arch/arm/mach-omap2/omap-wakeupgen.c

   1 /*
   2  * OMAP WakeupGen Source file
   3  *
   4  * OMAP WakeupGen is the interrupt controller extension used along
   5  * with ARM GIC to wake the CPU out from low power states on
   6  * external interrupts. It is responsible for generating wakeup
   7  * event from the incoming interrupts and enable bits. It is
   8  * implemented in MPU always ON power domain. During normal operation,
   9  * WakeupGen delivers external interrupts directly to the GIC.
  10  *
  11  * Copyright (C) 2011 Texas Instruments, Inc.
  12  *      Santosh Shilimkar <santosh.shilimkar@ti.com>
  13  *
  14  * This program is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU General Public License version 2 as
  16  * published by the Free Software Foundation.
  17  */
  18
  19 #include <linux/kernel.h>
  20 #include <linux/init.h>
  21 #include <linux/io.h>
  22 #include <linux/irq.h>
  23 #include <linux/platform_device.h>
  24 #include <linux/cpu.h>
  25 #include <linux/notifier.h>
  26 #include <linux/cpu_pm.h>
  27 #include <linux/irqchip/arm-gic.h>
  28
  29 #include "omap-wakeupgen.h"
  30 #include "omap-secure.h"
  31
  32 #include "soc.h"
  33 #include "omap4-sar-layout.h"
  34 #include "common.h"
  35
  36 #define AM43XX_NR_REG_BANKS     7
  37 #define AM43XX_IRQS             224
  38 #define MAX_NR_REG_BANKS        AM43XX_NR_REG_BANKS
  39 #define MAX_IRQS                AM43XX_IRQS
  40 #define DEFAULT_NR_REG_BANKS    5
  41 #define DEFAULT_IRQS            160
  42 #define WKG_MASK_ALL            0x00000000
  43 #define WKG_UNMASK_ALL          0xffffffff
  44 #define CPU_ENA_OFFSET          0x400
  45 #define CPU0_ID                 0x0
  46 #define CPU1_ID                 0x1
  47 #define OMAP4_NR_BANKS          4
  48 #define OMAP4_NR_IRQS           128
  49
  50 static void __iomem *wakeupgen_base;
  51 static void __iomem *sar_base;
  52 static DEFINE_RAW_SPINLOCK(wakeupgen_lock);
  53 static unsigned int irq_target_cpu[MAX_IRQS];
  54 static unsigned int irq_banks = DEFAULT_NR_REG_BANKS;
  55 static unsigned int max_irqs = DEFAULT_IRQS;
  56 static unsigned int omap_secure_apis;
  57
  58 /*
  59  * Static helper functions.
  60  */
  61 static inline u32 wakeupgen_readl(u8 idx, u32 cpu)
  62 {
  63         return readl_relaxed(wakeupgen_base + OMAP_WKG_ENB_A_0 +
  64                                 (cpu * CPU_ENA_OFFSET) + (idx * 4));
  65 }
  66
  67 static inline void wakeupgen_writel(u32 val, u8 idx, u32 cpu)
  68 {
  69         writel_relaxed(val, wakeupgen_base + OMAP_WKG_ENB_A_0 +
  70                                 (cpu * CPU_ENA_OFFSET) + (idx * 4));
  71 }
  72
  73 static inline void sar_writel(u32 val, u32 offset, u8 idx)
  74 {
  75         writel_relaxed(val, sar_base + offset + (idx * 4));
  76 }
  77
  78 static inline int _wakeupgen_get_irq_info(u32 irq, u32 *bit_posn, u8 *reg_index)
  79 {
  80         unsigned int spi_irq;
  81
  82         /*
  83          * PPIs and SGIs are not supported.
  84          */
  85         if (irq < OMAP44XX_IRQ_GIC_START)
  86                 return -EINVAL;
  87
  88         /*
  89          * Subtract the GIC offset.
  90          */
  91         spi_irq = irq - OMAP44XX_IRQ_GIC_START;
  92         if (spi_irq > MAX_IRQS) {
  93                 pr_err("omap wakeupGen: Invalid IRQ%d\n", irq);
  94                 return -EINVAL;
  95         }
  96
  97         /*
  98          * Each WakeupGen register controls 32 interrupt.
  99          * i.e. 1 bit per SPI IRQ
 100          */
 101         *reg_index = spi_irq >> 5;
 102         *bit_posn = spi_irq %= 32;
 103
 104         return 0;
 105 }
 106
 107 static void _wakeupgen_clear(unsigned int irq, unsigned int cpu)
 108 {
 109         u32 val, bit_number;
 110         u8 i;
 111
 112         if (_wakeupgen_get_irq_info(irq, &bit_number, &i))
 113                 return;
 114
 115         val = wakeupgen_readl(i, cpu);
 116         val &= ~BIT(bit_number);
 117         wakeupgen_writel(val, i, cpu);
 118 }
 119
 120 static void _wakeupgen_set(unsigned int irq, unsigned int cpu)
 121 {
 122         u32 val, bit_number;
 123         u8 i;
 124
 125         if (_wakeupgen_get_irq_info(irq, &bit_number, &i))
 126                 return;
 127
 128         val = wakeupgen_readl(i, cpu);
 129         val |= BIT(bit_number);
 130         wakeupgen_writel(val, i, cpu);
 131 }
 132
 133 /*
 134  * Architecture specific Mask extension
 135  */
 136 static void wakeupgen_mask(struct irq_data *d)
 137 {
 138         unsigned long flags;
 139
 140         raw_spin_lock_irqsave(&wakeupgen_lock, flags);
 141         _wakeupgen_clear(d->hwirq, irq_target_cpu[d->hwirq]);
 142         raw_spin_unlock_irqrestore(&wakeupgen_lock, flags);
 143 }
 144
 145 /*
 146  * Architecture specific Unmask extension
 147  */
 148 static void wakeupgen_unmask(struct irq_data *d)
 149 {
 150         unsigned long flags;
 151
 152         raw_spin_lock_irqsave(&wakeupgen_lock, flags);
 153         _wakeupgen_set(d->hwirq, irq_target_cpu[d->hwirq]);
 154         raw_spin_unlock_irqrestore(&wakeupgen_lock, flags);
 155 }
 156
 157 #ifdef CONFIG_HOTPLUG_CPU
 158 static DEFINE_PER_CPU(u32 [MAX_NR_REG_BANKS], irqmasks);
 159
 160 static void _wakeupgen_save_masks(unsigned int cpu)
 161 {
 162         u8 i;
 163
 164         for (i = 0; i < irq_banks; i++)
 165                 per_cpu(irqmasks, cpu)[i] = wakeupgen_readl(i, cpu);
 166 }
 167
 168 static void _wakeupgen_restore_masks(unsigned int cpu)
 169 {
 170         u8 i;
 171
 172         for (i = 0; i < irq_banks; i++)
 173                 wakeupgen_writel(per_cpu(irqmasks, cpu)[i], i, cpu);
 174 }
 175
 176 static void _wakeupgen_set_all(unsigned int cpu, unsigned int reg)
 177 {
 178         u8 i;
 179
 180         for (i = 0; i < irq_banks; i++)
 181                 wakeupgen_writel(reg, i, cpu);
 182 }
 183
 184 /*
 185  * Mask or unmask all interrupts on given CPU.
 186  *      0 = Mask all interrupts on the 'cpu'
 187  *      1 = Unmask all interrupts on the 'cpu'
 188  * Ensure that the initial mask is maintained. This is faster than
 189  * iterating through GIC registers to arrive at the correct masks.
 190  */
 191 static void wakeupgen_irqmask_all(unsigned int cpu, unsigned int set)
 192 {
 193         unsigned long flags;
 194
 195         raw_spin_lock_irqsave(&wakeupgen_lock, flags);
 196         if (set) {
 197                 _wakeupgen_save_masks(cpu);
 198                 _wakeupgen_set_all(cpu, WKG_MASK_ALL);
 199         } else {
 200                 _wakeupgen_set_all(cpu, WKG_UNMASK_ALL);
 201                 _wakeupgen_restore_masks(cpu);
 202         }
 203         raw_spin_unlock_irqrestore(&wakeupgen_lock, flags);
 204 }
 205 #endif
 206
 207 #ifdef CONFIG_CPU_PM
 208 static inline void omap4_irq_save_context(void)
 209 {
 210         u32 i, val;
 211
 212         if (omap_rev() == OMAP4430_REV_ES1_0)
 213                 return;
 214
 215         for (i = 0; i < irq_banks; i++) {
 216                 /* Save the CPUx interrupt mask for IRQ 0 to 127 */
 217                 val = wakeupgen_readl(i, 0);
 218                 sar_writel(val, WAKEUPGENENB_OFFSET_CPU0, i);
 219                 val = wakeupgen_readl(i, 1);
 220                 sar_writel(val, WAKEUPGENENB_OFFSET_CPU1, i);
 221
 222                 /*
 223                  * Disable the secure interrupts for CPUx. The restore
 224                  * code blindly restores secure and non-secure interrupt
 225                  * masks from SAR RAM. Secure interrupts are not suppose
 226                  * to be enabled from HLOS. So overwrite the SAR location
 227                  * so that the secure interrupt remains disabled.
 228                  */
 229                 sar_writel(0x0, WAKEUPGENENB_SECURE_OFFSET_CPU0, i);
 230                 sar_writel(0x0, WAKEUPGENENB_SECURE_OFFSET_CPU1, i);
 231         }
 232
 233         /* Save AuxBoot* registers */
 234         val = readl_relaxed(wakeupgen_base + OMAP_AUX_CORE_BOOT_0);
 235         writel_relaxed(val, sar_base + AUXCOREBOOT0_OFFSET);
 236         val = readl_relaxed(wakeupgen_base + OMAP_AUX_CORE_BOOT_1);
 237         writel_relaxed(val, sar_base + AUXCOREBOOT1_OFFSET);
 238
 239         /* Save SyncReq generation logic */
 240         val = readl_relaxed(wakeupgen_base + OMAP_PTMSYNCREQ_MASK);
 241         writel_relaxed(val, sar_base + PTMSYNCREQ_MASK_OFFSET);
 242         val = readl_relaxed(wakeupgen_base + OMAP_PTMSYNCREQ_EN);
 243         writel_relaxed(val, sar_base + PTMSYNCREQ_EN_OFFSET);
 244
 245         /* Set the Backup Bit Mask status */
 246         val = readl_relaxed(sar_base + SAR_BACKUP_STATUS_OFFSET);
 247         val |= SAR_BACKUP_STATUS_WAKEUPGEN;
 248         writel_relaxed(val, sar_base + SAR_BACKUP_STATUS_OFFSET);
 249
 250 }
 251
 252 static inline void omap5_irq_save_context(void)
 253 {
 254         u32 i, val;
 255
 256         for (i = 0; i < irq_banks; i++) {
 257                 /* Save the CPUx interrupt mask for IRQ 0 to 159 */
 258                 val = wakeupgen_readl(i, 0);
 259                 sar_writel(val, OMAP5_WAKEUPGENENB_OFFSET_CPU0, i);
 260                 val = wakeupgen_readl(i, 1);
 261                 sar_writel(val, OMAP5_WAKEUPGENENB_OFFSET_CPU1, i);
 262                 sar_writel(0x0, OMAP5_WAKEUPGENENB_SECURE_OFFSET_CPU0, i);
 263                 sar_writel(0x0, OMAP5_WAKEUPGENENB_SECURE_OFFSET_CPU1, i);
 264         }
 265
 266         /* Save AuxBoot* registers */
 267         val = readl_relaxed(wakeupgen_base + OMAP_AUX_CORE_BOOT_0);
 268         writel_relaxed(val, sar_base + OMAP5_AUXCOREBOOT0_OFFSET);
 269         val = readl_relaxed(wakeupgen_base + OMAP_AUX_CORE_BOOT_0);
 270         writel_relaxed(val, sar_base + OMAP5_AUXCOREBOOT1_OFFSET);
 271
 272         /* Set the Backup Bit Mask status */
 273         val = readl_relaxed(sar_base + OMAP5_SAR_BACKUP_STATUS_OFFSET);
 274         val |= SAR_BACKUP_STATUS_WAKEUPGEN;
 275         writel_relaxed(val, sar_base + OMAP5_SAR_BACKUP_STATUS_OFFSET);
 276
 277 }
 278
 279 /*
 280  * Save WakeupGen interrupt context in SAR BANK3. Restore is done by
 281  * ROM code. WakeupGen IP is integrated along with GIC to manage the
 282  * interrupt wakeups from CPU low power states. It manages
 283  * masking/unmasking of Shared peripheral interrupts(SPI). So the
 284  * interrupt enable/disable control should be in sync and consistent
 285  * at WakeupGen and GIC so that interrupts are not lost.
 286  */
 287 static void irq_save_context(void)
 288 {
 289         if (!sar_base)
 290                 sar_base = omap4_get_sar_ram_base();
 291
 292         if (soc_is_omap54xx())
 293                 omap5_irq_save_context();
 294         else
 295                 omap4_irq_save_context();
 296 }
 297
 298 /*
 299  * Clear WakeupGen SAR backup status.
 300  */
 301 static void irq_sar_clear(void)
 302 {
 303         u32 val;
 304         u32 offset = SAR_BACKUP_STATUS_OFFSET;
 305
 306         if (soc_is_omap54xx())
 307                 offset = OMAP5_SAR_BACKUP_STATUS_OFFSET;
 308
 309         val = readl_relaxed(sar_base + offset);
 310         val &= ~SAR_BACKUP_STATUS_WAKEUPGEN;
 311         writel_relaxed(val, sar_base + offset);
 312 }
 313
 314 /*
 315  * Save GIC and Wakeupgen interrupt context using secure API
 316  * for HS/EMU devices.
 317  */
 318 static void irq_save_secure_context(void)
 319 {
 320         u32 ret;
 321         ret = omap_secure_dispatcher(OMAP4_HAL_SAVEGIC_INDEX,
 322                                 FLAG_START_CRITICAL,
 323                                 0, 0, 0, 0, 0);
 324         if (ret != API_HAL_RET_VALUE_OK)
 325                 pr_err("GIC and Wakeupgen context save failed\n");
 326 }
 327 #endif
 328
 329 #ifdef CONFIG_HOTPLUG_CPU
 330 static int irq_cpu_hotplug_notify(struct notifier_block *self,
 331                                   unsigned long action, void *hcpu)
 332 {
 333         unsigned int cpu = (unsigned int)hcpu;
 334
 335         switch (action) {
 336         case CPU_ONLINE:
 337                 wakeupgen_irqmask_all(cpu, 0);
 338                 break;
 339         case CPU_DEAD:
 340                 wakeupgen_irqmask_all(cpu, 1);
 341                 break;
 342         }
 343         return NOTIFY_OK;
 344 }
 345
 346 static struct notifier_block __refdata irq_hotplug_notifier = {
 347         .notifier_call = irq_cpu_hotplug_notify,
 348 };
 349
 350 static void __init irq_hotplug_init(void)
 351 {
 352         register_hotcpu_notifier(&irq_hotplug_notifier);
 353 }
 354 #else
 355 static void __init irq_hotplug_init(void)
 356 {}
 357 #endif
 358
 359 #ifdef CONFIG_CPU_PM
 360 static int irq_notifier(struct notifier_block *self, unsigned long cmd, void *v)
 361 {
 362         switch (cmd) {
 363         case CPU_CLUSTER_PM_ENTER:
 364                 if (omap_type() == OMAP2_DEVICE_TYPE_GP)
 365                         irq_save_context();
 366                 else
 367                         irq_save_secure_context();
 368                 break;
 369         case CPU_CLUSTER_PM_EXIT:
 370                 if (omap_type() == OMAP2_DEVICE_TYPE_GP)
 371                         irq_sar_clear();
 372                 break;
 373         }
 374         return NOTIFY_OK;
 375 }
 376
 377 static struct notifier_block irq_notifier_block = {
 378         .notifier_call = irq_notifier,
 379 };
 380
 381 static void __init irq_pm_init(void)
 382 {
 383         /* FIXME: Remove this when MPU OSWR support is added */
 384         if (!soc_is_omap54xx())
 385                 cpu_pm_register_notifier(&irq_notifier_block);
 386 }
 387 #else
 388 static void __init irq_pm_init(void)
 389 {}
 390 #endif
 391
 392 void __iomem *omap_get_wakeupgen_base(void)
 393 {
 394         return wakeupgen_base;
 395 }
 396
 397 int omap_secure_apis_support(void)
 398 {
 399         return omap_secure_apis;
 400 }
 401
 402 /*
 403  * Initialise the wakeupgen module.
 404  */
 405 int __init omap_wakeupgen_init(void)
 406 {
 407         int i;
 408         unsigned int boot_cpu = smp_processor_id();
 409
 410         /* Not supported on OMAP4 ES1.0 silicon */
 411         if (omap_rev() == OMAP4430_REV_ES1_0) {
 412                 WARN(1, "WakeupGen: Not supported on OMAP4430 ES1.0\n");
 413                 return -EPERM;
 414         }
 415
 416         /* Static mapping, never released */
 417         wakeupgen_base = ioremap(OMAP_WKUPGEN_BASE, SZ_4K);
 418         if (WARN_ON(!wakeupgen_base))
 419                 return -ENOMEM;
 420
 421         if (cpu_is_omap44xx()) {
 422                 irq_banks = OMAP4_NR_BANKS;
 423                 max_irqs = OMAP4_NR_IRQS;
 424                 omap_secure_apis = 1;
 425         } else if (soc_is_am43xx()) {
 426                 irq_banks = AM43XX_NR_REG_BANKS;
 427                 max_irqs = AM43XX_IRQS;
 428         }
 429
 430         /* Clear all IRQ bitmasks at wakeupGen level */
 431         for (i = 0; i < irq_banks; i++) {
 432                 wakeupgen_writel(0, i, CPU0_ID);
 433                 if (!soc_is_am43xx())
 434                         wakeupgen_writel(0, i, CPU1_ID);
 435         }
 436
 437         /*
 438          * Override GIC architecture specific functions to add
 439          * OMAP WakeupGen interrupt controller along with GIC
 440          */
 441         gic_arch_extn.irq_mask = wakeupgen_mask;
 442         gic_arch_extn.irq_unmask = wakeupgen_unmask;
 443         gic_arch_extn.flags = IRQCHIP_MASK_ON_SUSPEND | IRQCHIP_SKIP_SET_WAKE;
 444
 445         /*
 446          * FIXME: Add support to set_smp_affinity() once the core
 447          * GIC code has necessary hooks in place.
 448          */
 449
 450         /* Associate all the IRQs to boot CPU like GIC init does. */
 451         for (i = 0; i < max_irqs; i++)
 452                 irq_target_cpu[i] = boot_cpu;
 453
 454         irq_hotplug_init();
 455         irq_pm_init();
 456
 457         return 0;
 458 }