1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright 1998-2009 VIA Technologies, Inc. All Rights Reserved.
4 * Copyright 2001-2008 S3 Graphics, Inc. All Rights Reserved.
5
6 */
7
8#include <linux/platform_device.h>
9#include <linux/delay.h>
10#include <linux/spinlock.h>
11#include <linux/module.h>
12#include <linux/via-core.h>
13#include <linux/via_i2c.h>
14
15/*
16 * There can only be one set of these, so there's no point in having
17 * them be dynamically allocated...
18 */
19#define VIAFB_NUM_I2C		5
20static struct via_i2c_stuff via_i2c_par[VIAFB_NUM_I2C];
21static struct viafb_dev *i2c_vdev;  /* Passed in from core */
22
23static void via_i2c_setscl(void *data, int state)
24{
25	u8 val;
26	struct via_port_cfg *adap_data = data;
27	unsigned long flags;
28
29	spin_lock_irqsave(&i2c_vdev->reg_lock, flags);
30	val = via_read_reg(adap_data->io_port, adap_data->ioport_index) & 0xF0;
31	if (state)
32		val |= 0x20;
33	else
34		val &= ~0x20;
35	switch (adap_data->type) {
36	case VIA_PORT_I2C:
37		val |= 0x01;
38		break;
39	case VIA_PORT_GPIO:
40		val |= 0x82;
41		break;
42	default:
43		printk(KERN_ERR "viafb_i2c: specify wrong i2c type.\n");
44	}
45	via_write_reg(adap_data->io_port, adap_data->ioport_index, val);
46	spin_unlock_irqrestore(&i2c_vdev->reg_lock, flags);
47}
48
49static int via_i2c_getscl(void *data)
50{
51	struct via_port_cfg *adap_data = data;
52	unsigned long flags;
53	int ret = 0;
54
55	spin_lock_irqsave(&i2c_vdev->reg_lock, flags);
56	if (adap_data->type == VIA_PORT_GPIO)
57		via_write_reg_mask(adap_data->io_port, adap_data->ioport_index,
58			0, 0x80);
59	if (via_read_reg(adap_data->io_port, adap_data->ioport_index) & 0x08)
60		ret = 1;
61	spin_unlock_irqrestore(&i2c_vdev->reg_lock, flags);
62	return ret;
63}
64
65static int via_i2c_getsda(void *data)
66{
67	struct via_port_cfg *adap_data = data;
68	unsigned long flags;
69	int ret = 0;
70
71	spin_lock_irqsave(&i2c_vdev->reg_lock, flags);
72	if (adap_data->type == VIA_PORT_GPIO)
73		via_write_reg_mask(adap_data->io_port, adap_data->ioport_index,
74			0, 0x40);
75	if (via_read_reg(adap_data->io_port, adap_data->ioport_index) & 0x04)
76		ret = 1;
77	spin_unlock_irqrestore(&i2c_vdev->reg_lock, flags);
78	return ret;
79}
80
81static void via_i2c_setsda(void *data, int state)
82{
83	u8 val;
84	struct via_port_cfg *adap_data = data;
85	unsigned long flags;
86
87	spin_lock_irqsave(&i2c_vdev->reg_lock, flags);
88	val = via_read_reg(adap_data->io_port, adap_data->ioport_index) & 0xF0;
89	if (state)
90		val |= 0x10;
91	else
92		val &= ~0x10;
93	switch (adap_data->type) {
94	case VIA_PORT_I2C:
95		val |= 0x01;
96		break;
97	case VIA_PORT_GPIO:
98		val |= 0x42;
99		break;
100	default:
101		printk(KERN_ERR "viafb_i2c: specify wrong i2c type.\n");
102	}
103	via_write_reg(adap_data->io_port, adap_data->ioport_index, val);
104	spin_unlock_irqrestore(&i2c_vdev->reg_lock, flags);
105}
106
107int viafb_i2c_readbyte(u8 adap, u8 slave_addr, u8 index, u8 *pdata)
108{
109	int ret;
110	u8 mm1[] = {0x00};
111	struct i2c_msg msgs[2];
112
113	if (!via_i2c_par[adap].is_active)
114		return -ENODEV;
115	*pdata = 0;
116	msgs[0].flags = 0;
117	msgs[1].flags = I2C_M_RD;
118	msgs[0].addr = msgs[1].addr = slave_addr / 2;
119	mm1[0] = index;
120	msgs[0].len = 1; msgs[1].len = 1;
121	msgs[0].buf = mm1; msgs[1].buf = pdata;
122	ret = i2c_transfer(&via_i2c_par[adap].adapter, msgs, 2);
123	if (ret == 2)
124		ret = 0;
125	else if (ret >= 0)
126		ret = -EIO;
127
128	return ret;
129}
130
131int viafb_i2c_writebyte(u8 adap, u8 slave_addr, u8 index, u8 data)
132{
133	int ret;
134	u8 msg[2] = { index, data };
135	struct i2c_msg msgs;
136
137	if (!via_i2c_par[adap].is_active)
138		return -ENODEV;
139	msgs.flags = 0;
140	msgs.addr = slave_addr / 2;
141	msgs.len = 2;
142	msgs.buf = msg;
143	ret = i2c_transfer(&via_i2c_par[adap].adapter, &msgs, 1);
144	if (ret == 1)
145		ret = 0;
146	else if (ret >= 0)
147		ret = -EIO;
148
149	return ret;
150}
151
152int viafb_i2c_readbytes(u8 adap, u8 slave_addr, u8 index, u8 *buff, int buff_len)
153{
154	int ret;
155	u8 mm1[] = {0x00};
156	struct i2c_msg msgs[2];
157
158	if (!via_i2c_par[adap].is_active)
159		return -ENODEV;
160	msgs[0].flags = 0;
161	msgs[1].flags = I2C_M_RD;
162	msgs[0].addr = msgs[1].addr = slave_addr / 2;
163	mm1[0] = index;
164	msgs[0].len = 1; msgs[1].len = buff_len;
165	msgs[0].buf = mm1; msgs[1].buf = buff;
166	ret = i2c_transfer(&via_i2c_par[adap].adapter, msgs, 2);
167	if (ret == 2)
168		ret = 0;
169	else if (ret >= 0)
170		ret = -EIO;
171
172	return ret;
173}
174
175/*
176 * Allow other viafb subdevices to look up a specific adapter
177 * by port name.
178 */
179struct i2c_adapter *viafb_find_i2c_adapter(enum viafb_i2c_adap which)
180{
181	struct via_i2c_stuff *stuff = &via_i2c_par[which];
182
183	return &stuff->adapter;
184}
185EXPORT_SYMBOL_GPL(viafb_find_i2c_adapter);
186
187
188static int create_i2c_bus(struct i2c_adapter *adapter,
189			  struct i2c_algo_bit_data *algo,
190			  struct via_port_cfg *adap_cfg,
191			  struct pci_dev *pdev)
192{
193	algo->setsda = via_i2c_setsda;
194	algo->setscl = via_i2c_setscl;
195	algo->getsda = via_i2c_getsda;
196	algo->getscl = via_i2c_getscl;
197	algo->udelay = 10;
198	algo->timeout = 2;
199	algo->data = adap_cfg;
200
201	sprintf(adapter->name, "viafb i2c io_port idx 0x%02x",
202		adap_cfg->ioport_index);
203	adapter->owner = THIS_MODULE;
204	adapter->class = I2C_CLASS_DDC;
205	adapter->algo_data = algo;
206	if (pdev)
207		adapter->dev.parent = &pdev->dev;
208	else
209		adapter->dev.parent = NULL;
210	/* i2c_set_adapdata(adapter, adap_cfg); */
211
212	/* Raise SCL and SDA */
213	via_i2c_setsda(adap_cfg, 1);
214	via_i2c_setscl(adap_cfg, 1);
215	udelay(20);
216
217	return i2c_bit_add_bus(adapter);
218}
219
220static int viafb_i2c_probe(struct platform_device *platdev)
221{
222	int i, ret;
223	struct via_port_cfg *configs;
224
225	i2c_vdev = platdev->dev.platform_data;
226	configs = i2c_vdev->port_cfg;
227
228	for (i = 0; i < VIAFB_NUM_PORTS; i++) {
229		struct via_port_cfg *adap_cfg = configs++;
230		struct via_i2c_stuff *i2c_stuff = &via_i2c_par[i];
231
232		i2c_stuff->is_active = 0;
233		if (adap_cfg->type == 0 || adap_cfg->mode != VIA_MODE_I2C)
234			continue;
235		ret = create_i2c_bus(&i2c_stuff->adapter,
236				     &i2c_stuff->algo, adap_cfg,
237				NULL); /* FIXME: PCIDEV */
238		if (ret < 0) {
239			printk(KERN_ERR "viafb: cannot create i2c bus %u:%d\n",
240				i, ret);
241			continue;  /* Still try to make the rest */
242		}
243		i2c_stuff->is_active = 1;
244	}
245
246	return 0;
247}
248
249static void viafb_i2c_remove(struct platform_device *platdev)
250{
251	int i;
252
253	for (i = 0; i < VIAFB_NUM_PORTS; i++) {
254		struct via_i2c_stuff *i2c_stuff = &via_i2c_par[i];
255		/*
256		 * Only remove those entries in the array that we've
257		 * actually used (and thus initialized algo_data)
258		 */
259		if (i2c_stuff->is_active)
260			i2c_del_adapter(&i2c_stuff->adapter);
261	}
262}
263
264static struct platform_driver via_i2c_driver = {
265	.driver = {
266		.name = "viafb-i2c",
267	},
268	.probe = viafb_i2c_probe,
269	.remove_new = viafb_i2c_remove,
270};
271
272int viafb_i2c_init(void)
273{
274	return platform_driver_register(&via_i2c_driver);
275}
276
277void viafb_i2c_exit(void)
278{
279	platform_driver_unregister(&via_i2c_driver);
280}
281