xref: /openbmc/linux/drivers/input/serio/hp_sdc_mlc.c (revision 2cf1c348)
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 		if (priv->emtestmode) {
153 			mlc->ipacket[0] =
154 				HIL_ERR_INT | (mlc->opacket &
155 					       (HIL_PKT_CMD |
156 						HIL_PKT_ADDR_MASK |
157 						HIL_PKT_DATA_MASK));
158 			mlc->icount = 14;
159 			/* printk(KERN_DEBUG PREFIX ">[%x]\n", mlc->ipacket[0]); */
160 			goto wasup;
161 		}
162 		if (time_after(jiffies, mlc->instart + mlc->intimeout)) {
163 			/*	printk("!%i %i",
164 				tv.tv_usec - mlc->instart.tv_usec,
165 				mlc->intimeout);
166 			 */
167 			rc = 1;
168 			up(&mlc->isem);
169 		}
170 		goto done;
171 	}
172  wasup:
173 	up(&mlc->isem);
174 	rc = 0;
175  done:
176 	return rc;
177 }
178 
179 static int hp_sdc_mlc_cts(hil_mlc *mlc)
180 {
181 	struct hp_sdc_mlc_priv_s *priv;
182 
183 	priv = mlc->priv;
184 
185 	/* Try to down the semaphores -- they should be up. */
186 	BUG_ON(down_trylock(&mlc->isem));
187 	BUG_ON(down_trylock(&mlc->osem));
188 
189 	up(&mlc->isem);
190 	up(&mlc->osem);
191 
192 	if (down_trylock(&mlc->csem)) {
193 		if (priv->trans.act.semaphore != &mlc->csem)
194 			goto poll;
195 		else
196 			goto busy;
197 	}
198 
199 	if (!(priv->tseq[4] & HP_SDC_USE_LOOP))
200 		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 	return __hp_sdc_enqueue_transaction(&priv->trans);
214  busy:
215 	return 1;
216  done:
217 	priv->trans.act.semaphore = &mlc->osem;
218 	up(&mlc->csem);
219 	return 0;
220 }
221 
222 static int hp_sdc_mlc_out(hil_mlc *mlc)
223 {
224 	struct hp_sdc_mlc_priv_s *priv;
225 
226 	priv = mlc->priv;
227 
228 	/* Try to down the semaphore -- it should be up. */
229 	BUG_ON(down_trylock(&mlc->osem));
230 
231 	if (mlc->opacket & HIL_DO_ALTER_CTRL)
232 		goto do_control;
233 
234  do_data:
235 	if (priv->emtestmode) {
236 		up(&mlc->osem);
237 		return 0;
238 	}
239 	/* Shouldn't be sending commands when loop may be busy */
240 	BUG_ON(down_trylock(&mlc->csem));
241 	up(&mlc->csem);
242 
243 	priv->trans.actidx = 0;
244 	priv->trans.idx = 1;
245 	priv->trans.act.semaphore = &mlc->osem;
246 	priv->trans.endidx = 6;
247 	priv->tseq[0] =
248 		HP_SDC_ACT_DATAREG | HP_SDC_ACT_POSTCMD | HP_SDC_ACT_SEMAPHORE;
249 	priv->tseq[1] = 0x7;
250 	priv->tseq[2] =
251 		(mlc->opacket &
252 		 (HIL_PKT_ADDR_MASK | HIL_PKT_CMD))
253 		   >> HIL_PKT_ADDR_SHIFT;
254 	priv->tseq[3] =
255 		(mlc->opacket & HIL_PKT_DATA_MASK)
256 		  >> HIL_PKT_DATA_SHIFT;
257 	priv->tseq[4] = 0;  /* No timeout */
258 	if (priv->tseq[3] == HIL_CMD_DHR)
259 		priv->tseq[4] = 1;
260 	priv->tseq[5] = HP_SDC_CMD_DO_HIL;
261 	goto enqueue;
262 
263  do_control:
264 	priv->emtestmode = mlc->opacket & HIL_CTRL_TEST;
265 
266 	/* we cannot emulate this, it should not be used. */
267 	BUG_ON((mlc->opacket & (HIL_CTRL_APE | HIL_CTRL_IPF)) == HIL_CTRL_APE);
268 
269 	if ((mlc->opacket & HIL_CTRL_ONLY) == HIL_CTRL_ONLY)
270 		goto control_only;
271 
272 	/* Should not send command/data after engaging APE */
273 	BUG_ON(mlc->opacket & HIL_CTRL_APE);
274 
275 	/* Disengaging APE this way would not be valid either since
276 	 * the loop must be allowed to idle.
277 	 *
278 	 * So, it works out that we really never actually send control
279 	 * and data when using SDC, we just send the data.
280 	 */
281 	goto do_data;
282 
283  control_only:
284 	priv->trans.actidx = 0;
285 	priv->trans.idx = 1;
286 	priv->trans.act.semaphore = &mlc->osem;
287 	priv->trans.endidx = 4;
288 	priv->tseq[0] =
289 	  HP_SDC_ACT_PRECMD | HP_SDC_ACT_DATAOUT | HP_SDC_ACT_SEMAPHORE;
290 	priv->tseq[1] = HP_SDC_CMD_SET_LPC;
291 	priv->tseq[2] = 1;
292 	/* priv->tseq[3] = (mlc->ddc + 1) | HP_SDC_LPS_ACSUCC; */
293 	priv->tseq[3] = 0;
294 	if (mlc->opacket & HIL_CTRL_APE) {
295 		priv->tseq[3] |= HP_SDC_LPC_APE_IPF;
296 		BUG_ON(down_trylock(&mlc->csem));
297 	}
298  enqueue:
299 	return hp_sdc_enqueue_transaction(&priv->trans);
300 }
301 
302 static int __init hp_sdc_mlc_init(void)
303 {
304 	hil_mlc *mlc = &hp_sdc_mlc;
305 	int err;
306 
307 #ifdef __mc68000__
308 	if (!MACH_IS_HP300)
309 		return -ENODEV;
310 #endif
311 
312 	printk(KERN_INFO PREFIX "Registering the System Domain Controller's HIL MLC.\n");
313 
314 	hp_sdc_mlc_priv.emtestmode = 0;
315 	hp_sdc_mlc_priv.trans.seq = hp_sdc_mlc_priv.tseq;
316 	hp_sdc_mlc_priv.trans.act.semaphore = &mlc->osem;
317 	hp_sdc_mlc_priv.got5x = 0;
318 
319 	mlc->cts = &hp_sdc_mlc_cts;
320 	mlc->in	= &hp_sdc_mlc_in;
321 	mlc->out = &hp_sdc_mlc_out;
322 	mlc->priv = &hp_sdc_mlc_priv;
323 
324 	err = hil_mlc_register(mlc);
325 	if (err) {
326 		printk(KERN_WARNING PREFIX "Failed to register MLC structure with hil_mlc\n");
327 		return err;
328 	}
329 
330 	if (hp_sdc_request_hil_irq(&hp_sdc_mlc_isr)) {
331 		printk(KERN_WARNING PREFIX "Request for raw HIL ISR hook denied\n");
332 		if (hil_mlc_unregister(mlc))
333 			printk(KERN_ERR PREFIX "Failed to unregister MLC structure with hil_mlc.\n"
334 				"This is bad.  Could cause an oops.\n");
335 		return -EBUSY;
336 	}
337 
338 	return 0;
339 }
340 
341 static void __exit hp_sdc_mlc_exit(void)
342 {
343 	hil_mlc *mlc = &hp_sdc_mlc;
344 
345 	if (hp_sdc_release_hil_irq(&hp_sdc_mlc_isr))
346 		printk(KERN_ERR PREFIX "Failed to release the raw HIL ISR hook.\n"
347 			"This is bad.  Could cause an oops.\n");
348 
349 	if (hil_mlc_unregister(mlc))
350 		printk(KERN_ERR PREFIX "Failed to unregister MLC structure with hil_mlc.\n"
351 			"This is bad.  Could cause an oops.\n");
352 }
353 
354 module_init(hp_sdc_mlc_init);
355 module_exit(hp_sdc_mlc_exit);
356