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 	writel_relaxed(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 	priv_index = cpufreq_table_find_index_h(policy, old_freq);
250 
251 	arm_volt = dvs_conf[index].arm_volt;
252 	int_volt = dvs_conf[index].int_volt;
253 
254 	if (new_freq > old_freq) {
255 		ret = regulator_set_voltage(arm_regulator,
256 				arm_volt, arm_volt_max);
257 		if (ret)
258 			goto exit;
259 
260 		ret = regulator_set_voltage(int_regulator,
261 				int_volt, int_volt_max);
262 		if (ret)
263 			goto exit;
264 	}
265 
266 	/* Check if there need to change PLL */
267 	if ((index == L0) || (priv_index == L0))
268 		pll_changing = 1;
269 
270 	/* Check if there need to change System bus clock */
271 	if ((index == L4) || (priv_index == L4))
272 		bus_speed_changing = 1;
273 
274 	if (bus_speed_changing) {
275 		/*
276 		 * Reconfigure DRAM refresh counter value for minimum
277 		 * temporary clock while changing divider.
278 		 * expected clock is 83Mhz : 7.8usec/(1/83Mhz) = 0x287
279 		 */
280 		if (pll_changing)
281 			s5pv210_set_refresh(DMC1, 83000);
282 		else
283 			s5pv210_set_refresh(DMC1, 100000);
284 
285 		s5pv210_set_refresh(DMC0, 83000);
286 	}
287 
288 	/*
289 	 * APLL should be changed in this level
290 	 * APLL -> MPLL(for stable transition) -> APLL
291 	 * Some clock source's clock API are not prepared.
292 	 * Do not use clock API in below code.
293 	 */
294 	if (pll_changing) {
295 		/*
296 		 * 1. Temporary Change divider for MFC and G3D
297 		 * SCLKA2M(200/1=200)->(200/4=50)Mhz
298 		 */
299 		reg = readl_relaxed(S5P_CLK_DIV2);
300 		reg &= ~(S5P_CLKDIV2_G3D_MASK | S5P_CLKDIV2_MFC_MASK);
301 		reg |= (3 << S5P_CLKDIV2_G3D_SHIFT) |
302 			(3 << S5P_CLKDIV2_MFC_SHIFT);
303 		writel_relaxed(reg, S5P_CLK_DIV2);
304 
305 		/* For MFC, G3D dividing */
306 		do {
307 			reg = readl_relaxed(S5P_CLKDIV_STAT0);
308 		} while (reg & ((1 << 16) | (1 << 17)));
309 
310 		/*
311 		 * 2. Change SCLKA2M(200Mhz)to SCLKMPLL in MFC_MUX, G3D MUX
312 		 * (200/4=50)->(667/4=166)Mhz
313 		 */
314 		reg = readl_relaxed(S5P_CLK_SRC2);
315 		reg &= ~(S5P_CLKSRC2_G3D_MASK | S5P_CLKSRC2_MFC_MASK);
316 		reg |= (1 << S5P_CLKSRC2_G3D_SHIFT) |
317 			(1 << S5P_CLKSRC2_MFC_SHIFT);
318 		writel_relaxed(reg, S5P_CLK_SRC2);
319 
320 		do {
321 			reg = readl_relaxed(S5P_CLKMUX_STAT1);
322 		} while (reg & ((1 << 7) | (1 << 3)));
323 
324 		/*
325 		 * 3. DMC1 refresh count for 133Mhz if (index == L4) is
326 		 * true refresh counter is already programed in upper
327 		 * code. 0x287@83Mhz
328 		 */
329 		if (!bus_speed_changing)
330 			s5pv210_set_refresh(DMC1, 133000);
331 
332 		/* 4. SCLKAPLL -> SCLKMPLL */
333 		reg = readl_relaxed(S5P_CLK_SRC0);
334 		reg &= ~(S5P_CLKSRC0_MUX200_MASK);
335 		reg |= (0x1 << S5P_CLKSRC0_MUX200_SHIFT);
336 		writel_relaxed(reg, S5P_CLK_SRC0);
337 
338 		do {
339 			reg = readl_relaxed(S5P_CLKMUX_STAT0);
340 		} while (reg & (0x1 << 18));
341 
342 	}
343 
344 	/* Change divider */
345 	reg = readl_relaxed(S5P_CLK_DIV0);
346 
347 	reg &= ~(S5P_CLKDIV0_APLL_MASK | S5P_CLKDIV0_A2M_MASK |
348 		S5P_CLKDIV0_HCLK200_MASK | S5P_CLKDIV0_PCLK100_MASK |
349 		S5P_CLKDIV0_HCLK166_MASK | S5P_CLKDIV0_PCLK83_MASK |
350 		S5P_CLKDIV0_HCLK133_MASK | S5P_CLKDIV0_PCLK66_MASK);
351 
352 	reg |= ((clkdiv_val[index][0] << S5P_CLKDIV0_APLL_SHIFT) |
353 		(clkdiv_val[index][1] << S5P_CLKDIV0_A2M_SHIFT) |
354 		(clkdiv_val[index][2] << S5P_CLKDIV0_HCLK200_SHIFT) |
355 		(clkdiv_val[index][3] << S5P_CLKDIV0_PCLK100_SHIFT) |
356 		(clkdiv_val[index][4] << S5P_CLKDIV0_HCLK166_SHIFT) |
357 		(clkdiv_val[index][5] << S5P_CLKDIV0_PCLK83_SHIFT) |
358 		(clkdiv_val[index][6] << S5P_CLKDIV0_HCLK133_SHIFT) |
359 		(clkdiv_val[index][7] << S5P_CLKDIV0_PCLK66_SHIFT));
360 
361 	writel_relaxed(reg, S5P_CLK_DIV0);
362 
363 	do {
364 		reg = readl_relaxed(S5P_CLKDIV_STAT0);
365 	} while (reg & 0xff);
366 
367 	/* ARM MCS value changed */
368 	reg = readl_relaxed(S5P_ARM_MCS_CON);
369 	reg &= ~0x3;
370 	if (index >= L3)
371 		reg |= 0x3;
372 	else
373 		reg |= 0x1;
374 
375 	writel_relaxed(reg, S5P_ARM_MCS_CON);
376 
377 	if (pll_changing) {
378 		/* 5. Set Lock time = 30us*24Mhz = 0x2cf */
379 		writel_relaxed(0x2cf, S5P_APLL_LOCK);
380 
381 		/*
382 		 * 6. Turn on APLL
383 		 * 6-1. Set PMS values
384 		 * 6-2. Wait untile the PLL is locked
385 		 */
386 		if (index == L0)
387 			writel_relaxed(APLL_VAL_1000, S5P_APLL_CON);
388 		else
389 			writel_relaxed(APLL_VAL_800, S5P_APLL_CON);
390 
391 		do {
392 			reg = readl_relaxed(S5P_APLL_CON);
393 		} while (!(reg & (0x1 << 29)));
394 
395 		/*
396 		 * 7. Change souce clock from SCLKMPLL(667Mhz)
397 		 * to SCLKA2M(200Mhz) in MFC_MUX and G3D MUX
398 		 * (667/4=166)->(200/4=50)Mhz
399 		 */
400 		reg = readl_relaxed(S5P_CLK_SRC2);
401 		reg &= ~(S5P_CLKSRC2_G3D_MASK | S5P_CLKSRC2_MFC_MASK);
402 		reg |= (0 << S5P_CLKSRC2_G3D_SHIFT) |
403 			(0 << S5P_CLKSRC2_MFC_SHIFT);
404 		writel_relaxed(reg, S5P_CLK_SRC2);
405 
406 		do {
407 			reg = readl_relaxed(S5P_CLKMUX_STAT1);
408 		} while (reg & ((1 << 7) | (1 << 3)));
409 
410 		/*
411 		 * 8. Change divider for MFC and G3D
412 		 * (200/4=50)->(200/1=200)Mhz
413 		 */
414 		reg = readl_relaxed(S5P_CLK_DIV2);
415 		reg &= ~(S5P_CLKDIV2_G3D_MASK | S5P_CLKDIV2_MFC_MASK);
416 		reg |= (clkdiv_val[index][10] << S5P_CLKDIV2_G3D_SHIFT) |
417 			(clkdiv_val[index][9] << S5P_CLKDIV2_MFC_SHIFT);
418 		writel_relaxed(reg, S5P_CLK_DIV2);
419 
420 		/* For MFC, G3D dividing */
421 		do {
422 			reg = readl_relaxed(S5P_CLKDIV_STAT0);
423 		} while (reg & ((1 << 16) | (1 << 17)));
424 
425 		/* 9. Change MPLL to APLL in MSYS_MUX */
426 		reg = readl_relaxed(S5P_CLK_SRC0);
427 		reg &= ~(S5P_CLKSRC0_MUX200_MASK);
428 		reg |= (0x0 << S5P_CLKSRC0_MUX200_SHIFT);
429 		writel_relaxed(reg, S5P_CLK_SRC0);
430 
431 		do {
432 			reg = readl_relaxed(S5P_CLKMUX_STAT0);
433 		} while (reg & (0x1 << 18));
434 
435 		/*
436 		 * 10. DMC1 refresh counter
437 		 * L4 : DMC1 = 100Mhz 7.8us/(1/100) = 0x30c
438 		 * Others : DMC1 = 200Mhz 7.8us/(1/200) = 0x618
439 		 */
440 		if (!bus_speed_changing)
441 			s5pv210_set_refresh(DMC1, 200000);
442 	}
443 
444 	/*
445 	 * L4 level need to change memory bus speed, hence onedram clock divier
446 	 * and memory refresh parameter should be changed
447 	 */
448 	if (bus_speed_changing) {
449 		reg = readl_relaxed(S5P_CLK_DIV6);
450 		reg &= ~S5P_CLKDIV6_ONEDRAM_MASK;
451 		reg |= (clkdiv_val[index][8] << S5P_CLKDIV6_ONEDRAM_SHIFT);
452 		writel_relaxed(reg, S5P_CLK_DIV6);
453 
454 		do {
455 			reg = readl_relaxed(S5P_CLKDIV_STAT1);
456 		} while (reg & (1 << 15));
457 
458 		/* Reconfigure DRAM refresh counter value */
459 		if (index != L4) {
460 			/*
461 			 * DMC0 : 166Mhz
462 			 * DMC1 : 200Mhz
463 			 */
464 			s5pv210_set_refresh(DMC0, 166000);
465 			s5pv210_set_refresh(DMC1, 200000);
466 		} else {
467 			/*
468 			 * DMC0 : 83Mhz
469 			 * DMC1 : 100Mhz
470 			 */
471 			s5pv210_set_refresh(DMC0, 83000);
472 			s5pv210_set_refresh(DMC1, 100000);
473 		}
474 	}
475 
476 	if (new_freq < old_freq) {
477 		regulator_set_voltage(int_regulator,
478 				int_volt, int_volt_max);
479 
480 		regulator_set_voltage(arm_regulator,
481 				arm_volt, arm_volt_max);
482 	}
483 
484 	printk(KERN_DEBUG "Perf changed[L%d]\n", index);
485 
486 exit:
487 	mutex_unlock(&set_freq_lock);
488 	return ret;
489 }
490 
491 static int check_mem_type(void __iomem *dmc_reg)
492 {
493 	unsigned long val;
494 
495 	val = readl_relaxed(dmc_reg + 0x4);
496 	val = (val & (0xf << 8));
497 
498 	return val >> 8;
499 }
500 
501 static int s5pv210_cpu_init(struct cpufreq_policy *policy)
502 {
503 	unsigned long mem_type;
504 	int ret;
505 
506 	policy->clk = clk_get(NULL, "armclk");
507 	if (IS_ERR(policy->clk))
508 		return PTR_ERR(policy->clk);
509 
510 	dmc0_clk = clk_get(NULL, "sclk_dmc0");
511 	if (IS_ERR(dmc0_clk)) {
512 		ret = PTR_ERR(dmc0_clk);
513 		goto out_dmc0;
514 	}
515 
516 	dmc1_clk = clk_get(NULL, "hclk_msys");
517 	if (IS_ERR(dmc1_clk)) {
518 		ret = PTR_ERR(dmc1_clk);
519 		goto out_dmc1;
520 	}
521 
522 	if (policy->cpu != 0) {
523 		ret = -EINVAL;
524 		goto out_dmc1;
525 	}
526 
527 	/*
528 	 * check_mem_type : This driver only support LPDDR & LPDDR2.
529 	 * other memory type is not supported.
530 	 */
531 	mem_type = check_mem_type(dmc_base[0]);
532 
533 	if ((mem_type != LPDDR) && (mem_type != LPDDR2)) {
534 		pr_err("CPUFreq doesn't support this memory type\n");
535 		ret = -EINVAL;
536 		goto out_dmc1;
537 	}
538 
539 	/* Find current refresh counter and frequency each DMC */
540 	s5pv210_dram_conf[0].refresh = (readl_relaxed(dmc_base[0] + 0x30) * 1000);
541 	s5pv210_dram_conf[0].freq = clk_get_rate(dmc0_clk);
542 
543 	s5pv210_dram_conf[1].refresh = (readl_relaxed(dmc_base[1] + 0x30) * 1000);
544 	s5pv210_dram_conf[1].freq = clk_get_rate(dmc1_clk);
545 
546 	policy->suspend_freq = SLEEP_FREQ;
547 	return cpufreq_generic_init(policy, s5pv210_freq_table, 40000);
548 
549 out_dmc1:
550 	clk_put(dmc0_clk);
551 out_dmc0:
552 	clk_put(policy->clk);
553 	return ret;
554 }
555 
556 static int s5pv210_cpufreq_reboot_notifier_event(struct notifier_block *this,
557 						 unsigned long event, void *ptr)
558 {
559 	int ret;
560 
561 	ret = cpufreq_driver_target(cpufreq_cpu_get(0), SLEEP_FREQ, 0);
562 	if (ret < 0)
563 		return NOTIFY_BAD;
564 
565 	no_cpufreq_access = true;
566 	return NOTIFY_DONE;
567 }
568 
569 static struct cpufreq_driver s5pv210_driver = {
570 	.flags		= CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK,
571 	.verify		= cpufreq_generic_frequency_table_verify,
572 	.target_index	= s5pv210_target,
573 	.get		= cpufreq_generic_get,
574 	.init		= s5pv210_cpu_init,
575 	.name		= "s5pv210",
576 	.suspend	= cpufreq_generic_suspend,
577 	.resume		= cpufreq_generic_suspend, /* We need to set SLEEP FREQ again */
578 };
579 
580 static struct notifier_block s5pv210_cpufreq_reboot_notifier = {
581 	.notifier_call = s5pv210_cpufreq_reboot_notifier_event,
582 };
583 
584 static int s5pv210_cpufreq_probe(struct platform_device *pdev)
585 {
586 	struct device_node *np;
587 	int id, result = 0;
588 
589 	/*
590 	 * HACK: This is a temporary workaround to get access to clock
591 	 * and DMC controller registers directly and remove static mappings
592 	 * and dependencies on platform headers. It is necessary to enable
593 	 * S5PV210 multi-platform support and will be removed together with
594 	 * this whole driver as soon as S5PV210 gets migrated to use
595 	 * cpufreq-dt driver.
596 	 */
597 	arm_regulator = regulator_get(NULL, "vddarm");
598 	if (IS_ERR(arm_regulator)) {
599 		if (PTR_ERR(arm_regulator) == -EPROBE_DEFER)
600 			pr_debug("vddarm regulator not ready, defer\n");
601 		else
602 			pr_err("failed to get regulator vddarm\n");
603 		return PTR_ERR(arm_regulator);
604 	}
605 
606 	int_regulator = regulator_get(NULL, "vddint");
607 	if (IS_ERR(int_regulator)) {
608 		if (PTR_ERR(int_regulator) == -EPROBE_DEFER)
609 			pr_debug("vddint regulator not ready, defer\n");
610 		else
611 			pr_err("failed to get regulator vddint\n");
612 		result = PTR_ERR(int_regulator);
613 		goto err_int_regulator;
614 	}
615 
616 	np = of_find_compatible_node(NULL, NULL, "samsung,s5pv210-clock");
617 	if (!np) {
618 		pr_err("%s: failed to find clock controller DT node\n",
619 			__func__);
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 		pr_err("%s: failed to map clock registers\n", __func__);
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 			pr_err("%s: failed to get alias of dmc node '%pOFn'\n",
636 				__func__, np);
637 			of_node_put(np);
638 			result = id;
639 			goto err_clk_base;
640 		}
641 
642 		dmc_base[id] = of_iomap(np, 0);
643 		if (!dmc_base[id]) {
644 			pr_err("%s: failed to map dmc%d registers\n",
645 				__func__, id);
646 			of_node_put(np);
647 			result = -EFAULT;
648 			goto err_dmc;
649 		}
650 	}
651 
652 	for (id = 0; id < ARRAY_SIZE(dmc_base); ++id) {
653 		if (!dmc_base[id]) {
654 			pr_err("%s: failed to find dmc%d node\n", __func__, id);
655 			result = -ENODEV;
656 			goto err_dmc;
657 		}
658 	}
659 
660 	register_reboot_notifier(&s5pv210_cpufreq_reboot_notifier);
661 
662 	return cpufreq_register_driver(&s5pv210_driver);
663 
664 err_dmc:
665 	for (id = 0; id < ARRAY_SIZE(dmc_base); ++id)
666 		if (dmc_base[id]) {
667 			iounmap(dmc_base[id]);
668 			dmc_base[id] = NULL;
669 		}
670 
671 err_clk_base:
672 	iounmap(clk_base);
673 
674 err_clock:
675 	regulator_put(int_regulator);
676 
677 err_int_regulator:
678 	regulator_put(arm_regulator);
679 
680 	return result;
681 }
682 
683 static struct platform_driver s5pv210_cpufreq_platdrv = {
684 	.driver = {
685 		.name	= "s5pv210-cpufreq",
686 	},
687 	.probe = s5pv210_cpufreq_probe,
688 };
689 builtin_platform_driver(s5pv210_cpufreq_platdrv);
690