xref: /openbmc/linux/drivers/parport/parport_gsc.c (revision 0c874100)
1 /*
2  *      Low-level parallel-support for PC-style hardware integrated in the
3  *	LASI-Controller (on GSC-Bus) for HP-PARISC Workstations
4  *
5  *	This program is free software; you can redistribute it and/or modify
6  *	it under the terms of the GNU General Public License as published by
7  *      the Free Software Foundation; either version 2 of the License, or
8  *      (at your option) any later version.
9  *
10  *	(C) 1999-2001 by Helge Deller <deller@gmx.de>
11  *
12  *
13  * based on parport_pc.c by
14  * 	    Grant Guenther <grant@torque.net>
15  * 	    Phil Blundell <philb@gnu.org>
16  *          Tim Waugh <tim@cyberelk.demon.co.uk>
17  *	    Jose Renau <renau@acm.org>
18  *          David Campbell
19  *          Andrea Arcangeli
20  */
21 
22 #undef DEBUG	/* undef for production */
23 
24 #include <linux/module.h>
25 #include <linux/init.h>
26 #include <linux/delay.h>
27 #include <linux/errno.h>
28 #include <linux/interrupt.h>
29 #include <linux/ioport.h>
30 #include <linux/kernel.h>
31 #include <linux/slab.h>
32 #include <linux/pci.h>
33 #include <linux/sysctl.h>
34 
35 #include <asm/io.h>
36 #include <asm/dma.h>
37 #include <linux/uaccess.h>
38 #include <asm/superio.h>
39 
40 #include <linux/parport.h>
41 #include <asm/pdc.h>
42 #include <asm/parisc-device.h>
43 #include <asm/hardware.h>
44 #include "parport_gsc.h"
45 
46 
47 MODULE_AUTHOR("Helge Deller <deller@gmx.de>");
48 MODULE_DESCRIPTION("HP-PARISC PC-style parallel port driver");
49 MODULE_SUPPORTED_DEVICE("integrated PC-style parallel port");
50 MODULE_LICENSE("GPL");
51 
52 
53 /*
54  * Clear TIMEOUT BIT in EPP MODE
55  *
56  * This is also used in SPP detection.
57  */
58 static int clear_epp_timeout(struct parport *pb)
59 {
60 	unsigned char r;
61 
62 	if (!(parport_gsc_read_status(pb) & 0x01))
63 		return 1;
64 
65 	/* To clear timeout some chips require double read */
66 	parport_gsc_read_status(pb);
67 	r = parport_gsc_read_status(pb);
68 	parport_writeb (r | 0x01, STATUS (pb)); /* Some reset by writing 1 */
69 	parport_writeb (r & 0xfe, STATUS (pb)); /* Others by writing 0 */
70 	r = parport_gsc_read_status(pb);
71 
72 	return !(r & 0x01);
73 }
74 
75 /*
76  * Access functions.
77  *
78  * Most of these aren't static because they may be used by the
79  * parport_xxx_yyy macros.  extern __inline__ versions of several
80  * of these are in parport_gsc.h.
81  */
82 
83 void parport_gsc_init_state(struct pardevice *dev, struct parport_state *s)
84 {
85 	s->u.pc.ctr = 0xc | (dev->irq_func ? 0x10 : 0x0);
86 }
87 
88 void parport_gsc_save_state(struct parport *p, struct parport_state *s)
89 {
90 	s->u.pc.ctr = parport_readb (CONTROL (p));
91 }
92 
93 void parport_gsc_restore_state(struct parport *p, struct parport_state *s)
94 {
95 	parport_writeb (s->u.pc.ctr, CONTROL (p));
96 }
97 
98 struct parport_operations parport_gsc_ops =
99 {
100 	.write_data	= parport_gsc_write_data,
101 	.read_data	= parport_gsc_read_data,
102 
103 	.write_control	= parport_gsc_write_control,
104 	.read_control	= parport_gsc_read_control,
105 	.frob_control	= parport_gsc_frob_control,
106 
107 	.read_status	= parport_gsc_read_status,
108 
109 	.enable_irq	= parport_gsc_enable_irq,
110 	.disable_irq	= parport_gsc_disable_irq,
111 
112 	.data_forward	= parport_gsc_data_forward,
113 	.data_reverse	= parport_gsc_data_reverse,
114 
115 	.init_state	= parport_gsc_init_state,
116 	.save_state	= parport_gsc_save_state,
117 	.restore_state	= parport_gsc_restore_state,
118 
119 	.epp_write_data	= parport_ieee1284_epp_write_data,
120 	.epp_read_data	= parport_ieee1284_epp_read_data,
121 	.epp_write_addr	= parport_ieee1284_epp_write_addr,
122 	.epp_read_addr	= parport_ieee1284_epp_read_addr,
123 
124 	.ecp_write_data	= parport_ieee1284_ecp_write_data,
125 	.ecp_read_data	= parport_ieee1284_ecp_read_data,
126 	.ecp_write_addr	= parport_ieee1284_ecp_write_addr,
127 
128 	.compat_write_data 	= parport_ieee1284_write_compat,
129 	.nibble_read_data	= parport_ieee1284_read_nibble,
130 	.byte_read_data		= parport_ieee1284_read_byte,
131 
132 	.owner		= THIS_MODULE,
133 };
134 
135 /* --- Mode detection ------------------------------------- */
136 
137 /*
138  * Checks for port existence, all ports support SPP MODE
139  */
140 static int parport_SPP_supported(struct parport *pb)
141 {
142 	unsigned char r, w;
143 
144 	/*
145 	 * first clear an eventually pending EPP timeout
146 	 * I (sailer@ife.ee.ethz.ch) have an SMSC chipset
147 	 * that does not even respond to SPP cycles if an EPP
148 	 * timeout is pending
149 	 */
150 	clear_epp_timeout(pb);
151 
152 	/* Do a simple read-write test to make sure the port exists. */
153 	w = 0xc;
154 	parport_writeb (w, CONTROL (pb));
155 
156 	/* Is there a control register that we can read from?  Some
157 	 * ports don't allow reads, so read_control just returns a
158 	 * software copy. Some ports _do_ allow reads, so bypass the
159 	 * software copy here.  In addition, some bits aren't
160 	 * writable. */
161 	r = parport_readb (CONTROL (pb));
162 	if ((r & 0xf) == w) {
163 		w = 0xe;
164 		parport_writeb (w, CONTROL (pb));
165 		r = parport_readb (CONTROL (pb));
166 		parport_writeb (0xc, CONTROL (pb));
167 		if ((r & 0xf) == w)
168 			return PARPORT_MODE_PCSPP;
169 	}
170 
171 	/* Try the data register.  The data lines aren't tri-stated at
172 	 * this stage, so we expect back what we wrote. */
173 	w = 0xaa;
174 	parport_gsc_write_data (pb, w);
175 	r = parport_gsc_read_data (pb);
176 	if (r == w) {
177 		w = 0x55;
178 		parport_gsc_write_data (pb, w);
179 		r = parport_gsc_read_data (pb);
180 		if (r == w)
181 			return PARPORT_MODE_PCSPP;
182 	}
183 
184 	return 0;
185 }
186 
187 /* Detect PS/2 support.
188  *
189  * Bit 5 (0x20) sets the PS/2 data direction; setting this high
190  * allows us to read data from the data lines.  In theory we would get back
191  * 0xff but any peripheral attached to the port may drag some or all of the
192  * lines down to zero.  So if we get back anything that isn't the contents
193  * of the data register we deem PS/2 support to be present.
194  *
195  * Some SPP ports have "half PS/2" ability - you can't turn off the line
196  * drivers, but an external peripheral with sufficiently beefy drivers of
197  * its own can overpower them and assert its own levels onto the bus, from
198  * where they can then be read back as normal.  Ports with this property
199  * and the right type of device attached are likely to fail the SPP test,
200  * (as they will appear to have stuck bits) and so the fact that they might
201  * be misdetected here is rather academic.
202  */
203 
204 static int parport_PS2_supported(struct parport *pb)
205 {
206 	int ok = 0;
207 
208 	clear_epp_timeout(pb);
209 
210 	/* try to tri-state the buffer */
211 	parport_gsc_data_reverse (pb);
212 
213 	parport_gsc_write_data(pb, 0x55);
214 	if (parport_gsc_read_data(pb) != 0x55) ok++;
215 
216 	parport_gsc_write_data(pb, 0xaa);
217 	if (parport_gsc_read_data(pb) != 0xaa) ok++;
218 
219 	/* cancel input mode */
220 	parport_gsc_data_forward (pb);
221 
222 	if (ok) {
223 		pb->modes |= PARPORT_MODE_TRISTATE;
224 	} else {
225 		struct parport_gsc_private *priv = pb->private_data;
226 		priv->ctr_writable &= ~0x20;
227 	}
228 
229 	return ok;
230 }
231 
232 
233 /* --- Initialisation code -------------------------------- */
234 
235 struct parport *parport_gsc_probe_port(unsigned long base,
236 				       unsigned long base_hi, int irq,
237 				       int dma, struct parisc_device *padev)
238 {
239 	struct parport_gsc_private *priv;
240 	struct parport_operations *ops;
241 	struct parport tmp;
242 	struct parport *p = &tmp;
243 
244 	priv = kzalloc (sizeof (struct parport_gsc_private), GFP_KERNEL);
245 	if (!priv) {
246 		printk (KERN_DEBUG "parport (0x%lx): no memory!\n", base);
247 		return NULL;
248 	}
249 	ops = kmemdup(&parport_gsc_ops, sizeof(struct parport_operations),
250 		      GFP_KERNEL);
251 	if (!ops) {
252 		printk (KERN_DEBUG "parport (0x%lx): no memory for ops!\n",
253 			base);
254 		kfree (priv);
255 		return NULL;
256 	}
257 	priv->ctr = 0xc;
258 	priv->ctr_writable = 0xff;
259 	priv->dma_buf = NULL;
260 	priv->dma_handle = 0;
261 	p->base = base;
262 	p->base_hi = base_hi;
263 	p->irq = irq;
264 	p->dma = dma;
265 	p->modes = PARPORT_MODE_PCSPP | PARPORT_MODE_SAFEININT;
266 	p->ops = ops;
267 	p->private_data = priv;
268 	p->physport = p;
269 	if (!parport_SPP_supported (p)) {
270 		/* No port. */
271 		kfree (priv);
272 		kfree(ops);
273 		return NULL;
274 	}
275 	parport_PS2_supported (p);
276 
277 	if (!(p = parport_register_port(base, PARPORT_IRQ_NONE,
278 					PARPORT_DMA_NONE, ops))) {
279 		kfree (priv);
280 		kfree (ops);
281 		return NULL;
282 	}
283 
284 	p->dev = &padev->dev;
285 	p->base_hi = base_hi;
286 	p->modes = tmp.modes;
287 	p->size = (p->modes & PARPORT_MODE_EPP)?8:3;
288 	p->private_data = priv;
289 
290 	printk(KERN_INFO "%s: PC-style at 0x%lx", p->name, p->base);
291 	p->irq = irq;
292 	if (p->irq == PARPORT_IRQ_AUTO) {
293 		p->irq = PARPORT_IRQ_NONE;
294 	}
295 	if (p->irq != PARPORT_IRQ_NONE) {
296 		pr_cont(", irq %d", p->irq);
297 
298 		if (p->dma == PARPORT_DMA_AUTO) {
299 			p->dma = PARPORT_DMA_NONE;
300 		}
301 	}
302 	if (p->dma == PARPORT_DMA_AUTO) /* To use DMA, giving the irq
303                                            is mandatory (see above) */
304 		p->dma = PARPORT_DMA_NONE;
305 
306 	pr_cont(" [");
307 #define printmode(x) {if(p->modes&PARPORT_MODE_##x){pr_cont("%s%s",f?",":"",#x);f++;}}
308 	{
309 		int f = 0;
310 		printmode(PCSPP);
311 		printmode(TRISTATE);
312 		printmode(COMPAT)
313 		printmode(EPP);
314 //		printmode(ECP);
315 //		printmode(DMA);
316 	}
317 #undef printmode
318 	pr_cont("]\n");
319 
320 	if (p->irq != PARPORT_IRQ_NONE) {
321 		if (request_irq (p->irq, parport_irq_handler,
322 				 0, p->name, p)) {
323 			printk (KERN_WARNING "%s: irq %d in use, "
324 				"resorting to polled operation\n",
325 				p->name, p->irq);
326 			p->irq = PARPORT_IRQ_NONE;
327 			p->dma = PARPORT_DMA_NONE;
328 		}
329 	}
330 
331 	/* Done probing.  Now put the port into a sensible start-up state. */
332 
333 	parport_gsc_write_data(p, 0);
334 	parport_gsc_data_forward (p);
335 
336 	/* Now that we've told the sharing engine about the port, and
337 	   found out its characteristics, let the high-level drivers
338 	   know about it. */
339 	parport_announce_port (p);
340 
341 	return p;
342 }
343 
344 
345 #define PARPORT_GSC_OFFSET 0x800
346 
347 static int parport_count;
348 
349 static int __init parport_init_chip(struct parisc_device *dev)
350 {
351 	struct parport *p;
352 	unsigned long port;
353 
354 	if (!dev->irq) {
355 		printk(KERN_WARNING "IRQ not found for parallel device at 0x%llx\n",
356 			(unsigned long long)dev->hpa.start);
357 		return -ENODEV;
358 	}
359 
360 	port = dev->hpa.start + PARPORT_GSC_OFFSET;
361 
362 	/* some older machines with ASP-chip don't support
363 	 * the enhanced parport modes.
364 	 */
365 	if (boot_cpu_data.cpu_type > pcxt && !pdc_add_valid(port+4)) {
366 
367 		/* Initialize bidirectional-mode (0x10) & data-tranfer-mode #1 (0x20) */
368 		printk("%s: initialize bidirectional-mode.\n", __func__);
369 		parport_writeb ( (0x10 + 0x20), port + 4);
370 
371 	} else {
372 		printk("%s: enhanced parport-modes not supported.\n", __func__);
373 	}
374 
375 	p = parport_gsc_probe_port(port, 0, dev->irq,
376 			/* PARPORT_IRQ_NONE */ PARPORT_DMA_NONE, dev);
377 	if (p)
378 		parport_count++;
379 	dev_set_drvdata(&dev->dev, p);
380 
381 	return 0;
382 }
383 
384 static int __exit parport_remove_chip(struct parisc_device *dev)
385 {
386 	struct parport *p = dev_get_drvdata(&dev->dev);
387 	if (p) {
388 		struct parport_gsc_private *priv = p->private_data;
389 		struct parport_operations *ops = p->ops;
390 		parport_remove_port(p);
391 		if (p->dma != PARPORT_DMA_NONE)
392 			free_dma(p->dma);
393 		if (p->irq != PARPORT_IRQ_NONE)
394 			free_irq(p->irq, p);
395 		if (priv->dma_buf)
396 			pci_free_consistent(priv->dev, PAGE_SIZE,
397 					    priv->dma_buf,
398 					    priv->dma_handle);
399 		kfree (p->private_data);
400 		parport_put_port(p);
401 		kfree (ops); /* hope no-one cached it */
402 	}
403 	return 0;
404 }
405 
406 static const struct parisc_device_id parport_tbl[] __initconst = {
407 	{ HPHW_FIO, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x74 },
408 	{ 0, }
409 };
410 
411 MODULE_DEVICE_TABLE(parisc, parport_tbl);
412 
413 static struct parisc_driver parport_driver __refdata = {
414 	.name		= "Parallel",
415 	.id_table	= parport_tbl,
416 	.probe		= parport_init_chip,
417 	.remove		= __exit_p(parport_remove_chip),
418 };
419 
420 int parport_gsc_init(void)
421 {
422 	return register_parisc_driver(&parport_driver);
423 }
424 
425 static void parport_gsc_exit(void)
426 {
427 	unregister_parisc_driver(&parport_driver);
428 }
429 
430 module_init(parport_gsc_init);
431 module_exit(parport_gsc_exit);
432