xref: /openbmc/linux/drivers/w1/masters/matrox_w1.c (revision a36954f5)
1 /*
2  *	matrox_w1.c
3  *
4  * Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net>
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 <linux/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 
37 #include "../w1.h"
38 #include "../w1_int.h"
39 
40 /*
41  * Matrox G400 DDC registers.
42  */
43 
44 #define MATROX_G400_DDC_CLK		(1<<4)
45 #define MATROX_G400_DDC_DATA		(1<<1)
46 
47 #define MATROX_BASE			0x3C00
48 #define MATROX_STATUS			0x1e14
49 
50 #define MATROX_PORT_INDEX_OFFSET	0x00
51 #define MATROX_PORT_DATA_OFFSET		0x0A
52 
53 #define MATROX_GET_CONTROL		0x2A
54 #define MATROX_GET_DATA			0x2B
55 #define MATROX_CURSOR_CTL		0x06
56 
57 struct matrox_device
58 {
59 	void __iomem *base_addr;
60 	void __iomem *port_index;
61 	void __iomem *port_data;
62 	u8 data_mask;
63 
64 	unsigned long phys_addr;
65 	void __iomem *virt_addr;
66 	unsigned long found;
67 
68 	struct w1_bus_master *bus_master;
69 };
70 
71 /*
72  * These functions read and write DDC Data bit.
73  *
74  * Using tristate pins, since i can't find any open-drain pin in whole motherboard.
75  * Unfortunately we can't connect to Intel's 82801xx IO controller
76  * since we don't know motherboard schema, which has pretty unused(may be not) GPIO.
77  *
78  * I've heard that PIIX also has open drain pin.
79  *
80  * Port mapping.
81  */
82 static __inline__ u8 matrox_w1_read_reg(struct matrox_device *dev, u8 reg)
83 {
84 	u8 ret;
85 
86 	writeb(reg, dev->port_index);
87 	ret = readb(dev->port_data);
88 	barrier();
89 
90 	return ret;
91 }
92 
93 static __inline__ void matrox_w1_write_reg(struct matrox_device *dev, u8 reg, u8 val)
94 {
95 	writeb(reg, dev->port_index);
96 	writeb(val, dev->port_data);
97 	wmb();
98 }
99 
100 static void matrox_w1_write_ddc_bit(void *data, u8 bit)
101 {
102 	u8 ret;
103 	struct matrox_device *dev = data;
104 
105 	if (bit)
106 		bit = 0;
107 	else
108 		bit = dev->data_mask;
109 
110 	ret = matrox_w1_read_reg(dev, MATROX_GET_CONTROL);
111 	matrox_w1_write_reg(dev, MATROX_GET_CONTROL, ((ret & ~dev->data_mask) | bit));
112 	matrox_w1_write_reg(dev, MATROX_GET_DATA, 0x00);
113 }
114 
115 static u8 matrox_w1_read_ddc_bit(void *data)
116 {
117 	u8 ret;
118 	struct matrox_device *dev = data;
119 
120 	ret = matrox_w1_read_reg(dev, MATROX_GET_DATA);
121 
122 	return ret;
123 }
124 
125 static void matrox_w1_hw_init(struct matrox_device *dev)
126 {
127 	matrox_w1_write_reg(dev, MATROX_GET_DATA, 0xFF);
128 	matrox_w1_write_reg(dev, MATROX_GET_CONTROL, 0x00);
129 }
130 
131 static int matrox_w1_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
132 {
133 	struct matrox_device *dev;
134 	int err;
135 
136 	if (pdev->vendor != PCI_VENDOR_ID_MATROX || pdev->device != PCI_DEVICE_ID_MATROX_G400)
137 		return -ENODEV;
138 
139 	dev = kzalloc(sizeof(struct matrox_device) +
140 		       sizeof(struct w1_bus_master), GFP_KERNEL);
141 	if (!dev) {
142 		dev_err(&pdev->dev,
143 			"%s: Failed to create new matrox_device object.\n",
144 			__func__);
145 		return -ENOMEM;
146 	}
147 
148 
149 	dev->bus_master = (struct w1_bus_master *)(dev + 1);
150 
151 	/*
152 	 * True for G400, for some other we need resource 0, see drivers/video/matrox/matroxfb_base.c
153 	 */
154 
155 	dev->phys_addr = pci_resource_start(pdev, 1);
156 
157 	dev->virt_addr = ioremap_nocache(dev->phys_addr, 16384);
158 	if (!dev->virt_addr) {
159 		dev_err(&pdev->dev, "%s: failed to ioremap(0x%lx, %d).\n",
160 			__func__, dev->phys_addr, 16384);
161 		err = -EIO;
162 		goto err_out_free_device;
163 	}
164 
165 	dev->base_addr = dev->virt_addr + MATROX_BASE;
166 	dev->port_index = dev->base_addr + MATROX_PORT_INDEX_OFFSET;
167 	dev->port_data = dev->base_addr + MATROX_PORT_DATA_OFFSET;
168 	dev->data_mask = (MATROX_G400_DDC_DATA);
169 
170 	matrox_w1_hw_init(dev);
171 
172 	dev->bus_master->data = dev;
173 	dev->bus_master->read_bit = &matrox_w1_read_ddc_bit;
174 	dev->bus_master->write_bit = &matrox_w1_write_ddc_bit;
175 
176 	err = w1_add_master_device(dev->bus_master);
177 	if (err)
178 		goto err_out_free_device;
179 
180 	pci_set_drvdata(pdev, dev);
181 
182 	dev->found = 1;
183 
184 	dev_info(&pdev->dev, "Matrox G400 GPIO transport layer for 1-wire.\n");
185 
186 	return 0;
187 
188 err_out_free_device:
189 	if (dev->virt_addr)
190 		iounmap(dev->virt_addr);
191 	kfree(dev);
192 
193 	return err;
194 }
195 
196 static void matrox_w1_remove(struct pci_dev *pdev)
197 {
198 	struct matrox_device *dev = pci_get_drvdata(pdev);
199 
200 	if (dev->found) {
201 		w1_remove_master_device(dev->bus_master);
202 		iounmap(dev->virt_addr);
203 	}
204 	kfree(dev);
205 }
206 
207 static struct pci_device_id matrox_w1_tbl[] = {
208 	{ PCI_DEVICE(PCI_VENDOR_ID_MATROX, PCI_DEVICE_ID_MATROX_G400) },
209 	{ },
210 };
211 MODULE_DEVICE_TABLE(pci, matrox_w1_tbl);
212 
213 static struct pci_driver matrox_w1_pci_driver = {
214 	.name = "matrox_w1",
215 	.id_table = matrox_w1_tbl,
216 	.probe = matrox_w1_probe,
217 	.remove = matrox_w1_remove,
218 };
219 module_pci_driver(matrox_w1_pci_driver);
220 
221 MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>");
222 MODULE_DESCRIPTION("Driver for transport(Dallas 1-wire protocol) over VGA DDC(matrox gpio).");
223 MODULE_LICENSE("GPL");
224