1 // SPDX-License-Identifier: GPL-2.0-only
2 /* drivers/atm/idt77105.c - IDT77105 (PHY) driver */
3
4 /* Written 1999 by Greg Banks, NEC Australia <gnb@linuxfan.com>. Based on suni.c */
5
6
7 #include <linux/module.h>
8 #include <linux/kernel.h>
9 #include <linux/mm.h>
10 #include <linux/errno.h>
11 #include <linux/atmdev.h>
12 #include <linux/sonet.h>
13 #include <linux/delay.h>
14 #include <linux/timer.h>
15 #include <linux/init.h>
16 #include <linux/capability.h>
17 #include <linux/atm_idt77105.h>
18 #include <linux/spinlock.h>
19 #include <linux/slab.h>
20 #include <asm/param.h>
21 #include <linux/uaccess.h>
22
23 #include "idt77105.h"
24
25 #undef GENERAL_DEBUG
26
27 #ifdef GENERAL_DEBUG
28 #define DPRINTK(format,args...) printk(KERN_DEBUG format,##args)
29 #else
30 #define DPRINTK(format,args...)
31 #endif
32
33
34 struct idt77105_priv {
35 struct idt77105_stats stats; /* link diagnostics */
36 struct atm_dev *dev; /* device back-pointer */
37 struct idt77105_priv *next;
38 int loop_mode;
39 unsigned char old_mcr; /* storage of MCR reg while signal lost */
40 };
41
42 static DEFINE_SPINLOCK(idt77105_priv_lock);
43
44 #define PRIV(dev) ((struct idt77105_priv *) dev->phy_data)
45
46 #define PUT(val,reg) dev->ops->phy_put(dev,val,IDT77105_##reg)
47 #define GET(reg) dev->ops->phy_get(dev,IDT77105_##reg)
48
49 static void idt77105_stats_timer_func(struct timer_list *);
50 static void idt77105_restart_timer_func(struct timer_list *);
51
52
53 static DEFINE_TIMER(stats_timer, idt77105_stats_timer_func);
54 static DEFINE_TIMER(restart_timer, idt77105_restart_timer_func);
55 static int start_timer = 1;
56 static struct idt77105_priv *idt77105_all = NULL;
57
58 /*
59 * Retrieve the value of one of the IDT77105's counters.
60 * `counter' is one of the IDT77105_CTRSEL_* constants.
61 */
get_counter(struct atm_dev * dev,int counter)62 static u16 get_counter(struct atm_dev *dev, int counter)
63 {
64 u16 val;
65
66 /* write the counter bit into PHY register 6 */
67 PUT(counter, CTRSEL);
68 /* read the low 8 bits from register 4 */
69 val = GET(CTRLO);
70 /* read the high 8 bits from register 5 */
71 val |= GET(CTRHI)<<8;
72
73 return val;
74 }
75
76 /*
77 * Timer function called every second to gather statistics
78 * from the 77105. This is done because the h/w registers
79 * will overflow if not read at least once per second. The
80 * kernel's stats are much higher precision. Also, having
81 * a separate copy of the stats allows implementation of
82 * an ioctl which gathers the stats *without* zero'ing them.
83 */
idt77105_stats_timer_func(struct timer_list * unused)84 static void idt77105_stats_timer_func(struct timer_list *unused)
85 {
86 struct idt77105_priv *walk;
87 struct atm_dev *dev;
88 struct idt77105_stats *stats;
89
90 DPRINTK("IDT77105 gathering statistics\n");
91 for (walk = idt77105_all; walk; walk = walk->next) {
92 dev = walk->dev;
93
94 stats = &walk->stats;
95 stats->symbol_errors += get_counter(dev, IDT77105_CTRSEL_SEC);
96 stats->tx_cells += get_counter(dev, IDT77105_CTRSEL_TCC);
97 stats->rx_cells += get_counter(dev, IDT77105_CTRSEL_RCC);
98 stats->rx_hec_errors += get_counter(dev, IDT77105_CTRSEL_RHEC);
99 }
100 if (!start_timer) mod_timer(&stats_timer,jiffies+IDT77105_STATS_TIMER_PERIOD);
101 }
102
103
104 /*
105 * A separate timer func which handles restarting PHY chips which
106 * have had the cable re-inserted after being pulled out. This is
107 * done by polling the Good Signal Bit in the Interrupt Status
108 * register every 5 seconds. The other technique (checking Good
109 * Signal Bit in the interrupt handler) cannot be used because PHY
110 * interrupts need to be disabled when the cable is pulled out
111 * to avoid lots of spurious cell error interrupts.
112 */
idt77105_restart_timer_func(struct timer_list * unused)113 static void idt77105_restart_timer_func(struct timer_list *unused)
114 {
115 struct idt77105_priv *walk;
116 struct atm_dev *dev;
117 unsigned char istat;
118
119 DPRINTK("IDT77105 checking for cable re-insertion\n");
120 for (walk = idt77105_all; walk; walk = walk->next) {
121 dev = walk->dev;
122
123 if (dev->signal != ATM_PHY_SIG_LOST)
124 continue;
125
126 istat = GET(ISTAT); /* side effect: clears all interrupt status bits */
127 if (istat & IDT77105_ISTAT_GOODSIG) {
128 /* Found signal again */
129 atm_dev_signal_change(dev, ATM_PHY_SIG_FOUND);
130 printk(KERN_NOTICE "%s(itf %d): signal detected again\n",
131 dev->type,dev->number);
132 /* flush the receive FIFO */
133 PUT( GET(DIAG) | IDT77105_DIAG_RFLUSH, DIAG);
134 /* re-enable interrupts */
135 PUT( walk->old_mcr ,MCR);
136 }
137 }
138 if (!start_timer) mod_timer(&restart_timer,jiffies+IDT77105_RESTART_TIMER_PERIOD);
139 }
140
141
fetch_stats(struct atm_dev * dev,struct idt77105_stats __user * arg,int zero)142 static int fetch_stats(struct atm_dev *dev,struct idt77105_stats __user *arg,int zero)
143 {
144 unsigned long flags;
145 struct idt77105_stats stats;
146
147 spin_lock_irqsave(&idt77105_priv_lock, flags);
148 memcpy(&stats, &PRIV(dev)->stats, sizeof(struct idt77105_stats));
149 if (zero)
150 memset(&PRIV(dev)->stats, 0, sizeof(struct idt77105_stats));
151 spin_unlock_irqrestore(&idt77105_priv_lock, flags);
152 if (arg == NULL)
153 return 0;
154 return copy_to_user(arg, &stats,
155 sizeof(struct idt77105_stats)) ? -EFAULT : 0;
156 }
157
158
set_loopback(struct atm_dev * dev,int mode)159 static int set_loopback(struct atm_dev *dev,int mode)
160 {
161 int diag;
162
163 diag = GET(DIAG) & ~IDT77105_DIAG_LCMASK;
164 switch (mode) {
165 case ATM_LM_NONE:
166 break;
167 case ATM_LM_LOC_ATM:
168 diag |= IDT77105_DIAG_LC_PHY_LOOPBACK;
169 break;
170 case ATM_LM_RMT_ATM:
171 diag |= IDT77105_DIAG_LC_LINE_LOOPBACK;
172 break;
173 default:
174 return -EINVAL;
175 }
176 PUT(diag,DIAG);
177 printk(KERN_NOTICE "%s(%d) Loopback mode is: %s\n", dev->type,
178 dev->number,
179 (mode == ATM_LM_NONE ? "NONE" :
180 (mode == ATM_LM_LOC_ATM ? "DIAG (local)" :
181 (mode == IDT77105_DIAG_LC_LINE_LOOPBACK ? "LOOP (remote)" :
182 "unknown")))
183 );
184 PRIV(dev)->loop_mode = mode;
185 return 0;
186 }
187
188
idt77105_ioctl(struct atm_dev * dev,unsigned int cmd,void __user * arg)189 static int idt77105_ioctl(struct atm_dev *dev,unsigned int cmd,void __user *arg)
190 {
191 printk(KERN_NOTICE "%s(%d) idt77105_ioctl() called\n",dev->type,dev->number);
192 switch (cmd) {
193 case IDT77105_GETSTATZ:
194 if (!capable(CAP_NET_ADMIN)) return -EPERM;
195 fallthrough;
196 case IDT77105_GETSTAT:
197 return fetch_stats(dev, arg, cmd == IDT77105_GETSTATZ);
198 case ATM_SETLOOP:
199 return set_loopback(dev,(int)(unsigned long) arg);
200 case ATM_GETLOOP:
201 return put_user(PRIV(dev)->loop_mode,(int __user *)arg) ?
202 -EFAULT : 0;
203 case ATM_QUERYLOOP:
204 return put_user(ATM_LM_LOC_ATM | ATM_LM_RMT_ATM,
205 (int __user *) arg) ? -EFAULT : 0;
206 default:
207 return -ENOIOCTLCMD;
208 }
209 }
210
211
212
idt77105_int(struct atm_dev * dev)213 static void idt77105_int(struct atm_dev *dev)
214 {
215 unsigned char istat;
216
217 istat = GET(ISTAT); /* side effect: clears all interrupt status bits */
218
219 DPRINTK("IDT77105 generated an interrupt, istat=%02x\n", (unsigned)istat);
220
221 if (istat & IDT77105_ISTAT_RSCC) {
222 /* Rx Signal Condition Change - line went up or down */
223 if (istat & IDT77105_ISTAT_GOODSIG) { /* signal detected again */
224 /* This should not happen (restart timer does it) but JIC */
225 atm_dev_signal_change(dev, ATM_PHY_SIG_FOUND);
226 } else { /* signal lost */
227 /*
228 * Disable interrupts and stop all transmission and
229 * reception - the restart timer will restore these.
230 */
231 PRIV(dev)->old_mcr = GET(MCR);
232 PUT(
233 (PRIV(dev)->old_mcr|
234 IDT77105_MCR_DREC|
235 IDT77105_MCR_DRIC|
236 IDT77105_MCR_HALTTX
237 ) & ~IDT77105_MCR_EIP, MCR);
238 atm_dev_signal_change(dev, ATM_PHY_SIG_LOST);
239 printk(KERN_NOTICE "%s(itf %d): signal lost\n",
240 dev->type,dev->number);
241 }
242 }
243
244 if (istat & IDT77105_ISTAT_RFO) {
245 /* Rx FIFO Overrun -- perform a FIFO flush */
246 PUT( GET(DIAG) | IDT77105_DIAG_RFLUSH, DIAG);
247 printk(KERN_NOTICE "%s(itf %d): receive FIFO overrun\n",
248 dev->type,dev->number);
249 }
250 #ifdef GENERAL_DEBUG
251 if (istat & (IDT77105_ISTAT_HECERR | IDT77105_ISTAT_SCR |
252 IDT77105_ISTAT_RSE)) {
253 /* normally don't care - just report in stats */
254 printk(KERN_NOTICE "%s(itf %d): received cell with error\n",
255 dev->type,dev->number);
256 }
257 #endif
258 }
259
260
idt77105_start(struct atm_dev * dev)261 static int idt77105_start(struct atm_dev *dev)
262 {
263 unsigned long flags;
264
265 if (!(dev->phy_data = kmalloc(sizeof(struct idt77105_priv),GFP_KERNEL)))
266 return -ENOMEM;
267 PRIV(dev)->dev = dev;
268 spin_lock_irqsave(&idt77105_priv_lock, flags);
269 PRIV(dev)->next = idt77105_all;
270 idt77105_all = PRIV(dev);
271 spin_unlock_irqrestore(&idt77105_priv_lock, flags);
272 memset(&PRIV(dev)->stats,0,sizeof(struct idt77105_stats));
273
274 /* initialise dev->signal from Good Signal Bit */
275 atm_dev_signal_change(dev,
276 GET(ISTAT) & IDT77105_ISTAT_GOODSIG ?
277 ATM_PHY_SIG_FOUND : ATM_PHY_SIG_LOST);
278 if (dev->signal == ATM_PHY_SIG_LOST)
279 printk(KERN_WARNING "%s(itf %d): no signal\n",dev->type,
280 dev->number);
281
282 /* initialise loop mode from hardware */
283 switch ( GET(DIAG) & IDT77105_DIAG_LCMASK ) {
284 case IDT77105_DIAG_LC_NORMAL:
285 PRIV(dev)->loop_mode = ATM_LM_NONE;
286 break;
287 case IDT77105_DIAG_LC_PHY_LOOPBACK:
288 PRIV(dev)->loop_mode = ATM_LM_LOC_ATM;
289 break;
290 case IDT77105_DIAG_LC_LINE_LOOPBACK:
291 PRIV(dev)->loop_mode = ATM_LM_RMT_ATM;
292 break;
293 }
294
295 /* enable interrupts, e.g. on loss of signal */
296 PRIV(dev)->old_mcr = GET(MCR);
297 if (dev->signal == ATM_PHY_SIG_FOUND) {
298 PRIV(dev)->old_mcr |= IDT77105_MCR_EIP;
299 PUT(PRIV(dev)->old_mcr, MCR);
300 }
301
302
303 idt77105_stats_timer_func(0); /* clear 77105 counters */
304 (void) fetch_stats(dev,NULL,1); /* clear kernel counters */
305
306 spin_lock_irqsave(&idt77105_priv_lock, flags);
307 if (start_timer) {
308 start_timer = 0;
309
310 stats_timer.expires = jiffies+IDT77105_STATS_TIMER_PERIOD;
311 add_timer(&stats_timer);
312
313 restart_timer.expires = jiffies+IDT77105_RESTART_TIMER_PERIOD;
314 add_timer(&restart_timer);
315 }
316 spin_unlock_irqrestore(&idt77105_priv_lock, flags);
317 return 0;
318 }
319
320
idt77105_stop(struct atm_dev * dev)321 static int idt77105_stop(struct atm_dev *dev)
322 {
323 struct idt77105_priv *walk, *prev;
324
325 DPRINTK("%s(itf %d): stopping IDT77105\n",dev->type,dev->number);
326
327 /* disable interrupts */
328 PUT( GET(MCR) & ~IDT77105_MCR_EIP, MCR );
329
330 /* detach private struct from atm_dev & free */
331 for (prev = NULL, walk = idt77105_all ;
332 walk != NULL;
333 prev = walk, walk = walk->next) {
334 if (walk->dev == dev) {
335 if (prev != NULL)
336 prev->next = walk->next;
337 else
338 idt77105_all = walk->next;
339 dev->phy = NULL;
340 dev->phy_data = NULL;
341 kfree(walk);
342 break;
343 }
344 }
345
346 return 0;
347 }
348
349
350 static const struct atmphy_ops idt77105_ops = {
351 .start = idt77105_start,
352 .ioctl = idt77105_ioctl,
353 .interrupt = idt77105_int,
354 .stop = idt77105_stop,
355 };
356
357
idt77105_init(struct atm_dev * dev)358 int idt77105_init(struct atm_dev *dev)
359 {
360 dev->phy = &idt77105_ops;
361 return 0;
362 }
363
364 EXPORT_SYMBOL(idt77105_init);
365
idt77105_exit(void)366 static void __exit idt77105_exit(void)
367 {
368 /* turn off timers */
369 del_timer_sync(&stats_timer);
370 del_timer_sync(&restart_timer);
371 }
372
373 module_exit(idt77105_exit);
374
375 MODULE_LICENSE("GPL");
376