Merge tag 'iommu-updates-v4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/joro...
[firefly-linux-kernel-4.4.55.git] / drivers / soc / dove / pmu.c
1 /*
2  * Marvell Dove PMU support
3  */
4 #include <linux/io.h>
5 #include <linux/irq.h>
6 #include <linux/irqdomain.h>
7 #include <linux/of.h>
8 #include <linux/of_irq.h>
9 #include <linux/of_address.h>
10 #include <linux/platform_device.h>
11 #include <linux/pm_domain.h>
12 #include <linux/reset.h>
13 #include <linux/reset-controller.h>
14 #include <linux/sched.h>
15 #include <linux/slab.h>
16 #include <linux/soc/dove/pmu.h>
17 #include <linux/spinlock.h>
18
19 #define NR_PMU_IRQS             7
20
21 #define PMC_SW_RST              0x30
22 #define PMC_IRQ_CAUSE           0x50
23 #define PMC_IRQ_MASK            0x54
24
25 #define PMU_PWR                 0x10
26 #define PMU_ISO                 0x58
27
28 struct pmu_data {
29         spinlock_t lock;
30         struct device_node *of_node;
31         void __iomem *pmc_base;
32         void __iomem *pmu_base;
33         struct irq_chip_generic *irq_gc;
34         struct irq_domain *irq_domain;
35 #ifdef CONFIG_RESET_CONTROLLER
36         struct reset_controller_dev reset;
37 #endif
38 };
39
40 /*
41  * The PMU contains a register to reset various subsystems within the
42  * SoC.  Export this as a reset controller.
43  */
44 #ifdef CONFIG_RESET_CONTROLLER
45 #define rcdev_to_pmu(rcdev) container_of(rcdev, struct pmu_data, reset)
46
47 static int pmu_reset_reset(struct reset_controller_dev *rc, unsigned long id)
48 {
49         struct pmu_data *pmu = rcdev_to_pmu(rc);
50         unsigned long flags;
51         u32 val;
52
53         spin_lock_irqsave(&pmu->lock, flags);
54         val = readl_relaxed(pmu->pmc_base + PMC_SW_RST);
55         writel_relaxed(val & ~BIT(id), pmu->pmc_base + PMC_SW_RST);
56         writel_relaxed(val | BIT(id), pmu->pmc_base + PMC_SW_RST);
57         spin_unlock_irqrestore(&pmu->lock, flags);
58
59         return 0;
60 }
61
62 static int pmu_reset_assert(struct reset_controller_dev *rc, unsigned long id)
63 {
64         struct pmu_data *pmu = rcdev_to_pmu(rc);
65         unsigned long flags;
66         u32 val = ~BIT(id);
67
68         spin_lock_irqsave(&pmu->lock, flags);
69         val &= readl_relaxed(pmu->pmc_base + PMC_SW_RST);
70         writel_relaxed(val, pmu->pmc_base + PMC_SW_RST);
71         spin_unlock_irqrestore(&pmu->lock, flags);
72
73         return 0;
74 }
75
76 static int pmu_reset_deassert(struct reset_controller_dev *rc, unsigned long id)
77 {
78         struct pmu_data *pmu = rcdev_to_pmu(rc);
79         unsigned long flags;
80         u32 val = BIT(id);
81
82         spin_lock_irqsave(&pmu->lock, flags);
83         val |= readl_relaxed(pmu->pmc_base + PMC_SW_RST);
84         writel_relaxed(val, pmu->pmc_base + PMC_SW_RST);
85         spin_unlock_irqrestore(&pmu->lock, flags);
86
87         return 0;
88 }
89
90 static struct reset_control_ops pmu_reset_ops = {
91         .reset = pmu_reset_reset,
92         .assert = pmu_reset_assert,
93         .deassert = pmu_reset_deassert,
94 };
95
96 static struct reset_controller_dev pmu_reset __initdata = {
97         .ops = &pmu_reset_ops,
98         .owner = THIS_MODULE,
99         .nr_resets = 32,
100 };
101
102 static void __init pmu_reset_init(struct pmu_data *pmu)
103 {
104         int ret;
105
106         pmu->reset = pmu_reset;
107         pmu->reset.of_node = pmu->of_node;
108
109         ret = reset_controller_register(&pmu->reset);
110         if (ret)
111                 pr_err("pmu: %s failed: %d\n", "reset_controller_register", ret);
112 }
113 #else
114 static void __init pmu_reset_init(struct pmu_data *pmu)
115 {
116 }
117 #endif
118
119 struct pmu_domain {
120         struct pmu_data *pmu;
121         u32 pwr_mask;
122         u32 rst_mask;
123         u32 iso_mask;
124         struct generic_pm_domain base;
125 };
126
127 #define to_pmu_domain(dom) container_of(dom, struct pmu_domain, base)
128
129 /*
130  * This deals with the "old" Marvell sequence of bringing a power domain
131  * down/up, which is: apply power, release reset, disable isolators.
132  *
133  * Later devices apparantly use a different sequence: power up, disable
134  * isolators, assert repair signal, enable SRMA clock, enable AXI clock,
135  * enable module clock, deassert reset.
136  *
137  * Note: reading the assembly, it seems that the IO accessors have an
138  * unfortunate side-effect - they cause memory already read into registers
139  * for the if () to be re-read for the bit-set or bit-clear operation.
140  * The code is written to avoid this.
141  */
142 static int pmu_domain_power_off(struct generic_pm_domain *domain)
143 {
144         struct pmu_domain *pmu_dom = to_pmu_domain(domain);
145         struct pmu_data *pmu = pmu_dom->pmu;
146         unsigned long flags;
147         unsigned int val;
148         void __iomem *pmu_base = pmu->pmu_base;
149         void __iomem *pmc_base = pmu->pmc_base;
150
151         spin_lock_irqsave(&pmu->lock, flags);
152
153         /* Enable isolators */
154         if (pmu_dom->iso_mask) {
155                 val = ~pmu_dom->iso_mask;
156                 val &= readl_relaxed(pmu_base + PMU_ISO);
157                 writel_relaxed(val, pmu_base + PMU_ISO);
158         }
159
160         /* Reset unit */
161         if (pmu_dom->rst_mask) {
162                 val = ~pmu_dom->rst_mask;
163                 val &= readl_relaxed(pmc_base + PMC_SW_RST);
164                 writel_relaxed(val, pmc_base + PMC_SW_RST);
165         }
166
167         /* Power down */
168         val = readl_relaxed(pmu_base + PMU_PWR) | pmu_dom->pwr_mask;
169         writel_relaxed(val, pmu_base + PMU_PWR);
170
171         spin_unlock_irqrestore(&pmu->lock, flags);
172
173         return 0;
174 }
175
176 static int pmu_domain_power_on(struct generic_pm_domain *domain)
177 {
178         struct pmu_domain *pmu_dom = to_pmu_domain(domain);
179         struct pmu_data *pmu = pmu_dom->pmu;
180         unsigned long flags;
181         unsigned int val;
182         void __iomem *pmu_base = pmu->pmu_base;
183         void __iomem *pmc_base = pmu->pmc_base;
184
185         spin_lock_irqsave(&pmu->lock, flags);
186
187         /* Power on */
188         val = ~pmu_dom->pwr_mask & readl_relaxed(pmu_base + PMU_PWR);
189         writel_relaxed(val, pmu_base + PMU_PWR);
190
191         /* Release reset */
192         if (pmu_dom->rst_mask) {
193                 val = pmu_dom->rst_mask;
194                 val |= readl_relaxed(pmc_base + PMC_SW_RST);
195                 writel_relaxed(val, pmc_base + PMC_SW_RST);
196         }
197
198         /* Disable isolators */
199         if (pmu_dom->iso_mask) {
200                 val = pmu_dom->iso_mask;
201                 val |= readl_relaxed(pmu_base + PMU_ISO);
202                 writel_relaxed(val, pmu_base + PMU_ISO);
203         }
204
205         spin_unlock_irqrestore(&pmu->lock, flags);
206
207         return 0;
208 }
209
210 static void __pmu_domain_register(struct pmu_domain *domain,
211         struct device_node *np)
212 {
213         unsigned int val = readl_relaxed(domain->pmu->pmu_base + PMU_PWR);
214
215         domain->base.power_off = pmu_domain_power_off;
216         domain->base.power_on = pmu_domain_power_on;
217
218         pm_genpd_init(&domain->base, NULL, !(val & domain->pwr_mask));
219
220         if (np)
221                 of_genpd_add_provider_simple(np, &domain->base);
222 }
223
224 /* PMU IRQ controller */
225 static void pmu_irq_handler(struct irq_desc *desc)
226 {
227         struct pmu_data *pmu = irq_desc_get_handler_data(desc);
228         struct irq_chip_generic *gc = pmu->irq_gc;
229         struct irq_domain *domain = pmu->irq_domain;
230         void __iomem *base = gc->reg_base;
231         u32 stat = readl_relaxed(base + PMC_IRQ_CAUSE) & gc->mask_cache;
232         u32 done = ~0;
233
234         if (stat == 0) {
235                 handle_bad_irq(desc);
236                 return;
237         }
238
239         while (stat) {
240                 u32 hwirq = fls(stat) - 1;
241
242                 stat &= ~(1 << hwirq);
243                 done &= ~(1 << hwirq);
244
245                 generic_handle_irq(irq_find_mapping(domain, hwirq));
246         }
247
248         /*
249          * The PMU mask register is not RW0C: it is RW.  This means that
250          * the bits take whatever value is written to them; if you write
251          * a '1', you will set the interrupt.
252          *
253          * Unfortunately this means there is NO race free way to clear
254          * these interrupts.
255          *
256          * So, let's structure the code so that the window is as small as
257          * possible.
258          */
259         irq_gc_lock(gc);
260         done &= readl_relaxed(base + PMC_IRQ_CAUSE);
261         writel_relaxed(done, base + PMC_IRQ_CAUSE);
262         irq_gc_unlock(gc);
263 }
264
265 static int __init dove_init_pmu_irq(struct pmu_data *pmu, int irq)
266 {
267         const char *name = "pmu_irq";
268         struct irq_chip_generic *gc;
269         struct irq_domain *domain;
270         int ret;
271
272         /* mask and clear all interrupts */
273         writel(0, pmu->pmc_base + PMC_IRQ_MASK);
274         writel(0, pmu->pmc_base + PMC_IRQ_CAUSE);
275
276         domain = irq_domain_add_linear(pmu->of_node, NR_PMU_IRQS,
277                                        &irq_generic_chip_ops, NULL);
278         if (!domain) {
279                 pr_err("%s: unable to add irq domain\n", name);
280                 return -ENOMEM;
281         }
282
283         ret = irq_alloc_domain_generic_chips(domain, NR_PMU_IRQS, 1, name,
284                                              handle_level_irq,
285                                              IRQ_NOREQUEST | IRQ_NOPROBE, 0,
286                                              IRQ_GC_INIT_MASK_CACHE);
287         if (ret) {
288                 pr_err("%s: unable to alloc irq domain gc: %d\n", name, ret);
289                 irq_domain_remove(domain);
290                 return ret;
291         }
292
293         gc = irq_get_domain_generic_chip(domain, 0);
294         gc->reg_base = pmu->pmc_base;
295         gc->chip_types[0].regs.mask = PMC_IRQ_MASK;
296         gc->chip_types[0].chip.irq_mask = irq_gc_mask_clr_bit;
297         gc->chip_types[0].chip.irq_unmask = irq_gc_mask_set_bit;
298
299         pmu->irq_domain = domain;
300         pmu->irq_gc = gc;
301
302         irq_set_handler_data(irq, pmu);
303         irq_set_chained_handler(irq, pmu_irq_handler);
304
305         return 0;
306 }
307
308 /*
309  * pmu: power-manager@d0000 {
310  *      compatible = "marvell,dove-pmu";
311  *      reg = <0xd0000 0x8000> <0xd8000 0x8000>;
312  *      interrupts = <33>;
313  *      interrupt-controller;
314  *      #reset-cells = 1;
315  *      vpu_domain: vpu-domain {
316  *              #power-domain-cells = <0>;
317  *              marvell,pmu_pwr_mask = <0x00000008>;
318  *              marvell,pmu_iso_mask = <0x00000001>;
319  *              resets = <&pmu 16>;
320  *      };
321  *      gpu_domain: gpu-domain {
322  *              #power-domain-cells = <0>;
323  *              marvell,pmu_pwr_mask = <0x00000004>;
324  *              marvell,pmu_iso_mask = <0x00000002>;
325  *              resets = <&pmu 18>;
326  *      };
327  * };
328  */
329 int __init dove_init_pmu(void)
330 {
331         struct device_node *np_pmu, *domains_node, *np;
332         struct pmu_data *pmu;
333         int ret, parent_irq;
334
335         /* Lookup the PMU node */
336         np_pmu = of_find_compatible_node(NULL, NULL, "marvell,dove-pmu");
337         if (!np_pmu)
338                 return 0;
339
340         domains_node = of_get_child_by_name(np_pmu, "domains");
341         if (!domains_node) {
342                 pr_err("%s: failed to find domains sub-node\n", np_pmu->name);
343                 return 0;
344         }
345
346         pmu = kzalloc(sizeof(*pmu), GFP_KERNEL);
347         if (!pmu)
348                 return -ENOMEM;
349
350         spin_lock_init(&pmu->lock);
351         pmu->of_node = np_pmu;
352         pmu->pmc_base = of_iomap(pmu->of_node, 0);
353         pmu->pmu_base = of_iomap(pmu->of_node, 1);
354         if (!pmu->pmc_base || !pmu->pmu_base) {
355                 pr_err("%s: failed to map PMU\n", np_pmu->name);
356                 iounmap(pmu->pmu_base);
357                 iounmap(pmu->pmc_base);
358                 kfree(pmu);
359                 return -ENOMEM;
360         }
361
362         pmu_reset_init(pmu);
363
364         for_each_available_child_of_node(domains_node, np) {
365                 struct of_phandle_args args;
366                 struct pmu_domain *domain;
367
368                 domain = kzalloc(sizeof(*domain), GFP_KERNEL);
369                 if (!domain)
370                         break;
371
372                 domain->pmu = pmu;
373                 domain->base.name = kstrdup(np->name, GFP_KERNEL);
374                 if (!domain->base.name) {
375                         kfree(domain);
376                         break;
377                 }
378
379                 of_property_read_u32(np, "marvell,pmu_pwr_mask",
380                                      &domain->pwr_mask);
381                 of_property_read_u32(np, "marvell,pmu_iso_mask",
382                                      &domain->iso_mask);
383
384                 /*
385                  * We parse the reset controller property directly here
386                  * to ensure that we can operate when the reset controller
387                  * support is not configured into the kernel.
388                  */
389                 ret = of_parse_phandle_with_args(np, "resets", "#reset-cells",
390                                                  0, &args);
391                 if (ret == 0) {
392                         if (args.np == pmu->of_node)
393                                 domain->rst_mask = BIT(args.args[0]);
394                         of_node_put(args.np);
395                 }
396
397                 __pmu_domain_register(domain, np);
398         }
399
400         /* Loss of the interrupt controller is not a fatal error. */
401         parent_irq = irq_of_parse_and_map(pmu->of_node, 0);
402         if (!parent_irq) {
403                 pr_err("%s: no interrupt specified\n", np_pmu->name);
404         } else {
405                 ret = dove_init_pmu_irq(pmu, parent_irq);
406                 if (ret)
407                         pr_err("dove_init_pmu_irq() failed: %d\n", ret);
408         }
409
410         return 0;
411 }