xref: /openbmc/linux/drivers/parport/parport_gsc.c (revision 8dde5715)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *      Low-level parallel-support for PC-style hardware integrated in the
4  *	LASI-Controller (on GSC-Bus) for HP-PARISC Workstations
5  *
6  *	(C) 1999-2001 by Helge Deller <deller@gmx.de>
7  *
8  * based on parport_pc.c by
9  * 	    Grant Guenther <grant@torque.net>
10  * 	    Phil Blundell <philb@gnu.org>
11  *          Tim Waugh <tim@cyberelk.demon.co.uk>
12  *	    Jose Renau <renau@acm.org>
13  *          David Campbell
14  *          Andrea Arcangeli
15  */
16 
17 #undef DEBUG	/* undef for production */
18 
19 #include <linux/module.h>
20 #include <linux/init.h>
21 #include <linux/delay.h>
22 #include <linux/errno.h>
23 #include <linux/interrupt.h>
24 #include <linux/ioport.h>
25 #include <linux/kernel.h>
26 #include <linux/slab.h>
27 #include <linux/pci.h>
28 #include <linux/sysctl.h>
29 
30 #include <asm/io.h>
31 #include <asm/dma.h>
32 #include <linux/uaccess.h>
33 #include <asm/superio.h>
34 
35 #include <linux/parport.h>
36 #include <asm/pdc.h>
37 #include <asm/parisc-device.h>
38 #include <asm/hardware.h>
39 #include "parport_gsc.h"
40 
41 
42 MODULE_AUTHOR("Helge Deller <deller@gmx.de>");
43 MODULE_DESCRIPTION("HP-PARISC PC-style parallel port driver");
44 MODULE_SUPPORTED_DEVICE("integrated PC-style parallel port");
45 MODULE_LICENSE("GPL");
46 
47 
48 /*
49  * Clear TIMEOUT BIT in EPP MODE
50  *
51  * This is also used in SPP detection.
52  */
53 static int clear_epp_timeout(struct parport *pb)
54 {
55 	unsigned char r;
56 
57 	if (!(parport_gsc_read_status(pb) & 0x01))
58 		return 1;
59 
60 	/* To clear timeout some chips require double read */
61 	parport_gsc_read_status(pb);
62 	r = parport_gsc_read_status(pb);
63 	parport_writeb (r | 0x01, STATUS (pb)); /* Some reset by writing 1 */
64 	parport_writeb (r & 0xfe, STATUS (pb)); /* Others by writing 0 */
65 	r = parport_gsc_read_status(pb);
66 
67 	return !(r & 0x01);
68 }
69 
70 /*
71  * Access functions.
72  *
73  * Most of these aren't static because they may be used by the
74  * parport_xxx_yyy macros.  extern __inline__ versions of several
75  * of these are in parport_gsc.h.
76  */
77 
78 void parport_gsc_init_state(struct pardevice *dev, struct parport_state *s)
79 {
80 	s->u.pc.ctr = 0xc | (dev->irq_func ? 0x10 : 0x0);
81 }
82 
83 void parport_gsc_save_state(struct parport *p, struct parport_state *s)
84 {
85 	s->u.pc.ctr = parport_readb (CONTROL (p));
86 }
87 
88 void parport_gsc_restore_state(struct parport *p, struct parport_state *s)
89 {
90 	parport_writeb (s->u.pc.ctr, CONTROL (p));
91 }
92 
93 struct parport_operations parport_gsc_ops =
94 {
95 	.write_data	= parport_gsc_write_data,
96 	.read_data	= parport_gsc_read_data,
97 
98 	.write_control	= parport_gsc_write_control,
99 	.read_control	= parport_gsc_read_control,
100 	.frob_control	= parport_gsc_frob_control,
101 
102 	.read_status	= parport_gsc_read_status,
103 
104 	.enable_irq	= parport_gsc_enable_irq,
105 	.disable_irq	= parport_gsc_disable_irq,
106 
107 	.data_forward	= parport_gsc_data_forward,
108 	.data_reverse	= parport_gsc_data_reverse,
109 
110 	.init_state	= parport_gsc_init_state,
111 	.save_state	= parport_gsc_save_state,
112 	.restore_state	= parport_gsc_restore_state,
113 
114 	.epp_write_data	= parport_ieee1284_epp_write_data,
115 	.epp_read_data	= parport_ieee1284_epp_read_data,
116 	.epp_write_addr	= parport_ieee1284_epp_write_addr,
117 	.epp_read_addr	= parport_ieee1284_epp_read_addr,
118 
119 	.ecp_write_data	= parport_ieee1284_ecp_write_data,
120 	.ecp_read_data	= parport_ieee1284_ecp_read_data,
121 	.ecp_write_addr	= parport_ieee1284_ecp_write_addr,
122 
123 	.compat_write_data 	= parport_ieee1284_write_compat,
124 	.nibble_read_data	= parport_ieee1284_read_nibble,
125 	.byte_read_data		= parport_ieee1284_read_byte,
126 
127 	.owner		= THIS_MODULE,
128 };
129 
130 /* --- Mode detection ------------------------------------- */
131 
132 /*
133  * Checks for port existence, all ports support SPP MODE
134  */
135 static int parport_SPP_supported(struct parport *pb)
136 {
137 	unsigned char r, w;
138 
139 	/*
140 	 * first clear an eventually pending EPP timeout
141 	 * I (sailer@ife.ee.ethz.ch) have an SMSC chipset
142 	 * that does not even respond to SPP cycles if an EPP
143 	 * timeout is pending
144 	 */
145 	clear_epp_timeout(pb);
146 
147 	/* Do a simple read-write test to make sure the port exists. */
148 	w = 0xc;
149 	parport_writeb (w, CONTROL (pb));
150 
151 	/* Is there a control register that we can read from?  Some
152 	 * ports don't allow reads, so read_control just returns a
153 	 * software copy. Some ports _do_ allow reads, so bypass the
154 	 * software copy here.  In addition, some bits aren't
155 	 * writable. */
156 	r = parport_readb (CONTROL (pb));
157 	if ((r & 0xf) == w) {
158 		w = 0xe;
159 		parport_writeb (w, CONTROL (pb));
160 		r = parport_readb (CONTROL (pb));
161 		parport_writeb (0xc, CONTROL (pb));
162 		if ((r & 0xf) == w)
163 			return PARPORT_MODE_PCSPP;
164 	}
165 
166 	/* Try the data register.  The data lines aren't tri-stated at
167 	 * this stage, so we expect back what we wrote. */
168 	w = 0xaa;
169 	parport_gsc_write_data (pb, w);
170 	r = parport_gsc_read_data (pb);
171 	if (r == w) {
172 		w = 0x55;
173 		parport_gsc_write_data (pb, w);
174 		r = parport_gsc_read_data (pb);
175 		if (r == w)
176 			return PARPORT_MODE_PCSPP;
177 	}
178 
179 	return 0;
180 }
181 
182 /* Detect PS/2 support.
183  *
184  * Bit 5 (0x20) sets the PS/2 data direction; setting this high
185  * allows us to read data from the data lines.  In theory we would get back
186  * 0xff but any peripheral attached to the port may drag some or all of the
187  * lines down to zero.  So if we get back anything that isn't the contents
188  * of the data register we deem PS/2 support to be present.
189  *
190  * Some SPP ports have "half PS/2" ability - you can't turn off the line
191  * drivers, but an external peripheral with sufficiently beefy drivers of
192  * its own can overpower them and assert its own levels onto the bus, from
193  * where they can then be read back as normal.  Ports with this property
194  * and the right type of device attached are likely to fail the SPP test,
195  * (as they will appear to have stuck bits) and so the fact that they might
196  * be misdetected here is rather academic.
197  */
198 
199 static int parport_PS2_supported(struct parport *pb)
200 {
201 	int ok = 0;
202 
203 	clear_epp_timeout(pb);
204 
205 	/* try to tri-state the buffer */
206 	parport_gsc_data_reverse (pb);
207 
208 	parport_gsc_write_data(pb, 0x55);
209 	if (parport_gsc_read_data(pb) != 0x55) ok++;
210 
211 	parport_gsc_write_data(pb, 0xaa);
212 	if (parport_gsc_read_data(pb) != 0xaa) ok++;
213 
214 	/* cancel input mode */
215 	parport_gsc_data_forward (pb);
216 
217 	if (ok) {
218 		pb->modes |= PARPORT_MODE_TRISTATE;
219 	} else {
220 		struct parport_gsc_private *priv = pb->private_data;
221 		priv->ctr_writable &= ~0x20;
222 	}
223 
224 	return ok;
225 }
226 
227 
228 /* --- Initialisation code -------------------------------- */
229 
230 struct parport *parport_gsc_probe_port(unsigned long base,
231 				       unsigned long base_hi, int irq,
232 				       int dma, struct parisc_device *padev)
233 {
234 	struct parport_gsc_private *priv;
235 	struct parport_operations *ops;
236 	struct parport tmp;
237 	struct parport *p = &tmp;
238 
239 	priv = kzalloc (sizeof (struct parport_gsc_private), GFP_KERNEL);
240 	if (!priv) {
241 		printk (KERN_DEBUG "parport (0x%lx): no memory!\n", base);
242 		return NULL;
243 	}
244 	ops = kmemdup(&parport_gsc_ops, sizeof(struct parport_operations),
245 		      GFP_KERNEL);
246 	if (!ops) {
247 		printk (KERN_DEBUG "parport (0x%lx): no memory for ops!\n",
248 			base);
249 		kfree (priv);
250 		return NULL;
251 	}
252 	priv->ctr = 0xc;
253 	priv->ctr_writable = 0xff;
254 	priv->dma_buf = NULL;
255 	priv->dma_handle = 0;
256 	p->base = base;
257 	p->base_hi = base_hi;
258 	p->irq = irq;
259 	p->dma = dma;
260 	p->modes = PARPORT_MODE_PCSPP | PARPORT_MODE_SAFEININT;
261 	p->ops = ops;
262 	p->private_data = priv;
263 	p->physport = p;
264 	if (!parport_SPP_supported (p)) {
265 		/* No port. */
266 		kfree (priv);
267 		kfree(ops);
268 		return NULL;
269 	}
270 	parport_PS2_supported (p);
271 
272 	if (!(p = parport_register_port(base, PARPORT_IRQ_NONE,
273 					PARPORT_DMA_NONE, ops))) {
274 		kfree (priv);
275 		kfree (ops);
276 		return NULL;
277 	}
278 
279 	p->dev = &padev->dev;
280 	p->base_hi = base_hi;
281 	p->modes = tmp.modes;
282 	p->size = (p->modes & PARPORT_MODE_EPP)?8:3;
283 	p->private_data = priv;
284 
285 	printk(KERN_INFO "%s: PC-style at 0x%lx", p->name, p->base);
286 	p->irq = irq;
287 	if (p->irq == PARPORT_IRQ_AUTO) {
288 		p->irq = PARPORT_IRQ_NONE;
289 	}
290 	if (p->irq != PARPORT_IRQ_NONE) {
291 		pr_cont(", irq %d", p->irq);
292 
293 		if (p->dma == PARPORT_DMA_AUTO) {
294 			p->dma = PARPORT_DMA_NONE;
295 		}
296 	}
297 	if (p->dma == PARPORT_DMA_AUTO) /* To use DMA, giving the irq
298                                            is mandatory (see above) */
299 		p->dma = PARPORT_DMA_NONE;
300 
301 	pr_cont(" [");
302 #define printmode(x) {if(p->modes&PARPORT_MODE_##x){pr_cont("%s%s",f?",":"",#x);f++;}}
303 	{
304 		int f = 0;
305 		printmode(PCSPP);
306 		printmode(TRISTATE);
307 		printmode(COMPAT)
308 		printmode(EPP);
309 //		printmode(ECP);
310 //		printmode(DMA);
311 	}
312 #undef printmode
313 	pr_cont("]\n");
314 
315 	if (p->irq != PARPORT_IRQ_NONE) {
316 		if (request_irq (p->irq, parport_irq_handler,
317 				 0, p->name, p)) {
318 			printk (KERN_WARNING "%s: irq %d in use, "
319 				"resorting to polled operation\n",
320 				p->name, p->irq);
321 			p->irq = PARPORT_IRQ_NONE;
322 			p->dma = PARPORT_DMA_NONE;
323 		}
324 	}
325 
326 	/* Done probing.  Now put the port into a sensible start-up state. */
327 
328 	parport_gsc_write_data(p, 0);
329 	parport_gsc_data_forward (p);
330 
331 	/* Now that we've told the sharing engine about the port, and
332 	   found out its characteristics, let the high-level drivers
333 	   know about it. */
334 	parport_announce_port (p);
335 
336 	return p;
337 }
338 
339 
340 #define PARPORT_GSC_OFFSET 0x800
341 
342 static int parport_count;
343 
344 static int __init parport_init_chip(struct parisc_device *dev)
345 {
346 	struct parport *p;
347 	unsigned long port;
348 
349 	if (!dev->irq) {
350 		printk(KERN_WARNING "IRQ not found for parallel device at 0x%llx\n",
351 			(unsigned long long)dev->hpa.start);
352 		return -ENODEV;
353 	}
354 
355 	port = dev->hpa.start + PARPORT_GSC_OFFSET;
356 
357 	/* some older machines with ASP-chip don't support
358 	 * the enhanced parport modes.
359 	 */
360 	if (boot_cpu_data.cpu_type > pcxt && !pdc_add_valid(port+4)) {
361 
362 		/* Initialize bidirectional-mode (0x10) & data-tranfer-mode #1 (0x20) */
363 		printk("%s: initialize bidirectional-mode.\n", __func__);
364 		parport_writeb ( (0x10 + 0x20), port + 4);
365 
366 	} else {
367 		printk("%s: enhanced parport-modes not supported.\n", __func__);
368 	}
369 
370 	p = parport_gsc_probe_port(port, 0, dev->irq,
371 			/* PARPORT_IRQ_NONE */ PARPORT_DMA_NONE, dev);
372 	if (p)
373 		parport_count++;
374 	dev_set_drvdata(&dev->dev, p);
375 
376 	return 0;
377 }
378 
379 static int __exit parport_remove_chip(struct parisc_device *dev)
380 {
381 	struct parport *p = dev_get_drvdata(&dev->dev);
382 	if (p) {
383 		struct parport_gsc_private *priv = p->private_data;
384 		struct parport_operations *ops = p->ops;
385 		parport_remove_port(p);
386 		if (p->dma != PARPORT_DMA_NONE)
387 			free_dma(p->dma);
388 		if (p->irq != PARPORT_IRQ_NONE)
389 			free_irq(p->irq, p);
390 		if (priv->dma_buf)
391 			pci_free_consistent(priv->dev, PAGE_SIZE,
392 					    priv->dma_buf,
393 					    priv->dma_handle);
394 		kfree (p->private_data);
395 		parport_put_port(p);
396 		kfree (ops); /* hope no-one cached it */
397 	}
398 	return 0;
399 }
400 
401 static const struct parisc_device_id parport_tbl[] __initconst = {
402 	{ HPHW_FIO, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x74 },
403 	{ 0, }
404 };
405 
406 MODULE_DEVICE_TABLE(parisc, parport_tbl);
407 
408 static struct parisc_driver parport_driver __refdata = {
409 	.name		= "Parallel",
410 	.id_table	= parport_tbl,
411 	.probe		= parport_init_chip,
412 	.remove		= __exit_p(parport_remove_chip),
413 };
414 
415 int parport_gsc_init(void)
416 {
417 	return register_parisc_driver(&parport_driver);
418 }
419 
420 static void parport_gsc_exit(void)
421 {
422 	unregister_parisc_driver(&parport_driver);
423 }
424 
425 module_init(parport_gsc_init);
426 module_exit(parport_gsc_exit);
427