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Message-Id: <1470738562-20026-2-git-send-email-narmstrong@baylibre.com>
Date: Tue, 9 Aug 2016 12:29:15 +0200
From: Neil Armstrong <narmstrong@...libre.com>
To: linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
sudeep.holla@....com
Cc: Neil Armstrong <narmstrong@...libre.com>,
linux-amlogic@...ts.infradead.org, khilman@...libre.com,
heiko@...ech.de, wxt@...k-chips.com, frank.wang@...k-chips.com
Subject: [RFC PATCH v3 1/8] firmware: Add a SCPI registry to handle multiple implementations
Signed-off-by: Neil Armstrong <narmstrong@...libre.com>
---
drivers/firmware/Kconfig | 4 ++
drivers/firmware/Makefile | 1 +
drivers/firmware/scpi.c | 94 +++++++++++++++++++++++++++++++++++++++++++
include/linux/scpi_protocol.h | 15 ++++++-
4 files changed, 113 insertions(+), 1 deletion(-)
create mode 100644 drivers/firmware/scpi.c
diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig
index 0e22f24..ff85511 100644
--- a/drivers/firmware/Kconfig
+++ b/drivers/firmware/Kconfig
@@ -8,9 +8,13 @@ menu "Firmware Drivers"
config ARM_PSCI_FW
bool
+config SCPI_FW
+ bool
+
config ARM_SCPI_PROTOCOL
tristate "ARM System Control and Power Interface (SCPI) Message Protocol"
depends on MAILBOX
+ select SCPI_FW
help
System Control and Power Interface (SCPI) Message Protocol is
defined for the purpose of communication between the Application
diff --git a/drivers/firmware/Makefile b/drivers/firmware/Makefile
index 44a59dc..968197f 100644
--- a/drivers/firmware/Makefile
+++ b/drivers/firmware/Makefile
@@ -2,6 +2,7 @@
# Makefile for the linux kernel.
#
obj-$(CONFIG_ARM_PSCI_FW) += psci.o
+obj-$(CONFIG_SCPI_FW) += scpi.o
obj-$(CONFIG_ARM_SCPI_PROTOCOL) += arm_scpi.o
obj-$(CONFIG_ARM_SCPI_POWER_DOMAIN) += scpi_pm_domain.o
obj-$(CONFIG_DMI) += dmi_scan.o
diff --git a/drivers/firmware/scpi.c b/drivers/firmware/scpi.c
new file mode 100644
index 0000000..87a559a
--- /dev/null
+++ b/drivers/firmware/scpi.c
@@ -0,0 +1,94 @@
+/*
+ * System Control and Power Interface (SCPI) Message Protocol registry
+ *
+ * SCPI Message Protocol is used between the System Control Processor(SCP)
+ * and the Application Processors(AP). The Message Handling Unit(MHU)
+ * provides a mechanism for inter-processor communication between SCP's
+ * Cortex M3 and AP.
+ *
+ * SCP offers control and management of the core/cluster power states,
+ * various power domain DVFS including the core/cluster, certain system
+ * clocks configuration, thermal sensors and many others.
+ *
+ * Copyright (C) 2015 ARM Ltd.
+ * Copyright (C) 2016 BayLibre, SAS.
+ * Author: Neil Armstrong <narmstrong@...libre.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/export.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/of.h>
+#include <linux/scpi_protocol.h>
+#include <linux/spinlock.h>
+
+static struct scpi_ops *g_ops;
+
+struct scpi_ops *get_scpi_ops(void)
+{
+ return g_ops;
+}
+EXPORT_SYMBOL_GPL(get_scpi_ops);
+
+int scpi_ops_register(struct scpi_ops *ops)
+{
+ if (!ops)
+ return -EINVAL;
+
+ if (g_ops)
+ return -EEXIST;
+
+ g_ops = ops;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(scpi_ops_register);
+
+void scpi_ops_unregister(struct scpi_ops *ops)
+{
+ if (g_ops == ops)
+ g_ops = NULL;
+}
+EXPORT_SYMBOL_GPL(scpi_ops_unregister);
+
+static void devm_scpi_ops_unregister(struct device *dev, void *res)
+{
+ scpi_ops_unregister(*(struct scpi_ops **)res);
+}
+
+int devm_scpi_ops_register(struct device *dev,
+ struct scpi_ops *ops)
+{
+ struct scpi_ops **rcops;
+ int ret;
+
+ rcops = devres_alloc(devm_scpi_ops_unregister, sizeof(*ops),
+ GFP_KERNEL);
+ if (!rcops)
+ return -ENOMEM;
+
+ ret = scpi_ops_register(ops);
+ if (!ret) {
+ *rcops = ops;
+ devres_add(dev, rcops);
+ } else
+ devres_free(rcops);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(devm_scpi_ops_register);
diff --git a/include/linux/scpi_protocol.h b/include/linux/scpi_protocol.h
index dc5f989..8e21e3a 100644
--- a/include/linux/scpi_protocol.h
+++ b/include/linux/scpi_protocol.h
@@ -74,8 +74,21 @@ struct scpi_ops {
int (*device_set_power_state)(u16, u8);
};
-#if IS_REACHABLE(CONFIG_ARM_SCPI_PROTOCOL)
+#if IS_REACHABLE(CONFIG_SCPI_FW)
struct scpi_ops *get_scpi_ops(void);
+int scpi_ops_register(struct scpi_ops *drv);
+void scpi_ops_unregister(struct scpi_ops *drv);
+int devm_scpi_ops_register(struct device *dev, struct scpi_ops *drv);
#else
static inline struct scpi_ops *get_scpi_ops(void) { return NULL; }
+
+static inline int scpi_ops_register(struct scpi_ops *drv) { return -ENOTSUPP; }
+
+static inline void scpi_ops_unregister(struct scpi_ops *drv) { }
+
+static inline int devm_scpi_ops_register(struct device *dev,
+ struct scpi_ops *drv)
+{
+ return -ENOTSUPP;
+}
#endif
--
2.7.0
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