[PATCH v9 5/8] interconnect: qcom: Add RPM communication

Georgi Djakov
2018-08-31T14:01:48Z

On some Qualcomm SoCs, there is a remote processor, which controls some of
the Network-On-Chip interconnect resources. Other CPUs express their needs
by communicating with this processor. Add a driver to handle communication
with this remote processor.

Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
Reviewed-by: Evan Green <evgreen@chromium.org>
---
.../bindings/interconnect/qcom-smd.txt | 32 +++++++
drivers/interconnect/qcom/Kconfig | 13 +++
drivers/interconnect/qcom/Makefile | 5 +
drivers/interconnect/qcom/smd-rpm.c | 91 +++++++++++++++++++
drivers/interconnect/qcom/smd-rpm.h | 15 +++
5 files changed, 156 insertions(+)
create mode 100644 Documentation/devicetree/bindings/interconnect/qcom-smd.txt
create mode 100644 drivers/interconnect/qcom/Kconfig
create mode 100644 drivers/interconnect/qcom/Makefile
create mode 100644 drivers/interconnect/qcom/smd-rpm.c
create mode 100644 drivers/interconnect/qcom/smd-rpm.h

diff --git a/Documentation/devicetree/bindings/interconnect/qcom-smd.txt b/Documentation/devicetree/bindings/interconnect/qcom-smd.txt
new file mode 100644
index 000000000000..2325167f6eaf
--- /dev/null
+++ b/Documentation/devicetree/bindings/interconnect/qcom-smd.txt
@@ -0,0 +1,32 @@
+Qualcomm SMD-RPM interconnect driver binding
+------------------------------------------------
+The RPM (Resource Power Manager) is a dedicated hardware engine
+for managing the shared SoC resources in order to keep the lowest
+power profile. It communicates with other hardware subsystems via
+the shared memory driver (SMD) back-end and accepts requests for
+various resources.
+
+Required properties :
+- compatible : shall contain only one of the following:
+ "qcom,interconnect-smd-rpm"
+
+Example:
+ smd {
+ compatible = "qcom,smd";
+
+ rpm {
+ interrupts = <GIC_SPI 168 IRQ_TYPE_EDGE_RISING>;
+ qcom,ipc = <&apcs 8 0>;
+ qcom,smd-edge = <15>;
+
+ rpm_requests {
+ compatible = "qcom,rpm-msm8916";
+ qcom,smd-channels = "rpm_requests";
+
+ interconnect-smd-rpm {
+ compatible = "qcom,interconnect-smd-rpm";
+ };
+
+ };
+ };
+ };
diff --git a/drivers/interconnect/qcom/Kconfig b/drivers/interconnect/qcom/Kconfig
new file mode 100644
index 000000000000..6146552fac86
--- /dev/null
+++ b/drivers/interconnect/qcom/Kconfig
@@ -0,0 +1,13 @@
+config INTERCONNECT_QCOM
+ bool "Qualcomm Network-on-Chip interconnect drivers"
+ depends on ARCH_QCOM
+ help
+ Support for Qualcomm's Network-on-Chip interconnect hardware.
+
+config INTERCONNECT_QCOM_SMD_RPM
+ tristate "Qualcomm SMD RPM interconnect driver"
+ depends on INTERCONNECT_QCOM
+ depends on QCOM_SMD_RPM
+ help
+ This is a driver for communicating interconnect related configuration
+ details with a remote processor (RPM) on Qualcomm platforms.
diff --git a/drivers/interconnect/qcom/Makefile b/drivers/interconnect/qcom/Makefile
new file mode 100644
index 000000000000..f4477ad22ba2
--- /dev/null
+++ b/drivers/interconnect/qcom/Makefile
@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0
+
+qnoc-smd-rpm-objs := smd-rpm.o
+
+obj-$(CONFIG_INTERCONNECT_QCOM_SMD_RPM) += qnoc-smd-rpm.o
diff --git a/drivers/interconnect/qcom/smd-rpm.c b/drivers/interconnect/qcom/smd-rpm.c
new file mode 100644
index 000000000000..48b7a2a6eb84
--- /dev/null
+++ b/drivers/interconnect/qcom/smd-rpm.c
@@ -0,0 +1,91 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * RPM over SMD communication wrapper for interconnects
+ *
+ * Copyright (C) 2018 Linaro Ltd
+ * Author: Georgi Djakov <georgi.djakov@linaro.org>
+ */
+
+#include <linux/interconnect-provider.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/soc/qcom/smd-rpm.h>
+#include "smd-rpm.h"
+
+#define RPM_KEY_BW 0x00007762
+
+static struct qcom_icc_rpm {
+ struct qcom_smd_rpm *rpm;
+} icc_rpm_smd;
+
+struct icc_rpm_smd_req {
+ __le32 key;
+ __le32 nbytes;
+ __le32 value;
+};
+
+bool qcom_icc_rpm_smd_available(void)
+{
+ if (!icc_rpm_smd.rpm)
+ return false;
+
+ return true;
+}
+EXPORT_SYMBOL_GPL(qcom_icc_rpm_smd_available);
+
+int qcom_icc_rpm_smd_send(int ctx, int rsc_type, int id, u32 val)
+{
+ struct icc_rpm_smd_req req = {
+ .key = cpu_to_le32(RPM_KEY_BW),
+ .nbytes = cpu_to_le32(sizeof(u32)),
+ .value = cpu_to_le32(val),
+ };
+
+ return qcom_rpm_smd_write(icc_rpm_smd.rpm, ctx, rsc_type, id, &req,
+ sizeof(req));
+}
+EXPORT_SYMBOL_GPL(qcom_icc_rpm_smd_send);
+
+static int qcom_icc_rpm_smd_probe(struct platform_device *pdev)
+{
+ icc_rpm_smd.rpm = dev_get_drvdata(pdev->dev.parent);
+ if (!icc_rpm_smd.rpm) {
+ dev_err(&pdev->dev, "unable to retrieve handle to RPM\n");
+ return -ENODEV;
+ }
+
+ return 0;
+}
+
+static const struct of_device_id qcom_icc_rpm_smd_dt_match[] = {
+ { .compatible = "qcom,interconnect-smd-rpm", },
+ { },
+};
+
+MODULE_DEVICE_TABLE(of, qcom_icc_rpm_smd_dt_match);
+
+static struct platform_driver qcom_interconnect_rpm_smd_driver = {
+ .driver = {
+ .name = "qcom-interconnect-smd-rpm",
+ .of_match_table = qcom_icc_rpm_smd_dt_match,
+ },
+ .probe = qcom_icc_rpm_smd_probe,
+};
+
+static int __init rpm_smd_interconnect_init(void)
+{
+ return platform_driver_register(&qcom_interconnect_rpm_smd_driver);
+}
+subsys_initcall(rpm_smd_interconnect_init);
+
+static void __exit rpm_smd_interconnect_exit(void)
+{
+ platform_driver_unregister(&qcom_interconnect_rpm_smd_driver);
+}
+module_exit(rpm_smd_interconnect_exit)
+
+MODULE_AUTHOR("Georgi Djakov <georgi.djakov@linaro.org>");
+MODULE_DESCRIPTION("Qualcomm SMD RPM interconnect driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/interconnect/qcom/smd-rpm.h b/drivers/interconnect/qcom/smd-rpm.h
new file mode 100644
index 000000000000..11c280eb86dc
--- /dev/null
+++ b/drivers/interconnect/qcom/smd-rpm.h
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2018, Linaro Ltd.
+ * Author: Georgi Djakov <georgi.djakov@linaro.org>
+ */
+
+#ifndef __DRIVERS_INTERCONNECT_QCOM_SMD_RPM_H
+#define __DRIVERS_INTERCONNECT_QCOM_SMD_RPM_H
+
+#include <linux/soc/qcom/smd-rpm.h>
+
+bool qcom_icc_rpm_smd_available(void);
+int qcom_icc_rpm_smd_send(int ctx, int rsc_type, int id, u32 val);
+
+#endif