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 }