lkml.org 
[lkml]   [2015]   [Jul]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v5 2/8] firmware: add support for ARM System Control and Power Interface(SCPI) protocol


On 29/07/15 09:05, Jassi Brar wrote:
> On Thu, Jul 23, 2015 at 4:40 PM, Sudeep Holla <sudeep.holla@arm.com> wrote:
>
> ...
>
>> +static int scpi_probe(struct platform_device *pdev)
>> +{
>> + int count, idx, ret;
>> + struct resource res;
>> + struct scpi_chan *scpi_chan;
>> + struct device *dev = &pdev->dev;
>> + struct device_node *np = dev->of_node;
>> +
>> + scpi_info = devm_kzalloc(dev, sizeof(*scpi_info), GFP_KERNEL);
>> + if (!scpi_info)
>> + return -ENOMEM;
>> +
>> + count = of_count_phandle_with_args(np, "mboxes", "#mbox-cells");
>> + if (count < 0) {
>> + dev_err(dev, "no mboxes property in '%s'\n", np->full_name);
>> + return -ENODEV;
>> + }
>> +
>> + scpi_chan = devm_kcalloc(dev, count, sizeof(*scpi_chan), GFP_KERNEL);
>> + if (!scpi_chan)
>> + return -ENOMEM;
>> +
>> + for (idx = 0; idx < count; idx++) {
>> + resource_size_t size;
>> + struct scpi_chan *pchan = scpi_chan + idx;
>> + struct mbox_client *cl = &pchan->cl;
>> + struct device_node *shmem = of_parse_phandle(np, "shmem", idx);
>> +
>> + if (of_address_to_resource(shmem, 0, &res)) {
>> + dev_err(dev, "failed to get SCPI payload mem resource\n");
>> + ret = -EINVAL;
>> + goto err;
>> + }
>> +
>> + size = resource_size(&res);
>> + pchan->rx_payload = devm_ioremap(dev, res.start, size);
>> + if (!pchan->rx_payload) {
>> + dev_err(dev, "failed to ioremap SCPI payload\n");
>> + ret = -EADDRNOTAVAIL;
>> + goto err;
>> + }
>> + pchan->tx_payload = pchan->rx_payload + (size >> 1);
>> +
>> + cl->dev = dev;
>> + cl->rx_callback = scpi_handle_remote_msg;
>> + cl->tx_prepare = scpi_tx_prepare;
>> + cl->tx_block = true;
>> + cl->tx_tout = 50;
>> + cl->knows_txdone = false; /* controller can ack */
>>
> This is the cause of your problems that you think should be solved by
> using hrtimer.
>

Ah sorry, it's stupid mistake on my part while writing the comment. It
should have been controller can't ack, fixed locally now thanks for
pointing it out.

> Controller may or may not (like MHU) set txdone_irq. However every
> scpi command (struct scpi_ops members) is replied to as a response
> packet reporting success or failure.

No that's not true, I have already mentioned that couple of times in the
other thread. It's just wrong comment here which went unnoticed from
day#1, sorry for that.

> So the client should set 'knows_txdone' to be true unless it is told
> the controller on that platform supports txdone_irq (what you call
> 'ack').
>

I got the concept but SCP can't ack via protocol, protocol has no such
provision and it sets flags in MHU status register.

Regards,
Sudeep


\
 
 \ /
  Last update: 2015-07-29 21:10    [W:0.093 / U:0.228 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site