drivers/video/i810/i810-i2c.c: fix i2c bus handling
[~shefty/rdma-dev.git] / drivers / video / i810 / i810-i2c.c
1  /*-*- linux-c -*-
2  *  linux/drivers/video/i810-i2c.c -- Intel 810/815 I2C support
3  *
4  *      Copyright (C) 2004 Antonino Daplas<adaplas@pol.net>
5  *      All Rights Reserved
6  *
7  *  This file is subject to the terms and conditions of the GNU General Public
8  *  License. See the file COPYING in the main directory of this archive for
9  *  more details.
10  */
11 #include <linux/module.h>
12 #include <linux/kernel.h>
13 #include <linux/delay.h>
14 #include <linux/gfp.h>
15 #include <linux/pci.h>
16 #include <linux/fb.h>
17 #include "i810.h"
18 #include "i810_regs.h"
19 #include "i810_main.h"
20 #include "../edid.h"
21
22 /* bit locations in the registers */
23 #define SCL_DIR_MASK            0x0001
24 #define SCL_DIR                 0x0002
25 #define SCL_VAL_MASK            0x0004
26 #define SCL_VAL_OUT             0x0008
27 #define SCL_VAL_IN              0x0010
28 #define SDA_DIR_MASK            0x0100
29 #define SDA_DIR                 0x0200
30 #define SDA_VAL_MASK            0x0400
31 #define SDA_VAL_OUT             0x0800
32 #define SDA_VAL_IN              0x1000
33
34 #define DEBUG  /* define this for verbose EDID parsing output */
35
36 #ifdef DEBUG
37 #define DPRINTK(fmt, args...) printk(fmt,## args)
38 #else
39 #define DPRINTK(fmt, args...)
40 #endif
41
42 static void i810i2c_setscl(void *data, int state)
43 {
44         struct i810fb_i2c_chan    *chan = data;
45         struct i810fb_par         *par = chan->par;
46         u8                        __iomem *mmio = par->mmio_start_virtual;
47
48         if (state)
49                 i810_writel(mmio, chan->ddc_base, SCL_DIR_MASK | SCL_VAL_MASK);
50         else
51                 i810_writel(mmio, chan->ddc_base, SCL_DIR | SCL_DIR_MASK | SCL_VAL_MASK);
52         i810_readl(mmio, chan->ddc_base);       /* flush posted write */
53 }
54
55 static void i810i2c_setsda(void *data, int state)
56 {
57         struct i810fb_i2c_chan    *chan = data;
58         struct i810fb_par         *par = chan->par;
59         u8                        __iomem *mmio = par->mmio_start_virtual;
60
61         if (state)
62                 i810_writel(mmio, chan->ddc_base, SDA_DIR_MASK | SDA_VAL_MASK);
63         else
64                 i810_writel(mmio, chan->ddc_base, SDA_DIR | SDA_DIR_MASK | SDA_VAL_MASK);
65         i810_readl(mmio, chan->ddc_base);       /* flush posted write */
66 }
67
68 static int i810i2c_getscl(void *data)
69 {
70         struct i810fb_i2c_chan    *chan = data;
71         struct i810fb_par         *par = chan->par;
72         u8                        __iomem *mmio = par->mmio_start_virtual;
73
74         i810_writel(mmio, chan->ddc_base, SCL_DIR_MASK);
75         i810_writel(mmio, chan->ddc_base, 0);
76         return ((i810_readl(mmio, chan->ddc_base) & SCL_VAL_IN) != 0);
77 }
78
79 static int i810i2c_getsda(void *data)
80 {
81         struct i810fb_i2c_chan    *chan = data;
82         struct i810fb_par         *par = chan->par;
83         u8                        __iomem *mmio = par->mmio_start_virtual;
84
85         i810_writel(mmio, chan->ddc_base, SDA_DIR_MASK);
86         i810_writel(mmio, chan->ddc_base, 0);
87         return ((i810_readl(mmio, chan->ddc_base) & SDA_VAL_IN) != 0);
88 }
89
90 static int i810_setup_i2c_bus(struct i810fb_i2c_chan *chan, const char *name)
91 {
92         int rc;
93
94         strcpy(chan->adapter.name, name);
95         chan->adapter.owner             = THIS_MODULE;
96         chan->adapter.algo_data         = &chan->algo;
97         chan->adapter.dev.parent        = &chan->par->dev->dev;
98         chan->algo.setsda               = i810i2c_setsda;
99         chan->algo.setscl               = i810i2c_setscl;
100         chan->algo.getsda               = i810i2c_getsda;
101         chan->algo.getscl               = i810i2c_getscl;
102         chan->algo.udelay               = 10;
103         chan->algo.timeout              = (HZ/2);
104         chan->algo.data                 = chan;
105
106         i2c_set_adapdata(&chan->adapter, chan);
107
108         /* Raise SCL and SDA */
109         chan->algo.setsda(chan, 1);
110         chan->algo.setscl(chan, 1);
111         udelay(20);
112
113         rc = i2c_bit_add_bus(&chan->adapter);
114
115         if (rc == 0)
116                 dev_dbg(&chan->par->dev->dev, "I2C bus %s registered.\n",name);
117         else {
118                 dev_warn(&chan->par->dev->dev, "Failed to register I2C bus "
119                          "%s.\n", name);
120                 chan->par = NULL;
121         }
122
123         return rc;
124 }
125
126 void i810_create_i2c_busses(struct i810fb_par *par)
127 {
128         par->chan[0].par        = par;
129         par->chan[1].par        = par;
130         par->chan[2].par        = par;
131
132         par->chan[0].ddc_base = GPIOA;
133         i810_setup_i2c_bus(&par->chan[0], "I810-DDC");
134         par->chan[1].ddc_base = GPIOB;
135         i810_setup_i2c_bus(&par->chan[1], "I810-I2C");
136         par->chan[2].ddc_base = GPIOC;
137         i810_setup_i2c_bus(&par->chan[2], "I810-GPIOC");
138 }
139
140 void i810_delete_i2c_busses(struct i810fb_par *par)
141 {
142         if (par->chan[0].par)
143                 i2c_del_adapter(&par->chan[0].adapter);
144         par->chan[0].par = NULL;
145
146         if (par->chan[1].par)
147                 i2c_del_adapter(&par->chan[1].adapter);
148         par->chan[1].par = NULL;
149
150         if (par->chan[2].par)
151                 i2c_del_adapter(&par->chan[2].adapter);
152         par->chan[2].par = NULL;
153 }
154
155 int i810_probe_i2c_connector(struct fb_info *info, u8 **out_edid, int conn)
156 {
157         struct i810fb_par *par = info->par;
158         u8 *edid = NULL;
159
160         DPRINTK("i810-i2c: Probe DDC%i Bus\n", conn+1);
161         if (conn < par->ddc_num) {
162                 edid = fb_ddc_read(&par->chan[conn].adapter);
163         } else {
164                 const u8 *e = fb_firmware_edid(info->device);
165
166                 if (e != NULL) {
167                         DPRINTK("i810-i2c: Getting EDID from BIOS\n");
168                         edid = kmemdup(e, EDID_LENGTH, GFP_KERNEL);
169                 }
170         }
171
172         *out_edid = edid;
173
174         return (edid) ? 0 : 1;
175 }