xref: /openbmc/linux/drivers/i2c/busses/i2c-hydra.c (revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2)
1 /*
2     i2c-hydra.c - Part of lm_sensors,  Linux kernel modules
3                   for hardware monitoring
4 
5     i2c Support for the Apple `Hydra' Mac I/O
6 
7     Copyright (c) 1999-2004 Geert Uytterhoeven <geert@linux-m68k.org>
8 
9     Based on i2c Support for Via Technologies 82C586B South Bridge
10     Copyright (c) 1998, 1999 Ky�sti M�lkki <kmalkki@cc.hut.fi>
11 
12     This program is free software; you can redistribute it and/or modify
13     it under the terms of the GNU General Public License as published by
14     the Free Software Foundation; either version 2 of the License, or
15     (at your option) any later version.
16 
17     This program is distributed in the hope that it will be useful,
18     but WITHOUT ANY WARRANTY; without even the implied warranty of
19     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20     GNU General Public License for more details.
21 
22     You should have received a copy of the GNU General Public License
23     along with this program; if not, write to the Free Software
24     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
25 */
26 
27 #include <linux/kernel.h>
28 #include <linux/module.h>
29 #include <linux/pci.h>
30 #include <linux/types.h>
31 #include <linux/i2c.h>
32 #include <linux/i2c-algo-bit.h>
33 #include <linux/init.h>
34 #include <asm/io.h>
35 #include <asm/hydra.h>
36 
37 
38 #define HYDRA_CPD_PD0	0x00000001	/* CachePD lines */
39 #define HYDRA_CPD_PD1	0x00000002
40 #define HYDRA_CPD_PD2	0x00000004
41 #define HYDRA_CPD_PD3	0x00000008
42 
43 #define HYDRA_SCLK	HYDRA_CPD_PD0
44 #define HYDRA_SDAT	HYDRA_CPD_PD1
45 #define HYDRA_SCLK_OE	0x00000010
46 #define HYDRA_SDAT_OE	0x00000020
47 
48 static inline void pdregw(void *data, u32 val)
49 {
50 	struct Hydra *hydra = (struct Hydra *)data;
51 	writel(val, &hydra->CachePD);
52 }
53 
54 static inline u32 pdregr(void *data)
55 {
56 	struct Hydra *hydra = (struct Hydra *)data;
57 	return readl(&hydra->CachePD);
58 }
59 
60 static void hydra_bit_setscl(void *data, int state)
61 {
62 	u32 val = pdregr(data);
63 	if (state)
64 		val &= ~HYDRA_SCLK_OE;
65 	else {
66 		val &= ~HYDRA_SCLK;
67 		val |= HYDRA_SCLK_OE;
68 	}
69 	pdregw(data, val);
70 }
71 
72 static void hydra_bit_setsda(void *data, int state)
73 {
74 	u32 val = pdregr(data);
75 	if (state)
76 		val &= ~HYDRA_SDAT_OE;
77 	else {
78 		val &= ~HYDRA_SDAT;
79 		val |= HYDRA_SDAT_OE;
80 	}
81 	pdregw(data, val);
82 }
83 
84 static int hydra_bit_getscl(void *data)
85 {
86 	return (pdregr(data) & HYDRA_SCLK) != 0;
87 }
88 
89 static int hydra_bit_getsda(void *data)
90 {
91 	return (pdregr(data) & HYDRA_SDAT) != 0;
92 }
93 
94 /* ------------------------------------------------------------------------ */
95 
96 static struct i2c_algo_bit_data hydra_bit_data = {
97 	.setsda		= hydra_bit_setsda,
98 	.setscl		= hydra_bit_setscl,
99 	.getsda		= hydra_bit_getsda,
100 	.getscl		= hydra_bit_getscl,
101 	.udelay		= 5,
102 	.mdelay		= 5,
103 	.timeout	= HZ
104 };
105 
106 static struct i2c_adapter hydra_adap = {
107 	.owner		= THIS_MODULE,
108 	.name		= "Hydra i2c",
109 	.id		= I2C_HW_B_HYDRA,
110 	.algo_data	= &hydra_bit_data,
111 };
112 
113 static struct pci_device_id hydra_ids[] = {
114 	{ PCI_DEVICE(PCI_VENDOR_ID_APPLE, PCI_DEVICE_ID_APPLE_HYDRA) },
115 	{ 0, }
116 };
117 
118 MODULE_DEVICE_TABLE (pci, hydra_ids);
119 
120 static int __devinit hydra_probe(struct pci_dev *dev,
121 				 const struct pci_device_id *id)
122 {
123 	unsigned long base = pci_resource_start(dev, 0);
124 	int res;
125 
126 	if (!request_mem_region(base+offsetof(struct Hydra, CachePD), 4,
127 				hydra_adap.name))
128 		return -EBUSY;
129 
130 	hydra_bit_data.data = ioremap(base, pci_resource_len(dev, 0));
131 	if (hydra_bit_data.data == NULL) {
132 		release_mem_region(base+offsetof(struct Hydra, CachePD), 4);
133 		return -ENODEV;
134 	}
135 
136 	pdregw(hydra_bit_data.data, 0);		/* clear SCLK_OE and SDAT_OE */
137 	hydra_adap.dev.parent = &dev->dev;
138 	res = i2c_bit_add_bus(&hydra_adap);
139 	if (res < 0) {
140 		iounmap(hydra_bit_data.data);
141 		release_mem_region(base+offsetof(struct Hydra, CachePD), 4);
142 		return res;
143 	}
144 	return 0;
145 }
146 
147 static void __devexit hydra_remove(struct pci_dev *dev)
148 {
149 	pdregw(hydra_bit_data.data, 0);		/* clear SCLK_OE and SDAT_OE */
150 	i2c_bit_del_bus(&hydra_adap);
151 	iounmap(hydra_bit_data.data);
152 	release_mem_region(pci_resource_start(dev, 0)+
153 			   offsetof(struct Hydra, CachePD), 4);
154 }
155 
156 
157 static struct pci_driver hydra_driver = {
158 	.name		= "hydra_smbus",
159 	.id_table	= hydra_ids,
160 	.probe		= hydra_probe,
161 	.remove		= __devexit_p(hydra_remove),
162 };
163 
164 static int __init i2c_hydra_init(void)
165 {
166 	return pci_register_driver(&hydra_driver);
167 }
168 
169 
170 static void __exit i2c_hydra_exit(void)
171 {
172 	pci_unregister_driver(&hydra_driver);
173 }
174 
175 
176 
177 MODULE_AUTHOR("Geert Uytterhoeven <geert@linux-m68k.org>");
178 MODULE_DESCRIPTION("i2c for Apple Hydra Mac I/O");
179 MODULE_LICENSE("GPL");
180 
181 module_init(i2c_hydra_init);
182 module_exit(i2c_hydra_exit);
183 
184