1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * CPU frequency scaling support for Armada 37xx platform.
4  *
5  * Copyright (C) 2017 Marvell
6  *
7  * Gregory CLEMENT <gregory.clement@free-electrons.com>
8  */
9 
10 #include <linux/clk.h>
11 #include <linux/cpu.h>
12 #include <linux/cpufreq.h>
13 #include <linux/err.h>
14 #include <linux/interrupt.h>
15 #include <linux/io.h>
16 #include <linux/mfd/syscon.h>
17 #include <linux/module.h>
18 #include <linux/of_address.h>
19 #include <linux/of_device.h>
20 #include <linux/of_irq.h>
21 #include <linux/platform_device.h>
22 #include <linux/pm_opp.h>
23 #include <linux/regmap.h>
24 #include <linux/slab.h>
25 
26 #include "cpufreq-dt.h"
27 
28 /* Clk register set */
29 #define ARMADA_37XX_CLK_TBG_SEL		0
30 #define ARMADA_37XX_CLK_TBG_SEL_CPU_OFF	22
31 
32 /* Power management in North Bridge register set */
33 #define ARMADA_37XX_NB_L0L1	0x18
34 #define ARMADA_37XX_NB_L2L3	0x1C
35 #define  ARMADA_37XX_NB_TBG_DIV_OFF	13
36 #define  ARMADA_37XX_NB_TBG_DIV_MASK	0x7
37 #define  ARMADA_37XX_NB_CLK_SEL_OFF	11
38 #define  ARMADA_37XX_NB_CLK_SEL_MASK	0x1
39 #define  ARMADA_37XX_NB_CLK_SEL_TBG	0x1
40 #define  ARMADA_37XX_NB_TBG_SEL_OFF	9
41 #define  ARMADA_37XX_NB_TBG_SEL_MASK	0x3
42 #define  ARMADA_37XX_NB_VDD_SEL_OFF	6
43 #define  ARMADA_37XX_NB_VDD_SEL_MASK	0x3
44 #define  ARMADA_37XX_NB_CONFIG_SHIFT	16
45 #define ARMADA_37XX_NB_DYN_MOD	0x24
46 #define  ARMADA_37XX_NB_CLK_SEL_EN	BIT(26)
47 #define  ARMADA_37XX_NB_TBG_EN		BIT(28)
48 #define  ARMADA_37XX_NB_DIV_EN		BIT(29)
49 #define  ARMADA_37XX_NB_VDD_EN		BIT(30)
50 #define  ARMADA_37XX_NB_DFS_EN		BIT(31)
51 #define ARMADA_37XX_NB_CPU_LOAD 0x30
52 #define  ARMADA_37XX_NB_CPU_LOAD_MASK	0x3
53 #define  ARMADA_37XX_DVFS_LOAD_0	0
54 #define  ARMADA_37XX_DVFS_LOAD_1	1
55 #define  ARMADA_37XX_DVFS_LOAD_2	2
56 #define  ARMADA_37XX_DVFS_LOAD_3	3
57 
58 /* AVS register set */
59 #define ARMADA_37XX_AVS_CTL0		0x0
60 #define	 ARMADA_37XX_AVS_ENABLE		BIT(30)
61 #define	 ARMADA_37XX_AVS_HIGH_VDD_LIMIT	16
62 #define	 ARMADA_37XX_AVS_LOW_VDD_LIMIT	22
63 #define	 ARMADA_37XX_AVS_VDD_MASK	0x3F
64 #define ARMADA_37XX_AVS_CTL2		0x8
65 #define	 ARMADA_37XX_AVS_LOW_VDD_EN	BIT(6)
66 #define ARMADA_37XX_AVS_VSET(x)	    (0x1C + 4 * (x))
67 
68 /*
69  * On Armada 37xx the Power management manages 4 level of CPU load,
70  * each level can be associated with a CPU clock source, a CPU
71  * divider, a VDD level, etc...
72  */
73 #define LOAD_LEVEL_NR	4
74 
75 #define MIN_VOLT_MV 1000
76 #define MIN_VOLT_MV_FOR_L1_1000MHZ 1108
77 #define MIN_VOLT_MV_FOR_L1_1200MHZ 1155
78 
79 /*  AVS value for the corresponding voltage (in mV) */
80 static int avs_map[] = {
81 	747, 758, 770, 782, 793, 805, 817, 828, 840, 852, 863, 875, 887, 898,
82 	910, 922, 933, 945, 957, 968, 980, 992, 1003, 1015, 1027, 1038, 1050,
83 	1062, 1073, 1085, 1097, 1108, 1120, 1132, 1143, 1155, 1167, 1178, 1190,
84 	1202, 1213, 1225, 1237, 1248, 1260, 1272, 1283, 1295, 1307, 1318, 1330,
85 	1342
86 };
87 
88 struct armada37xx_cpufreq_state {
89 	struct platform_device *pdev;
90 	struct device *cpu_dev;
91 	struct regmap *regmap;
92 	u32 nb_l0l1;
93 	u32 nb_l2l3;
94 	u32 nb_dyn_mod;
95 	u32 nb_cpu_load;
96 };
97 
98 static struct armada37xx_cpufreq_state *armada37xx_cpufreq_state;
99 
100 struct armada_37xx_dvfs {
101 	u32 cpu_freq_max;
102 	u8 divider[LOAD_LEVEL_NR];
103 	u32 avs[LOAD_LEVEL_NR];
104 };
105 
106 static struct armada_37xx_dvfs armada_37xx_dvfs[] = {
107 	{.cpu_freq_max = 1200*1000*1000, .divider = {1, 2, 4, 6} },
108 	{.cpu_freq_max = 1000*1000*1000, .divider = {1, 2, 4, 5} },
109 	{.cpu_freq_max = 800*1000*1000,  .divider = {1, 2, 3, 4} },
110 	{.cpu_freq_max = 600*1000*1000,  .divider = {2, 4, 5, 6} },
111 };
112 
113 static struct armada_37xx_dvfs *armada_37xx_cpu_freq_info_get(u32 freq)
114 {
115 	int i;
116 
117 	for (i = 0; i < ARRAY_SIZE(armada_37xx_dvfs); i++) {
118 		if (freq == armada_37xx_dvfs[i].cpu_freq_max)
119 			return &armada_37xx_dvfs[i];
120 	}
121 
122 	pr_err("Unsupported CPU frequency %d MHz\n", freq/1000000);
123 	return NULL;
124 }
125 
126 /*
127  * Setup the four level managed by the hardware. Once the four level
128  * will be configured then the DVFS will be enabled.
129  */
130 static void __init armada37xx_cpufreq_dvfs_setup(struct regmap *base,
131 						 struct regmap *clk_base, u8 *divider)
132 {
133 	u32 cpu_tbg_sel;
134 	int load_lvl;
135 
136 	/* Determine to which TBG clock is CPU connected */
137 	regmap_read(clk_base, ARMADA_37XX_CLK_TBG_SEL, &cpu_tbg_sel);
138 	cpu_tbg_sel >>= ARMADA_37XX_CLK_TBG_SEL_CPU_OFF;
139 	cpu_tbg_sel &= ARMADA_37XX_NB_TBG_SEL_MASK;
140 
141 	for (load_lvl = 0; load_lvl < LOAD_LEVEL_NR; load_lvl++) {
142 		unsigned int reg, mask, val, offset = 0;
143 
144 		if (load_lvl <= ARMADA_37XX_DVFS_LOAD_1)
145 			reg = ARMADA_37XX_NB_L0L1;
146 		else
147 			reg = ARMADA_37XX_NB_L2L3;
148 
149 		if (load_lvl == ARMADA_37XX_DVFS_LOAD_0 ||
150 		    load_lvl == ARMADA_37XX_DVFS_LOAD_2)
151 			offset += ARMADA_37XX_NB_CONFIG_SHIFT;
152 
153 		/* Set cpu clock source, for all the level we use TBG */
154 		val = ARMADA_37XX_NB_CLK_SEL_TBG << ARMADA_37XX_NB_CLK_SEL_OFF;
155 		mask = (ARMADA_37XX_NB_CLK_SEL_MASK
156 			<< ARMADA_37XX_NB_CLK_SEL_OFF);
157 
158 		/* Set TBG index, for all levels we use the same TBG */
159 		val = cpu_tbg_sel << ARMADA_37XX_NB_TBG_SEL_OFF;
160 		mask = (ARMADA_37XX_NB_TBG_SEL_MASK
161 			<< ARMADA_37XX_NB_TBG_SEL_OFF);
162 
163 		/*
164 		 * Set cpu divider based on the pre-computed array in
165 		 * order to have balanced step.
166 		 */
167 		val |= divider[load_lvl] << ARMADA_37XX_NB_TBG_DIV_OFF;
168 		mask |= (ARMADA_37XX_NB_TBG_DIV_MASK
169 			<< ARMADA_37XX_NB_TBG_DIV_OFF);
170 
171 		/* Set VDD divider which is actually the load level. */
172 		val |= load_lvl << ARMADA_37XX_NB_VDD_SEL_OFF;
173 		mask |= (ARMADA_37XX_NB_VDD_SEL_MASK
174 			<< ARMADA_37XX_NB_VDD_SEL_OFF);
175 
176 		val <<= offset;
177 		mask <<= offset;
178 
179 		regmap_update_bits(base, reg, mask, val);
180 	}
181 }
182 
183 /*
184  * Find out the armada 37x supported AVS value whose voltage value is
185  * the round-up closest to the target voltage value.
186  */
187 static u32 armada_37xx_avs_val_match(int target_vm)
188 {
189 	u32 avs;
190 
191 	/* Find out the round-up closest supported voltage value */
192 	for (avs = 0; avs < ARRAY_SIZE(avs_map); avs++)
193 		if (avs_map[avs] >= target_vm)
194 			break;
195 
196 	/*
197 	 * If all supported voltages are smaller than target one,
198 	 * choose the largest supported voltage
199 	 */
200 	if (avs == ARRAY_SIZE(avs_map))
201 		avs = ARRAY_SIZE(avs_map) - 1;
202 
203 	return avs;
204 }
205 
206 /*
207  * For Armada 37xx soc, L0(VSET0) VDD AVS value is set to SVC revision
208  * value or a default value when SVC is not supported.
209  * - L0 can be read out from the register of AVS_CTRL_0 and L0 voltage
210  *   can be got from the mapping table of avs_map.
211  * - L1 voltage should be about 100mv smaller than L0 voltage
212  * - L2 & L3 voltage should be about 150mv smaller than L0 voltage.
213  * This function calculates L1 & L2 & L3 AVS values dynamically based
214  * on L0 voltage and fill all AVS values to the AVS value table.
215  * When base CPU frequency is 1000 or 1200 MHz then there is additional
216  * minimal avs value for load L1.
217  */
218 static void __init armada37xx_cpufreq_avs_configure(struct regmap *base,
219 						struct armada_37xx_dvfs *dvfs)
220 {
221 	unsigned int target_vm;
222 	int load_level = 0;
223 	u32 l0_vdd_min;
224 
225 	if (base == NULL)
226 		return;
227 
228 	/* Get L0 VDD min value */
229 	regmap_read(base, ARMADA_37XX_AVS_CTL0, &l0_vdd_min);
230 	l0_vdd_min = (l0_vdd_min >> ARMADA_37XX_AVS_LOW_VDD_LIMIT) &
231 		ARMADA_37XX_AVS_VDD_MASK;
232 	if (l0_vdd_min >= ARRAY_SIZE(avs_map))  {
233 		pr_err("L0 VDD MIN %d is not correct.\n", l0_vdd_min);
234 		return;
235 	}
236 	dvfs->avs[0] = l0_vdd_min;
237 
238 	if (avs_map[l0_vdd_min] <= MIN_VOLT_MV) {
239 		/*
240 		 * If L0 voltage is smaller than 1000mv, then all VDD sets
241 		 * use L0 voltage;
242 		 */
243 		u32 avs_min = armada_37xx_avs_val_match(MIN_VOLT_MV);
244 
245 		for (load_level = 1; load_level < LOAD_LEVEL_NR; load_level++)
246 			dvfs->avs[load_level] = avs_min;
247 
248 		/*
249 		 * Set the avs values for load L0 and L1 when base CPU frequency
250 		 * is 1000/1200 MHz to its typical initial values according to
251 		 * the Armada 3700 Hardware Specifications.
252 		 */
253 		if (dvfs->cpu_freq_max >= 1000*1000*1000) {
254 			if (dvfs->cpu_freq_max >= 1200*1000*1000)
255 				avs_min = armada_37xx_avs_val_match(MIN_VOLT_MV_FOR_L1_1200MHZ);
256 			else
257 				avs_min = armada_37xx_avs_val_match(MIN_VOLT_MV_FOR_L1_1000MHZ);
258 			dvfs->avs[0] = dvfs->avs[1] = avs_min;
259 		}
260 
261 		return;
262 	}
263 
264 	/*
265 	 * L1 voltage is equal to L0 voltage - 100mv and it must be
266 	 * larger than 1000mv
267 	 */
268 
269 	target_vm = avs_map[l0_vdd_min] - 100;
270 	target_vm = target_vm > MIN_VOLT_MV ? target_vm : MIN_VOLT_MV;
271 	dvfs->avs[1] = armada_37xx_avs_val_match(target_vm);
272 
273 	/*
274 	 * L2 & L3 voltage is equal to L0 voltage - 150mv and it must
275 	 * be larger than 1000mv
276 	 */
277 	target_vm = avs_map[l0_vdd_min] - 150;
278 	target_vm = target_vm > MIN_VOLT_MV ? target_vm : MIN_VOLT_MV;
279 	dvfs->avs[2] = dvfs->avs[3] = armada_37xx_avs_val_match(target_vm);
280 
281 	/*
282 	 * Fix the avs value for load L1 when base CPU frequency is 1000/1200 MHz,
283 	 * otherwise the CPU gets stuck when switching from load L1 to load L0.
284 	 * Also ensure that avs value for load L1 is not higher than for L0.
285 	 */
286 	if (dvfs->cpu_freq_max >= 1000*1000*1000) {
287 		u32 avs_min_l1;
288 
289 		if (dvfs->cpu_freq_max >= 1200*1000*1000)
290 			avs_min_l1 = armada_37xx_avs_val_match(MIN_VOLT_MV_FOR_L1_1200MHZ);
291 		else
292 			avs_min_l1 = armada_37xx_avs_val_match(MIN_VOLT_MV_FOR_L1_1000MHZ);
293 
294 		if (avs_min_l1 > dvfs->avs[0])
295 			avs_min_l1 = dvfs->avs[0];
296 
297 		if (dvfs->avs[1] < avs_min_l1)
298 			dvfs->avs[1] = avs_min_l1;
299 	}
300 }
301 
302 static void __init armada37xx_cpufreq_avs_setup(struct regmap *base,
303 						struct armada_37xx_dvfs *dvfs)
304 {
305 	unsigned int avs_val = 0;
306 	int load_level = 0;
307 
308 	if (base == NULL)
309 		return;
310 
311 	/* Disable AVS before the configuration */
312 	regmap_update_bits(base, ARMADA_37XX_AVS_CTL0,
313 			   ARMADA_37XX_AVS_ENABLE, 0);
314 
315 
316 	/* Enable low voltage mode */
317 	regmap_update_bits(base, ARMADA_37XX_AVS_CTL2,
318 			   ARMADA_37XX_AVS_LOW_VDD_EN,
319 			   ARMADA_37XX_AVS_LOW_VDD_EN);
320 
321 
322 	for (load_level = 1; load_level < LOAD_LEVEL_NR; load_level++) {
323 		avs_val = dvfs->avs[load_level];
324 		regmap_update_bits(base, ARMADA_37XX_AVS_VSET(load_level-1),
325 		    ARMADA_37XX_AVS_VDD_MASK << ARMADA_37XX_AVS_HIGH_VDD_LIMIT |
326 		    ARMADA_37XX_AVS_VDD_MASK << ARMADA_37XX_AVS_LOW_VDD_LIMIT,
327 		    avs_val << ARMADA_37XX_AVS_HIGH_VDD_LIMIT |
328 		    avs_val << ARMADA_37XX_AVS_LOW_VDD_LIMIT);
329 	}
330 
331 	/* Enable AVS after the configuration */
332 	regmap_update_bits(base, ARMADA_37XX_AVS_CTL0,
333 			   ARMADA_37XX_AVS_ENABLE,
334 			   ARMADA_37XX_AVS_ENABLE);
335 
336 }
337 
338 static void armada37xx_cpufreq_disable_dvfs(struct regmap *base)
339 {
340 	unsigned int reg = ARMADA_37XX_NB_DYN_MOD,
341 		mask = ARMADA_37XX_NB_DFS_EN;
342 
343 	regmap_update_bits(base, reg, mask, 0);
344 }
345 
346 static void __init armada37xx_cpufreq_enable_dvfs(struct regmap *base)
347 {
348 	unsigned int val, reg = ARMADA_37XX_NB_CPU_LOAD,
349 		mask = ARMADA_37XX_NB_CPU_LOAD_MASK;
350 
351 	/* Start with the highest load (0) */
352 	val = ARMADA_37XX_DVFS_LOAD_0;
353 	regmap_update_bits(base, reg, mask, val);
354 
355 	/* Now enable DVFS for the CPUs */
356 	reg = ARMADA_37XX_NB_DYN_MOD;
357 	mask =	ARMADA_37XX_NB_CLK_SEL_EN | ARMADA_37XX_NB_TBG_EN |
358 		ARMADA_37XX_NB_DIV_EN | ARMADA_37XX_NB_VDD_EN |
359 		ARMADA_37XX_NB_DFS_EN;
360 
361 	regmap_update_bits(base, reg, mask, mask);
362 }
363 
364 static int armada37xx_cpufreq_suspend(struct cpufreq_policy *policy)
365 {
366 	struct armada37xx_cpufreq_state *state = armada37xx_cpufreq_state;
367 
368 	regmap_read(state->regmap, ARMADA_37XX_NB_L0L1, &state->nb_l0l1);
369 	regmap_read(state->regmap, ARMADA_37XX_NB_L2L3, &state->nb_l2l3);
370 	regmap_read(state->regmap, ARMADA_37XX_NB_CPU_LOAD,
371 		    &state->nb_cpu_load);
372 	regmap_read(state->regmap, ARMADA_37XX_NB_DYN_MOD, &state->nb_dyn_mod);
373 
374 	return 0;
375 }
376 
377 static int armada37xx_cpufreq_resume(struct cpufreq_policy *policy)
378 {
379 	struct armada37xx_cpufreq_state *state = armada37xx_cpufreq_state;
380 
381 	/* Ensure DVFS is disabled otherwise the following registers are RO */
382 	armada37xx_cpufreq_disable_dvfs(state->regmap);
383 
384 	regmap_write(state->regmap, ARMADA_37XX_NB_L0L1, state->nb_l0l1);
385 	regmap_write(state->regmap, ARMADA_37XX_NB_L2L3, state->nb_l2l3);
386 	regmap_write(state->regmap, ARMADA_37XX_NB_CPU_LOAD,
387 		     state->nb_cpu_load);
388 
389 	/*
390 	 * NB_DYN_MOD register is the one that actually enable back DVFS if it
391 	 * was enabled before the suspend operation. This must be done last
392 	 * otherwise other registers are not writable.
393 	 */
394 	regmap_write(state->regmap, ARMADA_37XX_NB_DYN_MOD, state->nb_dyn_mod);
395 
396 	return 0;
397 }
398 
399 static int __init armada37xx_cpufreq_driver_init(void)
400 {
401 	struct cpufreq_dt_platform_data pdata;
402 	struct armada_37xx_dvfs *dvfs;
403 	struct platform_device *pdev;
404 	unsigned long freq;
405 	unsigned int base_frequency;
406 	struct regmap *nb_clk_base, *nb_pm_base, *avs_base;
407 	struct device *cpu_dev;
408 	int load_lvl, ret;
409 	struct clk *clk, *parent;
410 
411 	nb_clk_base =
412 		syscon_regmap_lookup_by_compatible("marvell,armada-3700-periph-clock-nb");
413 	if (IS_ERR(nb_clk_base))
414 		return -ENODEV;
415 
416 	nb_pm_base =
417 		syscon_regmap_lookup_by_compatible("marvell,armada-3700-nb-pm");
418 
419 	if (IS_ERR(nb_pm_base))
420 		return -ENODEV;
421 
422 	avs_base =
423 		syscon_regmap_lookup_by_compatible("marvell,armada-3700-avs");
424 
425 	/* if AVS is not present don't use it but still try to setup dvfs */
426 	if (IS_ERR(avs_base)) {
427 		pr_info("Syscon failed for Adapting Voltage Scaling: skip it\n");
428 		avs_base = NULL;
429 	}
430 	/* Before doing any configuration on the DVFS first, disable it */
431 	armada37xx_cpufreq_disable_dvfs(nb_pm_base);
432 
433 	/*
434 	 * On CPU 0 register the operating points supported (which are
435 	 * the nominal CPU frequency and full integer divisions of
436 	 * it).
437 	 */
438 	cpu_dev = get_cpu_device(0);
439 	if (!cpu_dev) {
440 		dev_err(cpu_dev, "Cannot get CPU\n");
441 		return -ENODEV;
442 	}
443 
444 	clk = clk_get(cpu_dev, 0);
445 	if (IS_ERR(clk)) {
446 		dev_err(cpu_dev, "Cannot get clock for CPU0\n");
447 		return PTR_ERR(clk);
448 	}
449 
450 	parent = clk_get_parent(clk);
451 	if (IS_ERR(parent)) {
452 		dev_err(cpu_dev, "Cannot get parent clock for CPU0\n");
453 		clk_put(clk);
454 		return PTR_ERR(parent);
455 	}
456 
457 	/* Get parent CPU frequency */
458 	base_frequency =  clk_get_rate(parent);
459 
460 	if (!base_frequency) {
461 		dev_err(cpu_dev, "Failed to get parent clock rate for CPU\n");
462 		clk_put(clk);
463 		return -EINVAL;
464 	}
465 
466 	dvfs = armada_37xx_cpu_freq_info_get(base_frequency);
467 	if (!dvfs) {
468 		clk_put(clk);
469 		return -EINVAL;
470 	}
471 
472 	armada37xx_cpufreq_state = kmalloc(sizeof(*armada37xx_cpufreq_state),
473 					   GFP_KERNEL);
474 	if (!armada37xx_cpufreq_state) {
475 		clk_put(clk);
476 		return -ENOMEM;
477 	}
478 
479 	armada37xx_cpufreq_state->regmap = nb_pm_base;
480 
481 	armada37xx_cpufreq_avs_configure(avs_base, dvfs);
482 	armada37xx_cpufreq_avs_setup(avs_base, dvfs);
483 
484 	armada37xx_cpufreq_dvfs_setup(nb_pm_base, nb_clk_base, dvfs->divider);
485 	clk_put(clk);
486 
487 	for (load_lvl = ARMADA_37XX_DVFS_LOAD_0; load_lvl < LOAD_LEVEL_NR;
488 	     load_lvl++) {
489 		unsigned long u_volt = avs_map[dvfs->avs[load_lvl]] * 1000;
490 		freq = base_frequency / dvfs->divider[load_lvl];
491 		ret = dev_pm_opp_add(cpu_dev, freq, u_volt);
492 		if (ret)
493 			goto remove_opp;
494 
495 
496 	}
497 
498 	/* Now that everything is setup, enable the DVFS at hardware level */
499 	armada37xx_cpufreq_enable_dvfs(nb_pm_base);
500 
501 	memset(&pdata, 0, sizeof(pdata));
502 	pdata.suspend = armada37xx_cpufreq_suspend;
503 	pdata.resume = armada37xx_cpufreq_resume;
504 
505 	pdev = platform_device_register_data(NULL, "cpufreq-dt", -1, &pdata,
506 					     sizeof(pdata));
507 	ret = PTR_ERR_OR_ZERO(pdev);
508 	if (ret)
509 		goto disable_dvfs;
510 
511 	armada37xx_cpufreq_state->cpu_dev = cpu_dev;
512 	armada37xx_cpufreq_state->pdev = pdev;
513 	platform_set_drvdata(pdev, dvfs);
514 	return 0;
515 
516 disable_dvfs:
517 	armada37xx_cpufreq_disable_dvfs(nb_pm_base);
518 remove_opp:
519 	/* clean-up the already added opp before leaving */
520 	while (load_lvl-- > ARMADA_37XX_DVFS_LOAD_0) {
521 		freq = base_frequency / dvfs->divider[load_lvl];
522 		dev_pm_opp_remove(cpu_dev, freq);
523 	}
524 
525 	kfree(armada37xx_cpufreq_state);
526 
527 	return ret;
528 }
529 /* late_initcall, to guarantee the driver is loaded after A37xx clock driver */
530 late_initcall(armada37xx_cpufreq_driver_init);
531 
532 static void __exit armada37xx_cpufreq_driver_exit(void)
533 {
534 	struct platform_device *pdev = armada37xx_cpufreq_state->pdev;
535 	struct armada_37xx_dvfs *dvfs = platform_get_drvdata(pdev);
536 	unsigned long freq;
537 	int load_lvl;
538 
539 	platform_device_unregister(pdev);
540 
541 	armada37xx_cpufreq_disable_dvfs(armada37xx_cpufreq_state->regmap);
542 
543 	for (load_lvl = ARMADA_37XX_DVFS_LOAD_0; load_lvl < LOAD_LEVEL_NR; load_lvl++) {
544 		freq = dvfs->cpu_freq_max / dvfs->divider[load_lvl];
545 		dev_pm_opp_remove(armada37xx_cpufreq_state->cpu_dev, freq);
546 	}
547 
548 	kfree(armada37xx_cpufreq_state);
549 }
550 module_exit(armada37xx_cpufreq_driver_exit);
551 
552 static const struct of_device_id __maybe_unused armada37xx_cpufreq_of_match[] = {
553 	{ .compatible = "marvell,armada-3700-nb-pm" },
554 	{ },
555 };
556 MODULE_DEVICE_TABLE(of, armada37xx_cpufreq_of_match);
557 
558 MODULE_AUTHOR("Gregory CLEMENT <gregory.clement@free-electrons.com>");
559 MODULE_DESCRIPTION("Armada 37xx cpufreq driver");
560 MODULE_LICENSE("GPL");
561