[PATCH 2/2] cpufreq: tegra: Re-model Tegra cpufreq driver
Bill Huang
bilhuang at nvidia.com
Wed Sep 11 07:19:14 EDT 2013
Re-model Tegra cpufreq driver to support all Tegra series of SoCs.
* Make tegra-cpufreq.c a generic Tegra cpufreq driver.
* Move Tegra20 specific codes into tegra20-cpufreq.c.
* Bind Tegra cpufreq dirver with a fake device so defer probe would work
when we're going to get regulator in the driver to support voltage
scaling (DVFS).
* Call tegra_cpufreq_init() in Tegra machine code specifically so it
won't be called in multi-platform kernel which is not running on Tegra
SoCs.
Signed-off-by: Bill Huang <bilhuang at nvidia.com>
---
arch/arm/mach-tegra/common.c | 2 +
drivers/cpufreq/Kconfig.arm | 16 +++-
drivers/cpufreq/Makefile | 1 +
drivers/cpufreq/tegra-cpufreq.c | 178 ++++++++++++++++++-------------------
drivers/cpufreq/tegra-cpufreq.h | 37 ++++++++
drivers/cpufreq/tegra20-cpufreq.c | 133 +++++++++++++++++++++++++++
include/linux/tegra-soc.h | 11 ++-
7 files changed, 281 insertions(+), 97 deletions(-)
create mode 100644 drivers/cpufreq/tegra-cpufreq.h
create mode 100644 drivers/cpufreq/tegra20-cpufreq.c
diff --git a/arch/arm/mach-tegra/common.c b/arch/arm/mach-tegra/common.c
index 94a119a..db4414e 100644
--- a/arch/arm/mach-tegra/common.c
+++ b/arch/arm/mach-tegra/common.c
@@ -25,6 +25,7 @@
#include <linux/reboot.h>
#include <linux/irqchip.h>
#include <linux/clk-provider.h>
+#include <linux/tegra-soc.h>
#include <asm/hardware/cache-l2x0.h>
@@ -109,6 +110,7 @@ void __init tegra_init_early(void)
void __init tegra_init_late(void)
{
+ tegra_cpufreq_init();
tegra_init_suspend();
tegra_cpuidle_init();
tegra_powergate_debugfs_init();
diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm
index 0fa204b..d62902a 100644
--- a/drivers/cpufreq/Kconfig.arm
+++ b/drivers/cpufreq/Kconfig.arm
@@ -229,9 +229,19 @@ config ARM_SPEAR_CPUFREQ
This adds the CPUFreq driver support for SPEAr SOCs.
config ARM_TEGRA_CPUFREQ
- bool "TEGRA CPUFreq support"
- depends on ARCH_TEGRA
+ bool
+ select CPU_FREQ_TABLE
+
+config ARM_EXYNOS_CPUFREQ
+ bool
select CPU_FREQ_TABLE
+
+config ARM_TEGRA20_CPUFREQ
+ bool "NVIDIA TEGRA20"
+ depends on ARCH_TEGRA
default y
+ select ARM_TEGRA_CPUFREQ
help
- This adds the CPUFreq driver support for TEGRA SOCs.
+ This adds the CPUFreq driver for NVIDIA TEGRA20 SoC.
+
+ If in doubt, say N.
diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile
index ad5866c..22a85f0 100644
--- a/drivers/cpufreq/Makefile
+++ b/drivers/cpufreq/Makefile
@@ -77,6 +77,7 @@ obj-$(CONFIG_ARM_SA1100_CPUFREQ) += sa1100-cpufreq.o
obj-$(CONFIG_ARM_SA1110_CPUFREQ) += sa1110-cpufreq.o
obj-$(CONFIG_ARM_SPEAR_CPUFREQ) += spear-cpufreq.o
obj-$(CONFIG_ARM_TEGRA_CPUFREQ) += tegra-cpufreq.o
+obj-$(CONFIG_ARM_TEGRA20_CPUFREQ) += tegra20-cpufreq.o
##################################################################################
# PowerPC platform drivers
diff --git a/drivers/cpufreq/tegra-cpufreq.c b/drivers/cpufreq/tegra-cpufreq.c
index 6eb3dd8..d40428a 100644
--- a/drivers/cpufreq/tegra-cpufreq.c
+++ b/drivers/cpufreq/tegra-cpufreq.c
@@ -23,25 +23,15 @@
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/suspend.h>
+#include <linux/cpu.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
-static struct cpufreq_frequency_table freq_table[] = {
- { .frequency = 216000 },
- { .frequency = 312000 },
- { .frequency = 456000 },
- { .frequency = 608000 },
- { .frequency = 760000 },
- { .frequency = 816000 },
- { .frequency = 912000 },
- { .frequency = 1000000 },
- { .frequency = CPUFREQ_TABLE_END },
-};
+#include "tegra-cpufreq.h"
-#define NUM_CPUS 2
+#define NUM_CPUS 4
-static struct clk *cpu_clk;
-static struct clk *pll_x_clk;
-static struct clk *pll_p_clk;
-static struct clk *emc_clk;
+static struct tegra_cpufreq_data *tegra_data;
static unsigned long target_cpu_speed[NUM_CPUS];
static DEFINE_MUTEX(tegra_cpu_lock);
@@ -49,53 +39,17 @@ static bool is_suspended;
static int tegra_verify_speed(struct cpufreq_policy *policy)
{
- return cpufreq_frequency_table_verify(policy, freq_table);
+ return cpufreq_frequency_table_verify(policy, tegra_data->freq_table);
}
static unsigned int tegra_getspeed(unsigned int cpu)
{
unsigned long rate;
- rate = clk_get_rate(cpu_clk) / 1000;
+ rate = clk_get_rate(tegra_data->cpu_clk) / 1000;
return rate;
}
-static int tegra_cpu_clk_set_rate(unsigned long rate)
-{
- int ret;
-
- /*
- * Take an extra reference to the main pll so it doesn't turn
- * off when we move the cpu off of it
- */
- clk_prepare_enable(pll_x_clk);
-
- ret = clk_set_parent(cpu_clk, pll_p_clk);
- if (ret) {
- pr_err("Failed to switch cpu to clock pll_p\n");
- goto out;
- }
-
- if (rate == clk_get_rate(pll_p_clk))
- goto out;
-
- ret = clk_set_rate(pll_x_clk, rate);
- if (ret) {
- pr_err("Failed to change pll_x to %lu\n", rate);
- goto out;
- }
-
- ret = clk_set_parent(cpu_clk, pll_x_clk);
- if (ret) {
- pr_err("Failed to switch cpu to clock pll_x\n");
- goto out;
- }
-
-out:
- clk_disable_unprepare(pll_x_clk);
- return ret;
-}
-
static int tegra_update_cpu_speed(struct cpufreq_policy *policy,
unsigned long rate)
{
@@ -112,12 +66,8 @@ static int tegra_update_cpu_speed(struct cpufreq_policy *policy,
* Vote on memory bus frequency based on cpu frequency
* This sets the minimum frequency, display or avp may request higher
*/
- if (rate >= 816000)
- clk_set_rate(emc_clk, 600000000); /* cpu 816 MHz, emc max */
- else if (rate >= 456000)
- clk_set_rate(emc_clk, 300000000); /* cpu 456 MHz, emc 150Mhz */
- else
- clk_set_rate(emc_clk, 100000000); /* emc 50Mhz */
+ if (tegra_data->vote_emc_on_cpu_rate)
+ tegra_data->vote_emc_on_cpu_rate(rate);
cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
@@ -126,7 +76,7 @@ static int tegra_update_cpu_speed(struct cpufreq_policy *policy,
freqs.old, freqs.new);
#endif
- ret = tegra_cpu_clk_set_rate(freqs.new * 1000);
+ ret = tegra_data->cpu_clk_set_rate(freqs.new * 1000);
if (ret) {
pr_err("cpu-tegra: Failed to set cpu frequency to %d kHz\n",
freqs.new);
@@ -152,6 +102,7 @@ static int tegra_target(struct cpufreq_policy *policy,
unsigned int target_freq,
unsigned int relation)
{
+ struct cpufreq_frequency_table *freq_table = tegra_data->freq_table;
unsigned int idx;
unsigned int freq;
int ret = 0;
@@ -163,8 +114,8 @@ static int tegra_target(struct cpufreq_policy *policy,
goto out;
}
- cpufreq_frequency_table_target(policy, freq_table, target_freq,
- relation, &idx);
+ cpufreq_frequency_table_target(policy, freq_table,
+ target_freq, relation, &idx);
freq = freq_table[idx].frequency;
@@ -180,6 +131,8 @@ out:
static int tegra_pm_notify(struct notifier_block *nb, unsigned long event,
void *dummy)
{
+ struct cpufreq_frequency_table *freq_table = tegra_data->freq_table;
+
mutex_lock(&tegra_cpu_lock);
if (event == PM_SUSPEND_PREPARE) {
struct cpufreq_policy *policy = cpufreq_cpu_get(0);
@@ -202,11 +155,11 @@ static struct notifier_block tegra_cpu_pm_notifier = {
static int tegra_cpu_init(struct cpufreq_policy *policy)
{
- clk_prepare_enable(emc_clk);
- clk_prepare_enable(cpu_clk);
+ if (tegra_data->cpufreq_clk_init)
+ tegra_data->cpufreq_clk_init();
- cpufreq_frequency_table_cpuinfo(policy, freq_table);
- cpufreq_frequency_table_get_attr(freq_table, policy->cpu);
+ cpufreq_frequency_table_cpuinfo(policy, tegra_data->freq_table);
+ cpufreq_frequency_table_get_attr(tegra_data->freq_table, policy->cpu);
policy->cur = tegra_getspeed(policy->cpu);
target_cpu_speed[policy->cpu] = policy->cur;
@@ -223,8 +176,9 @@ static int tegra_cpu_init(struct cpufreq_policy *policy)
static int tegra_cpu_exit(struct cpufreq_policy *policy)
{
- cpufreq_frequency_table_cpuinfo(policy, freq_table);
- clk_disable_unprepare(emc_clk);
+ cpufreq_frequency_table_cpuinfo(policy, tegra_data->freq_table);
+ if (tegra_data->cpufreq_clk_exit)
+ tegra_data->cpufreq_clk_exit();
return 0;
}
@@ -243,39 +197,77 @@ static struct cpufreq_driver tegra_cpufreq_driver = {
.attr = tegra_cpufreq_attr,
};
-static int __init tegra_cpufreq_init(void)
+static struct {
+ char *compat;
+ int (*init)(struct tegra_cpufreq_data *);
+} tegra_init_funcs[] = {
+ { "nvidia,tegra20", tegra20_cpufreq_init },
+};
+
+static int tegra_cpufreq_probe(struct platform_device *pdev)
{
- cpu_clk = clk_get_sys(NULL, "cclk");
- if (IS_ERR(cpu_clk))
- return PTR_ERR(cpu_clk);
-
- pll_x_clk = clk_get_sys(NULL, "pll_x");
- if (IS_ERR(pll_x_clk))
- return PTR_ERR(pll_x_clk);
-
- pll_p_clk = clk_get_sys(NULL, "pll_p");
- if (IS_ERR(pll_p_clk))
- return PTR_ERR(pll_p_clk);
-
- emc_clk = clk_get_sys("cpu", "emc");
- if (IS_ERR(emc_clk)) {
- clk_put(cpu_clk);
- return PTR_ERR(emc_clk);
+ int i;
+ int ret = -EINVAL;
+
+ tegra_data = devm_kzalloc(&pdev->dev,
+ sizeof(*tegra_data), GFP_KERNEL);
+ if (!tegra_data) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ tegra_data->dev = &pdev->dev;
+
+ for (i = 0; i < ARRAY_SIZE(tegra_init_funcs); i++) {
+ if (of_machine_is_compatible(tegra_init_funcs[i].compat)) {
+ ret = tegra_init_funcs[i].init(tegra_data);
+ if (!ret)
+ break;
+ else
+ goto out;
+ }
+ }
+ if (i == ARRAY_SIZE(tegra_init_funcs))
+ goto out;
+
+ ret = cpufreq_register_driver(&tegra_cpufreq_driver);
+ if (ret) {
+ dev_err(tegra_data->dev,
+ "%s: failed to register cpufreq driver\n", __func__);
+ goto out;
}
- return cpufreq_register_driver(&tegra_cpufreq_driver);
+ return 0;
+out:
+ return ret;
}
-static void __exit tegra_cpufreq_exit(void)
+static int tegra_cpufreq_remove(struct platform_device *pdev)
{
- cpufreq_unregister_driver(&tegra_cpufreq_driver);
- clk_put(emc_clk);
- clk_put(cpu_clk);
+ cpufreq_unregister_driver(&tegra_cpufreq_driver);
+ return 0;
}
+static struct platform_driver tegra_cpufreq_platdrv = {
+ .driver = {
+ .name = "tegra-cpufreq",
+ .owner = THIS_MODULE,
+ },
+ .probe = tegra_cpufreq_probe,
+ .remove = tegra_cpufreq_remove,
+};
+module_platform_driver(tegra_cpufreq_platdrv);
+
+int __init tegra_cpufreq_init(void)
+{
+ struct platform_device_info devinfo = { .name = "tegra-cpufreq", };
+
+ platform_device_register_full(&devinfo);
+
+ return 0;
+}
+EXPORT_SYMBOL(tegra_cpufreq_init);
MODULE_AUTHOR("Colin Cross <ccross at android.com>");
MODULE_DESCRIPTION("cpufreq driver for Nvidia Tegra2");
MODULE_LICENSE("GPL");
-module_init(tegra_cpufreq_init);
-module_exit(tegra_cpufreq_exit);
diff --git a/drivers/cpufreq/tegra-cpufreq.h b/drivers/cpufreq/tegra-cpufreq.h
new file mode 100644
index 0000000..4de091f
--- /dev/null
+++ b/drivers/cpufreq/tegra-cpufreq.h
@@ -0,0 +1,37 @@
+/*
+ * Copyright (c) 2013, NVIDIA Corporation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __LINUX_TEGRA_CPUFREQ_H
+#define __LINUX_TEGRA_CPUFREQ_H
+
+struct tegra_cpufreq_data {
+ struct device *dev;
+ struct clk *cpu_clk;
+ struct cpufreq_frequency_table *freq_table;
+ void (*vote_emc_on_cpu_rate)(unsigned long);
+ int (*cpu_clk_set_rate)(unsigned long);
+ void (*cpufreq_clk_init)(void);
+ void (*cpufreq_clk_exit)(void);
+};
+
+#ifdef CONFIG_ARM_TEGRA20_CPUFREQ
+int tegra20_cpufreq_init(struct tegra_cpufreq_data *data);
+#else
+static inline int tegra20_cpufreq_init(struct tegra_cpufreq_data *data)
+{ return -EOPNOTSUPP; }
+#endif
+
+#endif /* __LINUX_TEGRA_CPUFREQ_H_ */
diff --git a/drivers/cpufreq/tegra20-cpufreq.c b/drivers/cpufreq/tegra20-cpufreq.c
new file mode 100644
index 0000000..ffc2ba6
--- /dev/null
+++ b/drivers/cpufreq/tegra20-cpufreq.c
@@ -0,0 +1,133 @@
+/*
+ * Copyright (c) 2013, NVIDIA CORPORATION. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/cpufreq.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+#include <linux/suspend.h>
+#include <linux/cpu.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+
+#include "tegra-cpufreq.h"
+
+static struct cpufreq_frequency_table freq_table[] = {
+ { .frequency = 216000 },
+ { .frequency = 312000 },
+ { .frequency = 456000 },
+ { .frequency = 608000 },
+ { .frequency = 760000 },
+ { .frequency = 816000 },
+ { .frequency = 912000 },
+ { .frequency = 1000000 },
+ { .frequency = CPUFREQ_TABLE_END },
+};
+
+static struct clk *cpu_clk;
+static struct clk *pll_x_clk;
+static struct clk *pll_p_clk;
+static struct clk *emc_clk;
+
+static void tegra20_vote_emc_on_cpu_rate(unsigned long rate)
+{
+ if (rate >= 816000)
+ clk_set_rate(emc_clk, 600000000); /* cpu 816 MHz, emc max */
+ else if (rate >= 456000)
+ clk_set_rate(emc_clk, 300000000); /* cpu 456 MHz, emc 150Mhz */
+ else
+ clk_set_rate(emc_clk, 100000000); /* emc 50Mhz */
+}
+
+static int tegra20_cpu_clk_set_rate(unsigned long rate)
+{
+ int ret;
+
+ /*
+ * Take an extra reference to the main pll so it doesn't turn
+ * off when we move the cpu off of it
+ */
+ clk_prepare_enable(pll_x_clk);
+
+ ret = clk_set_parent(cpu_clk, pll_p_clk);
+ if (ret) {
+ pr_err("Failed to switch cpu to clock pll_p\n");
+ goto out;
+ }
+
+ if (rate == clk_get_rate(pll_p_clk))
+ goto out;
+
+ ret = clk_set_rate(pll_x_clk, rate);
+ if (ret) {
+ pr_err("Failed to change pll_x to %lu\n", rate);
+ goto out;
+ }
+
+ ret = clk_set_parent(cpu_clk, pll_x_clk);
+ if (ret) {
+ pr_err("Failed to switch cpu to clock pll_x\n");
+ goto out;
+ }
+
+out:
+ clk_disable_unprepare(pll_x_clk);
+ return ret;
+}
+
+static void tegra20_cpufreq_clk_init(void)
+{
+ clk_prepare_enable(emc_clk);
+ clk_prepare_enable(cpu_clk);
+}
+
+static void tegra20_cpufreq_clk_exit(void)
+{
+ clk_disable_unprepare(cpu_clk);
+ clk_disable_unprepare(emc_clk);
+}
+
+int tegra20_cpufreq_init(struct tegra_cpufreq_data *data)
+{
+ cpu_clk = clk_get_sys(NULL, "cclk");
+ if (IS_ERR(cpu_clk))
+ return PTR_ERR(cpu_clk);
+
+ pll_x_clk = clk_get_sys(NULL, "pll_x");
+ if (IS_ERR(pll_x_clk))
+ return PTR_ERR(pll_x_clk);
+
+ pll_p_clk = clk_get_sys(NULL, "pll_p");
+ if (IS_ERR(pll_p_clk))
+ return PTR_ERR(pll_p_clk);
+
+ emc_clk = clk_get_sys("cpu", "emc");
+ if (IS_ERR(emc_clk)) {
+ clk_put(cpu_clk);
+ return PTR_ERR(emc_clk);
+ }
+
+ data->cpu_clk = cpu_clk;
+ data->freq_table = freq_table;
+ data->vote_emc_on_cpu_rate = tegra20_vote_emc_on_cpu_rate;
+ data->cpu_clk_set_rate = tegra20_cpu_clk_set_rate;
+ data->cpufreq_clk_init = tegra20_cpufreq_clk_init;
+ data->cpufreq_clk_exit = tegra20_cpufreq_clk_exit;
+
+ return 0;
+}
+EXPORT_SYMBOL(tegra20_cpufreq_init);
diff --git a/include/linux/tegra-soc.h b/include/linux/tegra-soc.h
index 95f611d..015b905 100644
--- a/include/linux/tegra-soc.h
+++ b/include/linux/tegra-soc.h
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2012, NVIDIA CORPORATION. All rights reserved.
+ * Copyright (c) 2012,2013, NVIDIA CORPORATION. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
@@ -19,4 +19,13 @@
u32 tegra_read_chipid(void);
+#ifdef CONFIG_ARM_TEGRA_CPUFREQ
+int tegra_cpufreq_init(void);
+#else
+static inline int tegra_cpufreq_init(void)
+{
+ retrun EOPNOTSUPP;
+}
+#endif
+
#endif /* __LINUX_TEGRA_SOC_H_ */
--
1.7.9.5
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