[PATCH v1 5/5] i2c: i2c-qcom-geni: Add Block event interrupt support

Jyothi Kumar Seerapu quic_jseerapu at quicinc.com
Mon Oct 28 06:04:07 UTC 2024



On 10/16/2024 8:36 PM, Andi Shyti wrote:
> Hi Jyothi,
> 
> ...
> 
>> @@ -523,26 +576,49 @@ static int geni_i2c_gpi(struct geni_i2c_dev *gi2c, struct i2c_msg *msg,
>>   	enum dma_transfer_direction dma_dirn;
>>   	struct dma_async_tx_descriptor *desc;
>>   	int ret;
>> +	struct gpi_multi_xfer *gi2c_gpi_xfer;
>> +	dma_cookie_t cookie;
>>   
>>   	peripheral = config->peripheral_config;
>> -
>> -	dma_buf = i2c_get_dma_safe_msg_buf(msg, 1);
>> -	if (!dma_buf)
>> +	gi2c_gpi_xfer = &peripheral->multi_xfer;
>> +	gi2c_gpi_xfer->msg_idx_cnt = cur_msg_idx;
>> +	dma_buf = gi2c_gpi_xfer->dma_buf[gi2c_gpi_xfer->buf_idx];
>> +	addr = gi2c_gpi_xfer->dma_addr[gi2c_gpi_xfer->buf_idx];
>> +
>> +	dma_buf = i2c_get_dma_safe_msg_buf(&msgs[gi2c_gpi_xfer->msg_idx_cnt], 1);
>> +	if (!dma_buf) {
>> +		gi2c->err = -ENOMEM;
>>   		return -ENOMEM;
>> +	}
>>   
>>   	if (op == I2C_WRITE)
>>   		map_dirn = DMA_TO_DEVICE;
>>   	else
>>   		map_dirn = DMA_FROM_DEVICE;
>>   
>> -	addr = dma_map_single(gi2c->se.dev->parent, dma_buf, msg->len, map_dirn);
>> +	addr = dma_map_single(gi2c->se.dev->parent,
>> +			      dma_buf, msgs[gi2c_gpi_xfer->msg_idx_cnt].len,
> 
> You could save msgs[gi2c_gpi_xfer->msg_idx_cnt] in a separate
> variable to avoid this extra indexing.
> 
Thanks Andi, moved gi2c_gpi_xfer->msg_idx_cnt to separate local variable.
>> +			      map_dirn);
>>   	if (dma_mapping_error(gi2c->se.dev->parent, addr)) {
>> -		i2c_put_dma_safe_msg_buf(dma_buf, msg, false);
>> +		i2c_put_dma_safe_msg_buf(dma_buf, &msgs[gi2c_gpi_xfer->msg_idx_cnt],
>> +					 false);
>> +		gi2c->err = -ENOMEM;
>>   		return -ENOMEM;
>>   	}
>>   
>> +	if (gi2c->is_tx_multi_xfer) {
>> +		if (((gi2c_gpi_xfer->msg_idx_cnt + 1) % NUM_MSGS_PER_IRQ))
>> +			peripheral->flags |= QCOM_GPI_BLOCK_EVENT_IRQ;
>> +		else
>> +			peripheral->flags &= ~QCOM_GPI_BLOCK_EVENT_IRQ;
>> +
>> +		/* BEI bit to be cleared for last TRE */
>> +		if (gi2c_gpi_xfer->msg_idx_cnt == gi2c->num_msgs - 1)
>> +			peripheral->flags &= ~QCOM_GPI_BLOCK_EVENT_IRQ;
>> +	}
>> +
>>   	/* set the length as message for rx txn */
>> -	peripheral->rx_len = msg->len;
>> +	peripheral->rx_len = msgs[gi2c_gpi_xfer->msg_idx_cnt].len;
>>   	peripheral->op = op;
>>   
>>   	ret = dmaengine_slave_config(dma_chan, config);
>> @@ -560,25 +636,56 @@ static int geni_i2c_gpi(struct geni_i2c_dev *gi2c, struct i2c_msg *msg,
>>   	else
>>   		dma_dirn = DMA_DEV_TO_MEM;
>>   
>> -	desc = dmaengine_prep_slave_single(dma_chan, addr, msg->len, dma_dirn, flags);
>> +	desc = dmaengine_prep_slave_single(dma_chan, addr,
>> +					   msgs[gi2c_gpi_xfer->msg_idx_cnt].len,
>> +					   dma_dirn, flags);
>>   	if (!desc) {
>>   		dev_err(gi2c->se.dev, "prep_slave_sg failed\n");
>> -		ret = -EIO;
>> +		gi2c->err = -EIO;
>>   		goto err_config;
>>   	}
>>   
>>   	desc->callback_result = i2c_gpi_cb_result;
>>   	desc->callback_param = gi2c;
>>   
>> -	dmaengine_submit(desc);
>> -	*buf = dma_buf;
>> -	*dma_addr_p = addr;
>> +	if (!((msgs[cur_msg_idx].flags & I2C_M_RD) && op == I2C_WRITE)) {
>> +		gi2c_gpi_xfer->msg_idx_cnt++;
>> +		gi2c_gpi_xfer->buf_idx = (cur_msg_idx + 1) % QCOM_GPI_MAX_NUM_MSGS;
>> +	}
>> +	cookie = dmaengine_submit(desc);
>> +	if (dma_submit_error(cookie)) {
>> +		dev_err(gi2c->se.dev,
>> +			"%s: dmaengine_submit failed (%d)\n", __func__, cookie);
>> +		return -EINVAL;
> 
> goto err_config?
yes, updated it.
> 
>> +	}
>>   
>> +	if (gi2c->is_tx_multi_xfer) {
>> +		dma_async_issue_pending(gi2c->tx_c);
>> +		if ((cur_msg_idx == (gi2c->num_msgs - 1)) ||
>> +		    (gi2c_gpi_xfer->msg_idx_cnt >=
>> +		     QCOM_GPI_MAX_NUM_MSGS + gi2c_gpi_xfer->freed_msg_cnt)) {
>> +			ret = gpi_multi_desc_process(gi2c->se.dev, gi2c_gpi_xfer,
>> +						     gi2c->num_msgs, XFER_TIMEOUT,
>> +						     &gi2c->done);
>> +			if (ret) {
>> +				dev_dbg(gi2c->se.dev,
>> +					"I2C multi write msg transfer timeout: %d\n",
>> +					ret);
> 
> if you are returning an error, then print an error.
sure, updated it to error in V2 patch.
> 
>> +				gi2c->err = -ETIMEDOUT;
> 
> gi2c->err = ret?
Yes in this case, ret is -ETIMEDOUT, so updated in V2 patch as 
gi2c->err= ret.
> 
>> +				goto err_config;
>> +			}
>> +		}
>> +	} else {
>> +		/* Non multi descriptor message transfer */
>> +		*buf = dma_buf;
>> +		*dma_addr_p = addr;
>> +	}
>>   	return 0;
>>   
>>   err_config:
>> -	dma_unmap_single(gi2c->se.dev->parent, addr, msg->len, map_dirn);
>> -	i2c_put_dma_safe_msg_buf(dma_buf, msg, false);
>> +	dma_unmap_single(gi2c->se.dev->parent, addr,
>> +			 msgs[cur_msg_idx].len, map_dirn);
>> +	i2c_put_dma_safe_msg_buf(dma_buf, &msgs[cur_msg_idx], false);
>>   	return ret;
> 
> I would have one more label here:
> 
>     out:
> 	gi2c->err = ret;
> 
> 	return ret;
> 
> in order to avoid always assigning twice
Thanks, added new label as out and handled it.
> 
>>   }
>>   
>> @@ -590,6 +697,7 @@ static int geni_i2c_gpi_xfer(struct geni_i2c_dev *gi2c, struct i2c_msg msgs[], i
>>   	unsigned long time_left;
>>   	dma_addr_t tx_addr, rx_addr;
>>   	void *tx_buf = NULL, *rx_buf = NULL;
>> +	struct gpi_multi_xfer *tx_multi_xfer;
>>   	const struct geni_i2c_clk_fld *itr = gi2c->clk_fld;
>>   
>>   	config.peripheral_config = &peripheral;
>> @@ -603,6 +711,39 @@ static int geni_i2c_gpi_xfer(struct geni_i2c_dev *gi2c, struct i2c_msg msgs[], i
>>   	peripheral.set_config = 1;
>>   	peripheral.multi_msg = false;
>>   
>> +	gi2c->gpi_config = &peripheral;
>> +	gi2c->num_msgs = num;
>> +	gi2c->is_tx_multi_xfer = false;
>> +	gi2c->tx_irq_cnt = 0;
>> +
>> +	tx_multi_xfer = &peripheral.multi_xfer;
>> +	tx_multi_xfer->msg_idx_cnt = 0;
>> +	tx_multi_xfer->buf_idx = 0;
>> +	tx_multi_xfer->unmap_msg_cnt = 0;
>> +	tx_multi_xfer->freed_msg_cnt = 0;
>> +	tx_multi_xfer->irq_msg_cnt = 0;
>> +	tx_multi_xfer->irq_cnt = 0;
> 
> you can initialize tx_multi_xfer to "{ };" to avoid all these
> " = 0"
Sure, done memset tx_multi_xfer to 0 in V2 patch.
> 
>> +
>> +	/*
>> +	 * If number of write messages are four and higher then
>> +	 * configure hardware for multi descriptor transfers with BEI.
>> +	 */
>> +	if (num >= MIN_NUM_OF_MSGS_MULTI_DESC) {
>> +		gi2c->is_tx_multi_xfer = true;
>> +		for (i = 0; i < num; i++) {
>> +			if (msgs[i].flags & I2C_M_RD) {
>> +				/*
>> +				 * Multi descriptor transfer with BEI
>> +				 * support is enabled for write transfers.
>> +				 * Add BEI optimization support for read
>> +				 * transfers later.
>> +				 */
>> +				gi2c->is_tx_multi_xfer = false;
>> +				break;
>> +			}
>> +		}
>> +	}
>> +
>>   	for (i = 0; i < num; i++) {
>>   		gi2c->cur = &msgs[i];
>>   		gi2c->err = 0;
>> @@ -613,14 +754,16 @@ static int geni_i2c_gpi_xfer(struct geni_i2c_dev *gi2c, struct i2c_msg msgs[], i
>>   			peripheral.stretch = 1;
>>   
>>   		peripheral.addr = msgs[i].addr;
>> +		if (i > 0 && (!(msgs[i].flags & I2C_M_RD)))
>> +			peripheral.multi_msg = false;
>>   
>> -		ret =  geni_i2c_gpi(gi2c, &msgs[i], &config,
>> +		ret =  geni_i2c_gpi(gi2c, msgs, i, &config,
> 
> what is the point of passing 'i' if you always refer to msgs[i]
> in geni_i2c_gpi()?
Handled with new variable in "geni_i2c_gpi "and so no need to pass 
current i2c msg index, removed it in V2 patch.
> 
>>   				    &tx_addr, &tx_buf, I2C_WRITE, gi2c->tx_c);
>>   		if (ret)
>>   			goto err;
>>   
>>   		if (msgs[i].flags & I2C_M_RD) {
>> -			ret =  geni_i2c_gpi(gi2c, &msgs[i], &config,
>> +			ret =  geni_i2c_gpi(gi2c, msgs, i, &config,
>>   					    &rx_addr, &rx_buf, I2C_READ, gi2c->rx_c);
>>   			if (ret)
>>   				goto err;
>> @@ -628,18 +771,28 @@ static int geni_i2c_gpi_xfer(struct geni_i2c_dev *gi2c, struct i2c_msg msgs[], i
>>   			dma_async_issue_pending(gi2c->rx_c);
>>   		}
>>   
>> -		dma_async_issue_pending(gi2c->tx_c);
>> -
>> -		time_left = wait_for_completion_timeout(&gi2c->done, XFER_TIMEOUT);
>> -		if (!time_left)
>> -			gi2c->err = -ETIMEDOUT;
>> +		if (!gi2c->is_tx_multi_xfer) {
>> +			dma_async_issue_pending(gi2c->tx_c);
>> +			time_left = wait_for_completion_timeout(&gi2c->done, XFER_TIMEOUT);
>> +			if (!time_left) {
>> +				dev_err(gi2c->se.dev, "%s:I2C timeout\n", __func__);
>> +				gi2c->err = -ETIMEDOUT;
>> +			}
>> +		}
>>   
>>   		if (gi2c->err) {
>>   			ret = gi2c->err;
>>   			goto err;
>>   		}
>>   
>> -		geni_i2c_gpi_unmap(gi2c, &msgs[i], tx_buf, tx_addr, rx_buf, rx_addr);
>> +		if (!gi2c->is_tx_multi_xfer) {
>> +			geni_i2c_gpi_unmap(gi2c, &msgs[i], tx_buf, tx_addr, rx_buf, rx_addr);
>> +		} else {
>> +			if (gi2c->tx_irq_cnt != tx_multi_xfer->irq_cnt) {
> 
>     else if (...) {
>     	...
>     }
Sure, else if used here in V2 patch.
> 
> Andi

Regards,
JyothiKumar


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