xref: /linux/drivers/cpufreq/s5pv210-cpufreq.c (revision 0883c2c06fb5bcf5b9e008270827e63c09a88c1e)
1 /*
2  * Copyright (c) 2010 Samsung Electronics Co., Ltd.
3  *		http://www.samsung.com
4  *
5  * CPU frequency scaling for S5PC110/S5PV210
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10 */
11 
12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13 
14 #include <linux/types.h>
15 #include <linux/kernel.h>
16 #include <linux/init.h>
17 #include <linux/err.h>
18 #include <linux/clk.h>
19 #include <linux/io.h>
20 #include <linux/cpufreq.h>
21 #include <linux/of.h>
22 #include <linux/of_address.h>
23 #include <linux/platform_device.h>
24 #include <linux/reboot.h>
25 #include <linux/regulator/consumer.h>
26 
27 static void __iomem *clk_base;
28 static void __iomem *dmc_base[2];
29 
30 #define S5P_CLKREG(x)		(clk_base + (x))
31 
32 #define S5P_APLL_LOCK		S5P_CLKREG(0x00)
33 #define S5P_APLL_CON		S5P_CLKREG(0x100)
34 #define S5P_CLK_SRC0		S5P_CLKREG(0x200)
35 #define S5P_CLK_SRC2		S5P_CLKREG(0x208)
36 #define S5P_CLK_DIV0		S5P_CLKREG(0x300)
37 #define S5P_CLK_DIV2		S5P_CLKREG(0x308)
38 #define S5P_CLK_DIV6		S5P_CLKREG(0x318)
39 #define S5P_CLKDIV_STAT0	S5P_CLKREG(0x1000)
40 #define S5P_CLKDIV_STAT1	S5P_CLKREG(0x1004)
41 #define S5P_CLKMUX_STAT0	S5P_CLKREG(0x1100)
42 #define S5P_CLKMUX_STAT1	S5P_CLKREG(0x1104)
43 
44 #define S5P_ARM_MCS_CON		S5P_CLKREG(0x6100)
45 
46 /* CLKSRC0 */
47 #define S5P_CLKSRC0_MUX200_SHIFT	(16)
48 #define S5P_CLKSRC0_MUX200_MASK		(0x1 << S5P_CLKSRC0_MUX200_SHIFT)
49 #define S5P_CLKSRC0_MUX166_MASK		(0x1<<20)
50 #define S5P_CLKSRC0_MUX133_MASK		(0x1<<24)
51 
52 /* CLKSRC2 */
53 #define S5P_CLKSRC2_G3D_SHIFT           (0)
54 #define S5P_CLKSRC2_G3D_MASK            (0x3 << S5P_CLKSRC2_G3D_SHIFT)
55 #define S5P_CLKSRC2_MFC_SHIFT           (4)
56 #define S5P_CLKSRC2_MFC_MASK            (0x3 << S5P_CLKSRC2_MFC_SHIFT)
57 
58 /* CLKDIV0 */
59 #define S5P_CLKDIV0_APLL_SHIFT		(0)
60 #define S5P_CLKDIV0_APLL_MASK		(0x7 << S5P_CLKDIV0_APLL_SHIFT)
61 #define S5P_CLKDIV0_A2M_SHIFT		(4)
62 #define S5P_CLKDIV0_A2M_MASK		(0x7 << S5P_CLKDIV0_A2M_SHIFT)
63 #define S5P_CLKDIV0_HCLK200_SHIFT	(8)
64 #define S5P_CLKDIV0_HCLK200_MASK	(0x7 << S5P_CLKDIV0_HCLK200_SHIFT)
65 #define S5P_CLKDIV0_PCLK100_SHIFT	(12)
66 #define S5P_CLKDIV0_PCLK100_MASK	(0x7 << S5P_CLKDIV0_PCLK100_SHIFT)
67 #define S5P_CLKDIV0_HCLK166_SHIFT	(16)
68 #define S5P_CLKDIV0_HCLK166_MASK	(0xF << S5P_CLKDIV0_HCLK166_SHIFT)
69 #define S5P_CLKDIV0_PCLK83_SHIFT	(20)
70 #define S5P_CLKDIV0_PCLK83_MASK		(0x7 << S5P_CLKDIV0_PCLK83_SHIFT)
71 #define S5P_CLKDIV0_HCLK133_SHIFT	(24)
72 #define S5P_CLKDIV0_HCLK133_MASK	(0xF << S5P_CLKDIV0_HCLK133_SHIFT)
73 #define S5P_CLKDIV0_PCLK66_SHIFT	(28)
74 #define S5P_CLKDIV0_PCLK66_MASK		(0x7 << S5P_CLKDIV0_PCLK66_SHIFT)
75 
76 /* CLKDIV2 */
77 #define S5P_CLKDIV2_G3D_SHIFT           (0)
78 #define S5P_CLKDIV2_G3D_MASK            (0xF << S5P_CLKDIV2_G3D_SHIFT)
79 #define S5P_CLKDIV2_MFC_SHIFT           (4)
80 #define S5P_CLKDIV2_MFC_MASK            (0xF << S5P_CLKDIV2_MFC_SHIFT)
81 
82 /* CLKDIV6 */
83 #define S5P_CLKDIV6_ONEDRAM_SHIFT       (28)
84 #define S5P_CLKDIV6_ONEDRAM_MASK        (0xF << S5P_CLKDIV6_ONEDRAM_SHIFT)
85 
86 static struct clk *dmc0_clk;
87 static struct clk *dmc1_clk;
88 static DEFINE_MUTEX(set_freq_lock);
89 
90 /* APLL M,P,S values for 1G/800Mhz */
91 #define APLL_VAL_1000	((1 << 31) | (125 << 16) | (3 << 8) | 1)
92 #define APLL_VAL_800	((1 << 31) | (100 << 16) | (3 << 8) | 1)
93 
94 /* Use 800MHz when entering sleep mode */
95 #define SLEEP_FREQ	(800 * 1000)
96 
97 /* Tracks if cpu freqency can be updated anymore */
98 static bool no_cpufreq_access;
99 
100 /*
101  * DRAM configurations to calculate refresh counter for changing
102  * frequency of memory.
103  */
104 struct dram_conf {
105 	unsigned long freq;	/* HZ */
106 	unsigned long refresh;	/* DRAM refresh counter * 1000 */
107 };
108 
109 /* DRAM configuration (DMC0 and DMC1) */
110 static struct dram_conf s5pv210_dram_conf[2];
111 
112 enum perf_level {
113 	L0, L1, L2, L3, L4,
114 };
115 
116 enum s5pv210_mem_type {
117 	LPDDR	= 0x1,
118 	LPDDR2	= 0x2,
119 	DDR2	= 0x4,
120 };
121 
122 enum s5pv210_dmc_port {
123 	DMC0 = 0,
124 	DMC1,
125 };
126 
127 static struct cpufreq_frequency_table s5pv210_freq_table[] = {
128 	{0, L0, 1000*1000},
129 	{0, L1, 800*1000},
130 	{0, L2, 400*1000},
131 	{0, L3, 200*1000},
132 	{0, L4, 100*1000},
133 	{0, 0, CPUFREQ_TABLE_END},
134 };
135 
136 static struct regulator *arm_regulator;
137 static struct regulator *int_regulator;
138 
139 struct s5pv210_dvs_conf {
140 	int arm_volt;	/* uV */
141 	int int_volt;	/* uV */
142 };
143 
144 static const int arm_volt_max = 1350000;
145 static const int int_volt_max = 1250000;
146 
147 static struct s5pv210_dvs_conf dvs_conf[] = {
148 	[L0] = {
149 		.arm_volt	= 1250000,
150 		.int_volt	= 1100000,
151 	},
152 	[L1] = {
153 		.arm_volt	= 1200000,
154 		.int_volt	= 1100000,
155 	},
156 	[L2] = {
157 		.arm_volt	= 1050000,
158 		.int_volt	= 1100000,
159 	},
160 	[L3] = {
161 		.arm_volt	= 950000,
162 		.int_volt	= 1100000,
163 	},
164 	[L4] = {
165 		.arm_volt	= 950000,
166 		.int_volt	= 1000000,
167 	},
168 };
169 
170 static u32 clkdiv_val[5][11] = {
171 	/*
172 	 * Clock divider value for following
173 	 * { APLL, A2M, HCLK_MSYS, PCLK_MSYS,
174 	 *   HCLK_DSYS, PCLK_DSYS, HCLK_PSYS, PCLK_PSYS,
175 	 *   ONEDRAM, MFC, G3D }
176 	 */
177 
178 	/* L0 : [1000/200/100][166/83][133/66][200/200] */
179 	{0, 4, 4, 1, 3, 1, 4, 1, 3, 0, 0},
180 
181 	/* L1 : [800/200/100][166/83][133/66][200/200] */
182 	{0, 3, 3, 1, 3, 1, 4, 1, 3, 0, 0},
183 
184 	/* L2 : [400/200/100][166/83][133/66][200/200] */
185 	{1, 3, 1, 1, 3, 1, 4, 1, 3, 0, 0},
186 
187 	/* L3 : [200/200/100][166/83][133/66][200/200] */
188 	{3, 3, 1, 1, 3, 1, 4, 1, 3, 0, 0},
189 
190 	/* L4 : [100/100/100][83/83][66/66][100/100] */
191 	{7, 7, 0, 0, 7, 0, 9, 0, 7, 0, 0},
192 };
193 
194 /*
195  * This function set DRAM refresh counter
196  * accoriding to operating frequency of DRAM
197  * ch: DMC port number 0 or 1
198  * freq: Operating frequency of DRAM(KHz)
199  */
200 static void s5pv210_set_refresh(enum s5pv210_dmc_port ch, unsigned long freq)
201 {
202 	unsigned long tmp, tmp1;
203 	void __iomem *reg = NULL;
204 
205 	if (ch == DMC0) {
206 		reg = (dmc_base[0] + 0x30);
207 	} else if (ch == DMC1) {
208 		reg = (dmc_base[1] + 0x30);
209 	} else {
210 		pr_err("Cannot find DMC port\n");
211 		return;
212 	}
213 
214 	/* Find current DRAM frequency */
215 	tmp = s5pv210_dram_conf[ch].freq;
216 
217 	tmp /= freq;
218 
219 	tmp1 = s5pv210_dram_conf[ch].refresh;
220 
221 	tmp1 /= tmp;
222 
223 	__raw_writel(tmp1, reg);
224 }
225 
226 static int s5pv210_target(struct cpufreq_policy *policy, unsigned int index)
227 {
228 	unsigned long reg;
229 	unsigned int priv_index;
230 	unsigned int pll_changing = 0;
231 	unsigned int bus_speed_changing = 0;
232 	unsigned int old_freq, new_freq;
233 	int arm_volt, int_volt;
234 	int ret = 0;
235 
236 	mutex_lock(&set_freq_lock);
237 
238 	if (no_cpufreq_access) {
239 		pr_err("Denied access to %s as it is disabled temporarily\n",
240 		       __func__);
241 		ret = -EINVAL;
242 		goto exit;
243 	}
244 
245 	old_freq = policy->cur;
246 	new_freq = s5pv210_freq_table[index].frequency;
247 
248 	/* Finding current running level index */
249 	if (cpufreq_frequency_table_target(policy, s5pv210_freq_table,
250 					   old_freq, CPUFREQ_RELATION_H,
251 					   &priv_index)) {
252 		ret = -EINVAL;
253 		goto exit;
254 	}
255 
256 	arm_volt = dvs_conf[index].arm_volt;
257 	int_volt = dvs_conf[index].int_volt;
258 
259 	if (new_freq > old_freq) {
260 		ret = regulator_set_voltage(arm_regulator,
261 				arm_volt, arm_volt_max);
262 		if (ret)
263 			goto exit;
264 
265 		ret = regulator_set_voltage(int_regulator,
266 				int_volt, int_volt_max);
267 		if (ret)
268 			goto exit;
269 	}
270 
271 	/* Check if there need to change PLL */
272 	if ((index == L0) || (priv_index == L0))
273 		pll_changing = 1;
274 
275 	/* Check if there need to change System bus clock */
276 	if ((index == L4) || (priv_index == L4))
277 		bus_speed_changing = 1;
278 
279 	if (bus_speed_changing) {
280 		/*
281 		 * Reconfigure DRAM refresh counter value for minimum
282 		 * temporary clock while changing divider.
283 		 * expected clock is 83Mhz : 7.8usec/(1/83Mhz) = 0x287
284 		 */
285 		if (pll_changing)
286 			s5pv210_set_refresh(DMC1, 83000);
287 		else
288 			s5pv210_set_refresh(DMC1, 100000);
289 
290 		s5pv210_set_refresh(DMC0, 83000);
291 	}
292 
293 	/*
294 	 * APLL should be changed in this level
295 	 * APLL -> MPLL(for stable transition) -> APLL
296 	 * Some clock source's clock API are not prepared.
297 	 * Do not use clock API in below code.
298 	 */
299 	if (pll_changing) {
300 		/*
301 		 * 1. Temporary Change divider for MFC and G3D
302 		 * SCLKA2M(200/1=200)->(200/4=50)Mhz
303 		 */
304 		reg = __raw_readl(S5P_CLK_DIV2);
305 		reg &= ~(S5P_CLKDIV2_G3D_MASK | S5P_CLKDIV2_MFC_MASK);
306 		reg |= (3 << S5P_CLKDIV2_G3D_SHIFT) |
307 			(3 << S5P_CLKDIV2_MFC_SHIFT);
308 		__raw_writel(reg, S5P_CLK_DIV2);
309 
310 		/* For MFC, G3D dividing */
311 		do {
312 			reg = __raw_readl(S5P_CLKDIV_STAT0);
313 		} while (reg & ((1 << 16) | (1 << 17)));
314 
315 		/*
316 		 * 2. Change SCLKA2M(200Mhz)to SCLKMPLL in MFC_MUX, G3D MUX
317 		 * (200/4=50)->(667/4=166)Mhz
318 		 */
319 		reg = __raw_readl(S5P_CLK_SRC2);
320 		reg &= ~(S5P_CLKSRC2_G3D_MASK | S5P_CLKSRC2_MFC_MASK);
321 		reg |= (1 << S5P_CLKSRC2_G3D_SHIFT) |
322 			(1 << S5P_CLKSRC2_MFC_SHIFT);
323 		__raw_writel(reg, S5P_CLK_SRC2);
324 
325 		do {
326 			reg = __raw_readl(S5P_CLKMUX_STAT1);
327 		} while (reg & ((1 << 7) | (1 << 3)));
328 
329 		/*
330 		 * 3. DMC1 refresh count for 133Mhz if (index == L4) is
331 		 * true refresh counter is already programed in upper
332 		 * code. 0x287@83Mhz
333 		 */
334 		if (!bus_speed_changing)
335 			s5pv210_set_refresh(DMC1, 133000);
336 
337 		/* 4. SCLKAPLL -> SCLKMPLL */
338 		reg = __raw_readl(S5P_CLK_SRC0);
339 		reg &= ~(S5P_CLKSRC0_MUX200_MASK);
340 		reg |= (0x1 << S5P_CLKSRC0_MUX200_SHIFT);
341 		__raw_writel(reg, S5P_CLK_SRC0);
342 
343 		do {
344 			reg = __raw_readl(S5P_CLKMUX_STAT0);
345 		} while (reg & (0x1 << 18));
346 
347 	}
348 
349 	/* Change divider */
350 	reg = __raw_readl(S5P_CLK_DIV0);
351 
352 	reg &= ~(S5P_CLKDIV0_APLL_MASK | S5P_CLKDIV0_A2M_MASK |
353 		S5P_CLKDIV0_HCLK200_MASK | S5P_CLKDIV0_PCLK100_MASK |
354 		S5P_CLKDIV0_HCLK166_MASK | S5P_CLKDIV0_PCLK83_MASK |
355 		S5P_CLKDIV0_HCLK133_MASK | S5P_CLKDIV0_PCLK66_MASK);
356 
357 	reg |= ((clkdiv_val[index][0] << S5P_CLKDIV0_APLL_SHIFT) |
358 		(clkdiv_val[index][1] << S5P_CLKDIV0_A2M_SHIFT) |
359 		(clkdiv_val[index][2] << S5P_CLKDIV0_HCLK200_SHIFT) |
360 		(clkdiv_val[index][3] << S5P_CLKDIV0_PCLK100_SHIFT) |
361 		(clkdiv_val[index][4] << S5P_CLKDIV0_HCLK166_SHIFT) |
362 		(clkdiv_val[index][5] << S5P_CLKDIV0_PCLK83_SHIFT) |
363 		(clkdiv_val[index][6] << S5P_CLKDIV0_HCLK133_SHIFT) |
364 		(clkdiv_val[index][7] << S5P_CLKDIV0_PCLK66_SHIFT));
365 
366 	__raw_writel(reg, S5P_CLK_DIV0);
367 
368 	do {
369 		reg = __raw_readl(S5P_CLKDIV_STAT0);
370 	} while (reg & 0xff);
371 
372 	/* ARM MCS value changed */
373 	reg = __raw_readl(S5P_ARM_MCS_CON);
374 	reg &= ~0x3;
375 	if (index >= L3)
376 		reg |= 0x3;
377 	else
378 		reg |= 0x1;
379 
380 	__raw_writel(reg, S5P_ARM_MCS_CON);
381 
382 	if (pll_changing) {
383 		/* 5. Set Lock time = 30us*24Mhz = 0x2cf */
384 		__raw_writel(0x2cf, S5P_APLL_LOCK);
385 
386 		/*
387 		 * 6. Turn on APLL
388 		 * 6-1. Set PMS values
389 		 * 6-2. Wait untile the PLL is locked
390 		 */
391 		if (index == L0)
392 			__raw_writel(APLL_VAL_1000, S5P_APLL_CON);
393 		else
394 			__raw_writel(APLL_VAL_800, S5P_APLL_CON);
395 
396 		do {
397 			reg = __raw_readl(S5P_APLL_CON);
398 		} while (!(reg & (0x1 << 29)));
399 
400 		/*
401 		 * 7. Change souce clock from SCLKMPLL(667Mhz)
402 		 * to SCLKA2M(200Mhz) in MFC_MUX and G3D MUX
403 		 * (667/4=166)->(200/4=50)Mhz
404 		 */
405 		reg = __raw_readl(S5P_CLK_SRC2);
406 		reg &= ~(S5P_CLKSRC2_G3D_MASK | S5P_CLKSRC2_MFC_MASK);
407 		reg |= (0 << S5P_CLKSRC2_G3D_SHIFT) |
408 			(0 << S5P_CLKSRC2_MFC_SHIFT);
409 		__raw_writel(reg, S5P_CLK_SRC2);
410 
411 		do {
412 			reg = __raw_readl(S5P_CLKMUX_STAT1);
413 		} while (reg & ((1 << 7) | (1 << 3)));
414 
415 		/*
416 		 * 8. Change divider for MFC and G3D
417 		 * (200/4=50)->(200/1=200)Mhz
418 		 */
419 		reg = __raw_readl(S5P_CLK_DIV2);
420 		reg &= ~(S5P_CLKDIV2_G3D_MASK | S5P_CLKDIV2_MFC_MASK);
421 		reg |= (clkdiv_val[index][10] << S5P_CLKDIV2_G3D_SHIFT) |
422 			(clkdiv_val[index][9] << S5P_CLKDIV2_MFC_SHIFT);
423 		__raw_writel(reg, S5P_CLK_DIV2);
424 
425 		/* For MFC, G3D dividing */
426 		do {
427 			reg = __raw_readl(S5P_CLKDIV_STAT0);
428 		} while (reg & ((1 << 16) | (1 << 17)));
429 
430 		/* 9. Change MPLL to APLL in MSYS_MUX */
431 		reg = __raw_readl(S5P_CLK_SRC0);
432 		reg &= ~(S5P_CLKSRC0_MUX200_MASK);
433 		reg |= (0x0 << S5P_CLKSRC0_MUX200_SHIFT);
434 		__raw_writel(reg, S5P_CLK_SRC0);
435 
436 		do {
437 			reg = __raw_readl(S5P_CLKMUX_STAT0);
438 		} while (reg & (0x1 << 18));
439 
440 		/*
441 		 * 10. DMC1 refresh counter
442 		 * L4 : DMC1 = 100Mhz 7.8us/(1/100) = 0x30c
443 		 * Others : DMC1 = 200Mhz 7.8us/(1/200) = 0x618
444 		 */
445 		if (!bus_speed_changing)
446 			s5pv210_set_refresh(DMC1, 200000);
447 	}
448 
449 	/*
450 	 * L4 level need to change memory bus speed, hence onedram clock divier
451 	 * and memory refresh parameter should be changed
452 	 */
453 	if (bus_speed_changing) {
454 		reg = __raw_readl(S5P_CLK_DIV6);
455 		reg &= ~S5P_CLKDIV6_ONEDRAM_MASK;
456 		reg |= (clkdiv_val[index][8] << S5P_CLKDIV6_ONEDRAM_SHIFT);
457 		__raw_writel(reg, S5P_CLK_DIV6);
458 
459 		do {
460 			reg = __raw_readl(S5P_CLKDIV_STAT1);
461 		} while (reg & (1 << 15));
462 
463 		/* Reconfigure DRAM refresh counter value */
464 		if (index != L4) {
465 			/*
466 			 * DMC0 : 166Mhz
467 			 * DMC1 : 200Mhz
468 			 */
469 			s5pv210_set_refresh(DMC0, 166000);
470 			s5pv210_set_refresh(DMC1, 200000);
471 		} else {
472 			/*
473 			 * DMC0 : 83Mhz
474 			 * DMC1 : 100Mhz
475 			 */
476 			s5pv210_set_refresh(DMC0, 83000);
477 			s5pv210_set_refresh(DMC1, 100000);
478 		}
479 	}
480 
481 	if (new_freq < old_freq) {
482 		regulator_set_voltage(int_regulator,
483 				int_volt, int_volt_max);
484 
485 		regulator_set_voltage(arm_regulator,
486 				arm_volt, arm_volt_max);
487 	}
488 
489 	printk(KERN_DEBUG "Perf changed[L%d]\n", index);
490 
491 exit:
492 	mutex_unlock(&set_freq_lock);
493 	return ret;
494 }
495 
496 static int check_mem_type(void __iomem *dmc_reg)
497 {
498 	unsigned long val;
499 
500 	val = __raw_readl(dmc_reg + 0x4);
501 	val = (val & (0xf << 8));
502 
503 	return val >> 8;
504 }
505 
506 static int s5pv210_cpu_init(struct cpufreq_policy *policy)
507 {
508 	unsigned long mem_type;
509 	int ret;
510 
511 	policy->clk = clk_get(NULL, "armclk");
512 	if (IS_ERR(policy->clk))
513 		return PTR_ERR(policy->clk);
514 
515 	dmc0_clk = clk_get(NULL, "sclk_dmc0");
516 	if (IS_ERR(dmc0_clk)) {
517 		ret = PTR_ERR(dmc0_clk);
518 		goto out_dmc0;
519 	}
520 
521 	dmc1_clk = clk_get(NULL, "hclk_msys");
522 	if (IS_ERR(dmc1_clk)) {
523 		ret = PTR_ERR(dmc1_clk);
524 		goto out_dmc1;
525 	}
526 
527 	if (policy->cpu != 0) {
528 		ret = -EINVAL;
529 		goto out_dmc1;
530 	}
531 
532 	/*
533 	 * check_mem_type : This driver only support LPDDR & LPDDR2.
534 	 * other memory type is not supported.
535 	 */
536 	mem_type = check_mem_type(dmc_base[0]);
537 
538 	if ((mem_type != LPDDR) && (mem_type != LPDDR2)) {
539 		pr_err("CPUFreq doesn't support this memory type\n");
540 		ret = -EINVAL;
541 		goto out_dmc1;
542 	}
543 
544 	/* Find current refresh counter and frequency each DMC */
545 	s5pv210_dram_conf[0].refresh = (__raw_readl(dmc_base[0] + 0x30) * 1000);
546 	s5pv210_dram_conf[0].freq = clk_get_rate(dmc0_clk);
547 
548 	s5pv210_dram_conf[1].refresh = (__raw_readl(dmc_base[1] + 0x30) * 1000);
549 	s5pv210_dram_conf[1].freq = clk_get_rate(dmc1_clk);
550 
551 	policy->suspend_freq = SLEEP_FREQ;
552 	return cpufreq_generic_init(policy, s5pv210_freq_table, 40000);
553 
554 out_dmc1:
555 	clk_put(dmc0_clk);
556 out_dmc0:
557 	clk_put(policy->clk);
558 	return ret;
559 }
560 
561 static int s5pv210_cpufreq_reboot_notifier_event(struct notifier_block *this,
562 						 unsigned long event, void *ptr)
563 {
564 	int ret;
565 
566 	ret = cpufreq_driver_target(cpufreq_cpu_get(0), SLEEP_FREQ, 0);
567 	if (ret < 0)
568 		return NOTIFY_BAD;
569 
570 	no_cpufreq_access = true;
571 	return NOTIFY_DONE;
572 }
573 
574 static struct cpufreq_driver s5pv210_driver = {
575 	.flags		= CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK,
576 	.verify		= cpufreq_generic_frequency_table_verify,
577 	.target_index	= s5pv210_target,
578 	.get		= cpufreq_generic_get,
579 	.init		= s5pv210_cpu_init,
580 	.name		= "s5pv210",
581 	.suspend	= cpufreq_generic_suspend,
582 	.resume		= cpufreq_generic_suspend, /* We need to set SLEEP FREQ again */
583 };
584 
585 static struct notifier_block s5pv210_cpufreq_reboot_notifier = {
586 	.notifier_call = s5pv210_cpufreq_reboot_notifier_event,
587 };
588 
589 static int s5pv210_cpufreq_probe(struct platform_device *pdev)
590 {
591 	struct device_node *np;
592 	int id;
593 
594 	/*
595 	 * HACK: This is a temporary workaround to get access to clock
596 	 * and DMC controller registers directly and remove static mappings
597 	 * and dependencies on platform headers. It is necessary to enable
598 	 * S5PV210 multi-platform support and will be removed together with
599 	 * this whole driver as soon as S5PV210 gets migrated to use
600 	 * cpufreq-dt driver.
601 	 */
602 	np = of_find_compatible_node(NULL, NULL, "samsung,s5pv210-clock");
603 	if (!np) {
604 		pr_err("%s: failed to find clock controller DT node\n",
605 			__func__);
606 		return -ENODEV;
607 	}
608 
609 	clk_base = of_iomap(np, 0);
610 	if (!clk_base) {
611 		pr_err("%s: failed to map clock registers\n", __func__);
612 		return -EFAULT;
613 	}
614 
615 	for_each_compatible_node(np, NULL, "samsung,s5pv210-dmc") {
616 		id = of_alias_get_id(np, "dmc");
617 		if (id < 0 || id >= ARRAY_SIZE(dmc_base)) {
618 			pr_err("%s: failed to get alias of dmc node '%s'\n",
619 				__func__, np->name);
620 			return id;
621 		}
622 
623 		dmc_base[id] = of_iomap(np, 0);
624 		if (!dmc_base[id]) {
625 			pr_err("%s: failed to map dmc%d registers\n",
626 				__func__, id);
627 			return -EFAULT;
628 		}
629 	}
630 
631 	for (id = 0; id < ARRAY_SIZE(dmc_base); ++id) {
632 		if (!dmc_base[id]) {
633 			pr_err("%s: failed to find dmc%d node\n", __func__, id);
634 			return -ENODEV;
635 		}
636 	}
637 
638 	arm_regulator = regulator_get(NULL, "vddarm");
639 	if (IS_ERR(arm_regulator)) {
640 		pr_err("failed to get regulator vddarm\n");
641 		return PTR_ERR(arm_regulator);
642 	}
643 
644 	int_regulator = regulator_get(NULL, "vddint");
645 	if (IS_ERR(int_regulator)) {
646 		pr_err("failed to get regulator vddint\n");
647 		regulator_put(arm_regulator);
648 		return PTR_ERR(int_regulator);
649 	}
650 
651 	register_reboot_notifier(&s5pv210_cpufreq_reboot_notifier);
652 
653 	return cpufreq_register_driver(&s5pv210_driver);
654 }
655 
656 static struct platform_driver s5pv210_cpufreq_platdrv = {
657 	.driver = {
658 		.name	= "s5pv210-cpufreq",
659 	},
660 	.probe = s5pv210_cpufreq_probe,
661 };
662 builtin_platform_driver(s5pv210_cpufreq_platdrv);
663