2 * Copyright © 2006-2007 Intel Corporation
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
21 * DEALINGS IN THE SOFTWARE.
24 * Eric Anholt <eric@anholt.net>
27 * Copyright (c) 2006 Dave Airlie <airlied@linux.ie>
28 * Jesse Barnes <jesse.barnes@intel.com>
31 #include <linux/i2c.h>
32 #include <linux/i2c-id.h>
33 #include <linux/i2c-algo-bit.h>
36 #include "intel_drv.h"
39 #define I2C_HW_B_INTELFB 0x010021; /* intel framebuffer driver */
42 * Intel GPIO access functions
45 #define I2C_RISEFALL_TIME 20
47 static int get_clock(void *data)
49 struct intel_i2c_chan *chan = data;
50 struct drm_psb_private *dev_priv = chan->drm_dev->dev_private;
53 val = PSB_RVDC32(chan->reg);
54 return ((val & GPIO_CLOCK_VAL_IN) != 0);
57 static int get_data(void *data)
59 struct intel_i2c_chan *chan = data;
60 struct drm_psb_private *dev_priv = chan->drm_dev->dev_private;
63 val = PSB_RVDC32(chan->reg);
64 return ((val & GPIO_DATA_VAL_IN) != 0);
67 static void set_clock(void *data, int state_high)
69 struct intel_i2c_chan *chan = data;
70 struct drm_psb_private *dev_priv = chan->drm_dev->dev_private;
71 uint32_t reserved = 0, clock_bits;
73 /* On most chips, these bits must be preserved in software. */
74 reserved = PSB_RVDC32(chan->reg) & (GPIO_DATA_PULLUP_DISABLE |
75 GPIO_CLOCK_PULLUP_DISABLE);
78 clock_bits = GPIO_CLOCK_DIR_IN | GPIO_CLOCK_DIR_MASK;
80 clock_bits = GPIO_CLOCK_DIR_OUT | GPIO_CLOCK_DIR_MASK |
82 PSB_WVDC32(reserved | clock_bits, chan->reg);
83 udelay(I2C_RISEFALL_TIME); /* wait for the line to change state */
86 static void set_data(void *data, int state_high)
88 struct intel_i2c_chan *chan = data;
89 struct drm_psb_private *dev_priv = chan->drm_dev->dev_private;
90 uint32_t reserved = 0, data_bits;
92 /* On most chips, these bits must be preserved in software. */
93 reserved = PSB_RVDC32(chan->reg) & (GPIO_DATA_PULLUP_DISABLE |
94 GPIO_CLOCK_PULLUP_DISABLE);
97 data_bits = GPIO_DATA_DIR_IN | GPIO_DATA_DIR_MASK;
99 data_bits = GPIO_DATA_DIR_OUT | GPIO_DATA_DIR_MASK |
102 PSB_WVDC32(data_bits, chan->reg);
103 udelay(I2C_RISEFALL_TIME); /* wait for the line to change state */
107 * intel_i2c_create - instantiate an Intel i2c bus using the specified GPIO reg
109 * @output: driver specific output device
110 * @reg: GPIO reg to use
111 * @name: name for this bus
113 * Creates and registers a new i2c bus with the Linux i2c layer, for use
114 * in output probing and control (e.g. DDC or SDVO control functions).
116 * Possible values for @reg include:
125 * see PRM for details on how these different busses are used.
127 struct intel_i2c_chan *intel_i2c_create(struct drm_device *dev,
128 const uint32_t reg, const char *name)
130 struct intel_i2c_chan *chan;
132 chan = kzalloc(sizeof(struct intel_i2c_chan), GFP_KERNEL);
138 snprintf(chan->adapter.name, I2C_NAME_SIZE, "intel drm %s", name);
139 chan->adapter.owner = THIS_MODULE;
140 chan->adapter.id = I2C_HW_B_INTELFB;
141 chan->adapter.algo_data = &chan->algo;
142 chan->adapter.dev.parent = &dev->pdev->dev;
143 chan->algo.setsda = set_data;
144 chan->algo.setscl = set_clock;
145 chan->algo.getsda = get_data;
146 chan->algo.getscl = get_clock;
147 chan->algo.udelay = 20;
148 chan->algo.timeout = usecs_to_jiffies(2200);
149 chan->algo.data = chan;
151 i2c_set_adapdata(&chan->adapter, chan);
153 if (i2c_bit_add_bus(&chan->adapter))
156 /* JJJ: raise SCL and SDA? */
169 * intel_i2c_destroy - unregister and free i2c bus resources
170 * @output: channel to free
172 * Unregister the adapter from the i2c layer, then free the structure.
174 void intel_i2c_destroy(struct intel_i2c_chan *chan)
179 i2c_del_adapter(&chan->adapter);