1/* ------------------------------------------------------------------------- */
2/* i2c-elektor.c i2c-hw access for PCF8584 style isa bus adaptes             */
3/* ------------------------------------------------------------------------- */
4/*   Copyright (C) 1995-97 Simon G. Vogl
5                   1998-99 Hans Berglund
6
7    This program is free software; you can redistribute it and/or modify
8    it under the terms of the GNU General Public License as published by
9    the Free Software Foundation; either version 2 of the License, or
10    (at your option) any later version.
11
12    This program is distributed in the hope that it will be useful,
13    but WITHOUT ANY WARRANTY; without even the implied warranty of
14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15    GNU General Public License for more details.			     */
16/* ------------------------------------------------------------------------- */
17
18/* With some changes from Ky��sti M��lkki <kmalkki@cc.hut.fi> and even
19   Frodo Looijaard <frodol@dds.nl> */
20
21/* Partially rewriten by Oleg I. Vdovikin for mmapped support of
22   for Alpha Processor Inc. UP-2000(+) boards */
23
24#include <linux/kernel.h>
25#include <linux/ioport.h>
26#include <linux/module.h>
27#include <linux/delay.h>
28#include <linux/init.h>
29#include <linux/interrupt.h>
30#include <linux/pci.h>
31#include <linux/wait.h>
32
33#include <linux/isa.h>
34#include <linux/i2c.h>
35#include <linux/i2c-algo-pcf.h>
36#include <linux/io.h>
37
38#include <asm/irq.h>
39
40#include "../algos/i2c-algo-pcf.h"
41
42#define DEFAULT_BASE 0x330
43
44static int base;
45static u8 __iomem *base_iomem;
46
47static int irq;
48static int clock  = 0x1c;
49static int own    = 0x55;
50static int mmapped;
51
52/* vdovikin: removed static struct i2c_pcf_isa gpi; code -
53  this module in real supports only one device, due to missing arguments
54  in some functions, called from the algo-pcf module. Sometimes it's
55  need to be rewriten - but for now just remove this for simpler reading */
56
57static wait_queue_head_t pcf_wait;
58static int pcf_pending;
59static spinlock_t lock;
60
61static struct i2c_adapter pcf_isa_ops;
62
63/* ----- local functions ----------------------------------------------	*/
64
65static void pcf_isa_setbyte(void *data, int ctl, int val)
66{
67	u8 __iomem *address = ctl ? (base_iomem + 1) : base_iomem;
68
69	/* enable irq if any specified for serial operation */
70	if (ctl && irq && (val & I2C_PCF_ESO)) {
71		val |= I2C_PCF_ENI;
72	}
73
74	pr_debug("%s: Write %p 0x%02X\n", pcf_isa_ops.name, address, val);
75	iowrite8(val, address);
76#ifdef __alpha__
77	/* API UP2000 needs some hardware fudging to make the write stick */
78	iowrite8(val, address);
79#endif
80}
81
82static int pcf_isa_getbyte(void *data, int ctl)
83{
84	u8 __iomem *address = ctl ? (base_iomem + 1) : base_iomem;
85	int val = ioread8(address);
86
87	pr_debug("%s: Read %p 0x%02X\n", pcf_isa_ops.name, address, val);
88	return (val);
89}
90
91static int pcf_isa_getown(void *data)
92{
93	return (own);
94}
95
96
97static int pcf_isa_getclock(void *data)
98{
99	return (clock);
100}
101
102static void pcf_isa_waitforpin(void *data)
103{
104	DEFINE_WAIT(wait);
105	int timeout = 2;
106	unsigned long flags;
107
108	if (irq > 0) {
109		spin_lock_irqsave(&lock, flags);
110		if (pcf_pending == 0) {
111			spin_unlock_irqrestore(&lock, flags);
112			prepare_to_wait(&pcf_wait, &wait, TASK_INTERRUPTIBLE);
113			if (schedule_timeout(timeout*HZ)) {
114				spin_lock_irqsave(&lock, flags);
115				if (pcf_pending == 1) {
116					pcf_pending = 0;
117				}
118				spin_unlock_irqrestore(&lock, flags);
119			}
120			finish_wait(&pcf_wait, &wait);
121		} else {
122			pcf_pending = 0;
123			spin_unlock_irqrestore(&lock, flags);
124		}
125	} else {
126		udelay(100);
127	}
128}
129
130
131static irqreturn_t pcf_isa_handler(int this_irq, void *dev_id) {
132	spin_lock(&lock);
133	pcf_pending = 1;
134	spin_unlock(&lock);
135	wake_up_interruptible(&pcf_wait);
136	return IRQ_HANDLED;
137}
138
139
140static int pcf_isa_init(void)
141{
142	spin_lock_init(&lock);
143	if (!mmapped) {
144		if (!request_region(base, 2, pcf_isa_ops.name)) {
145			printk(KERN_ERR "%s: requested I/O region (%#x:2) is "
146			       "in use\n", pcf_isa_ops.name, base);
147			return -ENODEV;
148		}
149		base_iomem = ioport_map(base, 2);
150		if (!base_iomem) {
151			printk(KERN_ERR "%s: remap of I/O region %#x failed\n",
152			       pcf_isa_ops.name, base);
153			release_region(base, 2);
154			return -ENODEV;
155		}
156	} else {
157		if (!request_mem_region(base, 2, pcf_isa_ops.name)) {
158			printk(KERN_ERR "%s: requested memory region (%#x:2) "
159			       "is in use\n", pcf_isa_ops.name, base);
160			return -ENODEV;
161		}
162		base_iomem = ioremap(base, 2);
163		if (base_iomem == NULL) {
164			printk(KERN_ERR "%s: remap of memory region %#x "
165			       "failed\n", pcf_isa_ops.name, base);
166			release_mem_region(base, 2);
167			return -ENODEV;
168		}
169	}
170	pr_debug("%s: registers %#x remapped to %p\n", pcf_isa_ops.name, base,
171		 base_iomem);
172
173	if (irq > 0) {
174		if (request_irq(irq, pcf_isa_handler, 0, pcf_isa_ops.name,
175				NULL) < 0) {
176			printk(KERN_ERR "%s: Request irq%d failed\n",
177			       pcf_isa_ops.name, irq);
178			irq = 0;
179		} else
180			enable_irq(irq);
181	}
182	return 0;
183}
184
185/* ------------------------------------------------------------------------
186 * Encapsulate the above functions in the correct operations structure.
187 * This is only done when more than one hardware adapter is supported.
188 */
189static struct i2c_algo_pcf_data pcf_isa_data = {
190	.setpcf	    = pcf_isa_setbyte,
191	.getpcf	    = pcf_isa_getbyte,
192	.getown	    = pcf_isa_getown,
193	.getclock   = pcf_isa_getclock,
194	.waitforpin = pcf_isa_waitforpin,
195};
196
197static struct i2c_adapter pcf_isa_ops = {
198	.owner		= THIS_MODULE,
199	.class		= I2C_CLASS_HWMON | I2C_CLASS_SPD,
200	.algo_data	= &pcf_isa_data,
201	.name		= "i2c-elektor",
202};
203
204static int elektor_match(struct device *dev, unsigned int id)
205{
206#ifdef __alpha__
207	/* check to see we have memory mapped PCF8584 connected to the
208	Cypress cy82c693 PCI-ISA bridge as on UP2000 board */
209	if (base == 0) {
210		struct pci_dev *cy693_dev;
211
212		cy693_dev = pci_get_device(PCI_VENDOR_ID_CONTAQ,
213					   PCI_DEVICE_ID_CONTAQ_82C693, NULL);
214		if (cy693_dev) {
215			unsigned char config;
216			/* yeap, we've found cypress, let's check config */
217			if (!pci_read_config_byte(cy693_dev, 0x47, &config)) {
218
219				dev_dbg(dev, "found cy82c693, config "
220					"register 0x47 = 0x%02x\n", config);
221
222				/* UP2000 board has this register set to 0xe1,
223				   but the most significant bit as seems can be
224				   reset during the proper initialisation
225				   sequence if guys from API decides to do that
226				   (so, we can even enable Tsunami Pchip
227				   window for the upper 1 Gb) */
228
229				/* so just check for ROMCS at 0xe0000,
230				   ROMCS enabled for writes
231				   and external XD Bus buffer in use. */
232				if ((config & 0x7f) == 0x61) {
233					/* seems to be UP2000 like board */
234					base = 0xe0000;
235					mmapped = 1;
236					/* UP2000 drives ISA with
237					   8.25 MHz (PCI/4) clock
238					   (this can be read from cypress) */
239					clock = I2C_PCF_CLK | I2C_PCF_TRNS90;
240					dev_info(dev, "found API UP2000 like "
241						 "board, will probe PCF8584 "
242						 "later\n");
243				}
244			}
245			pci_dev_put(cy693_dev);
246		}
247	}
248#endif
249
250	/* sanity checks for mmapped I/O */
251	if (mmapped && base < 0xc8000) {
252		dev_err(dev, "incorrect base address (%#x) specified "
253		       "for mmapped I/O\n", base);
254		return 0;
255	}
256
257	if (base == 0) {
258		base = DEFAULT_BASE;
259	}
260	return 1;
261}
262
263static int elektor_probe(struct device *dev, unsigned int id)
264{
265	init_waitqueue_head(&pcf_wait);
266	if (pcf_isa_init())
267		return -ENODEV;
268	pcf_isa_ops.dev.parent = dev;
269	if (i2c_pcf_add_bus(&pcf_isa_ops) < 0)
270		goto fail;
271
272	dev_info(dev, "found device at %#x\n", base);
273
274	return 0;
275
276 fail:
277	if (irq > 0) {
278		disable_irq(irq);
279		free_irq(irq, NULL);
280	}
281
282	if (!mmapped) {
283		ioport_unmap(base_iomem);
284		release_region(base, 2);
285	} else {
286		iounmap(base_iomem);
287		release_mem_region(base, 2);
288	}
289	return -ENODEV;
290}
291
292static int elektor_remove(struct device *dev, unsigned int id)
293{
294	i2c_del_adapter(&pcf_isa_ops);
295
296	if (irq > 0) {
297		disable_irq(irq);
298		free_irq(irq, NULL);
299	}
300
301	if (!mmapped) {
302		ioport_unmap(base_iomem);
303		release_region(base, 2);
304	} else {
305		iounmap(base_iomem);
306		release_mem_region(base, 2);
307	}
308
309	return 0;
310}
311
312static struct isa_driver i2c_elektor_driver = {
313	.match		= elektor_match,
314	.probe		= elektor_probe,
315	.remove		= elektor_remove,
316	.driver = {
317		.owner	= THIS_MODULE,
318		.name	= "i2c-elektor",
319	},
320};
321
322static int __init i2c_pcfisa_init(void)
323{
324	return isa_register_driver(&i2c_elektor_driver, 1);
325}
326
327static void __exit i2c_pcfisa_exit(void)
328{
329	isa_unregister_driver(&i2c_elektor_driver);
330}
331
332MODULE_AUTHOR("Hans Berglund <hb@spacetec.no>");
333MODULE_DESCRIPTION("I2C-Bus adapter routines for PCF8584 ISA bus adapter");
334MODULE_LICENSE("GPL");
335
336module_param(base, int, 0);
337module_param(irq, int, 0);
338module_param(clock, int, 0);
339module_param(own, int, 0);
340module_param(mmapped, int, 0);
341
342module_init(i2c_pcfisa_init);
343module_exit(i2c_pcfisa_exit);
344