[PATCH] cpufreq for freescale mx51
Amit Kucheria
amit.kucheria at linaro.org
Thu Oct 7 04:03:58 EDT 2010
Some comments inline.
On 10 Oct 07, Yong Shen wrote:
> From: Yong Shen <yong.shen at linaro.org>
>
> it is 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 | 2 +-
> arch/arm/mach-mx5/board-mx51_babbage.c | 10 ++-
> arch/arm/mach-mx5/clock-mx51.c | 54 ++++++++
> arch/arm/mach-mx5/cpu.c | 2 +
> arch/arm/mach-mx5/cpu_wp-mx51.c | 42 ++++++
> arch/arm/mach-mx5/cpu_wp-mx51.h | 14 ++
> arch/arm/plat-mxc/Makefile | 2 +
> arch/arm/plat-mxc/cpufreq.c | 232 ++++++++++++++++++++++++++++++++
> arch/arm/plat-mxc/include/mach/mxc.h | 20 +++-
> 11 files changed, 382 insertions(+), 3 deletions(-)
> create mode 100644 arch/arm/mach-mx5/cpu_wp-mx51.c
> create mode 100644 arch/arm/mach-mx5/cpu_wp-mx51.h
> create mode 100644 arch/arm/plat-mxc/cpufreq.c
>
> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> index d203b84..9ea6c37 100644
> --- a/arch/arm/Kconfig
> +++ b/arch/arm/Kconfig
> @@ -1690,6 +1690,12 @@ 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..673daba 100644
> --- a/arch/arm/mach-mx5/Makefile
> +++ b/arch/arm/mach-mx5/Makefile
> @@ -3,7 +3,7 @@
> #
>
> # Object file lists.
> -obj-y := cpu.o mm.o clock-mx51.o devices.o
> +obj-y := cpu.o mm.o clock-mx51.o devices.o cpu_wp-mx51.o
By hardcoding cpu_wp-mx51 here, you are making the assumption that even if
cpufreq is turned off, you'll still need the entire WP table to set the
cpu frequency. Why can't this be handled transparently in the clock code? If
the clock code does the calculations, every board doesn't need to first setup
calls to get_cpu_wp.
> obj-$(CONFIG_MACH_MX51_BABBAGE) += board-mx51_babbage.o
> obj-$(CONFIG_MACH_MX51_3DS) += board-mx51_3ds.o
> diff --git a/arch/arm/mach-mx5/board-mx51_babbage.c b/arch/arm/mach-mx5/board-mx51_babbage.c
> index 6e384d9..74627d2 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_wp-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 +280,15 @@ 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)
> +{
> + get_cpu_wp = mx51_get_cpu_wp;
> +}
> +
> 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..0709a64 100644
> --- a/arch/arm/mach-mx5/clock-mx51.c
> +++ b/arch/arm/mach-mx5/clock-mx51.c
> @@ -28,6 +28,10 @@
> static unsigned long external_high_reference, external_low_reference;
> static unsigned long oscillator_reference, ckih2_reference;
>
> +static int cpu_wp_nr;
> +static int cpu_curr_wp;
> +static struct cpu_wp *cpu_wp_tbl;
> +
> static struct clk osc_clk;
> static struct clk pll1_main_clk;
> static struct clk pll1_sw_clk;
> @@ -39,6 +43,8 @@ static struct clk ahb_clk;
> static struct clk ipg_clk;
> static struct clk usboh3_clk;
>
> +DEFINE_SPINLOCK(clk_lock);
> +
> #define MAX_DPLL_WAIT_TRIES 1000 /* 1000 * udelay(1) = 1ms */
>
> static int _clk_ccgr_enable(struct clk *clk)
> @@ -330,6 +336,37 @@ static int _clk_lp_apm_set_parent(struct clk *clk, struct clk *parent)
> return 0;
> }
>
> +/*!
> + * Setup cpu clock based on working point.
> + * @param wp cpu freq working point
> + * @return 0 on success or error code on failure.
> + */
> +static int cpu_clk_set_wp(int wp)
> +{
> + struct cpu_wp *p;
> + u32 reg;
> + unsigned long flags;
> +
> + if (wp == cpu_curr_wp)
> + return 0;
> +
> + p = &cpu_wp_tbl[wp];
> +
> + /*use post divider to change freq
> + */
Fix comment to one-line
>
> + spin_lock_irqsave(&clk_lock, flags);
> +
> + reg = __raw_readl(MXC_CCM_CACRR);
> + reg &= ~MXC_CCM_CACRR_ARM_PODF_MASK;
> + reg |= cpu_wp_tbl[wp].cpu_podf << MXC_CCM_CACRR_ARM_PODF_OFFSET;
> + __raw_writel(reg, MXC_CCM_CACRR);
> +
> + spin_unlock_irqrestore(&clk_lock, flags);
> + cpu_curr_wp = wp;
> +
> + return 0;
> +}
> +
> static unsigned long clk_arm_get_rate(struct clk *clk)
> {
> u32 cacrr, div;
> @@ -342,6 +379,20 @@ 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 i;
> + for (i = 0; i < cpu_wp_nr; i++) {
> + if (rate == cpu_wp_tbl[i].cpu_rate)
> + break;
> + }
> + if (i >= cpu_wp_nr)
> + return -EINVAL;
> + cpu_clk_set_wp(i);
> +
> + return 0;
> +}
> +
Why use cpu_clk_set_wp when CPUFREQ is not compiled in? You could do the
calculations here itself and remove the dependency on the WP table.
> static int _clk_periph_apm_set_parent(struct clk *clk, struct clk *parent)
> {
> u32 reg, mux;
> @@ -694,6 +745,7 @@ static struct clk periph_apm_clk = {
> static struct clk cpu_clk = {
> .parent = &pll1_sw_clk,
> .get_rate = clk_arm_get_rate,
> + .set_rate = _clk_cpu_set_rate,
> };
>
> static struct clk ahb_clk = {
> @@ -837,6 +889,7 @@ 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)
> @@ -868,6 +921,7 @@ int __init mx51_clocks_init(unsigned long ckil, unsigned long osc,
> external_high_reference = ckih1;
> ckih2_reference = ckih2;
> oscillator_reference = osc;
> + cpu_wp_tbl = get_cpu_wp(&cpu_wp_nr);
>
> for (i = 0; i < ARRAY_SIZE(lookups); i++)
> clkdev_add(&lookups[i]);
> diff --git a/arch/arm/mach-mx5/cpu.c b/arch/arm/mach-mx5/cpu.c
> index 2d37785..83add9c 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_wp *(*get_cpu_wp)(int *wp);
> +
> 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_wp-mx51.c b/arch/arm/mach-mx5/cpu_wp-mx51.c
> new file mode 100644
> index 0000000..51bde45
> --- /dev/null
> +++ b/arch/arm/mach-mx5/cpu_wp-mx51.c
> @@ -0,0 +1,42 @@
> +/*
> + * 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>
> +
> +static struct cpu_wp cpu_wp_auto[] = {
> + {
> + .pll_rate = 800000000,
> + .cpu_rate = 160000000,
> + .pdf = 4,
> + .mfi = 8,
> + .mfd = 2,
> + .mfn = 1,
> + .cpu_podf = 4,
> + .cpu_voltage = 850000,},
> + {
> + .pll_rate = 800000000,
> + .cpu_rate = 800000000,
> + .pdf = 0,
> + .mfi = 8,
> + .mfd = 2,
> + .mfn = 1,
> + .cpu_podf = 0,
> + .cpu_voltage = 1100000,},
> +};
> +
> +struct cpu_wp *mx51_get_cpu_wp(int *wp)
> +{
> + *wp = sizeof(cpu_wp_auto) / sizeof(struct cpu_wp);
> + return cpu_wp_auto;
> +}
> diff --git a/arch/arm/mach-mx5/cpu_wp-mx51.h b/arch/arm/mach-mx5/cpu_wp-mx51.h
> new file mode 100644
> index 0000000..8038b62
> --- /dev/null
> +++ b/arch/arm/mach-mx5/cpu_wp-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_wp *mx51_get_cpu_wp(int *wp);
> diff --git a/arch/arm/plat-mxc/Makefile b/arch/arm/plat-mxc/Makefile
> index 78d405e..0b8464f 100644
> --- a/arch/arm/plat-mxc/Makefile
> +++ b/arch/arm/plat-mxc/Makefile
> @@ -16,6 +16,8 @@ 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
> +# CPU FREQ support
> +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..dfb1dde
> --- /dev/null
> +++ b/arch/arm/plat-mxc/cpufreq.c
> @@ -0,0 +1,232 @@
> +/*
> + * 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/types.h>
> +#include <linux/kernel.h>
> +#include <linux/cpufreq.h>
> +#include <linux/init.h>
> +#include <linux/proc_fs.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/clk.h>
> +#include <linux/delay.h>
> +#include <linux/io.h>
> +#include <mach/hardware.h>
> +#include <asm/setup.h>
> +#include <mach/clock.h>
> +#include <asm/cacheflush.h>
> +#include <linux/hrtimer.h>
> +
> +static int cpu_freq_khz_min;
> +static int cpu_freq_khz_max;
> +static int arm_lpm_clk;
> +static int arm_normal_clk;
> +static int cpufreq_suspended;
> +
> +static struct clk *cpu_clk;
> +static struct cpufreq_frequency_table imx_freq_table[4];
> +
> +static int cpu_wp_nr;
> +static struct cpu_wp *cpu_wp_tbl;
> +
> +static int set_cpu_freq(int freq)
> +{
> + int ret = 0;
> + int org_cpu_rate;
> + int gp_volt = 0;
> + int i;
> +
> + org_cpu_rate = clk_get_rate(cpu_clk);
> + if (org_cpu_rate == freq)
> + return ret;
> +
> + for (i = 0; i < cpu_wp_nr; i++) {
> + if (freq == cpu_wp_tbl[i].cpu_rate)
> + gp_volt = cpu_wp_tbl[i].cpu_voltage;
> + }
> +
> + if (gp_volt == 0)
> + return ret;
> +
> + 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;
> +
> + if (cpufreq_suspended) {
> + target_freq = clk_get_rate(cpu_clk) / 1000;
> + cpufreq_frequency_table_target(policy, imx_freq_table,
> + target_freq, relation, &index);
> + freq_Hz = imx_freq_table[index].frequency * 1000;
> +
> + if (freq_Hz == arm_lpm_clk)
> + freqs.old = cpu_wp_tbl[cpu_wp_nr - 2].cpu_rate / 1000;
> + else
> + freqs.old = arm_lpm_clk / 1000;
> +
> + freqs.new = freq_Hz / 1000;
> + freqs.cpu = 0;
> + freqs.flags = 0;
> + cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
> + cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
> + return ret;
> + }
> +
> + 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);
> + }
> +
> + /* Set the current working point. */
> + cpu_wp_tbl = get_cpu_wp(&cpu_wp_nr);
> +
> + cpu_freq_khz_min = cpu_wp_tbl[0].cpu_rate / 1000;
> + cpu_freq_khz_max = cpu_wp_tbl[0].cpu_rate / 1000;
> +
> + for (i = 0; i < cpu_wp_nr; i++) {
> + imx_freq_table[i].index = i;
> + imx_freq_table[i].frequency =
> + cpu_wp_tbl[i].cpu_rate / 1000;
> +
> + if ((cpu_wp_tbl[i].cpu_rate / 1000) < cpu_freq_khz_min)
> + cpu_freq_khz_min = cpu_wp_tbl[i].cpu_rate / 1000;
> +
> + if ((cpu_wp_tbl[i].cpu_rate / 1000) > cpu_freq_khz_max)
> + cpu_freq_khz_max = cpu_wp_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_lpm_clk = cpu_freq_khz_min * 1000;
> + arm_normal_clk = cpu_freq_khz_max * 1000;
> +
> + /* Manual states, that PLL stabilizes in two CLK32 periods */
> + policy->cpuinfo.transition_latency = 10;
> +
> + 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;
> + }
> +
> + 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);
> +
> + /* Reset CPU to 665MHz */
> + set_cpu_freq(arm_normal_clk);
> + clk_put(cpu_clk);
> + 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..31df991 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 2004-2010 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_wp {
> + 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;
> +};
> +
> +extern struct cpu_wp *(*get_cpu_wp)(int *wp);
> +#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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