arch/arm/mach-omap2/omap-pm-noop.c

   1 /*
   2  * omap-pm-noop.c - OMAP power management interface - dummy version
   3  *
   4  * This code implements the OMAP power management interface to
   5  * drivers, CPUIdle, CPUFreq, and DSP Bridge.  It is strictly for
   6  * debug/demonstration use, as it does nothing but printk() whenever a
   7  * function is called (when DEBUG is defined, below)
   8  *
   9  * Copyright (C) 2008-2009 Texas Instruments, Inc.
  10  * Copyright (C) 2008-2009 Nokia Corporation
  11  * Paul Walmsley
  12  *
  13  * Interface developed by (in alphabetical order):
  14  * Karthik Dasu, Tony Lindgren, Rajendra Nayak, Sakari Poussa, Veeramanikandan
  15  * Raju, Anand Sawant, Igor Stoppa, Paul Walmsley, Richard Woodruff
  16  */
  17
  18 #undef DEBUG
  19
  20 #include <linux/init.h>
  21 #include <linux/cpufreq.h>
  22 #include <linux/device.h>
  23 #include <linux/platform_device.h>
  24
  25 #include "omap_device.h"
  26 #include "omap-pm.h"
  27
  28 static bool off_mode_enabled;
  29 static int dummy_context_loss_counter;
  30
  31 /*
  32  * Device-driver-originated constraints (via board-*.c files)
  33  */
  34
  35 int omap_pm_set_max_mpu_wakeup_lat(struct device *dev, long t)
  36 {
  37         if (!dev || t < -1) {
  38                 WARN(1, "OMAP PM: %s: invalid parameter(s)", __func__);
  39                 return -EINVAL;
  40         }
  41
  42         if (t == -1)
  43                 pr_debug("OMAP PM: remove max MPU wakeup latency constraint: dev %s\n",
  44                          dev_name(dev));
  45         else
  46                 pr_debug("OMAP PM: add max MPU wakeup latency constraint: dev %s, t = %ld usec\n",
  47                          dev_name(dev), t);
  48
  49         /*
  50          * For current Linux, this needs to map the MPU to a
  51          * powerdomain, then go through the list of current max lat
  52          * constraints on the MPU and find the smallest.  If
  53          * the latency constraint has changed, the code should
  54          * recompute the state to enter for the next powerdomain
  55          * state.
  56          *
  57          * TI CDP code can call constraint_set here.
  58          */
  59
  60         return 0;
  61 }
  62
  63 int omap_pm_set_min_bus_tput(struct device *dev, u8 agent_id, unsigned long r)
  64 {
  65         if (!dev || (agent_id != OCP_INITIATOR_AGENT &&
  66             agent_id != OCP_TARGET_AGENT)) {
  67                 WARN(1, "OMAP PM: %s: invalid parameter(s)", __func__);
  68                 return -EINVAL;
  69         }
  70
  71         if (r == 0)
  72                 pr_debug("OMAP PM: remove min bus tput constraint: dev %s for agent_id %d\n",
  73                          dev_name(dev), agent_id);
  74         else
  75                 pr_debug("OMAP PM: add min bus tput constraint: dev %s for agent_id %d: rate %ld KiB\n",
  76                          dev_name(dev), agent_id, r);
  77
  78         /*
  79          * This code should model the interconnect and compute the
  80          * required clock frequency, convert that to a VDD2 OPP ID, then
  81          * set the VDD2 OPP appropriately.
  82          *
  83          * TI CDP code can call constraint_set here on the VDD2 OPP.
  84          */
  85
  86         return 0;
  87 }
  88
  89 int omap_pm_set_max_dev_wakeup_lat(struct device *req_dev, struct device *dev,
  90                                    long t)
  91 {
  92         if (!req_dev || !dev || t < -1) {
  93                 WARN(1, "OMAP PM: %s: invalid parameter(s)", __func__);
  94                 return -EINVAL;
  95         }
  96
  97         if (t == -1)
  98                 pr_debug("OMAP PM: remove max device latency constraint: dev %s\n",
  99                          dev_name(dev));
 100         else
 101                 pr_debug("OMAP PM: add max device latency constraint: dev %s, t = %ld usec\n",
 102                          dev_name(dev), t);
 103
 104         /*
 105          * For current Linux, this needs to map the device to a
 106          * powerdomain, then go through the list of current max lat
 107          * constraints on that powerdomain and find the smallest.  If
 108          * the latency constraint has changed, the code should
 109          * recompute the state to enter for the next powerdomain
 110          * state.  Conceivably, this code should also determine
 111          * whether to actually disable the device clocks or not,
 112          * depending on how long it takes to re-enable the clocks.
 113          *
 114          * TI CDP code can call constraint_set here.
 115          */
 116
 117         return 0;
 118 }
 119
 120 int omap_pm_set_max_sdma_lat(struct device *dev, long t)
 121 {
 122         if (!dev || t < -1) {
 123                 WARN(1, "OMAP PM: %s: invalid parameter(s)", __func__);
 124                 return -EINVAL;
 125         }
 126
 127         if (t == -1)
 128                 pr_debug("OMAP PM: remove max DMA latency constraint: dev %s\n",
 129                          dev_name(dev));
 130         else
 131                 pr_debug("OMAP PM: add max DMA latency constraint: dev %s, t = %ld usec\n",
 132                          dev_name(dev), t);
 133
 134         /*
 135          * For current Linux PM QOS params, this code should scan the
 136          * list of maximum CPU and DMA latencies and select the
 137          * smallest, then set cpu_dma_latency pm_qos_param
 138          * accordingly.
 139          *
 140          * For future Linux PM QOS params, with separate CPU and DMA
 141          * latency params, this code should just set the dma_latency param.
 142          *
 143          * TI CDP code can call constraint_set here.
 144          */
 145
 146         return 0;
 147 }
 148
 149 int omap_pm_set_min_clk_rate(struct device *dev, struct clk *c, long r)
 150 {
 151         if (!dev || !c || r < 0) {
 152                 WARN(1, "OMAP PM: %s: invalid parameter(s)", __func__);
 153                 return -EINVAL;
 154         }
 155
 156         if (r == 0)
 157                 pr_debug("OMAP PM: remove min clk rate constraint: dev %s\n",
 158                          dev_name(dev));
 159         else
 160                 pr_debug("OMAP PM: add min clk rate constraint: dev %s, rate = %ld Hz\n",
 161                          dev_name(dev), r);
 162
 163         /*
 164          * Code in a real implementation should keep track of these
 165          * constraints on the clock, and determine the highest minimum
 166          * clock rate.  It should iterate over each OPP and determine
 167          * whether the OPP will result in a clock rate that would
 168          * satisfy this constraint (and any other PM constraint in effect
 169          * at that time).  Once it finds the lowest-voltage OPP that
 170          * meets those conditions, it should switch to it, or return
 171          * an error if the code is not capable of doing so.
 172          */
 173
 174         return 0;
 175 }
 176
 177 /*
 178  * DSP Bridge-specific constraints
 179  */
 180
 181 const struct omap_opp *omap_pm_dsp_get_opp_table(void)
 182 {
 183         pr_debug("OMAP PM: DSP request for OPP table\n");
 184
 185         /*
 186          * Return DSP frequency table here:  The final item in the
 187          * array should have .rate = .opp_id = 0.
 188          */
 189
 190         return NULL;
 191 }
 192
 193 void omap_pm_dsp_set_min_opp(u8 opp_id)
 194 {
 195         if (opp_id == 0) {
 196                 WARN_ON(1);
 197                 return;
 198         }
 199
 200         pr_debug("OMAP PM: DSP requests minimum VDD1 OPP to be %d\n", opp_id);
 201
 202         /*
 203          *
 204          * For l-o dev tree, our VDD1 clk is keyed on OPP ID, so we
 205          * can just test to see which is higher, the CPU's desired OPP
 206          * ID or the DSP's desired OPP ID, and use whichever is
 207          * highest.
 208          *
 209          * In CDP12.14+, the VDD1 OPP custom clock that controls the DSP
 210          * rate is keyed on MPU speed, not the OPP ID.  So we need to
 211          * map the OPP ID to the MPU speed for use with clk_set_rate()
 212          * if it is higher than the current OPP clock rate.
 213          *
 214          */
 215 }
 216
 217
 218 u8 omap_pm_dsp_get_opp(void)
 219 {
 220         pr_debug("OMAP PM: DSP requests current DSP OPP ID\n");
 221
 222         /*
 223          * For l-o dev tree, call clk_get_rate() on VDD1 OPP clock
 224          *
 225          * CDP12.14+:
 226          * Call clk_get_rate() on the OPP custom clock, map that to an
 227          * OPP ID using the tables defined in board-*.c/chip-*.c files.
 228          */
 229
 230         return 0;
 231 }
 232
 233 /*
 234  * CPUFreq-originated constraint
 235  *
 236  * In the future, this should be handled by custom OPP clocktype
 237  * functions.
 238  */
 239
 240 struct cpufreq_frequency_table **omap_pm_cpu_get_freq_table(void)
 241 {
 242         pr_debug("OMAP PM: CPUFreq request for frequency table\n");
 243
 244         /*
 245          * Return CPUFreq frequency table here: loop over
 246          * all VDD1 clkrates, pull out the mpu_ck frequencies, build
 247          * table
 248          */
 249
 250         return NULL;
 251 }
 252
 253 void omap_pm_cpu_set_freq(unsigned long f)
 254 {
 255         if (f == 0) {
 256                 WARN_ON(1);
 257                 return;
 258         }
 259
 260         pr_debug("OMAP PM: CPUFreq requests CPU frequency to be set to %lu\n",
 261                  f);
 262
 263         /*
 264          * For l-o dev tree, determine whether MPU freq or DSP OPP id
 265          * freq is higher.  Find the OPP ID corresponding to the
 266          * higher frequency.  Call clk_round_rate() and clk_set_rate()
 267          * on the OPP custom clock.
 268          *
 269          * CDP should just be able to set the VDD1 OPP clock rate here.
 270          */
 271 }
 272
 273 unsigned long omap_pm_cpu_get_freq(void)
 274 {
 275         pr_debug("OMAP PM: CPUFreq requests current CPU frequency\n");
 276
 277         /*
 278          * Call clk_get_rate() on the mpu_ck.
 279          */
 280
 281         return 0;
 282 }
 283
 284 /**
 285  * omap_pm_enable_off_mode - notify OMAP PM that off-mode is enabled
 286  *
 287  * Intended for use only by OMAP PM core code to notify this layer
 288  * that off mode has been enabled.
 289  */
 290 void omap_pm_enable_off_mode(void)
 291 {
 292         off_mode_enabled = true;
 293 }
 294
 295 /**
 296  * omap_pm_disable_off_mode - notify OMAP PM that off-mode is disabled
 297  *
 298  * Intended for use only by OMAP PM core code to notify this layer
 299  * that off mode has been disabled.
 300  */
 301 void omap_pm_disable_off_mode(void)
 302 {
 303         off_mode_enabled = false;
 304 }
 305
 306 /*
 307  * Device context loss tracking
 308  */
 309
 310 #ifdef CONFIG_ARCH_OMAP2PLUS
 311
 312 int omap_pm_get_dev_context_loss_count(struct device *dev)
 313 {
 314         struct platform_device *pdev = to_platform_device(dev);
 315         int count;
 316
 317         if (WARN_ON(!dev))
 318                 return -ENODEV;
 319
 320         if (dev->pm_domain == &omap_device_pm_domain) {
 321                 count = omap_device_get_context_loss_count(pdev);
 322         } else {
 323                 WARN_ONCE(off_mode_enabled, "omap_pm: using dummy context loss counter; device %s should be converted to omap_device",
 324                           dev_name(dev));
 325
 326                 count = dummy_context_loss_counter;
 327
 328                 if (off_mode_enabled) {
 329                         count++;
 330                         /*
 331                          * Context loss count has to be a non-negative value.
 332                          * Clear the sign bit to get a value range from 0 to
 333                          * INT_MAX.
 334                          */
 335                         count &= INT_MAX;
 336                         dummy_context_loss_counter = count;
 337                 }
 338         }
 339
 340         pr_debug("OMAP PM: context loss count for dev %s = %d\n",
 341                  dev_name(dev), count);
 342
 343         return count;
 344 }
 345
 346 #else
 347
 348 int omap_pm_get_dev_context_loss_count(struct device *dev)
 349 {
 350         return dummy_context_loss_counter;
 351 }
 352
 353 #endif
 354
 355 /* Should be called before clk framework init */
 356 int __init omap_pm_if_early_init(void)
 357 {
 358         return 0;
 359 }
 360
 361 /* Must be called after clock framework is initialized */
 362 int __init omap_pm_if_init(void)
 363 {
 364         return 0;
 365 }
 366
 367 void omap_pm_if_exit(void)
 368 {
 369         /* Deallocate CPUFreq frequency table here */
 370 }
 371