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1 /*
2  *  pti.c - PTI driver for cJTAG data extration
3  *
4  *  Copyright (C) Intel 2010
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  *
15  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
16  *
17  * The PTI (Parallel Trace Interface) driver directs trace data routed from
18  * various parts in the system out through the Intel Penwell PTI port and
19  * out of the mobile device for analysis with a debugging tool
20  * (Lauterbach, Fido). This is part of a solution for the MIPI P1149.7,
21  * compact JTAG, standard.
22  */
23 
24 #include <linux/init.h>
25 #include <linux/sched.h>
26 #include <linux/interrupt.h>
27 #include <linux/console.h>
28 #include <linux/kernel.h>
29 #include <linux/module.h>
30 #include <linux/tty.h>
31 #include <linux/tty_driver.h>
32 #include <linux/pci.h>
33 #include <linux/mutex.h>
34 #include <linux/miscdevice.h>
35 #include <linux/pti.h>
36 #include <linux/slab.h>
37 #include <linux/uaccess.h>
38 
39 #define DRIVERNAME		"pti"
40 #define PCINAME			"pciPTI"
41 #define TTYNAME			"ttyPTI"
42 #define CHARNAME		"pti"
43 #define PTITTY_MINOR_START	0
44 #define PTITTY_MINOR_NUM	2
45 #define MAX_APP_IDS		16   /* 128 channel ids / u8 bit size */
46 #define MAX_OS_IDS		16   /* 128 channel ids / u8 bit size */
47 #define MAX_MODEM_IDS		16   /* 128 channel ids / u8 bit size */
48 #define MODEM_BASE_ID		71   /* modem master ID address    */
49 #define CONTROL_ID		72   /* control master ID address  */
50 #define CONSOLE_ID		73   /* console master ID address  */
51 #define OS_BASE_ID		74   /* base OS master ID address  */
52 #define APP_BASE_ID		80   /* base App master ID address */
53 #define CONTROL_FRAME_LEN	32   /* PTI control frame maximum size */
54 #define USER_COPY_SIZE		8192 /* 8Kb buffer for user space copy */
55 #define APERTURE_14		0x3800000 /* offset to first OS write addr */
56 #define APERTURE_LEN		0x400000  /* address length */
57 
58 struct pti_tty {
59 	struct pti_masterchannel *mc;
60 };
61 
62 struct pti_dev {
63 	struct tty_port port;
64 	unsigned long pti_addr;
65 	unsigned long aperture_base;
66 	void __iomem *pti_ioaddr;
67 	u8 ia_app[MAX_APP_IDS];
68 	u8 ia_os[MAX_OS_IDS];
69 	u8 ia_modem[MAX_MODEM_IDS];
70 };
71 
72 /*
73  * This protects access to ia_app, ia_os, and ia_modem,
74  * which keeps track of channels allocated in
75  * an aperture write id.
76  */
77 static DEFINE_MUTEX(alloclock);
78 
79 static struct pci_device_id pci_ids[] __devinitconst = {
80 		{PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x82B)},
81 		{0}
82 };
83 
84 static struct tty_driver *pti_tty_driver;
85 static struct pti_dev *drv_data;
86 
87 static unsigned int pti_console_channel;
88 static unsigned int pti_control_channel;
89 
90 /**
91  *  pti_write_to_aperture()- The private write function to PTI HW.
92  *
93  *  @mc: The 'aperture'. It's part of a write address that holds
94  *       a master and channel ID.
95  *  @buf: Data being written to the HW that will ultimately be seen
96  *        in a debugging tool (Fido, Lauterbach).
97  *  @len: Size of buffer.
98  *
99  *  Since each aperture is specified by a unique
100  *  master/channel ID, no two processes will be writing
101  *  to the same aperture at the same time so no lock is required. The
102  *  PTI-Output agent will send these out in the order that they arrived, and
103  *  thus, it will intermix these messages. The debug tool can then later
104  *  regroup the appropriate message segments together reconstituting each
105  *  message.
106  */
pti_write_to_aperture(struct pti_masterchannel * mc,u8 * buf,int len)107 static void pti_write_to_aperture(struct pti_masterchannel *mc,
108 				  u8 *buf,
109 				  int len)
110 {
111 	int dwordcnt;
112 	int final;
113 	int i;
114 	u32 ptiword;
115 	u32 __iomem *aperture;
116 	u8 *p = buf;
117 
118 	/*
119 	 * calculate the aperture offset from the base using the master and
120 	 * channel id's.
121 	 */
122 	aperture = drv_data->pti_ioaddr + (mc->master << 15)
123 		+ (mc->channel << 8);
124 
125 	dwordcnt = len >> 2;
126 	final = len - (dwordcnt << 2);	    /* final = trailing bytes    */
127 	if (final == 0 && dwordcnt != 0) {  /* always need a final dword */
128 		final += 4;
129 		dwordcnt--;
130 	}
131 
132 	for (i = 0; i < dwordcnt; i++) {
133 		ptiword = be32_to_cpu(*(u32 *)p);
134 		p += 4;
135 		iowrite32(ptiword, aperture);
136 	}
137 
138 	aperture += PTI_LASTDWORD_DTS;	/* adding DTS signals that is EOM */
139 
140 	ptiword = 0;
141 	for (i = 0; i < final; i++)
142 		ptiword |= *p++ << (24-(8*i));
143 
144 	iowrite32(ptiword, aperture);
145 	return;
146 }
147 
148 /**
149  *  pti_control_frame_built_and_sent()- control frame build and send function.
150  *
151  *  @mc:          The master / channel structure on which the function
152  *                built a control frame.
153  *  @thread_name: The thread name associated with the master / channel or
154  *                'NULL' if using the 'current' global variable.
155  *
156  *  To be able to post process the PTI contents on host side, a control frame
157  *  is added before sending any PTI content. So the host side knows on
158  *  each PTI frame the name of the thread using a dedicated master / channel.
159  *  The thread name is retrieved from 'current' global variable if 'thread_name'
160  *  is 'NULL', else it is retrieved from 'thread_name' parameter.
161  *  This function builds this frame and sends it to a master ID CONTROL_ID.
162  *  The overhead is only 32 bytes since the driver only writes to HW
163  *  in 32 byte chunks.
164  */
pti_control_frame_built_and_sent(struct pti_masterchannel * mc,const char * thread_name)165 static void pti_control_frame_built_and_sent(struct pti_masterchannel *mc,
166 					     const char *thread_name)
167 {
168 	/*
169 	 * Since we access the comm member in current's task_struct, we only
170 	 * need to be as large as what 'comm' in that structure is.
171 	 */
172 	char comm[TASK_COMM_LEN];
173 	struct pti_masterchannel mccontrol = {.master = CONTROL_ID,
174 					      .channel = 0};
175 	const char *thread_name_p;
176 	const char *control_format = "%3d %3d %s";
177 	u8 control_frame[CONTROL_FRAME_LEN];
178 
179 	if (!thread_name) {
180 		if (!in_interrupt())
181 			get_task_comm(comm, current);
182 		else
183 			strncpy(comm, "Interrupt", TASK_COMM_LEN);
184 
185 		/* Absolutely ensure our buffer is zero terminated. */
186 		comm[TASK_COMM_LEN-1] = 0;
187 		thread_name_p = comm;
188 	} else {
189 		thread_name_p = thread_name;
190 	}
191 
192 	mccontrol.channel = pti_control_channel;
193 	pti_control_channel = (pti_control_channel + 1) & 0x7f;
194 
195 	snprintf(control_frame, CONTROL_FRAME_LEN, control_format, mc->master,
196 		mc->channel, thread_name_p);
197 	pti_write_to_aperture(&mccontrol, control_frame, strlen(control_frame));
198 }
199 
200 /**
201  *  pti_write_full_frame_to_aperture()- high level function to
202  *					write to PTI.
203  *
204  *  @mc:  The 'aperture'. It's part of a write address that holds
205  *        a master and channel ID.
206  *  @buf: Data being written to the HW that will ultimately be seen
207  *        in a debugging tool (Fido, Lauterbach).
208  *  @len: Size of buffer.
209  *
210  *  All threads sending data (either console, user space application, ...)
211  *  are calling the high level function to write to PTI meaning that it is
212  *  possible to add a control frame before sending the content.
213  */
pti_write_full_frame_to_aperture(struct pti_masterchannel * mc,const unsigned char * buf,int len)214 static void pti_write_full_frame_to_aperture(struct pti_masterchannel *mc,
215 						const unsigned char *buf,
216 						int len)
217 {
218 	pti_control_frame_built_and_sent(mc, NULL);
219 	pti_write_to_aperture(mc, (u8 *)buf, len);
220 }
221 
222 /**
223  * get_id()- Allocate a master and channel ID.
224  *
225  * @id_array:    an array of bits representing what channel
226  *               id's are allocated for writing.
227  * @max_ids:     The max amount of available write IDs to use.
228  * @base_id:     The starting SW channel ID, based on the Intel
229  *               PTI arch.
230  * @thread_name: The thread name associated with the master / channel or
231  *               'NULL' if using the 'current' global variable.
232  *
233  * Returns:
234  *	pti_masterchannel struct with master, channel ID address
235  *	0 for error
236  *
237  * Each bit in the arrays ia_app and ia_os correspond to a master and
238  * channel id. The bit is one if the id is taken and 0 if free. For
239  * every master there are 128 channel id's.
240  */
get_id(u8 * id_array,int max_ids,int base_id,const char * thread_name)241 static struct pti_masterchannel *get_id(u8 *id_array,
242 					int max_ids,
243 					int base_id,
244 					const char *thread_name)
245 {
246 	struct pti_masterchannel *mc;
247 	int i, j, mask;
248 
249 	mc = kmalloc(sizeof(struct pti_masterchannel), GFP_KERNEL);
250 	if (mc == NULL)
251 		return NULL;
252 
253 	/* look for a byte with a free bit */
254 	for (i = 0; i < max_ids; i++)
255 		if (id_array[i] != 0xff)
256 			break;
257 	if (i == max_ids) {
258 		kfree(mc);
259 		return NULL;
260 	}
261 	/* find the bit in the 128 possible channel opportunities */
262 	mask = 0x80;
263 	for (j = 0; j < 8; j++) {
264 		if ((id_array[i] & mask) == 0)
265 			break;
266 		mask >>= 1;
267 	}
268 
269 	/* grab it */
270 	id_array[i] |= mask;
271 	mc->master  = base_id;
272 	mc->channel = ((i & 0xf)<<3) + j;
273 	/* write new master Id / channel Id allocation to channel control */
274 	pti_control_frame_built_and_sent(mc, thread_name);
275 	return mc;
276 }
277 
278 /*
279  * The following three functions:
280  * pti_request_mastercahannel(), mipi_release_masterchannel()
281  * and pti_writedata() are an API for other kernel drivers to
282  * access PTI.
283  */
284 
285 /**
286  * pti_request_masterchannel()- Kernel API function used to allocate
287  *				a master, channel ID address
288  *				to write to PTI HW.
289  *
290  * @type:        0- request Application  master, channel aperture ID
291  *                  write address.
292  *               1- request OS master, channel aperture ID write
293  *                  address.
294  *               2- request Modem master, channel aperture ID
295  *                  write address.
296  *               Other values, error.
297  * @thread_name: The thread name associated with the master / channel or
298  *               'NULL' if using the 'current' global variable.
299  *
300  * Returns:
301  *	pti_masterchannel struct
302  *	0 for error
303  */
pti_request_masterchannel(u8 type,const char * thread_name)304 struct pti_masterchannel *pti_request_masterchannel(u8 type,
305 						    const char *thread_name)
306 {
307 	struct pti_masterchannel *mc;
308 
309 	mutex_lock(&alloclock);
310 
311 	switch (type) {
312 
313 	case 0:
314 		mc = get_id(drv_data->ia_app, MAX_APP_IDS,
315 			    APP_BASE_ID, thread_name);
316 		break;
317 
318 	case 1:
319 		mc = get_id(drv_data->ia_os, MAX_OS_IDS,
320 			    OS_BASE_ID, thread_name);
321 		break;
322 
323 	case 2:
324 		mc = get_id(drv_data->ia_modem, MAX_MODEM_IDS,
325 			    MODEM_BASE_ID, thread_name);
326 		break;
327 	default:
328 		mc = NULL;
329 	}
330 
331 	mutex_unlock(&alloclock);
332 	return mc;
333 }
334 EXPORT_SYMBOL_GPL(pti_request_masterchannel);
335 
336 /**
337  * pti_release_masterchannel()- Kernel API function used to release
338  *				a master, channel ID address
339  *				used to write to PTI HW.
340  *
341  * @mc: master, channel apeture ID address to be released.  This
342  *      will de-allocate the structure via kfree().
343  */
pti_release_masterchannel(struct pti_masterchannel * mc)344 void pti_release_masterchannel(struct pti_masterchannel *mc)
345 {
346 	u8 master, channel, i;
347 
348 	mutex_lock(&alloclock);
349 
350 	if (mc) {
351 		master = mc->master;
352 		channel = mc->channel;
353 
354 		if (master == APP_BASE_ID) {
355 			i = channel >> 3;
356 			drv_data->ia_app[i] &=  ~(0x80>>(channel & 0x7));
357 		} else if (master == OS_BASE_ID) {
358 			i = channel >> 3;
359 			drv_data->ia_os[i] &= ~(0x80>>(channel & 0x7));
360 		} else {
361 			i = channel >> 3;
362 			drv_data->ia_modem[i] &= ~(0x80>>(channel & 0x7));
363 		}
364 
365 		kfree(mc);
366 	}
367 
368 	mutex_unlock(&alloclock);
369 }
370 EXPORT_SYMBOL_GPL(pti_release_masterchannel);
371 
372 /**
373  * pti_writedata()- Kernel API function used to write trace
374  *                  debugging data to PTI HW.
375  *
376  * @mc:    Master, channel aperture ID address to write to.
377  *         Null value will return with no write occurring.
378  * @buf:   Trace debuging data to write to the PTI HW.
379  *         Null value will return with no write occurring.
380  * @count: Size of buf. Value of 0 or a negative number will
381  *         return with no write occuring.
382  */
pti_writedata(struct pti_masterchannel * mc,u8 * buf,int count)383 void pti_writedata(struct pti_masterchannel *mc, u8 *buf, int count)
384 {
385 	/*
386 	 * since this function is exported, this is treated like an
387 	 * API function, thus, all parameters should
388 	 * be checked for validity.
389 	 */
390 	if ((mc != NULL) && (buf != NULL) && (count > 0))
391 		pti_write_to_aperture(mc, buf, count);
392 	return;
393 }
394 EXPORT_SYMBOL_GPL(pti_writedata);
395 
396 /**
397  * pti_pci_remove()- Driver exit method to remove PTI from
398  *		   PCI bus.
399  * @pdev: variable containing pci info of PTI.
400  */
pti_pci_remove(struct pci_dev * pdev)401 static void __devexit pti_pci_remove(struct pci_dev *pdev)
402 {
403 	struct pti_dev *drv_data;
404 
405 	drv_data = pci_get_drvdata(pdev);
406 	if (drv_data != NULL) {
407 		pci_iounmap(pdev, drv_data->pti_ioaddr);
408 		pci_set_drvdata(pdev, NULL);
409 		kfree(drv_data);
410 		pci_release_region(pdev, 1);
411 		pci_disable_device(pdev);
412 	}
413 }
414 
415 /*
416  * for the tty_driver_*() basic function descriptions, see tty_driver.h.
417  * Specific header comments made for PTI-related specifics.
418  */
419 
420 /**
421  * pti_tty_driver_open()- Open an Application master, channel aperture
422  * ID to the PTI device via tty device.
423  *
424  * @tty: tty interface.
425  * @filp: filp interface pased to tty_port_open() call.
426  *
427  * Returns:
428  *	int, 0 for success
429  *	otherwise, fail value
430  *
431  * The main purpose of using the tty device interface is for
432  * each tty port to have a unique PTI write aperture.  In an
433  * example use case, ttyPTI0 gets syslogd and an APP aperture
434  * ID and ttyPTI1 is where the n_tracesink ldisc hooks to route
435  * modem messages into PTI.  Modem trace data does not have to
436  * go to ttyPTI1, but ttyPTI0 and ttyPTI1 do need to be distinct
437  * master IDs.  These messages go through the PTI HW and out of
438  * the handheld platform and to the Fido/Lauterbach device.
439  */
pti_tty_driver_open(struct tty_struct * tty,struct file * filp)440 static int pti_tty_driver_open(struct tty_struct *tty, struct file *filp)
441 {
442 	/*
443 	 * we actually want to allocate a new channel per open, per
444 	 * system arch.  HW gives more than plenty channels for a single
445 	 * system task to have its own channel to write trace data. This
446 	 * also removes a locking requirement for the actual write
447 	 * procedure.
448 	 */
449 	return tty_port_open(&drv_data->port, tty, filp);
450 }
451 
452 /**
453  * pti_tty_driver_close()- close tty device and release Application
454  * master, channel aperture ID to the PTI device via tty device.
455  *
456  * @tty: tty interface.
457  * @filp: filp interface pased to tty_port_close() call.
458  *
459  * The main purpose of using the tty device interface is to route
460  * syslog daemon messages to the PTI HW and out of the handheld platform
461  * and to the Fido/Lauterbach device.
462  */
pti_tty_driver_close(struct tty_struct * tty,struct file * filp)463 static void pti_tty_driver_close(struct tty_struct *tty, struct file *filp)
464 {
465 	tty_port_close(&drv_data->port, tty, filp);
466 }
467 
468 /**
469  * pti_tty_install()- Used to set up specific master-channels
470  *		      to tty ports for organizational purposes when
471  *		      tracing viewed from debuging tools.
472  *
473  * @driver: tty driver information.
474  * @tty: tty struct containing pti information.
475  *
476  * Returns:
477  *	0 for success
478  *	otherwise, error
479  */
pti_tty_install(struct tty_driver * driver,struct tty_struct * tty)480 static int pti_tty_install(struct tty_driver *driver, struct tty_struct *tty)
481 {
482 	int idx = tty->index;
483 	struct pti_tty *pti_tty_data;
484 	int ret = tty_standard_install(driver, tty);
485 
486 	if (ret == 0) {
487 		pti_tty_data = kmalloc(sizeof(struct pti_tty), GFP_KERNEL);
488 		if (pti_tty_data == NULL)
489 			return -ENOMEM;
490 
491 		if (idx == PTITTY_MINOR_START)
492 			pti_tty_data->mc = pti_request_masterchannel(0, NULL);
493 		else
494 			pti_tty_data->mc = pti_request_masterchannel(2, NULL);
495 
496 		if (pti_tty_data->mc == NULL) {
497 			kfree(pti_tty_data);
498 			return -ENXIO;
499 		}
500 		tty->driver_data = pti_tty_data;
501 	}
502 
503 	return ret;
504 }
505 
506 /**
507  * pti_tty_cleanup()- Used to de-allocate master-channel resources
508  *		      tied to tty's of this driver.
509  *
510  * @tty: tty struct containing pti information.
511  */
pti_tty_cleanup(struct tty_struct * tty)512 static void pti_tty_cleanup(struct tty_struct *tty)
513 {
514 	struct pti_tty *pti_tty_data = tty->driver_data;
515 	if (pti_tty_data == NULL)
516 		return;
517 	pti_release_masterchannel(pti_tty_data->mc);
518 	kfree(pti_tty_data);
519 	tty->driver_data = NULL;
520 }
521 
522 /**
523  * pti_tty_driver_write()-  Write trace debugging data through the char
524  * interface to the PTI HW.  Part of the misc device implementation.
525  *
526  * @filp: Contains private data which is used to obtain
527  *        master, channel write ID.
528  * @data: trace data to be written.
529  * @len:  # of byte to write.
530  *
531  * Returns:
532  *	int, # of bytes written
533  *	otherwise, error
534  */
pti_tty_driver_write(struct tty_struct * tty,const unsigned char * buf,int len)535 static int pti_tty_driver_write(struct tty_struct *tty,
536 	const unsigned char *buf, int len)
537 {
538 	struct pti_tty *pti_tty_data = tty->driver_data;
539 	if ((pti_tty_data != NULL) && (pti_tty_data->mc != NULL)) {
540 		pti_write_to_aperture(pti_tty_data->mc, (u8 *)buf, len);
541 		return len;
542 	}
543 	/*
544 	 * we can't write to the pti hardware if the private driver_data
545 	 * and the mc address is not there.
546 	 */
547 	else
548 		return -EFAULT;
549 }
550 
551 /**
552  * pti_tty_write_room()- Always returns 2048.
553  *
554  * @tty: contains tty info of the pti driver.
555  */
pti_tty_write_room(struct tty_struct * tty)556 static int pti_tty_write_room(struct tty_struct *tty)
557 {
558 	return 2048;
559 }
560 
561 /**
562  * pti_char_open()- Open an Application master, channel aperture
563  * ID to the PTI device. Part of the misc device implementation.
564  *
565  * @inode: not used.
566  * @filp:  Output- will have a masterchannel struct set containing
567  *                 the allocated application PTI aperture write address.
568  *
569  * Returns:
570  *	int, 0 for success
571  *	otherwise, a fail value
572  */
pti_char_open(struct inode * inode,struct file * filp)573 static int pti_char_open(struct inode *inode, struct file *filp)
574 {
575 	struct pti_masterchannel *mc;
576 
577 	/*
578 	 * We really do want to fail immediately if
579 	 * pti_request_masterchannel() fails,
580 	 * before assigning the value to filp->private_data.
581 	 * Slightly easier to debug if this driver needs debugging.
582 	 */
583 	mc = pti_request_masterchannel(0, NULL);
584 	if (mc == NULL)
585 		return -ENOMEM;
586 	filp->private_data = mc;
587 	return 0;
588 }
589 
590 /**
591  * pti_char_release()-  Close a char channel to the PTI device. Part
592  * of the misc device implementation.
593  *
594  * @inode: Not used in this implementaiton.
595  * @filp:  Contains private_data that contains the master, channel
596  *         ID to be released by the PTI device.
597  *
598  * Returns:
599  *	always 0
600  */
pti_char_release(struct inode * inode,struct file * filp)601 static int pti_char_release(struct inode *inode, struct file *filp)
602 {
603 	pti_release_masterchannel(filp->private_data);
604 	filp->private_data = NULL;
605 	return 0;
606 }
607 
608 /**
609  * pti_char_write()-  Write trace debugging data through the char
610  * interface to the PTI HW.  Part of the misc device implementation.
611  *
612  * @filp:  Contains private data which is used to obtain
613  *         master, channel write ID.
614  * @data:  trace data to be written.
615  * @len:   # of byte to write.
616  * @ppose: Not used in this function implementation.
617  *
618  * Returns:
619  *	int, # of bytes written
620  *	otherwise, error value
621  *
622  * Notes: From side discussions with Alan Cox and experimenting
623  * with PTI debug HW like Nokia's Fido box and Lauterbach
624  * devices, 8192 byte write buffer used by USER_COPY_SIZE was
625  * deemed an appropriate size for this type of usage with
626  * debugging HW.
627  */
pti_char_write(struct file * filp,const char __user * data,size_t len,loff_t * ppose)628 static ssize_t pti_char_write(struct file *filp, const char __user *data,
629 			      size_t len, loff_t *ppose)
630 {
631 	struct pti_masterchannel *mc;
632 	void *kbuf;
633 	const char __user *tmp;
634 	size_t size = USER_COPY_SIZE;
635 	size_t n = 0;
636 
637 	tmp = data;
638 	mc = filp->private_data;
639 
640 	kbuf = kmalloc(size, GFP_KERNEL);
641 	if (kbuf == NULL)  {
642 		pr_err("%s(%d): buf allocation failed\n",
643 			__func__, __LINE__);
644 		return -ENOMEM;
645 	}
646 
647 	do {
648 		if (len - n > USER_COPY_SIZE)
649 			size = USER_COPY_SIZE;
650 		else
651 			size = len - n;
652 
653 		if (copy_from_user(kbuf, tmp, size)) {
654 			kfree(kbuf);
655 			return n ? n : -EFAULT;
656 		}
657 
658 		pti_write_to_aperture(mc, kbuf, size);
659 		n  += size;
660 		tmp += size;
661 
662 	} while (len > n);
663 
664 	kfree(kbuf);
665 	return len;
666 }
667 
668 static const struct tty_operations pti_tty_driver_ops = {
669 	.open		= pti_tty_driver_open,
670 	.close		= pti_tty_driver_close,
671 	.write		= pti_tty_driver_write,
672 	.write_room	= pti_tty_write_room,
673 	.install	= pti_tty_install,
674 	.cleanup	= pti_tty_cleanup
675 };
676 
677 static const struct file_operations pti_char_driver_ops = {
678 	.owner		= THIS_MODULE,
679 	.write		= pti_char_write,
680 	.open		= pti_char_open,
681 	.release	= pti_char_release,
682 };
683 
684 static struct miscdevice pti_char_driver = {
685 	.minor		= MISC_DYNAMIC_MINOR,
686 	.name		= CHARNAME,
687 	.fops		= &pti_char_driver_ops
688 };
689 
690 /**
691  * pti_console_write()-  Write to the console that has been acquired.
692  *
693  * @c:   Not used in this implementaiton.
694  * @buf: Data to be written.
695  * @len: Length of buf.
696  */
pti_console_write(struct console * c,const char * buf,unsigned len)697 static void pti_console_write(struct console *c, const char *buf, unsigned len)
698 {
699 	static struct pti_masterchannel mc = {.master  = CONSOLE_ID,
700 					      .channel = 0};
701 
702 	mc.channel = pti_console_channel;
703 	pti_console_channel = (pti_console_channel + 1) & 0x7f;
704 
705 	pti_write_full_frame_to_aperture(&mc, buf, len);
706 }
707 
708 /**
709  * pti_console_device()-  Return the driver tty structure and set the
710  *			  associated index implementation.
711  *
712  * @c:     Console device of the driver.
713  * @index: index associated with c.
714  *
715  * Returns:
716  *	always value of pti_tty_driver structure when this function
717  *	is called.
718  */
pti_console_device(struct console * c,int * index)719 static struct tty_driver *pti_console_device(struct console *c, int *index)
720 {
721 	*index = c->index;
722 	return pti_tty_driver;
723 }
724 
725 /**
726  * pti_console_setup()-  Initialize console variables used by the driver.
727  *
728  * @c:     Not used.
729  * @opts:  Not used.
730  *
731  * Returns:
732  *	always 0.
733  */
pti_console_setup(struct console * c,char * opts)734 static int pti_console_setup(struct console *c, char *opts)
735 {
736 	pti_console_channel = 0;
737 	pti_control_channel = 0;
738 	return 0;
739 }
740 
741 /*
742  * pti_console struct, used to capture OS printk()'s and shift
743  * out to the PTI device for debugging.  This cannot be
744  * enabled upon boot because of the possibility of eating
745  * any serial console printk's (race condition discovered).
746  * The console should be enabled upon when the tty port is
747  * used for the first time.  Since the primary purpose for
748  * the tty port is to hook up syslog to it, the tty port
749  * will be open for a really long time.
750  */
751 static struct console pti_console = {
752 	.name		= TTYNAME,
753 	.write		= pti_console_write,
754 	.device		= pti_console_device,
755 	.setup		= pti_console_setup,
756 	.flags		= CON_PRINTBUFFER,
757 	.index		= 0,
758 };
759 
760 /**
761  * pti_port_activate()- Used to start/initialize any items upon
762  * first opening of tty_port().
763  *
764  * @port- The tty port number of the PTI device.
765  * @tty-  The tty struct associated with this device.
766  *
767  * Returns:
768  *	always returns 0
769  *
770  * Notes: The primary purpose of the PTI tty port 0 is to hook
771  * the syslog daemon to it; thus this port will be open for a
772  * very long time.
773  */
pti_port_activate(struct tty_port * port,struct tty_struct * tty)774 static int pti_port_activate(struct tty_port *port, struct tty_struct *tty)
775 {
776 	if (port->tty->index == PTITTY_MINOR_START)
777 		console_start(&pti_console);
778 	return 0;
779 }
780 
781 /**
782  * pti_port_shutdown()- Used to stop/shutdown any items upon the
783  * last tty port close.
784  *
785  * @port- The tty port number of the PTI device.
786  *
787  * Notes: The primary purpose of the PTI tty port 0 is to hook
788  * the syslog daemon to it; thus this port will be open for a
789  * very long time.
790  */
pti_port_shutdown(struct tty_port * port)791 static void pti_port_shutdown(struct tty_port *port)
792 {
793 	if (port->tty->index == PTITTY_MINOR_START)
794 		console_stop(&pti_console);
795 }
796 
797 static const struct tty_port_operations tty_port_ops = {
798 	.activate = pti_port_activate,
799 	.shutdown = pti_port_shutdown,
800 };
801 
802 /*
803  * Note the _probe() call sets everything up and ties the char and tty
804  * to successfully detecting the PTI device on the pci bus.
805  */
806 
807 /**
808  * pti_pci_probe()- Used to detect pti on the pci bus and set
809  *		    things up in the driver.
810  *
811  * @pdev- pci_dev struct values for pti.
812  * @ent-  pci_device_id struct for pti driver.
813  *
814  * Returns:
815  *	0 for success
816  *	otherwise, error
817  */
pti_pci_probe(struct pci_dev * pdev,const struct pci_device_id * ent)818 static int __devinit pti_pci_probe(struct pci_dev *pdev,
819 		const struct pci_device_id *ent)
820 {
821 	int retval = -EINVAL;
822 	int pci_bar = 1;
823 
824 	dev_dbg(&pdev->dev, "%s %s(%d): PTI PCI ID %04x:%04x\n", __FILE__,
825 			__func__, __LINE__, pdev->vendor, pdev->device);
826 
827 	retval = misc_register(&pti_char_driver);
828 	if (retval) {
829 		pr_err("%s(%d): CHAR registration failed of pti driver\n",
830 			__func__, __LINE__);
831 		pr_err("%s(%d): Error value returned: %d\n",
832 			__func__, __LINE__, retval);
833 		return retval;
834 	}
835 
836 	retval = pci_enable_device(pdev);
837 	if (retval != 0) {
838 		dev_err(&pdev->dev,
839 			"%s: pci_enable_device() returned error %d\n",
840 			__func__, retval);
841 		return retval;
842 	}
843 
844 	drv_data = kzalloc(sizeof(*drv_data), GFP_KERNEL);
845 
846 	if (drv_data == NULL) {
847 		retval = -ENOMEM;
848 		dev_err(&pdev->dev,
849 			"%s(%d): kmalloc() returned NULL memory.\n",
850 			__func__, __LINE__);
851 		return retval;
852 	}
853 	drv_data->pti_addr = pci_resource_start(pdev, pci_bar);
854 
855 	retval = pci_request_region(pdev, pci_bar, dev_name(&pdev->dev));
856 	if (retval != 0) {
857 		dev_err(&pdev->dev,
858 			"%s(%d): pci_request_region() returned error %d\n",
859 			__func__, __LINE__, retval);
860 		kfree(drv_data);
861 		return retval;
862 	}
863 	drv_data->aperture_base = drv_data->pti_addr+APERTURE_14;
864 	drv_data->pti_ioaddr =
865 		ioremap_nocache((u32)drv_data->aperture_base,
866 		APERTURE_LEN);
867 	if (!drv_data->pti_ioaddr) {
868 		pci_release_region(pdev, pci_bar);
869 		retval = -ENOMEM;
870 		kfree(drv_data);
871 		return retval;
872 	}
873 
874 	pci_set_drvdata(pdev, drv_data);
875 
876 	tty_port_init(&drv_data->port);
877 	drv_data->port.ops = &tty_port_ops;
878 
879 	tty_register_device(pti_tty_driver, 0, &pdev->dev);
880 	tty_register_device(pti_tty_driver, 1, &pdev->dev);
881 
882 	register_console(&pti_console);
883 
884 	return retval;
885 }
886 
887 static struct pci_driver pti_pci_driver = {
888 	.name		= PCINAME,
889 	.id_table	= pci_ids,
890 	.probe		= pti_pci_probe,
891 	.remove		= pti_pci_remove,
892 };
893 
894 /**
895  *
896  * pti_init()- Overall entry/init call to the pti driver.
897  *             It starts the registration process with the kernel.
898  *
899  * Returns:
900  *	int __init, 0 for success
901  *	otherwise value is an error
902  *
903  */
pti_init(void)904 static int __init pti_init(void)
905 {
906 	int retval = -EINVAL;
907 
908 	/* First register module as tty device */
909 
910 	pti_tty_driver = alloc_tty_driver(PTITTY_MINOR_NUM);
911 	if (pti_tty_driver == NULL) {
912 		pr_err("%s(%d): Memory allocation failed for ptiTTY driver\n",
913 			__func__, __LINE__);
914 		return -ENOMEM;
915 	}
916 
917 	pti_tty_driver->driver_name		= DRIVERNAME;
918 	pti_tty_driver->name			= TTYNAME;
919 	pti_tty_driver->major			= 0;
920 	pti_tty_driver->minor_start		= PTITTY_MINOR_START;
921 	pti_tty_driver->type			= TTY_DRIVER_TYPE_SYSTEM;
922 	pti_tty_driver->subtype			= SYSTEM_TYPE_SYSCONS;
923 	pti_tty_driver->flags			= TTY_DRIVER_REAL_RAW |
924 						  TTY_DRIVER_DYNAMIC_DEV;
925 	pti_tty_driver->init_termios		= tty_std_termios;
926 
927 	tty_set_operations(pti_tty_driver, &pti_tty_driver_ops);
928 
929 	retval = tty_register_driver(pti_tty_driver);
930 	if (retval) {
931 		pr_err("%s(%d): TTY registration failed of pti driver\n",
932 			__func__, __LINE__);
933 		pr_err("%s(%d): Error value returned: %d\n",
934 			__func__, __LINE__, retval);
935 
936 		pti_tty_driver = NULL;
937 		return retval;
938 	}
939 
940 	retval = pci_register_driver(&pti_pci_driver);
941 
942 	if (retval) {
943 		pr_err("%s(%d): PCI registration failed of pti driver\n",
944 			__func__, __LINE__);
945 		pr_err("%s(%d): Error value returned: %d\n",
946 			__func__, __LINE__, retval);
947 
948 		tty_unregister_driver(pti_tty_driver);
949 		pr_err("%s(%d): Unregistering TTY part of pti driver\n",
950 			__func__, __LINE__);
951 		pti_tty_driver = NULL;
952 		return retval;
953 	}
954 
955 	return retval;
956 }
957 
958 /**
959  * pti_exit()- Unregisters this module as a tty and pci driver.
960  */
pti_exit(void)961 static void __exit pti_exit(void)
962 {
963 	int retval;
964 
965 	tty_unregister_device(pti_tty_driver, 0);
966 	tty_unregister_device(pti_tty_driver, 1);
967 
968 	retval = tty_unregister_driver(pti_tty_driver);
969 	if (retval) {
970 		pr_err("%s(%d): TTY unregistration failed of pti driver\n",
971 			__func__, __LINE__);
972 		pr_err("%s(%d): Error value returned: %d\n",
973 			__func__, __LINE__, retval);
974 	}
975 
976 	pci_unregister_driver(&pti_pci_driver);
977 
978 	retval = misc_deregister(&pti_char_driver);
979 	if (retval) {
980 		pr_err("%s(%d): CHAR unregistration failed of pti driver\n",
981 			__func__, __LINE__);
982 		pr_err("%s(%d): Error value returned: %d\n",
983 			__func__, __LINE__, retval);
984 	}
985 
986 	unregister_console(&pti_console);
987 	return;
988 }
989 
990 module_init(pti_init);
991 module_exit(pti_exit);
992 
993 MODULE_LICENSE("GPL");
994 MODULE_AUTHOR("Ken Mills, Jay Freyensee");
995 MODULE_DESCRIPTION("PTI Driver");
996 
997