diff options
Diffstat (limited to 'drivers/gpu/drm/drm_dp_helper.c')
| -rw-r--r-- | drivers/gpu/drm/drm_dp_helper.c | 80 |
1 files changed, 53 insertions, 27 deletions
diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index 27671489477d..08e33b8b13a4 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -206,13 +206,17 @@ i2c_dp_aux_prepare_bus(struct i2c_adapter *adapter) * i2c_dp_aux_add_bus() - register an i2c adapter using the aux ch helper * @adapter: i2c adapter to register * - * This registers an i2c adapater that uses dp aux channel as it's underlaying + * 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) @@ -378,7 +382,10 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request, * transactions. */ for (retry = 0; retry < 7; retry++) { + + mutex_lock(&aux->hw_mutex); err = aux->transfer(aux, &msg); + mutex_unlock(&aux->hw_mutex); if (err < 0) { if (err == -EBUSY) continue; @@ -577,7 +584,9 @@ static u32 drm_dp_i2c_functionality(struct i2c_adapter *adapter) /* * Transfer a single I2C-over-AUX message and handle various error conditions, - * retrying the transaction as appropriate. + * retrying the transaction as appropriate. It is assumed that the + * aux->transfer function does not modify anything in the msg other than the + * reply field. */ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) { @@ -590,7 +599,9 @@ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) * before giving up the AUX transaction. */ for (retry = 0; retry < 7; retry++) { + mutex_lock(&aux->hw_mutex); err = aux->transfer(aux, msg); + mutex_unlock(&aux->hw_mutex); if (err < 0) { if (err == -EBUSY) continue; @@ -665,11 +676,26 @@ static int drm_dp_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, { struct drm_dp_aux *aux = adapter->algo_data; unsigned int i, j; + struct drm_dp_aux_msg msg; + int err = 0; - for (i = 0; i < num; i++) { - struct drm_dp_aux_msg msg; - int err; + memset(&msg, 0, sizeof(msg)); + for (i = 0; i < num; i++) { + msg.address = msgs[i].addr; + msg.request = (msgs[i].flags & I2C_M_RD) ? + DP_AUX_I2C_READ : + DP_AUX_I2C_WRITE; + msg.request |= DP_AUX_I2C_MOT; + /* Send a bare address packet to start the transaction. + * Zero sized messages specify an address only (bare + * address) transaction. + */ + msg.buffer = NULL; + msg.size = 0; + err = drm_dp_i2c_do_msg(aux, &msg); + if (err < 0) + break; /* * Many hardware implementations support FIFOs larger than a * single byte, but it has been empirically determined that @@ -678,30 +704,28 @@ static int drm_dp_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, * transferred byte-by-byte. */ for (j = 0; j < msgs[i].len; j++) { - memset(&msg, 0, sizeof(msg)); - msg.address = msgs[i].addr; - - msg.request = (msgs[i].flags & I2C_M_RD) ? - DP_AUX_I2C_READ : - DP_AUX_I2C_WRITE; - - /* - * All messages except the last one are middle-of- - * transfer messages. - */ - if ((i < num - 1) || (j < msgs[i].len - 1)) - msg.request |= DP_AUX_I2C_MOT; - msg.buffer = msgs[i].buf + j; msg.size = 1; err = drm_dp_i2c_do_msg(aux, &msg); if (err < 0) - return err; + break; } + if (err < 0) + break; } + if (err >= 0) + err = num; + /* Send a bare address packet to close out the transaction. + * Zero sized messages specify an address only (bare + * address) transaction. + */ + msg.request &= ~DP_AUX_I2C_MOT; + msg.buffer = NULL; + msg.size = 0; + (void)drm_dp_i2c_do_msg(aux, &msg); - return num; + return err; } static const struct i2c_algorithm drm_dp_i2c_algo = { @@ -710,13 +734,15 @@ static const struct i2c_algorithm drm_dp_i2c_algo = { }; /** - * drm_dp_aux_register_i2c_bus() - register an I2C adapter for I2C-over-AUX + * drm_dp_aux_register() - initialise and register aux channel * @aux: DisplayPort AUX channel * * Returns 0 on success or a negative error code on failure. */ -int drm_dp_aux_register_i2c_bus(struct drm_dp_aux *aux) +int drm_dp_aux_register(struct drm_dp_aux *aux) { + mutex_init(&aux->hw_mutex); + aux->ddc.algo = &drm_dp_i2c_algo; aux->ddc.algo_data = aux; aux->ddc.retries = 3; @@ -731,14 +757,14 @@ int drm_dp_aux_register_i2c_bus(struct drm_dp_aux *aux) return i2c_add_adapter(&aux->ddc); } -EXPORT_SYMBOL(drm_dp_aux_register_i2c_bus); +EXPORT_SYMBOL(drm_dp_aux_register); /** - * drm_dp_aux_unregister_i2c_bus() - unregister an I2C-over-AUX adapter + * drm_dp_aux_unregister() - unregister an AUX adapter * @aux: DisplayPort AUX channel */ -void drm_dp_aux_unregister_i2c_bus(struct drm_dp_aux *aux) +void drm_dp_aux_unregister(struct drm_dp_aux *aux) { i2c_del_adapter(&aux->ddc); } -EXPORT_SYMBOL(drm_dp_aux_unregister_i2c_bus); +EXPORT_SYMBOL(drm_dp_aux_unregister); |
