diff options
Diffstat (limited to 'drivers/gpu/drm/drm_dp_i2c_helper.c')
| -rw-r--r-- | drivers/gpu/drm/drm_dp_i2c_helper.c | 208 |
1 files changed, 0 insertions, 208 deletions
diff --git a/drivers/gpu/drm/drm_dp_i2c_helper.c b/drivers/gpu/drm/drm_dp_i2c_helper.c deleted file mode 100644 index f7eba0a0973..00000000000 --- a/drivers/gpu/drm/drm_dp_i2c_helper.c +++ /dev/null @@ -1,208 +0,0 @@ -/* - * Copyright © 2009 Keith Packard - * - * Permission to use, copy, modify, distribute, and sell this software and its - * documentation for any purpose is hereby granted without fee, provided that - * the above copyright notice appear in all copies and that both that copyright - * notice and this permission notice appear in supporting documentation, and - * that the name of the copyright holders not be used in advertising or - * publicity pertaining to distribution of the software without specific, - * written prior permission. The copyright holders make no representations - * about the suitability of this software for any purpose. It is provided "as - * is" without express or implied warranty. - * - * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, - * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO - * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR - * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, - * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER - * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE - * OF THIS SOFTWARE. - */ - -#include <linux/kernel.h> -#include <linux/module.h> -#include <linux/delay.h> -#include <linux/init.h> -#include <linux/errno.h> -#include <linux/sched.h> -#include <linux/i2c.h> -#include "drm_dp_helper.h" -#include "drmP.h" - -/* Run a single AUX_CH I2C transaction, writing/reading data as necessary */ -static int -i2c_algo_dp_aux_transaction(struct i2c_adapter *adapter, int mode, - uint8_t write_byte, uint8_t *read_byte) -{ - struct i2c_algo_dp_aux_data *algo_data = adapter->algo_data; - int ret; - - ret = (*algo_data->aux_ch)(adapter, mode, - write_byte, read_byte); - return ret; -} - -/* - * I2C over AUX CH - */ - -/* - * Send the address. If the I2C link is running, this 'restarts' - * the connection with the new address, this is used for doing - * a write followed by a read (as needed for DDC) - */ -static int -i2c_algo_dp_aux_address(struct i2c_adapter *adapter, u16 address, bool reading) -{ - struct i2c_algo_dp_aux_data *algo_data = adapter->algo_data; - int mode = MODE_I2C_START; - int ret; - - if (reading) - mode |= MODE_I2C_READ; - else - mode |= MODE_I2C_WRITE; - algo_data->address = address; - algo_data->running = true; - ret = i2c_algo_dp_aux_transaction(adapter, mode, 0, NULL); - return ret; -} - -/* - * Stop the I2C transaction. This closes out the link, sending - * a bare address packet with the MOT bit turned off - */ -static void -i2c_algo_dp_aux_stop(struct i2c_adapter *adapter, bool reading) -{ - struct i2c_algo_dp_aux_data *algo_data = adapter->algo_data; - int mode = MODE_I2C_STOP; - - if (reading) - mode |= MODE_I2C_READ; - else - mode |= MODE_I2C_WRITE; - if (algo_data->running) { - (void) i2c_algo_dp_aux_transaction(adapter, mode, 0, NULL); - algo_data->running = false; - } -} - -/* - * Write a single byte to the current I2C address, the - * the I2C link must be running or this returns -EIO - */ -static int -i2c_algo_dp_aux_put_byte(struct i2c_adapter *adapter, u8 byte) -{ - struct i2c_algo_dp_aux_data *algo_data = adapter->algo_data; - int ret; - - if (!algo_data->running) - return -EIO; - - ret = i2c_algo_dp_aux_transaction(adapter, MODE_I2C_WRITE, byte, NULL); - return ret; -} - -/* - * Read a single byte from the current I2C address, the - * I2C link must be running or this returns -EIO - */ -static int -i2c_algo_dp_aux_get_byte(struct i2c_adapter *adapter, u8 *byte_ret) -{ - struct i2c_algo_dp_aux_data *algo_data = adapter->algo_data; - int ret; - - if (!algo_data->running) - return -EIO; - - ret = i2c_algo_dp_aux_transaction(adapter, MODE_I2C_READ, 0, byte_ret); - return ret; -} - -static int -i2c_algo_dp_aux_xfer(struct i2c_adapter *adapter, - struct i2c_msg *msgs, - int num) -{ - int ret = 0; - bool reading = false; - int m; - int b; - - for (m = 0; m < num; m++) { - u16 len = msgs[m].len; - u8 *buf = msgs[m].buf; - reading = (msgs[m].flags & I2C_M_RD) != 0; - ret = i2c_algo_dp_aux_address(adapter, msgs[m].addr, reading); - if (ret < 0) - break; - if (reading) { - for (b = 0; b < len; b++) { - ret = i2c_algo_dp_aux_get_byte(adapter, &buf[b]); - if (ret < 0) - break; - } - } else { - for (b = 0; b < len; b++) { - ret = i2c_algo_dp_aux_put_byte(adapter, buf[b]); - if (ret < 0) - break; - } - } - if (ret < 0) - break; - } - if (ret >= 0) - ret = num; - i2c_algo_dp_aux_stop(adapter, reading); - DRM_DEBUG_KMS("dp_aux_xfer return %d\n", ret); - return ret; -} - -static u32 -i2c_algo_dp_aux_functionality(struct i2c_adapter *adapter) -{ - return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | - I2C_FUNC_SMBUS_READ_BLOCK_DATA | - I2C_FUNC_SMBUS_BLOCK_PROC_CALL | - I2C_FUNC_10BIT_ADDR; -} - -static const struct i2c_algorithm i2c_dp_aux_algo = { - .master_xfer = i2c_algo_dp_aux_xfer, - .functionality = i2c_algo_dp_aux_functionality, -}; - -static void -i2c_dp_aux_reset_bus(struct i2c_adapter *adapter) -{ - (void) i2c_algo_dp_aux_address(adapter, 0, false); - (void) i2c_algo_dp_aux_stop(adapter, false); - -} - -static int -i2c_dp_aux_prepare_bus(struct i2c_adapter *adapter) -{ - adapter->algo = &i2c_dp_aux_algo; - adapter->retries = 3; - i2c_dp_aux_reset_bus(adapter); - return 0; -} - -int -i2c_dp_aux_add_bus(struct i2c_adapter *adapter) -{ - int error; - - error = i2c_dp_aux_prepare_bus(adapter); - if (error) - return error; - error = i2c_add_adapter(adapter); - return error; -} -EXPORT_SYMBOL(i2c_dp_aux_add_bus); |