alistair23-linux/drivers/cpufreq/s5pv210-cpufreq.c
chenqiwu 8ead819f1b cpufreq: s3c: fix unbalances of cpufreq policy refcount
The cpufreq_reboot_notifier_evt() call cpufreq_cpu_get() to get the
cpufreq policy of cpu0, meanwhile, it also increments the kobject
reference count to mark it busy. However, a corresponding call of
cpufreq_cpu_put() is ignored to decrement the kobject reference count
back, which may lead to a potential stuck risk that the cpuhp thread
deadly waits for dropping of kobject refcount when cpufreq policy free.

With this patch, the cpuhp thread can be easily exercised by attempting
to force an unbind of the CPUfreq driver.

Signed-off-by: chenqiwu <chenqiwu@xiaomi.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-01-07 13:31:01 +05:30

697 lines
17 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2010 Samsung Electronics Co., Ltd.
* http://www.samsung.com
*
* CPU frequency scaling for S5PC110/S5PV210
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/cpufreq.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/reboot.h>
#include <linux/regulator/consumer.h>
static void __iomem *clk_base;
static void __iomem *dmc_base[2];
#define S5P_CLKREG(x) (clk_base + (x))
#define S5P_APLL_LOCK S5P_CLKREG(0x00)
#define S5P_APLL_CON S5P_CLKREG(0x100)
#define S5P_CLK_SRC0 S5P_CLKREG(0x200)
#define S5P_CLK_SRC2 S5P_CLKREG(0x208)
#define S5P_CLK_DIV0 S5P_CLKREG(0x300)
#define S5P_CLK_DIV2 S5P_CLKREG(0x308)
#define S5P_CLK_DIV6 S5P_CLKREG(0x318)
#define S5P_CLKDIV_STAT0 S5P_CLKREG(0x1000)
#define S5P_CLKDIV_STAT1 S5P_CLKREG(0x1004)
#define S5P_CLKMUX_STAT0 S5P_CLKREG(0x1100)
#define S5P_CLKMUX_STAT1 S5P_CLKREG(0x1104)
#define S5P_ARM_MCS_CON S5P_CLKREG(0x6100)
/* CLKSRC0 */
#define S5P_CLKSRC0_MUX200_SHIFT (16)
#define S5P_CLKSRC0_MUX200_MASK (0x1 << S5P_CLKSRC0_MUX200_SHIFT)
#define S5P_CLKSRC0_MUX166_MASK (0x1<<20)
#define S5P_CLKSRC0_MUX133_MASK (0x1<<24)
/* CLKSRC2 */
#define S5P_CLKSRC2_G3D_SHIFT (0)
#define S5P_CLKSRC2_G3D_MASK (0x3 << S5P_CLKSRC2_G3D_SHIFT)
#define S5P_CLKSRC2_MFC_SHIFT (4)
#define S5P_CLKSRC2_MFC_MASK (0x3 << S5P_CLKSRC2_MFC_SHIFT)
/* CLKDIV0 */
#define S5P_CLKDIV0_APLL_SHIFT (0)
#define S5P_CLKDIV0_APLL_MASK (0x7 << S5P_CLKDIV0_APLL_SHIFT)
#define S5P_CLKDIV0_A2M_SHIFT (4)
#define S5P_CLKDIV0_A2M_MASK (0x7 << S5P_CLKDIV0_A2M_SHIFT)
#define S5P_CLKDIV0_HCLK200_SHIFT (8)
#define S5P_CLKDIV0_HCLK200_MASK (0x7 << S5P_CLKDIV0_HCLK200_SHIFT)
#define S5P_CLKDIV0_PCLK100_SHIFT (12)
#define S5P_CLKDIV0_PCLK100_MASK (0x7 << S5P_CLKDIV0_PCLK100_SHIFT)
#define S5P_CLKDIV0_HCLK166_SHIFT (16)
#define S5P_CLKDIV0_HCLK166_MASK (0xF << S5P_CLKDIV0_HCLK166_SHIFT)
#define S5P_CLKDIV0_PCLK83_SHIFT (20)
#define S5P_CLKDIV0_PCLK83_MASK (0x7 << S5P_CLKDIV0_PCLK83_SHIFT)
#define S5P_CLKDIV0_HCLK133_SHIFT (24)
#define S5P_CLKDIV0_HCLK133_MASK (0xF << S5P_CLKDIV0_HCLK133_SHIFT)
#define S5P_CLKDIV0_PCLK66_SHIFT (28)
#define S5P_CLKDIV0_PCLK66_MASK (0x7 << S5P_CLKDIV0_PCLK66_SHIFT)
/* CLKDIV2 */
#define S5P_CLKDIV2_G3D_SHIFT (0)
#define S5P_CLKDIV2_G3D_MASK (0xF << S5P_CLKDIV2_G3D_SHIFT)
#define S5P_CLKDIV2_MFC_SHIFT (4)
#define S5P_CLKDIV2_MFC_MASK (0xF << S5P_CLKDIV2_MFC_SHIFT)
/* CLKDIV6 */
#define S5P_CLKDIV6_ONEDRAM_SHIFT (28)
#define S5P_CLKDIV6_ONEDRAM_MASK (0xF << S5P_CLKDIV6_ONEDRAM_SHIFT)
static struct clk *dmc0_clk;
static struct clk *dmc1_clk;
static DEFINE_MUTEX(set_freq_lock);
/* APLL M,P,S values for 1G/800Mhz */
#define APLL_VAL_1000 ((1 << 31) | (125 << 16) | (3 << 8) | 1)
#define APLL_VAL_800 ((1 << 31) | (100 << 16) | (3 << 8) | 1)
/* Use 800MHz when entering sleep mode */
#define SLEEP_FREQ (800 * 1000)
/* Tracks if cpu freqency can be updated anymore */
static bool no_cpufreq_access;
/*
* DRAM configurations to calculate refresh counter for changing
* frequency of memory.
*/
struct dram_conf {
unsigned long freq; /* HZ */
unsigned long refresh; /* DRAM refresh counter * 1000 */
};
/* DRAM configuration (DMC0 and DMC1) */
static struct dram_conf s5pv210_dram_conf[2];
enum perf_level {
L0, L1, L2, L3, L4,
};
enum s5pv210_mem_type {
LPDDR = 0x1,
LPDDR2 = 0x2,
DDR2 = 0x4,
};
enum s5pv210_dmc_port {
DMC0 = 0,
DMC1,
};
static struct cpufreq_frequency_table s5pv210_freq_table[] = {
{0, L0, 1000*1000},
{0, L1, 800*1000},
{0, L2, 400*1000},
{0, L3, 200*1000},
{0, L4, 100*1000},
{0, 0, CPUFREQ_TABLE_END},
};
static struct regulator *arm_regulator;
static struct regulator *int_regulator;
struct s5pv210_dvs_conf {
int arm_volt; /* uV */
int int_volt; /* uV */
};
static const int arm_volt_max = 1350000;
static const int int_volt_max = 1250000;
static struct s5pv210_dvs_conf dvs_conf[] = {
[L0] = {
.arm_volt = 1250000,
.int_volt = 1100000,
},
[L1] = {
.arm_volt = 1200000,
.int_volt = 1100000,
},
[L2] = {
.arm_volt = 1050000,
.int_volt = 1100000,
},
[L3] = {
.arm_volt = 950000,
.int_volt = 1100000,
},
[L4] = {
.arm_volt = 950000,
.int_volt = 1000000,
},
};
static u32 clkdiv_val[5][11] = {
/*
* Clock divider value for following
* { APLL, A2M, HCLK_MSYS, PCLK_MSYS,
* HCLK_DSYS, PCLK_DSYS, HCLK_PSYS, PCLK_PSYS,
* ONEDRAM, MFC, G3D }
*/
/* L0 : [1000/200/100][166/83][133/66][200/200] */
{0, 4, 4, 1, 3, 1, 4, 1, 3, 0, 0},
/* L1 : [800/200/100][166/83][133/66][200/200] */
{0, 3, 3, 1, 3, 1, 4, 1, 3, 0, 0},
/* L2 : [400/200/100][166/83][133/66][200/200] */
{1, 3, 1, 1, 3, 1, 4, 1, 3, 0, 0},
/* L3 : [200/200/100][166/83][133/66][200/200] */
{3, 3, 1, 1, 3, 1, 4, 1, 3, 0, 0},
/* L4 : [100/100/100][83/83][66/66][100/100] */
{7, 7, 0, 0, 7, 0, 9, 0, 7, 0, 0},
};
/*
* This function set DRAM refresh counter
* accoriding to operating frequency of DRAM
* ch: DMC port number 0 or 1
* freq: Operating frequency of DRAM(KHz)
*/
static void s5pv210_set_refresh(enum s5pv210_dmc_port ch, unsigned long freq)
{
unsigned long tmp, tmp1;
void __iomem *reg = NULL;
if (ch == DMC0) {
reg = (dmc_base[0] + 0x30);
} else if (ch == DMC1) {
reg = (dmc_base[1] + 0x30);
} else {
pr_err("Cannot find DMC port\n");
return;
}
/* Find current DRAM frequency */
tmp = s5pv210_dram_conf[ch].freq;
tmp /= freq;
tmp1 = s5pv210_dram_conf[ch].refresh;
tmp1 /= tmp;
writel_relaxed(tmp1, reg);
}
static int s5pv210_target(struct cpufreq_policy *policy, unsigned int index)
{
unsigned long reg;
unsigned int priv_index;
unsigned int pll_changing = 0;
unsigned int bus_speed_changing = 0;
unsigned int old_freq, new_freq;
int arm_volt, int_volt;
int ret = 0;
mutex_lock(&set_freq_lock);
if (no_cpufreq_access) {
pr_err("Denied access to %s as it is disabled temporarily\n",
__func__);
ret = -EINVAL;
goto exit;
}
old_freq = policy->cur;
new_freq = s5pv210_freq_table[index].frequency;
/* Finding current running level index */
priv_index = cpufreq_table_find_index_h(policy, old_freq);
arm_volt = dvs_conf[index].arm_volt;
int_volt = dvs_conf[index].int_volt;
if (new_freq > old_freq) {
ret = regulator_set_voltage(arm_regulator,
arm_volt, arm_volt_max);
if (ret)
goto exit;
ret = regulator_set_voltage(int_regulator,
int_volt, int_volt_max);
if (ret)
goto exit;
}
/* Check if there need to change PLL */
if ((index == L0) || (priv_index == L0))
pll_changing = 1;
/* Check if there need to change System bus clock */
if ((index == L4) || (priv_index == L4))
bus_speed_changing = 1;
if (bus_speed_changing) {
/*
* Reconfigure DRAM refresh counter value for minimum
* temporary clock while changing divider.
* expected clock is 83Mhz : 7.8usec/(1/83Mhz) = 0x287
*/
if (pll_changing)
s5pv210_set_refresh(DMC1, 83000);
else
s5pv210_set_refresh(DMC1, 100000);
s5pv210_set_refresh(DMC0, 83000);
}
/*
* APLL should be changed in this level
* APLL -> MPLL(for stable transition) -> APLL
* Some clock source's clock API are not prepared.
* Do not use clock API in below code.
*/
if (pll_changing) {
/*
* 1. Temporary Change divider for MFC and G3D
* SCLKA2M(200/1=200)->(200/4=50)Mhz
*/
reg = readl_relaxed(S5P_CLK_DIV2);
reg &= ~(S5P_CLKDIV2_G3D_MASK | S5P_CLKDIV2_MFC_MASK);
reg |= (3 << S5P_CLKDIV2_G3D_SHIFT) |
(3 << S5P_CLKDIV2_MFC_SHIFT);
writel_relaxed(reg, S5P_CLK_DIV2);
/* For MFC, G3D dividing */
do {
reg = readl_relaxed(S5P_CLKDIV_STAT0);
} while (reg & ((1 << 16) | (1 << 17)));
/*
* 2. Change SCLKA2M(200Mhz)to SCLKMPLL in MFC_MUX, G3D MUX
* (200/4=50)->(667/4=166)Mhz
*/
reg = readl_relaxed(S5P_CLK_SRC2);
reg &= ~(S5P_CLKSRC2_G3D_MASK | S5P_CLKSRC2_MFC_MASK);
reg |= (1 << S5P_CLKSRC2_G3D_SHIFT) |
(1 << S5P_CLKSRC2_MFC_SHIFT);
writel_relaxed(reg, S5P_CLK_SRC2);
do {
reg = readl_relaxed(S5P_CLKMUX_STAT1);
} while (reg & ((1 << 7) | (1 << 3)));
/*
* 3. DMC1 refresh count for 133Mhz if (index == L4) is
* true refresh counter is already programed in upper
* code. 0x287@83Mhz
*/
if (!bus_speed_changing)
s5pv210_set_refresh(DMC1, 133000);
/* 4. SCLKAPLL -> SCLKMPLL */
reg = readl_relaxed(S5P_CLK_SRC0);
reg &= ~(S5P_CLKSRC0_MUX200_MASK);
reg |= (0x1 << S5P_CLKSRC0_MUX200_SHIFT);
writel_relaxed(reg, S5P_CLK_SRC0);
do {
reg = readl_relaxed(S5P_CLKMUX_STAT0);
} while (reg & (0x1 << 18));
}
/* Change divider */
reg = readl_relaxed(S5P_CLK_DIV0);
reg &= ~(S5P_CLKDIV0_APLL_MASK | S5P_CLKDIV0_A2M_MASK |
S5P_CLKDIV0_HCLK200_MASK | S5P_CLKDIV0_PCLK100_MASK |
S5P_CLKDIV0_HCLK166_MASK | S5P_CLKDIV0_PCLK83_MASK |
S5P_CLKDIV0_HCLK133_MASK | S5P_CLKDIV0_PCLK66_MASK);
reg |= ((clkdiv_val[index][0] << S5P_CLKDIV0_APLL_SHIFT) |
(clkdiv_val[index][1] << S5P_CLKDIV0_A2M_SHIFT) |
(clkdiv_val[index][2] << S5P_CLKDIV0_HCLK200_SHIFT) |
(clkdiv_val[index][3] << S5P_CLKDIV0_PCLK100_SHIFT) |
(clkdiv_val[index][4] << S5P_CLKDIV0_HCLK166_SHIFT) |
(clkdiv_val[index][5] << S5P_CLKDIV0_PCLK83_SHIFT) |
(clkdiv_val[index][6] << S5P_CLKDIV0_HCLK133_SHIFT) |
(clkdiv_val[index][7] << S5P_CLKDIV0_PCLK66_SHIFT));
writel_relaxed(reg, S5P_CLK_DIV0);
do {
reg = readl_relaxed(S5P_CLKDIV_STAT0);
} while (reg & 0xff);
/* ARM MCS value changed */
reg = readl_relaxed(S5P_ARM_MCS_CON);
reg &= ~0x3;
if (index >= L3)
reg |= 0x3;
else
reg |= 0x1;
writel_relaxed(reg, S5P_ARM_MCS_CON);
if (pll_changing) {
/* 5. Set Lock time = 30us*24Mhz = 0x2cf */
writel_relaxed(0x2cf, S5P_APLL_LOCK);
/*
* 6. Turn on APLL
* 6-1. Set PMS values
* 6-2. Wait untile the PLL is locked
*/
if (index == L0)
writel_relaxed(APLL_VAL_1000, S5P_APLL_CON);
else
writel_relaxed(APLL_VAL_800, S5P_APLL_CON);
do {
reg = readl_relaxed(S5P_APLL_CON);
} while (!(reg & (0x1 << 29)));
/*
* 7. Change souce clock from SCLKMPLL(667Mhz)
* to SCLKA2M(200Mhz) in MFC_MUX and G3D MUX
* (667/4=166)->(200/4=50)Mhz
*/
reg = readl_relaxed(S5P_CLK_SRC2);
reg &= ~(S5P_CLKSRC2_G3D_MASK | S5P_CLKSRC2_MFC_MASK);
reg |= (0 << S5P_CLKSRC2_G3D_SHIFT) |
(0 << S5P_CLKSRC2_MFC_SHIFT);
writel_relaxed(reg, S5P_CLK_SRC2);
do {
reg = readl_relaxed(S5P_CLKMUX_STAT1);
} while (reg & ((1 << 7) | (1 << 3)));
/*
* 8. Change divider for MFC and G3D
* (200/4=50)->(200/1=200)Mhz
*/
reg = readl_relaxed(S5P_CLK_DIV2);
reg &= ~(S5P_CLKDIV2_G3D_MASK | S5P_CLKDIV2_MFC_MASK);
reg |= (clkdiv_val[index][10] << S5P_CLKDIV2_G3D_SHIFT) |
(clkdiv_val[index][9] << S5P_CLKDIV2_MFC_SHIFT);
writel_relaxed(reg, S5P_CLK_DIV2);
/* For MFC, G3D dividing */
do {
reg = readl_relaxed(S5P_CLKDIV_STAT0);
} while (reg & ((1 << 16) | (1 << 17)));
/* 9. Change MPLL to APLL in MSYS_MUX */
reg = readl_relaxed(S5P_CLK_SRC0);
reg &= ~(S5P_CLKSRC0_MUX200_MASK);
reg |= (0x0 << S5P_CLKSRC0_MUX200_SHIFT);
writel_relaxed(reg, S5P_CLK_SRC0);
do {
reg = readl_relaxed(S5P_CLKMUX_STAT0);
} while (reg & (0x1 << 18));
/*
* 10. DMC1 refresh counter
* L4 : DMC1 = 100Mhz 7.8us/(1/100) = 0x30c
* Others : DMC1 = 200Mhz 7.8us/(1/200) = 0x618
*/
if (!bus_speed_changing)
s5pv210_set_refresh(DMC1, 200000);
}
/*
* L4 level need to change memory bus speed, hence onedram clock divier
* and memory refresh parameter should be changed
*/
if (bus_speed_changing) {
reg = readl_relaxed(S5P_CLK_DIV6);
reg &= ~S5P_CLKDIV6_ONEDRAM_MASK;
reg |= (clkdiv_val[index][8] << S5P_CLKDIV6_ONEDRAM_SHIFT);
writel_relaxed(reg, S5P_CLK_DIV6);
do {
reg = readl_relaxed(S5P_CLKDIV_STAT1);
} while (reg & (1 << 15));
/* Reconfigure DRAM refresh counter value */
if (index != L4) {
/*
* DMC0 : 166Mhz
* DMC1 : 200Mhz
*/
s5pv210_set_refresh(DMC0, 166000);
s5pv210_set_refresh(DMC1, 200000);
} else {
/*
* DMC0 : 83Mhz
* DMC1 : 100Mhz
*/
s5pv210_set_refresh(DMC0, 83000);
s5pv210_set_refresh(DMC1, 100000);
}
}
if (new_freq < old_freq) {
regulator_set_voltage(int_regulator,
int_volt, int_volt_max);
regulator_set_voltage(arm_regulator,
arm_volt, arm_volt_max);
}
pr_debug("Perf changed[L%d]\n", index);
exit:
mutex_unlock(&set_freq_lock);
return ret;
}
static int check_mem_type(void __iomem *dmc_reg)
{
unsigned long val;
val = readl_relaxed(dmc_reg + 0x4);
val = (val & (0xf << 8));
return val >> 8;
}
static int s5pv210_cpu_init(struct cpufreq_policy *policy)
{
unsigned long mem_type;
int ret;
policy->clk = clk_get(NULL, "armclk");
if (IS_ERR(policy->clk))
return PTR_ERR(policy->clk);
dmc0_clk = clk_get(NULL, "sclk_dmc0");
if (IS_ERR(dmc0_clk)) {
ret = PTR_ERR(dmc0_clk);
goto out_dmc0;
}
dmc1_clk = clk_get(NULL, "hclk_msys");
if (IS_ERR(dmc1_clk)) {
ret = PTR_ERR(dmc1_clk);
goto out_dmc1;
}
if (policy->cpu != 0) {
ret = -EINVAL;
goto out_dmc1;
}
/*
* check_mem_type : This driver only support LPDDR & LPDDR2.
* other memory type is not supported.
*/
mem_type = check_mem_type(dmc_base[0]);
if ((mem_type != LPDDR) && (mem_type != LPDDR2)) {
pr_err("CPUFreq doesn't support this memory type\n");
ret = -EINVAL;
goto out_dmc1;
}
/* Find current refresh counter and frequency each DMC */
s5pv210_dram_conf[0].refresh = (readl_relaxed(dmc_base[0] + 0x30) * 1000);
s5pv210_dram_conf[0].freq = clk_get_rate(dmc0_clk);
s5pv210_dram_conf[1].refresh = (readl_relaxed(dmc_base[1] + 0x30) * 1000);
s5pv210_dram_conf[1].freq = clk_get_rate(dmc1_clk);
policy->suspend_freq = SLEEP_FREQ;
cpufreq_generic_init(policy, s5pv210_freq_table, 40000);
return 0;
out_dmc1:
clk_put(dmc0_clk);
out_dmc0:
clk_put(policy->clk);
return ret;
}
static int s5pv210_cpufreq_reboot_notifier_event(struct notifier_block *this,
unsigned long event, void *ptr)
{
int ret;
struct cpufreq_policy *policy;
policy = cpufreq_cpu_get(0);
if (!policy) {
pr_debug("cpufreq: get no policy for cpu0\n");
return NOTIFY_BAD;
}
ret = cpufreq_driver_target(policy, SLEEP_FREQ, 0);
cpufreq_cpu_put(policy);
if (ret < 0)
return NOTIFY_BAD;
no_cpufreq_access = true;
return NOTIFY_DONE;
}
static struct cpufreq_driver s5pv210_driver = {
.flags = CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK,
.verify = cpufreq_generic_frequency_table_verify,
.target_index = s5pv210_target,
.get = cpufreq_generic_get,
.init = s5pv210_cpu_init,
.name = "s5pv210",
.suspend = cpufreq_generic_suspend,
.resume = cpufreq_generic_suspend, /* We need to set SLEEP FREQ again */
};
static struct notifier_block s5pv210_cpufreq_reboot_notifier = {
.notifier_call = s5pv210_cpufreq_reboot_notifier_event,
};
static int s5pv210_cpufreq_probe(struct platform_device *pdev)
{
struct device_node *np;
int id, result = 0;
/*
* HACK: This is a temporary workaround to get access to clock
* and DMC controller registers directly and remove static mappings
* and dependencies on platform headers. It is necessary to enable
* S5PV210 multi-platform support and will be removed together with
* this whole driver as soon as S5PV210 gets migrated to use
* cpufreq-dt driver.
*/
arm_regulator = regulator_get(NULL, "vddarm");
if (IS_ERR(arm_regulator)) {
if (PTR_ERR(arm_regulator) == -EPROBE_DEFER)
pr_debug("vddarm regulator not ready, defer\n");
else
pr_err("failed to get regulator vddarm\n");
return PTR_ERR(arm_regulator);
}
int_regulator = regulator_get(NULL, "vddint");
if (IS_ERR(int_regulator)) {
if (PTR_ERR(int_regulator) == -EPROBE_DEFER)
pr_debug("vddint regulator not ready, defer\n");
else
pr_err("failed to get regulator vddint\n");
result = PTR_ERR(int_regulator);
goto err_int_regulator;
}
np = of_find_compatible_node(NULL, NULL, "samsung,s5pv210-clock");
if (!np) {
pr_err("%s: failed to find clock controller DT node\n",
__func__);
result = -ENODEV;
goto err_clock;
}
clk_base = of_iomap(np, 0);
of_node_put(np);
if (!clk_base) {
pr_err("%s: failed to map clock registers\n", __func__);
result = -EFAULT;
goto err_clock;
}
for_each_compatible_node(np, NULL, "samsung,s5pv210-dmc") {
id = of_alias_get_id(np, "dmc");
if (id < 0 || id >= ARRAY_SIZE(dmc_base)) {
pr_err("%s: failed to get alias of dmc node '%pOFn'\n",
__func__, np);
of_node_put(np);
result = id;
goto err_clk_base;
}
dmc_base[id] = of_iomap(np, 0);
if (!dmc_base[id]) {
pr_err("%s: failed to map dmc%d registers\n",
__func__, id);
of_node_put(np);
result = -EFAULT;
goto err_dmc;
}
}
for (id = 0; id < ARRAY_SIZE(dmc_base); ++id) {
if (!dmc_base[id]) {
pr_err("%s: failed to find dmc%d node\n", __func__, id);
result = -ENODEV;
goto err_dmc;
}
}
register_reboot_notifier(&s5pv210_cpufreq_reboot_notifier);
return cpufreq_register_driver(&s5pv210_driver);
err_dmc:
for (id = 0; id < ARRAY_SIZE(dmc_base); ++id)
if (dmc_base[id]) {
iounmap(dmc_base[id]);
dmc_base[id] = NULL;
}
err_clk_base:
iounmap(clk_base);
err_clock:
regulator_put(int_regulator);
err_int_regulator:
regulator_put(arm_regulator);
return result;
}
static struct platform_driver s5pv210_cpufreq_platdrv = {
.driver = {
.name = "s5pv210-cpufreq",
},
.probe = s5pv210_cpufreq_probe,
};
builtin_platform_driver(s5pv210_cpufreq_platdrv);