Initial support for Raspberry Pi cpufreq driver

1 files changed, 273 insertions, 0 deletions

diff --git a/bcm2835-cpufreq-add-CPU-frequency-control-driver.patch b/bcm2835-cpufreq-add-CPU-frequency-control-driver.patch
new file mode 100644
index 000000000..b087998cb
--- /dev/null
+++ b/bcm2835-cpufreq-add-CPU-frequency-control-driver.patch
@@ -0,0 +1,273 @@
+From 624e057827435de39274c34e20c2d937cb9d4ac3 Mon Sep 17 00:00:00 2001
+From: Peter Robinson <pbrobinson@gmail.com>
+Date: Thu, 31 May 2018 19:08:12 +0100
+Subject: [PATCH] bcm2835: cpufreq: add CPU frequency control driver
+
+Signed-off-by: Peter Robinson <pbrobinson@gmail.com>
+---
+ arch/arm/boot/dts/bcm2835-rpi.dtsi |   7 ++
+ arch/arm/boot/dts/bcm2837.dtsi     |  33 +++++++
+ drivers/clk/bcm/Kconfig            |   8 ++
+ drivers/clk/bcm/Makefile           |   1 +
+ drivers/clk/bcm/clk-raspberrypi.c  | 138 +++++++++++++++++++++++++++++
+ 5 files changed, 187 insertions(+)
+ create mode 100644 drivers/clk/bcm/clk-raspberrypi.c
+
+diff --git a/arch/arm/boot/dts/bcm2835-rpi.dtsi b/arch/arm/boot/dts/bcm2835-rpi.dtsi
+index 6c3cfaa77f3d..e6d1627ec421 100644
+--- a/arch/arm/boot/dts/bcm2835-rpi.dtsi
++++ b/arch/arm/boot/dts/bcm2835-rpi.dtsi
+@@ -35,6 +35,13 @@
+ 			reg = <0x7e00b840 0xf>;
+ 			interrupts = <0 2>;
+ 		};
++
++		arm_clk: arm_clk {
++			compatible = "raspberrypi,bcm2835-cpu";
++			clocks = <&clocks BCM2835_CLOCK_VPU>;
++			#clock-cells = <0>;
++			clock-output-names = "arm";
++		};
+ 	};
+ };
+ 
+diff --git a/arch/arm/boot/dts/bcm2837.dtsi b/arch/arm/boot/dts/bcm2837.dtsi
+index 7704bb029605..c24176282a1f 100644
+--- a/arch/arm/boot/dts/bcm2837.dtsi
++++ b/arch/arm/boot/dts/bcm2837.dtsi
+@@ -38,6 +38,9 @@
+ 			reg = <0>;
+ 			enable-method = "spin-table";
+ 			cpu-release-addr = <0x0 0x000000d8>;
++			clocks = <&arm_clk>;
++			clock-names = "cpu";
++			operating-points-v2 = <&cpu0_opp_table>;
+ 		};
+ 
+ 		cpu1: cpu@1 {
+@@ -46,6 +49,9 @@
+ 			reg = <1>;
+ 			enable-method = "spin-table";
+ 			cpu-release-addr = <0x0 0x000000e0>;
++			clocks = <&arm_clk>;
++			clock-names = "cpu";
++			operating-points-v2 = <&cpu0_opp_table>;
+ 		};
+ 
+ 		cpu2: cpu@2 {
+@@ -54,6 +60,9 @@
+ 			reg = <2>;
+ 			enable-method = "spin-table";
+ 			cpu-release-addr = <0x0 0x000000e8>;
++			clocks = <&arm_clk>;
++			clock-names = "cpu";
++			operating-points-v2 = <&cpu0_opp_table>;
+ 		};
+ 
+ 		cpu3: cpu@3 {
+@@ -62,6 +71,30 @@
+ 			reg = <3>;
+ 			enable-method = "spin-table";
+ 			cpu-release-addr = <0x0 0x000000f0>;
++			clocks = <&arm_clk>;
++			clock-names = "cpu";
++			operating-points-v2 = <&cpu0_opp_table>;
++		};
++	};
++
++	cpu0_opp_table: opp_table0 {
++		compatible = "operating-points-v2";
++		opp-shared;
++
++		opp@600000000 {
++			opp-hz = /bits/ 64 <600000000>;
++			clock-latency-ns = <355000>;
++			opp-suspend;
++		};
++
++		opp@900000000 {
++			opp-hz = /bits/ 64 <900000000>;
++			clock-latency-ns = <355000>;
++		};
++
++		opp@1200000000 {
++			opp-hz = /bits/ 64 <1200000000>;
++			clock-latency-ns = <355000>;
+ 		};
+ 	};
+ };
+diff --git a/drivers/clk/bcm/Kconfig b/drivers/clk/bcm/Kconfig
+index 4c4bd85f707c..e40bd19da22b 100644
+--- a/drivers/clk/bcm/Kconfig
++++ b/drivers/clk/bcm/Kconfig
+@@ -63,3 +63,11 @@ config CLK_BCM_SR
+ 	default ARCH_BCM_IPROC
+ 	help
+ 	  Enable common clock framework support for the Broadcom Stingray SoC
++
++config CLK_RASPBERRYPI_CPU
++	bool "Raspberry Pi CPU clock driver"
++	depends on ARCH_BCM2835 || (COMPILE_TEST && OF)
++	depends on RASPBERRYPI_FIRMWARE=y
++	help
++	  This enables support for the RPi CPU clock which can be adjusted
++	  via the RPi firmware.
+diff --git a/drivers/clk/bcm/Makefile b/drivers/clk/bcm/Makefile
+index 002661d39128..a028b0a90b6e 100644
+--- a/drivers/clk/bcm/Makefile
++++ b/drivers/clk/bcm/Makefile
+@@ -8,6 +8,7 @@ obj-$(CONFIG_COMMON_CLK_IPROC)	+= clk-iproc-armpll.o clk-iproc-pll.o clk-iproc-a
+ obj-$(CONFIG_ARCH_BCM2835)	+= clk-bcm2835.o
+ obj-$(CONFIG_ARCH_BCM2835)	+= clk-bcm2835-aux.o
+ obj-$(CONFIG_ARCH_BCM_53573)	+= clk-bcm53573-ilp.o
++obj-$(CONFIG_CLK_RASPBERRYPI_CPU)	+= clk-raspberrypi.o
+ obj-$(CONFIG_CLK_BCM_CYGNUS)	+= clk-cygnus.o
+ obj-$(CONFIG_CLK_BCM_HR2)	+= clk-hr2.o
+ obj-$(CONFIG_CLK_BCM_NSP)	+= clk-nsp.o
+diff --git a/drivers/clk/bcm/clk-raspberrypi.c b/drivers/clk/bcm/clk-raspberrypi.c
+new file mode 100644
+index 000000000000..046efc822a59
+--- /dev/null
++++ b/drivers/clk/bcm/clk-raspberrypi.c
+@@ -0,0 +1,138 @@
++// SPDX-License-Identifier: GPL-2.0+
++/*
++ * Raspberry Pi CPU clock driver
++ *
++ * Copyright (C) 2018 Stefan Wahren <stefan.wahren@i2se.com>
++ */
++
++#include <linux/clk.h>
++#include <linux/clk-provider.h>
++#include <linux/device.h>
++#include <linux/err.h>
++#include <linux/module.h>
++#include <linux/of_device.h>
++#include <linux/platform_device.h>
++#include <linux/slab.h>
++#include <soc/bcm2835/raspberrypi-firmware.h>
++
++#define VCMSG_ID_ARM_CLOCK 0x000000003	/* Clock/Voltage ID's */
++
++struct rpi_cpu_clkgen {
++	struct clk_hw hw;
++	struct rpi_firmware *fw;
++};
++
++/* tag part of the message */
++struct prop {
++       u32 id;			/* the ID of the clock/voltage to get or set */
++       u32 val;			/* the value (e.g. rate (in Hz)) to set */
++} __packed;
++
++static int rpi_cpu_clock_property(struct rpi_firmware *fw, u32 tag, u32 *val)
++{
++	int ret;
++	struct prop msg = {
++		.id = VCMSG_ID_ARM_CLOCK,
++		.val = *val,
++	};
++
++	ret = rpi_firmware_property(fw, tag, &msg, sizeof(msg));
++	if (ret)
++		return ret;
++
++	*val = msg.val;
++
++	return 0;
++}
++
++static unsigned long rpi_cpu_get_rate(struct clk_hw *hw,
++				      unsigned long parent_rate)
++{
++	struct rpi_cpu_clkgen *cpu = container_of(hw, struct rpi_cpu_clkgen, hw);
++	u32 rate = 0;
++
++	rpi_cpu_clock_property(cpu->fw, RPI_FIRMWARE_GET_CLOCK_RATE, &rate);
++
++	return rate;
++}
++
++static long rpi_cpu_round_rate(struct clk_hw *hw, unsigned long rate,
++				     unsigned long *parent_rate)
++{
++	return rate;
++}
++
++static int rpi_cpu_set_rate(struct clk_hw *hw, unsigned long rate,
++			    unsigned long parent_rate)
++{
++	struct rpi_cpu_clkgen *cpu = container_of(hw, struct rpi_cpu_clkgen, hw);
++	u32 new_rate = rate;
++
++	return rpi_cpu_clock_property(cpu->fw, RPI_FIRMWARE_SET_CLOCK_RATE,
++				      &new_rate);
++}
++
++static const struct clk_ops rpi_cpu_ops = {
++	.recalc_rate = rpi_cpu_get_rate,
++	.round_rate = rpi_cpu_round_rate,
++	.set_rate = rpi_cpu_set_rate,
++};
++
++static int rpi_cpu_probe(struct platform_device *pdev)
++{
++	struct device *dev = &pdev->dev;
++	struct device_node *fw_node;
++	struct rpi_cpu_clkgen *cpu;
++	struct clk_init_data *init;
++	int ret;
++
++	cpu = devm_kzalloc(dev, sizeof(*cpu), GFP_KERNEL);
++	if (!cpu)
++		return -ENOMEM;
++
++	init = devm_kzalloc(dev, sizeof(*init), GFP_KERNEL);
++	if (!init)
++		return -ENOMEM;
++
++	fw_node = of_find_compatible_node(NULL, NULL,
++					  "raspberrypi,bcm2835-firmware");
++	if (!fw_node) {
++		dev_err(dev, "Missing firmware node\n");
++		return -ENOENT;
++	}
++
++	cpu->fw = rpi_firmware_get(fw_node);
++	of_node_put(fw_node);
++	if (!cpu->fw)
++		return -EPROBE_DEFER;
++
++	init->name = dev->of_node->name;
++	init->ops = &rpi_cpu_ops;
++
++	cpu->hw.init = init;
++	ret = devm_clk_hw_register(dev, &cpu->hw);
++	if (ret)
++		return ret;
++
++	return of_clk_add_hw_provider(dev->of_node, of_clk_hw_simple_get,
++				      &cpu->hw);
++}
++
++static const struct of_device_id rpi_cpu_of_match[] = {
++	{ .compatible = "raspberrypi,bcm2835-cpu", },
++	{},
++};
++MODULE_DEVICE_TABLE(of, rpi_cpu_of_match);
++
++static struct platform_driver rpi_cpu_driver = {
++	.driver = {
++		.name = "raspberrypi-cpu",
++		.of_match_table = rpi_cpu_of_match,
++	},
++	.probe		= rpi_cpu_probe,
++};
++builtin_platform_driver(rpi_cpu_driver);
++
++MODULE_AUTHOR("Stefan Wahren <stefan.wahren@i2se.com>");
++MODULE_DESCRIPTION("Raspberry Pi CPU clock driver");
++MODULE_LICENSE("GPL v2");
+-- 
+2.17.0
+