/*
 * Copyright (c) 2015, Sony Mobile Communications Inc.
 * Copyright (c) 2013, The Linux Foundation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 and
 * only version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/soc/qcom/smd.h>

#include "qrtr.h"

struct qrtr_smd_dev {
	struct qrtr_endpoint ep;
	struct qcom_smd_channel *channel;
	struct device *dev;
};

/* from smd to qrtr */
static int qcom_smd_qrtr_callback(struct qcom_smd_channel *channel,
				  const void *data, size_t len)
{
	struct qrtr_smd_dev *qdev = qcom_smd_get_drvdata(channel);
	int rc;

	if (!qdev)
		return -EAGAIN;

	rc = qrtr_endpoint_post(&qdev->ep, data, len);
	if (rc == -EINVAL) {
		dev_err(qdev->dev, "invalid ipcrouter packet\n");
		/* return 0 to let smd drop the packet */
		rc = 0;
	}

	return rc;
}

/* from qrtr to smd */
static int qcom_smd_qrtr_send(struct qrtr_endpoint *ep, struct sk_buff *skb)
{
	struct qrtr_smd_dev *qdev = container_of(ep, struct qrtr_smd_dev, ep);
	int rc;

	rc = skb_linearize(skb);
	if (rc)
		goto out;

	rc = qcom_smd_send(qdev->channel, skb->data, skb->len);

out:
	if (rc)
		kfree_skb(skb);
	else
		consume_skb(skb);
	return rc;
}

static int qcom_smd_qrtr_probe(struct qcom_smd_device *sdev)
{
	struct qrtr_smd_dev *qdev;
	int rc;

	qdev = devm_kzalloc(&sdev->dev, sizeof(*qdev), GFP_KERNEL);
	if (!qdev)
		return -ENOMEM;

	qdev->channel = sdev->channel;
	qdev->dev = &sdev->dev;
	qdev->ep.xmit = qcom_smd_qrtr_send;

	rc = qrtr_endpoint_register(&qdev->ep, QRTR_EP_NID_AUTO);
	if (rc)
		return rc;

	qcom_smd_set_drvdata(sdev->channel, qdev);
	dev_set_drvdata(&sdev->dev, qdev);

	dev_dbg(&sdev->dev, "Qualcomm SMD QRTR driver probed\n");

	return 0;
}

static void qcom_smd_qrtr_remove(struct qcom_smd_device *sdev)
{
	struct qrtr_smd_dev *qdev = dev_get_drvdata(&sdev->dev);

	qrtr_endpoint_unregister(&qdev->ep);

	dev_set_drvdata(&sdev->dev, NULL);
}

static const struct qcom_smd_id qcom_smd_qrtr_smd_match[] = {
	{ "IPCRTR" },
	{}
};

static struct qcom_smd_driver qcom_smd_qrtr_driver = {
	.probe = qcom_smd_qrtr_probe,
	.remove = qcom_smd_qrtr_remove,
	.callback = qcom_smd_qrtr_callback,
	.smd_match_table = qcom_smd_qrtr_smd_match,
	.driver = {
		.name = "qcom_smd_qrtr",
		.owner = THIS_MODULE,
	},
};

module_qcom_smd_driver(qcom_smd_qrtr_driver);

MODULE_DESCRIPTION("Qualcomm IPC-Router SMD interface driver");
MODULE_LICENSE("GPL v2");
t type='submit' value='search'/>
</form>
</td></tr></table>
<div class='path'>path: <a href='/cgit.cgi/linux/net-next.git/commit/?id=ae4a3e028bb8b59e7cfeb0cc9ef03d885182ce8b'>root</a>/<a href='/cgit.cgi/linux/net-next.git/commit/include?id=ae4a3e028bb8b59e7cfeb0cc9ef03d885182ce8b'>include</a>/<a href='/cgit.cgi/linux/net-next.git/commit/include/dt-bindings?id=ae4a3e028bb8b59e7cfeb0cc9ef03d885182ce8b'>dt-bindings</a>/<a href='/cgit.cgi/linux/net-next.git/commit/include/dt-bindings/interrupt-controller?id=ae4a3e028bb8b59e7cfeb0cc9ef03d885182ce8b'>interrupt-controller</a>/<a href='/cgit.cgi/linux/net-next.git/commit/include/dt-bindings/interrupt-controller/mips-gic.h?id=ae4a3e028bb8b59e7cfeb0cc9ef03d885182ce8b'>mips-gic.h</a></div><div class='content'><div class='cgit-panel'><b>diff options</b><form method='get'><input type='hidden' name='id' value='ae4a3e028bb8b59e7cfeb0cc9ef03d885182ce8b'/><table><tr><td colspan='2'/></tr><tr><td class='label'>context:</td><td class='ctrl'><select name='context' onchange='this.form.submit();'><option value='1'>1</option><option value='2'>2</option><option value='3' selected='selected'>3</option><option value='4'>4</option><option value='5'>5</option><option value='6'>6</option><option value='7'>7</option><option value='8'>8</option><option value='9'>9</option><option value='10'>10</option><option value='15'>15</option><option value='20'>20</option><option value='25'>25</option><option value='30'>30</option><option value='35'>35</option><option value='40'>40</option></select></td></tr><tr><td class='label'>space:</td><td class='ctrl'><select name='ignorews' onchange='this.form.submit();'><option value='0' selected='selected'>include</option><option value='1'>ignore</option></select></td></tr><tr><td class='label'>mode:</td><td class='ctrl'><select name='dt' onchange='this.form.submit();'><option value='0' selected='selected'>unified</option><option value='1'>ssdiff</option><option value='2'>stat only</option></select></td></tr><tr><td/><td class='ctrl'><noscript><input type='submit' value='reload'/></noscript></td></tr></table></form></div><table summary='commit info' class='commit-info'>
<tr><th>author</th><td>Tony Lindgren &lt;tony@atomide.com&gt;</td><td class='right'>2017-01-19 08:49:07 -0800</td></tr>
<tr><th>committer</th><td>Vinod Koul &lt;vinod.koul@intel.com&gt;</td><td class='right'>2017-01-25 11:29:11 +0530</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/include/dt-bindings/interrupt-controller/mips-gic.h?id=ae4a3e028bb8b59e7cfeb0cc9ef03d885182ce8b'>ae4a3e028bb8b59e7cfeb0cc9ef03d885182ce8b</a> (<a href='/cgit.cgi/linux/net-next.git/patch/include/dt-bindings/interrupt-controller/mips-gic.h?id=ae4a3e028bb8b59e7cfeb0cc9ef03d885182ce8b'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=ae4a3e028bb8b59e7cfeb0cc9ef03d885182ce8b'>139fc7e29f97d6bb6c4dca2a97be2dc3f824bd51</a> /<a href='/cgit.cgi/linux/net-next.git/tree/include/dt-bindings/interrupt-controller/mips-gic.h?id=ae4a3e028bb8b59e7cfeb0cc9ef03d885182ce8b'>include/dt-bindings/interrupt-controller/mips-gic.h</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/include/dt-bindings/interrupt-controller/mips-gic.h?id=49def1853334396f948dcb4cedb9347abb318df5'>49def1853334396f948dcb4cedb9347abb318df5</a> (<a href='/cgit.cgi/linux/net-next.git/diff/include/dt-bindings/interrupt-controller/mips-gic.h?id=ae4a3e028bb8b59e7cfeb0cc9ef03d885182ce8b&amp;id2=49def1853334396f948dcb4cedb9347abb318df5'>diff</a>)</td></tr></table>
<div class='commit-subject'>dmaengine: cppi41: Fix runtime PM timeouts with USB mass storage</div><div class='commit-msg'>Commit fdea2d09b997 ("dmaengine: cppi41: Add basic PM runtime support")
added runtime PM support for cppi41, but had corner case issues. Some of
the issues were fixed with commit 098de42ad670 ("dmaengine: cppi41: Fix
unpaired pm runtime when only a USB hub is connected"). That fix however
caused a new regression where we can get error -115 messages with USB on
BeagleBone when connecting a USB mass storage device to a hub.

This is because when connecting a USB mass storage device to a hub, the
initial DMA transfers can take over 200ms to complete and cppi41
autosuspend delay times out.

To fix the issue, we want to implement refcounting for chan_busy array
that contains the active dma transfers. Increasing the autosuspend delay
won't help as that the delay could be potentially seconds, and it's best
to let the USB subsystem to deal with the timeouts on errors.

The earlier attempt for runtime PM was buggy as the pm_runtime_get/put()
calls could get unpaired easily as they did not follow the state of
the chan_busy array as described in commit 098de42ad670 ("dmaengine:
cppi41: Fix unpaired pm runtime when only a USB hub is connected".

Let's fix the issue by adding pm_runtime_get() to where a new transfer
is added to the chan_busy array, and calls to pm_runtime_put() where
chan_busy array entry is cleared. This prevents any autosuspend timeouts
from happening while dma transfers are active.

Fixes: 098de42ad670 ("dmaengine: cppi41: Fix unpaired pm runtime when
only a USB hub is connected")
Fixes: fdea2d09b997 ("dmaengine: cppi41: Add basic PM runtime support")
Cc: Andy Shevchenko &lt;andy.shevchenko@gmail.com&gt;
Cc: Bin Liu &lt;b-liu@ti.com&gt;
Cc: Grygorii Strashko &lt;grygorii.strashko@ti.com&gt;
Cc: Kevin Hilman &lt;khilman@baylibre.com&gt;
Cc: Patrick Titiano &lt;ptitiano@baylibre.com&gt;
Cc: Sergei Shtylyov &lt;sergei.shtylyov@cogentembedded.com&gt;
Signed-off-by: Tony Lindgren &lt;tony@atomide.com&gt;
Tested-by: Bin Liu &lt;b-liu@ti.com&gt;
Signed-off-by: Vinod Koul &lt;vinod.koul@intel.com&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=ae4a3e028bb8b59e7cfeb0cc9ef03d885182ce8b'>Diffstat</a> (limited to 'include/dt-bindings/interrupt-controller/mips-gic.h')</div><table summary='diffstat' class='diffstat'>