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