KVM: Fix unlikely kvm_create vs decache_vcpus_on_cpu race
[linux-2.6] / drivers / char / vme_scc.c
1 /*
2  * drivers/char/vme_scc.c: MVME147, MVME162, BVME6000 SCC serial ports
3  * implementation.
4  * Copyright 1999 Richard Hirst <richard@sleepie.demon.co.uk>
5  *
6  * Based on atari_SCC.c which was
7  *   Copyright 1994-95 Roman Hodek <Roman.Hodek@informatik.uni-erlangen.de>
8  *   Partially based on PC-Linux serial.c by Linus Torvalds and Theodore Ts'o
9  *
10  * This file is subject to the terms and conditions of the GNU General Public
11  * License.  See the file COPYING in the main directory of this archive
12  * for more details.
13  *
14  */
15
16 #include <linux/module.h>
17 #include <linux/kdev_t.h>
18 #include <asm/io.h>
19 #include <linux/kernel.h>
20 #include <linux/ioport.h>
21 #include <linux/interrupt.h>
22 #include <linux/errno.h>
23 #include <linux/tty.h>
24 #include <linux/tty_flip.h>
25 #include <linux/mm.h>
26 #include <linux/serial.h>
27 #include <linux/fcntl.h>
28 #include <linux/major.h>
29 #include <linux/delay.h>
30 #include <linux/slab.h>
31 #include <linux/miscdevice.h>
32 #include <linux/console.h>
33 #include <linux/init.h>
34 #include <asm/setup.h>
35 #include <asm/bootinfo.h>
36
37 #ifdef CONFIG_MVME147_SCC
38 #include <asm/mvme147hw.h>
39 #endif
40 #ifdef CONFIG_MVME162_SCC
41 #include <asm/mvme16xhw.h>
42 #endif
43 #ifdef CONFIG_BVME6000_SCC
44 #include <asm/bvme6000hw.h>
45 #endif
46
47 #include <linux/generic_serial.h>
48 #include "scc.h"
49
50
51 #define CHANNEL_A       0
52 #define CHANNEL_B       1
53
54 #define SCC_MINOR_BASE  64
55
56 /* Shadows for all SCC write registers */
57 static unsigned char scc_shadow[2][16];
58
59 /* Location to access for SCC register access delay */
60 static volatile unsigned char *scc_del = NULL;
61
62 /* To keep track of STATUS_REG state for detection of Ext/Status int source */
63 static unsigned char scc_last_status_reg[2];
64
65 /***************************** Prototypes *****************************/
66
67 /* Function prototypes */
68 static void scc_disable_tx_interrupts(void * ptr);
69 static void scc_enable_tx_interrupts(void * ptr);
70 static void scc_disable_rx_interrupts(void * ptr);
71 static void scc_enable_rx_interrupts(void * ptr);
72 static int  scc_get_CD(void * ptr);
73 static void scc_shutdown_port(void * ptr);
74 static int scc_set_real_termios(void  *ptr);
75 static void scc_hungup(void  *ptr);
76 static void scc_close(void  *ptr);
77 static int scc_chars_in_buffer(void * ptr);
78 static int scc_open(struct tty_struct * tty, struct file * filp);
79 static int scc_ioctl(struct tty_struct * tty, struct file * filp,
80                      unsigned int cmd, unsigned long arg);
81 static void scc_throttle(struct tty_struct *tty);
82 static void scc_unthrottle(struct tty_struct *tty);
83 static irqreturn_t scc_tx_int(int irq, void *data);
84 static irqreturn_t scc_rx_int(int irq, void *data);
85 static irqreturn_t scc_stat_int(int irq, void *data);
86 static irqreturn_t scc_spcond_int(int irq, void *data);
87 static void scc_setsignals(struct scc_port *port, int dtr, int rts);
88 static void scc_break_ctl(struct tty_struct *tty, int break_state);
89
90 static struct tty_driver *scc_driver;
91
92 struct scc_port scc_ports[2];
93
94 int scc_initialized = 0;
95
96 /*---------------------------------------------------------------------------
97  * Interface from generic_serial.c back here
98  *--------------------------------------------------------------------------*/
99
100 static struct real_driver scc_real_driver = {
101         scc_disable_tx_interrupts,
102         scc_enable_tx_interrupts,
103         scc_disable_rx_interrupts,
104         scc_enable_rx_interrupts,
105         scc_get_CD,
106         scc_shutdown_port,
107         scc_set_real_termios,
108         scc_chars_in_buffer,
109         scc_close,
110         scc_hungup,
111         NULL
112 };
113
114
115 static const struct tty_operations scc_ops = {
116         .open   = scc_open,
117         .close = gs_close,
118         .write = gs_write,
119         .put_char = gs_put_char,
120         .flush_chars = gs_flush_chars,
121         .write_room = gs_write_room,
122         .chars_in_buffer = gs_chars_in_buffer,
123         .flush_buffer = gs_flush_buffer,
124         .ioctl = scc_ioctl,
125         .throttle = scc_throttle,
126         .unthrottle = scc_unthrottle,
127         .set_termios = gs_set_termios,
128         .stop = gs_stop,
129         .start = gs_start,
130         .hangup = gs_hangup,
131         .break_ctl = scc_break_ctl,
132 };
133
134 /*----------------------------------------------------------------------------
135  * vme_scc_init() and support functions
136  *---------------------------------------------------------------------------*/
137
138 static int scc_init_drivers(void)
139 {
140         int error;
141
142         scc_driver = alloc_tty_driver(2);
143         if (!scc_driver)
144                 return -ENOMEM;
145         scc_driver->owner = THIS_MODULE;
146         scc_driver->driver_name = "scc";
147         scc_driver->name = "ttyS";
148         scc_driver->major = TTY_MAJOR;
149         scc_driver->minor_start = SCC_MINOR_BASE;
150         scc_driver->type = TTY_DRIVER_TYPE_SERIAL;
151         scc_driver->subtype = SERIAL_TYPE_NORMAL;
152         scc_driver->init_termios = tty_std_termios;
153         scc_driver->init_termios.c_cflag =
154           B9600 | CS8 | CREAD | HUPCL | CLOCAL;
155         scc_driver->init_termios.c_ispeed = 9600;
156         scc_driver->init_termios.c_ospeed = 9600;
157         scc_driver->flags = TTY_DRIVER_REAL_RAW;
158         tty_set_operations(scc_driver, &scc_ops);
159
160         if ((error = tty_register_driver(scc_driver))) {
161                 printk(KERN_ERR "scc: Couldn't register scc driver, error = %d\n",
162                        error);
163                 put_tty_driver(scc_driver);
164                 return 1;
165         }
166
167         return 0;
168 }
169
170
171 /* ports[] array is indexed by line no (i.e. [0] for ttyS0, [1] for ttyS1).
172  */
173
174 static void scc_init_portstructs(void)
175 {
176         struct scc_port *port;
177         int i;
178
179         for (i = 0; i < 2; i++) {
180                 port = scc_ports + i;
181                 port->gs.magic = SCC_MAGIC;
182                 port->gs.close_delay = HZ/2;
183                 port->gs.closing_wait = 30 * HZ;
184                 port->gs.rd = &scc_real_driver;
185 #ifdef NEW_WRITE_LOCKING
186                 port->gs.port_write_mutex = MUTEX;
187 #endif
188                 init_waitqueue_head(&port->gs.open_wait);
189                 init_waitqueue_head(&port->gs.close_wait);
190         }
191 }
192
193
194 #ifdef CONFIG_MVME147_SCC
195 static int mvme147_scc_init(void)
196 {
197         struct scc_port *port;
198
199         printk(KERN_INFO "SCC: MVME147 Serial Driver\n");
200         /* Init channel A */
201         port = &scc_ports[0];
202         port->channel = CHANNEL_A;
203         port->ctrlp = (volatile unsigned char *)M147_SCC_A_ADDR;
204         port->datap = port->ctrlp + 1;
205         port->port_a = &scc_ports[0];
206         port->port_b = &scc_ports[1];
207         request_irq(MVME147_IRQ_SCCA_TX, scc_tx_int, IRQF_DISABLED,
208                             "SCC-A TX", port);
209         request_irq(MVME147_IRQ_SCCA_STAT, scc_stat_int, IRQF_DISABLED,
210                             "SCC-A status", port);
211         request_irq(MVME147_IRQ_SCCA_RX, scc_rx_int, IRQF_DISABLED,
212                             "SCC-A RX", port);
213         request_irq(MVME147_IRQ_SCCA_SPCOND, scc_spcond_int, IRQF_DISABLED,
214                             "SCC-A special cond", port);
215         {
216                 SCC_ACCESS_INIT(port);
217
218                 /* disable interrupts for this channel */
219                 SCCwrite(INT_AND_DMA_REG, 0);
220                 /* Set the interrupt vector */
221                 SCCwrite(INT_VECTOR_REG, MVME147_IRQ_SCC_BASE);
222                 /* Interrupt parameters: vector includes status, status low */
223                 SCCwrite(MASTER_INT_CTRL, MIC_VEC_INCL_STAT);
224                 SCCmod(MASTER_INT_CTRL, 0xff, MIC_MASTER_INT_ENAB);
225         }
226
227         /* Init channel B */
228         port = &scc_ports[1];
229         port->channel = CHANNEL_B;
230         port->ctrlp = (volatile unsigned char *)M147_SCC_B_ADDR;
231         port->datap = port->ctrlp + 1;
232         port->port_a = &scc_ports[0];
233         port->port_b = &scc_ports[1];
234         request_irq(MVME147_IRQ_SCCB_TX, scc_tx_int, IRQF_DISABLED,
235                             "SCC-B TX", port);
236         request_irq(MVME147_IRQ_SCCB_STAT, scc_stat_int, IRQF_DISABLED,
237                             "SCC-B status", port);
238         request_irq(MVME147_IRQ_SCCB_RX, scc_rx_int, IRQF_DISABLED,
239                             "SCC-B RX", port);
240         request_irq(MVME147_IRQ_SCCB_SPCOND, scc_spcond_int, IRQF_DISABLED,
241                             "SCC-B special cond", port);
242         {
243                 SCC_ACCESS_INIT(port);
244
245                 /* disable interrupts for this channel */
246                 SCCwrite(INT_AND_DMA_REG, 0);
247         }
248
249         /* Ensure interrupts are enabled in the PCC chip */
250         m147_pcc->serial_cntrl=PCC_LEVEL_SERIAL|PCC_INT_ENAB;
251
252         /* Initialise the tty driver structures and register */
253         scc_init_portstructs();
254         scc_init_drivers();
255
256         return 0;
257 }
258 #endif
259
260
261 #ifdef CONFIG_MVME162_SCC
262 static int mvme162_scc_init(void)
263 {
264         struct scc_port *port;
265
266         if (!(mvme16x_config & MVME16x_CONFIG_GOT_SCCA))
267                 return (-ENODEV);
268
269         printk(KERN_INFO "SCC: MVME162 Serial Driver\n");
270         /* Init channel A */
271         port = &scc_ports[0];
272         port->channel = CHANNEL_A;
273         port->ctrlp = (volatile unsigned char *)MVME_SCC_A_ADDR;
274         port->datap = port->ctrlp + 2;
275         port->port_a = &scc_ports[0];
276         port->port_b = &scc_ports[1];
277         request_irq(MVME162_IRQ_SCCA_TX, scc_tx_int, IRQF_DISABLED,
278                             "SCC-A TX", port);
279         request_irq(MVME162_IRQ_SCCA_STAT, scc_stat_int, IRQF_DISABLED,
280                             "SCC-A status", port);
281         request_irq(MVME162_IRQ_SCCA_RX, scc_rx_int, IRQF_DISABLED,
282                             "SCC-A RX", port);
283         request_irq(MVME162_IRQ_SCCA_SPCOND, scc_spcond_int, IRQF_DISABLED,
284                             "SCC-A special cond", port);
285         {
286                 SCC_ACCESS_INIT(port);
287
288                 /* disable interrupts for this channel */
289                 SCCwrite(INT_AND_DMA_REG, 0);
290                 /* Set the interrupt vector */
291                 SCCwrite(INT_VECTOR_REG, MVME162_IRQ_SCC_BASE);
292                 /* Interrupt parameters: vector includes status, status low */
293                 SCCwrite(MASTER_INT_CTRL, MIC_VEC_INCL_STAT);
294                 SCCmod(MASTER_INT_CTRL, 0xff, MIC_MASTER_INT_ENAB);
295         }
296
297         /* Init channel B */
298         port = &scc_ports[1];
299         port->channel = CHANNEL_B;
300         port->ctrlp = (volatile unsigned char *)MVME_SCC_B_ADDR;
301         port->datap = port->ctrlp + 2;
302         port->port_a = &scc_ports[0];
303         port->port_b = &scc_ports[1];
304         request_irq(MVME162_IRQ_SCCB_TX, scc_tx_int, IRQF_DISABLED,
305                             "SCC-B TX", port);
306         request_irq(MVME162_IRQ_SCCB_STAT, scc_stat_int, IRQF_DISABLED,
307                             "SCC-B status", port);
308         request_irq(MVME162_IRQ_SCCB_RX, scc_rx_int, IRQF_DISABLED,
309                             "SCC-B RX", port);
310         request_irq(MVME162_IRQ_SCCB_SPCOND, scc_spcond_int, IRQF_DISABLED,
311                             "SCC-B special cond", port);
312
313         {
314                 SCC_ACCESS_INIT(port);  /* Either channel will do */
315
316                 /* disable interrupts for this channel */
317                 SCCwrite(INT_AND_DMA_REG, 0);
318         }
319
320         /* Ensure interrupts are enabled in the MC2 chip */
321         *(volatile char *)0xfff4201d = 0x14;
322
323         /* Initialise the tty driver structures and register */
324         scc_init_portstructs();
325         scc_init_drivers();
326
327         return 0;
328 }
329 #endif
330
331
332 #ifdef CONFIG_BVME6000_SCC
333 static int bvme6000_scc_init(void)
334 {
335         struct scc_port *port;
336
337         printk(KERN_INFO "SCC: BVME6000 Serial Driver\n");
338         /* Init channel A */
339         port = &scc_ports[0];
340         port->channel = CHANNEL_A;
341         port->ctrlp = (volatile unsigned char *)BVME_SCC_A_ADDR;
342         port->datap = port->ctrlp + 4;
343         port->port_a = &scc_ports[0];
344         port->port_b = &scc_ports[1];
345         request_irq(BVME_IRQ_SCCA_TX, scc_tx_int, IRQF_DISABLED,
346                             "SCC-A TX", port);
347         request_irq(BVME_IRQ_SCCA_STAT, scc_stat_int, IRQF_DISABLED,
348                             "SCC-A status", port);
349         request_irq(BVME_IRQ_SCCA_RX, scc_rx_int, IRQF_DISABLED,
350                             "SCC-A RX", port);
351         request_irq(BVME_IRQ_SCCA_SPCOND, scc_spcond_int, IRQF_DISABLED,
352                             "SCC-A special cond", port);
353         {
354                 SCC_ACCESS_INIT(port);
355
356                 /* disable interrupts for this channel */
357                 SCCwrite(INT_AND_DMA_REG, 0);
358                 /* Set the interrupt vector */
359                 SCCwrite(INT_VECTOR_REG, BVME_IRQ_SCC_BASE);
360                 /* Interrupt parameters: vector includes status, status low */
361                 SCCwrite(MASTER_INT_CTRL, MIC_VEC_INCL_STAT);
362                 SCCmod(MASTER_INT_CTRL, 0xff, MIC_MASTER_INT_ENAB);
363         }
364
365         /* Init channel B */
366         port = &scc_ports[1];
367         port->channel = CHANNEL_B;
368         port->ctrlp = (volatile unsigned char *)BVME_SCC_B_ADDR;
369         port->datap = port->ctrlp + 4;
370         port->port_a = &scc_ports[0];
371         port->port_b = &scc_ports[1];
372         request_irq(BVME_IRQ_SCCB_TX, scc_tx_int, IRQF_DISABLED,
373                             "SCC-B TX", port);
374         request_irq(BVME_IRQ_SCCB_STAT, scc_stat_int, IRQF_DISABLED,
375                             "SCC-B status", port);
376         request_irq(BVME_IRQ_SCCB_RX, scc_rx_int, IRQF_DISABLED,
377                             "SCC-B RX", port);
378         request_irq(BVME_IRQ_SCCB_SPCOND, scc_spcond_int, IRQF_DISABLED,
379                             "SCC-B special cond", port);
380
381         {
382                 SCC_ACCESS_INIT(port);  /* Either channel will do */
383
384                 /* disable interrupts for this channel */
385                 SCCwrite(INT_AND_DMA_REG, 0);
386         }
387
388         /* Initialise the tty driver structures and register */
389         scc_init_portstructs();
390         scc_init_drivers();
391
392         return 0;
393 }
394 #endif
395
396
397 static int vme_scc_init(void)
398 {
399         int res = -ENODEV;
400
401 #ifdef CONFIG_MVME147_SCC
402         if (MACH_IS_MVME147)
403                 res = mvme147_scc_init();
404 #endif
405 #ifdef CONFIG_MVME162_SCC
406         if (MACH_IS_MVME16x)
407                 res = mvme162_scc_init();
408 #endif
409 #ifdef CONFIG_BVME6000_SCC
410         if (MACH_IS_BVME6000)
411                 res = bvme6000_scc_init();
412 #endif
413         return res;
414 }
415
416 module_init(vme_scc_init);
417
418
419 /*---------------------------------------------------------------------------
420  * Interrupt handlers
421  *--------------------------------------------------------------------------*/
422
423 static irqreturn_t scc_rx_int(int irq, void *data)
424 {
425         unsigned char   ch;
426         struct scc_port *port = data;
427         struct tty_struct *tty = port->gs.tty;
428         SCC_ACCESS_INIT(port);
429
430         ch = SCCread_NB(RX_DATA_REG);
431         if (!tty) {
432                 printk(KERN_WARNING "scc_rx_int with NULL tty!\n");
433                 SCCwrite_NB(COMMAND_REG, CR_HIGHEST_IUS_RESET);
434                 return IRQ_HANDLED;
435         }
436         tty_insert_flip_char(tty, ch, 0);
437
438         /* Check if another character is already ready; in that case, the
439          * spcond_int() function must be used, because this character may have an
440          * error condition that isn't signalled by the interrupt vector used!
441          */
442         if (SCCread(INT_PENDING_REG) &
443             (port->channel == CHANNEL_A ? IPR_A_RX : IPR_B_RX)) {
444                 scc_spcond_int (irq, data);
445                 return IRQ_HANDLED;
446         }
447
448         SCCwrite_NB(COMMAND_REG, CR_HIGHEST_IUS_RESET);
449
450         tty_flip_buffer_push(tty);
451         return IRQ_HANDLED;
452 }
453
454
455 static irqreturn_t scc_spcond_int(int irq, void *data)
456 {
457         struct scc_port *port = data;
458         struct tty_struct *tty = port->gs.tty;
459         unsigned char   stat, ch, err;
460         int             int_pending_mask = port->channel == CHANNEL_A ?
461                                            IPR_A_RX : IPR_B_RX;
462         SCC_ACCESS_INIT(port);
463         
464         if (!tty) {
465                 printk(KERN_WARNING "scc_spcond_int with NULL tty!\n");
466                 SCCwrite(COMMAND_REG, CR_ERROR_RESET);
467                 SCCwrite_NB(COMMAND_REG, CR_HIGHEST_IUS_RESET);
468                 return IRQ_HANDLED;
469         }
470         do {
471                 stat = SCCread(SPCOND_STATUS_REG);
472                 ch = SCCread_NB(RX_DATA_REG);
473
474                 if (stat & SCSR_RX_OVERRUN)
475                         err = TTY_OVERRUN;
476                 else if (stat & SCSR_PARITY_ERR)
477                         err = TTY_PARITY;
478                 else if (stat & SCSR_CRC_FRAME_ERR)
479                         err = TTY_FRAME;
480                 else
481                         err = 0;
482
483                 tty_insert_flip_char(tty, ch, err);
484
485                 /* ++TeSche: *All* errors have to be cleared manually,
486                  * else the condition persists for the next chars
487                  */
488                 if (err)
489                   SCCwrite(COMMAND_REG, CR_ERROR_RESET);
490
491         } while(SCCread(INT_PENDING_REG) & int_pending_mask);
492
493         SCCwrite_NB(COMMAND_REG, CR_HIGHEST_IUS_RESET);
494
495         tty_flip_buffer_push(tty);
496         return IRQ_HANDLED;
497 }
498
499
500 static irqreturn_t scc_tx_int(int irq, void *data)
501 {
502         struct scc_port *port = data;
503         SCC_ACCESS_INIT(port);
504
505         if (!port->gs.tty) {
506                 printk(KERN_WARNING "scc_tx_int with NULL tty!\n");
507                 SCCmod (INT_AND_DMA_REG, ~IDR_TX_INT_ENAB, 0);
508                 SCCwrite(COMMAND_REG, CR_TX_PENDING_RESET);
509                 SCCwrite_NB(COMMAND_REG, CR_HIGHEST_IUS_RESET);
510                 return IRQ_HANDLED;
511         }
512         while ((SCCread_NB(STATUS_REG) & SR_TX_BUF_EMPTY)) {
513                 if (port->x_char) {
514                         SCCwrite(TX_DATA_REG, port->x_char);
515                         port->x_char = 0;
516                 }
517                 else if ((port->gs.xmit_cnt <= 0) || port->gs.tty->stopped ||
518                                 port->gs.tty->hw_stopped)
519                         break;
520                 else {
521                         SCCwrite(TX_DATA_REG, port->gs.xmit_buf[port->gs.xmit_tail++]);
522                         port->gs.xmit_tail = port->gs.xmit_tail & (SERIAL_XMIT_SIZE-1);
523                         if (--port->gs.xmit_cnt <= 0)
524                                 break;
525                 }
526         }
527         if ((port->gs.xmit_cnt <= 0) || port->gs.tty->stopped ||
528                         port->gs.tty->hw_stopped) {
529                 /* disable tx interrupts */
530                 SCCmod (INT_AND_DMA_REG, ~IDR_TX_INT_ENAB, 0);
531                 SCCwrite(COMMAND_REG, CR_TX_PENDING_RESET);   /* disable tx_int on next tx underrun? */
532                 port->gs.flags &= ~GS_TX_INTEN;
533         }
534         if (port->gs.tty && port->gs.xmit_cnt <= port->gs.wakeup_chars)
535                 tty_wakeup(port->gs.tty);
536
537         SCCwrite_NB(COMMAND_REG, CR_HIGHEST_IUS_RESET);
538         return IRQ_HANDLED;
539 }
540
541
542 static irqreturn_t scc_stat_int(int irq, void *data)
543 {
544         struct scc_port *port = data;
545         unsigned channel = port->channel;
546         unsigned char   last_sr, sr, changed;
547         SCC_ACCESS_INIT(port);
548
549         last_sr = scc_last_status_reg[channel];
550         sr = scc_last_status_reg[channel] = SCCread_NB(STATUS_REG);
551         changed = last_sr ^ sr;
552
553         if (changed & SR_DCD) {
554                 port->c_dcd = !!(sr & SR_DCD);
555                 if (!(port->gs.flags & ASYNC_CHECK_CD))
556                         ;       /* Don't report DCD changes */
557                 else if (port->c_dcd) {
558                         wake_up_interruptible(&port->gs.open_wait);
559                 }
560                 else {
561                         if (port->gs.tty)
562                                 tty_hangup (port->gs.tty);
563                 }
564         }
565         SCCwrite(COMMAND_REG, CR_EXTSTAT_RESET);
566         SCCwrite_NB(COMMAND_REG, CR_HIGHEST_IUS_RESET);
567         return IRQ_HANDLED;
568 }
569
570
571 /*---------------------------------------------------------------------------
572  * generic_serial.c callback funtions
573  *--------------------------------------------------------------------------*/
574
575 static void scc_disable_tx_interrupts(void *ptr)
576 {
577         struct scc_port *port = ptr;
578         unsigned long   flags;
579         SCC_ACCESS_INIT(port);
580
581         local_irq_save(flags);
582         SCCmod(INT_AND_DMA_REG, ~IDR_TX_INT_ENAB, 0);
583         port->gs.flags &= ~GS_TX_INTEN;
584         local_irq_restore(flags);
585 }
586
587
588 static void scc_enable_tx_interrupts(void *ptr)
589 {
590         struct scc_port *port = ptr;
591         unsigned long   flags;
592         SCC_ACCESS_INIT(port);
593
594         local_irq_save(flags);
595         SCCmod(INT_AND_DMA_REG, 0xff, IDR_TX_INT_ENAB);
596         /* restart the transmitter */
597         scc_tx_int (0, port);
598         local_irq_restore(flags);
599 }
600
601
602 static void scc_disable_rx_interrupts(void *ptr)
603 {
604         struct scc_port *port = ptr;
605         unsigned long   flags;
606         SCC_ACCESS_INIT(port);
607
608         local_irq_save(flags);
609         SCCmod(INT_AND_DMA_REG,
610             ~(IDR_RX_INT_MASK|IDR_PARERR_AS_SPCOND|IDR_EXTSTAT_INT_ENAB), 0);
611         local_irq_restore(flags);
612 }
613
614
615 static void scc_enable_rx_interrupts(void *ptr)
616 {
617         struct scc_port *port = ptr;
618         unsigned long   flags;
619         SCC_ACCESS_INIT(port);
620
621         local_irq_save(flags);
622         SCCmod(INT_AND_DMA_REG, 0xff,
623                 IDR_EXTSTAT_INT_ENAB|IDR_PARERR_AS_SPCOND|IDR_RX_INT_ALL);
624         local_irq_restore(flags);
625 }
626
627
628 static int scc_get_CD(void *ptr)
629 {
630         struct scc_port *port = ptr;
631         unsigned channel = port->channel;
632
633         return !!(scc_last_status_reg[channel] & SR_DCD);
634 }
635
636
637 static void scc_shutdown_port(void *ptr)
638 {
639         struct scc_port *port = ptr;
640
641         port->gs.flags &= ~ GS_ACTIVE;
642         if (port->gs.tty && port->gs.tty->termios->c_cflag & HUPCL) {
643                 scc_setsignals (port, 0, 0);
644         }
645 }
646
647
648 static int scc_set_real_termios (void *ptr)
649 {
650         /* the SCC has char sizes 5,7,6,8 in that order! */
651         static int chsize_map[4] = { 0, 2, 1, 3 };
652         unsigned cflag, baud, chsize, channel, brgval = 0;
653         unsigned long flags;
654         struct scc_port *port = ptr;
655         SCC_ACCESS_INIT(port);
656
657         if (!port->gs.tty || !port->gs.tty->termios) return 0;
658
659         channel = port->channel;
660
661         if (channel == CHANNEL_A)
662                 return 0;               /* Settings controlled by boot PROM */
663
664         cflag  = port->gs.tty->termios->c_cflag;
665         baud = port->gs.baud;
666         chsize = (cflag & CSIZE) >> 4;
667
668         if (baud == 0) {
669                 /* speed == 0 -> drop DTR */
670                 local_irq_save(flags);
671                 SCCmod(TX_CTRL_REG, ~TCR_DTR, 0);
672                 local_irq_restore(flags);
673                 return 0;
674         }
675         else if ((MACH_IS_MVME16x && (baud < 50 || baud > 38400)) ||
676                  (MACH_IS_MVME147 && (baud < 50 || baud > 19200)) ||
677                  (MACH_IS_BVME6000 &&(baud < 50 || baud > 76800))) {
678                 printk(KERN_NOTICE "SCC: Bad speed requested, %d\n", baud);
679                 return 0;
680         }
681
682         if (cflag & CLOCAL)
683                 port->gs.flags &= ~ASYNC_CHECK_CD;
684         else
685                 port->gs.flags |= ASYNC_CHECK_CD;
686
687 #ifdef CONFIG_MVME147_SCC
688         if (MACH_IS_MVME147)
689                 brgval = (M147_SCC_PCLK + baud/2) / (16 * 2 * baud) - 2;
690 #endif
691 #ifdef CONFIG_MVME162_SCC
692         if (MACH_IS_MVME16x)
693                 brgval = (MVME_SCC_PCLK + baud/2) / (16 * 2 * baud) - 2;
694 #endif
695 #ifdef CONFIG_BVME6000_SCC
696         if (MACH_IS_BVME6000)
697                 brgval = (BVME_SCC_RTxC + baud/2) / (16 * 2 * baud) - 2;
698 #endif
699         /* Now we have all parameters and can go to set them: */
700         local_irq_save(flags);
701
702         /* receiver's character size and auto-enables */
703         SCCmod(RX_CTRL_REG, ~(RCR_CHSIZE_MASK|RCR_AUTO_ENAB_MODE),
704                         (chsize_map[chsize] << 6) |
705                         ((cflag & CRTSCTS) ? RCR_AUTO_ENAB_MODE : 0));
706         /* parity and stop bits (both, Tx and Rx), clock mode never changes */
707         SCCmod (AUX1_CTRL_REG,
708                 ~(A1CR_PARITY_MASK | A1CR_MODE_MASK),
709                 ((cflag & PARENB
710                   ? (cflag & PARODD ? A1CR_PARITY_ODD : A1CR_PARITY_EVEN)
711                   : A1CR_PARITY_NONE)
712                  | (cflag & CSTOPB ? A1CR_MODE_ASYNC_2 : A1CR_MODE_ASYNC_1)));
713         /* sender's character size, set DTR for valid baud rate */
714         SCCmod(TX_CTRL_REG, ~TCR_CHSIZE_MASK, chsize_map[chsize] << 5 | TCR_DTR);
715         /* clock sources never change */
716         /* disable BRG before changing the value */
717         SCCmod(DPLL_CTRL_REG, ~DCR_BRG_ENAB, 0);
718         /* BRG value */
719         SCCwrite(TIMER_LOW_REG, brgval & 0xff);
720         SCCwrite(TIMER_HIGH_REG, (brgval >> 8) & 0xff);
721         /* BRG enable, and clock source never changes */
722         SCCmod(DPLL_CTRL_REG, 0xff, DCR_BRG_ENAB);
723
724         local_irq_restore(flags);
725
726         return 0;
727 }
728
729
730 static int scc_chars_in_buffer (void *ptr)
731 {
732         struct scc_port *port = ptr;
733         SCC_ACCESS_INIT(port);
734
735         return (SCCread (SPCOND_STATUS_REG) & SCSR_ALL_SENT) ? 0  : 1;
736 }
737
738
739 /* Comment taken from sx.c (2.4.0):
740    I haven't the foggiest why the decrement use count has to happen
741    here. The whole linux serial drivers stuff needs to be redesigned.
742    My guess is that this is a hack to minimize the impact of a bug
743    elsewhere. Thinking about it some more. (try it sometime) Try
744    running minicom on a serial port that is driven by a modularized
745    driver. Have the modem hangup. Then remove the driver module. Then
746    exit minicom.  I expect an "oops".  -- REW */
747
748 static void scc_hungup(void *ptr)
749 {
750         scc_disable_tx_interrupts(ptr);
751         scc_disable_rx_interrupts(ptr);
752 }
753
754
755 static void scc_close(void *ptr)
756 {
757         scc_disable_tx_interrupts(ptr);
758         scc_disable_rx_interrupts(ptr);
759 }
760
761
762 /*---------------------------------------------------------------------------
763  * Internal support functions
764  *--------------------------------------------------------------------------*/
765
766 static void scc_setsignals(struct scc_port *port, int dtr, int rts)
767 {
768         unsigned long flags;
769         unsigned char t;
770         SCC_ACCESS_INIT(port);
771
772         local_irq_save(flags);
773         t = SCCread(TX_CTRL_REG);
774         if (dtr >= 0) t = dtr? (t | TCR_DTR): (t & ~TCR_DTR);
775         if (rts >= 0) t = rts? (t | TCR_RTS): (t & ~TCR_RTS);
776         SCCwrite(TX_CTRL_REG, t);
777         local_irq_restore(flags);
778 }
779
780
781 static void scc_send_xchar(struct tty_struct *tty, char ch)
782 {
783         struct scc_port *port = (struct scc_port *)tty->driver_data;
784
785         port->x_char = ch;
786         if (ch)
787                 scc_enable_tx_interrupts(port);
788 }
789
790
791 /*---------------------------------------------------------------------------
792  * Driver entrypoints referenced from above
793  *--------------------------------------------------------------------------*/
794
795 static int scc_open (struct tty_struct * tty, struct file * filp)
796 {
797         int line = tty->index;
798         int retval;
799         struct scc_port *port = &scc_ports[line];
800         int i, channel = port->channel;
801         unsigned long   flags;
802         SCC_ACCESS_INIT(port);
803 #if defined(CONFIG_MVME162_SCC) || defined(CONFIG_MVME147_SCC)
804         static const struct {
805                 unsigned reg, val;
806         } mvme_init_tab[] = {
807                 /* Values for MVME162 and MVME147 */
808                 /* no parity, 1 stop bit, async, 1:16 */
809                 { AUX1_CTRL_REG, A1CR_PARITY_NONE|A1CR_MODE_ASYNC_1|A1CR_CLKMODE_x16 },
810                 /* parity error is special cond, ints disabled, no DMA */
811                 { INT_AND_DMA_REG, IDR_PARERR_AS_SPCOND | IDR_RX_INT_DISAB },
812                 /* Rx 8 bits/char, no auto enable, Rx off */
813                 { RX_CTRL_REG, RCR_CHSIZE_8 },
814                 /* DTR off, Tx 8 bits/char, RTS off, Tx off */
815                 { TX_CTRL_REG, TCR_CHSIZE_8 },
816                 /* special features off */
817                 { AUX2_CTRL_REG, 0 },
818                 { CLK_CTRL_REG, CCR_RXCLK_BRG | CCR_TXCLK_BRG },
819                 { DPLL_CTRL_REG, DCR_BRG_ENAB | DCR_BRG_USE_PCLK },
820                 /* Start Rx */
821                 { RX_CTRL_REG, RCR_RX_ENAB | RCR_CHSIZE_8 },
822                 /* Start Tx */
823                 { TX_CTRL_REG, TCR_TX_ENAB | TCR_RTS | TCR_DTR | TCR_CHSIZE_8 },
824                 /* Ext/Stat ints: DCD only */
825                 { INT_CTRL_REG, ICR_ENAB_DCD_INT },
826                 /* Reset Ext/Stat ints */
827                 { COMMAND_REG, CR_EXTSTAT_RESET },
828                 /* ...again */
829                 { COMMAND_REG, CR_EXTSTAT_RESET },
830         };
831 #endif
832 #if defined(CONFIG_BVME6000_SCC)
833         static const struct {
834                 unsigned reg, val;
835         } bvme_init_tab[] = {
836                 /* Values for BVME6000 */
837                 /* no parity, 1 stop bit, async, 1:16 */
838                 { AUX1_CTRL_REG, A1CR_PARITY_NONE|A1CR_MODE_ASYNC_1|A1CR_CLKMODE_x16 },
839                 /* parity error is special cond, ints disabled, no DMA */
840                 { INT_AND_DMA_REG, IDR_PARERR_AS_SPCOND | IDR_RX_INT_DISAB },
841                 /* Rx 8 bits/char, no auto enable, Rx off */
842                 { RX_CTRL_REG, RCR_CHSIZE_8 },
843                 /* DTR off, Tx 8 bits/char, RTS off, Tx off */
844                 { TX_CTRL_REG, TCR_CHSIZE_8 },
845                 /* special features off */
846                 { AUX2_CTRL_REG, 0 },
847                 { CLK_CTRL_REG, CCR_RTxC_XTAL | CCR_RXCLK_BRG | CCR_TXCLK_BRG },
848                 { DPLL_CTRL_REG, DCR_BRG_ENAB },
849                 /* Start Rx */
850                 { RX_CTRL_REG, RCR_RX_ENAB | RCR_CHSIZE_8 },
851                 /* Start Tx */
852                 { TX_CTRL_REG, TCR_TX_ENAB | TCR_RTS | TCR_DTR | TCR_CHSIZE_8 },
853                 /* Ext/Stat ints: DCD only */
854                 { INT_CTRL_REG, ICR_ENAB_DCD_INT },
855                 /* Reset Ext/Stat ints */
856                 { COMMAND_REG, CR_EXTSTAT_RESET },
857                 /* ...again */
858                 { COMMAND_REG, CR_EXTSTAT_RESET },
859         };
860 #endif
861         if (!(port->gs.flags & ASYNC_INITIALIZED)) {
862                 local_irq_save(flags);
863 #if defined(CONFIG_MVME147_SCC) || defined(CONFIG_MVME162_SCC)
864                 if (MACH_IS_MVME147 || MACH_IS_MVME16x) {
865                         for (i = 0; i < ARRAY_SIZE(mvme_init_tab); ++i)
866                                 SCCwrite(mvme_init_tab[i].reg, mvme_init_tab[i].val);
867                 }
868 #endif
869 #if defined(CONFIG_BVME6000_SCC)
870                 if (MACH_IS_BVME6000) {
871                         for (i = 0; i < ARRAY_SIZE(bvme_init_tab); ++i)
872                                 SCCwrite(bvme_init_tab[i].reg, bvme_init_tab[i].val);
873                 }
874 #endif
875
876                 /* remember status register for detection of DCD and CTS changes */
877                 scc_last_status_reg[channel] = SCCread(STATUS_REG);
878
879                 port->c_dcd = 0;        /* Prevent initial 1->0 interrupt */
880                 scc_setsignals (port, 1,1);
881                 local_irq_restore(flags);
882         }
883
884         tty->driver_data = port;
885         port->gs.tty = tty;
886         port->gs.count++;
887         retval = gs_init_port(&port->gs);
888         if (retval) {
889                 port->gs.count--;
890                 return retval;
891         }
892         port->gs.flags |= GS_ACTIVE;
893         retval = gs_block_til_ready(port, filp);
894
895         if (retval) {
896                 port->gs.count--;
897                 return retval;
898         }
899
900         port->c_dcd = scc_get_CD (port);
901
902         scc_enable_rx_interrupts(port);
903
904         return 0;
905 }
906
907
908 static void scc_throttle (struct tty_struct * tty)
909 {
910         struct scc_port *port = (struct scc_port *)tty->driver_data;
911         unsigned long   flags;
912         SCC_ACCESS_INIT(port);
913
914         if (tty->termios->c_cflag & CRTSCTS) {
915                 local_irq_save(flags);
916                 SCCmod(TX_CTRL_REG, ~TCR_RTS, 0);
917                 local_irq_restore(flags);
918         }
919         if (I_IXOFF(tty))
920                 scc_send_xchar(tty, STOP_CHAR(tty));
921 }
922
923
924 static void scc_unthrottle (struct tty_struct * tty)
925 {
926         struct scc_port *port = (struct scc_port *)tty->driver_data;
927         unsigned long   flags;
928         SCC_ACCESS_INIT(port);
929
930         if (tty->termios->c_cflag & CRTSCTS) {
931                 local_irq_save(flags);
932                 SCCmod(TX_CTRL_REG, 0xff, TCR_RTS);
933                 local_irq_restore(flags);
934         }
935         if (I_IXOFF(tty))
936                 scc_send_xchar(tty, START_CHAR(tty));
937 }
938
939
940 static int scc_ioctl(struct tty_struct *tty, struct file *file,
941                      unsigned int cmd, unsigned long arg)
942 {
943         return -ENOIOCTLCMD;
944 }
945
946
947 static void scc_break_ctl(struct tty_struct *tty, int break_state)
948 {
949         struct scc_port *port = (struct scc_port *)tty->driver_data;
950         unsigned long   flags;
951         SCC_ACCESS_INIT(port);
952
953         local_irq_save(flags);
954         SCCmod(TX_CTRL_REG, ~TCR_SEND_BREAK, 
955                         break_state ? TCR_SEND_BREAK : 0);
956         local_irq_restore(flags);
957 }
958
959
960 /*---------------------------------------------------------------------------
961  * Serial console stuff...
962  *--------------------------------------------------------------------------*/
963
964 #define scc_delay() do { __asm__ __volatile__ (" nop; nop"); } while (0)
965
966 static void scc_ch_write (char ch)
967 {
968         volatile char *p = NULL;
969         
970 #ifdef CONFIG_MVME147_SCC
971         if (MACH_IS_MVME147)
972                 p = (volatile char *)M147_SCC_A_ADDR;
973 #endif
974 #ifdef CONFIG_MVME162_SCC
975         if (MACH_IS_MVME16x)
976                 p = (volatile char *)MVME_SCC_A_ADDR;
977 #endif
978 #ifdef CONFIG_BVME6000_SCC
979         if (MACH_IS_BVME6000)
980                 p = (volatile char *)BVME_SCC_A_ADDR;
981 #endif
982
983         do {
984                 scc_delay();
985         }
986         while (!(*p & 4));
987         scc_delay();
988         *p = 8;
989         scc_delay();
990         *p = ch;
991 }
992
993 /* The console must be locked when we get here. */
994
995 static void scc_console_write (struct console *co, const char *str, unsigned count)
996 {
997         unsigned long   flags;
998
999         local_irq_save(flags);
1000
1001         while (count--)
1002         {
1003                 if (*str == '\n')
1004                         scc_ch_write ('\r');
1005                 scc_ch_write (*str++);
1006         }
1007         local_irq_restore(flags);
1008 }
1009
1010 static struct tty_driver *scc_console_device(struct console *c, int *index)
1011 {
1012         *index = c->index;
1013         return scc_driver;
1014 }
1015
1016 static struct console sercons = {
1017         .name           = "ttyS",
1018         .write          = scc_console_write,
1019         .device         = scc_console_device,
1020         .flags          = CON_PRINTBUFFER,
1021         .index          = -1,
1022 };
1023
1024
1025 static int __init vme_scc_console_init(void)
1026 {
1027         if (vme_brdtype == VME_TYPE_MVME147 ||
1028                         vme_brdtype == VME_TYPE_MVME162 ||
1029                         vme_brdtype == VME_TYPE_MVME172 ||
1030                         vme_brdtype == VME_TYPE_BVME4000 ||
1031                         vme_brdtype == VME_TYPE_BVME6000)
1032                 register_console(&sercons);
1033         return 0;
1034 }
1035 console_initcall(vme_scc_console_init);