[PATCHv3] cpufreq for freescale mx51
Sascha Hauer
s.hauer at pengutronix.de
Mon Oct 18 06:13:14 EDT 2010
On Mon, Oct 18, 2010 at 04:21:45PM +0800, yong.shen at linaro.org wrote:
> From: Yong Shen <yong.shen at linaro.org>
>
> the operating points are tested on babbage 3.0
>
> Signed-off-by: Yong Shen <yong.shen at linaro.org>
> ---
> arch/arm/Kconfig | 6 +
> arch/arm/mach-mx5/Kconfig | 1 +
> arch/arm/mach-mx5/Makefile | 1 +
> arch/arm/mach-mx5/board-mx51_babbage.c | 12 ++-
> arch/arm/mach-mx5/clock-mx51.c | 22 +++-
> arch/arm/mach-mx5/cpu.c | 2 +
> arch/arm/mach-mx5/cpu_op-mx51.c | 29 +++++
> arch/arm/mach-mx5/cpu_op-mx51.h | 14 +++
> arch/arm/plat-mxc/Makefile | 1 +
> arch/arm/plat-mxc/cpufreq.c | 202 ++++++++++++++++++++++++++++++++
> arch/arm/plat-mxc/include/mach/mxc.h | 20 +++-
> 11 files changed, 306 insertions(+), 4 deletions(-)
> create mode 100644 arch/arm/mach-mx5/cpu_op-mx51.c
> create mode 100644 arch/arm/mach-mx5/cpu_op-mx51.h
> create mode 100644 arch/arm/plat-mxc/cpufreq.c
>
> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> index e4ea9cb..d9ad605 100644
> --- a/arch/arm/Kconfig
> +++ b/arch/arm/Kconfig
> @@ -1692,6 +1692,12 @@ if ARCH_HAS_CPUFREQ
>
> source "drivers/cpufreq/Kconfig"
>
> +config CPU_FREQ_IMX
> + tristate "CPUfreq driver for i.MX CPUs"
> + depends on ARCH_MXC && CPU_FREQ
> + help
> + This enables the CPUfreq driver for i.MX CPUs.
> +
> config CPU_FREQ_SA1100
> bool
>
> diff --git a/arch/arm/mach-mx5/Kconfig b/arch/arm/mach-mx5/Kconfig
> index 0848db5..7a621b4 100644
> --- a/arch/arm/mach-mx5/Kconfig
> +++ b/arch/arm/mach-mx5/Kconfig
> @@ -5,6 +5,7 @@ config ARCH_MX51
> default y
> select MXC_TZIC
> select ARCH_MXC_IOMUX_V3
> + select ARCH_HAS_CPUFREQ
>
> comment "MX5 platforms:"
>
> diff --git a/arch/arm/mach-mx5/Makefile b/arch/arm/mach-mx5/Makefile
> index 86c66e7..2fadac5 100644
> --- a/arch/arm/mach-mx5/Makefile
> +++ b/arch/arm/mach-mx5/Makefile
> @@ -5,6 +5,7 @@
> # Object file lists.
> obj-y := cpu.o mm.o clock-mx51.o devices.o
>
> +obj-$(CONFIG_CPU_FREQ_IMX) += cpu_op-mx51.o
> obj-$(CONFIG_MACH_MX51_BABBAGE) += board-mx51_babbage.o
> obj-$(CONFIG_MACH_MX51_3DS) += board-mx51_3ds.o
> obj-$(CONFIG_MACH_EUKREA_CPUIMX51) += board-cpuimx51.o
> diff --git a/arch/arm/mach-mx5/board-mx51_babbage.c b/arch/arm/mach-mx5/board-mx51_babbage.c
> index 6e384d9..74c796f 100644
> --- a/arch/arm/mach-mx5/board-mx51_babbage.c
> +++ b/arch/arm/mach-mx5/board-mx51_babbage.c
> @@ -1,5 +1,5 @@
> /*
> - * Copyright 2009 Freescale Semiconductor, Inc. All Rights Reserved.
> + * Copyright 2009-2010 Freescale Semiconductor, Inc. All Rights Reserved.
> * Copyright (C) 2009-2010 Amit Kucheria <amit.kucheria at canonical.com>
> *
> * The code contained herein is licensed under the GNU General Public
> @@ -32,6 +32,7 @@
> #include <asm/mach/time.h>
>
> #include "devices.h"
> +#include "cpu_op-mx51.h"
>
> #define BABBAGE_USB_HUB_RESET (0*32 + 7) /* GPIO_1_7 */
> #define BABBAGE_USBH1_STP (0*32 + 27) /* GPIO_1_27 */
> @@ -279,8 +280,17 @@ static struct sys_timer mxc_timer = {
> .init = mx51_babbage_timer_init,
> };
>
> +static void __init fixup_mxc_board(struct machine_desc *desc, struct tag *tags,
> + char **cmdline, struct meminfo *mi)
> +{
> +#if defined(CONFIG_CPU_FREQ_IMX)
> + get_cpu_op = mx51_get_cpu_op;
> +#endif
> +}
> +
Why has this to live in .fixup? .init_machine should be fine here.
> MACHINE_START(MX51_BABBAGE, "Freescale MX51 Babbage Board")
> /* Maintainer: Amit Kucheria <amit.kucheria at canonical.com> */
> + .fixup = fixup_mxc_board,
> .phys_io = MX51_AIPS1_BASE_ADDR,
> .io_pg_offst = ((MX51_AIPS1_BASE_ADDR_VIRT) >> 18) & 0xfffc,
> .boot_params = PHYS_OFFSET + 0x100,
> diff --git a/arch/arm/mach-mx5/clock-mx51.c b/arch/arm/mach-mx5/clock-mx51.c
> index 6af69de..f89d8a0 100644
> --- a/arch/arm/mach-mx5/clock-mx51.c
> +++ b/arch/arm/mach-mx5/clock-mx51.c
> @@ -330,7 +330,7 @@ static int _clk_lp_apm_set_parent(struct clk *clk, struct clk *parent)
> return 0;
> }
>
> -static unsigned long clk_arm_get_rate(struct clk *clk)
> +static unsigned long clk_cpu_get_rate(struct clk *clk)
> {
> u32 cacrr, div;
> unsigned long parent_rate;
> @@ -342,6 +342,22 @@ static unsigned long clk_arm_get_rate(struct clk *clk)
> return parent_rate / div;
> }
>
> +static int clk_cpu_set_rate(struct clk *clk, unsigned long rate)
> +{
> + u32 reg, cpu_podf;
> + unsigned long parent_rate;
> +
> + parent_rate = clk_get_rate(clk->parent);
> + cpu_podf = parent_rate / rate - 1;
> + /* use post divider to change freq */
> + reg = __raw_readl(MXC_CCM_CACRR);
> + reg &= ~MXC_CCM_CACRR_ARM_PODF_MASK;
> + reg |= cpu_podf << MXC_CCM_CACRR_ARM_PODF_OFFSET;
> + __raw_writel(reg, MXC_CCM_CACRR);
> +
> + return 0;
> +}
> +
> static int _clk_periph_apm_set_parent(struct clk *clk, struct clk *parent)
> {
> u32 reg, mux;
> @@ -693,7 +709,8 @@ static struct clk periph_apm_clk = {
>
> static struct clk cpu_clk = {
> .parent = &pll1_sw_clk,
> - .get_rate = clk_arm_get_rate,
> + .get_rate = clk_cpu_get_rate,
> + .set_rate = clk_cpu_set_rate,
> };
>
> static struct clk ahb_clk = {
> @@ -837,6 +854,7 @@ static struct clk_lookup lookups[] = {
> _REGISTER_CLOCK("fsl-usb2-udc", "usb", usboh3_clk)
> _REGISTER_CLOCK("fsl-usb2-udc", "usb_ahb", ahb_clk)
> _REGISTER_CLOCK("imx-keypad.0", NULL, kpp_clk)
> + _REGISTER_CLOCK(NULL, "cpu_clk", cpu_clk)
> };
>
> static void clk_tree_init(void)
> diff --git a/arch/arm/mach-mx5/cpu.c b/arch/arm/mach-mx5/cpu.c
> index 2d37785..f3fe51a 100644
> --- a/arch/arm/mach-mx5/cpu.c
> +++ b/arch/arm/mach-mx5/cpu.c
> @@ -22,6 +22,8 @@ static int cpu_silicon_rev = -1;
>
> #define SI_REV 0x48
>
> +struct cpu_op *(*get_cpu_op)(int *op);
> +
> static void query_silicon_parameter(void)
> {
> void __iomem *rom = ioremap(MX51_IROM_BASE_ADDR, MX51_IROM_SIZE);
> diff --git a/arch/arm/mach-mx5/cpu_op-mx51.c b/arch/arm/mach-mx5/cpu_op-mx51.c
> new file mode 100644
> index 0000000..9d34c3d
> --- /dev/null
> +++ b/arch/arm/mach-mx5/cpu_op-mx51.c
> @@ -0,0 +1,29 @@
> +/*
> + * Copyright (C) 2010 Freescale Semiconductor, Inc. All Rights Reserved.
> + */
> +
> +/*
> + * The code contained herein is licensed under the GNU General Public
> + * License. You may obtain a copy of the GNU General Public License
> + * Version 2 or later at the following locations:
> + *
> + * http://www.opensource.org/licenses/gpl-license.html
> + * http://www.gnu.org/copyleft/gpl.html
> + */
> +
> +#include <linux/types.h>
> +#include <mach/hardware.h>
> +#include <linux/kernel.h>
> +
> +static struct cpu_op mx51_cpu_op[] = {
> + {
> + .cpu_rate = 160000000,},
> + {
> + .cpu_rate = 800000000,},
> +};
Why did you remove the values between 800MHz and 160MHz? 400MHz and
200Mhz should work also, no?
> +
> +struct cpu_op *mx51_get_cpu_op(int *op)
> +{
> + *op = ARRAY_SIZE(mx51_cpu_op);
> + return mx51_cpu_op;
> +}
> diff --git a/arch/arm/mach-mx5/cpu_op-mx51.h b/arch/arm/mach-mx5/cpu_op-mx51.h
> new file mode 100644
> index 0000000..97477fe
> --- /dev/null
> +++ b/arch/arm/mach-mx5/cpu_op-mx51.h
> @@ -0,0 +1,14 @@
> +/*
> + * Copyright (C) 2010 Freescale Semiconductor, Inc. All Rights Reserved.
> + */
> +
> +/*
> + * The code contained herein is licensed under the GNU General Public
> + * License. You may obtain a copy of the GNU General Public License
> + * Version 2 or later at the following locations:
> + *
> + * http://www.opensource.org/licenses/gpl-license.html
> + * http://www.gnu.org/copyleft/gpl.html
> + */
> +
> +extern struct cpu_op *mx51_get_cpu_op(int *op);
> diff --git a/arch/arm/plat-mxc/Makefile b/arch/arm/plat-mxc/Makefile
> index 78d405e..a833d38 100644
> --- a/arch/arm/plat-mxc/Makefile
> +++ b/arch/arm/plat-mxc/Makefile
> @@ -16,6 +16,7 @@ obj-$(CONFIG_MXC_ULPI) += ulpi.o
> obj-$(CONFIG_ARCH_MXC_AUDMUX_V1) += audmux-v1.o
> obj-$(CONFIG_ARCH_MXC_AUDMUX_V2) += audmux-v2.o
> obj-$(CONFIG_MXC_DEBUG_BOARD) += 3ds_debugboard.o
> +obj-$(CONFIG_CPU_FREQ_IMX) += cpufreq.o
> ifdef CONFIG_SND_IMX_SOC
> obj-y += ssi-fiq.o
> obj-y += ssi-fiq-ksym.o
> diff --git a/arch/arm/plat-mxc/cpufreq.c b/arch/arm/plat-mxc/cpufreq.c
> new file mode 100644
> index 0000000..9cabeb9
> --- /dev/null
> +++ b/arch/arm/plat-mxc/cpufreq.c
> @@ -0,0 +1,202 @@
> +/*
> + * Copyright (C) 2010 Freescale Semiconductor, Inc. All Rights Reserved.
> + */
> +
> +/*
> + * The code contained herein is licensed under the GNU General Public
> + * License. You may obtain a copy of the GNU General Public License
> + * Version 2 or later at the following locations:
> + *
> + * http://www.opensource.org/licenses/gpl-license.html
> + * http://www.gnu.org/copyleft/gpl.html
> + */
> +
> +/*
> + * A driver for the Freescale Semiconductor i.MXC CPUfreq module.
> + * The CPUFREQ driver is for controling CPU frequency. It allows you to change
> + * the CPU clock speed on the fly.
> + */
> +
> +#include <linux/cpufreq.h>
> +#include <linux/clk.h>
> +#include <linux/err.h>
> +#include <linux/slab.h>
> +#include <mach/hardware.h>
> +#include <mach/clock.h>
> +
> +#define CLK32_FREQ 32768
> +#define NANOSECOND (1000 * 1000 * 1000)
> +
> +static int cpu_freq_khz_min;
> +static int cpu_freq_khz_max;
> +static int arm_normal_clk;
> +
> +static struct clk *cpu_clk;
> +static struct cpufreq_frequency_table *imx_freq_table;
> +
> +static int cpu_op_nr;
> +static struct cpu_op *cpu_op_tbl;
> +
> +static int set_cpu_freq(int freq)
> +{
> + int ret = 0;
> + int org_cpu_rate;
> +
> + org_cpu_rate = clk_get_rate(cpu_clk);
> + if (org_cpu_rate == freq)
> + return ret;
You already checked this in mxc_set_target. Once is enough.
> +
> + ret = clk_set_rate(cpu_clk, freq);
> + if (ret != 0) {
> + printk(KERN_DEBUG "cannot set CPU clock rate\n");
> + return ret;
> + }
> +
> + return ret;
> +}
> +
> +static int mxc_verify_speed(struct cpufreq_policy *policy)
> +{
> + if (policy->cpu != 0)
> + return -EINVAL;
> +
> + return cpufreq_frequency_table_verify(policy, imx_freq_table);
> +}
> +
> +static unsigned int mxc_get_speed(unsigned int cpu)
> +{
> + if (cpu)
> + return 0;
> +
> + return clk_get_rate(cpu_clk) / 1000;
> +}
> +
> +static int mxc_set_target(struct cpufreq_policy *policy,
> + unsigned int target_freq, unsigned int relation)
> +{
> + struct cpufreq_freqs freqs;
> + int freq_Hz;
> + int ret = 0;
> + unsigned int index;
> +
> + cpufreq_frequency_table_target(policy, imx_freq_table,
> + target_freq, relation, &index);
> + freq_Hz = imx_freq_table[index].frequency * 1000;
> +
> + freqs.old = clk_get_rate(cpu_clk) / 1000;
> + freqs.new = freq_Hz / 1000;
> + freqs.cpu = 0;
> + freqs.flags = 0;
> + cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
> +
> + if (freqs.old != freqs.new)
> + ret = set_cpu_freq(freq_Hz);
> +
> + cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
> +
> + return ret;
> +}
> +
> +static int __init mxc_cpufreq_init(struct cpufreq_policy *policy)
> +{
> + int ret;
> + int i;
> +
> + printk(KERN_INFO "i.MXC CPU frequency driver\n");
> +
> + if (policy->cpu != 0)
> + return -EINVAL;
> +
> + cpu_clk = clk_get(NULL, "cpu_clk");
> + if (IS_ERR(cpu_clk)) {
> + printk(KERN_ERR "%s: failed to get cpu clock\n", __func__);
> + return PTR_ERR(cpu_clk);
> + }
> +
> + cpu_op_tbl = get_cpu_op(&cpu_op_nr);
This will crash every board except the babbage board which happens to
set this function pointer.
> +
> + cpu_freq_khz_min = cpu_op_tbl[0].cpu_rate / 1000;
> + cpu_freq_khz_max = cpu_op_tbl[0].cpu_rate / 1000;
> +
> + imx_freq_table = kmalloc(
> + sizeof(struct cpufreq_frequency_table) * (cpu_op_nr + 1),
> + GFP_KERNEL);
> + if (!imx_freq_table) {
> + clk_put(cpu_clk);
> + return -ENOMEM;
> + }
> +
> + for (i = 0; i < cpu_op_nr; i++) {
> + imx_freq_table[i].index = i;
> + imx_freq_table[i].frequency =
> + cpu_op_tbl[i].cpu_rate / 1000;
unnecessary line break.
> +
> + if ((cpu_op_tbl[i].cpu_rate / 1000) < cpu_freq_khz_min)
> + cpu_freq_khz_min = cpu_op_tbl[i].cpu_rate / 1000;
> +
> + if ((cpu_op_tbl[i].cpu_rate / 1000) > cpu_freq_khz_max)
> + cpu_freq_khz_max = cpu_op_tbl[i].cpu_rate / 1000;
> + }
> +
> + imx_freq_table[i].index = i;
> + imx_freq_table[i].frequency = CPUFREQ_TABLE_END;
> +
> + policy->cur = clk_get_rate(cpu_clk) / 1000;
> + policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
> + policy->min = policy->cpuinfo.min_freq = cpu_freq_khz_min;
> + policy->max = policy->cpuinfo.max_freq = cpu_freq_khz_max;
> +
> + arm_normal_clk = cpu_freq_khz_max * 1000;
> +
> + /* Manual states, that PLL stabilizes in two CLK32 periods */
> + policy->cpuinfo.transition_latency = 2 / CLK32_FREQ * NANOSECOND;
These are evaluated from left to right, so this is 0.
> +
> + ret = cpufreq_frequency_table_cpuinfo(policy, imx_freq_table);
> +
> + if (ret < 0) {
> + clk_put(cpu_clk);
> + printk(KERN_ERR "%s: failed to register i.MXC CPUfreq\n",
> + __func__);
> + return ret;
> + }
You forget to kfree the resources allocated above. This is one of the
valid usecases for goto, see a driver probe function of your choice how
they do this right.
Also, the actual error code is of interest in this printk.
> +
> + cpufreq_frequency_table_get_attr(imx_freq_table, policy->cpu);
> + return 0;
> +}
> +
> +static int mxc_cpufreq_exit(struct cpufreq_policy *policy)
> +{
> + cpufreq_frequency_table_put_attr(policy->cpu);
> +
> + set_cpu_freq(arm_normal_clk);
As said before, please get rid of arm_normal_clk.
> + clk_put(cpu_clk);
> + kfree(imx_freq_table);
> + return 0;
> +}
> +
> +static struct cpufreq_driver mxc_driver = {
> + .flags = CPUFREQ_STICKY,
> + .verify = mxc_verify_speed,
> + .target = mxc_set_target,
> + .get = mxc_get_speed,
> + .init = mxc_cpufreq_init,
> + .exit = mxc_cpufreq_exit,
> + .name = "imx",
> +};
> +
> +static int __devinit mxc_cpufreq_driver_init(void)
> +{
> + return cpufreq_register_driver(&mxc_driver);
> +}
> +
> +static void mxc_cpufreq_driver_exit(void)
> +{
> + cpufreq_unregister_driver(&mxc_driver);
> +}
> +
> +module_init(mxc_cpufreq_driver_init);
> +module_exit(mxc_cpufreq_driver_exit);
> +
> +MODULE_AUTHOR("Freescale Semiconductor Inc. Yong Shen <yong.shen at linaro.org>");
> +MODULE_DESCRIPTION("CPUfreq driver for i.MX");
> +MODULE_LICENSE("GPL");
> diff --git a/arch/arm/plat-mxc/include/mach/mxc.h b/arch/arm/plat-mxc/include/mach/mxc.h
> index a790bf2..888dddc 100644
> --- a/arch/arm/plat-mxc/include/mach/mxc.h
> +++ b/arch/arm/plat-mxc/include/mach/mxc.h
> @@ -1,5 +1,5 @@
> /*
> - * Copyright 2004-2007 Freescale Semiconductor, Inc. All Rights Reserved.
> + * Copyright 2004-2007, 2010 Freescale Semiconductor, Inc. All Rights Reserved.
> * Copyright (C) 2008 Juergen Beisert (kernel at pengutronix.de)
> *
> * This program is free software; you can redistribute it and/or
> @@ -133,6 +133,24 @@ extern unsigned int __mxc_cpu_type;
> # define cpu_is_mxc91231() (0)
> #endif
>
> +#ifndef __ASSEMBLY__
> +
> +struct cpu_op {
> + u32 pll_reg;
> + u32 pll_rate;
> + u32 cpu_rate;
> + u32 pdr0_reg;
> + u32 pdf;
> + u32 mfi;
> + u32 mfd;
> + u32 mfn;
> + u32 cpu_voltage;
> + u32 cpu_podf;
Many unused fields here.
> +};
> +
> +extern struct cpu_op *(*get_cpu_op)(int *op);
> +#endif
> +
> #if defined(CONFIG_ARCH_MX3) || defined(CONFIG_ARCH_MX2)
> /* These are deprecated, use mx[23][157]_setup_weimcs instead. */
> #define CSCR_U(n) (IO_ADDRESS(WEIM_BASE_ADDR + n * 0x10))
> --
> 1.6.3.3
>
>
> _______________________________________________
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>
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