Re: [PATCH] rpmsg: qcom_smd: Access APCS through mailbox framework

From: Jitendra Sharma
Date: Wed Dec 06 2017 - 07:08:14 EST


Hi Bjorn,


On 11/16/2017 12:38 PM, Bjorn Andersson wrote:
Attempt to acquire the APCS IPC through the mailbox framework and fall
back to the old syscon based approach, to allow us to move away from
using the syscon.

Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
---
drivers/rpmsg/qcom_smd.c | 62 +++++++++++++++++++++++++++++++++---------------
1 file changed, 43 insertions(+), 19 deletions(-)

diff --git a/drivers/rpmsg/qcom_smd.c b/drivers/rpmsg/qcom_smd.c
index b01774e9fac0..ef2a526ebc8f 100644
--- a/drivers/rpmsg/qcom_smd.c
+++ b/drivers/rpmsg/qcom_smd.c
@@ -14,6 +14,7 @@
#include <linux/interrupt.h>
#include <linux/io.h>
+#include <linux/mailbox_client.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of_irq.h>
@@ -107,6 +108,8 @@ static const struct {
* @ipc_regmap: regmap handle holding the outgoing ipc register
* @ipc_offset: offset within @ipc_regmap of the register for ipc
* @ipc_bit: bit in the register at @ipc_offset of @ipc_regmap
+ * @mbox_client: mailbox client handle
+ * @mbox_chan: apcs ipc mailbox channel handle
* @channels: list of all channels detected on this edge
* @channels_lock: guard for modifications of @channels
* @allocated: array of bitmaps representing already allocated channels
@@ -129,6 +132,9 @@ struct qcom_smd_edge {
int ipc_offset;
int ipc_bit;
+ struct mbox_client mbox_client;
+ struct mbox_chan *mbox_chan;
+
struct list_head channels;
spinlock_t channels_lock;
@@ -365,7 +371,12 @@ static void qcom_smd_signal_channel(struct qcom_smd_channel *channel)
{
struct qcom_smd_edge *edge = channel->edge;
- regmap_write(edge->ipc_regmap, edge->ipc_offset, BIT(edge->ipc_bit));
+ if (edge->mbox_chan) {
+ mbox_send_message(edge->mbox_chan, NULL);
mbox_send_message could fail. So return value should be checked
+ mbox_client_txdone(edge->mbox_chan, 0);
+ } else {
+ regmap_write(edge->ipc_regmap, edge->ipc_offset, BIT(edge->ipc_bit));
+ }
}
/*
@@ -1268,27 +1279,37 @@ static int qcom_smd_parse_edge(struct device *dev,
key = "qcom,remote-pid";
of_property_read_u32(node, key, &edge->remote_pid);
- syscon_np = of_parse_phandle(node, "qcom,ipc", 0);
- if (!syscon_np) {
- dev_err(dev, "no qcom,ipc node\n");
- return -ENODEV;
- }
+ edge->mbox_client.dev = dev;
+ edge->mbox_client.knows_txdone = true;
+ edge->mbox_chan = mbox_request_channel(&edge->mbox_client, 0);
+ if (IS_ERR(edge->mbox_chan)) {
+ if (PTR_ERR(edge->mbox_chan) != -ENODEV)
+ return PTR_ERR(edge->mbox_chan);
- edge->ipc_regmap = syscon_node_to_regmap(syscon_np);
- if (IS_ERR(edge->ipc_regmap))
- return PTR_ERR(edge->ipc_regmap);
+ edge->mbox_chan = NULL;
- key = "qcom,ipc";
- ret = of_property_read_u32_index(node, key, 1, &edge->ipc_offset);
- if (ret < 0) {
- dev_err(dev, "no offset in %s\n", key);
- return -EINVAL;
- }
+ syscon_np = of_parse_phandle(node, "qcom,ipc", 0);
+ if (!syscon_np) {
+ dev_err(dev, "no qcom,ipc node\n");
+ return -ENODEV;
+ }
- ret = of_property_read_u32_index(node, key, 2, &edge->ipc_bit);
- if (ret < 0) {
- dev_err(dev, "no bit in %s\n", key);
- return -EINVAL;
+ edge->ipc_regmap = syscon_node_to_regmap(syscon_np);
+ if (IS_ERR(edge->ipc_regmap))
+ return PTR_ERR(edge->ipc_regmap);
+
+ key = "qcom,ipc";
+ ret = of_property_read_u32_index(node, key, 1, &edge->ipc_offset);
+ if (ret < 0) {
+ dev_err(dev, "no offset in %s\n", key);
+ return -EINVAL;
+ }
+
+ ret = of_property_read_u32_index(node, key, 2, &edge->ipc_bit);
+ if (ret < 0) {
+ dev_err(dev, "no bit in %s\n", key);
+ return -EINVAL;
+ }
}
ret = of_property_read_string(node, "label", &edge->name);
@@ -1394,6 +1415,8 @@ struct qcom_smd_edge *qcom_smd_register_edge(struct device *parent,
return edge;
unregister_dev:
+ if (!IS_ERR_OR_NULL(edge->mbox_chan))
+ mbox_free_channel(edge->mbox_chan);
put_device(&edge->dev);
return ERR_PTR(ret);
}
@@ -1422,6 +1445,7 @@ int qcom_smd_unregister_edge(struct qcom_smd_edge *edge)
if (ret)
dev_warn(&edge->dev, "can't remove smd device: %d\n", ret);
+ mbox_free_channel(edge->mbox_chan);
device_unregister(&edge->dev);
return 0;