ast_i2c.c (4334B)
1// SPDX-License-Identifier: MIT 2/* 3 * Permission is hereby granted, free of charge, to any person obtaining a 4 * copy of this software and associated documentation files (the 5 * "Software"), to deal in the Software without restriction, including 6 * without limitation the rights to use, copy, modify, merge, publish, 7 * distribute, sub license, and/or sell copies of the Software, and to 8 * permit persons to whom the Software is furnished to do so, subject to 9 * the following conditions: 10 * 11 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 12 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 13 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL 14 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, 15 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR 16 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE 17 * USE OR OTHER DEALINGS IN THE SOFTWARE. 18 * 19 * The above copyright notice and this permission notice (including the 20 * next paragraph) shall be included in all copies or substantial portions 21 * of the Software. 22 */ 23 24#include <drm/drm_managed.h> 25#include <drm/drm_print.h> 26 27#include "ast_drv.h" 28 29static void ast_i2c_setsda(void *i2c_priv, int data) 30{ 31 struct ast_i2c_chan *i2c = i2c_priv; 32 struct ast_private *ast = to_ast_private(i2c->dev); 33 int i; 34 u8 ujcrb7, jtemp; 35 36 for (i = 0; i < 0x10000; i++) { 37 ujcrb7 = ((data & 0x01) ? 0 : 1) << 2; 38 ast_set_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xb7, 0xf1, ujcrb7); 39 jtemp = ast_get_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xb7, 0x04); 40 if (ujcrb7 == jtemp) 41 break; 42 } 43} 44 45static void ast_i2c_setscl(void *i2c_priv, int clock) 46{ 47 struct ast_i2c_chan *i2c = i2c_priv; 48 struct ast_private *ast = to_ast_private(i2c->dev); 49 int i; 50 u8 ujcrb7, jtemp; 51 52 for (i = 0; i < 0x10000; i++) { 53 ujcrb7 = ((clock & 0x01) ? 0 : 1); 54 ast_set_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xb7, 0xf4, ujcrb7); 55 jtemp = ast_get_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xb7, 0x01); 56 if (ujcrb7 == jtemp) 57 break; 58 } 59} 60 61static int ast_i2c_getsda(void *i2c_priv) 62{ 63 struct ast_i2c_chan *i2c = i2c_priv; 64 struct ast_private *ast = to_ast_private(i2c->dev); 65 uint32_t val, val2, count, pass; 66 67 count = 0; 68 pass = 0; 69 val = (ast_get_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xb7, 0x20) >> 5) & 0x01; 70 do { 71 val2 = (ast_get_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xb7, 0x20) >> 5) & 0x01; 72 if (val == val2) { 73 pass++; 74 } else { 75 pass = 0; 76 val = (ast_get_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xb7, 0x20) >> 5) & 0x01; 77 } 78 } while ((pass < 5) && (count++ < 0x10000)); 79 80 return val & 1 ? 1 : 0; 81} 82 83static int ast_i2c_getscl(void *i2c_priv) 84{ 85 struct ast_i2c_chan *i2c = i2c_priv; 86 struct ast_private *ast = to_ast_private(i2c->dev); 87 uint32_t val, val2, count, pass; 88 89 count = 0; 90 pass = 0; 91 val = (ast_get_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xb7, 0x10) >> 4) & 0x01; 92 do { 93 val2 = (ast_get_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xb7, 0x10) >> 4) & 0x01; 94 if (val == val2) { 95 pass++; 96 } else { 97 pass = 0; 98 val = (ast_get_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xb7, 0x10) >> 4) & 0x01; 99 } 100 } while ((pass < 5) && (count++ < 0x10000)); 101 102 return val & 1 ? 1 : 0; 103} 104 105static void ast_i2c_release(struct drm_device *dev, void *res) 106{ 107 struct ast_i2c_chan *i2c = res; 108 109 i2c_del_adapter(&i2c->adapter); 110 kfree(i2c); 111} 112 113struct ast_i2c_chan *ast_i2c_create(struct drm_device *dev) 114{ 115 struct ast_i2c_chan *i2c; 116 int ret; 117 118 i2c = kzalloc(sizeof(struct ast_i2c_chan), GFP_KERNEL); 119 if (!i2c) 120 return NULL; 121 122 i2c->adapter.owner = THIS_MODULE; 123 i2c->adapter.class = I2C_CLASS_DDC; 124 i2c->adapter.dev.parent = dev->dev; 125 i2c->dev = dev; 126 i2c_set_adapdata(&i2c->adapter, i2c); 127 snprintf(i2c->adapter.name, sizeof(i2c->adapter.name), 128 "AST i2c bit bus"); 129 i2c->adapter.algo_data = &i2c->bit; 130 131 i2c->bit.udelay = 20; 132 i2c->bit.timeout = 2; 133 i2c->bit.data = i2c; 134 i2c->bit.setsda = ast_i2c_setsda; 135 i2c->bit.setscl = ast_i2c_setscl; 136 i2c->bit.getsda = ast_i2c_getsda; 137 i2c->bit.getscl = ast_i2c_getscl; 138 ret = i2c_bit_add_bus(&i2c->adapter); 139 if (ret) { 140 drm_err(dev, "Failed to register bit i2c\n"); 141 goto out_kfree; 142 } 143 144 ret = drmm_add_action_or_reset(dev, ast_i2c_release, i2c); 145 if (ret) 146 return NULL; 147 return i2c; 148 149out_kfree: 150 kfree(i2c); 151 return NULL; 152}