1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Renesas R-Car V3U System Controller
4 *
5 * Copyright (C) 2020 Renesas Electronics Corp.
6 */
7
8#include <linux/bits.h>
9#include <linux/clk/renesas.h>
10#include <linux/delay.h>
11#include <linux/err.h>
12#include <linux/io.h>
13#include <linux/iopoll.h>
14#include <linux/kernel.h>
15#include <linux/mm.h>
16#include <linux/of_address.h>
17#include <linux/pm_domain.h>
18#include <linux/slab.h>
19#include <linux/spinlock.h>
20#include <linux/types.h>
21
22#include <dt-bindings/power/r8a779a0-sysc.h>
23
24/*
25 * Power Domain flags
26 */
27#define PD_CPU		BIT(0)	/* Area contains main CPU core */
28#define PD_SCU		BIT(1)	/* Area contains SCU and L2 cache */
29#define PD_NO_CR	BIT(2)	/* Area lacks PWR{ON,OFF}CR registers */
30
31#define PD_CPU_NOCR	PD_CPU | PD_NO_CR /* CPU area lacks CR */
32#define PD_ALWAYS_ON	PD_NO_CR	  /* Always-on area */
33
34/*
35 * Description of a Power Area
36 */
37struct r8a779a0_sysc_area {
38	const char *name;
39	u8 pdr;			/* PDRn */
40	int parent;		/* -1 if none */
41	unsigned int flags;	/* See PD_* */
42};
43
44/*
45 * SoC-specific Power Area Description
46 */
47struct r8a779a0_sysc_info {
48	const struct r8a779a0_sysc_area *areas;
49	unsigned int num_areas;
50};
51
52static struct r8a779a0_sysc_area r8a779a0_areas[] __initdata = {
53	{ "always-on",	R8A779A0_PD_ALWAYS_ON, -1, PD_ALWAYS_ON },
54	{ "a3e0",	R8A779A0_PD_A3E0, R8A779A0_PD_ALWAYS_ON, PD_SCU },
55	{ "a3e1",	R8A779A0_PD_A3E1, R8A779A0_PD_ALWAYS_ON, PD_SCU },
56	{ "a2e0d0",	R8A779A0_PD_A2E0D0, R8A779A0_PD_A3E0, PD_SCU },
57	{ "a2e0d1",	R8A779A0_PD_A2E0D1, R8A779A0_PD_A3E0, PD_SCU },
58	{ "a2e1d0",	R8A779A0_PD_A2E1D0, R8A779A0_PD_A3E1, PD_SCU },
59	{ "a2e1d1",	R8A779A0_PD_A2E1D1, R8A779A0_PD_A3E1, PD_SCU },
60	{ "a1e0d0c0",	R8A779A0_PD_A1E0D0C0, R8A779A0_PD_A2E0D0, PD_CPU_NOCR },
61	{ "a1e0d0c1",	R8A779A0_PD_A1E0D0C1, R8A779A0_PD_A2E0D0, PD_CPU_NOCR },
62	{ "a1e0d1c0",	R8A779A0_PD_A1E0D1C0, R8A779A0_PD_A2E0D1, PD_CPU_NOCR },
63	{ "a1e0d1c1",	R8A779A0_PD_A1E0D1C1, R8A779A0_PD_A2E0D1, PD_CPU_NOCR },
64	{ "a1e1d0c0",	R8A779A0_PD_A1E1D0C0, R8A779A0_PD_A2E1D0, PD_CPU_NOCR },
65	{ "a1e1d0c1",	R8A779A0_PD_A1E1D0C1, R8A779A0_PD_A2E1D0, PD_CPU_NOCR },
66	{ "a1e1d1c0",	R8A779A0_PD_A1E1D1C0, R8A779A0_PD_A2E1D1, PD_CPU_NOCR },
67	{ "a1e1d1c1",	R8A779A0_PD_A1E1D1C1, R8A779A0_PD_A2E1D1, PD_CPU_NOCR },
68	{ "3dg-a",	R8A779A0_PD_3DG_A, R8A779A0_PD_ALWAYS_ON },
69	{ "3dg-b",	R8A779A0_PD_3DG_B, R8A779A0_PD_3DG_A },
70	{ "a3vip0",	R8A779A0_PD_A3VIP0, R8A779A0_PD_ALWAYS_ON },
71	{ "a3vip1",	R8A779A0_PD_A3VIP1, R8A779A0_PD_ALWAYS_ON },
72	{ "a3vip3",	R8A779A0_PD_A3VIP3, R8A779A0_PD_ALWAYS_ON },
73	{ "a3vip2",	R8A779A0_PD_A3VIP2, R8A779A0_PD_ALWAYS_ON },
74	{ "a3isp01",	R8A779A0_PD_A3ISP01, R8A779A0_PD_ALWAYS_ON },
75	{ "a3isp23",	R8A779A0_PD_A3ISP23, R8A779A0_PD_ALWAYS_ON },
76	{ "a3ir",	R8A779A0_PD_A3IR, R8A779A0_PD_ALWAYS_ON },
77	{ "a2cn0",	R8A779A0_PD_A2CN0, R8A779A0_PD_A3IR },
78	{ "a2imp01",	R8A779A0_PD_A2IMP01, R8A779A0_PD_A3IR },
79	{ "a2dp0",	R8A779A0_PD_A2DP0, R8A779A0_PD_A3IR },
80	{ "a2cv0",	R8A779A0_PD_A2CV0, R8A779A0_PD_A3IR },
81	{ "a2cv1",	R8A779A0_PD_A2CV1, R8A779A0_PD_A3IR },
82	{ "a2cv4",	R8A779A0_PD_A2CV4, R8A779A0_PD_A3IR },
83	{ "a2cv6",	R8A779A0_PD_A2CV6, R8A779A0_PD_A3IR },
84	{ "a2cn2",	R8A779A0_PD_A2CN2, R8A779A0_PD_A3IR },
85	{ "a2imp23",	R8A779A0_PD_A2IMP23, R8A779A0_PD_A3IR },
86	{ "a2dp1",	R8A779A0_PD_A2DP1, R8A779A0_PD_A3IR },
87	{ "a2cv2",	R8A779A0_PD_A2CV2, R8A779A0_PD_A3IR },
88	{ "a2cv3",	R8A779A0_PD_A2CV3, R8A779A0_PD_A3IR },
89	{ "a2cv5",	R8A779A0_PD_A2CV5, R8A779A0_PD_A3IR },
90	{ "a2cv7",	R8A779A0_PD_A2CV7, R8A779A0_PD_A3IR },
91	{ "a2cn1",	R8A779A0_PD_A2CN1, R8A779A0_PD_A3IR },
92	{ "a1cnn0",	R8A779A0_PD_A1CNN0, R8A779A0_PD_A2CN0 },
93	{ "a1cnn2",	R8A779A0_PD_A1CNN2, R8A779A0_PD_A2CN2 },
94	{ "a1dsp0",	R8A779A0_PD_A1DSP0, R8A779A0_PD_A2CN2 },
95	{ "a1cnn1",	R8A779A0_PD_A1CNN1, R8A779A0_PD_A2CN1 },
96	{ "a1dsp1",	R8A779A0_PD_A1DSP1, R8A779A0_PD_A2CN1 },
97};
98
99static const struct r8a779a0_sysc_info r8a779a0_sysc_info __initconst = {
100	.areas = r8a779a0_areas,
101	.num_areas = ARRAY_SIZE(r8a779a0_areas),
102};
103
104/* SYSC Common */
105#define SYSCSR		0x000	/* SYSC Status Register */
106#define SYSCPONSR(x)	(0x800 + ((x) * 0x4)) /* Power-ON Status Register 0 */
107#define SYSCPOFFSR(x)	(0x808 + ((x) * 0x4)) /* Power-OFF Status Register */
108#define SYSCISCR(x)	(0x810 + ((x) * 0x4)) /* Interrupt Status/Clear Register */
109#define SYSCIER(x)	(0x820 + ((x) * 0x4)) /* Interrupt Enable Register */
110#define SYSCIMR(x)	(0x830 + ((x) * 0x4)) /* Interrupt Mask Register */
111
112/* Power Domain Registers */
113#define PDRSR(n)	(0x1000 + ((n) * 0x40))
114#define PDRONCR(n)	(0x1004 + ((n) * 0x40))
115#define PDROFFCR(n)	(0x1008 + ((n) * 0x40))
116#define PDRESR(n)	(0x100C + ((n) * 0x40))
117
118/* PWRON/PWROFF */
119#define PWRON_PWROFF		BIT(0)	/* Power-ON/OFF request */
120
121/* PDRESR */
122#define PDRESR_ERR		BIT(0)
123
124/* PDRSR */
125#define PDRSR_OFF		BIT(0)	/* Power-OFF state */
126#define PDRSR_ON		BIT(4)	/* Power-ON state */
127#define PDRSR_OFF_STATE		BIT(8)  /* Processing Power-OFF sequence */
128#define PDRSR_ON_STATE		BIT(12) /* Processing Power-ON sequence */
129
130#define SYSCSR_BUSY		GENMASK(1, 0)	/* All bit sets is not busy */
131
132#define SYSCSR_TIMEOUT		10000
133#define SYSCSR_DELAY_US		10
134
135#define PDRESR_RETRIES		1000
136#define PDRESR_DELAY_US		10
137
138#define SYSCISR_TIMEOUT		10000
139#define SYSCISR_DELAY_US	10
140
141#define NUM_DOMAINS_EACH_REG	BITS_PER_TYPE(u32)
142
143static void __iomem *r8a779a0_sysc_base;
144static DEFINE_SPINLOCK(r8a779a0_sysc_lock); /* SMP CPUs + I/O devices */
145
146static int r8a779a0_sysc_pwr_on_off(u8 pdr, bool on)
147{
148	unsigned int reg_offs;
149	u32 val;
150	int ret;
151
152	if (on)
153		reg_offs = PDRONCR(pdr);
154	else
155		reg_offs = PDROFFCR(pdr);
156
157	/* Wait until SYSC is ready to accept a power request */
158	ret = readl_poll_timeout_atomic(r8a779a0_sysc_base + SYSCSR, val,
159					(val & SYSCSR_BUSY) == SYSCSR_BUSY,
160					SYSCSR_DELAY_US, SYSCSR_TIMEOUT);
161	if (ret < 0)
162		return -EAGAIN;
163
164	/* Submit power shutoff or power resume request */
165	iowrite32(PWRON_PWROFF, r8a779a0_sysc_base + reg_offs);
166
167	return 0;
168}
169
170static int clear_irq_flags(unsigned int reg_idx, unsigned int isr_mask)
171{
172	u32 val;
173	int ret;
174
175	iowrite32(isr_mask, r8a779a0_sysc_base + SYSCISCR(reg_idx));
176
177	ret = readl_poll_timeout_atomic(r8a779a0_sysc_base + SYSCISCR(reg_idx),
178					val, !(val & isr_mask),
179					SYSCISR_DELAY_US, SYSCISR_TIMEOUT);
180	if (ret < 0) {
181		pr_err("\n %s : Can not clear IRQ flags in SYSCISCR", __func__);
182		return -EIO;
183	}
184
185	return 0;
186}
187
188static int r8a779a0_sysc_power(u8 pdr, bool on)
189{
190	unsigned int isr_mask;
191	unsigned int reg_idx, bit_idx;
192	unsigned int status;
193	unsigned long flags;
194	int ret = 0;
195	u32 val;
196	int k;
197
198	spin_lock_irqsave(&r8a779a0_sysc_lock, flags);
199
200	reg_idx = pdr / NUM_DOMAINS_EACH_REG;
201	bit_idx = pdr % NUM_DOMAINS_EACH_REG;
202
203	isr_mask = BIT(bit_idx);
204
205	/*
206	 * The interrupt source needs to be enabled, but masked, to prevent the
207	 * CPU from receiving it.
208	 */
209	iowrite32(ioread32(r8a779a0_sysc_base + SYSCIER(reg_idx)) | isr_mask,
210		  r8a779a0_sysc_base + SYSCIER(reg_idx));
211	iowrite32(ioread32(r8a779a0_sysc_base + SYSCIMR(reg_idx)) | isr_mask,
212		  r8a779a0_sysc_base + SYSCIMR(reg_idx));
213
214	ret = clear_irq_flags(reg_idx, isr_mask);
215	if (ret)
216		goto out;
217
218	/* Submit power shutoff or resume request until it was accepted */
219	for (k = 0; k < PDRESR_RETRIES; k++) {
220		ret = r8a779a0_sysc_pwr_on_off(pdr, on);
221		if (ret)
222			goto out;
223
224		status = ioread32(r8a779a0_sysc_base + PDRESR(pdr));
225		if (!(status & PDRESR_ERR))
226			break;
227
228		udelay(PDRESR_DELAY_US);
229	}
230
231	if (k == PDRESR_RETRIES) {
232		ret = -EIO;
233		goto out;
234	}
235
236	/* Wait until the power shutoff or resume request has completed * */
237	ret = readl_poll_timeout_atomic(r8a779a0_sysc_base + SYSCISCR(reg_idx),
238					val, (val & isr_mask),
239					SYSCISR_DELAY_US, SYSCISR_TIMEOUT);
240	if (ret < 0) {
241		ret = -EIO;
242		goto out;
243	}
244
245	/* Clear interrupt flags */
246	ret = clear_irq_flags(reg_idx, isr_mask);
247	if (ret)
248		goto out;
249
250 out:
251	spin_unlock_irqrestore(&r8a779a0_sysc_lock, flags);
252
253	pr_debug("sysc power %s domain %d: %08x -> %d\n", on ? "on" : "off",
254		 pdr, ioread32(r8a779a0_sysc_base + SYSCISCR(reg_idx)), ret);
255	return ret;
256}
257
258static bool r8a779a0_sysc_power_is_off(u8 pdr)
259{
260	unsigned int st;
261
262	st = ioread32(r8a779a0_sysc_base + PDRSR(pdr));
263
264	if (st & PDRSR_OFF)
265		return true;
266
267	return false;
268}
269
270struct r8a779a0_sysc_pd {
271	struct generic_pm_domain genpd;
272	u8 pdr;
273	unsigned int flags;
274	char name[];
275};
276
277static inline struct r8a779a0_sysc_pd *to_r8a779a0_pd(struct generic_pm_domain *d)
278{
279	return container_of(d, struct r8a779a0_sysc_pd, genpd);
280}
281
282static int r8a779a0_sysc_pd_power_off(struct generic_pm_domain *genpd)
283{
284	struct r8a779a0_sysc_pd *pd = to_r8a779a0_pd(genpd);
285
286	pr_debug("%s: %s\n", __func__, genpd->name);
287	return r8a779a0_sysc_power(pd->pdr, false);
288}
289
290static int r8a779a0_sysc_pd_power_on(struct generic_pm_domain *genpd)
291{
292	struct r8a779a0_sysc_pd *pd = to_r8a779a0_pd(genpd);
293
294	pr_debug("%s: %s\n", __func__, genpd->name);
295	return r8a779a0_sysc_power(pd->pdr, true);
296}
297
298static int __init r8a779a0_sysc_pd_setup(struct r8a779a0_sysc_pd *pd)
299{
300	struct generic_pm_domain *genpd = &pd->genpd;
301	const char *name = pd->genpd.name;
302	int error;
303
304	if (pd->flags & PD_CPU) {
305		/*
306		 * This domain contains a CPU core and therefore it should
307		 * only be turned off if the CPU is not in use.
308		 */
309		pr_debug("PM domain %s contains %s\n", name, "CPU");
310		genpd->flags |= GENPD_FLAG_ALWAYS_ON;
311	} else if (pd->flags & PD_SCU) {
312		/*
313		 * This domain contains an SCU and cache-controller, and
314		 * therefore it should only be turned off if the CPU cores are
315		 * not in use.
316		 */
317		pr_debug("PM domain %s contains %s\n", name, "SCU");
318		genpd->flags |= GENPD_FLAG_ALWAYS_ON;
319	} else if (pd->flags & PD_NO_CR) {
320		/*
321		 * This domain cannot be turned off.
322		 */
323		genpd->flags |= GENPD_FLAG_ALWAYS_ON;
324	}
325
326	if (!(pd->flags & (PD_CPU | PD_SCU))) {
327		/* Enable Clock Domain for I/O devices */
328		genpd->flags |= GENPD_FLAG_PM_CLK | GENPD_FLAG_ACTIVE_WAKEUP;
329		genpd->attach_dev = cpg_mssr_attach_dev;
330		genpd->detach_dev = cpg_mssr_detach_dev;
331	}
332
333	genpd->power_off = r8a779a0_sysc_pd_power_off;
334	genpd->power_on = r8a779a0_sysc_pd_power_on;
335
336	if (pd->flags & (PD_CPU | PD_NO_CR)) {
337		/* Skip CPUs (handled by SMP code) and areas without control */
338		pr_debug("%s: Not touching %s\n", __func__, genpd->name);
339		goto finalize;
340	}
341
342	if (!r8a779a0_sysc_power_is_off(pd->pdr)) {
343		pr_debug("%s: %s is already powered\n", __func__, genpd->name);
344		goto finalize;
345	}
346
347	r8a779a0_sysc_power(pd->pdr, true);
348
349finalize:
350	error = pm_genpd_init(genpd, &simple_qos_governor, false);
351	if (error)
352		pr_err("Failed to init PM domain %s: %d\n", name, error);
353
354	return error;
355}
356
357static const struct of_device_id r8a779a0_sysc_matches[] __initconst = {
358	{ .compatible = "renesas,r8a779a0-sysc", .data = &r8a779a0_sysc_info },
359	{ /* sentinel */ }
360};
361
362struct r8a779a0_pm_domains {
363	struct genpd_onecell_data onecell_data;
364	struct generic_pm_domain *domains[R8A779A0_PD_ALWAYS_ON + 1];
365};
366
367static struct genpd_onecell_data *r8a779a0_sysc_onecell_data;
368
369static int __init r8a779a0_sysc_pd_init(void)
370{
371	const struct r8a779a0_sysc_info *info;
372	const struct of_device_id *match;
373	struct r8a779a0_pm_domains *domains;
374	struct device_node *np;
375	void __iomem *base;
376	unsigned int i;
377	int error;
378
379	np = of_find_matching_node_and_match(NULL, r8a779a0_sysc_matches, &match);
380	if (!np)
381		return -ENODEV;
382
383	info = match->data;
384
385	base = of_iomap(np, 0);
386	if (!base) {
387		pr_warn("%pOF: Cannot map regs\n", np);
388		error = -ENOMEM;
389		goto out_put;
390	}
391
392	r8a779a0_sysc_base = base;
393
394	domains = kzalloc(sizeof(*domains), GFP_KERNEL);
395	if (!domains) {
396		error = -ENOMEM;
397		goto out_put;
398	}
399
400	domains->onecell_data.domains = domains->domains;
401	domains->onecell_data.num_domains = ARRAY_SIZE(domains->domains);
402	r8a779a0_sysc_onecell_data = &domains->onecell_data;
403
404	for (i = 0; i < info->num_areas; i++) {
405		const struct r8a779a0_sysc_area *area = &info->areas[i];
406		struct r8a779a0_sysc_pd *pd;
407
408		if (!area->name) {
409			/* Skip NULLified area */
410			continue;
411		}
412
413		pd = kzalloc(sizeof(*pd) + strlen(area->name) + 1, GFP_KERNEL);
414		if (!pd) {
415			error = -ENOMEM;
416			goto out_put;
417		}
418
419		strcpy(pd->name, area->name);
420		pd->genpd.name = pd->name;
421		pd->pdr = area->pdr;
422		pd->flags = area->flags;
423
424		error = r8a779a0_sysc_pd_setup(pd);
425		if (error)
426			goto out_put;
427
428		domains->domains[area->pdr] = &pd->genpd;
429
430		if (area->parent < 0)
431			continue;
432
433		error = pm_genpd_add_subdomain(domains->domains[area->parent],
434					       &pd->genpd);
435		if (error) {
436			pr_warn("Failed to add PM subdomain %s to parent %u\n",
437				area->name, area->parent);
438			goto out_put;
439		}
440	}
441
442	error = of_genpd_add_provider_onecell(np, &domains->onecell_data);
443
444out_put:
445	of_node_put(np);
446	return error;
447}
448early_initcall(r8a779a0_sysc_pd_init);
449