xref: /openbmc/linux/drivers/i2c/busses/i2c-hydra.c (revision afb46f79)
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/io.h>
31 #include <asm/hydra.h>
32 
33 
34 #define HYDRA_CPD_PD0	0x00000001	/* CachePD lines */
35 #define HYDRA_CPD_PD1	0x00000002
36 #define HYDRA_CPD_PD2	0x00000004
37 #define HYDRA_CPD_PD3	0x00000008
38 
39 #define HYDRA_SCLK	HYDRA_CPD_PD0
40 #define HYDRA_SDAT	HYDRA_CPD_PD1
41 #define HYDRA_SCLK_OE	0x00000010
42 #define HYDRA_SDAT_OE	0x00000020
43 
44 static inline void pdregw(void *data, u32 val)
45 {
46 	struct Hydra *hydra = (struct Hydra *)data;
47 	writel(val, &hydra->CachePD);
48 }
49 
50 static inline u32 pdregr(void *data)
51 {
52 	struct Hydra *hydra = (struct Hydra *)data;
53 	return readl(&hydra->CachePD);
54 }
55 
56 static void hydra_bit_setscl(void *data, int state)
57 {
58 	u32 val = pdregr(data);
59 	if (state)
60 		val &= ~HYDRA_SCLK_OE;
61 	else {
62 		val &= ~HYDRA_SCLK;
63 		val |= HYDRA_SCLK_OE;
64 	}
65 	pdregw(data, val);
66 }
67 
68 static void hydra_bit_setsda(void *data, int state)
69 {
70 	u32 val = pdregr(data);
71 	if (state)
72 		val &= ~HYDRA_SDAT_OE;
73 	else {
74 		val &= ~HYDRA_SDAT;
75 		val |= HYDRA_SDAT_OE;
76 	}
77 	pdregw(data, val);
78 }
79 
80 static int hydra_bit_getscl(void *data)
81 {
82 	return (pdregr(data) & HYDRA_SCLK) != 0;
83 }
84 
85 static int hydra_bit_getsda(void *data)
86 {
87 	return (pdregr(data) & HYDRA_SDAT) != 0;
88 }
89 
90 /* ------------------------------------------------------------------------ */
91 
92 static struct i2c_algo_bit_data hydra_bit_data = {
93 	.setsda		= hydra_bit_setsda,
94 	.setscl		= hydra_bit_setscl,
95 	.getsda		= hydra_bit_getsda,
96 	.getscl		= hydra_bit_getscl,
97 	.udelay		= 5,
98 	.timeout	= HZ
99 };
100 
101 static struct i2c_adapter hydra_adap = {
102 	.owner		= THIS_MODULE,
103 	.name		= "Hydra i2c",
104 	.algo_data	= &hydra_bit_data,
105 };
106 
107 static const struct pci_device_id hydra_ids[] = {
108 	{ PCI_DEVICE(PCI_VENDOR_ID_APPLE, PCI_DEVICE_ID_APPLE_HYDRA) },
109 	{ 0, }
110 };
111 
112 MODULE_DEVICE_TABLE (pci, hydra_ids);
113 
114 static int hydra_probe(struct pci_dev *dev,
115 				 const struct pci_device_id *id)
116 {
117 	unsigned long base = pci_resource_start(dev, 0);
118 	int res;
119 
120 	if (!request_mem_region(base+offsetof(struct Hydra, CachePD), 4,
121 				hydra_adap.name))
122 		return -EBUSY;
123 
124 	hydra_bit_data.data = pci_ioremap_bar(dev, 0);
125 	if (hydra_bit_data.data == NULL) {
126 		release_mem_region(base+offsetof(struct Hydra, CachePD), 4);
127 		return -ENODEV;
128 	}
129 
130 	pdregw(hydra_bit_data.data, 0);		/* clear SCLK_OE and SDAT_OE */
131 	hydra_adap.dev.parent = &dev->dev;
132 	res = i2c_bit_add_bus(&hydra_adap);
133 	if (res < 0) {
134 		iounmap(hydra_bit_data.data);
135 		release_mem_region(base+offsetof(struct Hydra, CachePD), 4);
136 		return res;
137 	}
138 	return 0;
139 }
140 
141 static void hydra_remove(struct pci_dev *dev)
142 {
143 	pdregw(hydra_bit_data.data, 0);		/* clear SCLK_OE and SDAT_OE */
144 	i2c_del_adapter(&hydra_adap);
145 	iounmap(hydra_bit_data.data);
146 	release_mem_region(pci_resource_start(dev, 0)+
147 			   offsetof(struct Hydra, CachePD), 4);
148 }
149 
150 
151 static struct pci_driver hydra_driver = {
152 	.name		= "hydra_smbus",
153 	.id_table	= hydra_ids,
154 	.probe		= hydra_probe,
155 	.remove		= hydra_remove,
156 };
157 
158 module_pci_driver(hydra_driver);
159 
160 MODULE_AUTHOR("Geert Uytterhoeven <geert@linux-m68k.org>");
161 MODULE_DESCRIPTION("i2c for Apple Hydra Mac I/O");
162 MODULE_LICENSE("GPL");
163