1/*
2 *	matrox_w1.c
3 *
4 * Copyright (c) 2004 Evgeniy Polyakov <johnpol@2ka.mipt.ru>
5 *
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 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 */
21
22#include <asm/types.h>
23#include <asm/atomic.h>
24#include <asm/io.h>
25
26#include <linux/delay.h>
27#include <linux/kernel.h>
28#include <linux/module.h>
29#include <linux/list.h>
30#include <linux/interrupt.h>
31#include <linux/spinlock.h>
32#include <linux/timer.h>
33#include <linux/slab.h>
34#include <linux/pci_ids.h>
35#include <linux/pci.h>
36#include <linux/timer.h>
37
38#include "../w1.h"
39#include "../w1_int.h"
40#include "../w1_log.h"
41
42MODULE_LICENSE("GPL");
43MODULE_AUTHOR("Evgeniy Polyakov <johnpol@2ka.mipt.ru>");
44MODULE_DESCRIPTION("Driver for transport(Dallas 1-wire prtocol) over VGA DDC(matrox gpio).");
45
46static struct pci_device_id matrox_w1_tbl[] = {
47	{ PCI_DEVICE(PCI_VENDOR_ID_MATROX, PCI_DEVICE_ID_MATROX_G400) },
48	{ },
49};
50MODULE_DEVICE_TABLE(pci, matrox_w1_tbl);
51
52static int __devinit matrox_w1_probe(struct pci_dev *, const struct pci_device_id *);
53static void __devexit matrox_w1_remove(struct pci_dev *);
54
55static struct pci_driver matrox_w1_pci_driver = {
56	.name = "matrox_w1",
57	.id_table = matrox_w1_tbl,
58	.probe = matrox_w1_probe,
59	.remove = __devexit_p(matrox_w1_remove),
60};
61
62/*
63 * Matrox G400 DDC registers.
64 */
65
66#define MATROX_G400_DDC_CLK		(1<<4)
67#define MATROX_G400_DDC_DATA		(1<<1)
68
69#define MATROX_BASE			0x3C00
70#define MATROX_STATUS			0x1e14
71
72#define MATROX_PORT_INDEX_OFFSET	0x00
73#define MATROX_PORT_DATA_OFFSET		0x0A
74
75#define MATROX_GET_CONTROL		0x2A
76#define MATROX_GET_DATA			0x2B
77#define MATROX_CURSOR_CTL		0x06
78
79struct matrox_device
80{
81	void __iomem *base_addr;
82	void __iomem *port_index;
83	void __iomem *port_data;
84	u8 data_mask;
85
86	unsigned long phys_addr;
87	void __iomem *virt_addr;
88	unsigned long found;
89
90	struct w1_bus_master *bus_master;
91};
92
93static u8 matrox_w1_read_ddc_bit(void *);
94static void matrox_w1_write_ddc_bit(void *, u8);
95
96/*
97 * These functions read and write DDC Data bit.
98 *
99 * Using tristate pins, since i can't find any open-drain pin in whole motherboard.
100 * Unfortunately we can't connect to Intel's 82801xx IO controller
101 * since we don't know motherboard schema, which has pretty unused(may be not) GPIO.
102 *
103 * I've heard that PIIX also has open drain pin.
104 *
105 * Port mapping.
106 */
107static __inline__ u8 matrox_w1_read_reg(struct matrox_device *dev, u8 reg)
108{
109	u8 ret;
110
111	writeb(reg, dev->port_index);
112	ret = readb(dev->port_data);
113	barrier();
114
115	return ret;
116}
117
118static __inline__ void matrox_w1_write_reg(struct matrox_device *dev, u8 reg, u8 val)
119{
120	writeb(reg, dev->port_index);
121	writeb(val, dev->port_data);
122	wmb();
123}
124
125static void matrox_w1_write_ddc_bit(void *data, u8 bit)
126{
127	u8 ret;
128	struct matrox_device *dev = data;
129
130	if (bit)
131		bit = 0;
132	else
133		bit = dev->data_mask;
134
135	ret = matrox_w1_read_reg(dev, MATROX_GET_CONTROL);
136	matrox_w1_write_reg(dev, MATROX_GET_CONTROL, ((ret & ~dev->data_mask) | bit));
137	matrox_w1_write_reg(dev, MATROX_GET_DATA, 0x00);
138}
139
140static u8 matrox_w1_read_ddc_bit(void *data)
141{
142	u8 ret;
143	struct matrox_device *dev = data;
144
145	ret = matrox_w1_read_reg(dev, MATROX_GET_DATA);
146
147	return ret;
148}
149
150static void matrox_w1_hw_init(struct matrox_device *dev)
151{
152	matrox_w1_write_reg(dev, MATROX_GET_DATA, 0xFF);
153	matrox_w1_write_reg(dev, MATROX_GET_CONTROL, 0x00);
154}
155
156static int __devinit matrox_w1_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
157{
158	struct matrox_device *dev;
159	int err;
160
161	assert(pdev != NULL);
162	assert(ent != NULL);
163
164	if (pdev->vendor != PCI_VENDOR_ID_MATROX || pdev->device != PCI_DEVICE_ID_MATROX_G400)
165		return -ENODEV;
166
167	dev = kmalloc(sizeof(struct matrox_device) +
168		       sizeof(struct w1_bus_master), GFP_KERNEL);
169	if (!dev) {
170		dev_err(&pdev->dev,
171			"%s: Failed to create new matrox_device object.\n",
172			__func__);
173		return -ENOMEM;
174	}
175
176	memset(dev, 0, sizeof(struct matrox_device) + sizeof(struct w1_bus_master));
177
178	dev->bus_master = (struct w1_bus_master *)(dev + 1);
179
180	/*
181	 * True for G400, for some other we need resource 0, see drivers/video/matrox/matroxfb_base.c
182	 */
183
184	dev->phys_addr = pci_resource_start(pdev, 1);
185
186	dev->virt_addr = ioremap_nocache(dev->phys_addr, 16384);
187	if (!dev->virt_addr) {
188		dev_err(&pdev->dev, "%s: failed to ioremap(0x%lx, %d).\n",
189			__func__, dev->phys_addr, 16384);
190		err = -EIO;
191		goto err_out_free_device;
192	}
193
194	dev->base_addr = dev->virt_addr + MATROX_BASE;
195	dev->port_index = dev->base_addr + MATROX_PORT_INDEX_OFFSET;
196	dev->port_data = dev->base_addr + MATROX_PORT_DATA_OFFSET;
197	dev->data_mask = (MATROX_G400_DDC_DATA);
198
199	matrox_w1_hw_init(dev);
200
201	dev->bus_master->data = dev;
202	dev->bus_master->read_bit = &matrox_w1_read_ddc_bit;
203	dev->bus_master->write_bit = &matrox_w1_write_ddc_bit;
204
205	err = w1_add_master_device(dev->bus_master);
206	if (err)
207		goto err_out_free_device;
208
209	pci_set_drvdata(pdev, dev);
210
211	dev->found = 1;
212
213	dev_info(&pdev->dev, "Matrox G400 GPIO transport layer for 1-wire.\n");
214
215	return 0;
216
217err_out_free_device:
218	if (dev->virt_addr)
219		iounmap(dev->virt_addr);
220	kfree(dev);
221
222	return err;
223}
224
225static void __devexit matrox_w1_remove(struct pci_dev *pdev)
226{
227	struct matrox_device *dev = pci_get_drvdata(pdev);
228
229	assert(dev != NULL);
230
231	if (dev->found) {
232		w1_remove_master_device(dev->bus_master);
233		iounmap(dev->virt_addr);
234	}
235	kfree(dev);
236}
237
238static int __init matrox_w1_init(void)
239{
240	return pci_register_driver(&matrox_w1_pci_driver);
241}
242
243static void __exit matrox_w1_fini(void)
244{
245	pci_unregister_driver(&matrox_w1_pci_driver);
246}
247
248module_init(matrox_w1_init);
249module_exit(matrox_w1_fini);
250