xref: /openbmc/linux/drivers/w1/masters/matrox_w1.c (revision 4f6cce39)
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 #include "../w1_log.h"
40 
41 MODULE_LICENSE("GPL");
42 MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>");
43 MODULE_DESCRIPTION("Driver for transport(Dallas 1-wire protocol) over VGA DDC(matrox gpio).");
44 
45 static struct pci_device_id matrox_w1_tbl[] = {
46 	{ PCI_DEVICE(PCI_VENDOR_ID_MATROX, PCI_DEVICE_ID_MATROX_G400) },
47 	{ },
48 };
49 MODULE_DEVICE_TABLE(pci, matrox_w1_tbl);
50 
51 static int matrox_w1_probe(struct pci_dev *, const struct pci_device_id *);
52 static void matrox_w1_remove(struct pci_dev *);
53 
54 static struct pci_driver matrox_w1_pci_driver = {
55 	.name = "matrox_w1",
56 	.id_table = matrox_w1_tbl,
57 	.probe = matrox_w1_probe,
58 	.remove = matrox_w1_remove,
59 };
60 
61 /*
62  * Matrox G400 DDC registers.
63  */
64 
65 #define MATROX_G400_DDC_CLK		(1<<4)
66 #define MATROX_G400_DDC_DATA		(1<<1)
67 
68 #define MATROX_BASE			0x3C00
69 #define MATROX_STATUS			0x1e14
70 
71 #define MATROX_PORT_INDEX_OFFSET	0x00
72 #define MATROX_PORT_DATA_OFFSET		0x0A
73 
74 #define MATROX_GET_CONTROL		0x2A
75 #define MATROX_GET_DATA			0x2B
76 #define MATROX_CURSOR_CTL		0x06
77 
78 struct matrox_device
79 {
80 	void __iomem *base_addr;
81 	void __iomem *port_index;
82 	void __iomem *port_data;
83 	u8 data_mask;
84 
85 	unsigned long phys_addr;
86 	void __iomem *virt_addr;
87 	unsigned long found;
88 
89 	struct w1_bus_master *bus_master;
90 };
91 
92 static u8 matrox_w1_read_ddc_bit(void *);
93 static void matrox_w1_write_ddc_bit(void *, u8);
94 
95 /*
96  * These functions read and write DDC Data bit.
97  *
98  * Using tristate pins, since i can't find any open-drain pin in whole motherboard.
99  * Unfortunately we can't connect to Intel's 82801xx IO controller
100  * since we don't know motherboard schema, which has pretty unused(may be not) GPIO.
101  *
102  * I've heard that PIIX also has open drain pin.
103  *
104  * Port mapping.
105  */
106 static __inline__ u8 matrox_w1_read_reg(struct matrox_device *dev, u8 reg)
107 {
108 	u8 ret;
109 
110 	writeb(reg, dev->port_index);
111 	ret = readb(dev->port_data);
112 	barrier();
113 
114 	return ret;
115 }
116 
117 static __inline__ void matrox_w1_write_reg(struct matrox_device *dev, u8 reg, u8 val)
118 {
119 	writeb(reg, dev->port_index);
120 	writeb(val, dev->port_data);
121 	wmb();
122 }
123 
124 static void matrox_w1_write_ddc_bit(void *data, u8 bit)
125 {
126 	u8 ret;
127 	struct matrox_device *dev = data;
128 
129 	if (bit)
130 		bit = 0;
131 	else
132 		bit = dev->data_mask;
133 
134 	ret = matrox_w1_read_reg(dev, MATROX_GET_CONTROL);
135 	matrox_w1_write_reg(dev, MATROX_GET_CONTROL, ((ret & ~dev->data_mask) | bit));
136 	matrox_w1_write_reg(dev, MATROX_GET_DATA, 0x00);
137 }
138 
139 static u8 matrox_w1_read_ddc_bit(void *data)
140 {
141 	u8 ret;
142 	struct matrox_device *dev = data;
143 
144 	ret = matrox_w1_read_reg(dev, MATROX_GET_DATA);
145 
146 	return ret;
147 }
148 
149 static void matrox_w1_hw_init(struct matrox_device *dev)
150 {
151 	matrox_w1_write_reg(dev, MATROX_GET_DATA, 0xFF);
152 	matrox_w1_write_reg(dev, MATROX_GET_CONTROL, 0x00);
153 }
154 
155 static int matrox_w1_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
156 {
157 	struct matrox_device *dev;
158 	int err;
159 
160 	assert(pdev != NULL);
161 	assert(ent != NULL);
162 
163 	if (pdev->vendor != PCI_VENDOR_ID_MATROX || pdev->device != PCI_DEVICE_ID_MATROX_G400)
164 		return -ENODEV;
165 
166 	dev = kzalloc(sizeof(struct matrox_device) +
167 		       sizeof(struct w1_bus_master), GFP_KERNEL);
168 	if (!dev) {
169 		dev_err(&pdev->dev,
170 			"%s: Failed to create new matrox_device object.\n",
171 			__func__);
172 		return -ENOMEM;
173 	}
174 
175 
176 	dev->bus_master = (struct w1_bus_master *)(dev + 1);
177 
178 	/*
179 	 * True for G400, for some other we need resource 0, see drivers/video/matrox/matroxfb_base.c
180 	 */
181 
182 	dev->phys_addr = pci_resource_start(pdev, 1);
183 
184 	dev->virt_addr = ioremap_nocache(dev->phys_addr, 16384);
185 	if (!dev->virt_addr) {
186 		dev_err(&pdev->dev, "%s: failed to ioremap(0x%lx, %d).\n",
187 			__func__, dev->phys_addr, 16384);
188 		err = -EIO;
189 		goto err_out_free_device;
190 	}
191 
192 	dev->base_addr = dev->virt_addr + MATROX_BASE;
193 	dev->port_index = dev->base_addr + MATROX_PORT_INDEX_OFFSET;
194 	dev->port_data = dev->base_addr + MATROX_PORT_DATA_OFFSET;
195 	dev->data_mask = (MATROX_G400_DDC_DATA);
196 
197 	matrox_w1_hw_init(dev);
198 
199 	dev->bus_master->data = dev;
200 	dev->bus_master->read_bit = &matrox_w1_read_ddc_bit;
201 	dev->bus_master->write_bit = &matrox_w1_write_ddc_bit;
202 
203 	err = w1_add_master_device(dev->bus_master);
204 	if (err)
205 		goto err_out_free_device;
206 
207 	pci_set_drvdata(pdev, dev);
208 
209 	dev->found = 1;
210 
211 	dev_info(&pdev->dev, "Matrox G400 GPIO transport layer for 1-wire.\n");
212 
213 	return 0;
214 
215 err_out_free_device:
216 	if (dev->virt_addr)
217 		iounmap(dev->virt_addr);
218 	kfree(dev);
219 
220 	return err;
221 }
222 
223 static void matrox_w1_remove(struct pci_dev *pdev)
224 {
225 	struct matrox_device *dev = pci_get_drvdata(pdev);
226 
227 	assert(dev != NULL);
228 
229 	if (dev->found) {
230 		w1_remove_master_device(dev->bus_master);
231 		iounmap(dev->virt_addr);
232 	}
233 	kfree(dev);
234 }
235 module_pci_driver(matrox_w1_pci_driver);
236