[PATCH 2/3] cpufreq: exynos: Adding cpufreq driver for exynos5440

amit kachhap amit.kachhap at gmail.com
Thu Feb 7 13:39:12 EST 2013


Hi Inder,

Thanks for the review,
On Wed, Feb 6, 2013 at 9:09 PM, Inderpal Singh
<inderpal.singh at linaro.org> wrote:
> On 7 February 2013 01:09, Amit Daniel Kachhap <amit.daniel at samsung.com> wrote:
>> This patch adds dvfs support for exynos5440 SOC. The nature of exynos5440
>> clock controller is different from previous exynos controllers so not using
>> the common exynos cpufreq framework. Also, the device tree parsing is added
>> to get different parameters like frequency, voltage etc.
>>
>> Signed-off-by: Amit Daniel Kachhap <amit.daniel at samsung.com>
>> ---
>>  .../bindings/cpufreq/cpufreq-exynos5440.txt        |   24 ++
>>  drivers/cpufreq/Kconfig.arm                        |    8 +
>>  drivers/cpufreq/Makefile                           |    1 +
>>  drivers/cpufreq/exynos5440-cpufreq.c               |  448 ++++++++++++++++++++
>>  4 files changed, 481 insertions(+)
>>  create mode 100644 Documentation/devicetree/bindings/cpufreq/cpufreq-exynos5440.txt
>>  create mode 100644 drivers/cpufreq/exynos5440-cpufreq.c
>>
>> diff --git a/Documentation/devicetree/bindings/cpufreq/cpufreq-exynos5440.txt b/Documentation/devicetree/bindings/cpufreq/cpufreq-exynos5440.txt
>> new file mode 100644
>> index 0000000..96cb0ed
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/cpufreq/cpufreq-exynos5440.txt
>> @@ -0,0 +1,24 @@
>> +
>> +Exynos5440 cpufreq driver
>> +-------------------
>> +
>> +Exynos5440 SoC cpufreq driver for CPU frequency scaling.
>> +
>> +Required properties:
>> +- interrupts: Interrupt to know the completion of cpu frequency change.
>> +- cpufreq_tbl: Table of frequencies and voltage CPU could be transitioned into,
>> +       in the decreasing order. Frequency should be in KHZ units and voltage
>> +       should be in microvolts.
>> +
>> +All the required listed above must be defined under node cpufreq.
>> +
>> +Example:
>> +--------
>> +       cpufreq at 160000 {
>> +               compatible = "samsung,exynos5440-cpufreq";
>> +               reg = <0x160000 0x1000>;
>> +               interrupts = <0 57 0>;
>> +               cpufreq_tbl = < 1200000 1025000
>> +                               1000000 975000
>> +                               800000  925000 >;
>> +       };
>> diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm
>> index a0b3661..554756f 100644
>> --- a/drivers/cpufreq/Kconfig.arm
>> +++ b/drivers/cpufreq/Kconfig.arm
>> @@ -77,6 +77,14 @@ config ARM_EXYNOS5250_CPUFREQ
>>           This adds the CPUFreq driver for Samsung EXYNOS5250
>>           SoC.
>>
>> +config ARM_EXYNOS5440_CPUFREQ
>> +       def_bool SOC_EXYNOS5440
>> +       help
>> +         This adds the CPUFreq driver for Samsung EXYNOS5440
>> +         SoC. The nature of exynos5440 clock controller is
>> +         different than previous exynos controllers so not using
>> +         the common exynos framework.
>> +
>>  config ARM_SPEAR_CPUFREQ
>>         bool "SPEAr CPUFreq support"
>>         depends on PLAT_SPEAR
>> diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile
>> index fadc4d4..5159ba4 100644
>> --- a/drivers/cpufreq/Makefile
>> +++ b/drivers/cpufreq/Makefile
>> @@ -50,6 +50,7 @@ obj-$(CONFIG_ARM_EXYNOS_CPUFREQ)      += exynos-cpufreq.o
>>  obj-$(CONFIG_ARM_EXYNOS4210_CPUFREQ)   += exynos4210-cpufreq.o
>>  obj-$(CONFIG_ARM_EXYNOS4X12_CPUFREQ)   += exynos4x12-cpufreq.o
>>  obj-$(CONFIG_ARM_EXYNOS5250_CPUFREQ)   += exynos5250-cpufreq.o
>> +obj-$(CONFIG_ARM_EXYNOS5440_CPUFREQ)   += exynos5440-cpufreq.o
>>  obj-$(CONFIG_ARM_OMAP2PLUS_CPUFREQ)     += omap-cpufreq.o
>>  obj-$(CONFIG_ARM_SPEAR_CPUFREQ)                += spear-cpufreq.o
>>
>> diff --git a/drivers/cpufreq/exynos5440-cpufreq.c b/drivers/cpufreq/exynos5440-cpufreq.c
>> new file mode 100644
>> index 0000000..41d39e2
>> --- /dev/null
>> +++ b/drivers/cpufreq/exynos5440-cpufreq.c
>> @@ -0,0 +1,448 @@
>> +/*
>> + * Copyright (c) 2013 Samsung Electronics Co., Ltd.
>> + *             http://www.samsung.com
>> + *
>> + * Amit Daniel Kachhap <amit.daniel at samsung.com>
>> + *
>> + * EXYNOS5440 - CPU frequency scaling support
>> + *
>> + * 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.
>> +*/
>> +
>> +#include <linux/clk.h>
>> +#include <linux/cpufreq.h>
>> +#include <linux/err.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/io.h>
>> +#include <linux/of_address.h>
>> +#include <linux/of_irq.h>
>> +#include <linux/slab.h>
>> +
>> +/*Register definations*/
>> +#define XMU_DVFS_CTRL          0x0060
>> +#define XMU_PMU_P0_7           0x0064
>> +#define XMU_C0_3_PSTATE        0x0090
>> +#define XMU_P_LIMIT            0x00A0
>> +#define XMU_P_STATUS           0x00A4
>> +#define XMU_PMUEVTEN           0x00D0
>> +#define XMU_PMUIRQEN           0x00D4
>> +#define XMU_PMUIRQ             0x00D8
>> +
>> +/*PMU mask and shift definations*/
>> +#define P_VALUE_MASK           0x7
>> +
>> +#define XMU_DVFS_CTRL_EN_SHIFT 0
>> +
>> +#define P0_7_CPUCLKDEV_SHIFT   21
>> +#define P0_7_CPUCLKDEV_MASK    0x7
>> +#define P0_7_ATBCLKDEV_SHIFT   18
>> +#define P0_7_ATBCLKDEV_MASK    0x7
>> +#define P0_7_CSCLKDEV_SHIFT    15
>> +#define P0_7_CSCLKDEV_MASK     0x7
>> +#define P0_7_CPUEMA_SHIFT      28
>> +#define P0_7_CPUEMA_MASK       0xf
>> +#define P0_7_L2EMA_SHIFT       24
>> +#define P0_7_L2EMA_MASK        0xf
>> +#define P0_7_VDD_SHIFT         8
>> +#define P0_7_VDD_MASK          0x7f
>> +#define P0_7_FREQ_SHIFT                0
>> +#define P0_7_FREQ_MASK         0xff
>> +
>> +#define C0_3_PSTATE_VALID_SHIFT        8
>> +#define C0_3_PSTATE_CURR_SHIFT 4
>> +#define C0_3_PSTATE_NEW_SHIFT  0
>> +
>> +#define PSTATE_CHANGED_EVTEN_SHIFT     0
>> +
>> +#define PSTATE_CHANGED_IRQEN_SHIFT     0
>> +
>> +#define PSTATE_CHANGED_SHIFT           0
>> +
>> +/*some constant values for clock divider calculation*/
>> +#define CPU_DIV_FREQ_MAX       500
>> +#define CPU_DBG_FREQ_MAX       375
>> +#define CPU_ATB_FREQ_MAX       500
>> +
>> +#define PMIC_LOW_VOLT          0x30
>> +#define PMIC_HIGH_VOLT         0x28
>> +
>> +#define CPUEMA_HIGH            0x2
>> +#define CPUEMA_MID             0x4
>> +#define CPUEMA_LOW             0x7
>> +
>> +#define L2EMA_HIGH             0x1
>> +#define L2EMA_MID              0x3
>> +#define L2EMA_LOW              0x4
>> +
>> +#define DIV_TAB_MAX    2
>> +/*frequency unit is 20MHZ*/
>> +#define FREQ_UNIT      20
>> +#define MAX_VOLTAGE    1550000 /*In micro volt*/
>> +#define VOLTAGE_STEP   12500   /*In micro volt*/
>> +
>> +#define DRIVER_NAME            "exynos5440_dvfs"
>> +#define DEF_TRANS_LATENCY      100000
>> +
>> +enum cpufreq_level_index {
>> +       L0, L1, L2, L3, L4,
>> +       L5, L6, L7, L8, L9,
>> +};
>> +#define CPUFREQ_LEVEL_END      (L7 + 1)
>> +
>> +struct exynos_dvfs_data {
>> +       void __iomem *base;
>> +       struct resource *mem;
>> +       int irq;
>> +       struct clk *cpu_clk;
>> +       unsigned int cur_frequency;
>> +       bool dvfs_init;
>> +       struct cpufreq_frequency_table *freq_table;
>> +       struct work_struct irq_work;
>> +};
>> +
>> +static struct exynos_dvfs_data *dvfs_info;
>> +static DEFINE_MUTEX(cpufreq_lock);
>> +static struct cpufreq_freqs freqs;
>> +static struct cpufreq_frequency_table exynos_freq_table[CPUFREQ_LEVEL_END + 1];
>> +static unsigned int exynos_volt_table[CPUFREQ_LEVEL_END + 1];
>> +
>> +static void init_div_table(void)
>> +{
>> +       struct cpufreq_frequency_table *freq_tbl = exynos_freq_table;
>> +       unsigned int *volt_tbl = exynos_volt_table;
>> +       unsigned int tmp, clk_div, ema_div, freq, volt_id;
>> +       int i = 0;
>> +
>> +       for (i = 0; freq_tbl[i].frequency != CPUFREQ_TABLE_END; i++) {
>> +
>> +               freq = freq_tbl[i].frequency / 1000; /*In MHZ*/
>> +               clk_div = ((freq / CPU_DIV_FREQ_MAX) & P0_7_CPUCLKDEV_MASK)
>> +                                       << P0_7_CPUCLKDEV_SHIFT;
>> +               clk_div |= ((freq / CPU_ATB_FREQ_MAX) & P0_7_ATBCLKDEV_MASK)
>> +                                       << P0_7_ATBCLKDEV_SHIFT;
>> +               clk_div |= ((freq / CPU_DBG_FREQ_MAX) & P0_7_CSCLKDEV_MASK)
>> +                                       << P0_7_CSCLKDEV_SHIFT;
>> +
>> +               /*Calculate EMA*/
>> +               volt_id = (MAX_VOLTAGE - volt_tbl[i]) / VOLTAGE_STEP;
>> +               if (volt_id < PMIC_HIGH_VOLT) {
>> +                       ema_div = (CPUEMA_HIGH << P0_7_CPUEMA_SHIFT) |
>> +                               (L2EMA_HIGH << P0_7_L2EMA_SHIFT);
>> +               } else if (volt_id > PMIC_LOW_VOLT) {
>> +                       ema_div = (CPUEMA_LOW << P0_7_CPUEMA_SHIFT) |
>> +                               (L2EMA_LOW << P0_7_L2EMA_SHIFT);
>> +               } else {
>> +                       ema_div = (CPUEMA_MID << P0_7_CPUEMA_SHIFT) |
>> +                               (L2EMA_MID << P0_7_L2EMA_SHIFT);
>> +               }
>> +
>> +               tmp = (clk_div | ema_div | (volt_id << P0_7_VDD_SHIFT)
>> +                       | ((freq / FREQ_UNIT) << P0_7_FREQ_SHIFT));
>> +
>> +               __raw_writel(tmp, dvfs_info->base + XMU_PMU_P0_7 + 4 * i);
>> +       }
>> +}
>> +
>> +void exynos_enable_dvfs(void)
>> +{
>> +       unsigned int tmp, i, cpu;
>> +       struct cpufreq_frequency_table *freq_table = dvfs_info->freq_table;
>> +       /*Disable DVFS*/
>> +       __raw_writel(0, dvfs_info->base + XMU_DVFS_CTRL);
>> +
>> +       /*Enable PSTATE Change Event*/
>> +       tmp = __raw_readl(dvfs_info->base + XMU_PMUEVTEN);
>> +       tmp |= (1 << PSTATE_CHANGED_EVTEN_SHIFT);
>> +        __raw_writel(tmp, dvfs_info->base + XMU_PMUEVTEN);
>> +
>> +       /*Enable PSTATE Change IRQ*/
>> +       tmp = __raw_readl(dvfs_info->base + XMU_PMUIRQEN);
>> +       tmp |= (1 << PSTATE_CHANGED_IRQEN_SHIFT);
>> +        __raw_writel(tmp, dvfs_info->base + XMU_PMUIRQEN);
>> +
>> +       /*Set initial perfromance index*/
>> +       for (i = 0; freq_table[i].frequency != CPUFREQ_TABLE_END; i++)
>> +               if (freq_table[i].frequency == dvfs_info->cur_frequency)
>> +                       break;
>> +
>> +       if (freq_table[i].frequency == CPUFREQ_TABLE_END) {
>> +               pr_crit("Boot up frequency not supported\n");
>> +               if (i) {
>> +                       /*Assign the highest frequency*/
>> +                       i = 0;
>> +                       dvfs_info->cur_frequency = freq_table[i].frequency;
>> +               } else {
>> +                       return;
>> +               }
>> +       }
>> +       pr_info("Setting dvfs initial frequency = %u",
>> +                                               dvfs_info->cur_frequency);
>> +
>> +       for (cpu = 0; cpu < CONFIG_NR_CPUS; cpu++) {
>> +               tmp = __raw_readl(dvfs_info->base + XMU_C0_3_PSTATE + cpu * 4);
>> +               tmp &= ~(P_VALUE_MASK << C0_3_PSTATE_NEW_SHIFT);
>> +               tmp |= (i << C0_3_PSTATE_NEW_SHIFT);
>> +               __raw_writel(tmp, dvfs_info->base + XMU_C0_3_PSTATE + cpu * 4);
>> +       }
>> +
>> +       /*Enable DVFS*/
>> +       __raw_writel(1 << XMU_DVFS_CTRL_EN_SHIFT,
>> +                               dvfs_info->base + XMU_DVFS_CTRL);
>> +}
>> +
>> +static int exynos_verify_speed(struct cpufreq_policy *policy)
>> +{
>> +       return cpufreq_frequency_table_verify(policy,
>> +                                             dvfs_info->freq_table);
>> +}
>> +
>> +static unsigned int exynos_getspeed(unsigned int cpu)
>> +{
>> +       return dvfs_info->cur_frequency;
>> +}
>> +
>> +static int exynos_target(struct cpufreq_policy *policy,
>> +                         unsigned int target_freq,
>> +                         unsigned int relation)
>> +{
>> +       unsigned int index, old_index, tmp;
>> +       int ret = 0, i;
>> +       struct cpufreq_frequency_table *freq_table = dvfs_info->freq_table;
>> +
>> +       mutex_lock(&cpufreq_lock);
>> +
>> +       freqs.old = dvfs_info->cur_frequency;
>> +
>> +       if (dvfs_info->dvfs_init == false) {
>> +               ret = -EAGAIN;
>> +               goto out;
>> +       }
>> +
>> +       /*
>> +        * The policy max have been changed so that we cannot get proper
>> +        * old_index with cpufreq_frequency_table_target(). Thus, ignore
>> +        * policy and get the index from the raw freqeuncy table.
>> +        */
>> +       for (old_index = 0;
>> +               freq_table[old_index].frequency != CPUFREQ_TABLE_END;
>> +               old_index++)
>> +               if (freq_table[old_index].frequency == freqs.old)
>> +                       break;
>> +
>> +       if (freq_table[old_index].frequency == CPUFREQ_TABLE_END) {
>> +               ret = -EINVAL;
>> +               goto out;
>> +       }
>> +
>> +       if (cpufreq_frequency_table_target(policy, freq_table,
>> +                                          target_freq, relation, &index)) {
>> +               ret = -EINVAL;
>> +               goto out;
>> +       }
>> +
>> +       freqs.new = freq_table[index].frequency;
>> +       freqs.cpu = policy->cpu;
>> +
>> +       for_each_cpu(freqs.cpu, policy->cpus)
>> +               cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
>> +
>> +       /*Set the target frequency in all C0_3_PSTATE register*/
>> +       for_each_cpu(i, policy->cpus) {
>> +               tmp = __raw_readl(dvfs_info->base + XMU_C0_3_PSTATE + i * 4);
>> +               tmp &= ~(P_VALUE_MASK << C0_3_PSTATE_NEW_SHIFT);
>> +               tmp |= (index << C0_3_PSTATE_NEW_SHIFT);
>> +
>> +               __raw_writel(tmp, dvfs_info->base + XMU_C0_3_PSTATE + i * 4);
>> +       }
>> +out:
>> +       mutex_unlock(&cpufreq_lock);
>> +       return ret;
>> +}
>> +
>> +static void exynos_cpufreq_work(struct work_struct *work)
>> +{
>> +       unsigned int cur_pstate, index;
>> +       struct cpufreq_policy *policy = cpufreq_cpu_get(0); /* boot CPU */
>> +       struct cpufreq_frequency_table *freq_table = dvfs_info->freq_table;
>> +
>> +       mutex_lock(&cpufreq_lock);
>> +
>> +       freqs.old = dvfs_info->cur_frequency;
>> +
>> +       cur_pstate = __raw_readl(dvfs_info->base + XMU_P_STATUS);
>> +       if (cur_pstate >> C0_3_PSTATE_VALID_SHIFT & 0x1)
>> +               index = (cur_pstate >> C0_3_PSTATE_CURR_SHIFT) & P_VALUE_MASK;
>> +       else
>> +               index = (cur_pstate >> C0_3_PSTATE_NEW_SHIFT) & P_VALUE_MASK;
>> +
>> +       if (index < CPUFREQ_LEVEL_END)
>> +               freqs.new = freq_table[index].frequency;
>> +
>> +       for_each_cpu(freqs.cpu, policy->cpus)
>> +               cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
>> +
>> +       dvfs_info->cur_frequency = freqs.new;
>> +
>> +       cpufreq_cpu_put(policy);
>> +       mutex_unlock(&cpufreq_lock);
>> +       enable_irq(dvfs_info->irq);
>> +}
>> +
>> +static irqreturn_t exynos_cpufreq_irq(int irq, void *id)
>> +{
>> +       unsigned int tmp;
>> +
>> +       tmp = __raw_readl(dvfs_info->base + XMU_PMUIRQ);
>> +       if (tmp >> PSTATE_CHANGED_SHIFT & 0x1) {
>> +               __raw_writel(tmp, dvfs_info->base + XMU_PMUIRQ);
>> +
>> +               if (dvfs_info->dvfs_init == true) {
>> +                       disable_irq_nosync(irq);
>> +                       schedule_work(&dvfs_info->irq_work);
>> +               }
>> +       }
>> +       return IRQ_HANDLED;
>> +}
>> +
>> +static int exynos_cpufreq_cpu_init(struct cpufreq_policy *policy)
>> +{
>> +       policy->cur = policy->min = policy->max = dvfs_info->cur_frequency;
>> +
>> +       cpufreq_frequency_table_get_attr(dvfs_info->freq_table, policy->cpu);
>> +
>> +       /* set the transition latency value */
>> +       policy->cpuinfo.transition_latency = DEF_TRANS_LATENCY;
>
> transition_latency can be provided through DT.
Yes I also thought but all previous exynos cpufreq driver uses the
same constant value so didn't create dt node.
>
>> +
>> +       /*
>> +        * EXYNOS5440 multi-core processors has 4 cores
>> +        * that the frequency cannot be set independently.
>> +        * Each cpu is bound to the same speed.
>> +        * So the affected cpu is all of the cpus.
>> +        */
>> +       if (num_online_cpus() == 1) {
>> +               cpumask_copy(policy->related_cpus, cpu_possible_mask);
>> +               cpumask_copy(policy->cpus, cpu_online_mask);
>> +       } else {
>> +               policy->shared_type = CPUFREQ_SHARED_TYPE_ANY;
>> +               cpumask_setall(policy->cpus);
>> +       }
>> +
>> +       return cpufreq_frequency_table_cpuinfo(policy, dvfs_info->freq_table);
>> +}
>> +
>> +static struct cpufreq_driver exynos_driver = {
>> +       .flags          = CPUFREQ_STICKY,
>> +       .verify         = exynos_verify_speed,
>> +       .target         = exynos_target,
>> +       .get            = exynos_getspeed,
>> +       .init           = exynos_cpufreq_cpu_init,
>> +       .name           = DRIVER_NAME,
>> +};
>> +
>
> Since this driver is only for exynos5440, having the same names as
> common exynos-cpufreq is misleading.
Yes your suggestion is good but the names like exynos5440_* looks very long.
>
>> +static int __init exynos_cpufreq_init(void)
>> +{
>> +       int ret = -EINVAL, len, i;
>> +       struct device_node *np;
>> +       struct cpufreq_frequency_table *freq_tbl = exynos_freq_table;
>> +       unsigned int *volt_tbl = exynos_volt_table;
>> +       const struct property *prop;
>> +       const __be32 *val;
>> +
>> +       np =  of_find_compatible_node(NULL, NULL, "samsung,exynos5440-cpufreq");
>> +       if (!np)
>> +               return -ENODEV;
>> +
>> +       dvfs_info = kzalloc(sizeof(struct exynos_dvfs_data), GFP_KERNEL);
>> +       if (!dvfs_info) {
>> +               of_node_put(np);
>> +               return -ENOMEM;
>> +       }
>> +
>> +       dvfs_info->base = of_iomap(np, 0);
>> +       if (!dvfs_info->base) {
>> +               pr_err("No cpufreq memory map found\n");
>> +               ret = -ENODEV;
>> +               goto err_map;
>> +
>> +       }
>> +
>> +       dvfs_info->irq = irq_of_parse_and_map(np, 0);
>> +
>> +       if (dvfs_info->irq == 0) {
>> +               pr_err("No cpufreq irq found\n");
>> +               ret = -ENODEV;
>> +               goto err_irq_parse;
>> +       }
>> +
>> +       prop = of_find_property(np, "cpufreq_tbl", NULL);
>> +       if (!prop || !prop->value) {
>> +               pr_err("No cpufreq table found\n");
>> +               ret = -ENODEV;
>> +               goto err_irq_parse;
>> +       }
>> +
>> +       len = prop->length / sizeof(u32);
>> +       val = prop->value;
>> +
>> +       if ((len == 0) || (len / 2 > CPUFREQ_LEVEL_END)) {
>> +               pr_err("Invalid cpufreq table\n");
>> +               ret = -ENODEV;
>> +               goto err_irq_parse;
>> +       }
>> +
>> +       for (i = 0; i < (len / 2); i++) {
>> +               freq_tbl[i].index = i;
>> +               freq_tbl[i].frequency = be32_to_cpup(val++);
>> +               volt_tbl[i] = be32_to_cpup(val++);
>> +       }
>> +
>> +       freq_tbl[i].index = i;
>> +       freq_tbl[i].frequency = CPUFREQ_TABLE_END;
>
> How about using OPP library to allocate and setup freqtable ? It will
> clean up this code and you wont have to have a statically allocated
> exynos_freq_table.

Ok I will check for this.

Thanks,
Amit
>
> Thanks,
> Inder
>
>> +
>> +       dvfs_info->freq_table = freq_tbl;
>> +
>> +       dvfs_info->cpu_clk = clk_get(NULL, "armclk");
>> +       if (IS_ERR(dvfs_info->cpu_clk)) {
>> +               pr_err("Failed to get cpu clock\n");
>> +               ret = PTR_ERR(dvfs_info->cpu_clk);
>> +               goto err_irq_parse;
>> +       }
>> +
>> +       INIT_WORK(&dvfs_info->irq_work, exynos_cpufreq_work);
>> +       if (request_irq(dvfs_info->irq, exynos_cpufreq_irq,
>> +                               IRQF_TRIGGER_NONE, DRIVER_NAME, dvfs_info)) {
>> +               pr_err("Failed to register IRQ\n");
>> +               ret = -ENODEV;
>> +               goto err_irq_req;
>> +       }
>> +
>> +       dvfs_info->cur_frequency = clk_get_rate(dvfs_info->cpu_clk) / 1000;
>> +       init_div_table();
>> +       exynos_enable_dvfs();
>> +
>> +       if (cpufreq_register_driver(&exynos_driver)) {
>> +               pr_err("%s: failed to register cpufreq driver\n", __func__);
>> +               goto err_register;
>> +       }
>> +
>> +       of_node_put(np);
>> +       dvfs_info->dvfs_init = true;
>> +       pr_info("exynos5440 DVFS initialised.\n");
>> +
>> +       return 0;
>> +
>> +err_register:
>> +       free_irq(dvfs_info->irq, dvfs_info);
>> +err_irq_req:
>> +       clk_put(dvfs_info->cpu_clk);
>> +err_irq_parse:
>> +       iounmap(dvfs_info->base);
>> +err_map:
>> +       of_node_put(np);
>> +       kfree(dvfs_info);
>> +       pr_err("%s: failed initialization\n", __func__);
>> +       return -EINVAL;
>> +}
>> +late_initcall(exynos_cpufreq_init);
>> --
>> 1.7.10.4
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in
>> the body of a message to majordomo at vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> --
> To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in
> the body of a message to majordomo at vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html



More information about the linux-arm-kernel mailing list