[PATCH 6/6 v7] cpufreq, highbank: add support for highbank cpufreq
From: Shawn Guo <hidden>
Date: 2012-12-04 15:55:23
Also in:
linux-pm, lkml
On Tue, Dec 04, 2012 at 08:34:02AM -0600, Mark Langsdorf wrote:
Highbank processors depend on the external ECME to perform voltage management based on a requested frequency. Communication between the A9 cores and the ECME happens over the pl320 IPC channel. Signed-off-by: Mark Langsdorf <redacted> Cc: shawn.guo at linaro.org Cc: mturquette at ti.com --- Changes from v6 Removed devicetree bindings documentation. Restructured driver to use clk notifications. Core driver logic is now cpufreq-clk0.
Great. It saves some codes :)
quoted hunk ↗ jump to hunk
Changes from v5 Changed ipc_transmit() to pl320_ipc_transmit(). Changes from v4 Removed erroneous changes to arch/arm/Kconfig. Removed unnecessary changes to drivers/cpufreq/Kconfig.arm Alphabetized additions to arch/arm/mach-highbank/Kconfig Changed ipc call and header to match new ipc location in drivers/mailbox. Changes from v3 None. Changes from v2 Changed transition latency binding in code to match documentation. Changes from v1 Added highbank specific Kconfig changes. arch/arm/boot/dts/highbank.dts | 10 ++++ arch/arm/mach-highbank/Kconfig | 2 + drivers/cpufreq/Kconfig.arm | 16 ++++++ drivers/cpufreq/Makefile | 1 + drivers/cpufreq/highbank-cpufreq.c | 106 +++++++++++++++++++++++++++++++++++++ 5 files changed, 135 insertions(+) create mode 100644 drivers/cpufreq/highbank-cpufreq.cdiff --git a/arch/arm/boot/dts/highbank.dts b/arch/arm/boot/dts/highbank.dts index 0c6fc34..7c4c27d 100644 --- a/arch/arm/boot/dts/highbank.dts +++ b/arch/arm/boot/dts/highbank.dts@@ -36,6 +36,16 @@ next-level-cache = <&L2>; clocks = <&a9pll>; clock-names = "cpu"; + operating-points = < + /* kHz ignored */ + 1300000 1000000 + 1200000 1000000 + 1100000 1000000 + 800000 1000000 + 400000 1000000 + 200000 1000000 + >; + clock-latency = <100000>; }; cpu at 1 {diff --git a/arch/arm/mach-highbank/Kconfig b/arch/arm/mach-highbank/Kconfig index 2896881..b7862da 100644 --- a/arch/arm/mach-highbank/Kconfig +++ b/arch/arm/mach-highbank/Kconfig@@ -1,5 +1,7 @@ config ARCH_HIGHBANK bool "Calxeda ECX-1000 (Highbank)" if ARCH_MULTI_V7 + select ARCH_HAS_CPUFREQ + select ARCH_HAS_OPP select ARCH_WANT_OPTIONAL_GPIOLIB select ARM_AMBA select ARM_GICdiff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm index 5961e64..7aaac9f 100644 --- a/drivers/cpufreq/Kconfig.arm +++ b/drivers/cpufreq/Kconfig.arm@@ -76,3 +76,19 @@ config ARM_EXYNOS5250_CPUFREQ help This adds the CPUFreq driver for Samsung EXYNOS5250 SoC. + +config ARM_HIGHBANK_CPUFREQ + tristate "Calxeda Highbank-based" + depends on ARCH_HIGHBANK + select CPU_FREQ_TABLE + select GENERIC_CPUFREQ_CPU0 + select PM_OPP + select REGULATOR + + default m + help + This adds the CPUFreq driver for Calxeda Highbank SoC + based boards. + + If in doubt, say N. +diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile index 1bc90e1..9e8f12a 100644 --- a/drivers/cpufreq/Makefile +++ b/drivers/cpufreq/Makefile@@ -50,6 +50,7 @@ obj-$(CONFIG_ARM_EXYNOS4210_CPUFREQ) += exynos4210-cpufreq.o obj-$(CONFIG_ARM_EXYNOS4X12_CPUFREQ) += exynos4x12-cpufreq.o obj-$(CONFIG_ARM_EXYNOS5250_CPUFREQ) += exynos5250-cpufreq.o obj-$(CONFIG_ARM_OMAP2PLUS_CPUFREQ) += omap-cpufreq.o +obj-$(CONFIG_ARM_HIGHBANK_CPUFREQ) += highbank-cpufreq.o ################################################################################## # PowerPC platform driversdiff --git a/drivers/cpufreq/highbank-cpufreq.c b/drivers/cpufreq/highbank-cpufreq.c new file mode 100644 index 0000000..25ef437 --- /dev/null +++ b/drivers/cpufreq/highbank-cpufreq.c@@ -0,0 +1,106 @@ +/* + * Copyright (C) 2012 Calxeda, Inc. + * + * derived from cpufreq-cpu0 by Freescale Semiconductor
It's not any more, right?
+ * + * 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. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/clk.h> +#include <linux/cpu.h> +#include <linux/err.h> +#include <linux/of.h> +#include <linux/opp.h>
Do you need this header?
+#include <linux/slab.h> +#include <linux/mailbox.h> + +#define HB_CPUFREQ_CHANGE_NOTE 0x80000001 + +static struct device *cpu_dev; +static struct clk *cpu_clk;
These two now can be local variables hb_cpufreq_driver_init().
+
+static int hb_voltage_change(unsigned int freq)
+{
+ int i;
+ u32 msg[7];
+
+ msg[0] = HB_CPUFREQ_CHANGE_NOTE;
+ msg[1] = freq / 1000000;
+ for (i = 2; i < 7; i++)
+ msg[i] = 0;
+
+ return pl320_ipc_transmit(msg);
+}
+
+static int hb_cpufreq_clk_notify(struct notifier_block *nb,
+ unsigned long action, void *hclk)
+{
+ struct clk_notifier_data *clk_data = hclk;
+ int i = 0;
+
+ if (action == PRE_RATE_CHANGE) {
+ if (clk_data->new_rate > clk_data->old_rate)
+ while (hb_voltage_change(clk_data->new_rate))
+ if (i++ > 15)
+ return NOTIFY_STOP;
+ } else if (action == POST_RATE_CHANGE)
Add a {} pair for else block or remove {} for if?
+ if (clk_data->new_rate < clk_data->old_rate)
+ while (hb_voltage_change(clk_data->new_rate))
+ if (i++ > 15)
+ break;
+
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block hb_cpufreq_clk_nb = {
+ .notifier_call = hb_cpufreq_clk_notify,
+};
+
+static int __devinit hb_cpufreq_driver_init(void)Isn't there a big series removing __devinit from the kernel tree as CONFIG_HOTPLUG is going away? Shawn
+{
+ struct device_node *np;
+ int ret;
+
+ np = of_find_node_by_path("/cpus/cpu at 0");
+ if (!np) {
+ pr_err("failed to find highbank cpufreq node\n");
+ return -ENOENT;
+ }
+
+ cpu_dev = get_cpu_device(0);
+ if (!cpu_dev) {
+ pr_err("failed to get highbank cpufreq device\n");
+ ret = -ENODEV;
+ goto out_put_node;
+ }
+
+ cpu_dev->of_node = np;
+
+ cpu_clk = clk_get(cpu_dev, NULL);
+ if (IS_ERR(cpu_clk)) {
+ ret = PTR_ERR(cpu_clk);
+ pr_err("failed to get cpu0 clock: %d\n", ret);
+ goto out_put_node;
+ }
+
+ ret = clk_notifier_register(cpu_clk, &hb_cpufreq_clk_nb);
+ if (ret) {
+ pr_err("failed to register clk notifier: %d\n", ret);
+ goto out_put_node;
+ }
+
+out_put_node:
+ of_node_put(np);
+ return ret;
+}
+late_initcall(hb_cpufreq_driver_init);
+
+MODULE_AUTHOR("Mark Langsdorf [off-list ref]");
+MODULE_DESCRIPTION("Calxeda Highbank cpufreq driver");
+MODULE_LICENSE("GPL");
--
1.7.11.7