1/*
2 * Power Management Service Unit(PMSU) support for Armada 370/XP platforms.
3 *
4 * Copyright (C) 2012 Marvell
5 *
6 * Yehuda Yitschak <yehuday@marvell.com>
7 * Gregory Clement <gregory.clement@free-electrons.com>
8 * Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
9 *
10 * This file is licensed under the terms of the GNU General Public
11 * License version 2.  This program is licensed "as is" without any
12 * warranty of any kind, whether express or implied.
13 *
14 * The Armada 370 and Armada XP SOCs have a power management service
15 * unit which is responsible for powering down and waking up CPUs and
16 * other SOC units
17 */
18
19#define pr_fmt(fmt) "mvebu-pmsu: " fmt
20
21#include <linux/clk.h>
22#include <linux/cpu_pm.h>
23#include <linux/cpufreq-dt.h>
24#include <linux/delay.h>
25#include <linux/init.h>
26#include <linux/io.h>
27#include <linux/kernel.h>
28#include <linux/mbus.h>
29#include <linux/of_address.h>
30#include <linux/of_device.h>
31#include <linux/platform_device.h>
32#include <linux/pm_opp.h>
33#include <linux/resource.h>
34#include <linux/slab.h>
35#include <linux/smp.h>
36#include <asm/cacheflush.h>
37#include <asm/cp15.h>
38#include <asm/smp_scu.h>
39#include <asm/smp_plat.h>
40#include <asm/suspend.h>
41#include <asm/tlbflush.h>
42#include "common.h"
43
44
45#define PMSU_BASE_OFFSET    0x100
46#define PMSU_REG_SIZE	    0x1000
47
48/* PMSU MP registers */
49#define PMSU_CONTROL_AND_CONFIG(cpu)	    ((cpu * 0x100) + 0x104)
50#define PMSU_CONTROL_AND_CONFIG_DFS_REQ		BIT(18)
51#define PMSU_CONTROL_AND_CONFIG_PWDDN_REQ	BIT(16)
52#define PMSU_CONTROL_AND_CONFIG_L2_PWDDN	BIT(20)
53
54#define PMSU_CPU_POWER_DOWN_CONTROL(cpu)    ((cpu * 0x100) + 0x108)
55
56#define PMSU_CPU_POWER_DOWN_DIS_SNP_Q_SKIP	BIT(0)
57
58#define PMSU_STATUS_AND_MASK(cpu)	    ((cpu * 0x100) + 0x10c)
59#define PMSU_STATUS_AND_MASK_CPU_IDLE_WAIT	BIT(16)
60#define PMSU_STATUS_AND_MASK_SNP_Q_EMPTY_WAIT	BIT(17)
61#define PMSU_STATUS_AND_MASK_IRQ_WAKEUP		BIT(20)
62#define PMSU_STATUS_AND_MASK_FIQ_WAKEUP		BIT(21)
63#define PMSU_STATUS_AND_MASK_DBG_WAKEUP		BIT(22)
64#define PMSU_STATUS_AND_MASK_IRQ_MASK		BIT(24)
65#define PMSU_STATUS_AND_MASK_FIQ_MASK		BIT(25)
66
67#define PMSU_EVENT_STATUS_AND_MASK(cpu)     ((cpu * 0x100) + 0x120)
68#define PMSU_EVENT_STATUS_AND_MASK_DFS_DONE        BIT(1)
69#define PMSU_EVENT_STATUS_AND_MASK_DFS_DONE_MASK   BIT(17)
70
71#define PMSU_BOOT_ADDR_REDIRECT_OFFSET(cpu) ((cpu * 0x100) + 0x124)
72
73/* PMSU fabric registers */
74#define L2C_NFABRIC_PM_CTL		    0x4
75#define L2C_NFABRIC_PM_CTL_PWR_DOWN		BIT(20)
76
77/* PMSU delay registers */
78#define PMSU_POWERDOWN_DELAY		    0xF04
79#define PMSU_POWERDOWN_DELAY_PMU		BIT(1)
80#define PMSU_POWERDOWN_DELAY_MASK		0xFFFE
81#define PMSU_DFLT_ARMADA38X_DELAY	        0x64
82
83/* CA9 MPcore SoC Control registers */
84
85#define MPCORE_RESET_CTL		    0x64
86#define MPCORE_RESET_CTL_L2			BIT(0)
87#define MPCORE_RESET_CTL_DEBUG			BIT(16)
88
89#define SRAM_PHYS_BASE  0xFFFF0000
90#define BOOTROM_BASE    0xFFF00000
91#define BOOTROM_SIZE    0x100000
92
93#define ARMADA_370_CRYPT0_ENG_TARGET   0x9
94#define ARMADA_370_CRYPT0_ENG_ATTR     0x1
95
96extern void ll_disable_coherency(void);
97extern void ll_enable_coherency(void);
98
99extern void armada_370_xp_cpu_resume(void);
100extern void armada_38x_cpu_resume(void);
101
102static phys_addr_t pmsu_mp_phys_base;
103static void __iomem *pmsu_mp_base;
104
105static void *mvebu_cpu_resume;
106
107static const struct of_device_id of_pmsu_table[] = {
108	{ .compatible = "marvell,armada-370-pmsu", },
109	{ .compatible = "marvell,armada-370-xp-pmsu", },
110	{ .compatible = "marvell,armada-380-pmsu", },
111	{ /* end of list */ },
112};
113
114void mvebu_pmsu_set_cpu_boot_addr(int hw_cpu, void *boot_addr)
115{
116	writel(virt_to_phys(boot_addr), pmsu_mp_base +
117		PMSU_BOOT_ADDR_REDIRECT_OFFSET(hw_cpu));
118}
119
120extern unsigned char mvebu_boot_wa_start;
121extern unsigned char mvebu_boot_wa_end;
122
123/*
124 * This function sets up the boot address workaround needed for SMP
125 * boot on Armada 375 Z1 and cpuidle on Armada 370. It unmaps the
126 * BootROM Mbus window, and instead remaps a crypto SRAM into which a
127 * custom piece of code is copied to replace the problematic BootROM.
128 */
129int mvebu_setup_boot_addr_wa(unsigned int crypto_eng_target,
130			     unsigned int crypto_eng_attribute,
131			     phys_addr_t resume_addr_reg)
132{
133	void __iomem *sram_virt_base;
134	u32 code_len = &mvebu_boot_wa_end - &mvebu_boot_wa_start;
135
136	mvebu_mbus_del_window(BOOTROM_BASE, BOOTROM_SIZE);
137	mvebu_mbus_add_window_by_id(crypto_eng_target, crypto_eng_attribute,
138				    SRAM_PHYS_BASE, SZ_64K);
139
140	sram_virt_base = ioremap(SRAM_PHYS_BASE, SZ_64K);
141	if (!sram_virt_base) {
142		pr_err("Unable to map SRAM to setup the boot address WA\n");
143		return -ENOMEM;
144	}
145
146	memcpy(sram_virt_base, &mvebu_boot_wa_start, code_len);
147
148	/*
149	 * The last word of the code copied in SRAM must contain the
150	 * physical base address of the PMSU register. We
151	 * intentionally store this address in the native endianness
152	 * of the system.
153	 */
154	__raw_writel((unsigned long)resume_addr_reg,
155		     sram_virt_base + code_len - 4);
156
157	iounmap(sram_virt_base);
158
159	return 0;
160}
161
162static int __init mvebu_v7_pmsu_init(void)
163{
164	struct device_node *np;
165	struct resource res;
166	int ret = 0;
167
168	np = of_find_matching_node(NULL, of_pmsu_table);
169	if (!np)
170		return 0;
171
172	pr_info("Initializing Power Management Service Unit\n");
173
174	if (of_address_to_resource(np, 0, &res)) {
175		pr_err("unable to get resource\n");
176		ret = -ENOENT;
177		goto out;
178	}
179
180	if (of_device_is_compatible(np, "marvell,armada-370-xp-pmsu")) {
181		pr_warn(FW_WARN "deprecated pmsu binding\n");
182		res.start = res.start - PMSU_BASE_OFFSET;
183		res.end = res.start + PMSU_REG_SIZE - 1;
184	}
185
186	if (!request_mem_region(res.start, resource_size(&res),
187				np->full_name)) {
188		pr_err("unable to request region\n");
189		ret = -EBUSY;
190		goto out;
191	}
192
193	pmsu_mp_phys_base = res.start;
194
195	pmsu_mp_base = ioremap(res.start, resource_size(&res));
196	if (!pmsu_mp_base) {
197		pr_err("unable to map registers\n");
198		release_mem_region(res.start, resource_size(&res));
199		ret = -ENOMEM;
200		goto out;
201	}
202
203 out:
204	of_node_put(np);
205	return ret;
206}
207
208static void mvebu_v7_pmsu_enable_l2_powerdown_onidle(void)
209{
210	u32 reg;
211
212	if (pmsu_mp_base == NULL)
213		return;
214
215	/* Enable L2 & Fabric powerdown in Deep-Idle mode - Fabric */
216	reg = readl(pmsu_mp_base + L2C_NFABRIC_PM_CTL);
217	reg |= L2C_NFABRIC_PM_CTL_PWR_DOWN;
218	writel(reg, pmsu_mp_base + L2C_NFABRIC_PM_CTL);
219}
220
221enum pmsu_idle_prepare_flags {
222	PMSU_PREPARE_NORMAL = 0,
223	PMSU_PREPARE_DEEP_IDLE = BIT(0),
224	PMSU_PREPARE_SNOOP_DISABLE = BIT(1),
225};
226
227/* No locking is needed because we only access per-CPU registers */
228static int mvebu_v7_pmsu_idle_prepare(unsigned long flags)
229{
230	unsigned int hw_cpu = cpu_logical_map(smp_processor_id());
231	u32 reg;
232
233	if (pmsu_mp_base == NULL)
234		return -EINVAL;
235
236	/*
237	 * Adjust the PMSU configuration to wait for WFI signal, enable
238	 * IRQ and FIQ as wakeup events, set wait for snoop queue empty
239	 * indication and mask IRQ and FIQ from CPU
240	 */
241	reg = readl(pmsu_mp_base + PMSU_STATUS_AND_MASK(hw_cpu));
242	reg |= PMSU_STATUS_AND_MASK_CPU_IDLE_WAIT    |
243	       PMSU_STATUS_AND_MASK_IRQ_WAKEUP       |
244	       PMSU_STATUS_AND_MASK_FIQ_WAKEUP       |
245	       PMSU_STATUS_AND_MASK_SNP_Q_EMPTY_WAIT |
246	       PMSU_STATUS_AND_MASK_IRQ_MASK         |
247	       PMSU_STATUS_AND_MASK_FIQ_MASK;
248	writel(reg, pmsu_mp_base + PMSU_STATUS_AND_MASK(hw_cpu));
249
250	reg = readl(pmsu_mp_base + PMSU_CONTROL_AND_CONFIG(hw_cpu));
251	/* ask HW to power down the L2 Cache if needed */
252	if (flags & PMSU_PREPARE_DEEP_IDLE)
253		reg |= PMSU_CONTROL_AND_CONFIG_L2_PWDDN;
254
255	/* request power down */
256	reg |= PMSU_CONTROL_AND_CONFIG_PWDDN_REQ;
257	writel(reg, pmsu_mp_base + PMSU_CONTROL_AND_CONFIG(hw_cpu));
258
259	if (flags & PMSU_PREPARE_SNOOP_DISABLE) {
260		/* Disable snoop disable by HW - SW is taking care of it */
261		reg = readl(pmsu_mp_base + PMSU_CPU_POWER_DOWN_CONTROL(hw_cpu));
262		reg |= PMSU_CPU_POWER_DOWN_DIS_SNP_Q_SKIP;
263		writel(reg, pmsu_mp_base + PMSU_CPU_POWER_DOWN_CONTROL(hw_cpu));
264	}
265
266	return 0;
267}
268
269int armada_370_xp_pmsu_idle_enter(unsigned long deepidle)
270{
271	unsigned long flags = PMSU_PREPARE_SNOOP_DISABLE;
272	int ret;
273
274	if (deepidle)
275		flags |= PMSU_PREPARE_DEEP_IDLE;
276
277	ret = mvebu_v7_pmsu_idle_prepare(flags);
278	if (ret)
279		return ret;
280
281	v7_exit_coherency_flush(all);
282
283	ll_disable_coherency();
284
285	dsb();
286
287	wfi();
288
289	/* If we are here, wfi failed. As processors run out of
290	 * coherency for some time, tlbs might be stale, so flush them
291	 */
292	local_flush_tlb_all();
293
294	ll_enable_coherency();
295
296	/* Test the CR_C bit and set it if it was cleared */
297	asm volatile(
298	"mrc	p15, 0, r0, c1, c0, 0 \n\t"
299	"tst	r0, #(1 << 2) \n\t"
300	"orreq	r0, r0, #(1 << 2) \n\t"
301	"mcreq	p15, 0, r0, c1, c0, 0 \n\t"
302	"isb	"
303	: : : "r0");
304
305	pr_debug("Failed to suspend the system\n");
306
307	return 0;
308}
309
310static int armada_370_xp_cpu_suspend(unsigned long deepidle)
311{
312	return cpu_suspend(deepidle, armada_370_xp_pmsu_idle_enter);
313}
314
315int armada_38x_do_cpu_suspend(unsigned long deepidle)
316{
317	unsigned long flags = 0;
318
319	if (deepidle)
320		flags |= PMSU_PREPARE_DEEP_IDLE;
321
322	mvebu_v7_pmsu_idle_prepare(flags);
323	/*
324	 * Already flushed cache, but do it again as the outer cache
325	 * functions dirty the cache with spinlocks
326	 */
327	v7_exit_coherency_flush(louis);
328
329	scu_power_mode(mvebu_get_scu_base(), SCU_PM_POWEROFF);
330
331	cpu_do_idle();
332
333	return 1;
334}
335
336static int armada_38x_cpu_suspend(unsigned long deepidle)
337{
338	return cpu_suspend(false, armada_38x_do_cpu_suspend);
339}
340
341/* No locking is needed because we only access per-CPU registers */
342void mvebu_v7_pmsu_idle_exit(void)
343{
344	unsigned int hw_cpu = cpu_logical_map(smp_processor_id());
345	u32 reg;
346
347	if (pmsu_mp_base == NULL)
348		return;
349	/* cancel ask HW to power down the L2 Cache if possible */
350	reg = readl(pmsu_mp_base + PMSU_CONTROL_AND_CONFIG(hw_cpu));
351	reg &= ~PMSU_CONTROL_AND_CONFIG_L2_PWDDN;
352	writel(reg, pmsu_mp_base + PMSU_CONTROL_AND_CONFIG(hw_cpu));
353
354	/* cancel Enable wakeup events and mask interrupts */
355	reg = readl(pmsu_mp_base + PMSU_STATUS_AND_MASK(hw_cpu));
356	reg &= ~(PMSU_STATUS_AND_MASK_IRQ_WAKEUP | PMSU_STATUS_AND_MASK_FIQ_WAKEUP);
357	reg &= ~PMSU_STATUS_AND_MASK_CPU_IDLE_WAIT;
358	reg &= ~PMSU_STATUS_AND_MASK_SNP_Q_EMPTY_WAIT;
359	reg &= ~(PMSU_STATUS_AND_MASK_IRQ_MASK | PMSU_STATUS_AND_MASK_FIQ_MASK);
360	writel(reg, pmsu_mp_base + PMSU_STATUS_AND_MASK(hw_cpu));
361}
362
363static int mvebu_v7_cpu_pm_notify(struct notifier_block *self,
364				    unsigned long action, void *hcpu)
365{
366	if (action == CPU_PM_ENTER) {
367		unsigned int hw_cpu = cpu_logical_map(smp_processor_id());
368		mvebu_pmsu_set_cpu_boot_addr(hw_cpu, mvebu_cpu_resume);
369	} else if (action == CPU_PM_EXIT) {
370		mvebu_v7_pmsu_idle_exit();
371	}
372
373	return NOTIFY_OK;
374}
375
376static struct notifier_block mvebu_v7_cpu_pm_notifier = {
377	.notifier_call = mvebu_v7_cpu_pm_notify,
378};
379
380static struct platform_device mvebu_v7_cpuidle_device;
381
382static __init int armada_370_cpuidle_init(void)
383{
384	struct device_node *np;
385	phys_addr_t redirect_reg;
386
387	np = of_find_compatible_node(NULL, NULL, "marvell,coherency-fabric");
388	if (!np)
389		return -ENODEV;
390	of_node_put(np);
391
392	/*
393	 * On Armada 370, there is "a slow exit process from the deep
394	 * idle state due to heavy L1/L2 cache cleanup operations
395	 * performed by the BootROM software". To avoid this, we
396	 * replace the restart code of the bootrom by a a simple jump
397	 * to the boot address. Then the code located at this boot
398	 * address will take care of the initialization.
399	 */
400	redirect_reg = pmsu_mp_phys_base + PMSU_BOOT_ADDR_REDIRECT_OFFSET(0);
401	mvebu_setup_boot_addr_wa(ARMADA_370_CRYPT0_ENG_TARGET,
402				 ARMADA_370_CRYPT0_ENG_ATTR,
403				 redirect_reg);
404
405	mvebu_cpu_resume = armada_370_xp_cpu_resume;
406	mvebu_v7_cpuidle_device.dev.platform_data = armada_370_xp_cpu_suspend;
407	mvebu_v7_cpuidle_device.name = "cpuidle-armada-370";
408
409	return 0;
410}
411
412static __init int armada_38x_cpuidle_init(void)
413{
414	struct device_node *np;
415	void __iomem *mpsoc_base;
416	u32 reg;
417
418	pr_warn("CPU idle is currently broken on Armada 38x: disabling");
419	return 0;
420
421	np = of_find_compatible_node(NULL, NULL,
422				     "marvell,armada-380-coherency-fabric");
423	if (!np)
424		return -ENODEV;
425	of_node_put(np);
426
427	np = of_find_compatible_node(NULL, NULL,
428				     "marvell,armada-380-mpcore-soc-ctrl");
429	if (!np)
430		return -ENODEV;
431	mpsoc_base = of_iomap(np, 0);
432	BUG_ON(!mpsoc_base);
433	of_node_put(np);
434
435	/* Set up reset mask when powering down the cpus */
436	reg = readl(mpsoc_base + MPCORE_RESET_CTL);
437	reg |= MPCORE_RESET_CTL_L2;
438	reg |= MPCORE_RESET_CTL_DEBUG;
439	writel(reg, mpsoc_base + MPCORE_RESET_CTL);
440	iounmap(mpsoc_base);
441
442	/* Set up delay */
443	reg = readl(pmsu_mp_base + PMSU_POWERDOWN_DELAY);
444	reg &= ~PMSU_POWERDOWN_DELAY_MASK;
445	reg |= PMSU_DFLT_ARMADA38X_DELAY;
446	reg |= PMSU_POWERDOWN_DELAY_PMU;
447	writel(reg, pmsu_mp_base + PMSU_POWERDOWN_DELAY);
448
449	mvebu_cpu_resume = armada_38x_cpu_resume;
450	mvebu_v7_cpuidle_device.dev.platform_data = armada_38x_cpu_suspend;
451	mvebu_v7_cpuidle_device.name = "cpuidle-armada-38x";
452
453	return 0;
454}
455
456static __init int armada_xp_cpuidle_init(void)
457{
458	struct device_node *np;
459
460	np = of_find_compatible_node(NULL, NULL, "marvell,coherency-fabric");
461	if (!np)
462		return -ENODEV;
463	of_node_put(np);
464
465	mvebu_cpu_resume = armada_370_xp_cpu_resume;
466	mvebu_v7_cpuidle_device.dev.platform_data = armada_370_xp_cpu_suspend;
467	mvebu_v7_cpuidle_device.name = "cpuidle-armada-xp";
468
469	return 0;
470}
471
472static int __init mvebu_v7_cpu_pm_init(void)
473{
474	struct device_node *np;
475	int ret;
476
477	np = of_find_matching_node(NULL, of_pmsu_table);
478	if (!np)
479		return 0;
480	of_node_put(np);
481
482	/*
483	 * Currently the CPU idle support for Armada 38x is broken, as
484	 * the CPU hotplug uses some of the CPU idle functions it is
485	 * broken too, so let's disable it
486	 */
487	if (of_machine_is_compatible("marvell,armada380")) {
488		cpu_hotplug_disable();
489		pr_warn("CPU hotplug support is currently broken on Armada 38x: disabling");
490	}
491
492	if (of_machine_is_compatible("marvell,armadaxp"))
493		ret = armada_xp_cpuidle_init();
494	else if (of_machine_is_compatible("marvell,armada370"))
495		ret = armada_370_cpuidle_init();
496	else if (of_machine_is_compatible("marvell,armada380"))
497		ret = armada_38x_cpuidle_init();
498	else
499		return 0;
500
501	if (ret)
502		return ret;
503
504	mvebu_v7_pmsu_enable_l2_powerdown_onidle();
505	if (mvebu_v7_cpuidle_device.name)
506		platform_device_register(&mvebu_v7_cpuidle_device);
507	cpu_pm_register_notifier(&mvebu_v7_cpu_pm_notifier);
508
509	return 0;
510}
511
512arch_initcall(mvebu_v7_cpu_pm_init);
513early_initcall(mvebu_v7_pmsu_init);
514
515static void mvebu_pmsu_dfs_request_local(void *data)
516{
517	u32 reg;
518	u32 cpu = smp_processor_id();
519	unsigned long flags;
520
521	local_irq_save(flags);
522
523	/* Prepare to enter idle */
524	reg = readl(pmsu_mp_base + PMSU_STATUS_AND_MASK(cpu));
525	reg |= PMSU_STATUS_AND_MASK_CPU_IDLE_WAIT |
526	       PMSU_STATUS_AND_MASK_IRQ_MASK     |
527	       PMSU_STATUS_AND_MASK_FIQ_MASK;
528	writel(reg, pmsu_mp_base + PMSU_STATUS_AND_MASK(cpu));
529
530	/* Request the DFS transition */
531	reg = readl(pmsu_mp_base + PMSU_CONTROL_AND_CONFIG(cpu));
532	reg |= PMSU_CONTROL_AND_CONFIG_DFS_REQ;
533	writel(reg, pmsu_mp_base + PMSU_CONTROL_AND_CONFIG(cpu));
534
535	/* The fact of entering idle will trigger the DFS transition */
536	wfi();
537
538	/*
539	 * We're back from idle, the DFS transition has completed,
540	 * clear the idle wait indication.
541	 */
542	reg = readl(pmsu_mp_base + PMSU_STATUS_AND_MASK(cpu));
543	reg &= ~PMSU_STATUS_AND_MASK_CPU_IDLE_WAIT;
544	writel(reg, pmsu_mp_base + PMSU_STATUS_AND_MASK(cpu));
545
546	local_irq_restore(flags);
547}
548
549int mvebu_pmsu_dfs_request(int cpu)
550{
551	unsigned long timeout;
552	int hwcpu = cpu_logical_map(cpu);
553	u32 reg;
554
555	/* Clear any previous DFS DONE event */
556	reg = readl(pmsu_mp_base + PMSU_EVENT_STATUS_AND_MASK(hwcpu));
557	reg &= ~PMSU_EVENT_STATUS_AND_MASK_DFS_DONE;
558	writel(reg, pmsu_mp_base + PMSU_EVENT_STATUS_AND_MASK(hwcpu));
559
560	/* Mask the DFS done interrupt, since we are going to poll */
561	reg = readl(pmsu_mp_base + PMSU_EVENT_STATUS_AND_MASK(hwcpu));
562	reg |= PMSU_EVENT_STATUS_AND_MASK_DFS_DONE_MASK;
563	writel(reg, pmsu_mp_base + PMSU_EVENT_STATUS_AND_MASK(hwcpu));
564
565	/* Trigger the DFS on the appropriate CPU */
566	smp_call_function_single(cpu, mvebu_pmsu_dfs_request_local,
567				 NULL, false);
568
569	/* Poll until the DFS done event is generated */
570	timeout = jiffies + HZ;
571	while (time_before(jiffies, timeout)) {
572		reg = readl(pmsu_mp_base + PMSU_EVENT_STATUS_AND_MASK(hwcpu));
573		if (reg & PMSU_EVENT_STATUS_AND_MASK_DFS_DONE)
574			break;
575		udelay(10);
576	}
577
578	if (time_after(jiffies, timeout))
579		return -ETIME;
580
581	/* Restore the DFS mask to its original state */
582	reg = readl(pmsu_mp_base + PMSU_EVENT_STATUS_AND_MASK(hwcpu));
583	reg &= ~PMSU_EVENT_STATUS_AND_MASK_DFS_DONE_MASK;
584	writel(reg, pmsu_mp_base + PMSU_EVENT_STATUS_AND_MASK(hwcpu));
585
586	return 0;
587}
588
589struct cpufreq_dt_platform_data cpufreq_dt_pd = {
590	.independent_clocks = true,
591};
592
593static int __init armada_xp_pmsu_cpufreq_init(void)
594{
595	struct device_node *np;
596	struct resource res;
597	int ret, cpu;
598
599	if (!of_machine_is_compatible("marvell,armadaxp"))
600		return 0;
601
602	/*
603	 * In order to have proper cpufreq handling, we need to ensure
604	 * that the Device Tree description of the CPU clock includes
605	 * the definition of the PMU DFS registers. If not, we do not
606	 * register the clock notifier and the cpufreq driver. This
607	 * piece of code is only for compatibility with old Device
608	 * Trees.
609	 */
610	np = of_find_compatible_node(NULL, NULL, "marvell,armada-xp-cpu-clock");
611	if (!np)
612		return 0;
613
614	ret = of_address_to_resource(np, 1, &res);
615	if (ret) {
616		pr_warn(FW_WARN "not enabling cpufreq, deprecated armada-xp-cpu-clock binding\n");
617		of_node_put(np);
618		return 0;
619	}
620
621	of_node_put(np);
622
623	/*
624	 * For each CPU, this loop registers the operating points
625	 * supported (which are the nominal CPU frequency and half of
626	 * it), and registers the clock notifier that will take care
627	 * of doing the PMSU part of a frequency transition.
628	 */
629	for_each_possible_cpu(cpu) {
630		struct device *cpu_dev;
631		struct clk *clk;
632		int ret;
633
634		cpu_dev = get_cpu_device(cpu);
635		if (!cpu_dev) {
636			pr_err("Cannot get CPU %d\n", cpu);
637			continue;
638		}
639
640		clk = clk_get(cpu_dev, 0);
641		if (IS_ERR(clk)) {
642			pr_err("Cannot get clock for CPU %d\n", cpu);
643			return PTR_ERR(clk);
644		}
645
646		/*
647		 * In case of a failure of dev_pm_opp_add(), we don't
648		 * bother with cleaning up the registered OPP (there's
649		 * no function to do so), and simply cancel the
650		 * registration of the cpufreq device.
651		 */
652		ret = dev_pm_opp_add(cpu_dev, clk_get_rate(clk), 0);
653		if (ret) {
654			clk_put(clk);
655			return ret;
656		}
657
658		ret = dev_pm_opp_add(cpu_dev, clk_get_rate(clk) / 2, 0);
659		if (ret) {
660			clk_put(clk);
661			return ret;
662		}
663	}
664
665	platform_device_register_data(NULL, "cpufreq-dt", -1,
666				      &cpufreq_dt_pd, sizeof(cpufreq_dt_pd));
667	return 0;
668}
669
670device_initcall(armada_xp_pmsu_cpufreq_init);
671