1 /*
2 * Copyright (c) 2002-2010, Intel Corporation.
3 * Copyright (c) 2014 ATRON electronic GmbH
4 * Author: Jan Safrata <jan.nikitenko@gmail.com>
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
19 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22 * THE SOFTWARE.
23 *
24 */
25
26 #include <linux/delay.h>
27 #include <linux/i2c-algo-bit.h>
28 #include <linux/i2c.h>
29 #include <linux/init.h>
30 #include <linux/io.h>
31 #include <linux/kernel.h>
32 #include <linux/module.h>
33 #include <linux/pci.h>
34 #include <linux/types.h>
35
36 #include "psb_drv.h"
37 #include "psb_intel_reg.h"
38
39
40 /*
41 * LPC GPIO based I2C bus for LVDS of Atom E6xx
42 */
43
44 /*-----------------------------------------------------------------------------
45 * LPC Register Offsets. Used for LVDS GPIO Bit Bashing. Registers are part
46 * Atom E6xx [D31:F0]
47 ----------------------------------------------------------------------------*/
48 #define RGEN 0x20
49 #define RGIO 0x24
50 #define RGLVL 0x28
51 #define RGTPE 0x2C
52 #define RGTNE 0x30
53 #define RGGPE 0x34
54 #define RGSMI 0x38
55 #define RGTS 0x3C
56
57 /* The LVDS GPIO clock lines are GPIOSUS[3]
58 * The LVDS GPIO data lines are GPIOSUS[4]
59 */
60 #define GPIO_CLOCK 0x08
61 #define GPIO_DATA 0x10
62
63 #define LPC_READ_REG(chan, r) inl((chan)->reg + (r))
64 #define LPC_WRITE_REG(chan, r, val) outl((val), (chan)->reg + (r))
65
get_clock(void * data)66 static int get_clock(void *data)
67 {
68 struct gma_i2c_chan *chan = data;
69 u32 val;
70
71 val = LPC_READ_REG(chan, RGIO);
72 val |= GPIO_CLOCK;
73 LPC_WRITE_REG(chan, RGIO, val);
74 LPC_READ_REG(chan, RGLVL);
75 val = (LPC_READ_REG(chan, RGLVL) & GPIO_CLOCK) ? 1 : 0;
76
77 return val;
78 }
79
get_data(void * data)80 static int get_data(void *data)
81 {
82 struct gma_i2c_chan *chan = data;
83 u32 val;
84
85 val = LPC_READ_REG(chan, RGIO);
86 val |= GPIO_DATA;
87 LPC_WRITE_REG(chan, RGIO, val);
88 LPC_READ_REG(chan, RGLVL);
89 val = (LPC_READ_REG(chan, RGLVL) & GPIO_DATA) ? 1 : 0;
90
91 return val;
92 }
93
set_clock(void * data,int state_high)94 static void set_clock(void *data, int state_high)
95 {
96 struct gma_i2c_chan *chan = data;
97 u32 val;
98
99 if (state_high) {
100 val = LPC_READ_REG(chan, RGIO);
101 val |= GPIO_CLOCK;
102 LPC_WRITE_REG(chan, RGIO, val);
103 } else {
104 val = LPC_READ_REG(chan, RGIO);
105 val &= ~GPIO_CLOCK;
106 LPC_WRITE_REG(chan, RGIO, val);
107 val = LPC_READ_REG(chan, RGLVL);
108 val &= ~GPIO_CLOCK;
109 LPC_WRITE_REG(chan, RGLVL, val);
110 }
111 }
112
set_data(void * data,int state_high)113 static void set_data(void *data, int state_high)
114 {
115 struct gma_i2c_chan *chan = data;
116 u32 val;
117
118 if (state_high) {
119 val = LPC_READ_REG(chan, RGIO);
120 val |= GPIO_DATA;
121 LPC_WRITE_REG(chan, RGIO, val);
122 } else {
123 val = LPC_READ_REG(chan, RGIO);
124 val &= ~GPIO_DATA;
125 LPC_WRITE_REG(chan, RGIO, val);
126 val = LPC_READ_REG(chan, RGLVL);
127 val &= ~GPIO_DATA;
128 LPC_WRITE_REG(chan, RGLVL, val);
129 }
130 }
131
oaktrail_lvds_i2c_init(struct drm_device * dev)132 struct gma_i2c_chan *oaktrail_lvds_i2c_init(struct drm_device *dev)
133 {
134 struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
135 struct gma_i2c_chan *chan;
136 int ret;
137
138 chan = kzalloc(sizeof(struct gma_i2c_chan), GFP_KERNEL);
139 if (!chan)
140 return ERR_PTR(-ENOMEM);
141
142 chan->drm_dev = dev;
143 chan->reg = dev_priv->lpc_gpio_base;
144 strncpy(chan->base.name, "gma500 LPC", I2C_NAME_SIZE - 1);
145 chan->base.owner = THIS_MODULE;
146 chan->base.algo_data = &chan->algo;
147 chan->base.dev.parent = dev->dev;
148 chan->algo.setsda = set_data;
149 chan->algo.setscl = set_clock;
150 chan->algo.getsda = get_data;
151 chan->algo.getscl = get_clock;
152 chan->algo.udelay = 100;
153 chan->algo.timeout = usecs_to_jiffies(2200);
154 chan->algo.data = chan;
155
156 i2c_set_adapdata(&chan->base, chan);
157
158 set_data(chan, 1);
159 set_clock(chan, 1);
160 udelay(50);
161
162 ret = i2c_bit_add_bus(&chan->base);
163 if (ret < 0) {
164 kfree(chan);
165 return ERR_PTR(ret);
166 }
167
168 return chan;
169 }
170