[PATCH V3 1/2] soc: qcom: aoss: Expose send for generic usecase

Deepak Kumar Singh
2021-05-06T17:08:30Z

Not all upcoming usecases will have an interface to allow the aoss
driver to hook onto. Expose the send api and create a get function to
enable drivers to send their own messages to aoss.

Signed-off-by: Chris Lew <clew@codeaurora.org>
Signed-off-by: Deepak Kumar Singh <deesin@codeaurora.org>
---
drivers/soc/qcom/qcom_aoss.c | 70 ++++++++++++++++++++++++++++++++++++--
include/linux/soc/qcom/qcom_aoss.h | 33 ++++++++++++++++++
2 files changed, 101 insertions(+), 2 deletions(-)
create mode 100644 include/linux/soc/qcom/qcom_aoss.h

diff --git a/drivers/soc/qcom/qcom_aoss.c b/drivers/soc/qcom/qcom_aoss.c
index 53acb94..cd75d4d 100644
--- a/drivers/soc/qcom/qcom_aoss.c
+++ b/drivers/soc/qcom/qcom_aoss.c
@@ -8,10 +8,12 @@
#include <linux/io.h>
#include <linux/mailbox_client.h>
#include <linux/module.h>
+#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/pm_domain.h>
#include <linux/thermal.h>
#include <linux/slab.h>
+#include <linux/soc/qcom/qcom_aoss.h>

#define QMP_DESC_MAGIC 0x0
#define QMP_DESC_VERSION 0x4
@@ -61,6 +63,7 @@ struct qmp_cooling_device {
* @mbox_chan: mailbox channel used to ring the doorbell on transmit
* @offset: offset within @msgram where messages should be written
* @size: maximum size of the messages to be transmitted
+ * @orphan: tarcks whether qmp handle is valid
* @event: wait_queue for synchronization with the IRQ
* @tx_lock: provides synchronization between multiple callers of qmp_send()
* @qdss_clk: QDSS clock hw struct
@@ -76,6 +79,8 @@ struct qmp {

size_t offset;
size_t size;
+ atomic_t orphan;
+ struct kref refcount;

wait_queue_head_t event;

@@ -223,11 +228,17 @@ static bool qmp_message_empty(struct qmp *qmp)
*
* Return: 0 on success, negative errno on failure
*/
-static int qmp_send(struct qmp *qmp, const void *data, size_t len)
+int qmp_send(struct qmp *qmp, const void *data, size_t len)
{
long time_left;
int ret;

+ if (WARN_ON(IS_ERR_OR_NULL(qmp) || !data))
+ return -EINVAL;
+
+ if (atomic_read(&qmp->orphan))
+ return -EINVAL;
+
if (WARN_ON(len + sizeof(u32) > qmp->size))
return -EINVAL;

@@ -261,6 +272,7 @@ static int qmp_send(struct qmp *qmp, const void *data, size_t len)

return ret;
}
+EXPORT_SYMBOL(qmp_send);

static int qmp_qdss_clk_prepare(struct clk_hw *hw)
{
@@ -515,6 +527,54 @@ static void qmp_cooling_devices_remove(struct qmp *qmp)
thermal_cooling_device_unregister(qmp->cooling_devs[i].cdev);
}

+/**
+ * qmp_get() - get a qmp handle from a device
+ * @dev: client device pointer
+ *
+ * Return: handle to qmp device on success, ERR_PTR() on failure
+ */
+struct qmp *qmp_get(struct device *dev)
+{
+ struct platform_device *pdev;
+ struct device_node *np;
+ struct qmp *qmp;
+
+ if (!dev || !dev->of_node)
+ return ERR_PTR(-EINVAL);
+
+ np = of_parse_phandle(dev->of_node, "qcom,qmp", 0);
+ if (!np)
+ return ERR_PTR(-ENODEV);
+
+ pdev = of_find_device_by_node(np);
+ of_node_put(np);
+ if (!pdev)
+ return ERR_PTR(-EINVAL);
+
+ qmp = platform_get_drvdata(pdev);
+ platform_device_put(pdev);
+
+ if (qmp)
+ kref_get(&qmp->refcount);
+
+ return qmp ? qmp : ERR_PTR(-EPROBE_DEFER);
+}
+EXPORT_SYMBOL(qmp_get);
+
+static void qmp_handle_release(struct kref *ref)
+{
+ struct qmp *qmp = container_of(ref, struct qmp, refcount);
+
+ kfree(qmp);
+}
+
+void qmp_put(struct qmp *qmp)
+{
+ if (!IS_ERR_OR_NULL(qmp))
+ kref_put(&qmp->refcount, qmp_handle_release);
+}
+EXPORT_SYMBOL(qmp_put);
+
static int qmp_probe(struct platform_device *pdev)
{
struct resource *res;
@@ -522,13 +582,14 @@ static int qmp_probe(struct platform_device *pdev)
int irq;
int ret;

- qmp = devm_kzalloc(&pdev->dev, sizeof(*qmp), GFP_KERNEL);
+ qmp = kzalloc(sizeof(*qmp), GFP_KERNEL);
if (!qmp)
return -ENOMEM;

qmp->dev = &pdev->dev;
init_waitqueue_head(&qmp->event);
mutex_init(&qmp->tx_lock);
+ kref_init(&qmp->refcount);

res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
qmp->msgram = devm_ioremap_resource(&pdev->dev, res);
@@ -569,6 +630,8 @@ static int qmp_probe(struct platform_device *pdev)

platform_set_drvdata(pdev, qmp);

+ atomic_set(&qmp->orphan, 0);
+
return 0;

err_remove_qdss_clk:
@@ -577,6 +640,7 @@ static int qmp_probe(struct platform_device *pdev)
qmp_close(qmp);
err_free_mbox:
mbox_free_channel(qmp->mbox_chan);
+ kfree(qmp);

return ret;
}
@@ -590,7 +654,9 @@ static int qmp_remove(struct platform_device *pdev)
qmp_cooling_devices_remove(qmp);

qmp_close(qmp);
+ atomic_set(&qmp->orphan, 1);
mbox_free_channel(qmp->mbox_chan);
+ kref_put(&qmp->refcount, qmp_handle_release);

return 0;
}
diff --git a/include/linux/soc/qcom/qcom_aoss.h b/include/linux/soc/qcom/qcom_aoss.h
new file mode 100644
index 0000000..27d00f7
--- /dev/null
+++ b/include/linux/soc/qcom/qcom_aoss.h
@@ -0,0 +1,33 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2020, The Linux Foundation. All rights reserved.
+ */
+
+#ifndef __QCOM_AOSS_H__
+#define __QCOM_AOSS_H__
+
+#include <linux/err.h>
+#include <linux/device.h>
+
+struct qmp;
+
+#if IS_ENABLED(CONFIG_QCOM_AOSS_QMP)
+
+int qmp_send(struct qmp *qmp, const void *data, size_t len);
+struct qmp *qmp_get(struct device *dev);
+
+#else
+
+static inline int qmp_send(struct qmp *qmp, const void *data, size_t len)
+{
+ return -ENODEV;
+}
+
+static inline struct qmp *qmp_get(struct device *dev)
+{
+ return ERR_PTR(-ENODEV);
+}
+
+#endif
+
+#endif