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/export.h> 30 #include <linux/i2c-algo-bit.h> 31 #include <linux/i2c.h> 32 #include <linux/pci.h> 33 34 #include <drm/drm_managed.h> 35 36 #include "mgag200_ddc.h" 37 #include "mgag200_drv.h" 38 39 struct mgag200_ddc { 40 struct mga_device *mdev; 41 42 int data; 43 int clock; 44 45 struct i2c_algo_bit_data bit; 46 struct i2c_adapter adapter; 47 }; 48 49 static int mga_i2c_read_gpio(struct mga_device *mdev) 50 { 51 WREG8(DAC_INDEX, MGA1064_GEN_IO_DATA); 52 return RREG8(DAC_DATA); 53 } 54 55 static void mga_i2c_set_gpio(struct mga_device *mdev, int mask, int val) 56 { 57 int tmp; 58 59 WREG8(DAC_INDEX, MGA1064_GEN_IO_CTL); 60 tmp = (RREG8(DAC_DATA) & mask) | val; 61 WREG_DAC(MGA1064_GEN_IO_CTL, tmp); 62 WREG_DAC(MGA1064_GEN_IO_DATA, 0); 63 } 64 65 static inline void mga_i2c_set(struct mga_device *mdev, int mask, int state) 66 { 67 if (state) 68 state = 0; 69 else 70 state = mask; 71 mga_i2c_set_gpio(mdev, ~mask, state); 72 } 73 74 static void mgag200_ddc_algo_bit_data_setsda(void *data, int state) 75 { 76 struct mgag200_ddc *ddc = data; 77 78 mga_i2c_set(ddc->mdev, ddc->data, state); 79 } 80 81 static void mgag200_ddc_algo_bit_data_setscl(void *data, int state) 82 { 83 struct mgag200_ddc *ddc = data; 84 85 mga_i2c_set(ddc->mdev, ddc->clock, state); 86 } 87 88 static int mgag200_ddc_algo_bit_data_getsda(void *data) 89 { 90 struct mgag200_ddc *ddc = data; 91 92 return (mga_i2c_read_gpio(ddc->mdev) & ddc->data) ? 1 : 0; 93 } 94 95 static int mgag200_ddc_algo_bit_data_getscl(void *data) 96 { 97 struct mgag200_ddc *ddc = data; 98 99 return (mga_i2c_read_gpio(ddc->mdev) & ddc->clock) ? 1 : 0; 100 } 101 102 static int mgag200_ddc_algo_bit_data_pre_xfer(struct i2c_adapter *adapter) 103 { 104 struct mgag200_ddc *ddc = i2c_get_adapdata(adapter); 105 struct mga_device *mdev = ddc->mdev; 106 107 /* 108 * Protect access to I/O registers from concurrent modesetting 109 * by acquiring the I/O-register lock. 110 */ 111 mutex_lock(&mdev->rmmio_lock); 112 113 return 0; 114 } 115 116 static void mgag200_ddc_algo_bit_data_post_xfer(struct i2c_adapter *adapter) 117 { 118 struct mgag200_ddc *ddc = i2c_get_adapdata(adapter); 119 struct mga_device *mdev = ddc->mdev; 120 121 mutex_unlock(&mdev->rmmio_lock); 122 } 123 124 static void mgag200_ddc_release(struct drm_device *dev, void *res) 125 { 126 struct mgag200_ddc *ddc = res; 127 128 i2c_del_adapter(&ddc->adapter); 129 } 130 131 struct i2c_adapter *mgag200_ddc_create(struct mga_device *mdev) 132 { 133 struct drm_device *dev = &mdev->base; 134 const struct mgag200_device_info *info = mdev->info; 135 struct mgag200_ddc *ddc; 136 struct i2c_algo_bit_data *bit; 137 struct i2c_adapter *adapter; 138 int ret; 139 140 ddc = drmm_kzalloc(dev, sizeof(*ddc), GFP_KERNEL); 141 if (!ddc) 142 return ERR_PTR(-ENOMEM); 143 144 WREG_DAC(MGA1064_GEN_IO_CTL2, 1); 145 WREG_DAC(MGA1064_GEN_IO_DATA, 0xff); 146 WREG_DAC(MGA1064_GEN_IO_CTL, 0); 147 148 ddc->mdev = mdev; 149 ddc->data = BIT(info->i2c.data_bit); 150 ddc->clock = BIT(info->i2c.clock_bit); 151 152 bit = &ddc->bit; 153 bit->data = ddc; 154 bit->setsda = mgag200_ddc_algo_bit_data_setsda; 155 bit->setscl = mgag200_ddc_algo_bit_data_setscl; 156 bit->getsda = mgag200_ddc_algo_bit_data_getsda; 157 bit->getscl = mgag200_ddc_algo_bit_data_getscl; 158 bit->pre_xfer = mgag200_ddc_algo_bit_data_pre_xfer; 159 bit->post_xfer = mgag200_ddc_algo_bit_data_post_xfer; 160 bit->udelay = 10; 161 bit->timeout = usecs_to_jiffies(2200); 162 163 adapter = &ddc->adapter; 164 adapter->owner = THIS_MODULE; 165 adapter->algo_data = bit; 166 adapter->dev.parent = dev->dev; 167 snprintf(adapter->name, sizeof(adapter->name), "Matrox DDC bus"); 168 i2c_set_adapdata(adapter, ddc); 169 170 ret = i2c_bit_add_bus(adapter); 171 if (ret) 172 return ERR_PTR(ret); 173 174 ret = drmm_add_action_or_reset(dev, mgag200_ddc_release, ddc); 175 if (ret) 176 return ERR_PTR(ret); 177 178 return adapter; 179 } 180