xref: /openbmc/linux/drivers/w1/masters/matrox_w1.c (revision 791d3ef2)
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 <linux/w1.h>
38 
39 /*
40  * Matrox G400 DDC registers.
41  */
42 
43 #define MATROX_G400_DDC_CLK		(1<<4)
44 #define MATROX_G400_DDC_DATA		(1<<1)
45 
46 #define MATROX_BASE			0x3C00
47 #define MATROX_STATUS			0x1e14
48 
49 #define MATROX_PORT_INDEX_OFFSET	0x00
50 #define MATROX_PORT_DATA_OFFSET		0x0A
51 
52 #define MATROX_GET_CONTROL		0x2A
53 #define MATROX_GET_DATA			0x2B
54 #define MATROX_CURSOR_CTL		0x06
55 
56 struct matrox_device
57 {
58 	void __iomem *base_addr;
59 	void __iomem *port_index;
60 	void __iomem *port_data;
61 	u8 data_mask;
62 
63 	unsigned long phys_addr;
64 	void __iomem *virt_addr;
65 	unsigned long found;
66 
67 	struct w1_bus_master *bus_master;
68 };
69 
70 /*
71  * These functions read and write DDC Data bit.
72  *
73  * Using tristate pins, since i can't find any open-drain pin in whole motherboard.
74  * Unfortunately we can't connect to Intel's 82801xx IO controller
75  * since we don't know motherboard schema, which has pretty unused(may be not) GPIO.
76  *
77  * I've heard that PIIX also has open drain pin.
78  *
79  * Port mapping.
80  */
81 static __inline__ u8 matrox_w1_read_reg(struct matrox_device *dev, u8 reg)
82 {
83 	u8 ret;
84 
85 	writeb(reg, dev->port_index);
86 	ret = readb(dev->port_data);
87 	barrier();
88 
89 	return ret;
90 }
91 
92 static __inline__ void matrox_w1_write_reg(struct matrox_device *dev, u8 reg, u8 val)
93 {
94 	writeb(reg, dev->port_index);
95 	writeb(val, dev->port_data);
96 	wmb();
97 }
98 
99 static void matrox_w1_write_ddc_bit(void *data, u8 bit)
100 {
101 	u8 ret;
102 	struct matrox_device *dev = data;
103 
104 	if (bit)
105 		bit = 0;
106 	else
107 		bit = dev->data_mask;
108 
109 	ret = matrox_w1_read_reg(dev, MATROX_GET_CONTROL);
110 	matrox_w1_write_reg(dev, MATROX_GET_CONTROL, ((ret & ~dev->data_mask) | bit));
111 	matrox_w1_write_reg(dev, MATROX_GET_DATA, 0x00);
112 }
113 
114 static u8 matrox_w1_read_ddc_bit(void *data)
115 {
116 	u8 ret;
117 	struct matrox_device *dev = data;
118 
119 	ret = matrox_w1_read_reg(dev, MATROX_GET_DATA);
120 
121 	return ret;
122 }
123 
124 static void matrox_w1_hw_init(struct matrox_device *dev)
125 {
126 	matrox_w1_write_reg(dev, MATROX_GET_DATA, 0xFF);
127 	matrox_w1_write_reg(dev, MATROX_GET_CONTROL, 0x00);
128 }
129 
130 static int matrox_w1_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
131 {
132 	struct matrox_device *dev;
133 	int err;
134 
135 	if (pdev->vendor != PCI_VENDOR_ID_MATROX || pdev->device != PCI_DEVICE_ID_MATROX_G400)
136 		return -ENODEV;
137 
138 	dev = kzalloc(sizeof(struct matrox_device) +
139 		       sizeof(struct w1_bus_master), GFP_KERNEL);
140 	if (!dev) {
141 		dev_err(&pdev->dev,
142 			"%s: Failed to create new matrox_device object.\n",
143 			__func__);
144 		return -ENOMEM;
145 	}
146 
147 
148 	dev->bus_master = (struct w1_bus_master *)(dev + 1);
149 
150 	/*
151 	 * True for G400, for some other we need resource 0, see drivers/video/matrox/matroxfb_base.c
152 	 */
153 
154 	dev->phys_addr = pci_resource_start(pdev, 1);
155 
156 	dev->virt_addr = ioremap_nocache(dev->phys_addr, 16384);
157 	if (!dev->virt_addr) {
158 		dev_err(&pdev->dev, "%s: failed to ioremap(0x%lx, %d).\n",
159 			__func__, dev->phys_addr, 16384);
160 		err = -EIO;
161 		goto err_out_free_device;
162 	}
163 
164 	dev->base_addr = dev->virt_addr + MATROX_BASE;
165 	dev->port_index = dev->base_addr + MATROX_PORT_INDEX_OFFSET;
166 	dev->port_data = dev->base_addr + MATROX_PORT_DATA_OFFSET;
167 	dev->data_mask = (MATROX_G400_DDC_DATA);
168 
169 	matrox_w1_hw_init(dev);
170 
171 	dev->bus_master->data = dev;
172 	dev->bus_master->read_bit = &matrox_w1_read_ddc_bit;
173 	dev->bus_master->write_bit = &matrox_w1_write_ddc_bit;
174 
175 	err = w1_add_master_device(dev->bus_master);
176 	if (err)
177 		goto err_out_free_device;
178 
179 	pci_set_drvdata(pdev, dev);
180 
181 	dev->found = 1;
182 
183 	dev_info(&pdev->dev, "Matrox G400 GPIO transport layer for 1-wire.\n");
184 
185 	return 0;
186 
187 err_out_free_device:
188 	if (dev->virt_addr)
189 		iounmap(dev->virt_addr);
190 	kfree(dev);
191 
192 	return err;
193 }
194 
195 static void matrox_w1_remove(struct pci_dev *pdev)
196 {
197 	struct matrox_device *dev = pci_get_drvdata(pdev);
198 
199 	if (dev->found) {
200 		w1_remove_master_device(dev->bus_master);
201 		iounmap(dev->virt_addr);
202 	}
203 	kfree(dev);
204 }
205 
206 static struct pci_device_id matrox_w1_tbl[] = {
207 	{ PCI_DEVICE(PCI_VENDOR_ID_MATROX, PCI_DEVICE_ID_MATROX_G400) },
208 	{ },
209 };
210 MODULE_DEVICE_TABLE(pci, matrox_w1_tbl);
211 
212 static struct pci_driver matrox_w1_pci_driver = {
213 	.name = "matrox_w1",
214 	.id_table = matrox_w1_tbl,
215 	.probe = matrox_w1_probe,
216 	.remove = matrox_w1_remove,
217 };
218 module_pci_driver(matrox_w1_pci_driver);
219 
220 MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>");
221 MODULE_DESCRIPTION("Driver for transport(Dallas 1-wire protocol) over VGA DDC(matrox gpio).");
222 MODULE_LICENSE("GPL");
223