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/slab.h> 30#include <linux/i2c-id.h> 31#include <linux/i2c-algo-bit.h> 32#include "drmP.h" 33#include "drm.h" 34#include "intel_drv.h" 35#include "i915_drm.h" 36#include "i915_drv.h" 37 38void intel_i2c_quirk_set(struct drm_device *dev, bool enable) 39{ 40 struct drm_i915_private *dev_priv = dev->dev_private; 41 42 /* When using bit bashing for I2C, this bit needs to be set to 1 */ 43 if (!IS_PINEVIEW(dev)) 44 return; 45 if (enable) 46 I915_WRITE(DSPCLK_GATE_D, 47 I915_READ(DSPCLK_GATE_D) | DPCUNIT_CLOCK_GATE_DISABLE); 48 else 49 I915_WRITE(DSPCLK_GATE_D, 50 I915_READ(DSPCLK_GATE_D) & (~DPCUNIT_CLOCK_GATE_DISABLE)); 51} 52 53/* 54 * Intel GPIO access functions 55 */ 56 57#define I2C_RISEFALL_TIME 20 58 59static int get_clock(void *data) 60{ 61 struct intel_i2c_chan *chan = data; 62 struct drm_i915_private *dev_priv = chan->drm_dev->dev_private; 63 u32 val; 64 65 val = I915_READ(chan->reg); 66 return ((val & GPIO_CLOCK_VAL_IN) != 0); 67} 68 69static int get_data(void *data) 70{ 71 struct intel_i2c_chan *chan = data; 72 struct drm_i915_private *dev_priv = chan->drm_dev->dev_private; 73 u32 val; 74 75 val = I915_READ(chan->reg); 76 return ((val & GPIO_DATA_VAL_IN) != 0); 77} 78 79static void set_clock(void *data, int state_high) 80{ 81 struct intel_i2c_chan *chan = data; 82 struct drm_device *dev = chan->drm_dev; 83 struct drm_i915_private *dev_priv = chan->drm_dev->dev_private; 84 u32 reserved = 0, clock_bits; 85 86 /* On most chips, these bits must be preserved in software. */ 87 if (!IS_I830(dev) && !IS_845G(dev)) 88 reserved = I915_READ(chan->reg) & (GPIO_DATA_PULLUP_DISABLE | 89 GPIO_CLOCK_PULLUP_DISABLE); 90 91 if (state_high) 92 clock_bits = GPIO_CLOCK_DIR_IN | GPIO_CLOCK_DIR_MASK; 93 else 94 clock_bits = GPIO_CLOCK_DIR_OUT | GPIO_CLOCK_DIR_MASK | 95 GPIO_CLOCK_VAL_MASK; 96 I915_WRITE(chan->reg, reserved | clock_bits); 97 udelay(I2C_RISEFALL_TIME); /* wait for the line to change state */ 98} 99 100static void set_data(void *data, int state_high) 101{ 102 struct intel_i2c_chan *chan = data; 103 struct drm_device *dev = chan->drm_dev; 104 struct drm_i915_private *dev_priv = chan->drm_dev->dev_private; 105 u32 reserved = 0, data_bits; 106 107 /* On most chips, these bits must be preserved in software. */ 108 if (!IS_I830(dev) && !IS_845G(dev)) 109 reserved = I915_READ(chan->reg) & (GPIO_DATA_PULLUP_DISABLE | 110 GPIO_CLOCK_PULLUP_DISABLE); 111 112 if (state_high) 113 data_bits = GPIO_DATA_DIR_IN | GPIO_DATA_DIR_MASK; 114 else 115 data_bits = GPIO_DATA_DIR_OUT | GPIO_DATA_DIR_MASK | 116 GPIO_DATA_VAL_MASK; 117 118 I915_WRITE(chan->reg, reserved | data_bits); 119 udelay(I2C_RISEFALL_TIME); /* wait for the line to change state */ 120} 121 122/* Clears the GMBUS setup. Our driver doesn't make use of the GMBUS I2C 123 * engine, but if the BIOS leaves it enabled, then that can break our use 124 * of the bit-banging I2C interfaces. This is notably the case with the 125 * Mac Mini in EFI mode. 126 */ 127void 128intel_i2c_reset_gmbus(struct drm_device *dev) 129{ 130 struct drm_i915_private *dev_priv = dev->dev_private; 131 132 if (HAS_PCH_SPLIT(dev)) { 133 I915_WRITE(PCH_GMBUS0, 0); 134 } else { 135 I915_WRITE(GMBUS0, 0); 136 } 137} 138 139/** 140 * intel_i2c_create - instantiate an Intel i2c bus using the specified GPIO reg 141 * @dev: DRM device 142 * @output: driver specific output device 143 * @reg: GPIO reg to use 144 * @name: name for this bus 145 * @slave_addr: slave address (if fixed) 146 * 147 * Creates and registers a new i2c bus with the Linux i2c layer, for use 148 * in output probing and control (e.g. DDC or SDVO control functions). 149 * 150 * Possible values for @reg include: 151 * %GPIOA 152 * %GPIOB 153 * %GPIOC 154 * %GPIOD 155 * %GPIOE 156 * %GPIOF 157 * %GPIOG 158 * %GPIOH 159 * see PRM for details on how these different busses are used. 160 */ 161struct i2c_adapter *intel_i2c_create(struct drm_device *dev, const u32 reg, 162 const char *name) 163{ 164 struct intel_i2c_chan *chan; 165 166 chan = kzalloc(sizeof(struct intel_i2c_chan), GFP_KERNEL); 167 if (!chan) 168 goto out_free; 169 170 chan->drm_dev = dev; 171 chan->reg = reg; 172 snprintf(chan->adapter.name, I2C_NAME_SIZE, "intel drm %s", name); 173 chan->adapter.owner = THIS_MODULE; 174 chan->adapter.algo_data = &chan->algo; 175 chan->adapter.dev.parent = &dev->pdev->dev; 176 chan->algo.setsda = set_data; 177 chan->algo.setscl = set_clock; 178 chan->algo.getsda = get_data; 179 chan->algo.getscl = get_clock; 180 chan->algo.udelay = 20; 181 chan->algo.timeout = usecs_to_jiffies(2200); 182 chan->algo.data = chan; 183 184 i2c_set_adapdata(&chan->adapter, chan); 185 186 if(i2c_bit_add_bus(&chan->adapter)) 187 goto out_free; 188 189 intel_i2c_reset_gmbus(dev); 190 191 /* JJJ: raise SCL and SDA? */ 192 intel_i2c_quirk_set(dev, true); 193 set_data(chan, 1); 194 set_clock(chan, 1); 195 intel_i2c_quirk_set(dev, false); 196 udelay(20); 197 198 return &chan->adapter; 199 200out_free: 201 kfree(chan); 202 return NULL; 203} 204 205/** 206 * intel_i2c_destroy - unregister and free i2c bus resources 207 * @output: channel to free 208 * 209 * Unregister the adapter from the i2c layer, then free the structure. 210 */ 211void intel_i2c_destroy(struct i2c_adapter *adapter) 212{ 213 struct intel_i2c_chan *chan; 214 215 if (!adapter) 216 return; 217 218 chan = container_of(adapter, 219 struct intel_i2c_chan, 220 adapter); 221 i2c_del_adapter(&chan->adapter); 222 kfree(chan); 223} 224