diff options
Diffstat (limited to 'drivers/gpu/drm/ast/ast_ddc.c')
| -rw-r--r-- | drivers/gpu/drm/ast/ast_ddc.c | 187 |
1 files changed, 187 insertions, 0 deletions
diff --git a/drivers/gpu/drm/ast/ast_ddc.c b/drivers/gpu/drm/ast/ast_ddc.c new file mode 100644 index 0000000000..29cf5d157f --- /dev/null +++ b/drivers/gpu/drm/ast/ast_ddc.c @@ -0,0 +1,187 @@ +// 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 <linux/i2c-algo-bit.h> +#include <linux/i2c.h> + +#include <drm/drm_managed.h> +#include <drm/drm_print.h> + +#include "ast_ddc.h" +#include "ast_drv.h" + +struct ast_ddc { + struct ast_device *ast; + + struct i2c_algo_bit_data bit; + struct i2c_adapter adapter; +}; + +static void ast_ddc_algo_bit_data_setsda(void *data, int state) +{ + struct ast_ddc *ddc = data; + struct ast_device *ast = ddc->ast; + int i; + u8 ujcrb7, jtemp; + + for (i = 0; i < 0x10000; i++) { + ujcrb7 = ((state & 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_ddc_algo_bit_data_setscl(void *data, int state) +{ + struct ast_ddc *ddc = data; + struct ast_device *ast = ddc->ast; + int i; + u8 ujcrb7, jtemp; + + for (i = 0; i < 0x10000; i++) { + ujcrb7 = ((state & 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_ddc_algo_bit_data_pre_xfer(struct i2c_adapter *adapter) +{ + struct ast_ddc *ddc = i2c_get_adapdata(adapter); + struct ast_device *ast = ddc->ast; + + /* + * Protect access to I/O registers from concurrent modesetting + * by acquiring the I/O-register lock. + */ + mutex_lock(&ast->modeset_lock); + + return 0; +} + +static void ast_ddc_algo_bit_data_post_xfer(struct i2c_adapter *adapter) +{ + struct ast_ddc *ddc = i2c_get_adapdata(adapter); + struct ast_device *ast = ddc->ast; + + mutex_unlock(&ast->modeset_lock); +} + +static int ast_ddc_algo_bit_data_getsda(void *data) +{ + struct ast_ddc *ddc = data; + struct ast_device *ast = ddc->ast; + 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_ddc_algo_bit_data_getscl(void *data) +{ + struct ast_ddc *ddc = data; + struct ast_device *ast = ddc->ast; + 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_ddc_release(struct drm_device *dev, void *res) +{ + struct ast_ddc *ddc = res; + + i2c_del_adapter(&ddc->adapter); +} + +struct i2c_adapter *ast_ddc_create(struct ast_device *ast) +{ + struct drm_device *dev = &ast->base; + struct ast_ddc *ddc; + struct i2c_adapter *adapter; + struct i2c_algo_bit_data *bit; + int ret; + + ddc = drmm_kzalloc(dev, sizeof(*ddc), GFP_KERNEL); + if (!ddc) + return ERR_PTR(-ENOMEM); + ddc->ast = ast; + + bit = &ddc->bit; + bit->data = ddc; + bit->setsda = ast_ddc_algo_bit_data_setsda; + bit->setscl = ast_ddc_algo_bit_data_setscl; + bit->getsda = ast_ddc_algo_bit_data_getsda; + bit->getscl = ast_ddc_algo_bit_data_getscl; + bit->pre_xfer = ast_ddc_algo_bit_data_pre_xfer; + bit->post_xfer = ast_ddc_algo_bit_data_post_xfer; + bit->udelay = 20; + bit->timeout = usecs_to_jiffies(2200); + + adapter = &ddc->adapter; + adapter->owner = THIS_MODULE; + adapter->algo_data = bit; + adapter->dev.parent = dev->dev; + snprintf(adapter->name, sizeof(adapter->name), "AST DDC bus"); + i2c_set_adapdata(adapter, ddc); + + ret = i2c_bit_add_bus(adapter); + if (ret) { + drm_err(dev, "Failed to register bit i2c\n"); + return ERR_PTR(ret); + } + + ret = drmm_add_action_or_reset(dev, ast_ddc_release, ddc); + if (ret) + return ERR_PTR(ret); + + return &ddc->adapter; +} |