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