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_drv.h" 37 38 static int mga_i2c_read_gpio(struct mga_device *mdev) 39 { 40 WREG8(DAC_INDEX, MGA1064_GEN_IO_DATA); 41 return RREG8(DAC_DATA); 42 } 43 44 static void mga_i2c_set_gpio(struct mga_device *mdev, int mask, int val) 45 { 46 int tmp; 47 48 WREG8(DAC_INDEX, MGA1064_GEN_IO_CTL); 49 tmp = (RREG8(DAC_DATA) & mask) | val; 50 WREG_DAC(MGA1064_GEN_IO_CTL, tmp); 51 WREG_DAC(MGA1064_GEN_IO_DATA, 0); 52 } 53 54 static inline void mga_i2c_set(struct mga_device *mdev, int mask, int state) 55 { 56 if (state) 57 state = 0; 58 else 59 state = mask; 60 mga_i2c_set_gpio(mdev, ~mask, state); 61 } 62 63 static void mga_gpio_setsda(void *data, int state) 64 { 65 struct mga_i2c_chan *i2c = data; 66 struct mga_device *mdev = to_mga_device(i2c->dev); 67 mga_i2c_set(mdev, i2c->data, state); 68 } 69 70 static void mga_gpio_setscl(void *data, int state) 71 { 72 struct mga_i2c_chan *i2c = data; 73 struct mga_device *mdev = to_mga_device(i2c->dev); 74 mga_i2c_set(mdev, i2c->clock, state); 75 } 76 77 static int mga_gpio_getsda(void *data) 78 { 79 struct mga_i2c_chan *i2c = data; 80 struct mga_device *mdev = to_mga_device(i2c->dev); 81 return (mga_i2c_read_gpio(mdev) & i2c->data) ? 1 : 0; 82 } 83 84 static int mga_gpio_getscl(void *data) 85 { 86 struct mga_i2c_chan *i2c = data; 87 struct mga_device *mdev = to_mga_device(i2c->dev); 88 return (mga_i2c_read_gpio(mdev) & i2c->clock) ? 1 : 0; 89 } 90 91 static void mgag200_i2c_release(struct drm_device *dev, void *res) 92 { 93 struct mga_i2c_chan *i2c = res; 94 95 i2c_del_adapter(&i2c->adapter); 96 } 97 98 int mgag200_i2c_init(struct mga_device *mdev, struct mga_i2c_chan *i2c) 99 { 100 struct drm_device *dev = &mdev->base; 101 const struct mgag200_device_info *info = mdev->info; 102 int ret; 103 104 WREG_DAC(MGA1064_GEN_IO_CTL2, 1); 105 WREG_DAC(MGA1064_GEN_IO_DATA, 0xff); 106 WREG_DAC(MGA1064_GEN_IO_CTL, 0); 107 108 i2c->data = BIT(info->i2c.data_bit); 109 i2c->clock = BIT(info->i2c.clock_bit); 110 i2c->adapter.owner = THIS_MODULE; 111 i2c->adapter.class = I2C_CLASS_DDC; 112 i2c->adapter.dev.parent = dev->dev; 113 i2c->dev = dev; 114 i2c_set_adapdata(&i2c->adapter, i2c); 115 snprintf(i2c->adapter.name, sizeof(i2c->adapter.name), "mga i2c"); 116 117 i2c->adapter.algo_data = &i2c->bit; 118 119 i2c->bit.udelay = 10; 120 i2c->bit.timeout = usecs_to_jiffies(2200); 121 i2c->bit.data = i2c; 122 i2c->bit.setsda = mga_gpio_setsda; 123 i2c->bit.setscl = mga_gpio_setscl; 124 i2c->bit.getsda = mga_gpio_getsda; 125 i2c->bit.getscl = mga_gpio_getscl; 126 127 ret = i2c_bit_add_bus(&i2c->adapter); 128 if (ret) 129 return ret; 130 131 return drmm_add_action_or_reset(dev, mgag200_i2c_release, i2c); 132 } 133