Jesse Barnes | 79e5394 | 2008-11-07 14:24:08 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2006 Dave Airlie <airlied@linux.ie> |
| 3 | * Copyright © 2006-2008 Intel Corporation |
| 4 | * Jesse Barnes <jesse.barnes@intel.com> |
| 5 | * |
| 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: |
| 12 | * |
| 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 |
| 15 | * Software. |
| 16 | * |
| 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. |
| 24 | * |
| 25 | * Authors: |
| 26 | * Eric Anholt <eric@anholt.net> |
| 27 | */ |
| 28 | #include <linux/i2c.h> |
| 29 | #include <linux/i2c-id.h> |
| 30 | #include <linux/i2c-algo-bit.h> |
| 31 | #include "drmP.h" |
| 32 | #include "drm.h" |
| 33 | #include "intel_drv.h" |
| 34 | #include "i915_drm.h" |
| 35 | #include "i915_drv.h" |
| 36 | |
Shaohua Li | 0ba0e9e | 2009-04-07 11:02:28 +0800 | [diff] [blame] | 37 | void intel_i2c_quirk_set(struct drm_device *dev, bool enable) |
| 38 | { |
| 39 | struct drm_i915_private *dev_priv = dev->dev_private; |
| 40 | |
| 41 | /* When using bit bashing for I2C, this bit needs to be set to 1 */ |
| 42 | if (!IS_IGD(dev)) |
| 43 | return; |
| 44 | if (enable) |
| 45 | I915_WRITE(CG_2D_DIS, |
| 46 | I915_READ(CG_2D_DIS) | DPCUNIT_CLOCK_GATE_DISABLE); |
| 47 | else |
| 48 | I915_WRITE(CG_2D_DIS, |
| 49 | I915_READ(CG_2D_DIS) & (~DPCUNIT_CLOCK_GATE_DISABLE)); |
| 50 | } |
| 51 | |
Jesse Barnes | 79e5394 | 2008-11-07 14:24:08 -0800 | [diff] [blame] | 52 | /* |
| 53 | * Intel GPIO access functions |
| 54 | */ |
| 55 | |
| 56 | #define I2C_RISEFALL_TIME 20 |
| 57 | |
| 58 | static int get_clock(void *data) |
| 59 | { |
| 60 | struct intel_i2c_chan *chan = data; |
| 61 | struct drm_i915_private *dev_priv = chan->drm_dev->dev_private; |
| 62 | u32 val; |
| 63 | |
| 64 | val = I915_READ(chan->reg); |
| 65 | return ((val & GPIO_CLOCK_VAL_IN) != 0); |
| 66 | } |
| 67 | |
| 68 | static int get_data(void *data) |
| 69 | { |
| 70 | struct intel_i2c_chan *chan = data; |
| 71 | struct drm_i915_private *dev_priv = chan->drm_dev->dev_private; |
| 72 | u32 val; |
| 73 | |
| 74 | val = I915_READ(chan->reg); |
| 75 | return ((val & GPIO_DATA_VAL_IN) != 0); |
| 76 | } |
| 77 | |
| 78 | static void set_clock(void *data, int state_high) |
| 79 | { |
| 80 | struct intel_i2c_chan *chan = data; |
| 81 | struct drm_device *dev = chan->drm_dev; |
| 82 | struct drm_i915_private *dev_priv = chan->drm_dev->dev_private; |
| 83 | u32 reserved = 0, clock_bits; |
| 84 | |
| 85 | /* On most chips, these bits must be preserved in software. */ |
| 86 | if (!IS_I830(dev) && !IS_845G(dev)) |
| 87 | reserved = I915_READ(chan->reg) & (GPIO_DATA_PULLUP_DISABLE | |
| 88 | GPIO_CLOCK_PULLUP_DISABLE); |
| 89 | |
| 90 | if (state_high) |
| 91 | clock_bits = GPIO_CLOCK_DIR_IN | GPIO_CLOCK_DIR_MASK; |
| 92 | else |
| 93 | clock_bits = GPIO_CLOCK_DIR_OUT | GPIO_CLOCK_DIR_MASK | |
| 94 | GPIO_CLOCK_VAL_MASK; |
| 95 | I915_WRITE(chan->reg, reserved | clock_bits); |
| 96 | udelay(I2C_RISEFALL_TIME); /* wait for the line to change state */ |
| 97 | } |
| 98 | |
| 99 | static void set_data(void *data, int state_high) |
| 100 | { |
| 101 | struct intel_i2c_chan *chan = data; |
| 102 | struct drm_device *dev = chan->drm_dev; |
| 103 | struct drm_i915_private *dev_priv = chan->drm_dev->dev_private; |
| 104 | u32 reserved = 0, data_bits; |
| 105 | |
| 106 | /* On most chips, these bits must be preserved in software. */ |
| 107 | if (!IS_I830(dev) && !IS_845G(dev)) |
| 108 | reserved = I915_READ(chan->reg) & (GPIO_DATA_PULLUP_DISABLE | |
| 109 | GPIO_CLOCK_PULLUP_DISABLE); |
| 110 | |
| 111 | if (state_high) |
| 112 | data_bits = GPIO_DATA_DIR_IN | GPIO_DATA_DIR_MASK; |
| 113 | else |
| 114 | data_bits = GPIO_DATA_DIR_OUT | GPIO_DATA_DIR_MASK | |
| 115 | GPIO_DATA_VAL_MASK; |
| 116 | |
| 117 | I915_WRITE(chan->reg, reserved | data_bits); |
| 118 | udelay(I2C_RISEFALL_TIME); /* wait for the line to change state */ |
| 119 | } |
| 120 | |
| 121 | /** |
| 122 | * intel_i2c_create - instantiate an Intel i2c bus using the specified GPIO reg |
| 123 | * @dev: DRM device |
| 124 | * @output: driver specific output device |
| 125 | * @reg: GPIO reg to use |
| 126 | * @name: name for this bus |
| 127 | * |
| 128 | * Creates and registers a new i2c bus with the Linux i2c layer, for use |
| 129 | * in output probing and control (e.g. DDC or SDVO control functions). |
| 130 | * |
| 131 | * Possible values for @reg include: |
| 132 | * %GPIOA |
| 133 | * %GPIOB |
| 134 | * %GPIOC |
| 135 | * %GPIOD |
| 136 | * %GPIOE |
| 137 | * %GPIOF |
| 138 | * %GPIOG |
| 139 | * %GPIOH |
| 140 | * see PRM for details on how these different busses are used. |
| 141 | */ |
| 142 | struct intel_i2c_chan *intel_i2c_create(struct drm_device *dev, const u32 reg, |
| 143 | const char *name) |
| 144 | { |
| 145 | struct intel_i2c_chan *chan; |
| 146 | |
| 147 | chan = kzalloc(sizeof(struct intel_i2c_chan), GFP_KERNEL); |
| 148 | if (!chan) |
| 149 | goto out_free; |
| 150 | |
| 151 | chan->drm_dev = dev; |
| 152 | chan->reg = reg; |
| 153 | snprintf(chan->adapter.name, I2C_NAME_SIZE, "intel drm %s", name); |
| 154 | chan->adapter.owner = THIS_MODULE; |
Jesse Barnes | 79e5394 | 2008-11-07 14:24:08 -0800 | [diff] [blame] | 155 | chan->adapter.algo_data = &chan->algo; |
| 156 | chan->adapter.dev.parent = &dev->pdev->dev; |
| 157 | chan->algo.setsda = set_data; |
| 158 | chan->algo.setscl = set_clock; |
| 159 | chan->algo.getsda = get_data; |
| 160 | chan->algo.getscl = get_clock; |
| 161 | chan->algo.udelay = 20; |
| 162 | chan->algo.timeout = usecs_to_jiffies(2200); |
| 163 | chan->algo.data = chan; |
| 164 | |
| 165 | i2c_set_adapdata(&chan->adapter, chan); |
| 166 | |
| 167 | if(i2c_bit_add_bus(&chan->adapter)) |
| 168 | goto out_free; |
| 169 | |
| 170 | /* JJJ: raise SCL and SDA? */ |
Shaohua Li | 0ba0e9e | 2009-04-07 11:02:28 +0800 | [diff] [blame] | 171 | intel_i2c_quirk_set(dev, true); |
Jesse Barnes | 79e5394 | 2008-11-07 14:24:08 -0800 | [diff] [blame] | 172 | set_data(chan, 1); |
| 173 | set_clock(chan, 1); |
Shaohua Li | 0ba0e9e | 2009-04-07 11:02:28 +0800 | [diff] [blame] | 174 | intel_i2c_quirk_set(dev, false); |
Jesse Barnes | 79e5394 | 2008-11-07 14:24:08 -0800 | [diff] [blame] | 175 | udelay(20); |
| 176 | |
| 177 | return chan; |
| 178 | |
| 179 | out_free: |
| 180 | kfree(chan); |
| 181 | return NULL; |
| 182 | } |
| 183 | |
| 184 | /** |
| 185 | * intel_i2c_destroy - unregister and free i2c bus resources |
| 186 | * @output: channel to free |
| 187 | * |
| 188 | * Unregister the adapter from the i2c layer, then free the structure. |
| 189 | */ |
| 190 | void intel_i2c_destroy(struct intel_i2c_chan *chan) |
| 191 | { |
| 192 | if (!chan) |
| 193 | return; |
| 194 | |
| 195 | i2c_del_adapter(&chan->adapter); |
| 196 | kfree(chan); |
| 197 | } |