1 /* 2 * Copyright 2012 Red Hat Inc. 3 * 4 * Permission is hereby granted, free of charge, to any person obtaining a 5 * copy of this software and associated documentation files (the 6 * "Software"), to deal in the Software without restriction, including 7 * without limitation the rights to use, copy, modify, merge, publish, 8 * distribute, sub license, and/or sell copies of the Software, and to 9 * permit persons to whom the Software is furnished to do so, subject to 10 * the following conditions: 11 * 12 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 13 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 14 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL 15 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, 16 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR 17 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE 18 * USE OR OTHER DEALINGS IN THE SOFTWARE. 19 * 20 * The above copyright notice and this permission notice (including the 21 * next paragraph) shall be included in all copies or substantial portions 22 * of the Software. 23 * 24 */ 25 /* 26 * Authors: Dave Airlie <airlied@redhat.com> 27 */ 28 29 #include <linux/i2c-algo-bit.h> 30 #include <linux/i2c.h> 31 #include <linux/pci.h> 32 33 #include <drm/drm_managed.h> 34 35 #include "mgag200_ddc.h" 36 #include "mgag200_drv.h" 37 38 struct mgag200_ddc { 39 struct mga_device *mdev; 40 41 int data; 42 int clock; 43 44 struct i2c_algo_bit_data bit; 45 struct i2c_adapter adapter; 46 }; 47 48 static int mga_i2c_read_gpio(struct mga_device *mdev) 49 { 50 WREG8(DAC_INDEX, MGA1064_GEN_IO_DATA); 51 return RREG8(DAC_DATA); 52 } 53 54 static void mga_i2c_set_gpio(struct mga_device *mdev, int mask, int val) 55 { 56 int tmp; 57 58 WREG8(DAC_INDEX, MGA1064_GEN_IO_CTL); 59 tmp = (RREG8(DAC_DATA) & mask) | val; 60 WREG_DAC(MGA1064_GEN_IO_CTL, tmp); 61 WREG_DAC(MGA1064_GEN_IO_DATA, 0); 62 } 63 64 static inline void mga_i2c_set(struct mga_device *mdev, int mask, int state) 65 { 66 if (state) 67 state = 0; 68 else 69 state = mask; 70 mga_i2c_set_gpio(mdev, ~mask, state); 71 } 72 73 static void mgag200_ddc_algo_bit_data_setsda(void *data, int state) 74 { 75 struct mgag200_ddc *ddc = data; 76 77 mga_i2c_set(ddc->mdev, ddc->data, state); 78 } 79 80 static void mgag200_ddc_algo_bit_data_setscl(void *data, int state) 81 { 82 struct mgag200_ddc *ddc = data; 83 84 mga_i2c_set(ddc->mdev, ddc->clock, state); 85 } 86 87 static int mgag200_ddc_algo_bit_data_getsda(void *data) 88 { 89 struct mgag200_ddc *ddc = data; 90 91 return (mga_i2c_read_gpio(ddc->mdev) & ddc->data) ? 1 : 0; 92 } 93 94 static int mgag200_ddc_algo_bit_data_getscl(void *data) 95 { 96 struct mgag200_ddc *ddc = data; 97 98 return (mga_i2c_read_gpio(ddc->mdev) & ddc->clock) ? 1 : 0; 99 } 100 101 static int mgag200_ddc_algo_bit_data_pre_xfer(struct i2c_adapter *adapter) 102 { 103 struct mgag200_ddc *ddc = i2c_get_adapdata(adapter); 104 struct mga_device *mdev = ddc->mdev; 105 106 /* 107 * Protect access to I/O registers from concurrent modesetting 108 * by acquiring the I/O-register lock. 109 */ 110 mutex_lock(&mdev->rmmio_lock); 111 112 return 0; 113 } 114 115 static void mgag200_ddc_algo_bit_data_post_xfer(struct i2c_adapter *adapter) 116 { 117 struct mgag200_ddc *ddc = i2c_get_adapdata(adapter); 118 struct mga_device *mdev = ddc->mdev; 119 120 mutex_unlock(&mdev->rmmio_lock); 121 } 122 123 static void mgag200_ddc_release(struct drm_device *dev, void *res) 124 { 125 struct mgag200_ddc *ddc = res; 126 127 i2c_del_adapter(&ddc->adapter); 128 } 129 130 struct i2c_adapter *mgag200_ddc_create(struct mga_device *mdev) 131 { 132 struct drm_device *dev = &mdev->base; 133 const struct mgag200_device_info *info = mdev->info; 134 struct mgag200_ddc *ddc; 135 struct i2c_algo_bit_data *bit; 136 struct i2c_adapter *adapter; 137 int ret; 138 139 ddc = drmm_kzalloc(dev, sizeof(*ddc), GFP_KERNEL); 140 if (!ddc) 141 return ERR_PTR(-ENOMEM); 142 143 WREG_DAC(MGA1064_GEN_IO_CTL2, 1); 144 WREG_DAC(MGA1064_GEN_IO_DATA, 0xff); 145 WREG_DAC(MGA1064_GEN_IO_CTL, 0); 146 147 ddc->mdev = mdev; 148 ddc->data = BIT(info->i2c.data_bit); 149 ddc->clock = BIT(info->i2c.clock_bit); 150 151 bit = &ddc->bit; 152 bit->data = ddc; 153 bit->setsda = mgag200_ddc_algo_bit_data_setsda; 154 bit->setscl = mgag200_ddc_algo_bit_data_setscl; 155 bit->getsda = mgag200_ddc_algo_bit_data_getsda; 156 bit->getscl = mgag200_ddc_algo_bit_data_getscl; 157 bit->pre_xfer = mgag200_ddc_algo_bit_data_pre_xfer; 158 bit->post_xfer = mgag200_ddc_algo_bit_data_post_xfer; 159 bit->udelay = 10; 160 bit->timeout = usecs_to_jiffies(2200); 161 162 adapter = &ddc->adapter; 163 adapter->owner = THIS_MODULE; 164 adapter->algo_data = bit; 165 adapter->dev.parent = dev->dev; 166 snprintf(adapter->name, sizeof(adapter->name), "Matrox DDC bus"); 167 i2c_set_adapdata(adapter, ddc); 168 169 ret = i2c_bit_add_bus(adapter); 170 if (ret) 171 return ERR_PTR(ret); 172 173 ret = drmm_add_action_or_reset(dev, mgag200_ddc_release, ddc); 174 if (ret) 175 return ERR_PTR(ret); 176 177 return adapter; 178 } 179