xref: /linux/drivers/cpufreq/s5pv210-cpufreq.c (revision 3932b9ca55b0be314a36d3e84faff3e823c081f5)
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 #include <linux/types.h>
13 #include <linux/kernel.h>
14 #include <linux/init.h>
15 #include <linux/err.h>
16 #include <linux/clk.h>
17 #include <linux/io.h>
18 #include <linux/cpufreq.h>
19 #include <linux/of.h>
20 #include <linux/of_address.h>
21 #include <linux/platform_device.h>
22 #include <linux/reboot.h>
23 #include <linux/regulator/consumer.h>
24 
25 static void __iomem *clk_base;
26 static void __iomem *dmc_base[2];
27 
28 #define S5P_CLKREG(x)		(clk_base + (x))
29 
30 #define S5P_APLL_LOCK		S5P_CLKREG(0x00)
31 #define S5P_APLL_CON		S5P_CLKREG(0x100)
32 #define S5P_CLK_SRC0		S5P_CLKREG(0x200)
33 #define S5P_CLK_SRC2		S5P_CLKREG(0x208)
34 #define S5P_CLK_DIV0		S5P_CLKREG(0x300)
35 #define S5P_CLK_DIV2		S5P_CLKREG(0x308)
36 #define S5P_CLK_DIV6		S5P_CLKREG(0x318)
37 #define S5P_CLKDIV_STAT0	S5P_CLKREG(0x1000)
38 #define S5P_CLKDIV_STAT1	S5P_CLKREG(0x1004)
39 #define S5P_CLKMUX_STAT0	S5P_CLKREG(0x1100)
40 #define S5P_CLKMUX_STAT1	S5P_CLKREG(0x1104)
41 
42 #define S5P_ARM_MCS_CON		S5P_CLKREG(0x6100)
43 
44 /* CLKSRC0 */
45 #define S5P_CLKSRC0_MUX200_SHIFT	(16)
46 #define S5P_CLKSRC0_MUX200_MASK		(0x1 << S5P_CLKSRC0_MUX200_SHIFT)
47 #define S5P_CLKSRC0_MUX166_MASK		(0x1<<20)
48 #define S5P_CLKSRC0_MUX133_MASK		(0x1<<24)
49 
50 /* CLKSRC2 */
51 #define S5P_CLKSRC2_G3D_SHIFT           (0)
52 #define S5P_CLKSRC2_G3D_MASK            (0x3 << S5P_CLKSRC2_G3D_SHIFT)
53 #define S5P_CLKSRC2_MFC_SHIFT           (4)
54 #define S5P_CLKSRC2_MFC_MASK            (0x3 << S5P_CLKSRC2_MFC_SHIFT)
55 
56 /* CLKDIV0 */
57 #define S5P_CLKDIV0_APLL_SHIFT		(0)
58 #define S5P_CLKDIV0_APLL_MASK		(0x7 << S5P_CLKDIV0_APLL_SHIFT)
59 #define S5P_CLKDIV0_A2M_SHIFT		(4)
60 #define S5P_CLKDIV0_A2M_MASK		(0x7 << S5P_CLKDIV0_A2M_SHIFT)
61 #define S5P_CLKDIV0_HCLK200_SHIFT	(8)
62 #define S5P_CLKDIV0_HCLK200_MASK	(0x7 << S5P_CLKDIV0_HCLK200_SHIFT)
63 #define S5P_CLKDIV0_PCLK100_SHIFT	(12)
64 #define S5P_CLKDIV0_PCLK100_MASK	(0x7 << S5P_CLKDIV0_PCLK100_SHIFT)
65 #define S5P_CLKDIV0_HCLK166_SHIFT	(16)
66 #define S5P_CLKDIV0_HCLK166_MASK	(0xF << S5P_CLKDIV0_HCLK166_SHIFT)
67 #define S5P_CLKDIV0_PCLK83_SHIFT	(20)
68 #define S5P_CLKDIV0_PCLK83_MASK		(0x7 << S5P_CLKDIV0_PCLK83_SHIFT)
69 #define S5P_CLKDIV0_HCLK133_SHIFT	(24)
70 #define S5P_CLKDIV0_HCLK133_MASK	(0xF << S5P_CLKDIV0_HCLK133_SHIFT)
71 #define S5P_CLKDIV0_PCLK66_SHIFT	(28)
72 #define S5P_CLKDIV0_PCLK66_MASK		(0x7 << S5P_CLKDIV0_PCLK66_SHIFT)
73 
74 /* CLKDIV2 */
75 #define S5P_CLKDIV2_G3D_SHIFT           (0)
76 #define S5P_CLKDIV2_G3D_MASK            (0xF << S5P_CLKDIV2_G3D_SHIFT)
77 #define S5P_CLKDIV2_MFC_SHIFT           (4)
78 #define S5P_CLKDIV2_MFC_MASK            (0xF << S5P_CLKDIV2_MFC_SHIFT)
79 
80 /* CLKDIV6 */
81 #define S5P_CLKDIV6_ONEDRAM_SHIFT       (28)
82 #define S5P_CLKDIV6_ONEDRAM_MASK        (0xF << S5P_CLKDIV6_ONEDRAM_SHIFT)
83 
84 static struct clk *dmc0_clk;
85 static struct clk *dmc1_clk;
86 static DEFINE_MUTEX(set_freq_lock);
87 
88 /* APLL M,P,S values for 1G/800Mhz */
89 #define APLL_VAL_1000	((1 << 31) | (125 << 16) | (3 << 8) | 1)
90 #define APLL_VAL_800	((1 << 31) | (100 << 16) | (3 << 8) | 1)
91 
92 /* Use 800MHz when entering sleep mode */
93 #define SLEEP_FREQ	(800 * 1000)
94 
95 /* Tracks if cpu freqency can be updated anymore */
96 static bool no_cpufreq_access;
97 
98 /*
99  * DRAM configurations to calculate refresh counter for changing
100  * frequency of memory.
101  */
102 struct dram_conf {
103 	unsigned long freq;	/* HZ */
104 	unsigned long refresh;	/* DRAM refresh counter * 1000 */
105 };
106 
107 /* DRAM configuration (DMC0 and DMC1) */
108 static struct dram_conf s5pv210_dram_conf[2];
109 
110 enum perf_level {
111 	L0, L1, L2, L3, L4,
112 };
113 
114 enum s5pv210_mem_type {
115 	LPDDR	= 0x1,
116 	LPDDR2	= 0x2,
117 	DDR2	= 0x4,
118 };
119 
120 enum s5pv210_dmc_port {
121 	DMC0 = 0,
122 	DMC1,
123 };
124 
125 static struct cpufreq_frequency_table s5pv210_freq_table[] = {
126 	{0, L0, 1000*1000},
127 	{0, L1, 800*1000},
128 	{0, L2, 400*1000},
129 	{0, L3, 200*1000},
130 	{0, L4, 100*1000},
131 	{0, 0, CPUFREQ_TABLE_END},
132 };
133 
134 static struct regulator *arm_regulator;
135 static struct regulator *int_regulator;
136 
137 struct s5pv210_dvs_conf {
138 	int arm_volt;	/* uV */
139 	int int_volt;	/* uV */
140 };
141 
142 static const int arm_volt_max = 1350000;
143 static const int int_volt_max = 1250000;
144 
145 static struct s5pv210_dvs_conf dvs_conf[] = {
146 	[L0] = {
147 		.arm_volt	= 1250000,
148 		.int_volt	= 1100000,
149 	},
150 	[L1] = {
151 		.arm_volt	= 1200000,
152 		.int_volt	= 1100000,
153 	},
154 	[L2] = {
155 		.arm_volt	= 1050000,
156 		.int_volt	= 1100000,
157 	},
158 	[L3] = {
159 		.arm_volt	= 950000,
160 		.int_volt	= 1100000,
161 	},
162 	[L4] = {
163 		.arm_volt	= 950000,
164 		.int_volt	= 1000000,
165 	},
166 };
167 
168 static u32 clkdiv_val[5][11] = {
169 	/*
170 	 * Clock divider value for following
171 	 * { APLL, A2M, HCLK_MSYS, PCLK_MSYS,
172 	 *   HCLK_DSYS, PCLK_DSYS, HCLK_PSYS, PCLK_PSYS,
173 	 *   ONEDRAM, MFC, G3D }
174 	 */
175 
176 	/* L0 : [1000/200/100][166/83][133/66][200/200] */
177 	{0, 4, 4, 1, 3, 1, 4, 1, 3, 0, 0},
178 
179 	/* L1 : [800/200/100][166/83][133/66][200/200] */
180 	{0, 3, 3, 1, 3, 1, 4, 1, 3, 0, 0},
181 
182 	/* L2 : [400/200/100][166/83][133/66][200/200] */
183 	{1, 3, 1, 1, 3, 1, 4, 1, 3, 0, 0},
184 
185 	/* L3 : [200/200/100][166/83][133/66][200/200] */
186 	{3, 3, 1, 1, 3, 1, 4, 1, 3, 0, 0},
187 
188 	/* L4 : [100/100/100][83/83][66/66][100/100] */
189 	{7, 7, 0, 0, 7, 0, 9, 0, 7, 0, 0},
190 };
191 
192 /*
193  * This function set DRAM refresh counter
194  * accoriding to operating frequency of DRAM
195  * ch: DMC port number 0 or 1
196  * freq: Operating frequency of DRAM(KHz)
197  */
198 static void s5pv210_set_refresh(enum s5pv210_dmc_port ch, unsigned long freq)
199 {
200 	unsigned long tmp, tmp1;
201 	void __iomem *reg = NULL;
202 
203 	if (ch == DMC0) {
204 		reg = (dmc_base[0] + 0x30);
205 	} else if (ch == DMC1) {
206 		reg = (dmc_base[1] + 0x30);
207 	} else {
208 		printk(KERN_ERR "Cannot find DMC port\n");
209 		return;
210 	}
211 
212 	/* Find current DRAM frequency */
213 	tmp = s5pv210_dram_conf[ch].freq;
214 
215 	do_div(tmp, freq);
216 
217 	tmp1 = s5pv210_dram_conf[ch].refresh;
218 
219 	do_div(tmp1, tmp);
220 
221 	__raw_writel(tmp1, reg);
222 }
223 
224 static int s5pv210_target(struct cpufreq_policy *policy, unsigned int index)
225 {
226 	unsigned long reg;
227 	unsigned int priv_index;
228 	unsigned int pll_changing = 0;
229 	unsigned int bus_speed_changing = 0;
230 	unsigned int old_freq, new_freq;
231 	int arm_volt, int_volt;
232 	int ret = 0;
233 
234 	mutex_lock(&set_freq_lock);
235 
236 	if (no_cpufreq_access) {
237 		pr_err("Denied access to %s as it is disabled temporarily\n",
238 		       __func__);
239 		ret = -EINVAL;
240 		goto exit;
241 	}
242 
243 	old_freq = policy->cur;
244 	new_freq = s5pv210_freq_table[index].frequency;
245 
246 	/* Finding current running level index */
247 	if (cpufreq_frequency_table_target(policy, s5pv210_freq_table,
248 					   old_freq, CPUFREQ_RELATION_H,
249 					   &priv_index)) {
250 		ret = -EINVAL;
251 		goto exit;
252 	}
253 
254 	arm_volt = dvs_conf[index].arm_volt;
255 	int_volt = dvs_conf[index].int_volt;
256 
257 	if (new_freq > old_freq) {
258 		ret = regulator_set_voltage(arm_regulator,
259 				arm_volt, arm_volt_max);
260 		if (ret)
261 			goto exit;
262 
263 		ret = regulator_set_voltage(int_regulator,
264 				int_volt, int_volt_max);
265 		if (ret)
266 			goto exit;
267 	}
268 
269 	/* Check if there need to change PLL */
270 	if ((index == L0) || (priv_index == L0))
271 		pll_changing = 1;
272 
273 	/* Check if there need to change System bus clock */
274 	if ((index == L4) || (priv_index == L4))
275 		bus_speed_changing = 1;
276 
277 	if (bus_speed_changing) {
278 		/*
279 		 * Reconfigure DRAM refresh counter value for minimum
280 		 * temporary clock while changing divider.
281 		 * expected clock is 83Mhz : 7.8usec/(1/83Mhz) = 0x287
282 		 */
283 		if (pll_changing)
284 			s5pv210_set_refresh(DMC1, 83000);
285 		else
286 			s5pv210_set_refresh(DMC1, 100000);
287 
288 		s5pv210_set_refresh(DMC0, 83000);
289 	}
290 
291 	/*
292 	 * APLL should be changed in this level
293 	 * APLL -> MPLL(for stable transition) -> APLL
294 	 * Some clock source's clock API are not prepared.
295 	 * Do not use clock API in below code.
296 	 */
297 	if (pll_changing) {
298 		/*
299 		 * 1. Temporary Change divider for MFC and G3D
300 		 * SCLKA2M(200/1=200)->(200/4=50)Mhz
301 		 */
302 		reg = __raw_readl(S5P_CLK_DIV2);
303 		reg &= ~(S5P_CLKDIV2_G3D_MASK | S5P_CLKDIV2_MFC_MASK);
304 		reg |= (3 << S5P_CLKDIV2_G3D_SHIFT) |
305 			(3 << S5P_CLKDIV2_MFC_SHIFT);
306 		__raw_writel(reg, S5P_CLK_DIV2);
307 
308 		/* For MFC, G3D dividing */
309 		do {
310 			reg = __raw_readl(S5P_CLKDIV_STAT0);
311 		} while (reg & ((1 << 16) | (1 << 17)));
312 
313 		/*
314 		 * 2. Change SCLKA2M(200Mhz)to SCLKMPLL in MFC_MUX, G3D MUX
315 		 * (200/4=50)->(667/4=166)Mhz
316 		 */
317 		reg = __raw_readl(S5P_CLK_SRC2);
318 		reg &= ~(S5P_CLKSRC2_G3D_MASK | S5P_CLKSRC2_MFC_MASK);
319 		reg |= (1 << S5P_CLKSRC2_G3D_SHIFT) |
320 			(1 << S5P_CLKSRC2_MFC_SHIFT);
321 		__raw_writel(reg, S5P_CLK_SRC2);
322 
323 		do {
324 			reg = __raw_readl(S5P_CLKMUX_STAT1);
325 		} while (reg & ((1 << 7) | (1 << 3)));
326 
327 		/*
328 		 * 3. DMC1 refresh count for 133Mhz if (index == L4) is
329 		 * true refresh counter is already programed in upper
330 		 * code. 0x287@83Mhz
331 		 */
332 		if (!bus_speed_changing)
333 			s5pv210_set_refresh(DMC1, 133000);
334 
335 		/* 4. SCLKAPLL -> SCLKMPLL */
336 		reg = __raw_readl(S5P_CLK_SRC0);
337 		reg &= ~(S5P_CLKSRC0_MUX200_MASK);
338 		reg |= (0x1 << S5P_CLKSRC0_MUX200_SHIFT);
339 		__raw_writel(reg, S5P_CLK_SRC0);
340 
341 		do {
342 			reg = __raw_readl(S5P_CLKMUX_STAT0);
343 		} while (reg & (0x1 << 18));
344 
345 	}
346 
347 	/* Change divider */
348 	reg = __raw_readl(S5P_CLK_DIV0);
349 
350 	reg &= ~(S5P_CLKDIV0_APLL_MASK | S5P_CLKDIV0_A2M_MASK |
351 		S5P_CLKDIV0_HCLK200_MASK | S5P_CLKDIV0_PCLK100_MASK |
352 		S5P_CLKDIV0_HCLK166_MASK | S5P_CLKDIV0_PCLK83_MASK |
353 		S5P_CLKDIV0_HCLK133_MASK | S5P_CLKDIV0_PCLK66_MASK);
354 
355 	reg |= ((clkdiv_val[index][0] << S5P_CLKDIV0_APLL_SHIFT) |
356 		(clkdiv_val[index][1] << S5P_CLKDIV0_A2M_SHIFT) |
357 		(clkdiv_val[index][2] << S5P_CLKDIV0_HCLK200_SHIFT) |
358 		(clkdiv_val[index][3] << S5P_CLKDIV0_PCLK100_SHIFT) |
359 		(clkdiv_val[index][4] << S5P_CLKDIV0_HCLK166_SHIFT) |
360 		(clkdiv_val[index][5] << S5P_CLKDIV0_PCLK83_SHIFT) |
361 		(clkdiv_val[index][6] << S5P_CLKDIV0_HCLK133_SHIFT) |
362 		(clkdiv_val[index][7] << S5P_CLKDIV0_PCLK66_SHIFT));
363 
364 	__raw_writel(reg, S5P_CLK_DIV0);
365 
366 	do {
367 		reg = __raw_readl(S5P_CLKDIV_STAT0);
368 	} while (reg & 0xff);
369 
370 	/* ARM MCS value changed */
371 	reg = __raw_readl(S5P_ARM_MCS_CON);
372 	reg &= ~0x3;
373 	if (index >= L3)
374 		reg |= 0x3;
375 	else
376 		reg |= 0x1;
377 
378 	__raw_writel(reg, S5P_ARM_MCS_CON);
379 
380 	if (pll_changing) {
381 		/* 5. Set Lock time = 30us*24Mhz = 0x2cf */
382 		__raw_writel(0x2cf, S5P_APLL_LOCK);
383 
384 		/*
385 		 * 6. Turn on APLL
386 		 * 6-1. Set PMS values
387 		 * 6-2. Wait untile the PLL is locked
388 		 */
389 		if (index == L0)
390 			__raw_writel(APLL_VAL_1000, S5P_APLL_CON);
391 		else
392 			__raw_writel(APLL_VAL_800, S5P_APLL_CON);
393 
394 		do {
395 			reg = __raw_readl(S5P_APLL_CON);
396 		} while (!(reg & (0x1 << 29)));
397 
398 		/*
399 		 * 7. Change souce clock from SCLKMPLL(667Mhz)
400 		 * to SCLKA2M(200Mhz) in MFC_MUX and G3D MUX
401 		 * (667/4=166)->(200/4=50)Mhz
402 		 */
403 		reg = __raw_readl(S5P_CLK_SRC2);
404 		reg &= ~(S5P_CLKSRC2_G3D_MASK | S5P_CLKSRC2_MFC_MASK);
405 		reg |= (0 << S5P_CLKSRC2_G3D_SHIFT) |
406 			(0 << S5P_CLKSRC2_MFC_SHIFT);
407 		__raw_writel(reg, S5P_CLK_SRC2);
408 
409 		do {
410 			reg = __raw_readl(S5P_CLKMUX_STAT1);
411 		} while (reg & ((1 << 7) | (1 << 3)));
412 
413 		/*
414 		 * 8. Change divider for MFC and G3D
415 		 * (200/4=50)->(200/1=200)Mhz
416 		 */
417 		reg = __raw_readl(S5P_CLK_DIV2);
418 		reg &= ~(S5P_CLKDIV2_G3D_MASK | S5P_CLKDIV2_MFC_MASK);
419 		reg |= (clkdiv_val[index][10] << S5P_CLKDIV2_G3D_SHIFT) |
420 			(clkdiv_val[index][9] << S5P_CLKDIV2_MFC_SHIFT);
421 		__raw_writel(reg, S5P_CLK_DIV2);
422 
423 		/* For MFC, G3D dividing */
424 		do {
425 			reg = __raw_readl(S5P_CLKDIV_STAT0);
426 		} while (reg & ((1 << 16) | (1 << 17)));
427 
428 		/* 9. Change MPLL to APLL in MSYS_MUX */
429 		reg = __raw_readl(S5P_CLK_SRC0);
430 		reg &= ~(S5P_CLKSRC0_MUX200_MASK);
431 		reg |= (0x0 << S5P_CLKSRC0_MUX200_SHIFT);
432 		__raw_writel(reg, S5P_CLK_SRC0);
433 
434 		do {
435 			reg = __raw_readl(S5P_CLKMUX_STAT0);
436 		} while (reg & (0x1 << 18));
437 
438 		/*
439 		 * 10. DMC1 refresh counter
440 		 * L4 : DMC1 = 100Mhz 7.8us/(1/100) = 0x30c
441 		 * Others : DMC1 = 200Mhz 7.8us/(1/200) = 0x618
442 		 */
443 		if (!bus_speed_changing)
444 			s5pv210_set_refresh(DMC1, 200000);
445 	}
446 
447 	/*
448 	 * L4 level need to change memory bus speed, hence onedram clock divier
449 	 * and memory refresh parameter should be changed
450 	 */
451 	if (bus_speed_changing) {
452 		reg = __raw_readl(S5P_CLK_DIV6);
453 		reg &= ~S5P_CLKDIV6_ONEDRAM_MASK;
454 		reg |= (clkdiv_val[index][8] << S5P_CLKDIV6_ONEDRAM_SHIFT);
455 		__raw_writel(reg, S5P_CLK_DIV6);
456 
457 		do {
458 			reg = __raw_readl(S5P_CLKDIV_STAT1);
459 		} while (reg & (1 << 15));
460 
461 		/* Reconfigure DRAM refresh counter value */
462 		if (index != L4) {
463 			/*
464 			 * DMC0 : 166Mhz
465 			 * DMC1 : 200Mhz
466 			 */
467 			s5pv210_set_refresh(DMC0, 166000);
468 			s5pv210_set_refresh(DMC1, 200000);
469 		} else {
470 			/*
471 			 * DMC0 : 83Mhz
472 			 * DMC1 : 100Mhz
473 			 */
474 			s5pv210_set_refresh(DMC0, 83000);
475 			s5pv210_set_refresh(DMC1, 100000);
476 		}
477 	}
478 
479 	if (new_freq < old_freq) {
480 		regulator_set_voltage(int_regulator,
481 				int_volt, int_volt_max);
482 
483 		regulator_set_voltage(arm_regulator,
484 				arm_volt, arm_volt_max);
485 	}
486 
487 	printk(KERN_DEBUG "Perf changed[L%d]\n", index);
488 
489 exit:
490 	mutex_unlock(&set_freq_lock);
491 	return ret;
492 }
493 
494 static int check_mem_type(void __iomem *dmc_reg)
495 {
496 	unsigned long val;
497 
498 	val = __raw_readl(dmc_reg + 0x4);
499 	val = (val & (0xf << 8));
500 
501 	return val >> 8;
502 }
503 
504 static int s5pv210_cpu_init(struct cpufreq_policy *policy)
505 {
506 	unsigned long mem_type;
507 	int ret;
508 
509 	policy->clk = clk_get(NULL, "armclk");
510 	if (IS_ERR(policy->clk))
511 		return PTR_ERR(policy->clk);
512 
513 	dmc0_clk = clk_get(NULL, "sclk_dmc0");
514 	if (IS_ERR(dmc0_clk)) {
515 		ret = PTR_ERR(dmc0_clk);
516 		goto out_dmc0;
517 	}
518 
519 	dmc1_clk = clk_get(NULL, "hclk_msys");
520 	if (IS_ERR(dmc1_clk)) {
521 		ret = PTR_ERR(dmc1_clk);
522 		goto out_dmc1;
523 	}
524 
525 	if (policy->cpu != 0) {
526 		ret = -EINVAL;
527 		goto out_dmc1;
528 	}
529 
530 	/*
531 	 * check_mem_type : This driver only support LPDDR & LPDDR2.
532 	 * other memory type is not supported.
533 	 */
534 	mem_type = check_mem_type(dmc_base[0]);
535 
536 	if ((mem_type != LPDDR) && (mem_type != LPDDR2)) {
537 		printk(KERN_ERR "CPUFreq doesn't support this memory type\n");
538 		ret = -EINVAL;
539 		goto out_dmc1;
540 	}
541 
542 	/* Find current refresh counter and frequency each DMC */
543 	s5pv210_dram_conf[0].refresh = (__raw_readl(dmc_base[0] + 0x30) * 1000);
544 	s5pv210_dram_conf[0].freq = clk_get_rate(dmc0_clk);
545 
546 	s5pv210_dram_conf[1].refresh = (__raw_readl(dmc_base[1] + 0x30) * 1000);
547 	s5pv210_dram_conf[1].freq = clk_get_rate(dmc1_clk);
548 
549 	policy->suspend_freq = SLEEP_FREQ;
550 	return cpufreq_generic_init(policy, s5pv210_freq_table, 40000);
551 
552 out_dmc1:
553 	clk_put(dmc0_clk);
554 out_dmc0:
555 	clk_put(policy->clk);
556 	return ret;
557 }
558 
559 static int s5pv210_cpufreq_reboot_notifier_event(struct notifier_block *this,
560 						 unsigned long event, void *ptr)
561 {
562 	int ret;
563 
564 	ret = cpufreq_driver_target(cpufreq_cpu_get(0), SLEEP_FREQ, 0);
565 	if (ret < 0)
566 		return NOTIFY_BAD;
567 
568 	no_cpufreq_access = true;
569 	return NOTIFY_DONE;
570 }
571 
572 static struct cpufreq_driver s5pv210_driver = {
573 	.flags		= CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK,
574 	.verify		= cpufreq_generic_frequency_table_verify,
575 	.target_index	= s5pv210_target,
576 	.get		= cpufreq_generic_get,
577 	.init		= s5pv210_cpu_init,
578 	.name		= "s5pv210",
579 #ifdef CONFIG_PM
580 	.suspend	= cpufreq_generic_suspend,
581 	.resume		= cpufreq_generic_suspend, /* We need to set SLEEP FREQ again */
582 #endif
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-cpu0 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");
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");
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 		.owner	= THIS_MODULE,
660 	},
661 	.probe = s5pv210_cpufreq_probe,
662 };
663 module_platform_driver(s5pv210_cpufreq_platdrv);
664