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ARM System Control and Power Interface(SCPI) support

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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
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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
This commit is contained in:
Arnd Bergmann 2015-10-14 17:07:32 +02:00
commit c049adc9fd
16 changed files with 1868 additions and 0 deletions
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188
Documentation/devicetree/bindings/arm/arm,scpi.txt Normal file
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@ -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.

33
Documentation/hwmon/scpi-hwmon Normal file
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@ -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.

10
MAINTAINERS
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@ -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

10
drivers/clk/Kconfig
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@ -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

1
drivers/clk/Makefile
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@ -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

325
drivers/clk/clk-scpi.c Normal file
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@ -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");

10
drivers/cpufreq/Kconfig.arm
View File

@ -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

1
drivers/cpufreq/Makefile
View File

@ -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

124
drivers/cpufreq/scpi-cpufreq.c Normal file
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@ -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");

19
drivers/firmware/Kconfig
View File

@ -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

1
drivers/firmware/Makefile
View File

@ -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

771
drivers/firmware/arm_scpi.c Normal file
View File

@ -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");

8
drivers/hwmon/Kconfig
View File

@ -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

1
drivers/hwmon/Makefile
View File

@ -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

288
drivers/hwmon/scpi-hwmon.c Normal file
View File

@ -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");

78
include/linux/scpi_protocol.h Normal file
View File

@ -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