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[PATCH REPOST v6 0/8] ARM64: juno: add SCPI mailbox protocol, clock and CPUFreq support

Started bySudeep Holla <sudeep.holla@arm.com>
First post2015-09-16 19:20 +0200
Last post2015-09-16 19:20 +0200
Articles 4 — 1 participant

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Contents

  [PATCH REPOST v6 0/8] ARM64: juno: add SCPI mailbox protocol, clock and CPUFreq support Sudeep Holla <sudeep.holla@arm.com> - 2015-09-16 19:20 +0200
    [PATCH REPOST v6 5/8] cpufreq: arm_big_little: add SCPI interface driver Sudeep Holla <sudeep.holla@arm.com> - 2015-09-16 19:20 +0200
    [PATCH REPOST v6 6/8] arm64: dts: add SRAM, MHU mailbox and SCPI support on Juno Sudeep Holla <sudeep.holla@arm.com> - 2015-09-16 19:20 +0200
    [PATCH REPOST v6 3/8] clk: add support for clocks provided by SCP(System Control Processor) Sudeep Holla <sudeep.holla@arm.com> - 2015-09-16 19:20 +0200

#1226303 — [PATCH REPOST v6 0/8] ARM64: juno: add SCPI mailbox protocol, clock and CPUFreq support

FromSudeep Holla <sudeep.holla@arm.com>
Date2015-09-16 19:20 +0200
Subject[PATCH REPOST v6 0/8] ARM64: juno: add SCPI mailbox protocol, clock and CPUFreq support
Message-ID<q9oxb-2sA-3@gated-at.bofh.it>
Hi ARM-SoC guys,

Olof had confused this with PSCI[0]. I assume the confusion is now
resolved ? I have now rebased the series on top of v4.3-rc1 and just
resending them again.

Please pull this series for v4.4

You can access it from:
	git://linux-arm.org/linux-skn.git juno_dvfs

BUT the ARM external git repository is still unreliable and hence I am
avoiding pull request. Can I request to pull it from the mails directly
instead ? Extremely sorry for the inconvenience.

Regards,
Sudeep

This patch series adds support for:
  1. SCPI(System Control and Power Interface) mailbox protocol driver.
     It uses ARM MHU mailbox controller driver on Juno but can work with
     any mailbox controllers using standard mailbox APIs
  2. Add support for clocks provided by SCP firmware through the SCPI
     interface
  3. Using the existing arm_big_little cpufreq driver and the newly
     added SCPI clock driver, it also adds support for CPU DVFS on
     ARM64 JUNO development platforms.

The SCPI protocol document is available @[1]

[0] http://lists.infradead.org/pipermail/linux-arm-kernel/2015-August/364229.html
[1] http://infocenter.arm.com/help/topic/com.arm.doc.dui0922b/index.html
v1: https://lkml.org/lkml/2015/4/27/232
v2: https://lkml.org/lkml/2015/5/14/470
v3: https://lkml.org/lkml/2015/5/27/220
v4: https://lkml.org/lkml/2015/6/8/178
v5: https://lkml.org/lkml/2015/7/23/270
v6: https://lkml.org/lkml/2015/7/31/692

Cc: devicetree@vger.kernel.org
Cc: linux-clk@vger.kernel.org
Cc: linux-pm@vger.kernel.org

Sudeep Holla (8):
  Documentation: add DT binding for ARM System Control and Power
    Interface(SCPI) protocol
  firmware: add support for ARM System Control and Power Interface(SCPI)
    protocol
  clk: add support for clocks provided by SCP(System Control Processor)
  clk: scpi: add support for cpufreq virtual device
  cpufreq: arm_big_little: add SCPI interface driver
  arm64: dts: add SRAM, MHU mailbox and SCPI support on Juno
  arm64: dts: add CPU topology on Juno
  arm64: dts: add clock support for all the cpus

 Documentation/devicetree/bindings/arm/arm,scpi.txt | 150 +++++
 MAINTAINERS                                        |  10 +
 arch/arm64/boot/dts/arm/juno-base.dtsi             |  54 ++
 arch/arm64/boot/dts/arm/juno-r1.dts                |  32 +
 arch/arm64/boot/dts/arm/juno.dts                   |  32 +
 drivers/clk/Kconfig                                |  10 +
 drivers/clk/Makefile                               |   1 +
 drivers/clk/clk-scpi.c                             | 325 ++++++++++
 drivers/cpufreq/Kconfig.arm                        |  10 +
 drivers/cpufreq/Makefile                           |   1 +
 drivers/cpufreq/scpi-cpufreq.c                     | 124 ++++
 drivers/firmware/Kconfig                           |  19 +
 drivers/firmware/Makefile                          |   1 +
 drivers/firmware/arm_scpi.c                        | 711 +++++++++++++++++++++
 include/linux/scpi_protocol.h                      |  61 ++
 15 files changed, 1541 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/arm/arm,scpi.txt
 create mode 100644 drivers/clk/clk-scpi.c
 create mode 100644 drivers/cpufreq/scpi-cpufreq.c
 create mode 100644 drivers/firmware/arm_scpi.c
 create mode 100644 include/linux/scpi_protocol.h

-- 
1.9.1

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#1226304 — [PATCH REPOST v6 5/8] cpufreq: arm_big_little: add SCPI interface driver

FromSudeep Holla <sudeep.holla@arm.com>
Date2015-09-16 19:20 +0200
Subject[PATCH REPOST v6 5/8] cpufreq: arm_big_little: add SCPI interface driver
Message-ID<q9oxd-2sA-23@gated-at.bofh.it>
In reply to#1226303
On some ARM based systems, a separate Cortex-M based System Control
Processor(SCP) provides the overall power, clock, reset and system
control including CPU DVFS. SCPI Message Protocol is used to
communicate with the SCPI.

This patch adds a interface driver for adding OPPs and registering
the arm_big_little cpufreq driver for such systems.

Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: linux-pm@vger.kernel.org
---
 MAINTAINERS                    |   1 +
 drivers/cpufreq/Kconfig.arm    |  10 ++++
 drivers/cpufreq/Makefile       |   1 +
 drivers/cpufreq/scpi-cpufreq.c | 124 +++++++++++++++++++++++++++++++++++++++++
 4 files changed, 136 insertions(+)
 create mode 100644 drivers/cpufreq/scpi-cpufreq.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 613a116ab0f4..e39ae88cf423 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -9155,6 +9155,7 @@ 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
 
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");
-- 
1.9.1

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#1226306 — [PATCH REPOST v6 6/8] arm64: dts: add SRAM, MHU mailbox and SCPI support on Juno

FromSudeep Holla <sudeep.holla@arm.com>
Date2015-09-16 19:20 +0200
Subject[PATCH REPOST v6 6/8] arm64: dts: add SRAM, MHU mailbox and SCPI support on Juno
Message-ID<q9oxd-2sA-27@gated-at.bofh.it>
In reply to#1226303
This patch adds support for the MHU mailbox peripheral used on Juno by
application processors to communicate with remote SCP handling most of
the CPU/system power management. It also adds the SRAM reserving the
shared memory and SCPI message protocol using that shared memory.

Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Liviu Dudau <Liviu.Dudau@arm.com>
Cc: Jon Medhurst (Tixy) <tixy@linaro.org>
---
 arch/arm64/boot/dts/arm/juno-base.dtsi | 54 ++++++++++++++++++++++++++++++++++
 1 file changed, 54 insertions(+)

diff --git a/arch/arm64/boot/dts/arm/juno-base.dtsi b/arch/arm64/boot/dts/arm/juno-base.dtsi
index e3ee96036eca..c624208edef6 100644
--- a/arch/arm64/boot/dts/arm/juno-base.dtsi
+++ b/arch/arm64/boot/dts/arm/juno-base.dtsi
@@ -17,6 +17,18 @@
 		};
 	};
 
+	mailbox: mhu@2b1f0000 {
+		compatible = "arm,mhu", "arm,primecell";
+		reg = <0x0 0x2b1f0000 0x0 0x1000>;
+		interrupts = <GIC_SPI 36 IRQ_TYPE_LEVEL_HIGH>,
+			     <GIC_SPI 35 IRQ_TYPE_LEVEL_HIGH>;
+		interrupt-names = "mhu_lpri_rx",
+				  "mhu_hpri_rx";
+		#mbox-cells = <1>;
+		clocks = <&soc_refclk100mhz>;
+		clock-names = "apb_pclk";
+	};
+
 	gic: interrupt-controller@2c010000 {
 		compatible = "arm,gic-400", "arm,cortex-a15-gic";
 		reg = <0x0 0x2c010000 0 0x1000>,
@@ -44,6 +56,48 @@
 			     <GIC_PPI 10 (GIC_CPU_MASK_SIMPLE(6) | IRQ_TYPE_LEVEL_LOW)>;
 	};
 
+	sram: sram@2e000000 {
+		compatible = "arm,juno-sram-ns", "mmio-sram";
+		reg = <0x0 0x2e000000 0x0 0x8000>;
+
+		#address-cells = <1>;
+		#size-cells = <1>;
+		ranges = <0 0x0 0x2e000000 0x8000>;
+
+		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>;
+		};
+	};
+
+	scpi {
+		compatible = "arm,scpi";
+		mboxes = <&mailbox 1>;
+		shmem = <&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";
+			};
+		};
+	};
+
 	/include/ "juno-clocks.dtsi"
 
 	dma@7ff00000 {
-- 
1.9.1

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#1226307 — [PATCH REPOST v6 3/8] clk: add support for clocks provided by SCP(System Control Processor)

FromSudeep Holla <sudeep.holla@arm.com>
Date2015-09-16 19:20 +0200
Subject[PATCH REPOST v6 3/8] clk: add support for clocks provided by SCP(System Control Processor)
Message-ID<q9oxd-2sA-21@gated-at.bofh.it>
In reply to#1226303
On some ARM based systems, a separate Cortex-M based System Control
Processor(SCP) provides the overall power, clock, reset and system
control. System Control and Power Interface(SCPI) Message Protocol
is defined for the communication between the Application Cores(AP)
and the SCP.

This patch adds support for the clocks provided by SCP using SCPI
protocol.

Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: Mike Turquette <mturquette@baylibre.com>
Cc: Liviu Dudau <Liviu.Dudau@arm.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Jon Medhurst (Tixy) <tixy@linaro.org>
Cc: linux-clk@vger.kernel.org
---
 MAINTAINERS            |   1 +
 drivers/clk/Kconfig    |  10 ++
 drivers/clk/Makefile   |   1 +
 drivers/clk/clk-scpi.c | 312 +++++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 324 insertions(+)
 create mode 100644 drivers/clk/clk-scpi.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 9598821d6a37..613a116ab0f4 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -9154,6 +9154,7 @@ 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/firmware/arm_scpi.c
 F:	include/linux/scpi_protocol.h
 
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..e8323db300e2
--- /dev/null
+++ b/drivers/clk/clk-scpi.c
@@ -0,0 +1,312 @@
+/*
+ * 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 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;
+
+	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;
+		}
+	}
+	return 0;
+}
+
+static const struct of_device_id scpi_clocks_ids[] = {
+	{ .compatible = "arm,scpi-clocks", },
+	{}
+};
+MODULE_DEVICE_TABLE(of, scpi_clocks_id);
+
+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");
-- 
1.9.1

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