hp_sdc_mlc.c

  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
 47static hil_mlc hp_sdc_mlc;
 48
 49MODULE_AUTHOR("Brian S. Julin <bri@calyx.com>");
 50MODULE_DESCRIPTION("Glue for onboard HIL MLC in HP-PARISC machines");
 51MODULE_LICENSE("Dual BSD/GPL");
 52
 53static 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 ******************************/
 61static 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
143static 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
179static 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
222static 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
302static 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
341static 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
354module_init(hp_sdc_mlc_init);
355module_exit(hp_sdc_mlc_exit);