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1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2010 Samsung Electronics Co., Ltd.
4  *		http://www.samsung.com
5  *
6  * CPU frequency scaling for S5PC110/S5PV210
7 */
8 
9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10 
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 
24 static void __iomem *clk_base;
25 static 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 
83 static struct clk *dmc0_clk;
84 static struct clk *dmc1_clk;
85 static 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 freqency can be updated anymore */
95 static bool no_cpufreq_access;
96 
97 /*
98  * DRAM configurations to calculate refresh counter for changing
99  * frequency of memory.
100  */
101 struct dram_conf {
102 	unsigned long freq;	/* HZ */
103 	unsigned long refresh;	/* DRAM refresh counter * 1000 */
104 };
105 
106 /* DRAM configuration (DMC0 and DMC1) */
107 static struct dram_conf s5pv210_dram_conf[2];
108 
109 enum perf_level {
110 	L0, L1, L2, L3, L4,
111 };
112 
113 enum s5pv210_mem_type {
114 	LPDDR	= 0x1,
115 	LPDDR2	= 0x2,
116 	DDR2	= 0x4,
117 };
118 
119 enum s5pv210_dmc_port {
120 	DMC0 = 0,
121 	DMC1,
122 };
123 
124 static 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 
133 static struct regulator *arm_regulator;
134 static struct regulator *int_regulator;
135 
136 struct s5pv210_dvs_conf {
137 	int arm_volt;	/* uV */
138 	int int_volt;	/* uV */
139 };
140 
141 static const int arm_volt_max = 1350000;
142 static const int int_volt_max = 1250000;
143 
144 static 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 
167 static u32 clkdiv_val[5][11] = {
168 	/*
169 	 * Clock divider value for following
170 	 * { 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 counter
193  * accoriding to operating frequency of DRAM
194  * ch: DMC port number 0 or 1
195  * freq: Operating frequency of DRAM(KHz)
196  */
s5pv210_set_refresh(enum s5pv210_dmc_port ch,unsigned long freq)197 static 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 
s5pv210_target(struct cpufreq_policy * policy,unsigned int index)223 static 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);
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 minimum
274 		 * temporary clock while changing divider.
275 		 * expected clock is 83Mhz : 7.8usec/(1/83Mhz) = 0x287
276 		 */
277 		if (pll_changing)
278 			s5pv210_set_refresh(DMC1, 83000);
279 		else
280 			s5pv210_set_refresh(DMC1, 100000);
281 
282 		s5pv210_set_refresh(DMC0, 83000);
283 	}
284 
285 	/*
286 	 * APLL should be changed in this level
287 	 * APLL -> MPLL(for stable transition) -> APLL
288 	 * 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 G3D
294 		 * SCLKA2M(200/1=200)->(200/4=50)Mhz
295 		 */
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 MUX
309 		 * (200/4=50)->(667/4=166)Mhz
310 		 */
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) is
323 		 * true refresh counter is already programed in upper
324 		 * code. 0x287@83Mhz
325 		 */
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 	else
370 		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 APLL
380 		 * 6-1. Set PMS values
381 		 * 6-2. Wait untile the PLL is locked
382 		 */
383 		if (index == L0)
384 			writel_relaxed(APLL_VAL_1000, S5P_APLL_CON);
385 		else
386 			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 souce clock from SCLKMPLL(667Mhz)
394 		 * to SCLKA2M(200Mhz) in MFC_MUX and G3D MUX
395 		 * (667/4=166)->(200/4=50)Mhz
396 		 */
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 G3D
409 		 * (200/4=50)->(200/1=200)Mhz
410 		 */
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 counter
434 		 * L4 : DMC1 = 100Mhz 7.8us/(1/100) = 0x30c
435 		 * Others : DMC1 = 200Mhz 7.8us/(1/200) = 0x618
436 		 */
437 		if (!bus_speed_changing)
438 			s5pv210_set_refresh(DMC1, 200000);
439 	}
440 
441 	/*
442 	 * L4 level need to change memory bus speed, hence onedram clock divier
443 	 * and memory refresh parameter should be changed
444 	 */
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 : 166Mhz
459 			 * DMC1 : 200Mhz
460 			 */
461 			s5pv210_set_refresh(DMC0, 166000);
462 			s5pv210_set_refresh(DMC1, 200000);
463 		} else {
464 			/*
465 			 * DMC0 : 83Mhz
466 			 * DMC1 : 100Mhz
467 			 */
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 
483 exit:
484 	mutex_unlock(&set_freq_lock);
485 	return ret;
486 }
487 
check_mem_type(void __iomem * dmc_reg)488 static 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 
s5pv210_cpu_init(struct cpufreq_policy * policy)498 static 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 
547 out_dmc1:
548 	clk_put(dmc0_clk);
549 out_dmc0:
550 	clk_put(policy->clk);
551 	return ret;
552 }
553 
s5pv210_cpufreq_reboot_notifier_event(struct notifier_block * this,unsigned long event,void * ptr)554 static 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 
576 static struct cpufreq_driver s5pv210_driver = {
577 	.flags		= CPUFREQ_STICKY | 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 
587 static struct notifier_block s5pv210_cpufreq_reboot_notifier = {
588 	.notifier_call = s5pv210_cpufreq_reboot_notifier_event,
589 };
590 
s5pv210_cpufreq_probe(struct platform_device * pdev)591 static 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 clock
599 	 * and DMC controller registers directly and remove static mappings
600 	 * and dependencies on platform headers. It is necessary to enable
601 	 * S5PV210 multi-platform support and will be removed together with
602 	 * this whole driver as soon as S5PV210 gets migrated to use
603 	 * 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 
662 err_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 
669 err_clk_base:
670 	iounmap(clk_base);
671 
672 err_clock:
673 	regulator_put(int_regulator);
674 
675 err_int_regulator:
676 	regulator_put(arm_regulator);
677 
678 	return result;
679 }
680 
681 static struct platform_driver s5pv210_cpufreq_platdrv = {
682 	.driver = {
683 		.name	= "s5pv210-cpufreq",
684 	},
685 	.probe = s5pv210_cpufreq_probe,
686 };
687 builtin_platform_driver(s5pv210_cpufreq_platdrv);
688