xref: /openbmc/linux/drivers/i2c/busses/i2c-hydra.c (revision e3b9f1e8)
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 
20 #include <linux/kernel.h>
21 #include <linux/module.h>
22 #include <linux/pci.h>
23 #include <linux/types.h>
24 #include <linux/i2c.h>
25 #include <linux/i2c-algo-bit.h>
26 #include <linux/io.h>
27 #include <asm/hydra.h>
28 
29 
30 #define HYDRA_CPD_PD0	0x00000001	/* CachePD lines */
31 #define HYDRA_CPD_PD1	0x00000002
32 #define HYDRA_CPD_PD2	0x00000004
33 #define HYDRA_CPD_PD3	0x00000008
34 
35 #define HYDRA_SCLK	HYDRA_CPD_PD0
36 #define HYDRA_SDAT	HYDRA_CPD_PD1
37 #define HYDRA_SCLK_OE	0x00000010
38 #define HYDRA_SDAT_OE	0x00000020
39 
40 static inline void pdregw(void *data, u32 val)
41 {
42 	struct Hydra *hydra = (struct Hydra *)data;
43 	writel(val, &hydra->CachePD);
44 }
45 
46 static inline u32 pdregr(void *data)
47 {
48 	struct Hydra *hydra = (struct Hydra *)data;
49 	return readl(&hydra->CachePD);
50 }
51 
52 static void hydra_bit_setscl(void *data, int state)
53 {
54 	u32 val = pdregr(data);
55 	if (state)
56 		val &= ~HYDRA_SCLK_OE;
57 	else {
58 		val &= ~HYDRA_SCLK;
59 		val |= HYDRA_SCLK_OE;
60 	}
61 	pdregw(data, val);
62 }
63 
64 static void hydra_bit_setsda(void *data, int state)
65 {
66 	u32 val = pdregr(data);
67 	if (state)
68 		val &= ~HYDRA_SDAT_OE;
69 	else {
70 		val &= ~HYDRA_SDAT;
71 		val |= HYDRA_SDAT_OE;
72 	}
73 	pdregw(data, val);
74 }
75 
76 static int hydra_bit_getscl(void *data)
77 {
78 	return (pdregr(data) & HYDRA_SCLK) != 0;
79 }
80 
81 static int hydra_bit_getsda(void *data)
82 {
83 	return (pdregr(data) & HYDRA_SDAT) != 0;
84 }
85 
86 /* ------------------------------------------------------------------------ */
87 
88 static struct i2c_algo_bit_data hydra_bit_data = {
89 	.setsda		= hydra_bit_setsda,
90 	.setscl		= hydra_bit_setscl,
91 	.getsda		= hydra_bit_getsda,
92 	.getscl		= hydra_bit_getscl,
93 	.udelay		= 5,
94 	.timeout	= HZ
95 };
96 
97 static struct i2c_adapter hydra_adap = {
98 	.owner		= THIS_MODULE,
99 	.name		= "Hydra i2c",
100 	.algo_data	= &hydra_bit_data,
101 };
102 
103 static const struct pci_device_id hydra_ids[] = {
104 	{ PCI_DEVICE(PCI_VENDOR_ID_APPLE, PCI_DEVICE_ID_APPLE_HYDRA) },
105 	{ 0, }
106 };
107 
108 MODULE_DEVICE_TABLE (pci, hydra_ids);
109 
110 static int hydra_probe(struct pci_dev *dev,
111 				 const struct pci_device_id *id)
112 {
113 	unsigned long base = pci_resource_start(dev, 0);
114 	int res;
115 
116 	if (!request_mem_region(base+offsetof(struct Hydra, CachePD), 4,
117 				hydra_adap.name))
118 		return -EBUSY;
119 
120 	hydra_bit_data.data = pci_ioremap_bar(dev, 0);
121 	if (hydra_bit_data.data == NULL) {
122 		release_mem_region(base+offsetof(struct Hydra, CachePD), 4);
123 		return -ENODEV;
124 	}
125 
126 	pdregw(hydra_bit_data.data, 0);		/* clear SCLK_OE and SDAT_OE */
127 	hydra_adap.dev.parent = &dev->dev;
128 	res = i2c_bit_add_bus(&hydra_adap);
129 	if (res < 0) {
130 		iounmap(hydra_bit_data.data);
131 		release_mem_region(base+offsetof(struct Hydra, CachePD), 4);
132 		return res;
133 	}
134 	return 0;
135 }
136 
137 static void hydra_remove(struct pci_dev *dev)
138 {
139 	pdregw(hydra_bit_data.data, 0);		/* clear SCLK_OE and SDAT_OE */
140 	i2c_del_adapter(&hydra_adap);
141 	iounmap(hydra_bit_data.data);
142 	release_mem_region(pci_resource_start(dev, 0)+
143 			   offsetof(struct Hydra, CachePD), 4);
144 }
145 
146 
147 static struct pci_driver hydra_driver = {
148 	.name		= "hydra_smbus",
149 	.id_table	= hydra_ids,
150 	.probe		= hydra_probe,
151 	.remove		= hydra_remove,
152 };
153 
154 module_pci_driver(hydra_driver);
155 
156 MODULE_AUTHOR("Geert Uytterhoeven <geert@linux-m68k.org>");
157 MODULE_DESCRIPTION("i2c for Apple Hydra Mac I/O");
158 MODULE_LICENSE("GPL");
159