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
44#define PREFIX "HP SDC MLC: "
45
46static hil_mlc hp_sdc_mlc;
47
48MODULE_AUTHOR("Brian S. Julin <bri@calyx.com>");
49MODULE_DESCRIPTION("Glue for onboard HIL MLC in HP-PARISC machines");
50MODULE_LICENSE("Dual BSD/GPL");
51
52struct hp_sdc_mlc_priv_s {
53	int emtestmode;
54	hp_sdc_transaction trans;
55	u8 tseq[16];
56	int got5x;
57} hp_sdc_mlc_priv;
58
59/************************* Interrupt context ******************************/
60static void hp_sdc_mlc_isr (int irq, void *dev_id,
61			    uint8_t status, uint8_t data) {
62  	int idx;
63	hil_mlc *mlc = &hp_sdc_mlc;
64
65	write_lock(&(mlc->lock));
66	if (mlc->icount < 0) {
67		printk(KERN_WARNING PREFIX "HIL Overflow!\n");
68		up(&mlc->isem);
69		goto out;
70	}
71	idx = 15 - mlc->icount;
72	if ((status & HP_SDC_STATUS_IRQMASK) == HP_SDC_STATUS_HILDATA) {
73		mlc->ipacket[idx] |= data | HIL_ERR_INT;
74		mlc->icount--;
75		if (hp_sdc_mlc_priv.got5x) goto check;
76		if (!idx) goto check;
77		if ((mlc->ipacket[idx-1] & HIL_PKT_ADDR_MASK) !=
78		    (mlc->ipacket[idx] & HIL_PKT_ADDR_MASK)) {
79			mlc->ipacket[idx] &= ~HIL_PKT_ADDR_MASK;
80			mlc->ipacket[idx] |= (mlc->ipacket[idx-1]
81						    & HIL_PKT_ADDR_MASK);
82		}
83		goto check;
84	}
85	/* We know status is 5X */
86	if (data & HP_SDC_HIL_ISERR) goto err;
87	mlc->ipacket[idx] =
88		(data & HP_SDC_HIL_R1MASK) << HIL_PKT_ADDR_SHIFT;
89	hp_sdc_mlc_priv.got5x = 1;
90	goto out;
91
92 check:
93	hp_sdc_mlc_priv.got5x = 0;
94	if (mlc->imatch == 0) goto done;
95	if ((mlc->imatch == (HIL_ERR_INT | HIL_PKT_CMD | HIL_CMD_POL))
96	    && (mlc->ipacket[idx] == (mlc->imatch | idx))) goto done;
97	if (mlc->ipacket[idx] == mlc->imatch) goto done;
98	goto out;
99
100 err:
101	printk(KERN_DEBUG PREFIX "err code %x\n", data);
102	switch (data) {
103	case HP_SDC_HIL_RC_DONE:
104		printk(KERN_WARNING PREFIX "Bastard SDC reconfigured loop!\n");
105		break;
106	case HP_SDC_HIL_ERR:
107		mlc->ipacket[idx] |= HIL_ERR_INT | HIL_ERR_PERR |
108		  HIL_ERR_FERR | HIL_ERR_FOF;
109		break;
110	case HP_SDC_HIL_TO:
111		mlc->ipacket[idx] |= HIL_ERR_INT | HIL_ERR_LERR;
112		break;
113	case HP_SDC_HIL_RC:
114		printk(KERN_WARNING PREFIX "Bastard SDC decided to reconfigure loop!\n");
115		break;
116	default:
117		printk(KERN_WARNING PREFIX "Unkown HIL Error status (%x)!\n", data);
118		break;
119	}
120	/* No more data will be coming due to an error. */
121 done:
122	tasklet_schedule(mlc->tasklet);
123	up(&(mlc->isem));
124 out:
125	write_unlock(&(mlc->lock));
126}
127
128
129/******************** Tasklet or userspace context functions ****************/
130
131static int hp_sdc_mlc_in (hil_mlc *mlc, suseconds_t timeout) {
132	unsigned long flags;
133	struct hp_sdc_mlc_priv_s *priv;
134	int rc = 2;
135
136	priv = mlc->priv;
137
138	write_lock_irqsave(&(mlc->lock), flags);
139
140	/* Try to down the semaphore */
141	if (down_trylock(&(mlc->isem))) {
142		struct timeval tv;
143		if (priv->emtestmode) {
144			mlc->ipacket[0] =
145				HIL_ERR_INT | (mlc->opacket &
146					       (HIL_PKT_CMD |
147						HIL_PKT_ADDR_MASK |
148						HIL_PKT_DATA_MASK));
149			mlc->icount = 14;
150			/* printk(KERN_DEBUG PREFIX ">[%x]\n", mlc->ipacket[0]); */
151			goto wasup;
152		}
153		do_gettimeofday(&tv);
154		tv.tv_usec += 1000000 * (tv.tv_sec - mlc->instart.tv_sec);
155		if (tv.tv_usec - mlc->instart.tv_usec > mlc->intimeout) {
156		  /*		  printk("!%i %i",
157				  tv.tv_usec - mlc->instart.tv_usec,
158				  mlc->intimeout);
159		  */
160			rc = 1;
161			up(&(mlc->isem));
162		}
163		goto done;
164	}
165 wasup:
166	up(&(mlc->isem));
167	rc = 0;
168	goto done;
169 done:
170	write_unlock_irqrestore(&(mlc->lock), flags);
171	return rc;
172}
173
174static int hp_sdc_mlc_cts (hil_mlc *mlc) {
175	struct hp_sdc_mlc_priv_s *priv;
176	unsigned long flags;
177
178	priv = mlc->priv;
179
180	write_lock_irqsave(&(mlc->lock), flags);
181
182	/* Try to down the semaphores -- they should be up. */
183	if (down_trylock(&(mlc->isem))) {
184		BUG();
185		goto busy;
186	}
187	if (down_trylock(&(mlc->osem))) {
188	 	BUG();
189		up(&(mlc->isem));
190		goto busy;
191	}
192	up(&(mlc->isem));
193	up(&(mlc->osem));
194
195	if (down_trylock(&(mlc->csem))) {
196		if (priv->trans.act.semaphore != &(mlc->csem)) goto poll;
197		goto busy;
198	}
199	if (!(priv->tseq[4] & HP_SDC_USE_LOOP)) goto done;
200
201 poll:
202	priv->trans.act.semaphore = &(mlc->csem);
203	priv->trans.actidx = 0;
204	priv->trans.idx = 1;
205	priv->trans.endidx = 5;
206	priv->tseq[0] =
207		HP_SDC_ACT_POSTCMD | HP_SDC_ACT_DATAIN | HP_SDC_ACT_SEMAPHORE;
208	priv->tseq[1] = HP_SDC_CMD_READ_USE;
209	priv->tseq[2] = 1;
210	priv->tseq[3] = 0;
211	priv->tseq[4] = 0;
212	hp_sdc_enqueue_transaction(&(priv->trans));
213 busy:
214	write_unlock_irqrestore(&(mlc->lock), flags);
215	return 1;
216 done:
217	priv->trans.act.semaphore = &(mlc->osem);
218	up(&(mlc->csem));
219	write_unlock_irqrestore(&(mlc->lock), flags);
220	return 0;
221}
222
223static void hp_sdc_mlc_out (hil_mlc *mlc) {
224	struct hp_sdc_mlc_priv_s *priv;
225	unsigned long flags;
226
227	priv = mlc->priv;
228
229	write_lock_irqsave(&(mlc->lock), flags);
230
231	/* Try to down the semaphore -- it should be up. */
232	if (down_trylock(&(mlc->osem))) {
233	 	BUG();
234		goto done;
235	}
236
237	if (mlc->opacket & HIL_DO_ALTER_CTRL) goto do_control;
238
239 do_data:
240	if (priv->emtestmode) {
241		up(&(mlc->osem));
242		goto done;
243	}
244	/* Shouldn't be sending commands when loop may be busy */
245	if (down_trylock(&(mlc->csem))) {
246	 	BUG();
247		goto done;
248	}
249	up(&(mlc->csem));
250
251	priv->trans.actidx = 0;
252	priv->trans.idx = 1;
253	priv->trans.act.semaphore = &(mlc->osem);
254	priv->trans.endidx = 6;
255	priv->tseq[0] =
256		HP_SDC_ACT_DATAREG | HP_SDC_ACT_POSTCMD | HP_SDC_ACT_SEMAPHORE;
257	priv->tseq[1] = 0x7;
258	priv->tseq[2] =
259		(mlc->opacket &
260		 (HIL_PKT_ADDR_MASK | HIL_PKT_CMD))
261		   >> HIL_PKT_ADDR_SHIFT;
262	priv->tseq[3] =
263		(mlc->opacket & HIL_PKT_DATA_MASK)
264		  >> HIL_PKT_DATA_SHIFT;
265	priv->tseq[4] = 0;  /* No timeout */
266	if (priv->tseq[3] == HIL_CMD_DHR) priv->tseq[4] = 1;
267	priv->tseq[5] = HP_SDC_CMD_DO_HIL;
268	goto enqueue;
269
270 do_control:
271	priv->emtestmode = mlc->opacket & HIL_CTRL_TEST;
272	if ((mlc->opacket & (HIL_CTRL_APE | HIL_CTRL_IPF)) == HIL_CTRL_APE) {
273		BUG(); /* we cannot emulate this, it should not be used. */
274	}
275	if ((mlc->opacket & HIL_CTRL_ONLY) == HIL_CTRL_ONLY) goto control_only;
276	if (mlc->opacket & HIL_CTRL_APE) {
277		BUG(); /* Should not send command/data after engaging APE */
278		goto done;
279	}
280	/* Disengaging APE this way would not be valid either since
281	 * the loop must be allowed to idle.
282	 *
283	 * So, it works out that we really never actually send control
284	 * and data when using SDC, we just send the data.
285	 */
286	goto do_data;
287
288 control_only:
289	priv->trans.actidx = 0;
290	priv->trans.idx = 1;
291	priv->trans.act.semaphore = &(mlc->osem);
292	priv->trans.endidx = 4;
293	priv->tseq[0] =
294	  HP_SDC_ACT_PRECMD | HP_SDC_ACT_DATAOUT | HP_SDC_ACT_SEMAPHORE;
295	priv->tseq[1] = HP_SDC_CMD_SET_LPC;
296	priv->tseq[2] = 1;
297	//	priv->tseq[3] = (mlc->ddc + 1) | HP_SDC_LPS_ACSUCC;
298	priv->tseq[3] = 0;
299	if (mlc->opacket & HIL_CTRL_APE) {
300		priv->tseq[3] |= HP_SDC_LPC_APE_IPF;
301		down_trylock(&(mlc->csem));
302	}
303 enqueue:
304	hp_sdc_enqueue_transaction(&(priv->trans));
305 done:
306	write_unlock_irqrestore(&(mlc->lock), flags);
307}
308
309
310static void hp_sdc_mlc_inc_use_count (void) {
311	MOD_INC_USE_COUNT;
312}
313
314static void hp_sdc_mlc_dec_use_count (void) {
315	MOD_DEC_USE_COUNT;
316}
317
318static int __init hp_sdc_mlc_init(void)
319{
320	hil_mlc *mlc = &hp_sdc_mlc;
321
322	printk(KERN_INFO PREFIX "Registering the System Domain Controller's HIL MLC.\n");
323
324	hp_sdc_mlc_priv.emtestmode = 0;
325	hp_sdc_mlc_priv.trans.seq = hp_sdc_mlc_priv.tseq;
326	hp_sdc_mlc_priv.trans.act.semaphore = &(mlc->osem);
327	hp_sdc_mlc_priv.got5x = 0;
328
329	mlc->cts		= &hp_sdc_mlc_cts;
330	mlc->in			= &hp_sdc_mlc_in;
331	mlc->out		= &hp_sdc_mlc_out;
332
333	mlc->inc_use_count 	= &hp_sdc_mlc_inc_use_count;
334	mlc->dec_use_count 	= &hp_sdc_mlc_dec_use_count;
335
336	if (hil_mlc_register(mlc)) {
337		printk(KERN_WARNING PREFIX "Failed to register MLC structure with hil_mlc\n");
338		goto err0;
339	}
340	mlc->priv		= &hp_sdc_mlc_priv;
341
342	if (hp_sdc_request_hil_irq(&hp_sdc_mlc_isr)) {
343		printk(KERN_WARNING PREFIX "Request for raw HIL ISR hook denied\n");
344		goto err1;
345	}
346	return 0;
347 err1:
348	if (hil_mlc_unregister(mlc)) {
349		printk(KERN_ERR PREFIX "Failed to unregister MLC structure with hil_mlc.\n"
350			"This is bad.  Could cause an oops.\n");
351	}
352 err0:
353	return -EBUSY;
354}
355
356static void __exit hp_sdc_mlc_exit(void)
357{
358	hil_mlc *mlc = &hp_sdc_mlc;
359	if (hp_sdc_release_hil_irq(&hp_sdc_mlc_isr)) {
360		printk(KERN_ERR PREFIX "Failed to release the raw HIL ISR hook.\n"
361			"This is bad.  Could cause an oops.\n");
362	}
363	if (hil_mlc_unregister(mlc)) {
364		printk(KERN_ERR PREFIX "Failed to unregister MLC structure with hil_mlc.\n"
365			"This is bad.  Could cause an oops.\n");
366	}
367}
368
369module_init(hp_sdc_mlc_init);
370module_exit(hp_sdc_mlc_exit);
371