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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Copyright (c) 2010 Samsung Electronics Co., Ltd.4 *		http://www.samsung.com5 *6 * CPU frequency scaling for S5PC110/S5PV2107*/8 9#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt10 11#include <linux/types.h>12#include <linux/kernel.h>13#include <linux/init.h>14#include <linux/err.h>15#include <linux/clk.h>16#include <linux/io.h>17#include <linux/cpufreq.h>18#include <linux/of.h>19#include <linux/of_address.h>20#include <linux/platform_device.h>21#include <linux/reboot.h>22#include <linux/regulator/consumer.h>23 24static void __iomem *clk_base;25static void __iomem *dmc_base[2];26 27#define S5P_CLKREG(x)		(clk_base + (x))28 29#define S5P_APLL_LOCK		S5P_CLKREG(0x00)30#define S5P_APLL_CON		S5P_CLKREG(0x100)31#define S5P_CLK_SRC0		S5P_CLKREG(0x200)32#define S5P_CLK_SRC2		S5P_CLKREG(0x208)33#define S5P_CLK_DIV0		S5P_CLKREG(0x300)34#define S5P_CLK_DIV2		S5P_CLKREG(0x308)35#define S5P_CLK_DIV6		S5P_CLKREG(0x318)36#define S5P_CLKDIV_STAT0	S5P_CLKREG(0x1000)37#define S5P_CLKDIV_STAT1	S5P_CLKREG(0x1004)38#define S5P_CLKMUX_STAT0	S5P_CLKREG(0x1100)39#define S5P_CLKMUX_STAT1	S5P_CLKREG(0x1104)40 41#define S5P_ARM_MCS_CON		S5P_CLKREG(0x6100)42 43/* CLKSRC0 */44#define S5P_CLKSRC0_MUX200_SHIFT	(16)45#define S5P_CLKSRC0_MUX200_MASK		(0x1 << S5P_CLKSRC0_MUX200_SHIFT)46#define S5P_CLKSRC0_MUX166_MASK		(0x1<<20)47#define S5P_CLKSRC0_MUX133_MASK		(0x1<<24)48 49/* CLKSRC2 */50#define S5P_CLKSRC2_G3D_SHIFT           (0)51#define S5P_CLKSRC2_G3D_MASK            (0x3 << S5P_CLKSRC2_G3D_SHIFT)52#define S5P_CLKSRC2_MFC_SHIFT           (4)53#define S5P_CLKSRC2_MFC_MASK            (0x3 << S5P_CLKSRC2_MFC_SHIFT)54 55/* CLKDIV0 */56#define S5P_CLKDIV0_APLL_SHIFT		(0)57#define S5P_CLKDIV0_APLL_MASK		(0x7 << S5P_CLKDIV0_APLL_SHIFT)58#define S5P_CLKDIV0_A2M_SHIFT		(4)59#define S5P_CLKDIV0_A2M_MASK		(0x7 << S5P_CLKDIV0_A2M_SHIFT)60#define S5P_CLKDIV0_HCLK200_SHIFT	(8)61#define S5P_CLKDIV0_HCLK200_MASK	(0x7 << S5P_CLKDIV0_HCLK200_SHIFT)62#define S5P_CLKDIV0_PCLK100_SHIFT	(12)63#define S5P_CLKDIV0_PCLK100_MASK	(0x7 << S5P_CLKDIV0_PCLK100_SHIFT)64#define S5P_CLKDIV0_HCLK166_SHIFT	(16)65#define S5P_CLKDIV0_HCLK166_MASK	(0xF << S5P_CLKDIV0_HCLK166_SHIFT)66#define S5P_CLKDIV0_PCLK83_SHIFT	(20)67#define S5P_CLKDIV0_PCLK83_MASK		(0x7 << S5P_CLKDIV0_PCLK83_SHIFT)68#define S5P_CLKDIV0_HCLK133_SHIFT	(24)69#define S5P_CLKDIV0_HCLK133_MASK	(0xF << S5P_CLKDIV0_HCLK133_SHIFT)70#define S5P_CLKDIV0_PCLK66_SHIFT	(28)71#define S5P_CLKDIV0_PCLK66_MASK		(0x7 << S5P_CLKDIV0_PCLK66_SHIFT)72 73/* CLKDIV2 */74#define S5P_CLKDIV2_G3D_SHIFT           (0)75#define S5P_CLKDIV2_G3D_MASK            (0xF << S5P_CLKDIV2_G3D_SHIFT)76#define S5P_CLKDIV2_MFC_SHIFT           (4)77#define S5P_CLKDIV2_MFC_MASK            (0xF << S5P_CLKDIV2_MFC_SHIFT)78 79/* CLKDIV6 */80#define S5P_CLKDIV6_ONEDRAM_SHIFT       (28)81#define S5P_CLKDIV6_ONEDRAM_MASK        (0xF << S5P_CLKDIV6_ONEDRAM_SHIFT)82 83static struct clk *dmc0_clk;84static struct clk *dmc1_clk;85static DEFINE_MUTEX(set_freq_lock);86 87/* APLL M,P,S values for 1G/800Mhz */88#define APLL_VAL_1000	((1 << 31) | (125 << 16) | (3 << 8) | 1)89#define APLL_VAL_800	((1 << 31) | (100 << 16) | (3 << 8) | 1)90 91/* Use 800MHz when entering sleep mode */92#define SLEEP_FREQ	(800 * 1000)93 94/* Tracks if CPU frequency can be updated anymore */95static bool no_cpufreq_access;96 97/*98 * DRAM configurations to calculate refresh counter for changing99 * frequency of memory.100 */101struct dram_conf {102	unsigned long freq;	/* HZ */103	unsigned long refresh;	/* DRAM refresh counter * 1000 */104};105 106/* DRAM configuration (DMC0 and DMC1) */107static struct dram_conf s5pv210_dram_conf[2];108 109enum perf_level {110	L0, L1, L2, L3, L4,111};112 113enum s5pv210_mem_type {114	LPDDR	= 0x1,115	LPDDR2	= 0x2,116	DDR2	= 0x4,117};118 119enum s5pv210_dmc_port {120	DMC0 = 0,121	DMC1,122};123 124static struct cpufreq_frequency_table s5pv210_freq_table[] = {125	{0, L0, 1000*1000},126	{0, L1, 800*1000},127	{0, L2, 400*1000},128	{0, L3, 200*1000},129	{0, L4, 100*1000},130	{0, 0, CPUFREQ_TABLE_END},131};132 133static struct regulator *arm_regulator;134static struct regulator *int_regulator;135 136struct s5pv210_dvs_conf {137	int arm_volt;	/* uV */138	int int_volt;	/* uV */139};140 141static const int arm_volt_max = 1350000;142static const int int_volt_max = 1250000;143 144static struct s5pv210_dvs_conf dvs_conf[] = {145	[L0] = {146		.arm_volt	= 1250000,147		.int_volt	= 1100000,148	},149	[L1] = {150		.arm_volt	= 1200000,151		.int_volt	= 1100000,152	},153	[L2] = {154		.arm_volt	= 1050000,155		.int_volt	= 1100000,156	},157	[L3] = {158		.arm_volt	= 950000,159		.int_volt	= 1100000,160	},161	[L4] = {162		.arm_volt	= 950000,163		.int_volt	= 1000000,164	},165};166 167static u32 clkdiv_val[5][11] = {168	/*169	 * Clock divider value for following170	 * { APLL, A2M, HCLK_MSYS, PCLK_MSYS,171	 *   HCLK_DSYS, PCLK_DSYS, HCLK_PSYS, PCLK_PSYS,172	 *   ONEDRAM, MFC, G3D }173	 */174 175	/* L0 : [1000/200/100][166/83][133/66][200/200] */176	{0, 4, 4, 1, 3, 1, 4, 1, 3, 0, 0},177 178	/* L1 : [800/200/100][166/83][133/66][200/200] */179	{0, 3, 3, 1, 3, 1, 4, 1, 3, 0, 0},180 181	/* L2 : [400/200/100][166/83][133/66][200/200] */182	{1, 3, 1, 1, 3, 1, 4, 1, 3, 0, 0},183 184	/* L3 : [200/200/100][166/83][133/66][200/200] */185	{3, 3, 1, 1, 3, 1, 4, 1, 3, 0, 0},186 187	/* L4 : [100/100/100][83/83][66/66][100/100] */188	{7, 7, 0, 0, 7, 0, 9, 0, 7, 0, 0},189};190 191/*192 * This function set DRAM refresh counter193 * according to operating frequency of DRAM194 * ch: DMC port number 0 or 1195 * freq: Operating frequency of DRAM(KHz)196 */197static void s5pv210_set_refresh(enum s5pv210_dmc_port ch, unsigned long freq)198{199	unsigned long tmp, tmp1;200	void __iomem *reg = NULL;201 202	if (ch == DMC0) {203		reg = (dmc_base[0] + 0x30);204	} else if (ch == DMC1) {205		reg = (dmc_base[1] + 0x30);206	} else {207		pr_err("Cannot find DMC port\n");208		return;209	}210 211	/* Find current DRAM frequency */212	tmp = s5pv210_dram_conf[ch].freq;213 214	tmp /= freq;215 216	tmp1 = s5pv210_dram_conf[ch].refresh;217 218	tmp1 /= tmp;219 220	writel_relaxed(tmp1, reg);221}222 223static int s5pv210_target(struct cpufreq_policy *policy, unsigned int index)224{225	unsigned long reg;226	unsigned int priv_index;227	unsigned int pll_changing = 0;228	unsigned int bus_speed_changing = 0;229	unsigned int old_freq, new_freq;230	int arm_volt, int_volt;231	int ret = 0;232 233	mutex_lock(&set_freq_lock);234 235	if (no_cpufreq_access) {236		pr_err("Denied access to %s as it is disabled temporarily\n",237		       __func__);238		ret = -EINVAL;239		goto exit;240	}241 242	old_freq = policy->cur;243	new_freq = s5pv210_freq_table[index].frequency;244 245	/* Finding current running level index */246	priv_index = cpufreq_table_find_index_h(policy, old_freq, false);247 248	arm_volt = dvs_conf[index].arm_volt;249	int_volt = dvs_conf[index].int_volt;250 251	if (new_freq > old_freq) {252		ret = regulator_set_voltage(arm_regulator,253				arm_volt, arm_volt_max);254		if (ret)255			goto exit;256 257		ret = regulator_set_voltage(int_regulator,258				int_volt, int_volt_max);259		if (ret)260			goto exit;261	}262 263	/* Check if there need to change PLL */264	if ((index == L0) || (priv_index == L0))265		pll_changing = 1;266 267	/* Check if there need to change System bus clock */268	if ((index == L4) || (priv_index == L4))269		bus_speed_changing = 1;270 271	if (bus_speed_changing) {272		/*273		 * Reconfigure DRAM refresh counter value for minimum274		 * temporary clock while changing divider.275		 * expected clock is 83Mhz : 7.8usec/(1/83Mhz) = 0x287276		 */277		if (pll_changing)278			s5pv210_set_refresh(DMC1, 83000);279		else280			s5pv210_set_refresh(DMC1, 100000);281 282		s5pv210_set_refresh(DMC0, 83000);283	}284 285	/*286	 * APLL should be changed in this level287	 * APLL -> MPLL(for stable transition) -> APLL288	 * Some clock source's clock API are not prepared.289	 * Do not use clock API in below code.290	 */291	if (pll_changing) {292		/*293		 * 1. Temporary Change divider for MFC and G3D294		 * SCLKA2M(200/1=200)->(200/4=50)Mhz295		 */296		reg = readl_relaxed(S5P_CLK_DIV2);297		reg &= ~(S5P_CLKDIV2_G3D_MASK | S5P_CLKDIV2_MFC_MASK);298		reg |= (3 << S5P_CLKDIV2_G3D_SHIFT) |299			(3 << S5P_CLKDIV2_MFC_SHIFT);300		writel_relaxed(reg, S5P_CLK_DIV2);301 302		/* For MFC, G3D dividing */303		do {304			reg = readl_relaxed(S5P_CLKDIV_STAT0);305		} while (reg & ((1 << 16) | (1 << 17)));306 307		/*308		 * 2. Change SCLKA2M(200Mhz)to SCLKMPLL in MFC_MUX, G3D MUX309		 * (200/4=50)->(667/4=166)Mhz310		 */311		reg = readl_relaxed(S5P_CLK_SRC2);312		reg &= ~(S5P_CLKSRC2_G3D_MASK | S5P_CLKSRC2_MFC_MASK);313		reg |= (1 << S5P_CLKSRC2_G3D_SHIFT) |314			(1 << S5P_CLKSRC2_MFC_SHIFT);315		writel_relaxed(reg, S5P_CLK_SRC2);316 317		do {318			reg = readl_relaxed(S5P_CLKMUX_STAT1);319		} while (reg & ((1 << 7) | (1 << 3)));320 321		/*322		 * 3. DMC1 refresh count for 133Mhz if (index == L4) is323		 * true refresh counter is already programmed in upper324		 * code. 0x287@83Mhz325		 */326		if (!bus_speed_changing)327			s5pv210_set_refresh(DMC1, 133000);328 329		/* 4. SCLKAPLL -> SCLKMPLL */330		reg = readl_relaxed(S5P_CLK_SRC0);331		reg &= ~(S5P_CLKSRC0_MUX200_MASK);332		reg |= (0x1 << S5P_CLKSRC0_MUX200_SHIFT);333		writel_relaxed(reg, S5P_CLK_SRC0);334 335		do {336			reg = readl_relaxed(S5P_CLKMUX_STAT0);337		} while (reg & (0x1 << 18));338 339	}340 341	/* Change divider */342	reg = readl_relaxed(S5P_CLK_DIV0);343 344	reg &= ~(S5P_CLKDIV0_APLL_MASK | S5P_CLKDIV0_A2M_MASK |345		S5P_CLKDIV0_HCLK200_MASK | S5P_CLKDIV0_PCLK100_MASK |346		S5P_CLKDIV0_HCLK166_MASK | S5P_CLKDIV0_PCLK83_MASK |347		S5P_CLKDIV0_HCLK133_MASK | S5P_CLKDIV0_PCLK66_MASK);348 349	reg |= ((clkdiv_val[index][0] << S5P_CLKDIV0_APLL_SHIFT) |350		(clkdiv_val[index][1] << S5P_CLKDIV0_A2M_SHIFT) |351		(clkdiv_val[index][2] << S5P_CLKDIV0_HCLK200_SHIFT) |352		(clkdiv_val[index][3] << S5P_CLKDIV0_PCLK100_SHIFT) |353		(clkdiv_val[index][4] << S5P_CLKDIV0_HCLK166_SHIFT) |354		(clkdiv_val[index][5] << S5P_CLKDIV0_PCLK83_SHIFT) |355		(clkdiv_val[index][6] << S5P_CLKDIV0_HCLK133_SHIFT) |356		(clkdiv_val[index][7] << S5P_CLKDIV0_PCLK66_SHIFT));357 358	writel_relaxed(reg, S5P_CLK_DIV0);359 360	do {361		reg = readl_relaxed(S5P_CLKDIV_STAT0);362	} while (reg & 0xff);363 364	/* ARM MCS value changed */365	reg = readl_relaxed(S5P_ARM_MCS_CON);366	reg &= ~0x3;367	if (index >= L3)368		reg |= 0x3;369	else370		reg |= 0x1;371 372	writel_relaxed(reg, S5P_ARM_MCS_CON);373 374	if (pll_changing) {375		/* 5. Set Lock time = 30us*24Mhz = 0x2cf */376		writel_relaxed(0x2cf, S5P_APLL_LOCK);377 378		/*379		 * 6. Turn on APLL380		 * 6-1. Set PMS values381		 * 6-2. Wait until the PLL is locked382		 */383		if (index == L0)384			writel_relaxed(APLL_VAL_1000, S5P_APLL_CON);385		else386			writel_relaxed(APLL_VAL_800, S5P_APLL_CON);387 388		do {389			reg = readl_relaxed(S5P_APLL_CON);390		} while (!(reg & (0x1 << 29)));391 392		/*393		 * 7. Change source clock from SCLKMPLL(667Mhz)394		 * to SCLKA2M(200Mhz) in MFC_MUX and G3D MUX395		 * (667/4=166)->(200/4=50)Mhz396		 */397		reg = readl_relaxed(S5P_CLK_SRC2);398		reg &= ~(S5P_CLKSRC2_G3D_MASK | S5P_CLKSRC2_MFC_MASK);399		reg |= (0 << S5P_CLKSRC2_G3D_SHIFT) |400			(0 << S5P_CLKSRC2_MFC_SHIFT);401		writel_relaxed(reg, S5P_CLK_SRC2);402 403		do {404			reg = readl_relaxed(S5P_CLKMUX_STAT1);405		} while (reg & ((1 << 7) | (1 << 3)));406 407		/*408		 * 8. Change divider for MFC and G3D409		 * (200/4=50)->(200/1=200)Mhz410		 */411		reg = readl_relaxed(S5P_CLK_DIV2);412		reg &= ~(S5P_CLKDIV2_G3D_MASK | S5P_CLKDIV2_MFC_MASK);413		reg |= (clkdiv_val[index][10] << S5P_CLKDIV2_G3D_SHIFT) |414			(clkdiv_val[index][9] << S5P_CLKDIV2_MFC_SHIFT);415		writel_relaxed(reg, S5P_CLK_DIV2);416 417		/* For MFC, G3D dividing */418		do {419			reg = readl_relaxed(S5P_CLKDIV_STAT0);420		} while (reg & ((1 << 16) | (1 << 17)));421 422		/* 9. Change MPLL to APLL in MSYS_MUX */423		reg = readl_relaxed(S5P_CLK_SRC0);424		reg &= ~(S5P_CLKSRC0_MUX200_MASK);425		reg |= (0x0 << S5P_CLKSRC0_MUX200_SHIFT);426		writel_relaxed(reg, S5P_CLK_SRC0);427 428		do {429			reg = readl_relaxed(S5P_CLKMUX_STAT0);430		} while (reg & (0x1 << 18));431 432		/*433		 * 10. DMC1 refresh counter434		 * L4 : DMC1 = 100Mhz 7.8us/(1/100) = 0x30c435		 * Others : DMC1 = 200Mhz 7.8us/(1/200) = 0x618436		 */437		if (!bus_speed_changing)438			s5pv210_set_refresh(DMC1, 200000);439	}440 441	/*442	 * L4 level needs to change memory bus speed, hence ONEDRAM clock443	 * divider and memory refresh parameter should be changed444	 */445	if (bus_speed_changing) {446		reg = readl_relaxed(S5P_CLK_DIV6);447		reg &= ~S5P_CLKDIV6_ONEDRAM_MASK;448		reg |= (clkdiv_val[index][8] << S5P_CLKDIV6_ONEDRAM_SHIFT);449		writel_relaxed(reg, S5P_CLK_DIV6);450 451		do {452			reg = readl_relaxed(S5P_CLKDIV_STAT1);453		} while (reg & (1 << 15));454 455		/* Reconfigure DRAM refresh counter value */456		if (index != L4) {457			/*458			 * DMC0 : 166Mhz459			 * DMC1 : 200Mhz460			 */461			s5pv210_set_refresh(DMC0, 166000);462			s5pv210_set_refresh(DMC1, 200000);463		} else {464			/*465			 * DMC0 : 83Mhz466			 * DMC1 : 100Mhz467			 */468			s5pv210_set_refresh(DMC0, 83000);469			s5pv210_set_refresh(DMC1, 100000);470		}471	}472 473	if (new_freq < old_freq) {474		regulator_set_voltage(int_regulator,475				int_volt, int_volt_max);476 477		regulator_set_voltage(arm_regulator,478				arm_volt, arm_volt_max);479	}480 481	pr_debug("Perf changed[L%d]\n", index);482 483exit:484	mutex_unlock(&set_freq_lock);485	return ret;486}487 488static int check_mem_type(void __iomem *dmc_reg)489{490	unsigned long val;491 492	val = readl_relaxed(dmc_reg + 0x4);493	val = (val & (0xf << 8));494 495	return val >> 8;496}497 498static int s5pv210_cpu_init(struct cpufreq_policy *policy)499{500	unsigned long mem_type;501	int ret;502 503	policy->clk = clk_get(NULL, "armclk");504	if (IS_ERR(policy->clk))505		return PTR_ERR(policy->clk);506 507	dmc0_clk = clk_get(NULL, "sclk_dmc0");508	if (IS_ERR(dmc0_clk)) {509		ret = PTR_ERR(dmc0_clk);510		goto out_dmc0;511	}512 513	dmc1_clk = clk_get(NULL, "hclk_msys");514	if (IS_ERR(dmc1_clk)) {515		ret = PTR_ERR(dmc1_clk);516		goto out_dmc1;517	}518 519	if (policy->cpu != 0) {520		ret = -EINVAL;521		goto out_dmc1;522	}523 524	/*525	 * check_mem_type : This driver only support LPDDR & LPDDR2.526	 * other memory type is not supported.527	 */528	mem_type = check_mem_type(dmc_base[0]);529 530	if ((mem_type != LPDDR) && (mem_type != LPDDR2)) {531		pr_err("CPUFreq doesn't support this memory type\n");532		ret = -EINVAL;533		goto out_dmc1;534	}535 536	/* Find current refresh counter and frequency each DMC */537	s5pv210_dram_conf[0].refresh = (readl_relaxed(dmc_base[0] + 0x30) * 1000);538	s5pv210_dram_conf[0].freq = clk_get_rate(dmc0_clk);539 540	s5pv210_dram_conf[1].refresh = (readl_relaxed(dmc_base[1] + 0x30) * 1000);541	s5pv210_dram_conf[1].freq = clk_get_rate(dmc1_clk);542 543	policy->suspend_freq = SLEEP_FREQ;544	cpufreq_generic_init(policy, s5pv210_freq_table, 40000);545	return 0;546 547out_dmc1:548	clk_put(dmc0_clk);549out_dmc0:550	clk_put(policy->clk);551	return ret;552}553 554static int s5pv210_cpufreq_reboot_notifier_event(struct notifier_block *this,555						 unsigned long event, void *ptr)556{557	int ret;558	struct cpufreq_policy *policy;559 560	policy = cpufreq_cpu_get(0);561	if (!policy) {562		pr_debug("cpufreq: get no policy for cpu0\n");563		return NOTIFY_BAD;564	}565 566	ret = cpufreq_driver_target(policy, SLEEP_FREQ, 0);567	cpufreq_cpu_put(policy);568 569	if (ret < 0)570		return NOTIFY_BAD;571 572	no_cpufreq_access = true;573	return NOTIFY_DONE;574}575 576static struct cpufreq_driver s5pv210_driver = {577	.flags		= CPUFREQ_NEED_INITIAL_FREQ_CHECK,578	.verify		= cpufreq_generic_frequency_table_verify,579	.target_index	= s5pv210_target,580	.get		= cpufreq_generic_get,581	.init		= s5pv210_cpu_init,582	.name		= "s5pv210",583	.suspend	= cpufreq_generic_suspend,584	.resume		= cpufreq_generic_suspend, /* We need to set SLEEP FREQ again */585};586 587static struct notifier_block s5pv210_cpufreq_reboot_notifier = {588	.notifier_call = s5pv210_cpufreq_reboot_notifier_event,589};590 591static int s5pv210_cpufreq_probe(struct platform_device *pdev)592{593	struct device *dev = &pdev->dev;594	struct device_node *np;595	int id, result = 0;596 597	/*598	 * HACK: This is a temporary workaround to get access to clock599	 * and DMC controller registers directly and remove static mappings600	 * and dependencies on platform headers. It is necessary to enable601	 * S5PV210 multi-platform support and will be removed together with602	 * this whole driver as soon as S5PV210 gets migrated to use603	 * cpufreq-dt driver.604	 */605	arm_regulator = regulator_get(NULL, "vddarm");606	if (IS_ERR(arm_regulator))607		return dev_err_probe(dev, PTR_ERR(arm_regulator),608				     "failed to get regulator vddarm\n");609 610	int_regulator = regulator_get(NULL, "vddint");611	if (IS_ERR(int_regulator)) {612		result = dev_err_probe(dev, PTR_ERR(int_regulator),613				       "failed to get regulator vddint\n");614		goto err_int_regulator;615	}616 617	np = of_find_compatible_node(NULL, NULL, "samsung,s5pv210-clock");618	if (!np) {619		dev_err(dev, "failed to find clock controller DT node\n");620		result = -ENODEV;621		goto err_clock;622	}623 624	clk_base = of_iomap(np, 0);625	of_node_put(np);626	if (!clk_base) {627		dev_err(dev, "failed to map clock registers\n");628		result = -EFAULT;629		goto err_clock;630	}631 632	for_each_compatible_node(np, NULL, "samsung,s5pv210-dmc") {633		id = of_alias_get_id(np, "dmc");634		if (id < 0 || id >= ARRAY_SIZE(dmc_base)) {635			dev_err(dev, "failed to get alias of dmc node '%pOFn'\n", np);636			of_node_put(np);637			result = id;638			goto err_clk_base;639		}640 641		dmc_base[id] = of_iomap(np, 0);642		if (!dmc_base[id]) {643			dev_err(dev, "failed to map dmc%d registers\n", id);644			of_node_put(np);645			result = -EFAULT;646			goto err_dmc;647		}648	}649 650	for (id = 0; id < ARRAY_SIZE(dmc_base); ++id) {651		if (!dmc_base[id]) {652			dev_err(dev, "failed to find dmc%d node\n", id);653			result = -ENODEV;654			goto err_dmc;655		}656	}657 658	register_reboot_notifier(&s5pv210_cpufreq_reboot_notifier);659 660	return cpufreq_register_driver(&s5pv210_driver);661 662err_dmc:663	for (id = 0; id < ARRAY_SIZE(dmc_base); ++id)664		if (dmc_base[id]) {665			iounmap(dmc_base[id]);666			dmc_base[id] = NULL;667		}668 669err_clk_base:670	iounmap(clk_base);671 672err_clock:673	regulator_put(int_regulator);674 675err_int_regulator:676	regulator_put(arm_regulator);677 678	return result;679}680 681static struct platform_driver s5pv210_cpufreq_platdrv = {682	.driver = {683		.name	= "s5pv210-cpufreq",684	},685	.probe = s5pv210_cpufreq_probe,686};687builtin_platform_driver(s5pv210_cpufreq_platdrv);688