summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorArnd Bergmann <arnd@arndb.de>2015-10-14 17:07:32 +0200
committerArnd Bergmann <arnd@arndb.de>2015-10-14 17:07:32 +0200
commitc049adc9fd2937562b4880bdc35b8303ff56d425 (patch)
treef75d32289b1053b3e65cb0e7d330079bee2c9a9b
parent273395f0c2973b96a35772f8aa3b65c25517a45d (diff)
parent68acc77a2d5197141ba376fd8872eccb43bfcd7d (diff)
Merge tag 'arm-scpi-for-v4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux into next/drivers
Merge "ARM System Control and Power Interface(SCPI) support" from Sudeep Holla It adds support for the following features provided by SCP firmware using different subsystems in Linux: 1. SCPI mailbox protocol driver which using mailbox framework 2. Clocks provided by SCP using clock framework 3. CPU DVFS(cpufreq) using existing arm-big-little driver 4. SCPI based sensors including temperature sensors * tag 'arm-scpi-for-v4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux: hwmon: Support thermal zones registration for SCP temperature sensors hwmon: Support sensors exported via ARM SCP interface firmware: arm_scpi: Extend to support sensors Documentation: add DT bindings for ARM SCPI sensors cpufreq: arm_big_little: add SCPI interface driver clk: scpi: add support for cpufreq virtual device clk: add support for clocks provided by SCP(System Control Processor) firmware: add support for ARM System Control and Power Interface(SCPI) protocol Documentation: add DT binding for ARM System Control and Power Interface(SCPI) protocol
-rw-r--r--Documentation/devicetree/bindings/arm/arm,scpi.txt188
-rw-r--r--Documentation/hwmon/scpi-hwmon33
-rw-r--r--MAINTAINERS10
-rw-r--r--drivers/clk/Kconfig10
-rw-r--r--drivers/clk/Makefile1
-rw-r--r--drivers/clk/clk-scpi.c325
-rw-r--r--drivers/cpufreq/Kconfig.arm10
-rw-r--r--drivers/cpufreq/Makefile1
-rw-r--r--drivers/cpufreq/scpi-cpufreq.c124
-rw-r--r--drivers/firmware/Kconfig19
-rw-r--r--drivers/firmware/Makefile1
-rw-r--r--drivers/firmware/arm_scpi.c771
-rw-r--r--drivers/hwmon/Kconfig8
-rw-r--r--drivers/hwmon/Makefile1
-rw-r--r--drivers/hwmon/scpi-hwmon.c288
-rw-r--r--include/linux/scpi_protocol.h78
16 files changed, 1868 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/arm/arm,scpi.txt b/Documentation/devicetree/bindings/arm/arm,scpi.txt
new file mode 100644
index 000000000000..86302de67c2c
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/arm,scpi.txt
@@ -0,0 +1,188 @@
+System Control and Power Interface (SCPI) Message Protocol
+----------------------------------------------------------
+
+Firmware implementing the SCPI described in ARM document number ARM DUI 0922B
+("ARM Compute Subsystem SCP: Message Interface Protocols")[0] can be used
+by Linux to initiate various system control and power operations.
+
+Required properties:
+
+- compatible : should be "arm,scpi"
+- mboxes: List of phandle and mailbox channel specifiers
+ All the channels reserved by remote SCP firmware for use by
+ SCPI message protocol should be specified in any order
+- shmem : List of phandle pointing to the shared memory(SHM) area between the
+ processors using these mailboxes for IPC, one for each mailbox
+ SHM can be any memory reserved for the purpose of this communication
+ between the processors.
+
+See Documentation/devicetree/bindings/mailbox/mailbox.txt
+for more details about the generic mailbox controller and
+client driver bindings.
+
+Clock bindings for the clocks based on SCPI Message Protocol
+------------------------------------------------------------
+
+This binding uses the common clock binding[1].
+
+Container Node
+==============
+Required properties:
+- compatible : should be "arm,scpi-clocks"
+ All the clocks provided by SCP firmware via SCPI message
+ protocol much be listed as sub-nodes under this node.
+
+Sub-nodes
+=========
+Required properties:
+- compatible : shall include one of the following
+ "arm,scpi-dvfs-clocks" - all the clocks that are variable and index based.
+ These clocks don't provide an entire range of values between the
+ limits but only discrete points within the range. The firmware
+ provides the mapping for each such operating frequency and the
+ index associated with it. The firmware also manages the
+ voltage scaling appropriately with the clock scaling.
+ "arm,scpi-variable-clocks" - all the clocks that are variable and provide full
+ range within the specified range. The firmware provides the
+ range of values within a specified range.
+
+Other required properties for all clocks(all from common clock binding):
+- #clock-cells : Should be 1. Contains the Clock ID value used by SCPI commands.
+- clock-output-names : shall be the corresponding names of the outputs.
+- clock-indices: The identifying number for the clocks(i.e.clock_id) in the
+ node. It can be non linear and hence provide the mapping of identifiers
+ into the clock-output-names array.
+
+SRAM and Shared Memory for SCPI
+-------------------------------
+
+A small area of SRAM is reserved for SCPI communication between application
+processors and SCP.
+
+Required properties:
+- compatible : should be "arm,juno-sram-ns" for Non-secure SRAM on Juno
+
+The rest of the properties should follow the generic mmio-sram description
+found in ../../misc/sysram.txt
+
+Each sub-node represents the reserved area for SCPI.
+
+Required sub-node properties:
+- reg : The base offset and size of the reserved area with the SRAM
+- compatible : should be "arm,juno-scp-shmem" for Non-secure SRAM based
+ shared memory on Juno platforms
+
+Sensor bindings for the sensors based on SCPI Message Protocol
+--------------------------------------------------------------
+SCPI provides an API to access the various sensors on the SoC.
+
+Required properties:
+- compatible : should be "arm,scpi-sensors".
+- #thermal-sensor-cells: should be set to 1. This property follows the
+ thermal device tree bindings[2].
+
+ Valid cell values are raw identifiers (Sensor
+ ID) as used by the firmware. Refer to
+ platform documentation for your
+ implementation for the IDs to use. For Juno
+ R0 and Juno R1 refer to [3].
+
+[0] http://infocenter.arm.com/help/topic/com.arm.doc.dui0922b/index.html
+[1] Documentation/devicetree/bindings/clock/clock-bindings.txt
+[2] Documentation/devicetree/bindings/thermal/thermal.txt
+[3] http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0922b/apas03s22.html
+
+Example:
+
+sram: sram@50000000 {
+ compatible = "arm,juno-sram-ns", "mmio-sram";
+ reg = <0x0 0x50000000 0x0 0x10000>;
+
+ #address-cells = <1>;
+ #size-cells = <1>;
+ ranges = <0 0x0 0x50000000 0x10000>;
+
+ cpu_scp_lpri: scp-shmem@0 {
+ compatible = "arm,juno-scp-shmem";
+ reg = <0x0 0x200>;
+ };
+
+ cpu_scp_hpri: scp-shmem@200 {
+ compatible = "arm,juno-scp-shmem";
+ reg = <0x200 0x200>;
+ };
+};
+
+mailbox: mailbox0@40000000 {
+ ....
+ #mbox-cells = <1>;
+};
+
+scpi_protocol: scpi@2e000000 {
+ compatible = "arm,scpi";
+ mboxes = <&mailbox 0 &mailbox 1>;
+ shmem = <&cpu_scp_lpri &cpu_scp_hpri>;
+
+ clocks {
+ compatible = "arm,scpi-clocks";
+
+ scpi_dvfs: scpi_clocks@0 {
+ compatible = "arm,scpi-dvfs-clocks";
+ #clock-cells = <1>;
+ clock-indices = <0>, <1>, <2>;
+ clock-output-names = "atlclk", "aplclk","gpuclk";
+ };
+ scpi_clk: scpi_clocks@3 {
+ compatible = "arm,scpi-variable-clocks";
+ #clock-cells = <1>;
+ clock-indices = <3>, <4>;
+ clock-output-names = "pxlclk0", "pxlclk1";
+ };
+ };
+
+ scpi_sensors0: sensors {
+ compatible = "arm,scpi-sensors";
+ #thermal-sensor-cells = <1>;
+ };
+};
+
+cpu@0 {
+ ...
+ reg = <0 0>;
+ clocks = <&scpi_dvfs 0>;
+};
+
+hdlcd@7ff60000 {
+ ...
+ reg = <0 0x7ff60000 0 0x1000>;
+ clocks = <&scpi_clk 4>;
+};
+
+thermal-zones {
+ soc_thermal {
+ polling-delay-passive = <100>;
+ polling-delay = <1000>;
+
+ /* sensor ID */
+ thermal-sensors = <&scpi_sensors0 3>;
+ ...
+ };
+};
+
+In the above example, the #clock-cells is set to 1 as required.
+scpi_dvfs has 3 output clocks namely: atlclk, aplclk, and gpuclk with 0,
+1 and 2 as clock-indices. scpi_clk has 2 output clocks namely: pxlclk0
+and pxlclk1 with 3 and 4 as clock-indices.
+
+The first consumer in the example is cpu@0 and it has '0' as the clock
+specifier which points to the first entry in the output clocks of
+scpi_dvfs i.e. "atlclk".
+
+Similarly the second example is hdlcd@7ff60000 and it has pxlclk1 as input
+clock. '4' in the clock specifier here points to the second entry
+in the output clocks of scpi_clocks i.e. "pxlclk1"
+
+The thermal-sensors property in the soc_thermal node uses the
+temperature sensor provided by SCP firmware to setup a thermal
+zone. The ID "3" is the sensor identifier for the temperature sensor
+as used by the firmware.
diff --git a/Documentation/hwmon/scpi-hwmon b/Documentation/hwmon/scpi-hwmon
new file mode 100644
index 000000000000..4cfcdf2d5eab
--- /dev/null
+++ b/Documentation/hwmon/scpi-hwmon
@@ -0,0 +1,33 @@
+Kernel driver scpi-hwmon
+========================
+
+Supported chips:
+ * Chips based on ARM System Control Processor Interface
+ Addresses scanned: -
+ Datasheet: http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0922b/index.html
+
+Author: Punit Agrawal <punit.agrawal@arm.com>
+
+Description
+-----------
+
+This driver supports hardware monitoring for SoC's based on the ARM
+System Control Processor (SCP) implementing the System Control
+Processor Interface (SCPI). The following sensor types are supported
+by the SCP -
+
+ * temperature
+ * voltage
+ * current
+ * power
+
+The SCP interface provides an API to query the available sensors and
+their values which are then exported to userspace by this driver.
+
+Usage Notes
+-----------
+
+The driver relies on device tree node to indicate the presence of SCPI
+support in the kernel. See
+Documentation/devicetree/bindings/arm/arm,scpi.txt for details of the
+devicetree node. \ No newline at end of file
diff --git a/MAINTAINERS b/MAINTAINERS
index 797236befd27..960d31031e4b 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -9153,6 +9153,16 @@ W: http://www.sunplus.com
S: Supported
F: arch/score/
+SYSTEM CONTROL & POWER INTERFACE (SCPI) Message Protocol drivers
+M: Sudeep Holla <sudeep.holla@arm.com>
+L: linux-arm-kernel@lists.infradead.org
+S: Maintained
+F: Documentation/devicetree/bindings/arm/arm,scpi.txt
+F: drivers/clk/clk-scpi.c
+F: drivers/cpufreq/scpi-cpufreq.c
+F: drivers/firmware/arm_scpi.c
+F: include/linux/scpi_protocol.h
+
SCSI CDROM DRIVER
M: Jens Axboe <axboe@kernel.dk>
L: linux-scsi@vger.kernel.org
diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
index 42f7120ca9ce..4aec54b90331 100644
--- a/drivers/clk/Kconfig
+++ b/drivers/clk/Kconfig
@@ -59,6 +59,16 @@ config COMMON_CLK_RK808
clocked at 32KHz each. Clkout1 is always on, Clkout2 can off
by control register.
+config COMMON_CLK_SCPI
+ tristate "Clock driver controlled via SCPI interface"
+ depends on ARM_SCPI_PROTOCOL || COMPILE_TEST
+ ---help---
+ This driver provides support for clocks that are controlled
+ by firmware that implements the SCPI interface.
+
+ This driver uses SCPI Message Protocol to interact with the
+ firmware providing all the clock controls.
+
config COMMON_CLK_SI5351
tristate "Clock driver for SiLabs 5351A/B/C"
depends on I2C
diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index d08b3e5985be..a381431bd950 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -36,6 +36,7 @@ obj-$(CONFIG_COMMON_CLK_PALMAS) += clk-palmas.o
obj-$(CONFIG_CLK_QORIQ) += clk-qoriq.o
obj-$(CONFIG_COMMON_CLK_RK808) += clk-rk808.o
obj-$(CONFIG_COMMON_CLK_S2MPS11) += clk-s2mps11.o
+obj-$(CONFIG_COMMON_CLK_SCPI) += clk-scpi.o
obj-$(CONFIG_COMMON_CLK_SI5351) += clk-si5351.o
obj-$(CONFIG_COMMON_CLK_SI570) += clk-si570.o
obj-$(CONFIG_COMMON_CLK_CDCE925) += clk-cdce925.o
diff --git a/drivers/clk/clk-scpi.c b/drivers/clk/clk-scpi.c
new file mode 100644
index 000000000000..0b501a9fef92
--- /dev/null
+++ b/drivers/clk/clk-scpi.c
@@ -0,0 +1,325 @@
+/*
+ * System Control and Power Interface (SCPI) Protocol based clock driver
+ *
+ * Copyright (C) 2015 ARM Ltd.
+ *
+ * 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/clk-provider.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/of.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/scpi_protocol.h>
+
+struct scpi_clk {
+ u32 id;
+ struct clk_hw hw;
+ struct scpi_dvfs_info *info;
+ struct scpi_ops *scpi_ops;
+};
+
+#define to_scpi_clk(clk) container_of(clk, struct scpi_clk, hw)
+
+static struct platform_device *cpufreq_dev;
+
+static unsigned long scpi_clk_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct scpi_clk *clk = to_scpi_clk(hw);
+
+ return clk->scpi_ops->clk_get_val(clk->id);
+}
+
+static long scpi_clk_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *parent_rate)
+{
+ /*
+ * We can't figure out what rate it will be, so just return the
+ * rate back to the caller. scpi_clk_recalc_rate() will be called
+ * after the rate is set and we'll know what rate the clock is
+ * running at then.
+ */
+ return rate;
+}
+
+static int scpi_clk_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct scpi_clk *clk = to_scpi_clk(hw);
+
+ return clk->scpi_ops->clk_set_val(clk->id, rate);
+}
+
+static const struct clk_ops scpi_clk_ops = {
+ .recalc_rate = scpi_clk_recalc_rate,
+ .round_rate = scpi_clk_round_rate,
+ .set_rate = scpi_clk_set_rate,
+};
+
+/* find closest match to given frequency in OPP table */
+static int __scpi_dvfs_round_rate(struct scpi_clk *clk, unsigned long rate)
+{
+ int idx;
+ u32 fmin = 0, fmax = ~0, ftmp;
+ const struct scpi_opp *opp = clk->info->opps;
+
+ for (idx = 0; idx < clk->info->count; idx++, opp++) {
+ ftmp = opp->freq;
+ if (ftmp >= (u32)rate) {
+ if (ftmp <= fmax)
+ fmax = ftmp;
+ break;
+ } else if (ftmp >= fmin) {
+ fmin = ftmp;
+ }
+ }
+ return fmax != ~0 ? fmax : fmin;
+}
+
+static unsigned long scpi_dvfs_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct scpi_clk *clk = to_scpi_clk(hw);
+ int idx = clk->scpi_ops->dvfs_get_idx(clk->id);
+ const struct scpi_opp *opp;
+
+ if (idx < 0)
+ return 0;
+
+ opp = clk->info->opps + idx;
+ return opp->freq;
+}
+
+static long scpi_dvfs_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *parent_rate)
+{
+ struct scpi_clk *clk = to_scpi_clk(hw);
+
+ return __scpi_dvfs_round_rate(clk, rate);
+}
+
+static int __scpi_find_dvfs_index(struct scpi_clk *clk, unsigned long rate)
+{
+ int idx, max_opp = clk->info->count;
+ const struct scpi_opp *opp = clk->info->opps;
+
+ for (idx = 0; idx < max_opp; idx++, opp++)
+ if (opp->freq == rate)
+ return idx;
+ return -EINVAL;
+}
+
+static int scpi_dvfs_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct scpi_clk *clk = to_scpi_clk(hw);
+ int ret = __scpi_find_dvfs_index(clk, rate);
+
+ if (ret < 0)
+ return ret;
+ return clk->scpi_ops->dvfs_set_idx(clk->id, (u8)ret);
+}
+
+static const struct clk_ops scpi_dvfs_ops = {
+ .recalc_rate = scpi_dvfs_recalc_rate,
+ .round_rate = scpi_dvfs_round_rate,
+ .set_rate = scpi_dvfs_set_rate,
+};
+
+static const struct of_device_id scpi_clk_match[] = {
+ { .compatible = "arm,scpi-dvfs-clocks", .data = &scpi_dvfs_ops, },
+ { .compatible = "arm,scpi-variable-clocks", .data = &scpi_clk_ops, },
+ {}
+};
+
+static struct clk *
+scpi_clk_ops_init(struct device *dev, const struct of_device_id *match,
+ struct scpi_clk *sclk, const char *name)
+{
+ struct clk_init_data init;
+ struct clk *clk;
+ unsigned long min = 0, max = 0;
+
+ init.name = name;
+ init.flags = CLK_IS_ROOT;
+ init.num_parents = 0;
+ init.ops = match->data;
+ sclk->hw.init = &init;
+ sclk->scpi_ops = get_scpi_ops();
+
+ if (init.ops == &scpi_dvfs_ops) {
+ sclk->info = sclk->scpi_ops->dvfs_get_info(sclk->id);
+ if (IS_ERR(sclk->info))
+ return NULL;
+ } else if (init.ops == &scpi_clk_ops) {
+ if (sclk->scpi_ops->clk_get_range(sclk->id, &min, &max) || !max)
+ return NULL;
+ } else {
+ return NULL;
+ }
+
+ clk = devm_clk_register(dev, &sclk->hw);
+ if (!IS_ERR(clk) && max)
+ clk_hw_set_rate_range(&sclk->hw, min, max);
+ return clk;
+}
+
+struct scpi_clk_data {
+ struct scpi_clk **clk;
+ unsigned int clk_num;
+};
+
+static struct clk *
+scpi_of_clk_src_get(struct of_phandle_args *clkspec, void *data)
+{
+ struct scpi_clk *sclk;
+ struct scpi_clk_data *clk_data = data;
+ unsigned int idx = clkspec->args[0], count;
+
+ for (count = 0; count < clk_data->clk_num; count++) {
+ sclk = clk_data->clk[count];
+ if (idx == sclk->id)
+ return sclk->hw.clk;
+ }
+
+ return ERR_PTR(-EINVAL);
+}
+
+static int scpi_clk_add(struct device *dev, struct device_node *np,
+ const struct of_device_id *match)
+{
+ struct clk **clks;
+ int idx, count;
+ struct scpi_clk_data *clk_data;
+
+ count = of_property_count_strings(np, "clock-output-names");
+ if (count < 0) {
+ dev_err(dev, "%s: invalid clock output count\n", np->name);
+ return -EINVAL;
+ }
+
+ clk_data = devm_kmalloc(dev, sizeof(*clk_data), GFP_KERNEL);
+ if (!clk_data)
+ return -ENOMEM;
+
+ clk_data->clk_num = count;
+ clk_data->clk = devm_kcalloc(dev, count, sizeof(*clk_data->clk),
+ GFP_KERNEL);
+ if (!clk_data->clk)
+ return -ENOMEM;
+
+ clks = devm_kcalloc(dev, count, sizeof(*clks), GFP_KERNEL);
+ if (!clks)
+ return -ENOMEM;
+
+ for (idx = 0; idx < count; idx++) {
+ struct scpi_clk *sclk;
+ const char *name;
+ u32 val;
+
+ sclk = devm_kzalloc(dev, sizeof(*sclk), GFP_KERNEL);
+ if (!sclk)
+ return -ENOMEM;
+
+ if (of_property_read_string_index(np, "clock-output-names",
+ idx, &name)) {
+ dev_err(dev, "invalid clock name @ %s\n", np->name);
+ return -EINVAL;
+ }
+
+ if (of_property_read_u32_index(np, "clock-indices",
+ idx, &val)) {
+ dev_err(dev, "invalid clock index @ %s\n", np->name);
+ return -EINVAL;
+ }
+
+ sclk->id = val;
+
+ clks[idx] = scpi_clk_ops_init(dev, match, sclk, name);
+ if (IS_ERR_OR_NULL(clks[idx]))
+ dev_err(dev, "failed to register clock '%s'\n", name);
+ else
+ dev_dbg(dev, "Registered clock '%s'\n", name);
+ clk_data->clk[idx] = sclk;
+ }
+
+ return of_clk_add_provider(np, scpi_of_clk_src_get, clk_data);
+}
+
+static int scpi_clocks_remove(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *child, *np = dev->of_node;
+
+ if (cpufreq_dev) {
+ platform_device_unregister(cpufreq_dev);
+ cpufreq_dev = NULL;
+ }
+
+ for_each_available_child_of_node(np, child)
+ of_clk_del_provider(np);
+ return 0;
+}
+
+static int scpi_clocks_probe(struct platform_device *pdev)
+{
+ int ret;
+ struct device *dev = &pdev->dev;
+ struct device_node *child, *np = dev->of_node;
+ const struct of_device_id *match;
+
+ if (!get_scpi_ops())
+ return -ENXIO;
+
+ for_each_available_child_of_node(np, child) {
+ match = of_match_node(scpi_clk_match, child);
+ if (!match)
+ continue;
+ ret = scpi_clk_add(dev, child, match);
+ if (ret) {
+ scpi_clocks_remove(pdev);
+ return ret;
+ }
+ }
+ /* Add the virtual cpufreq device */
+ cpufreq_dev = platform_device_register_simple("scpi-cpufreq",
+ -1, NULL, 0);
+ if (!cpufreq_dev)
+ pr_warn("unable to register cpufreq device");
+
+ return 0;
+}
+
+static const struct of_device_id scpi_clocks_ids[] = {
+ { .compatible = "arm,scpi-clocks", },
+ {}
+};
+MODULE_DEVICE_TABLE(of, scpi_clocks_ids);
+
+static struct platform_driver scpi_clocks_driver = {
+ .driver = {
+ .name = "scpi_clocks",
+ .of_match_table = scpi_clocks_ids,
+ },
+ .probe = scpi_clocks_probe,
+ .remove = scpi_clocks_remove,
+};
+module_platform_driver(scpi_clocks_driver);
+
+MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
+MODULE_DESCRIPTION("ARM SCPI clock driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm
index cd0391e46c6d..c737f7359974 100644
--- a/drivers/cpufreq/Kconfig.arm
+++ b/drivers/cpufreq/Kconfig.arm
@@ -199,6 +199,16 @@ config ARM_SA1100_CPUFREQ
config ARM_SA1110_CPUFREQ
bool
+config ARM_SCPI_CPUFREQ
+ tristate "SCPI based CPUfreq driver"
+ depends on ARM_BIG_LITTLE_CPUFREQ && ARM_SCPI_PROTOCOL
+ help
+ This adds the CPUfreq driver support for ARM big.LITTLE platforms
+ using SCPI protocol for CPU power management.
+
+ This driver uses SCPI Message Protocol driver to interact with the
+ firmware providing the CPU DVFS functionality.
+
config ARM_SPEAR_CPUFREQ
bool "SPEAr CPUFreq support"
depends on PLAT_SPEAR
diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile
index 41340384f11f..ccfaa4c68a9a 100644
--- a/drivers/cpufreq/Makefile
+++ b/drivers/cpufreq/Makefile
@@ -72,6 +72,7 @@ obj-$(CONFIG_ARM_S3C64XX_CPUFREQ) += s3c64xx-cpufreq.o
obj-$(CONFIG_ARM_S5PV210_CPUFREQ) += s5pv210-cpufreq.o
obj-$(CONFIG_ARM_SA1100_CPUFREQ) += sa1100-cpufreq.o
obj-$(CONFIG_ARM_SA1110_CPUFREQ) += sa1110-cpufreq.o
+obj-$(CONFIG_ARM_SCPI_CPUFREQ) += scpi-cpufreq.o
obj-$(CONFIG_ARM_SPEAR_CPUFREQ) += spear-cpufreq.o
obj-$(CONFIG_ARM_TEGRA20_CPUFREQ) += tegra20-cpufreq.o
obj-$(CONFIG_ARM_TEGRA124_CPUFREQ) += tegra124-cpufreq.o
diff --git a/drivers/cpufreq/scpi-cpufreq.c b/drivers/cpufreq/scpi-cpufreq.c
new file mode 100644
index 000000000000..2c3b16fd3a01
--- /dev/null
+++ b/drivers/cpufreq/scpi-cpufreq.c
@@ -0,0 +1,124 @@
+/*
+ * System Control and Power Interface (SCPI) based CPUFreq Interface driver
+ *
+ * It provides necessary ops to arm_big_little cpufreq driver.
+ *
+ * Copyright (C) 2015 ARM Ltd.
+ * Sudeep Holla <sudeep.holla@arm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/cpufreq.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pm_opp.h>
+#include <linux/scpi_protocol.h>
+#include <linux/types.h>
+
+#include "arm_big_little.h"
+
+static struct scpi_ops *scpi_ops;
+
+static struct scpi_dvfs_info *scpi_get_dvfs_info(struct device *cpu_dev)
+{
+ u8 domain = topology_physical_package_id(cpu_dev->id);
+
+ if (domain < 0)
+ return ERR_PTR(-EINVAL);
+ return scpi_ops->dvfs_get_info(domain);
+}
+
+static int scpi_opp_table_ops(struct device *cpu_dev, bool remove)
+{
+ int idx, ret = 0;
+ struct scpi_opp *opp;
+ struct scpi_dvfs_info *info = scpi_get_dvfs_info(cpu_dev);
+
+ if (IS_ERR(info))
+ return PTR_ERR(info);
+
+ if (!info->opps)
+ return -EIO;
+
+ for (opp = info->opps, idx = 0; idx < info->count; idx++, opp++) {
+ if (remove)
+ dev_pm_opp_remove(cpu_dev, opp->freq);
+ else
+ ret = dev_pm_opp_add(cpu_dev, opp->freq,
+ opp->m_volt * 1000);
+ if (ret) {
+ dev_warn(cpu_dev, "failed to add opp %uHz %umV\n",
+ opp->freq, opp->m_volt);
+ while (idx-- > 0)
+ dev_pm_opp_remove(cpu_dev, (--opp)->freq);
+ return ret;
+ }
+ }
+ return ret;
+}
+
+static int scpi_get_transition_latency(struct device *cpu_dev)
+{
+ struct scpi_dvfs_info *info = scpi_get_dvfs_info(cpu_dev);
+
+ if (IS_ERR(info))
+ return PTR_ERR(info);
+ return info->latency;
+}
+
+static int scpi_init_opp_table(struct device *cpu_dev)
+{
+ return scpi_opp_table_ops(cpu_dev, false);
+}
+
+static void scpi_free_opp_table(struct device *cpu_dev)
+{
+ scpi_opp_table_ops(cpu_dev, true);
+}
+
+static struct cpufreq_arm_bL_ops scpi_cpufreq_ops = {
+ .name = "scpi",
+ .get_transition_latency = scpi_get_transition_latency,
+ .init_opp_table = scpi_init_opp_table,
+ .free_opp_table = scpi_free_opp_table,
+};
+
+static int scpi_cpufreq_probe(struct platform_device *pdev)
+{
+ scpi_ops = get_scpi_ops();
+ if (!scpi_ops)
+ return -EIO;
+
+ return bL_cpufreq_register(&scpi_cpufreq_ops);
+}
+
+static int scpi_cpufreq_remove(struct platform_device *pdev)
+{
+ bL_cpufreq_unregister(&scpi_cpufreq_ops);
+ scpi_ops = NULL;
+ return 0;
+}
+
+static struct platform_driver scpi_cpufreq_platdrv = {
+ .driver = {
+ .name = "scpi-cpufreq",
+ .owner = THIS_MODULE,
+ },
+ .probe = scpi_cpufreq_probe,
+ .remove = scpi_cpufreq_remove,
+};
+module_platform_driver(scpi_cpufreq_platdrv);
+
+MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
+MODULE_DESCRIPTION("ARM SCPI CPUFreq interface driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig
index 665efca59487..d00c6d338cc3 100644
--- a/drivers/firmware/Kconfig
+++ b/drivers/firmware/Kconfig
@@ -8,6 +8,25 @@ menu "Firmware Drivers"
config ARM_PSCI_FW
bool
+config ARM_SCPI_PROTOCOL
+ tristate "ARM System Control and Power Interface (SCPI) Message Protocol"
+ depends on ARM_MHU
+ help
+ System Control and Power Interface (SCPI) Message Protocol is
+ defined for the purpose of communication between the Application
+ Cores(AP) and the System Control Processor(SCP). The MHU peripheral
+ provides a mechanism for inter-processor communication between SCP
+ and AP.
+
+ SCP controls most of the power managament on the Application
+ Processors. It 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.
+
+ This protocol library provides interface for all the client drivers
+ making use of the features offered by the SCP.
+
config EDD
tristate "BIOS Enhanced Disk Drive calls determine boot disk"
depends on X86
diff --git a/drivers/firmware/Makefile b/drivers/firmware/Makefile
index 2ee83474a3c1..b8a521741418 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_ARM_SCPI_PROTOCOL) += arm_scpi.o
obj-$(CONFIG_DMI) += dmi_scan.o
obj-$(CONFIG_DMI_SYSFS) += dmi-sysfs.o
obj-$(CONFIG_EDD) += edd.o
diff --git a/drivers/firmware/arm_scpi.c b/drivers/firmware/arm_scpi.c
new file mode 100644
index 000000000000..6174db80c663
--- /dev/null
+++ b/drivers/firmware/arm_scpi.c
@@ -0,0 +1,771 @@
+/*
+ * System Control and Power Interface (SCPI) Message Protocol driver
+ *
+ * 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.
+ *
+ * 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/>.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/bitmap.h>
+#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/mailbox_client.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+#include <linux/printk.h>
+#include <linux/scpi_protocol.h>
+#include <linux/slab.h>
+#include <linux/sort.h>
+#include <linux/spinlock.h>
+
+#define CMD_ID_SHIFT 0
+#define CMD_ID_MASK 0x7f
+#define CMD_TOKEN_ID_SHIFT 8
+#define CMD_TOKEN_ID_MASK 0xff
+#define CMD_DATA_SIZE_SHIFT 16
+#define CMD_DATA_SIZE_MASK 0x1ff
+#define PACK_SCPI_CMD(cmd_id, tx_sz) \
+ ((((cmd_id) & CMD_ID_MASK) << CMD_ID_SHIFT) | \
+ (((tx_sz) & CMD_DATA_SIZE_MASK) << CMD_DATA_SIZE_SHIFT))
+#define ADD_SCPI_TOKEN(cmd, token) \
+ ((cmd) |= (((token) & CMD_TOKEN_ID_MASK) << CMD_TOKEN_ID_SHIFT))
+
+#define CMD_SIZE(cmd) (((cmd) >> CMD_DATA_SIZE_SHIFT) & CMD_DATA_SIZE_MASK)
+#define CMD_UNIQ_MASK (CMD_TOKEN_ID_MASK << CMD_TOKEN_ID_SHIFT | CMD_ID_MASK)
+#define CMD_XTRACT_UNIQ(cmd) ((cmd) & CMD_UNIQ_MASK)
+
+#define SCPI_SLOT 0
+
+#define MAX_DVFS_DOMAINS 8
+#define MAX_DVFS_OPPS 8
+#define DVFS_LATENCY(hdr) (le32_to_cpu(hdr) >> 16)
+#define DVFS_OPP_COUNT(hdr) ((le32_to_cpu(hdr) >> 8) & 0xff)
+
+#define PROTOCOL_REV_MINOR_BITS 16
+#define PROTOCOL_REV_MINOR_MASK ((1U << PROTOCOL_REV_MINOR_BITS) - 1)
+#define PROTOCOL_REV_MAJOR(x) ((x) >> PROTOCOL_REV_MINOR_BITS)
+#define PROTOCOL_REV_MINOR(x) ((x) & PROTOCOL_REV_MINOR_MASK)
+
+#define FW_REV_MAJOR_BITS 24
+#define FW_REV_MINOR_BITS 16
+#define FW_REV_PATCH_MASK ((1U << FW_REV_MINOR_BITS) - 1)
+#define FW_REV_MINOR_MASK ((1U << FW_REV_MAJOR_BITS) - 1)
+#define FW_REV_MAJOR(x) ((x) >> FW_REV_MAJOR_BITS)
+#define FW_REV_MINOR(x) (((x) & FW_REV_MINOR_MASK) >> FW_REV_MINOR_BITS)
+#define FW_REV_PATCH(x) ((x) & FW_REV_PATCH_MASK)
+
+#define MAX_RX_TIMEOUT (msecs_to_jiffies(20))
+
+enum scpi_error_codes {
+ SCPI_SUCCESS = 0, /* Success */
+ SCPI_ERR_PARAM = 1, /* Invalid parameter(s) */
+ SCPI_ERR_ALIGN = 2, /* Invalid alignment */
+ SCPI_ERR_SIZE = 3, /* Invalid size */
+ SCPI_ERR_HANDLER = 4, /* Invalid handler/callback */
+ SCPI_ERR_ACCESS = 5, /* Invalid access/permission denied */
+ SCPI_ERR_RANGE = 6, /* Value out of range */
+ SCPI_ERR_TIMEOUT = 7, /* Timeout has occurred */
+ SCPI_ERR_NOMEM = 8, /* Invalid memory area or pointer */
+ SCPI_ERR_PWRSTATE = 9, /* Invalid power state */
+ SCPI_ERR_SUPPORT = 10, /* Not supported or disabled */
+ SCPI_ERR_DEVICE = 11, /* Device error */
+ SCPI_ERR_BUSY = 12, /* Device busy */
+ SCPI_ERR_MAX
+};
+
+enum scpi_std_cmd {
+ SCPI_CMD_INVALID = 0x00,
+ SCPI_CMD_SCPI_READY = 0x01,
+ SCPI_CMD_SCPI_CAPABILITIES = 0x02,
+ SCPI_CMD_SET_CSS_PWR_STATE = 0x03,
+ SCPI_CMD_GET_CSS_PWR_STATE = 0x04,
+ SCPI_CMD_SET_SYS_PWR_STATE = 0x05,
+ SCPI_CMD_SET_CPU_TIMER = 0x06,
+ SCPI_CMD_CANCEL_CPU_TIMER = 0x07,
+ SCPI_CMD_DVFS_CAPABILITIES = 0x08,
+ SCPI_CMD_GET_DVFS_INFO = 0x09,
+ SCPI_CMD_SET_DVFS = 0x0a,
+ SCPI_CMD_GET_DVFS = 0x0b,
+ SCPI_CMD_GET_DVFS_STAT = 0x0c,
+ SCPI_CMD_CLOCK_CAPABILITIES = 0x0d,
+ SCPI_CMD_GET_CLOCK_INFO = 0x0e,
+ SCPI_CMD_SET_CLOCK_VALUE = 0x0f,
+ SCPI_CMD_GET_CLOCK_VALUE = 0x10,
+ SCPI_CMD_PSU_CAPABILITIES = 0x11,
+ SCPI_CMD_GET_PSU_INFO = 0x12,
+ SCPI_CMD_SET_PSU = 0x13,
+ SCPI_CMD_GET_PSU = 0x14,
+ SCPI_CMD_SENSOR_CAPABILITIES = 0x15,
+ SCPI_CMD_SENSOR_INFO = 0x16,
+ SCPI_CMD_SENSOR_VALUE = 0x17,
+ SCPI_CMD_SENSOR_CFG_PERIODIC = 0x18,
+ SCPI_CMD_SENSOR_CFG_BOUNDS = 0x19,
+ SCPI_CMD_SENSOR_ASYNC_VALUE = 0x1a,
+ SCPI_CMD_SET_DEVICE_PWR_STATE = 0x1b,
+ SCPI_CMD_GET_DEVICE_PWR_STATE = 0x1c,
+ SCPI_CMD_COUNT
+};
+
+struct scpi_xfer {
+ u32 slot; /* has to be first element */
+ u32 cmd;
+ u32 status;
+ const void *tx_buf;
+ void *rx_buf;
+ unsigned int tx_len;
+ unsigned int rx_len;
+ struct list_head node;
+ struct completion done;
+};
+
+struct scpi_chan {
+ struct mbox_client cl;
+ struct mbox_chan *chan;
+ void __iomem *tx_payload;
+ void __iomem *rx_payload;
+ struct list_head rx_pending;
+ struct list_head xfers_list;
+ struct scpi_xfer *xfers;
+ spinlock_t rx_lock; /* locking for the rx pending list */
+ struct mutex xfers_lock;
+ u8 token;
+};
+
+struct scpi_drvinfo {
+ u32 protocol_version;
+ u32 firmware_version;
+ int num_chans;
+ atomic_t next_chan;
+ struct scpi_ops *scpi_ops;
+ struct scpi_chan *channels;
+ struct scpi_dvfs_info *dvfs[MAX_DVFS_DOMAINS];
+};
+
+/*
+ * The SCP firmware only executes in little-endian mode, so any buffers
+ * shared through SCPI should have their contents converted to little-endian
+ */
+struct scpi_shared_mem {
+ __le32 command;
+ __le32 status;
+ u8 payload[0];
+} __packed;
+
+struct scp_capabilities {
+ __le32 protocol_version;
+ __le32 event_version;
+ __le32 platform_version;
+ __le32 commands[4];
+} __packed;
+
+struct clk_get_info {
+ __le16 id;
+ __le16 flags;
+ __le32 min_rate;
+ __le32 max_rate;
+ u8 name[20];
+} __packed;
+
+struct clk_get_value {
+ __le32 rate;
+} __packed;
+
+struct clk_set_value {
+ __le16 id;
+ __le16 reserved;
+ __le32 rate;
+} __packed;
+
+struct dvfs_info {
+ __le32 header;
+ struct {
+ __le32 freq;
+ __le32 m_volt;
+ } opps[MAX_DVFS_OPPS];
+} __packed;
+
+struct dvfs_get {
+ u8 index;
+} __packed;
+
+struct dvfs_set {
+ u8 domain;
+ u8 index;
+} __packed;
+
+struct sensor_capabilities {
+ __le16 sensors;
+} __packed;
+
+struct _scpi_sensor_info {
+ __le16 sensor_id;
+ u8 class;
+ u8 trigger_type;
+ char name[20];
+};
+
+struct sensor_value {
+ __le32 val;
+} __packed;
+
+static struct scpi_drvinfo *scpi_info;
+
+static int scpi_linux_errmap[SCPI_ERR_MAX] = {
+ /* better than switch case as long as return value is continuous */
+ 0, /* SCPI_SUCCESS */
+ -EINVAL, /* SCPI_ERR_PARAM */
+ -ENOEXEC, /* SCPI_ERR_ALIGN */
+ -EMSGSIZE, /* SCPI_ERR_SIZE */
+ -EINVAL, /* SCPI_ERR_HANDLER */
+ -EACCES, /* SCPI_ERR_ACCESS */
+ -ERANGE, /* SCPI_ERR_RANGE */
+ -ETIMEDOUT, /* SCPI_ERR_TIMEOUT */
+ -ENOMEM, /* SCPI_ERR_NOMEM */
+ -EINVAL, /* SCPI_ERR_PWRSTATE */
+ -EOPNOTSUPP, /* SCPI_ERR_SUPPORT */
+ -EIO, /* SCPI_ERR_DEVICE */
+ -EBUSY, /* SCPI_ERR_BUSY */
+};
+
+static inline int scpi_to_linux_errno(int errno)
+{
+ if (errno >= SCPI_SUCCESS && errno < SCPI_ERR_MAX)
+ return scpi_linux_errmap[errno];
+ return -EIO;
+}
+
+static void scpi_process_cmd(struct scpi_chan *ch, u32 cmd)
+{
+ unsigned long flags;
+ struct scpi_xfer *t, *match = NULL;
+
+ spin_lock_irqsave(&ch->rx_lock, flags);
+ if (list_empty(&ch->rx_pending)) {
+ spin_unlock_irqrestore(&ch->rx_lock, flags);
+ return;
+ }
+
+ list_for_each_entry(t, &ch->rx_pending, node)
+ if (CMD_XTRACT_UNIQ(t->cmd) == CMD_XTRACT_UNIQ(cmd)) {
+ list_del(&t->node);
+ match = t;
+ break;
+ }
+ /* check if wait_for_completion is in progress or timed-out */
+ if (match && !completion_done(&match->done)) {
+ struct scpi_shared_mem *mem = ch->rx_payload;
+ unsigned int len = min(match->rx_len, CMD_SIZE(cmd));
+
+ match->status = le32_to_cpu(mem->status);
+ memcpy_fromio(match->rx_buf, mem->payload, len);
+ if (match->rx_len > len)
+ memset(match->rx_buf + len, 0, match->rx_len - len);
+ complete(&match->done);
+ }
+ spin_unlock_irqrestore(&ch->rx_lock, flags);
+}
+
+static void scpi_handle_remote_msg(struct mbox_client *c, void *msg)
+{
+ struct scpi_chan *ch = container_of(c, struct scpi_chan, cl);
+ struct scpi_shared_mem *mem = ch->rx_payload;
+ u32 cmd = le32_to_cpu(mem->command);
+
+ scpi_process_cmd(ch, cmd);
+}
+
+static void scpi_tx_prepare(struct mbox_client *c, void *msg)
+{
+ unsigned long flags;
+ struct scpi_xfer *t = msg;
+ struct scpi_chan *ch = container_of(c, struct scpi_chan, cl);
+ struct scpi_shared_mem *mem = (struct scpi_shared_mem *)ch->tx_payload;
+
+ if (t->tx_buf)
+ memcpy_toio(mem->payload, t->tx_buf, t->tx_len);
+ if (t->rx_buf) {
+ if (!(++ch->token))
+ ++ch->token;
+ ADD_SCPI_TOKEN(t->cmd, ch->token);
+ spin_lock_irqsave(&ch->rx_lock, flags);
+ list_add_tail(&t->node, &ch->rx_pending);
+ spin_unlock_irqrestore(&ch->rx_lock, flags);
+ }
+ mem->command = cpu_to_le32(t->cmd);
+}
+
+static struct scpi_xfer *get_scpi_xfer(struct scpi_chan *ch)
+{
+ struct scpi_xfer *t;
+
+ mutex_lock(&ch->xfers_lock);
+ if (list_empty(&ch->xfers_list)) {
+ mutex_unlock(&ch->xfers_lock);
+ return NULL;
+ }
+ t = list_first_entry(&ch->xfers_list, struct scpi_xfer, node);
+ list_del(&t->node);
+ mutex_unlock(&ch->xfers_lock);
+ return t;
+}
+
+static void put_scpi_xfer(struct scpi_xfer *t, struct scpi_chan *ch)
+{
+ mutex_lock(&ch->xfers_lock);
+ list_add_tail(&t->node, &ch->xfers_list);
+ mutex_unlock(&ch->xfers_lock);
+}
+
+static int scpi_send_message(u8 cmd, void *tx_buf, unsigned int tx_len,
+ void *rx_buf, unsigned int rx_len)
+{
+ int ret;
+ u8 chan;
+ struct scpi_xfer *msg;
+ struct scpi_chan *scpi_chan;
+
+ chan = atomic_inc_return(&scpi_info->next_chan) % scpi_info->num_chans;
+ scpi_chan = scpi_info->channels + chan;
+
+ msg = get_scpi_xfer(scpi_chan);
+ if (!msg)
+ return -ENOMEM;
+
+ msg->slot = BIT(SCPI_SLOT);
+ msg->cmd = PACK_SCPI_CMD(cmd, tx_len);
+ msg->tx_buf = tx_buf;
+ msg->tx_len = tx_len;
+ msg->rx_buf = rx_buf;
+ msg->rx_len = rx_len;
+ init_completion(&msg->done);
+
+ ret = mbox_send_message(scpi_chan->chan, msg);
+ if (ret < 0 || !rx_buf)
+ goto out;
+
+ if (!wait_for_completion_timeout(&msg->done, MAX_RX_TIMEOUT))
+ ret = -ETIMEDOUT;
+ else
+ /* first status word */
+ ret = le32_to_cpu(msg->status);
+out:
+ if (ret < 0 && rx_buf) /* remove entry from the list if timed-out */
+ scpi_process_cmd(scpi_chan, msg->cmd);
+
+ put_scpi_xfer(msg, scpi_chan);
+ /* SCPI error codes > 0, translate them to Linux scale*/
+ return ret > 0 ? scpi_to_linux_errno(ret) : ret;
+}
+
+static u32 scpi_get_version(void)
+{
+ return scpi_info->protocol_version;
+}
+
+static int
+scpi_clk_get_range(u16 clk_id, unsigned long *min, unsigned long *max)
+{
+ int ret;
+ struct clk_get_info clk;
+ __le16 le_clk_id = cpu_to_le16(clk_id);
+
+ ret = scpi_send_message(SCPI_CMD_GET_CLOCK_INFO, &le_clk_id,
+ sizeof(le_clk_id), &clk, sizeof(clk));
+ if (!ret) {
+ *min = le32_to_cpu(clk.min_rate);
+ *max = le32_to_cpu(clk.max_rate);
+ }
+ return ret;
+}
+
+static unsigned long scpi_clk_get_val(u16 clk_id)
+{
+ int ret;
+ struct clk_get_value clk;
+ __le16 le_clk_id = cpu_to_le16(clk_id);
+
+ ret = scpi_send_message(SCPI_CMD_GET_CLOCK_VALUE, &le_clk_id,
+ sizeof(le_clk_id), &clk, sizeof(clk));
+ return ret ? ret : le32_to_cpu(clk.rate);
+}
+
+static int scpi_clk_set_val(u16 clk_id, unsigned long rate)
+{
+ int stat;
+ struct clk_set_value clk = {
+ .id = cpu_to_le16(clk_id),
+ .rate = cpu_to_le32(rate)
+ };
+
+ return scpi_send_message(SCPI_CMD_SET_CLOCK_VALUE, &clk, sizeof(clk),
+ &stat, sizeof(stat));
+}
+
+static int scpi_dvfs_get_idx(u8 domain)
+{
+ int ret;
+ struct dvfs_get dvfs;
+
+ ret = scpi_send_message(SCPI_CMD_GET_DVFS, &domain, sizeof(domain),
+ &dvfs, sizeof(dvfs));
+ return ret ? ret : dvfs.index;
+}
+
+static int scpi_dvfs_set_idx(u8 domain, u8 index)
+{
+ int stat;
+ struct dvfs_set dvfs = {domain, index};
+
+ return scpi_send_message(SCPI_CMD_SET_DVFS, &dvfs, sizeof(dvfs),
+ &stat, sizeof(stat));
+}
+
+static int opp_cmp_func(const void *opp1, const void *opp2)
+{
+ const struct scpi_opp *t1 = opp1, *t2 = opp2;
+
+ return t1->freq - t2->freq;
+}
+
+static struct scpi_dvfs_info *scpi_dvfs_get_info(u8 domain)
+{
+ struct scpi_dvfs_info *info;
+ struct scpi_opp *opp;
+ struct dvfs_info buf;
+ int ret, i;
+
+ if (domain >= MAX_DVFS_DOMAINS)
+ return ERR_PTR(-EINVAL);
+
+ if (scpi_info->dvfs[domain]) /* data already populated */
+ return scpi_info->dvfs[domain];
+
+ ret = scpi_send_message(SCPI_CMD_GET_DVFS_INFO, &domain, sizeof(domain),
+ &buf, sizeof(buf));
+
+ if (ret)
+ return ERR_PTR(ret);
+
+ info = kmalloc(sizeof(*info), GFP_KERNEL);
+ if (!info)
+ return ERR_PTR(-ENOMEM);
+
+ info->count = DVFS_OPP_COUNT(buf.header);
+ info->latency = DVFS_LATENCY(buf.header) * 1000; /* uS to nS */
+
+ info->opps = kcalloc(info->count, sizeof(*opp), GFP_KERNEL);
+ if (!info->opps) {
+ kfree(info);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ for (i = 0, opp = info->opps; i < info->count; i++, opp++) {
+ opp->freq = le32_to_cpu(buf.opps[i].freq);
+ opp->m_volt = le32_to_cpu(buf.opps[i].m_volt);
+ }
+
+ sort(info->opps, info->count, sizeof(*opp), opp_cmp_func, NULL);
+
+ scpi_info->dvfs[domain] = info;
+ return info;
+}
+
+static int scpi_sensor_get_capability(u16 *sensors)
+{
+ struct sensor_capabilities cap_buf;
+ int ret;
+
+ ret = scpi_send_message(SCPI_CMD_SENSOR_CAPABILITIES, NULL, 0, &cap_buf,
+ sizeof(cap_buf));
+ if (!ret)
+ *sensors = le16_to_cpu(cap_buf.sensors);
+
+ return ret;
+}
+
+static int scpi_sensor_get_info(u16 sensor_id, struct scpi_sensor_info *info)
+{
+ __le16 id = cpu_to_le16(sensor_id);
+ struct _scpi_sensor_info _info;
+ int ret;
+
+ ret = scpi_send_message(SCPI_CMD_SENSOR_INFO, &id, sizeof(id),
+ &_info, sizeof(_info));
+ if (!ret) {
+ memcpy(info, &_info, sizeof(*info));
+ info->sensor_id = le16_to_cpu(_info.sensor_id);
+ }
+
+ return ret;
+}
+
+int scpi_sensor_get_value(u16 sensor, u32 *val)
+{
+ struct sensor_value buf;
+ int ret;
+
+ ret = scpi_send_message(SCPI_CMD_SENSOR_VALUE, &sensor, sizeof(sensor),
+ &buf, sizeof(buf));
+ if (!ret)
+ *val = le32_to_cpu(buf.val);
+
+ return ret;
+}
+
+static struct scpi_ops scpi_ops = {
+ .get_version = scpi_get_version,
+ .clk_get_range = scpi_clk_get_range,
+ .clk_get_val = scpi_clk_get_val,
+ .clk_set_val = scpi_clk_set_val,
+ .dvfs_get_idx = scpi_dvfs_get_idx,
+ .dvfs_set_idx = scpi_dvfs_set_idx,
+ .dvfs_get_info = scpi_dvfs_get_info,
+ .sensor_get_capability = scpi_sensor_get_capability,
+ .sensor_get_info = scpi_sensor_get_info,
+ .sensor_get_value = scpi_sensor_get_value,
+};
+
+struct scpi_ops *get_scpi_ops(void)
+{
+ return scpi_info ? scpi_info->scpi_ops : NULL;
+}
+EXPORT_SYMBOL_GPL(get_scpi_ops);
+
+static int scpi_init_versions(struct scpi_drvinfo *info)
+{
+ int ret;
+ struct scp_capabilities caps;
+
+ ret = scpi_send_message(SCPI_CMD_SCPI_CAPABILITIES, NULL, 0,
+ &caps, sizeof(caps));
+ if (!ret) {
+ info->protocol_version = le32_to_cpu(caps.protocol_version);
+ info->firmware_version = le32_to_cpu(caps.platform_version);
+ }
+ return ret;
+}
+
+static ssize_t protocol_version_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct scpi_drvinfo *scpi_info = dev_get_drvdata(dev);
+
+ return sprintf(buf, "%d.%d\n",
+ PROTOCOL_REV_MAJOR(scpi_info->protocol_version),
+ PROTOCOL_REV_MINOR(scpi_info->protocol_version));
+}
+static DEVICE_ATTR_RO(protocol_version);
+
+static ssize_t firmware_version_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct scpi_drvinfo *scpi_info = dev_get_drvdata(dev);
+
+ return sprintf(buf, "%d.%d.%d\n",
+ FW_REV_MAJOR(scpi_info->firmware_version),
+ FW_REV_MINOR(scpi_info->firmware_version),
+ FW_REV_PATCH(scpi_info->firmware_version));
+}
+static DEVICE_ATTR_RO(firmware_version);
+
+static struct attribute *versions_attrs[] = {
+ &dev_attr_firmware_version.attr,
+ &dev_attr_protocol_version.attr,
+ NULL,
+};
+ATTRIBUTE_GROUPS(versions);
+
+static void
+scpi_free_channels(struct device *dev, struct scpi_chan *pchan, int count)
+{
+ int i;
+
+ for (i = 0; i < count && pchan->chan; i++, pchan++) {
+ mbox_free_channel(pchan->chan);
+ devm_kfree(dev, pchan->xfers);
+ devm_iounmap(dev, pchan->rx_payload);
+ }
+}
+
+static int scpi_remove(struct platform_device *pdev)
+{
+ int i;
+ struct device *dev = &pdev->dev;
+ struct scpi_drvinfo *info = platform_get_drvdata(pdev);
+
+ scpi_info = NULL; /* stop exporting SCPI ops through get_scpi_ops */
+
+ of_platform_depopulate(dev);
+ sysfs_remove_groups(&dev->kobj, versions_groups);
+ scpi_free_channels(dev, info->channels, info->num_chans);
+ platform_set_drvdata(pdev, NULL);
+
+ for (i = 0; i < MAX_DVFS_DOMAINS && info->dvfs[i]; i++) {
+ kfree(info->dvfs[i]->opps);
+ kfree(info->dvfs[i]);
+ }
+ devm_kfree(dev, info->channels);
+ devm_kfree(dev, info);
+
+ return 0;
+}
+
+#define MAX_SCPI_XFERS 10
+static int scpi_alloc_xfer_list(struct device *dev, struct scpi_chan *ch)
+{
+ int i;
+ struct scpi_xfer *xfers;
+
+ xfers = devm_kzalloc(dev, MAX_SCPI_XFERS * sizeof(*xfers), GFP_KERNEL);
+ if (!xfers)
+ return -ENOMEM;
+
+ ch->xfers = xfers;
+ for (i = 0; i < MAX_SCPI_XFERS; i++, xfers++)
+ list_add_tail(&xfers->node, &ch->xfers_list);
+ return 0;
+}
+
+static int scpi_probe(struct platform_device *pdev)
+{
+ int count, idx, ret;
+ struct resource res;
+ struct scpi_chan *scpi_chan;
+ struct device *dev = &pdev->dev;
+ struct device_node *np = dev->of_node;
+
+ scpi_info = devm_kzalloc(dev, sizeof(*scpi_info), GFP_KERNEL);
+ if (!scpi_info)
+ return -ENOMEM;
+
+ count = of_count_phandle_with_args(np, "mboxes", "#mbox-cells");
+ if (count < 0) {
+ dev_err(dev, "no mboxes property in '%s'\n", np->full_name);
+ return -ENODEV;
+ }
+
+ scpi_chan = devm_kcalloc(dev, count, sizeof(*scpi_chan), GFP_KERNEL);
+ if (!scpi_chan)
+ return -ENOMEM;
+
+ for (idx = 0; idx < count; idx++) {
+ resource_size_t size;
+ struct scpi_chan *pchan = scpi_chan + idx;
+ struct mbox_client *cl = &pchan->cl;
+ struct device_node *shmem = of_parse_phandle(np, "shmem", idx);
+
+ if (of_address_to_resource(shmem, 0, &res)) {
+ dev_err(dev, "failed to get SCPI payload mem resource\n");
+ ret = -EINVAL;
+ goto err;
+ }
+
+ size = resource_size(&res);
+ pchan->rx_payload = devm_ioremap(dev, res.start, size);
+ if (!pchan->rx_payload) {
+ dev_err(dev, "failed to ioremap SCPI payload\n");
+ ret = -EADDRNOTAVAIL;
+ goto err;
+ }
+ pchan->tx_payload = pchan->rx_payload + (size >> 1);
+
+ cl->dev = dev;
+ cl->rx_callback = scpi_handle_remote_msg;
+ cl->tx_prepare = scpi_tx_prepare;
+ cl->tx_block = true;
+ cl->tx_tout = 50;
+ cl->knows_txdone = false; /* controller can't ack */
+
+ INIT_LIST_HEAD(&pchan->rx_pending);
+ INIT_LIST_HEAD(&pchan->xfers_list);
+ spin_lock_init(&pchan->rx_lock);
+ mutex_init(&pchan->xfers_lock);
+
+ ret = scpi_alloc_xfer_list(dev, pchan);
+ if (!ret) {
+ pchan->chan = mbox_request_channel(cl, idx);
+ if (!IS_ERR(pchan->chan))
+ continue;
+ ret = PTR_ERR(pchan->chan);
+ if (ret != -EPROBE_DEFER)
+ dev_err(dev, "failed to get channel%d err %d\n",
+ idx, ret);
+ }
+err:
+ scpi_free_channels(dev, scpi_chan, idx);
+ scpi_info = NULL;
+ return ret;
+ }
+
+ scpi_info->channels = scpi_chan;
+ scpi_info->num_chans = count;
+ platform_set_drvdata(pdev, scpi_info);
+
+ ret = scpi_init_versions(scpi_info);
+ if (ret) {
+ dev_err(dev, "incorrect or no SCP firmware found\n");
+ scpi_remove(pdev);
+ return ret;
+ }
+
+ _dev_info(dev, "SCP Protocol %d.%d Firmware %d.%d.%d version\n",
+ PROTOCOL_REV_MAJOR(scpi_info->protocol_version),
+ PROTOCOL_REV_MINOR(scpi_info->protocol_version),
+ FW_REV_MAJOR(scpi_info->firmware_version),
+ FW_REV_MINOR(scpi_info->firmware_version),
+ FW_REV_PATCH(scpi_info->firmware_version));
+ scpi_info->scpi_ops = &scpi_ops;
+
+ ret = sysfs_create_groups(&dev->kobj, versions_groups);
+ if (ret)
+ dev_err(dev, "unable to create sysfs version group\n");
+
+ return of_platform_populate(dev->of_node, NULL, NULL, dev);
+}
+
+static const struct of_device_id scpi_of_match[] = {
+ {.compatible = "arm,scpi"},
+ {},
+};
+
+MODULE_DEVICE_TABLE(of, scpi_of_match);
+
+static struct platform_driver scpi_driver = {
+ .driver = {
+ .name = "scpi_protocol",
+ .of_match_table = scpi_of_match,
+ },
+ .probe = scpi_probe,
+ .remove = scpi_remove,
+};
+module_platform_driver(scpi_driver);
+
+MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
+MODULE_DESCRIPTION("ARM SCPI mailbox protocol driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index e13c902e8966..50146bb69833 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -321,6 +321,14 @@ config SENSORS_APPLESMC
Say Y here if you have an applicable laptop and want to experience
the awesome power of applesmc.
+config SENSORS_ARM_SCPI
+ tristate "ARM SCPI Sensors"
+ depends on ARM_SCPI_PROTOCOL
+ help
+ This driver provides support for temperature, voltage, current
+ and power sensors available on ARM Ltd's SCP based platforms. The
+ actual number and type of sensors exported depend on the platform.
+
config SENSORS_ASB100
tristate "Asus ASB100 Bach"
depends on X86 && I2C
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 9e0f3dd2841d..66e7a4715da7 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -44,6 +44,7 @@ obj-$(CONFIG_SENSORS_ADT7462) += adt7462.o
obj-$(CONFIG_SENSORS_ADT7470) += adt7470.o
obj-$(CONFIG_SENSORS_ADT7475) += adt7475.o
obj-$(CONFIG_SENSORS_APPLESMC) += applesmc.o
+obj-$(CONFIG_SENSORS_ARM_SCPI) += scpi-hwmon.o
obj-$(CONFIG_SENSORS_ASC7621) += asc7621.o
obj-$(CONFIG_SENSORS_ATXP1) += atxp1.o
obj-$(CONFIG_SENSORS_CORETEMP) += coretemp.o
diff --git a/drivers/hwmon/scpi-hwmon.c b/drivers/hwmon/scpi-hwmon.c
new file mode 100644
index 000000000000..2c1241bbf9af
--- /dev/null
+++ b/drivers/hwmon/scpi-hwmon.c
@@ -0,0 +1,288 @@
+/*
+ * System Control and Power Interface(SCPI) based hwmon sensor driver
+ *
+ * Copyright (C) 2015 ARM Ltd.
+ * Punit Agrawal <punit.agrawal@arm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/hwmon.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/scpi_protocol.h>
+#include <linux/slab.h>
+#include <linux/sysfs.h>
+#include <linux/thermal.h>
+
+struct sensor_data {
+ struct scpi_sensor_info info;
+ struct device_attribute dev_attr_input;
+ struct device_attribute dev_attr_label;
+ char input[20];
+ char label[20];
+};
+
+struct scpi_thermal_zone {
+ struct list_head list;
+ int sensor_id;
+ struct scpi_sensors *scpi_sensors;
+ struct thermal_zone_device *tzd;
+};
+
+struct scpi_sensors {
+ struct scpi_ops *scpi_ops;
+ struct sensor_data *data;
+ struct list_head thermal_zones;
+ struct attribute **attrs;
+ struct attribute_group group;
+ const struct attribute_group *groups[2];
+};
+
+static int scpi_read_temp(void *dev, int *temp)
+{
+ struct scpi_thermal_zone *zone = dev;
+ struct scpi_sensors *scpi_sensors = zone->scpi_sensors;
+ struct scpi_ops *scpi_ops = scpi_sensors->scpi_ops;
+ struct sensor_data *sensor = &scpi_sensors->data[zone->sensor_id];
+ u32 value;
+ int ret;
+
+ ret = scpi_ops->sensor_get_value(sensor->info.sensor_id, &value);
+ if (ret)
+ return ret;
+
+ *temp = value;
+ return 0;
+}
+
+/* hwmon callback functions */
+static ssize_t
+scpi_show_sensor(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ struct scpi_sensors *scpi_sensors = dev_get_drvdata(dev);
+ struct scpi_ops *scpi_ops = scpi_sensors->scpi_ops;
+ struct sensor_data *sensor;
+ u32 value;
+ int ret;
+
+ sensor = container_of(attr, struct sensor_data, dev_attr_input);
+
+ ret = scpi_ops->sensor_get_value(sensor->info.sensor_id, &value);
+ if (ret)
+ return ret;
+
+ return sprintf(buf, "%u\n", value);
+}
+
+static ssize_t
+scpi_show_label(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ struct sensor_data *sensor;
+
+ sensor = container_of(attr, struct sensor_data, dev_attr_label);
+
+ return sprintf(buf, "%s\n", sensor->info.name);
+}
+
+static void
+unregister_thermal_zones(struct platform_device *pdev,
+ struct scpi_sensors *scpi_sensors)
+{
+ struct list_head *pos;
+
+ list_for_each(pos, &scpi_sensors->thermal_zones) {
+ struct scpi_thermal_zone *zone;
+
+ zone = list_entry(pos, struct scpi_thermal_zone, list);
+ thermal_zone_of_sensor_unregister(&pdev->dev, zone->tzd);
+ }
+}
+
+static struct thermal_zone_of_device_ops scpi_sensor_ops = {
+ .get_temp = scpi_read_temp,
+};
+
+static int scpi_hwmon_probe(struct platform_device *pdev)
+{
+ u16 nr_sensors, i;
+ int num_temp = 0, num_volt = 0, num_current = 0, num_power = 0;
+ struct scpi_ops *scpi_ops;
+ struct device *hwdev, *dev = &pdev->dev;
+ struct scpi_sensors *scpi_sensors;
+ int ret;
+
+ scpi_ops = get_scpi_ops();
+ if (!scpi_ops)
+ return -EPROBE_DEFER;
+
+ ret = scpi_ops->sensor_get_capability(&nr_sensors);
+ if (ret)
+ return ret;
+
+ if (!nr_sensors)
+ return -ENODEV;
+
+ scpi_sensors = devm_kzalloc(dev, sizeof(*scpi_sensors), GFP_KERNEL);
+ if (!scpi_sensors)
+ return -ENOMEM;
+
+ scpi_sensors->data = devm_kcalloc(dev, nr_sensors,
+ sizeof(*scpi_sensors->data), GFP_KERNEL);
+ if (!scpi_sensors->data)
+ return -ENOMEM;
+
+ scpi_sensors->attrs = devm_kcalloc(dev, (nr_sensors * 2) + 1,
+ sizeof(*scpi_sensors->attrs), GFP_KERNEL);
+ if (!scpi_sensors->attrs)
+ return -ENOMEM;
+
+ scpi_sensors->scpi_ops = scpi_ops;
+
+ for (i = 0; i < nr_sensors; i++) {
+ struct sensor_data *sensor = &scpi_sensors->data[i];
+
+ ret = scpi_ops->sensor_get_info(i, &sensor->info);
+ if (ret)
+ return ret;
+
+ switch (sensor->info.class) {
+ case TEMPERATURE:
+ snprintf(sensor->input, sizeof(sensor->input),
+ "temp%d_input", num_temp + 1);
+ snprintf(sensor->label, sizeof(sensor->input),
+ "temp%d_label", num_temp + 1);
+ num_temp++;
+ break;
+ case VOLTAGE:
+ snprintf(sensor->input, sizeof(sensor->input),
+ "in%d_input", num_volt);
+ snprintf(sensor->label, sizeof(sensor->input),
+ "in%d_label", num_volt);
+ num_volt++;
+ break;
+ case CURRENT:
+ snprintf(sensor->input, sizeof(sensor->input),
+ "curr%d_input", num_current + 1);
+ snprintf(sensor->label, sizeof(sensor->input),
+ "curr%d_label", num_current + 1);
+ num_current++;
+ break;
+ case POWER:
+ snprintf(sensor->input, sizeof(sensor->input),
+ "power%d_input", num_power + 1);
+ snprintf(sensor->label, sizeof(sensor->input),
+ "power%d_label", num_power + 1);
+ num_power++;
+ break;
+ default:
+ break;
+ }
+
+ sensor->dev_attr_input.attr.mode = S_IRUGO;
+ sensor->dev_attr_input.show = scpi_show_sensor;
+ sensor->dev_attr_input.attr.name = sensor->input;
+
+ sensor->dev_attr_label.attr.mode = S_IRUGO;
+ sensor->dev_attr_label.show = scpi_show_label;
+ sensor->dev_attr_label.attr.name = sensor->label;
+
+ scpi_sensors->attrs[i << 1] = &sensor->dev_attr_input.attr;
+ scpi_sensors->attrs[(i << 1) + 1] = &sensor->dev_attr_label.attr;
+
+ sysfs_attr_init(scpi_sensors->attrs[i << 1]);
+ sysfs_attr_init(scpi_sensors->attrs[(i << 1) + 1]);
+ }
+
+ scpi_sensors->group.attrs = scpi_sensors->attrs;
+ scpi_sensors->groups[0] = &scpi_sensors->group;
+
+ platform_set_drvdata(pdev, scpi_sensors);
+
+ hwdev = devm_hwmon_device_register_with_groups(dev,
+ "scpi_sensors", scpi_sensors, scpi_sensors->groups);
+
+ if (IS_ERR(hwdev))
+ return PTR_ERR(hwdev);
+
+ /*
+ * Register the temperature sensors with the thermal framework
+ * to allow their usage in setting up the thermal zones from
+ * device tree.
+ *
+ * NOTE: Not all temperature sensors maybe used for thermal
+ * control
+ */
+ INIT_LIST_HEAD(&scpi_sensors->thermal_zones);
+ for (i = 0; i < nr_sensors; i++) {
+ struct sensor_data *sensor = &scpi_sensors->data[i];
+ struct scpi_thermal_zone *zone;
+
+ if (sensor->info.class != TEMPERATURE)
+ continue;
+
+ zone = devm_kzalloc(dev, sizeof(*zone), GFP_KERNEL);
+ if (!zone) {
+ ret = -ENOMEM;
+ goto unregister_tzd;
+ }
+
+ zone->sensor_id = i;
+ zone->scpi_sensors = scpi_sensors;
+ zone->tzd = thermal_zone_of_sensor_register(dev, i, zone,
+ &scpi_sensor_ops);
+ /*
+ * The call to thermal_zone_of_sensor_register returns
+ * an error for sensors that are not associated with
+ * any thermal zones or if the thermal subsystem is
+ * not configured.
+ */
+ if (IS_ERR(zone->tzd)) {
+ devm_kfree(dev, zone);
+ continue;
+ }
+ list_add(&zone->list, &scpi_sensors->thermal_zones);
+ }
+
+ return 0;
+
+unregister_tzd:
+ unregister_thermal_zones(pdev, scpi_sensors);
+ return ret;
+}
+
+static int scpi_hwmon_remove(struct platform_device *pdev)
+{
+ struct scpi_sensors *scpi_sensors = platform_get_drvdata(pdev);
+
+ unregister_thermal_zones(pdev, scpi_sensors);
+
+ return 0;
+}
+
+static const struct of_device_id scpi_of_match[] = {
+ {.compatible = "arm,scpi-sensors"},
+ {},
+};
+
+static struct platform_driver scpi_hwmon_platdrv = {
+ .driver = {
+ .name = "scpi-hwmon",
+ .owner = THIS_MODULE,
+ .of_match_table = scpi_of_match,
+ },
+ .probe = scpi_hwmon_probe,
+ .remove = scpi_hwmon_remove,
+};
+module_platform_driver(scpi_hwmon_platdrv);
+
+MODULE_AUTHOR("Punit Agrawal <punit.agrawal@arm.com>");
+MODULE_DESCRIPTION("ARM SCPI HWMON interface driver");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/scpi_protocol.h b/include/linux/scpi_protocol.h
new file mode 100644
index 000000000000..80af3cd35ae4
--- /dev/null
+++ b/include/linux/scpi_protocol.h
@@ -0,0 +1,78 @@
+/*
+ * SCPI Message Protocol driver header
+ *
+ * Copyright (C) 2014 ARM Ltd.
+ *
+ * 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/types.h>
+
+struct scpi_opp {
+ u32 freq;
+ u32 m_volt;
+} __packed;
+
+struct scpi_dvfs_info {
+ unsigned int count;
+ unsigned int latency; /* in nanoseconds */
+ struct scpi_opp *opps;
+};
+
+enum scpi_sensor_class {
+ TEMPERATURE,
+ VOLTAGE,
+ CURRENT,
+ POWER,
+};
+
+struct scpi_sensor_info {
+ u16 sensor_id;
+ u8 class;
+ u8 trigger_type;
+ char name[20];
+} __packed;
+
+/**
+ * struct scpi_ops - represents the various operations provided
+ * by SCP through SCPI message protocol
+ * @get_version: returns the major and minor revision on the SCPI
+ * message protocol
+ * @clk_get_range: gets clock range limit(min - max in Hz)
+ * @clk_get_val: gets clock value(in Hz)
+ * @clk_set_val: sets the clock value, setting to 0 will disable the
+ * clock (if supported)
+ * @dvfs_get_idx: gets the Operating Point of the given power domain.
+ * OPP is an index to the list return by @dvfs_get_info
+ * @dvfs_set_idx: sets the Operating Point of the given power domain.
+ * OPP is an index to the list return by @dvfs_get_info
+ * @dvfs_get_info: returns the DVFS capabilities of the given power
+ * domain. It includes the OPP list and the latency information
+ */
+struct scpi_ops {
+ u32 (*get_version)(void);
+ int (*clk_get_range)(u16, unsigned long *, unsigned long *);
+ unsigned long (*clk_get_val)(u16);
+ int (*clk_set_val)(u16, unsigned long);
+ int (*dvfs_get_idx)(u8);
+ int (*dvfs_set_idx)(u8, u8);
+ struct scpi_dvfs_info *(*dvfs_get_info)(u8);
+ int (*sensor_get_capability)(u16 *sensors);
+ int (*sensor_get_info)(u16 sensor_id, struct scpi_sensor_info *);
+ int (*sensor_get_value)(u16, u32 *);
+};
+
+#if IS_ENABLED(CONFIG_ARM_SCPI_PROTOCOL)
+struct scpi_ops *get_scpi_ops(void);
+#else
+static inline struct scpi_ops *get_scpi_ops(void) { return NULL; }
+#endif