| 27,8 → 27,8 |
|---|
| #include <linux/errno.h> |
| #include <linux/sched.h> |
| #include <linux/i2c.h> |
| #include <drm/drm_dp_helper.h> |
| #include <drm/drmP.h> |
| #include <drm/drm_dp_helper.h> |
| |
| /** |
| * DOC: dp helpers |
| 39,198 → 39,6 |
|---|
| * blocks, ... |
| */ |
| |
| /* 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; |
| } |
| |
| /** |
| * i2c_dp_aux_add_bus() - register an i2c adapter using the aux ch helper |
| * @adapter: i2c adapter to register |
| * |
| * This registers an i2c adapter that uses dp aux channel as it's underlaying |
| * transport. The driver needs to fill out the &i2c_algo_dp_aux_data structure |
| * and store it in the algo_data member of the @adapter argument. This will be |
| * used by the i2c over dp aux algorithm to drive the hardware. |
| * |
| * RETURNS: |
| * 0 on success, -ERRNO on failure. |
| * |
| * IMPORTANT: |
| * This interface is deprecated, please switch to the new dp aux helpers and |
| * drm_dp_aux_register(). |
| */ |
| 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); |
| |
| /* Helpers for DP link training */ |
| static u8 dp_link_status(const u8 link_status[DP_LINK_STATUS_SIZE], int r) |
| { |
| 378,10 → 186,11 |
|---|
| |
| /* |
| * The specification doesn't give any recommendation on how often to |
| * retry native transactions, so retry 7 times like for I2C-over-AUX |
| * transactions. |
| * retry native transactions. We used to retry 7 times like for |
| * aux i2c transactions but real world devices this wasn't |
| * sufficient, bump to 32 which makes Dell 4k monitors happier. |
| */ |
| for (retry = 0; retry < 7; retry++) { |
| for (retry = 0; retry < 32; retry++) { |
| |
| mutex_lock(&aux->hw_mutex); |
| err = aux->transfer(aux, &msg); |