[[PATCHv4]] cpufreq for freescale mx51
yong.shen at linaro.org
yong.shen at linaro.org
Wed Oct 20 09:26:57 EDT 2010
From: Yong Shen <yong.shen at linaro.org>
Currently, only two operating points: 160Mhz and 800Mhz.
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 | 6 +-
arch/arm/mach-mx5/clock-mx51.c | 22 +++-
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 | 206 ++++++++++++++++++++++++++++++++
arch/arm/plat-mxc/include/mach/mxc.h | 11 ++-
10 files changed, 293 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..bdd625c 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 */
@@ -247,6 +248,9 @@ static void __init mxc_board_init(void)
{
struct pad_desc usbh1stp = MX51_PAD_USBH1_STP__USBH1_STP;
+#if defined(CONFIG_CPU_FREQ_IMX)
+ get_cpu_op = mx51_get_cpu_op;
+#endif
mxc_iomux_v3_setup_multiple_pads(mx51babbage_pads,
ARRAY_SIZE(mx51babbage_pads));
mxc_init_imx_uart();
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_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,},
+};
+
+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..039538e
--- /dev/null
+++ b/arch/arm/plat-mxc/cpufreq.c
@@ -0,0 +1,206 @@
+/*
+ * 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)
+
+struct cpu_op *(*get_cpu_op)(int *op);
+
+static int cpu_freq_khz_min;
+static int cpu_freq_khz_max;
+
+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;
+
+ 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);
+
+ 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;
+
+ if (!get_cpu_op)
+ 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);
+
+ 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) {
+ ret = -ENOMEM;
+ goto err1;
+ }
+
+ 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;
+
+ 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;
+
+ /* Manual states, that PLL stabilizes in two CLK32 periods */
+ policy->cpuinfo.transition_latency = 2 * NANOSECOND / CLK32_FREQ;
+
+ ret = cpufreq_frequency_table_cpuinfo(policy, imx_freq_table);
+
+ if (ret < 0) {
+ printk(KERN_ERR "%s: failed to register i.MXC CPUfreq \
+ with error code %d\n", __func__, ret);
+ goto err;
+ }
+
+ cpufreq_frequency_table_get_attr(imx_freq_table, policy->cpu);
+ return 0;
+err:
+ kfree(imx_freq_table);
+err1:
+ clk_put(cpu_clk);
+ return ret;
+}
+
+static int mxc_cpufreq_exit(struct cpufreq_policy *policy)
+{
+ cpufreq_frequency_table_put_attr(policy->cpu);
+
+ set_cpu_freq(cpu_freq_khz_max * 1000);
+ 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..084a856 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 +133,15 @@ extern unsigned int __mxc_cpu_type;
# define cpu_is_mxc91231() (0)
#endif
+#ifndef __ASSEMBLY__
+
+struct cpu_op {
+ u32 cpu_rate;
+};
+
+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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