xref: /openbmc/linux/drivers/input/serio/hp_sdc_mlc.c (revision 4e57b681)
1 /*
2  * Access to HP-HIL MLC through HP System Device Controller.
3  *
4  * Copyright (c) 2001 Brian S. Julin
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions, and the following disclaimer,
12  *    without modification.
13  * 2. The name of the author may not be used to endorse or promote products
14  *    derived from this software without specific prior written permission.
15  *
16  * Alternatively, this software may be distributed under the terms of the
17  * GNU General Public License ("GPL").
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
23  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  *
29  * References:
30  * HP-HIL Technical Reference Manual.  Hewlett Packard Product No. 45918A
31  * System Device Controller Microprocessor Firmware Theory of Operation
32  *      for Part Number 1820-4784 Revision B.  Dwg No. A-1820-4784-2
33  *
34  */
35 
36 #include <linux/hil_mlc.h>
37 #include <linux/hp_sdc.h>
38 #include <linux/errno.h>
39 #include <linux/kernel.h>
40 #include <linux/module.h>
41 #include <linux/init.h>
42 #include <linux/string.h>
43 #include <asm/semaphore.h>
44 
45 #define PREFIX "HP SDC MLC: "
46 
47 static hil_mlc hp_sdc_mlc;
48 
49 MODULE_AUTHOR("Brian S. Julin <bri@calyx.com>");
50 MODULE_DESCRIPTION("Glue for onboard HIL MLC in HP-PARISC machines");
51 MODULE_LICENSE("Dual BSD/GPL");
52 
53 struct hp_sdc_mlc_priv_s {
54 	int emtestmode;
55 	hp_sdc_transaction trans;
56 	u8 tseq[16];
57 	int got5x;
58 } hp_sdc_mlc_priv;
59 
60 /************************* Interrupt context ******************************/
61 static void hp_sdc_mlc_isr (int irq, void *dev_id,
62 			    uint8_t status, uint8_t data) {
63   	int idx;
64 	hil_mlc *mlc = &hp_sdc_mlc;
65 
66 	write_lock(&(mlc->lock));
67 	if (mlc->icount < 0) {
68 		printk(KERN_WARNING PREFIX "HIL Overflow!\n");
69 		up(&mlc->isem);
70 		goto out;
71 	}
72 	idx = 15 - mlc->icount;
73 	if ((status & HP_SDC_STATUS_IRQMASK) == HP_SDC_STATUS_HILDATA) {
74 		mlc->ipacket[idx] |= data | HIL_ERR_INT;
75 		mlc->icount--;
76 		if (hp_sdc_mlc_priv.got5x) goto check;
77 		if (!idx) goto check;
78 		if ((mlc->ipacket[idx-1] & HIL_PKT_ADDR_MASK) !=
79 		    (mlc->ipacket[idx] & HIL_PKT_ADDR_MASK)) {
80 			mlc->ipacket[idx] &= ~HIL_PKT_ADDR_MASK;
81 			mlc->ipacket[idx] |= (mlc->ipacket[idx-1]
82 						    & HIL_PKT_ADDR_MASK);
83 		}
84 		goto check;
85 	}
86 	/* We know status is 5X */
87 	if (data & HP_SDC_HIL_ISERR) goto err;
88 	mlc->ipacket[idx] =
89 		(data & HP_SDC_HIL_R1MASK) << HIL_PKT_ADDR_SHIFT;
90 	hp_sdc_mlc_priv.got5x = 1;
91 	goto out;
92 
93  check:
94 	hp_sdc_mlc_priv.got5x = 0;
95 	if (mlc->imatch == 0) goto done;
96 	if ((mlc->imatch == (HIL_ERR_INT | HIL_PKT_CMD | HIL_CMD_POL))
97 	    && (mlc->ipacket[idx] == (mlc->imatch | idx))) goto done;
98 	if (mlc->ipacket[idx] == mlc->imatch) goto done;
99 	goto out;
100 
101  err:
102 	printk(KERN_DEBUG PREFIX "err code %x\n", data);
103 	switch (data) {
104 	case HP_SDC_HIL_RC_DONE:
105 		printk(KERN_WARNING PREFIX "Bastard SDC reconfigured loop!\n");
106 		break;
107 	case HP_SDC_HIL_ERR:
108 		mlc->ipacket[idx] |= HIL_ERR_INT | HIL_ERR_PERR |
109 		  HIL_ERR_FERR | HIL_ERR_FOF;
110 		break;
111 	case HP_SDC_HIL_TO:
112 		mlc->ipacket[idx] |= HIL_ERR_INT | HIL_ERR_LERR;
113 		break;
114 	case HP_SDC_HIL_RC:
115 		printk(KERN_WARNING PREFIX "Bastard SDC decided to reconfigure loop!\n");
116 		break;
117 	default:
118 		printk(KERN_WARNING PREFIX "Unkown HIL Error status (%x)!\n", data);
119 		break;
120 	}
121 	/* No more data will be coming due to an error. */
122  done:
123 	tasklet_schedule(mlc->tasklet);
124 	up(&(mlc->isem));
125  out:
126 	write_unlock(&(mlc->lock));
127 }
128 
129 
130 /******************** Tasklet or userspace context functions ****************/
131 
132 static int hp_sdc_mlc_in (hil_mlc *mlc, suseconds_t timeout) {
133 	unsigned long flags;
134 	struct hp_sdc_mlc_priv_s *priv;
135 	int rc = 2;
136 
137 	priv = mlc->priv;
138 
139 	write_lock_irqsave(&(mlc->lock), flags);
140 
141 	/* Try to down the semaphore */
142 	if (down_trylock(&(mlc->isem))) {
143 		struct timeval tv;
144 		if (priv->emtestmode) {
145 			mlc->ipacket[0] =
146 				HIL_ERR_INT | (mlc->opacket &
147 					       (HIL_PKT_CMD |
148 						HIL_PKT_ADDR_MASK |
149 						HIL_PKT_DATA_MASK));
150 			mlc->icount = 14;
151 			/* printk(KERN_DEBUG PREFIX ">[%x]\n", mlc->ipacket[0]); */
152 			goto wasup;
153 		}
154 		do_gettimeofday(&tv);
155 		tv.tv_usec += 1000000 * (tv.tv_sec - mlc->instart.tv_sec);
156 		if (tv.tv_usec - mlc->instart.tv_usec > mlc->intimeout) {
157 		  /*		  printk("!%i %i",
158 				  tv.tv_usec - mlc->instart.tv_usec,
159 				  mlc->intimeout);
160 		  */
161 			rc = 1;
162 			up(&(mlc->isem));
163 		}
164 		goto done;
165 	}
166  wasup:
167 	up(&(mlc->isem));
168 	rc = 0;
169 	goto done;
170  done:
171 	write_unlock_irqrestore(&(mlc->lock), flags);
172 	return rc;
173 }
174 
175 static int hp_sdc_mlc_cts (hil_mlc *mlc) {
176 	struct hp_sdc_mlc_priv_s *priv;
177 	unsigned long flags;
178 
179 	priv = mlc->priv;
180 
181 	write_lock_irqsave(&(mlc->lock), flags);
182 
183 	/* Try to down the semaphores -- they should be up. */
184 	if (down_trylock(&(mlc->isem))) {
185 		BUG();
186 		goto busy;
187 	}
188 	if (down_trylock(&(mlc->osem))) {
189 	 	BUG();
190 		up(&(mlc->isem));
191 		goto busy;
192 	}
193 	up(&(mlc->isem));
194 	up(&(mlc->osem));
195 
196 	if (down_trylock(&(mlc->csem))) {
197 		if (priv->trans.act.semaphore != &(mlc->csem)) goto poll;
198 		goto busy;
199 	}
200 	if (!(priv->tseq[4] & HP_SDC_USE_LOOP)) goto done;
201 
202  poll:
203 	priv->trans.act.semaphore = &(mlc->csem);
204 	priv->trans.actidx = 0;
205 	priv->trans.idx = 1;
206 	priv->trans.endidx = 5;
207 	priv->tseq[0] =
208 		HP_SDC_ACT_POSTCMD | HP_SDC_ACT_DATAIN | HP_SDC_ACT_SEMAPHORE;
209 	priv->tseq[1] = HP_SDC_CMD_READ_USE;
210 	priv->tseq[2] = 1;
211 	priv->tseq[3] = 0;
212 	priv->tseq[4] = 0;
213 	hp_sdc_enqueue_transaction(&(priv->trans));
214  busy:
215 	write_unlock_irqrestore(&(mlc->lock), flags);
216 	return 1;
217  done:
218 	priv->trans.act.semaphore = &(mlc->osem);
219 	up(&(mlc->csem));
220 	write_unlock_irqrestore(&(mlc->lock), flags);
221 	return 0;
222 }
223 
224 static void hp_sdc_mlc_out (hil_mlc *mlc) {
225 	struct hp_sdc_mlc_priv_s *priv;
226 	unsigned long flags;
227 
228 	priv = mlc->priv;
229 
230 	write_lock_irqsave(&(mlc->lock), flags);
231 
232 	/* Try to down the semaphore -- it should be up. */
233 	if (down_trylock(&(mlc->osem))) {
234 	 	BUG();
235 		goto done;
236 	}
237 
238 	if (mlc->opacket & HIL_DO_ALTER_CTRL) goto do_control;
239 
240  do_data:
241 	if (priv->emtestmode) {
242 		up(&(mlc->osem));
243 		goto done;
244 	}
245 	/* Shouldn't be sending commands when loop may be busy */
246 	if (down_trylock(&(mlc->csem))) {
247 	 	BUG();
248 		goto done;
249 	}
250 	up(&(mlc->csem));
251 
252 	priv->trans.actidx = 0;
253 	priv->trans.idx = 1;
254 	priv->trans.act.semaphore = &(mlc->osem);
255 	priv->trans.endidx = 6;
256 	priv->tseq[0] =
257 		HP_SDC_ACT_DATAREG | HP_SDC_ACT_POSTCMD | HP_SDC_ACT_SEMAPHORE;
258 	priv->tseq[1] = 0x7;
259 	priv->tseq[2] =
260 		(mlc->opacket &
261 		 (HIL_PKT_ADDR_MASK | HIL_PKT_CMD))
262 		   >> HIL_PKT_ADDR_SHIFT;
263 	priv->tseq[3] =
264 		(mlc->opacket & HIL_PKT_DATA_MASK)
265 		  >> HIL_PKT_DATA_SHIFT;
266 	priv->tseq[4] = 0;  /* No timeout */
267 	if (priv->tseq[3] == HIL_CMD_DHR) priv->tseq[4] = 1;
268 	priv->tseq[5] = HP_SDC_CMD_DO_HIL;
269 	goto enqueue;
270 
271  do_control:
272 	priv->emtestmode = mlc->opacket & HIL_CTRL_TEST;
273 	if ((mlc->opacket & (HIL_CTRL_APE | HIL_CTRL_IPF)) == HIL_CTRL_APE) {
274 		BUG(); /* we cannot emulate this, it should not be used. */
275 	}
276 	if ((mlc->opacket & HIL_CTRL_ONLY) == HIL_CTRL_ONLY) goto control_only;
277 	if (mlc->opacket & HIL_CTRL_APE) {
278 		BUG(); /* Should not send command/data after engaging APE */
279 		goto done;
280 	}
281 	/* Disengaging APE this way would not be valid either since
282 	 * the loop must be allowed to idle.
283 	 *
284 	 * So, it works out that we really never actually send control
285 	 * and data when using SDC, we just send the data.
286 	 */
287 	goto do_data;
288 
289  control_only:
290 	priv->trans.actidx = 0;
291 	priv->trans.idx = 1;
292 	priv->trans.act.semaphore = &(mlc->osem);
293 	priv->trans.endidx = 4;
294 	priv->tseq[0] =
295 	  HP_SDC_ACT_PRECMD | HP_SDC_ACT_DATAOUT | HP_SDC_ACT_SEMAPHORE;
296 	priv->tseq[1] = HP_SDC_CMD_SET_LPC;
297 	priv->tseq[2] = 1;
298 	//	priv->tseq[3] = (mlc->ddc + 1) | HP_SDC_LPS_ACSUCC;
299 	priv->tseq[3] = 0;
300 	if (mlc->opacket & HIL_CTRL_APE) {
301 		priv->tseq[3] |= HP_SDC_LPC_APE_IPF;
302 		down_trylock(&(mlc->csem));
303 	}
304  enqueue:
305 	hp_sdc_enqueue_transaction(&(priv->trans));
306  done:
307 	write_unlock_irqrestore(&(mlc->lock), flags);
308 }
309 
310 static int __init hp_sdc_mlc_init(void)
311 {
312 	hil_mlc *mlc = &hp_sdc_mlc;
313 
314 	printk(KERN_INFO PREFIX "Registering the System Domain Controller's HIL MLC.\n");
315 
316 	hp_sdc_mlc_priv.emtestmode = 0;
317 	hp_sdc_mlc_priv.trans.seq = hp_sdc_mlc_priv.tseq;
318 	hp_sdc_mlc_priv.trans.act.semaphore = &(mlc->osem);
319 	hp_sdc_mlc_priv.got5x = 0;
320 
321 	mlc->cts		= &hp_sdc_mlc_cts;
322 	mlc->in			= &hp_sdc_mlc_in;
323 	mlc->out		= &hp_sdc_mlc_out;
324 
325 	if (hil_mlc_register(mlc)) {
326 		printk(KERN_WARNING PREFIX "Failed to register MLC structure with hil_mlc\n");
327 		goto err0;
328 	}
329 	mlc->priv		= &hp_sdc_mlc_priv;
330 
331 	if (hp_sdc_request_hil_irq(&hp_sdc_mlc_isr)) {
332 		printk(KERN_WARNING PREFIX "Request for raw HIL ISR hook denied\n");
333 		goto err1;
334 	}
335 	return 0;
336  err1:
337 	if (hil_mlc_unregister(mlc)) {
338 		printk(KERN_ERR PREFIX "Failed to unregister MLC structure with hil_mlc.\n"
339 			"This is bad.  Could cause an oops.\n");
340 	}
341  err0:
342 	return -EBUSY;
343 }
344 
345 static void __exit hp_sdc_mlc_exit(void)
346 {
347 	hil_mlc *mlc = &hp_sdc_mlc;
348 	if (hp_sdc_release_hil_irq(&hp_sdc_mlc_isr)) {
349 		printk(KERN_ERR PREFIX "Failed to release the raw HIL ISR hook.\n"
350 			"This is bad.  Could cause an oops.\n");
351 	}
352 	if (hil_mlc_unregister(mlc)) {
353 		printk(KERN_ERR PREFIX "Failed to unregister MLC structure with hil_mlc.\n"
354 			"This is bad.  Could cause an oops.\n");
355 	}
356 }
357 
358 module_init(hp_sdc_mlc_init);
359 module_exit(hp_sdc_mlc_exit);
360