xref: /openbmc/linux/drivers/i2c/busses/i2c-hydra.c (revision 54cbac81)
1 /*
2     i2c Support for the Apple `Hydra' Mac I/O
3 
4     Copyright (c) 1999-2004 Geert Uytterhoeven <geert@linux-m68k.org>
5 
6     Based on i2c Support for Via Technologies 82C586B South Bridge
7     Copyright (c) 1998, 1999 Kyösti Mälkki <kmalkki@cc.hut.fi>
8 
9     This program is free software; you can redistribute it and/or modify
10     it under the terms of the GNU General Public License as published by
11     the Free Software Foundation; either version 2 of the License, or
12     (at your option) any later version.
13 
14     This program is distributed in the hope that it will be useful,
15     but WITHOUT ANY WARRANTY; without even the implied warranty of
16     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17     GNU General Public License for more details.
18 
19     You should have received a copy of the GNU General Public License
20     along with this program; if not, write to the Free Software
21     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22 */
23 
24 #include <linux/kernel.h>
25 #include <linux/module.h>
26 #include <linux/pci.h>
27 #include <linux/types.h>
28 #include <linux/i2c.h>
29 #include <linux/i2c-algo-bit.h>
30 #include <linux/init.h>
31 #include <linux/io.h>
32 #include <asm/hydra.h>
33 
34 
35 #define HYDRA_CPD_PD0	0x00000001	/* CachePD lines */
36 #define HYDRA_CPD_PD1	0x00000002
37 #define HYDRA_CPD_PD2	0x00000004
38 #define HYDRA_CPD_PD3	0x00000008
39 
40 #define HYDRA_SCLK	HYDRA_CPD_PD0
41 #define HYDRA_SDAT	HYDRA_CPD_PD1
42 #define HYDRA_SCLK_OE	0x00000010
43 #define HYDRA_SDAT_OE	0x00000020
44 
45 static inline void pdregw(void *data, u32 val)
46 {
47 	struct Hydra *hydra = (struct Hydra *)data;
48 	writel(val, &hydra->CachePD);
49 }
50 
51 static inline u32 pdregr(void *data)
52 {
53 	struct Hydra *hydra = (struct Hydra *)data;
54 	return readl(&hydra->CachePD);
55 }
56 
57 static void hydra_bit_setscl(void *data, int state)
58 {
59 	u32 val = pdregr(data);
60 	if (state)
61 		val &= ~HYDRA_SCLK_OE;
62 	else {
63 		val &= ~HYDRA_SCLK;
64 		val |= HYDRA_SCLK_OE;
65 	}
66 	pdregw(data, val);
67 }
68 
69 static void hydra_bit_setsda(void *data, int state)
70 {
71 	u32 val = pdregr(data);
72 	if (state)
73 		val &= ~HYDRA_SDAT_OE;
74 	else {
75 		val &= ~HYDRA_SDAT;
76 		val |= HYDRA_SDAT_OE;
77 	}
78 	pdregw(data, val);
79 }
80 
81 static int hydra_bit_getscl(void *data)
82 {
83 	return (pdregr(data) & HYDRA_SCLK) != 0;
84 }
85 
86 static int hydra_bit_getsda(void *data)
87 {
88 	return (pdregr(data) & HYDRA_SDAT) != 0;
89 }
90 
91 /* ------------------------------------------------------------------------ */
92 
93 static struct i2c_algo_bit_data hydra_bit_data = {
94 	.setsda		= hydra_bit_setsda,
95 	.setscl		= hydra_bit_setscl,
96 	.getsda		= hydra_bit_getsda,
97 	.getscl		= hydra_bit_getscl,
98 	.udelay		= 5,
99 	.timeout	= HZ
100 };
101 
102 static struct i2c_adapter hydra_adap = {
103 	.owner		= THIS_MODULE,
104 	.name		= "Hydra i2c",
105 	.algo_data	= &hydra_bit_data,
106 };
107 
108 static DEFINE_PCI_DEVICE_TABLE(hydra_ids) = {
109 	{ PCI_DEVICE(PCI_VENDOR_ID_APPLE, PCI_DEVICE_ID_APPLE_HYDRA) },
110 	{ 0, }
111 };
112 
113 MODULE_DEVICE_TABLE (pci, hydra_ids);
114 
115 static int hydra_probe(struct pci_dev *dev,
116 				 const struct pci_device_id *id)
117 {
118 	unsigned long base = pci_resource_start(dev, 0);
119 	int res;
120 
121 	if (!request_mem_region(base+offsetof(struct Hydra, CachePD), 4,
122 				hydra_adap.name))
123 		return -EBUSY;
124 
125 	hydra_bit_data.data = pci_ioremap_bar(dev, 0);
126 	if (hydra_bit_data.data == NULL) {
127 		release_mem_region(base+offsetof(struct Hydra, CachePD), 4);
128 		return -ENODEV;
129 	}
130 
131 	pdregw(hydra_bit_data.data, 0);		/* clear SCLK_OE and SDAT_OE */
132 	hydra_adap.dev.parent = &dev->dev;
133 	res = i2c_bit_add_bus(&hydra_adap);
134 	if (res < 0) {
135 		iounmap(hydra_bit_data.data);
136 		release_mem_region(base+offsetof(struct Hydra, CachePD), 4);
137 		return res;
138 	}
139 	return 0;
140 }
141 
142 static void hydra_remove(struct pci_dev *dev)
143 {
144 	pdregw(hydra_bit_data.data, 0);		/* clear SCLK_OE and SDAT_OE */
145 	i2c_del_adapter(&hydra_adap);
146 	iounmap(hydra_bit_data.data);
147 	release_mem_region(pci_resource_start(dev, 0)+
148 			   offsetof(struct Hydra, CachePD), 4);
149 }
150 
151 
152 static struct pci_driver hydra_driver = {
153 	.name		= "hydra_smbus",
154 	.id_table	= hydra_ids,
155 	.probe		= hydra_probe,
156 	.remove		= hydra_remove,
157 };
158 
159 module_pci_driver(hydra_driver);
160 
161 MODULE_AUTHOR("Geert Uytterhoeven <geert@linux-m68k.org>");
162 MODULE_DESCRIPTION("i2c for Apple Hydra Mac I/O");
163 MODULE_LICENSE("GPL");
164