Re: [PATCH 3/3] soc: qcom: Add AOSS QMP genpd provider

From: Sai Prakash Ranjan
Date: Mon Nov 26 2018 - 22:31:49 EST

Hi Bjorn,

On 11/12/2018 1:35 PM, Bjorn Andersson wrote:
The AOSS QMP genpd provider implements control over power-related
resources related to low-power state associated with the remoteprocs in
the system as well as control over a set of clocks related to debug
hardware in the SoC.

Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
drivers/soc/qcom/Kconfig | 8 ++
drivers/soc/qcom/Makefile | 1 +
drivers/soc/qcom/aoss-qmp-pd.c | 135 +++++++++++++++++++++++++++++++++
3 files changed, 144 insertions(+)
create mode 100644 drivers/soc/qcom/aoss-qmp-pd.c

diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig
index ba08fc00d7f5..e1eda3d59748 100644
--- a/drivers/soc/qcom/Kconfig
+++ b/drivers/soc/qcom/Kconfig
@@ -10,6 +10,14 @@ config QCOM_AOSS_QMP
micro-controller in the AOSS, using QMP, to control certain resource
that are not exposed through RPMh.
+ tristate "Qualcomm AOSS Messaging Power Domain driver"
+ depends on QCOM_AOSS_QMP
+ help
+ This driver provides the means of controlling the AOSSs handling of
+ low-power state for resources related to the remoteproc subsystems as
+ well as controlling the debug clocks.
bool "Qualcomm Command DB"
diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile
index d0d7fdc94d9a..ebfa414a5b77 100644
--- a/drivers/soc/qcom/Makefile
+++ b/drivers/soc/qcom/Makefile
@@ -1,6 +1,7 @@
# SPDX-License-Identifier: GPL-2.0
CFLAGS_rpmh-rsc.o := -I$(src)
obj-$(CONFIG_QCOM_AOSS_QMP) += aoss-qmp.o
+obj-$(CONFIG_QCOM_AOSS_QMP_PD) += aoss-qmp-pd.o
obj-$(CONFIG_QCOM_GENI_SE) += qcom-geni-se.o
obj-$(CONFIG_QCOM_COMMAND_DB) += cmd-db.o
obj-$(CONFIG_QCOM_GLINK_SSR) += glink_ssr.o
diff --git a/drivers/soc/qcom/aoss-qmp-pd.c b/drivers/soc/qcom/aoss-qmp-pd.c
new file mode 100644
index 000000000000..467d0db4abfa
--- /dev/null
+++ b/drivers/soc/qcom/aoss-qmp-pd.c
@@ -0,0 +1,135 @@
+// SPDX-License-Identifier: GPL-2.0
+ * Copyright (c) 2018, Linaro Ltd
+ */
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/pm_domain.h>
+#include <linux/soc/qcom/aoss-qmp.h>
+#include <dt-bindings/power/qcom-aoss-qmp.h>
+struct qmp_pd {
+ struct qmp *qmp;
+ struct generic_pm_domain pd;
+ const char *name;
+#define to_qmp_pd_resource(res) container_of(res, struct qmp_pd, pd)
+struct qmp_pd_resource {
+ const char *name;
+ int (*on)(struct generic_pm_domain *domain);
+ int (*off)(struct generic_pm_domain *domain);
+static int qmp_pd_clock_toggle(struct qmp_pd *res, bool enable)
+ char buf[96];
+ size_t n;
+ n = snprintf(buf, sizeof(buf), "{class: clock, res: %s, val: %d}",
+ res->name, !!enable);
+ return qmp_send(res->qmp, buf, n);

I was trying to get QDSS working with these patches and found one issue
in qmp_send of qmp_pd_clock_toggle.

The third return value should be sizeof(buf) instead of n because n just
returns len as 33 and the below check in qmp send will always fail and
trigger WARN_ON's.

if (WARN_ON(len % sizeof(u32))) {
dev_err(qmp->dev, "message not 32-bit aligned\n");
return -EINVAL;

Also I observed that multiple "ucore will not ack channel" messages with
len being returned n instead of buf size.

One more thing is do we really require *WARN_ON and dev_err* both because it just spams the kernel logs, I think dev_err message is clear
enough to be able to understand the error condition.


QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation