xref: /openbmc/linux/drivers/input/serio/hp_sdc_mlc.c (revision 4f6cce39)
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 <linux/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 static 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 {
64 	int idx;
65 	hil_mlc *mlc = &hp_sdc_mlc;
66 
67 	write_lock(&mlc->lock);
68 	if (mlc->icount < 0) {
69 		printk(KERN_WARNING PREFIX "HIL Overflow!\n");
70 		up(&mlc->isem);
71 		goto out;
72 	}
73 	idx = 15 - mlc->icount;
74 	if ((status & HP_SDC_STATUS_IRQMASK) == HP_SDC_STATUS_HILDATA) {
75 		mlc->ipacket[idx] |= data | HIL_ERR_INT;
76 		mlc->icount--;
77 		if (hp_sdc_mlc_priv.got5x || !idx)
78 			goto check;
79 		if ((mlc->ipacket[idx - 1] & HIL_PKT_ADDR_MASK) !=
80 		    (mlc->ipacket[idx] & HIL_PKT_ADDR_MASK)) {
81 			mlc->ipacket[idx] &= ~HIL_PKT_ADDR_MASK;
82 			mlc->ipacket[idx] |= (mlc->ipacket[idx - 1]
83 						& HIL_PKT_ADDR_MASK);
84 		}
85 		goto check;
86 	}
87 	/* We know status is 5X */
88 	if (data & HP_SDC_HIL_ISERR)
89 		goto err;
90 	mlc->ipacket[idx] =
91 		(data & HP_SDC_HIL_R1MASK) << HIL_PKT_ADDR_SHIFT;
92 	hp_sdc_mlc_priv.got5x = 1;
93 	goto out;
94 
95  check:
96 	hp_sdc_mlc_priv.got5x = 0;
97 	if (mlc->imatch == 0)
98 		goto done;
99 	if ((mlc->imatch == (HIL_ERR_INT | HIL_PKT_CMD | HIL_CMD_POL))
100 	    && (mlc->ipacket[idx] == (mlc->imatch | idx)))
101 		goto done;
102 	if (mlc->ipacket[idx] == mlc->imatch)
103 		goto done;
104 	goto out;
105 
106  err:
107 	printk(KERN_DEBUG PREFIX "err code %x\n", data);
108 
109 	switch (data) {
110 	case HP_SDC_HIL_RC_DONE:
111 		printk(KERN_WARNING PREFIX "Bastard SDC reconfigured loop!\n");
112 		break;
113 
114 	case HP_SDC_HIL_ERR:
115 		mlc->ipacket[idx] |= HIL_ERR_INT | HIL_ERR_PERR |
116 					HIL_ERR_FERR | HIL_ERR_FOF;
117 		break;
118 
119 	case HP_SDC_HIL_TO:
120 		mlc->ipacket[idx] |= HIL_ERR_INT | HIL_ERR_LERR;
121 		break;
122 
123 	case HP_SDC_HIL_RC:
124 		printk(KERN_WARNING PREFIX "Bastard SDC decided to reconfigure loop!\n");
125 		break;
126 
127 	default:
128 		printk(KERN_WARNING PREFIX "Unknown HIL Error status (%x)!\n", data);
129 		break;
130 	}
131 
132 	/* No more data will be coming due to an error. */
133  done:
134 	tasklet_schedule(mlc->tasklet);
135 	up(&mlc->isem);
136  out:
137 	write_unlock(&mlc->lock);
138 }
139 
140 
141 /******************** Tasklet or userspace context functions ****************/
142 
143 static int hp_sdc_mlc_in(hil_mlc *mlc, suseconds_t timeout)
144 {
145 	struct hp_sdc_mlc_priv_s *priv;
146 	int rc = 2;
147 
148 	priv = mlc->priv;
149 
150 	/* Try to down the semaphore */
151 	if (down_trylock(&mlc->isem)) {
152 		struct timeval tv;
153 		if (priv->emtestmode) {
154 			mlc->ipacket[0] =
155 				HIL_ERR_INT | (mlc->opacket &
156 					       (HIL_PKT_CMD |
157 						HIL_PKT_ADDR_MASK |
158 						HIL_PKT_DATA_MASK));
159 			mlc->icount = 14;
160 			/* printk(KERN_DEBUG PREFIX ">[%x]\n", mlc->ipacket[0]); */
161 			goto wasup;
162 		}
163 		do_gettimeofday(&tv);
164 		tv.tv_usec += USEC_PER_SEC * (tv.tv_sec - mlc->instart.tv_sec);
165 		if (tv.tv_usec - mlc->instart.tv_usec > mlc->intimeout) {
166 			/*	printk("!%i %i",
167 				tv.tv_usec - mlc->instart.tv_usec,
168 				mlc->intimeout);
169 			 */
170 			rc = 1;
171 			up(&mlc->isem);
172 		}
173 		goto done;
174 	}
175  wasup:
176 	up(&mlc->isem);
177 	rc = 0;
178  done:
179 	return rc;
180 }
181 
182 static int hp_sdc_mlc_cts(hil_mlc *mlc)
183 {
184 	struct hp_sdc_mlc_priv_s *priv;
185 
186 	priv = mlc->priv;
187 
188 	/* Try to down the semaphores -- they should be up. */
189 	BUG_ON(down_trylock(&mlc->isem));
190 	BUG_ON(down_trylock(&mlc->osem));
191 
192 	up(&mlc->isem);
193 	up(&mlc->osem);
194 
195 	if (down_trylock(&mlc->csem)) {
196 		if (priv->trans.act.semaphore != &mlc->csem)
197 			goto poll;
198 		else
199 			goto busy;
200 	}
201 
202 	if (!(priv->tseq[4] & HP_SDC_USE_LOOP))
203 		goto done;
204 
205  poll:
206 	priv->trans.act.semaphore = &mlc->csem;
207 	priv->trans.actidx = 0;
208 	priv->trans.idx = 1;
209 	priv->trans.endidx = 5;
210 	priv->tseq[0] =
211 		HP_SDC_ACT_POSTCMD | HP_SDC_ACT_DATAIN | HP_SDC_ACT_SEMAPHORE;
212 	priv->tseq[1] = HP_SDC_CMD_READ_USE;
213 	priv->tseq[2] = 1;
214 	priv->tseq[3] = 0;
215 	priv->tseq[4] = 0;
216 	__hp_sdc_enqueue_transaction(&priv->trans);
217  busy:
218 	return 1;
219  done:
220 	priv->trans.act.semaphore = &mlc->osem;
221 	up(&mlc->csem);
222 	return 0;
223 }
224 
225 static void hp_sdc_mlc_out(hil_mlc *mlc)
226 {
227 	struct hp_sdc_mlc_priv_s *priv;
228 
229 	priv = mlc->priv;
230 
231 	/* Try to down the semaphore -- it should be up. */
232 	BUG_ON(down_trylock(&mlc->osem));
233 
234 	if (mlc->opacket & HIL_DO_ALTER_CTRL)
235 		goto do_control;
236 
237  do_data:
238 	if (priv->emtestmode) {
239 		up(&mlc->osem);
240 		return;
241 	}
242 	/* Shouldn't be sending commands when loop may be busy */
243 	BUG_ON(down_trylock(&mlc->csem));
244 	up(&mlc->csem);
245 
246 	priv->trans.actidx = 0;
247 	priv->trans.idx = 1;
248 	priv->trans.act.semaphore = &mlc->osem;
249 	priv->trans.endidx = 6;
250 	priv->tseq[0] =
251 		HP_SDC_ACT_DATAREG | HP_SDC_ACT_POSTCMD | HP_SDC_ACT_SEMAPHORE;
252 	priv->tseq[1] = 0x7;
253 	priv->tseq[2] =
254 		(mlc->opacket &
255 		 (HIL_PKT_ADDR_MASK | HIL_PKT_CMD))
256 		   >> HIL_PKT_ADDR_SHIFT;
257 	priv->tseq[3] =
258 		(mlc->opacket & HIL_PKT_DATA_MASK)
259 		  >> HIL_PKT_DATA_SHIFT;
260 	priv->tseq[4] = 0;  /* No timeout */
261 	if (priv->tseq[3] == HIL_CMD_DHR)
262 		priv->tseq[4] = 1;
263 	priv->tseq[5] = HP_SDC_CMD_DO_HIL;
264 	goto enqueue;
265 
266  do_control:
267 	priv->emtestmode = mlc->opacket & HIL_CTRL_TEST;
268 
269 	/* we cannot emulate this, it should not be used. */
270 	BUG_ON((mlc->opacket & (HIL_CTRL_APE | HIL_CTRL_IPF)) == HIL_CTRL_APE);
271 
272 	if ((mlc->opacket & HIL_CTRL_ONLY) == HIL_CTRL_ONLY)
273 		goto control_only;
274 
275 	/* Should not send command/data after engaging APE */
276 	BUG_ON(mlc->opacket & HIL_CTRL_APE);
277 
278 	/* Disengaging APE this way would not be valid either since
279 	 * the loop must be allowed to idle.
280 	 *
281 	 * So, it works out that we really never actually send control
282 	 * and data when using SDC, we just send the data.
283 	 */
284 	goto do_data;
285 
286  control_only:
287 	priv->trans.actidx = 0;
288 	priv->trans.idx = 1;
289 	priv->trans.act.semaphore = &mlc->osem;
290 	priv->trans.endidx = 4;
291 	priv->tseq[0] =
292 	  HP_SDC_ACT_PRECMD | HP_SDC_ACT_DATAOUT | HP_SDC_ACT_SEMAPHORE;
293 	priv->tseq[1] = HP_SDC_CMD_SET_LPC;
294 	priv->tseq[2] = 1;
295 	/* priv->tseq[3] = (mlc->ddc + 1) | HP_SDC_LPS_ACSUCC; */
296 	priv->tseq[3] = 0;
297 	if (mlc->opacket & HIL_CTRL_APE) {
298 		priv->tseq[3] |= HP_SDC_LPC_APE_IPF;
299 		BUG_ON(down_trylock(&mlc->csem));
300 	}
301  enqueue:
302 	hp_sdc_enqueue_transaction(&priv->trans);
303 }
304 
305 static int __init hp_sdc_mlc_init(void)
306 {
307 	hil_mlc *mlc = &hp_sdc_mlc;
308 	int err;
309 
310 #ifdef __mc68000__
311 	if (!MACH_IS_HP300)
312 		return -ENODEV;
313 #endif
314 
315 	printk(KERN_INFO PREFIX "Registering the System Domain Controller's HIL MLC.\n");
316 
317 	hp_sdc_mlc_priv.emtestmode = 0;
318 	hp_sdc_mlc_priv.trans.seq = hp_sdc_mlc_priv.tseq;
319 	hp_sdc_mlc_priv.trans.act.semaphore = &mlc->osem;
320 	hp_sdc_mlc_priv.got5x = 0;
321 
322 	mlc->cts = &hp_sdc_mlc_cts;
323 	mlc->in	= &hp_sdc_mlc_in;
324 	mlc->out = &hp_sdc_mlc_out;
325 	mlc->priv = &hp_sdc_mlc_priv;
326 
327 	err = hil_mlc_register(mlc);
328 	if (err) {
329 		printk(KERN_WARNING PREFIX "Failed to register MLC structure with hil_mlc\n");
330 		return err;
331 	}
332 
333 	if (hp_sdc_request_hil_irq(&hp_sdc_mlc_isr)) {
334 		printk(KERN_WARNING PREFIX "Request for raw HIL ISR hook denied\n");
335 		if (hil_mlc_unregister(mlc))
336 			printk(KERN_ERR PREFIX "Failed to unregister MLC structure with hil_mlc.\n"
337 				"This is bad.  Could cause an oops.\n");
338 		return -EBUSY;
339 	}
340 
341 	return 0;
342 }
343 
344 static void __exit hp_sdc_mlc_exit(void)
345 {
346 	hil_mlc *mlc = &hp_sdc_mlc;
347 
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 module_init(hp_sdc_mlc_init);
358 module_exit(hp_sdc_mlc_exit);
359