* 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)
* 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;
/*
* 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)
{
* 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;
{
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
* 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 = {
};
/**
- * 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;
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);