ast_i2c.c
// SPDX-License-Identifier: MIT
/*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sub license, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
* THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
* OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
* USE OR OTHER DEALINGS IN THE SOFTWARE.
*
* The above copyright notice and this permission notice (including the
* next paragraph) shall be included in all copies or substantial portions
* of the Software.
*/
#include <drm/drm_managed.h>
#include <drm/drm_print.h>
#include "ast_drv.h"
static void ast_i2c_setsda(void *i2c_priv, int data)
{
struct ast_i2c_chan *i2c = i2c_priv;
struct ast_device *ast = to_ast_device(i2c->dev);
int i;
u8 ujcrb7, jtemp;
for (i = 0; i < 0x10000; i++) {
ujcrb7 = ((data & 0x01) ? 0 : 1) << 2;
ast_set_index_reg_mask(ast, AST_IO_VGACRI, 0xb7, 0xf1, ujcrb7);
jtemp = ast_get_index_reg_mask(ast, AST_IO_VGACRI, 0xb7, 0x04);
if (ujcrb7 == jtemp)
break;
}
}
static void ast_i2c_setscl(void *i2c_priv, int clock)
{
struct ast_i2c_chan *i2c = i2c_priv;
struct ast_device *ast = to_ast_device(i2c->dev);
int i;
u8 ujcrb7, jtemp;
for (i = 0; i < 0x10000; i++) {
ujcrb7 = ((clock & 0x01) ? 0 : 1);
ast_set_index_reg_mask(ast, AST_IO_VGACRI, 0xb7, 0xf4, ujcrb7);
jtemp = ast_get_index_reg_mask(ast, AST_IO_VGACRI, 0xb7, 0x01);
if (ujcrb7 == jtemp)
break;
}
}
static int ast_i2c_getsda(void *i2c_priv)
{
struct ast_i2c_chan *i2c = i2c_priv;
struct ast_device *ast = to_ast_device(i2c->dev);
uint32_t val, val2, count, pass;
count = 0;
pass = 0;
val = (ast_get_index_reg_mask(ast, AST_IO_VGACRI, 0xb7, 0x20) >> 5) & 0x01;
do {
val2 = (ast_get_index_reg_mask(ast, AST_IO_VGACRI, 0xb7, 0x20) >> 5) & 0x01;
if (val == val2) {
pass++;
} else {
pass = 0;
val = (ast_get_index_reg_mask(ast, AST_IO_VGACRI, 0xb7, 0x20) >> 5) & 0x01;
}
} while ((pass < 5) && (count++ < 0x10000));
return val & 1 ? 1 : 0;
}
static int ast_i2c_getscl(void *i2c_priv)
{
struct ast_i2c_chan *i2c = i2c_priv;
struct ast_device *ast = to_ast_device(i2c->dev);
uint32_t val, val2, count, pass;
count = 0;
pass = 0;
val = (ast_get_index_reg_mask(ast, AST_IO_VGACRI, 0xb7, 0x10) >> 4) & 0x01;
do {
val2 = (ast_get_index_reg_mask(ast, AST_IO_VGACRI, 0xb7, 0x10) >> 4) & 0x01;
if (val == val2) {
pass++;
} else {
pass = 0;
val = (ast_get_index_reg_mask(ast, AST_IO_VGACRI, 0xb7, 0x10) >> 4) & 0x01;
}
} while ((pass < 5) && (count++ < 0x10000));
return val & 1 ? 1 : 0;
}
static void ast_i2c_release(struct drm_device *dev, void *res)
{
struct ast_i2c_chan *i2c = res;
i2c_del_adapter(&i2c->adapter);
kfree(i2c);
}
struct ast_i2c_chan *ast_i2c_create(struct drm_device *dev)
{
struct ast_i2c_chan *i2c;
int ret;
i2c = kzalloc(sizeof(struct ast_i2c_chan), GFP_KERNEL);
if (!i2c)
return NULL;
i2c->adapter.owner = THIS_MODULE;
i2c->adapter.dev.parent = dev->dev;
i2c->dev = dev;
i2c_set_adapdata(&i2c->adapter, i2c);
snprintf(i2c->adapter.name, sizeof(i2c->adapter.name),
"AST i2c bit bus");
i2c->adapter.algo_data = &i2c->bit;
i2c->bit.udelay = 20;
i2c->bit.timeout = 2;
i2c->bit.data = i2c;
i2c->bit.setsda = ast_i2c_setsda;
i2c->bit.setscl = ast_i2c_setscl;
i2c->bit.getsda = ast_i2c_getsda;
i2c->bit.getscl = ast_i2c_getscl;
ret = i2c_bit_add_bus(&i2c->adapter);
if (ret) {
drm_err(dev, "Failed to register bit i2c\n");
goto out_kfree;
}
ret = drmm_add_action_or_reset(dev, ast_i2c_release, i2c);
if (ret)
return NULL;
return i2c;
out_kfree:
kfree(i2c);
return NULL;
}