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_device *ast = to_ast_device(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_VGACRI, 0xb7, 0xf1, ujcrb7);
 39		jtemp = ast_get_index_reg_mask(ast, AST_IO_VGACRI, 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_device *ast = to_ast_device(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_VGACRI, 0xb7, 0xf4, ujcrb7);
 55		jtemp = ast_get_index_reg_mask(ast, AST_IO_VGACRI, 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_device *ast = to_ast_device(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_VGACRI, 0xb7, 0x20) >> 5) & 0x01;
 70	do {
 71		val2 = (ast_get_index_reg_mask(ast, AST_IO_VGACRI, 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_VGACRI, 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_device *ast = to_ast_device(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_VGACRI, 0xb7, 0x10) >> 4) & 0x01;
 92	do {
 93		val2 = (ast_get_index_reg_mask(ast, AST_IO_VGACRI, 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_VGACRI, 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.dev.parent = dev->dev;
124	i2c->dev = dev;
125	i2c_set_adapdata(&i2c->adapter, i2c);
126	snprintf(i2c->adapter.name, sizeof(i2c->adapter.name),
127		 "AST i2c bit bus");
128	i2c->adapter.algo_data = &i2c->bit;
129
130	i2c->bit.udelay = 20;
131	i2c->bit.timeout = 2;
132	i2c->bit.data = i2c;
133	i2c->bit.setsda = ast_i2c_setsda;
134	i2c->bit.setscl = ast_i2c_setscl;
135	i2c->bit.getsda = ast_i2c_getsda;
136	i2c->bit.getscl = ast_i2c_getscl;
137	ret = i2c_bit_add_bus(&i2c->adapter);
138	if (ret) {
139		drm_err(dev, "Failed to register bit i2c\n");
140		goto out_kfree;
141	}
142
143	ret = drmm_add_action_or_reset(dev, ast_i2c_release, i2c);
144	if (ret)
145		return NULL;
146	return i2c;
147
148out_kfree:
149	kfree(i2c);
150	return NULL;
151}