1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 i2c Support for the Apple `Hydra' Mac I/O
4
5 Copyright (c) 1999-2004 Geert Uytterhoeven <geert@linux-m68k.org>
6
7 Based on i2c Support for Via Technologies 82C586B South Bridge
8 Copyright (c) 1998, 1999 Kyösti Mälkki <kmalkki@cc.hut.fi>
9
10 */
11
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/pci.h>
15 #include <linux/types.h>
16 #include <linux/i2c.h>
17 #include <linux/i2c-algo-bit.h>
18 #include <linux/io.h>
19 #include <asm/hydra.h>
20
21
22 #define HYDRA_CPD_PD0 0x00000001 /* CachePD lines */
23 #define HYDRA_CPD_PD1 0x00000002
24 #define HYDRA_CPD_PD2 0x00000004
25 #define HYDRA_CPD_PD3 0x00000008
26
27 #define HYDRA_SCLK HYDRA_CPD_PD0
28 #define HYDRA_SDAT HYDRA_CPD_PD1
29 #define HYDRA_SCLK_OE 0x00000010
30 #define HYDRA_SDAT_OE 0x00000020
31
pdregw(void * data,u32 val)32 static inline void pdregw(void *data, u32 val)
33 {
34 struct Hydra *hydra = (struct Hydra *)data;
35 writel(val, &hydra->CachePD);
36 }
37
pdregr(void * data)38 static inline u32 pdregr(void *data)
39 {
40 struct Hydra *hydra = (struct Hydra *)data;
41 return readl(&hydra->CachePD);
42 }
43
hydra_bit_setscl(void * data,int state)44 static void hydra_bit_setscl(void *data, int state)
45 {
46 u32 val = pdregr(data);
47 if (state)
48 val &= ~HYDRA_SCLK_OE;
49 else {
50 val &= ~HYDRA_SCLK;
51 val |= HYDRA_SCLK_OE;
52 }
53 pdregw(data, val);
54 }
55
hydra_bit_setsda(void * data,int state)56 static void hydra_bit_setsda(void *data, int state)
57 {
58 u32 val = pdregr(data);
59 if (state)
60 val &= ~HYDRA_SDAT_OE;
61 else {
62 val &= ~HYDRA_SDAT;
63 val |= HYDRA_SDAT_OE;
64 }
65 pdregw(data, val);
66 }
67
hydra_bit_getscl(void * data)68 static int hydra_bit_getscl(void *data)
69 {
70 return (pdregr(data) & HYDRA_SCLK) != 0;
71 }
72
hydra_bit_getsda(void * data)73 static int hydra_bit_getsda(void *data)
74 {
75 return (pdregr(data) & HYDRA_SDAT) != 0;
76 }
77
78 /* ------------------------------------------------------------------------ */
79
80 static struct i2c_algo_bit_data hydra_bit_data = {
81 .setsda = hydra_bit_setsda,
82 .setscl = hydra_bit_setscl,
83 .getsda = hydra_bit_getsda,
84 .getscl = hydra_bit_getscl,
85 .udelay = 5,
86 .timeout = HZ
87 };
88
89 static struct i2c_adapter hydra_adap = {
90 .owner = THIS_MODULE,
91 .name = "Hydra i2c",
92 .algo_data = &hydra_bit_data,
93 };
94
95 static const struct pci_device_id hydra_ids[] = {
96 { PCI_DEVICE(PCI_VENDOR_ID_APPLE, PCI_DEVICE_ID_APPLE_HYDRA) },
97 { 0, }
98 };
99
100 MODULE_DEVICE_TABLE (pci, hydra_ids);
101
hydra_probe(struct pci_dev * dev,const struct pci_device_id * id)102 static int hydra_probe(struct pci_dev *dev,
103 const struct pci_device_id *id)
104 {
105 unsigned long base = pci_resource_start(dev, 0);
106 int res;
107
108 if (!request_mem_region(base+offsetof(struct Hydra, CachePD), 4,
109 hydra_adap.name))
110 return -EBUSY;
111
112 hydra_bit_data.data = pci_ioremap_bar(dev, 0);
113 if (hydra_bit_data.data == NULL) {
114 release_mem_region(base+offsetof(struct Hydra, CachePD), 4);
115 return -ENODEV;
116 }
117
118 pdregw(hydra_bit_data.data, 0); /* clear SCLK_OE and SDAT_OE */
119 hydra_adap.dev.parent = &dev->dev;
120 res = i2c_bit_add_bus(&hydra_adap);
121 if (res < 0) {
122 iounmap(hydra_bit_data.data);
123 release_mem_region(base+offsetof(struct Hydra, CachePD), 4);
124 return res;
125 }
126 return 0;
127 }
128
hydra_remove(struct pci_dev * dev)129 static void hydra_remove(struct pci_dev *dev)
130 {
131 pdregw(hydra_bit_data.data, 0); /* clear SCLK_OE and SDAT_OE */
132 i2c_del_adapter(&hydra_adap);
133 iounmap(hydra_bit_data.data);
134 release_mem_region(pci_resource_start(dev, 0)+
135 offsetof(struct Hydra, CachePD), 4);
136 }
137
138
139 static struct pci_driver hydra_driver = {
140 .name = "hydra_smbus",
141 .id_table = hydra_ids,
142 .probe = hydra_probe,
143 .remove = hydra_remove,
144 };
145
146 module_pci_driver(hydra_driver);
147
148 MODULE_AUTHOR("Geert Uytterhoeven <geert@linux-m68k.org>");
149 MODULE_DESCRIPTION("i2c for Apple Hydra Mac I/O");
150 MODULE_LICENSE("GPL");
151