1 /* 2 * MPC83xx suspend support 3 * 4 * Author: Scott Wood <scottwood@freescale.com> 5 * 6 * Copyright (c) 2006-2007 Freescale Semiconductor, Inc. 7 * 8 * This program is free software; you can redistribute it and/or modify it 9 * under the terms of the GNU General Public License version 2 as published 10 * by the Free Software Foundation. 11 */ 12 13 #include <linux/init.h> 14 #include <linux/pm.h> 15 #include <linux/types.h> 16 #include <linux/ioport.h> 17 #include <linux/interrupt.h> 18 #include <linux/wait.h> 19 #include <linux/kthread.h> 20 #include <linux/freezer.h> 21 #include <linux/suspend.h> 22 #include <linux/fsl_devices.h> 23 #include <linux/of_platform.h> 24 25 #include <asm/reg.h> 26 #include <asm/io.h> 27 #include <asm/time.h> 28 #include <asm/mpc6xx.h> 29 30 #include <sysdev/fsl_soc.h> 31 32 #define PMCCR1_NEXT_STATE 0x0C /* Next state for power management */ 33 #define PMCCR1_NEXT_STATE_SHIFT 2 34 #define PMCCR1_CURR_STATE 0x03 /* Current state for power management*/ 35 #define IMMR_RCW_OFFSET 0x900 36 #define RCW_PCI_HOST 0x80000000 37 38 void mpc83xx_enter_deep_sleep(phys_addr_t immrbase); 39 40 struct mpc83xx_pmc { 41 u32 config; 42 #define PMCCR_DLPEN 2 /* DDR SDRAM low power enable */ 43 #define PMCCR_SLPEN 1 /* System low power enable */ 44 45 u32 event; 46 u32 mask; 47 /* All but PMCI are deep-sleep only */ 48 #define PMCER_GPIO 0x100 49 #define PMCER_PCI 0x080 50 #define PMCER_USB 0x040 51 #define PMCER_ETSEC1 0x020 52 #define PMCER_ETSEC2 0x010 53 #define PMCER_TIMER 0x008 54 #define PMCER_INT1 0x004 55 #define PMCER_INT2 0x002 56 #define PMCER_PMCI 0x001 57 #define PMCER_ALL 0x1FF 58 59 /* deep-sleep only */ 60 u32 config1; 61 #define PMCCR1_USE_STATE 0x80000000 62 #define PMCCR1_PME_EN 0x00000080 63 #define PMCCR1_ASSERT_PME 0x00000040 64 #define PMCCR1_POWER_OFF 0x00000020 65 66 /* deep-sleep only */ 67 u32 config2; 68 }; 69 70 struct mpc83xx_rcw { 71 u32 rcwlr; 72 u32 rcwhr; 73 }; 74 75 struct mpc83xx_clock { 76 u32 spmr; 77 u32 occr; 78 u32 sccr; 79 }; 80 81 struct pmc_type { 82 int has_deep_sleep; 83 }; 84 85 static struct of_device *pmc_dev; 86 static int has_deep_sleep, deep_sleeping; 87 static int pmc_irq; 88 static struct mpc83xx_pmc __iomem *pmc_regs; 89 static struct mpc83xx_clock __iomem *clock_regs; 90 static int is_pci_agent, wake_from_pci; 91 static phys_addr_t immrbase; 92 static int pci_pm_state; 93 static DECLARE_WAIT_QUEUE_HEAD(agent_wq); 94 95 int fsl_deep_sleep(void) 96 { 97 return deep_sleeping; 98 } 99 100 static int mpc83xx_change_state(void) 101 { 102 u32 curr_state; 103 u32 reg_cfg1 = in_be32(&pmc_regs->config1); 104 105 if (is_pci_agent) { 106 pci_pm_state = (reg_cfg1 & PMCCR1_NEXT_STATE) >> 107 PMCCR1_NEXT_STATE_SHIFT; 108 curr_state = reg_cfg1 & PMCCR1_CURR_STATE; 109 110 if (curr_state != pci_pm_state) { 111 reg_cfg1 &= ~PMCCR1_CURR_STATE; 112 reg_cfg1 |= pci_pm_state; 113 out_be32(&pmc_regs->config1, reg_cfg1); 114 115 wake_up(&agent_wq); 116 return 1; 117 } 118 } 119 120 return 0; 121 } 122 123 static irqreturn_t pmc_irq_handler(int irq, void *dev_id) 124 { 125 u32 event = in_be32(&pmc_regs->event); 126 int ret = IRQ_NONE; 127 128 if (mpc83xx_change_state()) 129 ret = IRQ_HANDLED; 130 131 if (event) { 132 out_be32(&pmc_regs->event, event); 133 ret = IRQ_HANDLED; 134 } 135 136 return ret; 137 } 138 139 static int mpc83xx_suspend_enter(suspend_state_t state) 140 { 141 int ret = -EAGAIN; 142 143 /* Don't go to sleep if there's a race where pci_pm_state changes 144 * between the agent thread checking it and the PM code disabling 145 * interrupts. 146 */ 147 if (wake_from_pci) { 148 if (pci_pm_state != (deep_sleeping ? 3 : 2)) 149 goto out; 150 151 out_be32(&pmc_regs->config1, 152 in_be32(&pmc_regs->config1) | PMCCR1_PME_EN); 153 } 154 155 /* Put the system into low-power mode and the RAM 156 * into self-refresh mode once the core goes to 157 * sleep. 158 */ 159 160 out_be32(&pmc_regs->config, PMCCR_SLPEN | PMCCR_DLPEN); 161 162 /* If it has deep sleep (i.e. it's an 831x or compatible), 163 * disable power to the core upon entering sleep mode. This will 164 * require going through the boot firmware upon a wakeup event. 165 */ 166 167 if (deep_sleeping) { 168 out_be32(&pmc_regs->mask, PMCER_ALL); 169 170 out_be32(&pmc_regs->config1, 171 in_be32(&pmc_regs->config1) | PMCCR1_POWER_OFF); 172 173 enable_kernel_fp(); 174 175 mpc83xx_enter_deep_sleep(immrbase); 176 177 out_be32(&pmc_regs->config1, 178 in_be32(&pmc_regs->config1) & ~PMCCR1_POWER_OFF); 179 180 out_be32(&pmc_regs->mask, PMCER_PMCI); 181 } else { 182 out_be32(&pmc_regs->mask, PMCER_PMCI); 183 184 mpc6xx_enter_standby(); 185 } 186 187 ret = 0; 188 189 out: 190 out_be32(&pmc_regs->config1, 191 in_be32(&pmc_regs->config1) & ~PMCCR1_PME_EN); 192 193 return ret; 194 } 195 196 static void mpc83xx_suspend_finish(void) 197 { 198 deep_sleeping = 0; 199 } 200 201 static int mpc83xx_suspend_valid(suspend_state_t state) 202 { 203 return state == PM_SUSPEND_STANDBY || state == PM_SUSPEND_MEM; 204 } 205 206 static int mpc83xx_suspend_begin(suspend_state_t state) 207 { 208 switch (state) { 209 case PM_SUSPEND_STANDBY: 210 deep_sleeping = 0; 211 return 0; 212 213 case PM_SUSPEND_MEM: 214 if (has_deep_sleep) 215 deep_sleeping = 1; 216 217 return 0; 218 219 default: 220 return -EINVAL; 221 } 222 } 223 224 static int agent_thread_fn(void *data) 225 { 226 while (1) { 227 wait_event_interruptible(agent_wq, pci_pm_state >= 2); 228 try_to_freeze(); 229 230 if (signal_pending(current) || pci_pm_state < 2) 231 continue; 232 233 /* With a preemptible kernel (or SMP), this could race with 234 * a userspace-driven suspend request. It's probably best 235 * to avoid mixing the two with such a configuration (or 236 * else fix it by adding a mutex to state_store that we can 237 * synchronize with). 238 */ 239 240 wake_from_pci = 1; 241 242 pm_suspend(pci_pm_state == 3 ? PM_SUSPEND_MEM : 243 PM_SUSPEND_STANDBY); 244 245 wake_from_pci = 0; 246 } 247 248 return 0; 249 } 250 251 static void mpc83xx_set_agent(void) 252 { 253 out_be32(&pmc_regs->config1, PMCCR1_USE_STATE); 254 out_be32(&pmc_regs->mask, PMCER_PMCI); 255 256 kthread_run(agent_thread_fn, NULL, "PCI power mgt"); 257 } 258 259 static int mpc83xx_is_pci_agent(void) 260 { 261 struct mpc83xx_rcw __iomem *rcw_regs; 262 int ret; 263 264 rcw_regs = ioremap(get_immrbase() + IMMR_RCW_OFFSET, 265 sizeof(struct mpc83xx_rcw)); 266 267 if (!rcw_regs) 268 return -ENOMEM; 269 270 ret = !(in_be32(&rcw_regs->rcwhr) & RCW_PCI_HOST); 271 272 iounmap(rcw_regs); 273 return ret; 274 } 275 276 static struct platform_suspend_ops mpc83xx_suspend_ops = { 277 .valid = mpc83xx_suspend_valid, 278 .begin = mpc83xx_suspend_begin, 279 .enter = mpc83xx_suspend_enter, 280 .finish = mpc83xx_suspend_finish, 281 }; 282 283 static int pmc_probe(struct of_device *ofdev, 284 const struct of_device_id *match) 285 { 286 struct device_node *np = ofdev->node; 287 struct resource res; 288 struct pmc_type *type = match->data; 289 int ret = 0; 290 291 if (!of_device_is_available(np)) 292 return -ENODEV; 293 294 has_deep_sleep = type->has_deep_sleep; 295 immrbase = get_immrbase(); 296 pmc_dev = ofdev; 297 298 is_pci_agent = mpc83xx_is_pci_agent(); 299 if (is_pci_agent < 0) 300 return is_pci_agent; 301 302 ret = of_address_to_resource(np, 0, &res); 303 if (ret) 304 return -ENODEV; 305 306 pmc_irq = irq_of_parse_and_map(np, 0); 307 if (pmc_irq != NO_IRQ) { 308 ret = request_irq(pmc_irq, pmc_irq_handler, IRQF_SHARED, 309 "pmc", ofdev); 310 311 if (ret) 312 return -EBUSY; 313 } 314 315 pmc_regs = ioremap(res.start, sizeof(struct mpc83xx_pmc)); 316 317 if (!pmc_regs) { 318 ret = -ENOMEM; 319 goto out; 320 } 321 322 ret = of_address_to_resource(np, 1, &res); 323 if (ret) { 324 ret = -ENODEV; 325 goto out_pmc; 326 } 327 328 clock_regs = ioremap(res.start, sizeof(struct mpc83xx_pmc)); 329 330 if (!clock_regs) { 331 ret = -ENOMEM; 332 goto out_pmc; 333 } 334 335 if (is_pci_agent) 336 mpc83xx_set_agent(); 337 338 suspend_set_ops(&mpc83xx_suspend_ops); 339 return 0; 340 341 out_pmc: 342 iounmap(pmc_regs); 343 out: 344 if (pmc_irq != NO_IRQ) 345 free_irq(pmc_irq, ofdev); 346 347 return ret; 348 } 349 350 static int pmc_remove(struct of_device *ofdev) 351 { 352 return -EPERM; 353 }; 354 355 static struct pmc_type pmc_types[] = { 356 { 357 .has_deep_sleep = 1, 358 }, 359 { 360 .has_deep_sleep = 0, 361 } 362 }; 363 364 static struct of_device_id pmc_match[] = { 365 { 366 .compatible = "fsl,mpc8313-pmc", 367 .data = &pmc_types[0], 368 }, 369 { 370 .compatible = "fsl,mpc8349-pmc", 371 .data = &pmc_types[1], 372 }, 373 {} 374 }; 375 376 static struct of_platform_driver pmc_driver = { 377 .name = "mpc83xx-pmc", 378 .match_table = pmc_match, 379 .probe = pmc_probe, 380 .remove = pmc_remove 381 }; 382 383 static int pmc_init(void) 384 { 385 return of_register_platform_driver(&pmc_driver); 386 } 387 388 module_init(pmc_init); 389