2 * Copyright (c) 2006 Dave Airlie <airlied@linux.ie>
3 * Copyright © 2006-2008 Intel Corporation
4 * Jesse Barnes <jesse.barnes@intel.com>
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the "Software"),
8 * to deal in the Software without restriction, including without limitation
9 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
10 * and/or sell copies of the Software, and to permit persons to whom the
11 * Software is furnished to do so, subject to the following conditions:
13 * The above copyright notice and this permission notice (including the next
14 * paragraph) shall be included in all copies or substantial portions of the
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
22 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
23 * DEALINGS IN THE SOFTWARE.
26 * Eric Anholt <eric@anholt.net>
28 #include <linux/i2c.h>
29 #include <linux/slab.h>
30 #include <linux/i2c-id.h>
31 #include <linux/i2c-algo-bit.h>
34 #include "intel_drv.h"
38 void intel_i2c_quirk_set(struct drm_device *dev, bool enable)
40 struct drm_i915_private *dev_priv = dev->dev_private;
43 /* When using bit bashing for I2C, this bit needs to be set to 1 */
44 if (!IS_PINEVIEW(dev))
47 val = I915_READ(DSPCLK_GATE_D);
49 val |= DPCUNIT_CLOCK_GATE_DISABLE;
51 val &= ~DPCUNIT_CLOCK_GATE_DISABLE;
52 I915_WRITE(DSPCLK_GATE_D, val);
56 * Intel GPIO access functions
59 #define I2C_RISEFALL_TIME 20
61 static int get_clock(void *data)
63 struct intel_i2c_chan *chan = data;
64 struct drm_i915_private *dev_priv = chan->drm_dev->dev_private;
65 return (I915_READ(chan->reg) & GPIO_CLOCK_VAL_IN) != 0;
68 static int get_data(void *data)
70 struct intel_i2c_chan *chan = data;
71 struct drm_i915_private *dev_priv = chan->drm_dev->dev_private;
72 return (I915_READ(chan->reg) & GPIO_DATA_VAL_IN) != 0;
75 static void set_clock(void *data, int state_high)
77 struct intel_i2c_chan *chan = data;
78 struct drm_device *dev = chan->drm_dev;
79 struct drm_i915_private *dev_priv = chan->drm_dev->dev_private;
80 u32 reserved = 0, clock_bits;
82 /* On most chips, these bits must be preserved in software. */
83 if (!IS_I830(dev) && !IS_845G(dev))
84 reserved = I915_READ(chan->reg) & (GPIO_DATA_PULLUP_DISABLE |
85 GPIO_CLOCK_PULLUP_DISABLE);
88 clock_bits = GPIO_CLOCK_DIR_IN | GPIO_CLOCK_DIR_MASK;
90 clock_bits = GPIO_CLOCK_DIR_OUT | GPIO_CLOCK_DIR_MASK |
92 I915_WRITE(chan->reg, reserved | clock_bits);
93 POSTING_READ(chan->reg);
96 static void set_data(void *data, int state_high)
98 struct intel_i2c_chan *chan = data;
99 struct drm_device *dev = chan->drm_dev;
100 struct drm_i915_private *dev_priv = chan->drm_dev->dev_private;
101 u32 reserved = 0, data_bits;
103 /* On most chips, these bits must be preserved in software. */
104 if (!IS_I830(dev) && !IS_845G(dev))
105 reserved = I915_READ(chan->reg) & (GPIO_DATA_PULLUP_DISABLE |
106 GPIO_CLOCK_PULLUP_DISABLE);
109 data_bits = GPIO_DATA_DIR_IN | GPIO_DATA_DIR_MASK;
111 data_bits = GPIO_DATA_DIR_OUT | GPIO_DATA_DIR_MASK |
114 I915_WRITE(chan->reg, reserved | data_bits);
115 POSTING_READ(chan->reg);
118 /* Clears the GMBUS setup. Our driver doesn't make use of the GMBUS I2C
119 * engine, but if the BIOS leaves it enabled, then that can break our use
120 * of the bit-banging I2C interfaces. This is notably the case with the
121 * Mac Mini in EFI mode.
124 intel_i2c_reset_gmbus(struct drm_device *dev)
126 struct drm_i915_private *dev_priv = dev->dev_private;
128 if (HAS_PCH_SPLIT(dev))
129 I915_WRITE(PCH_GMBUS0, 0);
131 I915_WRITE(GMBUS0, 0);
135 * intel_i2c_create - instantiate an Intel i2c bus using the specified GPIO reg
137 * @output: driver specific output device
138 * @reg: GPIO reg to use
139 * @name: name for this bus
140 * @slave_addr: slave address (if fixed)
142 * Creates and registers a new i2c bus with the Linux i2c layer, for use
143 * in output probing and control (e.g. DDC or SDVO control functions).
145 * Possible values for @reg include:
154 * see PRM for details on how these different busses are used.
156 struct i2c_adapter *intel_i2c_create(struct drm_device *dev, const u32 reg,
159 struct intel_i2c_chan *chan;
161 chan = kzalloc(sizeof(struct intel_i2c_chan), GFP_KERNEL);
167 snprintf(chan->adapter.name, I2C_NAME_SIZE, "intel drm %s", name);
168 chan->adapter.owner = THIS_MODULE;
169 chan->adapter.algo_data = &chan->algo;
170 chan->adapter.dev.parent = &dev->pdev->dev;
171 chan->algo.setsda = set_data;
172 chan->algo.setscl = set_clock;
173 chan->algo.getsda = get_data;
174 chan->algo.getscl = get_clock;
175 chan->algo.udelay = I2C_RISEFALL_TIME;
176 chan->algo.timeout = usecs_to_jiffies(2200);
177 chan->algo.data = chan;
179 i2c_set_adapdata(&chan->adapter, chan);
181 if(i2c_bit_add_bus(&chan->adapter))
184 intel_i2c_reset_gmbus(dev);
186 /* JJJ: raise SCL and SDA? */
187 intel_i2c_quirk_set(dev, true);
189 udelay(I2C_RISEFALL_TIME);
191 udelay(I2C_RISEFALL_TIME);
192 intel_i2c_quirk_set(dev, false);
194 return &chan->adapter;
202 * intel_i2c_destroy - unregister and free i2c bus resources
203 * @output: channel to free
205 * Unregister the adapter from the i2c layer, then free the structure.
207 void intel_i2c_destroy(struct i2c_adapter *adapter)
209 struct intel_i2c_chan *chan;
214 chan = container_of(adapter,
215 struct intel_i2c_chan,
217 i2c_del_adapter(&chan->adapter);