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
32static inline void pdregw(void *data, u32 val)
33{
34	struct Hydra *hydra = (struct Hydra *)data;
35	writel(val, &hydra->CachePD);
36}
37
38static inline u32 pdregr(void *data)
39{
40	struct Hydra *hydra = (struct Hydra *)data;
41	return readl(&hydra->CachePD);
42}
43
44static 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
56static 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
68static int hydra_bit_getscl(void *data)
69{
70	return (pdregr(data) & HYDRA_SCLK) != 0;
71}
72
73static int hydra_bit_getsda(void *data)
74{
75	return (pdregr(data) & HYDRA_SDAT) != 0;
76}
77
78/* ------------------------------------------------------------------------ */
79
80static 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
89static struct i2c_adapter hydra_adap = {
90	.owner		= THIS_MODULE,
91	.name		= "Hydra i2c",
92	.algo_data	= &hydra_bit_data,
93};
94
95static const struct pci_device_id hydra_ids[] = {
96	{ PCI_DEVICE(PCI_VENDOR_ID_APPLE, PCI_DEVICE_ID_APPLE_HYDRA) },
97	{ 0, }
98};
99
100MODULE_DEVICE_TABLE (pci, hydra_ids);
101
102static 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
129static 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
139static struct pci_driver hydra_driver = {
140	.name		= "hydra_smbus",
141	.id_table	= hydra_ids,
142	.probe		= hydra_probe,
143	.remove		= hydra_remove,
144};
145
146module_pci_driver(hydra_driver);
147
148MODULE_AUTHOR("Geert Uytterhoeven <geert@linux-m68k.org>");
149MODULE_DESCRIPTION("i2c for Apple Hydra Mac I/O");
150MODULE_LICENSE("GPL");
151