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/kernel.h>
27 #include <linux/module.h>
28 #include <linux/pci.h>
29 #include <linux/types.h>
30 #include <linux/i2c.h>
31 #include <linux/i2c-algo-bit.h>
32 #include <linux/init.h>
33 #include <linux/io.h>
34 #include <linux/delay.h>
35
36 #include <drm/drmP.h>
37 #include "psb_drv.h"
38 #include "psb_intel_reg.h"
39
40
41 /*
42 * LPC GPIO based I2C bus for LVDS of Atom E6xx
43 */
44
45 /*-----------------------------------------------------------------------------
46 * LPC Register Offsets. Used for LVDS GPIO Bit Bashing. Registers are part
47 * Atom E6xx [D31:F0]
48 ----------------------------------------------------------------------------*/
49 #define RGEN 0x20
50 #define RGIO 0x24
51 #define RGLVL 0x28
52 #define RGTPE 0x2C
53 #define RGTNE 0x30
54 #define RGGPE 0x34
55 #define RGSMI 0x38
56 #define RGTS 0x3C
57
58 /* The LVDS GPIO clock lines are GPIOSUS[3]
59 * The LVDS GPIO data lines are GPIOSUS[4]
60 */
61 #define GPIO_CLOCK 0x08
62 #define GPIO_DATA 0x10
63
64 #define LPC_READ_REG(chan, r) inl((chan)->reg + (r))
65 #define LPC_WRITE_REG(chan, r, val) outl((val), (chan)->reg + (r))
66
get_clock(void * data)67 static int get_clock(void *data)
68 {
69 struct psb_intel_i2c_chan *chan = data;
70 u32 val, tmp;
71
72 val = LPC_READ_REG(chan, RGIO);
73 val |= GPIO_CLOCK;
74 LPC_WRITE_REG(chan, RGIO, val);
75 tmp = LPC_READ_REG(chan, RGLVL);
76 val = (LPC_READ_REG(chan, RGLVL) & GPIO_CLOCK) ? 1 : 0;
77
78 return val;
79 }
80
get_data(void * data)81 static int get_data(void *data)
82 {
83 struct psb_intel_i2c_chan *chan = data;
84 u32 val, tmp;
85
86 val = LPC_READ_REG(chan, RGIO);
87 val |= GPIO_DATA;
88 LPC_WRITE_REG(chan, RGIO, val);
89 tmp = LPC_READ_REG(chan, RGLVL);
90 val = (LPC_READ_REG(chan, RGLVL) & GPIO_DATA) ? 1 : 0;
91
92 return val;
93 }
94
set_clock(void * data,int state_high)95 static void set_clock(void *data, int state_high)
96 {
97 struct psb_intel_i2c_chan *chan = data;
98 u32 val;
99
100 if (state_high) {
101 val = LPC_READ_REG(chan, RGIO);
102 val |= GPIO_CLOCK;
103 LPC_WRITE_REG(chan, RGIO, val);
104 } else {
105 val = LPC_READ_REG(chan, RGIO);
106 val &= ~GPIO_CLOCK;
107 LPC_WRITE_REG(chan, RGIO, val);
108 val = LPC_READ_REG(chan, RGLVL);
109 val &= ~GPIO_CLOCK;
110 LPC_WRITE_REG(chan, RGLVL, val);
111 }
112 }
113
set_data(void * data,int state_high)114 static void set_data(void *data, int state_high)
115 {
116 struct psb_intel_i2c_chan *chan = data;
117 u32 val;
118
119 if (state_high) {
120 val = LPC_READ_REG(chan, RGIO);
121 val |= GPIO_DATA;
122 LPC_WRITE_REG(chan, RGIO, val);
123 } else {
124 val = LPC_READ_REG(chan, RGIO);
125 val &= ~GPIO_DATA;
126 LPC_WRITE_REG(chan, RGIO, val);
127 val = LPC_READ_REG(chan, RGLVL);
128 val &= ~GPIO_DATA;
129 LPC_WRITE_REG(chan, RGLVL, val);
130 }
131 }
132
oaktrail_lvds_i2c_init(struct drm_encoder * encoder)133 void oaktrail_lvds_i2c_init(struct drm_encoder *encoder)
134 {
135 struct drm_device *dev = encoder->dev;
136 struct gma_encoder *gma_encoder = to_gma_encoder(encoder);
137 struct drm_psb_private *dev_priv = dev->dev_private;
138 struct psb_intel_i2c_chan *chan;
139
140 chan = kzalloc(sizeof(struct psb_intel_i2c_chan), GFP_KERNEL);
141 if (!chan)
142 return;
143
144 chan->drm_dev = dev;
145 chan->reg = dev_priv->lpc_gpio_base;
146 strncpy(chan->adapter.name, "gma500 LPC", I2C_NAME_SIZE - 1);
147 chan->adapter.owner = THIS_MODULE;
148 chan->adapter.algo_data = &chan->algo;
149 chan->adapter.dev.parent = &dev->pdev->dev;
150 chan->algo.setsda = set_data;
151 chan->algo.setscl = set_clock;
152 chan->algo.getsda = get_data;
153 chan->algo.getscl = get_clock;
154 chan->algo.udelay = 100;
155 chan->algo.timeout = usecs_to_jiffies(2200);
156 chan->algo.data = chan;
157
158 i2c_set_adapdata(&chan->adapter, chan);
159
160 set_data(chan, 1);
161 set_clock(chan, 1);
162 udelay(50);
163
164 if (i2c_bit_add_bus(&chan->adapter)) {
165 kfree(chan);
166 return;
167 }
168
169 gma_encoder->ddc_bus = chan;
170 }
171