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
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 changing
99 * 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 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 * according to operating frequency of DRAM
194 * ch: DMC port number 0 or 1
195 * 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, target_freq: old_freq, efficiencies: 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(regulator: arm_regulator,
253 min_uV: arm_volt, max_uV: arm_volt_max);
254 if (ret)
255 goto exit;
256
257 ret = regulator_set_voltage(regulator: int_regulator,
258 min_uV: int_volt, max_uV: 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(ch: DMC1, freq: 83000);
279 else
280 s5pv210_set_refresh(ch: DMC1, freq: 100000);
281
282 s5pv210_set_refresh(ch: DMC0, freq: 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 programmed in upper
324 * code. 0x287@83Mhz
325 */
326 if (!bus_speed_changing)
327 s5pv210_set_refresh(ch: DMC1, freq: 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 until 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 source 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(ch: DMC1, freq: 200000);
439 }
440
441 /*
442 * L4 level needs to change memory bus speed, hence ONEDRAM clock
443 * divider 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(ch: DMC0, freq: 166000);
462 s5pv210_set_refresh(ch: DMC1, freq: 200000);
463 } else {
464 /*
465 * DMC0 : 83Mhz
466 * DMC1 : 100Mhz
467 */
468 s5pv210_set_refresh(ch: DMC0, freq: 83000);
469 s5pv210_set_refresh(ch: DMC1, freq: 100000);
470 }
471 }
472
473 if (new_freq < old_freq) {
474 regulator_set_voltage(regulator: int_regulator,
475 min_uV: int_volt, max_uV: int_volt_max);
476
477 regulator_set_voltage(regulator: arm_regulator,
478 min_uV: arm_volt, max_uV: arm_volt_max);
479 }
480
481 pr_debug("Perf changed[L%d]\n", index);
482
483exit:
484 mutex_unlock(lock: &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, id: "armclk");
504 if (IS_ERR(ptr: policy->clk))
505 return PTR_ERR(ptr: policy->clk);
506
507 dmc0_clk = clk_get(NULL, id: "sclk_dmc0");
508 if (IS_ERR(ptr: dmc0_clk)) {
509 ret = PTR_ERR(ptr: dmc0_clk);
510 goto out_dmc0;
511 }
512
513 dmc1_clk = clk_get(NULL, id: "hclk_msys");
514 if (IS_ERR(ptr: dmc1_clk)) {
515 ret = PTR_ERR(ptr: 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_reg: 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(clk: 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(clk: dmc1_clk);
542
543 policy->suspend_freq = SLEEP_FREQ;
544 cpufreq_generic_init(policy, table: s5pv210_freq_table, transition_latency: 40000);
545 return 0;
546
547out_dmc1:
548 clk_put(clk: dmc0_clk);
549out_dmc0:
550 clk_put(clk: 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(cpu: 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, relation: 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 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, id: "vddarm");
606 if (IS_ERR(ptr: arm_regulator))
607 return dev_err_probe(dev, err: PTR_ERR(ptr: arm_regulator),
608 fmt: "failed to get regulator vddarm\n");
609
610 int_regulator = regulator_get(NULL, id: "vddint");
611 if (IS_ERR(ptr: int_regulator)) {
612 result = dev_err_probe(dev, err: PTR_ERR(ptr: int_regulator),
613 fmt: "failed to get regulator vddint\n");
614 goto err_int_regulator;
615 }
616
617 np = of_find_compatible_node(NULL, NULL, compat: "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(node: np, index: 0);
625 of_node_put(node: 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, stem: "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(node: np);
637 result = id;
638 goto err_clk_base;
639 }
640
641 dmc_base[id] = of_iomap(node: np, index: 0);
642 if (!dmc_base[id]) {
643 dev_err(dev, "failed to map dmc%d registers\n", id);
644 of_node_put(node: 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(driver_data: &s5pv210_driver);
661
662err_dmc:
663 for (id = 0; id < ARRAY_SIZE(dmc_base); ++id)
664 if (dmc_base[id]) {
665 iounmap(addr: dmc_base[id]);
666 dmc_base[id] = NULL;
667 }
668
669err_clk_base:
670 iounmap(addr: clk_base);
671
672err_clock:
673 regulator_put(regulator: int_regulator);
674
675err_int_regulator:
676 regulator_put(regulator: 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

source code of linux/drivers/cpufreq/s5pv210-cpufreq.c