diff mbox series

[V2,1/2] soc: qcom: aoss: Expose send for generic usecase

Message ID 1617943188-23278-2-git-send-email-deesin@qti.qualcomm.com (mailing list archive)
State New
Headers show
Series soc: qcom: aoss: Expose send for generic usecase | expand

Commit Message

Deepak Kumar Singh April 9, 2021, 4:39 a.m. UTC
From: Deepak Kumar Singh <deesin@codeaurora.org>

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       | 50 +++++++++++++++++++++++++++++++++++++-
 include/linux/soc/qcom/qcom_aoss.h | 33 +++++++++++++++++++++++++
 2 files changed, 82 insertions(+), 1 deletion(-)
 create mode 100644 include/linux/soc/qcom/qcom_aoss.h

Comments

Bjorn Andersson April 13, 2021, 9:12 p.m. UTC | #1
On Thu 08 Apr 23:39 CDT 2021, Deepak Kumar Singh wrote:
[..]
> +/**
> + * 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);
> +	if (!pdev)
> +		return ERR_PTR(-EINVAL);
> +
> +	qmp = platform_get_drvdata(pdev);
> +	return qmp ? qmp : ERR_PTR(-EPROBE_DEFER);
> +}
> +EXPORT_SYMBOL(qmp_get);
> +
> +void qmp_put(struct platform_device *pdev)
> +{
> +	platform_device_put(pdev);

I was expecting that the devres allocated struct qmp would stick around
until the struct device's release callback came. As described in my
answer to Mani yesterday I was wrong.

As such you need to make sure that struct qmp stays around until
qmp_remove() and all qmp_put() calls has been made.

I presume a reasonable way to achieve this is to not use devm to
allocate our struct qmp, add a kref to the object. So this would have to
be a kref_put() on that instead of the platform_device_put() I asked you
to implement here.

Sorry about that.


The rest of the patch looks good.

Regards,
Bjorn
Deepak Kumar Singh May 5, 2021, 7:44 a.m. UTC | #2
On 4/14/2021 2:42 AM, Bjorn Andersson wrote:
> On Thu 08 Apr 23:39 CDT 2021, Deepak Kumar Singh wrote:
> [..]
>> +/**
>> + * 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);
>> +	if (!pdev)
>> +		return ERR_PTR(-EINVAL);
>> +
>> +	qmp = platform_get_drvdata(pdev);
>> +	return qmp ? qmp : ERR_PTR(-EPROBE_DEFER);
>> +}
>> +EXPORT_SYMBOL(qmp_get);
>> +
>> +void qmp_put(struct platform_device *pdev)
>> +{
>> +	platform_device_put(pdev);
> I was expecting that the devres allocated struct qmp would stick around
> until the struct device's release callback came. As described in my
> answer to Mani yesterday I was wrong.
>
> As such you need to make sure that struct qmp stays around until
> qmp_remove() and all qmp_put() calls has been made.
>
> I presume a reasonable way to achieve this is to not use devm to
> allocate our struct qmp, add a kref to the object. So this would have to
> be a kref_put() on that instead of the platform_device_put() I asked you
> to implement here.
>
> Sorry about that.
>
>
> The rest of the patch looks good.
>
> Regards,
> Bjorn

Hi Bjorn,

Even if we use kref_put(), would it not require platform_device_put()? 
As per my understanding of_find_device_by_node(np) will increment 
node/pdev kobj refcount which both needs to be decremented.
diff mbox series

Patch

diff --git a/drivers/soc/qcom/qcom_aoss.c b/drivers/soc/qcom/qcom_aoss.c
index 53acb94..0e397a7 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 +79,7 @@  struct qmp {
 
 	size_t offset;
 	size_t size;
+	atomic_t  orphan;
 
 	wait_queue_head_t event;
 
@@ -223,11 +227,17 @@  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 +271,7 @@  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 +526,40 @@  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);
+	if (!pdev)
+		return ERR_PTR(-EINVAL);
+
+	qmp = platform_get_drvdata(pdev);
+	return qmp ? qmp : ERR_PTR(-EPROBE_DEFER);
+}
+EXPORT_SYMBOL(qmp_get);
+
+void qmp_put(struct platform_device *pdev)
+{
+	platform_device_put(pdev);
+}
+EXPORT_SYMBOL(qmp_put);
+
 static int qmp_probe(struct platform_device *pdev)
 {
 	struct resource *res;
@@ -569,6 +614,8 @@  static int qmp_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, qmp);
 
+	atomic_set(&qmp->orphan, 0);
+
 	return 0;
 
 err_remove_qdss_clk:
@@ -590,6 +637,7 @@  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);
 
 	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