev IOCTL
167  * PP[GS]ETPHASE, so do not change existing values. */
168 enum ieee1284_phase {
169 	IEEE1284_PH_FWD_DATA,
170 	IEEE1284_PH_FWD_IDLE,
171 	IEEE1284_PH_TERMINATE,
172 	IEEE1284_PH_NEGOTIATION,
173 	IEEE1284_PH_HBUSY_DNA,
174 	IEEE1284_PH_REV_IDLE,
175 	IEEE1284_PH_HBUSY_DAVAIL,
176 	IEEE1284_PH_REV_DATA,
177 	IEEE1284_PH_ECP_SETUP,
178 	IEEE1284_PH_ECP_FWD_TO_REV,
179 	IEEE1284_PH_ECP_REV_TO_FWD,
180 	IEEE1284_PH_ECP_DIR_UNKNOWN,
181 };
182 struct ieee1284_info {
183 	int mode;
184 	volatile enum ieee1284_phase phase;
185 	struct semaphore irq;
186 };
187 
188 /* A parallel port */
189 struct parport {
190 	unsigned long base;	/* base address */
191 	unsigned long base_hi;  /* base address (hi - ECR) */
192 	unsigned int size;	/* IO extent */
193 	const char *name;
194 	unsigned int modes;
195 	int irq;		/* interrupt (or -1 for none) */
196 	int dma;
197 	int muxport;		/* which muxport (if any) this is */
198 	int portnum;		/* which physical parallel port (not mux) */
199 	struct device *dev;	/* Physical device associated with IO/DMA.
200 				 * This may unfortulately be null if the
201 				 * port has a legacy driver.
202 				 */
203 	struct device bus_dev;	/* to link with the bus */
204 	struct parport *physport;
205 				/* If this is a non-default mux
206 				   parport, i.e. we're a clone of a real
207 				   physical port, this is a pointer to that
208 				   port. The locking is only done in the
209 				   real port.  For a clone port, the
210 				   following structure members are
211 				   meaningless: devices, cad, muxsel,
212 				   waithead, waittail, flags, pdir,
213 				   dev, ieee1284, *_lock.
214 
215 				   It this is a default mux parport, or
216 				   there is no mux involved, this points to
217 				   ourself. */
218 
219 	struct pardevice *devices;
220 	struct pardevice *cad;	/* port owner */
221 	int daisy;		/* currently selected daisy addr */
222 	int muxsel;		/* currently selected mux port */
223 
224 	struct pardevice *waithead;
225 	struct pardevice *waittail;
226 
227 	struct list_head list;
228 	struct timer_list timer;
229 	unsigned int flags;
230 
231 	void *sysctl_table;
232 	struct parport_device_info probe_info[5]; /* 0-3 + non-IEEE1284.3 */
233 	struct ieee1284_info ieee1284;
234 
235 	struct parport_operations *ops;
236 	void *private_data;     /* for lowlevel driver */
237 
238 	int number;		/* port index - the `n' in `parportn' */
239 	spinlock_t pardevice_lock;
240 	spinlock_t waitlist_lock;
241 	rwlock_t cad_lock;
242 
243 	int spintime;
244 	atomic_t ref_count;
245 
246 	unsigned long devflags;
247 #define PARPORT_DEVPROC_REGISTERED	0
248 	struct pardevice *proc_device;	/* Currently register proc device */
249 
250 	struct list_head full_list;
251 	struct parport *slaves[3];
252 };
253 
254 #define to_parport_dev(n) container_of(n, struct parport, bus_dev)
255 
256 #define DEFAULT_SPIN_TIME 500 /* us */
257 
258 struct parport_driver {
259 	const char *name;
260 	void (*attach) (struct parport *);
261 	void (*detach) (struct parport *);
262 	void (*match_port)(struct parport *);
263 	int (*probe)(struct pardevice *);
264 	struct device_driver driver;
265 	bool devmodel;
266 	struct list_head list;
267 };
268 
269 #define to_parport_driver(n) container_of(n, struct parport_driver, driver)
270 
271 int parport_bus_init(void);
272 void parport_bus_exit(void);
273 
274 /* parport_register_port registers a new parallel port at the given
275    address (if one does not already exist) and returns a pointer to it.
276    This entails claiming the I/O region, IRQ and DMA.  NULL is returned
277    if initialisation fails. */
278 struct parport *parport_register_port(unsigned long base, int irq, int dma,
279 				      struct parport_operations *ops);
280 
281 /* Once a registered port is ready for high-level drivers to use, the
282    low-level driver that registered it should announce it.  This will
283    call the high-level drivers' attach() functions (after things like
284    determining the IEEE 1284.3 topology of the port and collecting
285    DeviceIDs). */
286 void parport_announce_port (struct parport *port);
287 
288 /* Unregister a port. */
289 extern void parport_remove_port(struct parport *port);
290 
291 /* Register a new high-level driver. */
292 
293 int __must_check __parport_register_driver(struct parport_driver *,
294 					   struct module *,
295 					   const char *mod_name);
296 /*
297  * parport_register_driver must be a macro so that KBUILD_MODNAME can
298  * be expanded
299  */
300 
301 /**
302  *	parport_register_driver - register a parallel port device driver
303  *	@driver: structure describing the driver
304  *
305  *	This can be called by a parallel port device driver in order
306  *	to receive notifications about ports being found in the
307  *	system, as well as ports no longer available.
308  *
309  *	If devmodel is true then the new device model is used
310  *	for registration.
311  *
312  *	The @driver structure is allocated by the caller and must not be
313  *	deallocated until after calling parport_unregister_driver().
314  *
315  *	If using the non device model:
316  *	The driver's attach() function may block.  The port that
317  *	attach() is given will be valid for the duration of the
318  *	callback, but if the driver wants to take a copy of the
319  *	pointer it must call parport_get_port() to do so.  Calling
320  *	parport_register_device() on that port will do this for you.
321  *
322  *	The driver's detach() function may block.  The port that
323  *	detach() is given will be valid for the duration of the
324  *	callback, but if the driver wants to take a copy of the
325  *	pointer it must call parport_get_port() to do so.
326  *
327  *
328  *	Returns 0 on success. The non device model will always succeeds.
329  *	but the new device model can fail and will return the error code.
330  **/
331 #define parport_register_driver(driver)             \
332 	__parport_register_driver(driver, THIS_MODULE, KBUILD_MODNAME)
333 
334 /* Unregister a high-level driver. */
335 extern void parport_unregister_driver (struct parport_driver *);
336 void parport_unregister_driver(struct parport_driver *);
337 
338 /* If parport_register_driver doesn't fit your needs, perhaps
339  * parport_find_xxx does. */
340 extern struct parport *parport_find_number (int);
341 extern struct parport *parport_find_base (unsigned long);
342 
343 /* generic irq handler, if it suits your needs */
344 extern irqreturn_t parport_irq_handler(int irq, void *dev_id);
345 
346 /* Reference counting for ports. */
347 extern struct parport *parport_get_port (struct parport *);
348 extern void parport_put_port (struct parport *);
349 void parport_del_port(struct parport *);
350 
351 struct pardev_cb {
352 	int (*preempt)(void *);
353 	void (*wakeup)(void *);
354 	void *private;
355 	void (*irq_func)(void *);
356 	unsigned int flags;
357 };
358 
359 /*
360  * parport_register_dev_model declares that a device is connected to a
361  * port, and tells the kernel all it needs to know.
362  */
363 struct pardevice *
364 parport_register_dev_model(struct parport *port, const char *name,
365 			   const struct pardev_cb *par_dev_cb, int cnt);
366 
367 /* parport_unregister unlinks a device from the chain. */
368 extern void parport_unregister_device(struct pardevice *dev);
369 
370 /* parport_claim tries to gain ownership of the port for a particular
371    driver.  This may fail (return non-zero) if another driver is busy.
372    If this driver has registered an interrupt handler, it will be
373    enabled.  */
374 extern int parport_claim(struct pardevice *dev);
375 
376 /* parport_claim_or_block is the same, but sleeps if the port cannot
377    be claimed.  Return value is 1 if it slept, 0 normally and -errno
378    on error.  */
379 extern int parport_claim_or_block(struct pardevice *dev);
380 
381 /* parport_release reverses a previous parport_claim.  This can never
382    fail, though the effects are undefined (except that they are bad)
383    if you didn't previously own the port.  Once you have released the
384    port you should make sure that neither your code nor the hardware
385    on the port tries to initiate any communication without first
386    re-claiming the port.  If you mess with the port state (enabling
387    ECP for example) you should clean up before releasing the port. */
388 
389 extern void parport_release(struct pardevice *dev);
390 
391 /**
392  * parport_yield - relinquish a parallel port temporarily
393  * @dev: a device on the parallel port
394  *
395  * This function relinquishes the port if it would be helpful to other
396  * drivers to do so.  Afterwards it tries to reclaim the port using
397  * parport_claim(), and the return value is the same as for
398  * parport_claim().  If it fails, the port is left unclaimed and it is
399  * the driver's responsibility to reclaim the port.
400  *
401  * The parport_yield() and parport_yield_blocking() functions are for
402  * marking points in the driver at which other drivers may claim the
403  * port and use their devices.  Yielding the port is similar to
404  * releasing it and reclaiming it, but is more efficient because no
405  * action is taken if there are no other devices needing the port.  In
406  * fact, nothing is done even if there are other devices waiting but
407  * the current device is still within its "timeslice".  The default
408  * timeslice is half a second, but it can be adjusted via the /proc
409  * interface.
410  **/
411 static __inline__ int parport_yield(struct pardevice *dev)
412 {
413 	unsigned long int timeslip = (jiffies - dev->time);
414 	if ((dev->port->waithead == NULL) || (timeslip < dev->timeslice))
415 		return 0;
416 	parport_release(dev);
417 	return parport_claim(dev);
418 }
419 
420 /**
421  * parport_yield_blocking - relinquish a parallel port temporarily
422  * @dev: a device on the parallel port
423  *
424  * This function relinquishes the port if it would be helpful to other
425  * drivers to do so.  Afterwards it tries to reclaim the port using
426  * parport_claim_or_block(), and the return value is the same as for
427  * parport_claim_or_block().
428  **/
429 static __inline__ int parport_yield_blocking(struct pardevice *dev)
430 {
431 	unsigned long int timeslip = (jiffies - dev->time);
432 	if ((dev->port->waithead == NULL) || (timeslip < dev->timeslice))
433 		return 0;
434 	parport_release(dev);
435 	return parport_claim_or_block(dev);
436 }
437 
438 /* Flags used to identify what a device does. */
439 #define PARPORT_DEV_TRAN		0	/* WARNING !! DEPRECATED !! */
440 #define PARPORT_DEV_LURK		(1<<0)	/* WARNING !! DEPRECATED !! */
441 #define PARPORT_DEV_EXCL		(1<<1)	/* Need exclusive access. */
442 
443 #define PARPORT_FLAG_EXCL		(1<<1)	/* EXCL driver registered. */
444 
445 /* IEEE1284 functions */
446 extern void parport_ieee1284_interrupt (void *);
447 extern int parport_negotiate (struct parport *, int mode);
448 extern ssize_t parport_write (struct parport *, const void *buf, size_t len);
449 extern ssize_t parport_read (struct parport *, void *buf, size_t len);
450 
451 #define PARPORT_INACTIVITY_O_NONBLOCK 1
452 extern long parport_set_timeout (struct pardevice *, long inactivity);
453 
454 extern int parport_wait_event (struct parport *, long timeout);
455 extern int parport_wait_peripheral (struct parport *port,
456 				    unsigned char mask,
457 				    unsigned char val);
458 extern int parport_poll_peripheral (struct parport *port,
459 				    unsigned char mask,
460 				    unsigned char val,
461 				    int usec);
462 
463 /* For architectural drivers */
464 extern size_t parport_ieee1284_write_compat (struct parport *,
465 					     const void *, size_t, int);
466 extern size_t parport_ieee1284_read_nibble (struct parport *,
467 					    void *, size_t, int);
468 extern size_t parport_ieee1284_read_byte (struct parport *,
469 					  void *, size_t, int);
470 extern size_t parport_ieee1284_ecp_read_data (struct parport *,
471 					      void *, size_t, int);
472 extern size_t parport_ieee1284_ecp_write_data (struct parport *,
473 					       const void *, size_t, int);
474 extern size_t parport_ieee1284_ecp_write_addr (struct parport *,
475 					       const void *, size_t, int);
476 extern size_t parport_ieee1284_epp_write_data (struct parport *,
477 					       const void *, size_t, int);
478 extern size_t parport_ieee1284_epp_read_data (struct parport *,
479 					      void *, size_t, int);
480 extern size_t parport_ieee1284_epp_write_addr (struct parport *,
481 					       const void *, size_t, int);
482 extern size_t parport_ieee1284_epp_read_addr (struct parport *,
483 					      void *, size_t, int);
484 
485 /* IEEE1284.3 functions */
486 #define daisy_dev_name "Device ID probe"
487 extern int parport_daisy_init (struct parport *port);
488 extern void parport_daisy_fini (struct parport *port);
489 extern struct pardevice *parport_open (int devnum, const char *name);
490 extern void parport_close (struct pardevice *dev);
491 extern ssize_t parport_device_id (int devnum, char *buffer, size_t len);
492 extern void parport_daisy_deselect_all (struct parport *port);
493 extern int parport_daisy_select (struct parport *port, int daisy, int mode);
494 
495 /* Lowlevel drivers _can_ call this support function to handle irqs.  */
496 static inline void parport_generic_irq(struct parport *port)
497 {
498 	parport_ieee1284_interrupt (port);
499 	read_lock(&port->cad_lock);
500 	if (port->cad && port->cad->irq_func)
501 		port->cad->irq_func(port->cad->private);
502 	read_unlock(&port->cad_lock);
503 }
504 
505 /* Prototypes from parport_procfs */
506 extern int parport_proc_register(struct parport *pp);
507 extern int parport_proc_unregister(struct parport *pp);
508 extern int parport_device_proc_register(struct pardevice *device);
509 extern int parport_device_proc_unregister(struct pardevice *device);
510 
511 /* If PC hardware is the only type supported, we can optimise a bit.  */
512 #if !defined(CONFIG_PARPORT_NOT_PC)
513 
514 #include <linux/parport_pc.h>
515 #define parport_write_data(p,x)            parport_pc_write_data(p,x)
516 #define parport_read_data(p)               parport_pc_read_data(p)
517 #define parport_write_control(p,x)         parport_pc_write_control(p,x)
518 #define parport_read_control(p)            parport_pc_read_control(p)
519 #define parport_frob_control(p,m,v)        parport_pc_frob_control(p,m,v)
520 #define parport_read_status(p)             parport_pc_read_status(p)
521 #define parport_enable_irq(p)              parport_pc_enable_irq(p)
522 #define parport_disable_irq(p)             parport_pc_disable_irq(p)
523 #define parport_data_forward(p)            parport_pc_data_forward(p)
524 #define parport_data_reverse(p)            parport_pc_data_reverse(p)
525 
526 #else  /*  !CONFIG_PARPORT_NOT_PC  */
527 
528 /* Generic operations vector through the dispatch table. */
529 #define parport_write_data(p,x)            (p)->ops->write_data(p,x)
530 #define parport_read_data(p)               (p)->ops->read_data(p)
531 #define parport_write_control(p,x)         (p)->ops->write_control(p,x)
532 #define parport_read_control(p)            (p)->ops->read_control(p)
533 #define parport_frob_control(p,m,v)        (p)->ops->frob_control(p,m,v)
534 #define parport_read_status(p)             (p)->ops->read_status(p)
535 #define parport_enable_irq(p)              (p)->ops->enable_irq(p)
536 #define parport_disable_irq(p)             (p)->ops->disable_irq(p)
537 #define parport_data_forward(p)            (p)->ops->data_forward(p)
538 #define parport_data_reverse(p)            (p)->ops->data_reverse(p)
539 
540 #endif /*  !CONFIG_PARPORT_NOT_PC  */
541 
542 extern unsigned long parport_default_timeslice;
543 extern int parport_default_spintime;
544 
545 #endif /* _PARPORT_H_ */
546