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"
41 * Intel GPIO access functions
44 #define I2C_RISEFALL_TIME 20
46 static int get_clock(void *data)
48 struct intel_i2c_chan *chan = data;
49 struct drm_i915_private *dev_priv = chan->drm_dev->dev_private;
52 val = I915_READ(chan->reg);
53 return ((val & GPIO_CLOCK_VAL_IN) != 0);
56 static int get_data(void *data)
58 struct intel_i2c_chan *chan = data;
59 struct drm_i915_private *dev_priv = chan->drm_dev->dev_private;
62 val = I915_READ(chan->reg);
63 return ((val & GPIO_DATA_VAL_IN) != 0);
66 static void set_clock(void *data, int state_high)
68 struct intel_i2c_chan *chan = data;
69 struct drm_device *dev = chan->drm_dev;
70 struct drm_i915_private *dev_priv = chan->drm_dev->dev_private;
71 u32 reserved = 0, clock_bits;
73 /* On most chips, these bits must be preserved in software. */
74 if (!IS_I830(dev) && !IS_845G(dev))
75 reserved = I915_READ(chan->reg) & (GPIO_DATA_PULLUP_DISABLE |
76 GPIO_CLOCK_PULLUP_DISABLE);
79 clock_bits = GPIO_CLOCK_DIR_IN | GPIO_CLOCK_DIR_MASK;
81 clock_bits = GPIO_CLOCK_DIR_OUT | GPIO_CLOCK_DIR_MASK |
83 I915_WRITE(chan->reg, reserved | clock_bits);
84 udelay(I2C_RISEFALL_TIME); /* wait for the line to change state */
87 static void set_data(void *data, int state_high)
89 struct intel_i2c_chan *chan = data;
90 struct drm_device *dev = chan->drm_dev;
91 struct drm_i915_private *dev_priv = chan->drm_dev->dev_private;
92 u32 reserved = 0, data_bits;
94 /* On most chips, these bits must be preserved in software. */
95 if (!IS_I830(dev) && !IS_845G(dev))
96 reserved = I915_READ(chan->reg) & (GPIO_DATA_PULLUP_DISABLE |
97 GPIO_CLOCK_PULLUP_DISABLE);
100 data_bits = GPIO_DATA_DIR_IN | GPIO_DATA_DIR_MASK;
102 data_bits = GPIO_DATA_DIR_OUT | GPIO_DATA_DIR_MASK |
105 I915_WRITE(chan->reg, reserved | data_bits);
106 udelay(I2C_RISEFALL_TIME); /* wait for the line to change state */
110 * intel_i2c_create - instantiate an Intel i2c bus using the specified GPIO reg
112 * @output: driver specific output device
113 * @reg: GPIO reg to use
114 * @name: name for this bus
116 * Creates and registers a new i2c bus with the Linux i2c layer, for use
117 * in output probing and control (e.g. DDC or SDVO control functions).
119 * Possible values for @reg include:
128 * see PRM for details on how these different busses are used.
130 struct intel_i2c_chan *intel_i2c_create(struct drm_device *dev, const u32 reg,
133 struct intel_i2c_chan *chan;
135 chan = kzalloc(sizeof(struct intel_i2c_chan), GFP_KERNEL);
141 snprintf(chan->adapter.name, I2C_NAME_SIZE, "intel drm %s", name);
142 chan->adapter.owner = THIS_MODULE;
143 #ifndef I2C_HW_B_INTELFB
144 #define I2C_HW_B_INTELFB I2C_HW_B_I810
146 chan->adapter.id = I2C_HW_B_INTELFB;
147 chan->adapter.algo_data = &chan->algo;
148 chan->adapter.dev.parent = &dev->pdev->dev;
149 chan->algo.setsda = set_data;
150 chan->algo.setscl = set_clock;
151 chan->algo.getsda = get_data;
152 chan->algo.getscl = get_clock;
153 chan->algo.udelay = 20;
154 chan->algo.timeout = usecs_to_jiffies(2200);
155 chan->algo.data = chan;
157 i2c_set_adapdata(&chan->adapter, chan);
159 if(i2c_bit_add_bus(&chan->adapter))
162 /* JJJ: raise SCL and SDA? */
175 * intel_i2c_destroy - unregister and free i2c bus resources
176 * @output: channel to free
178 * Unregister the adapter from the i2c layer, then free the structure.
180 void intel_i2c_destroy(struct intel_i2c_chan *chan)
185 i2c_del_adapter(&chan->adapter);