arch/arm/plat-omap/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 /* Interface documentation is in mach/omap-pm.h */
  26 #include <plat/omap-pm.h>
  27 #include <plat/omap_device.h>
  28
  29 static bool off_mode_enabled;
  30 static int dummy_context_loss_counter;
  31
  32 /*
  33  * Device-driver-originated constraints (via board-*.c files)
  34  */
  35
  36 int omap_pm_set_max_mpu_wakeup_lat(struct device *dev, long t)
  37 {
  38         if (!dev || t < -1) {
  39                 WARN(1, "OMAP PM: %s: invalid parameter(s)", __func__);
  40                 return -EINVAL;
  41         };
  42
  43         if (t == -1)
  44                 pr_debug("OMAP PM: remove max MPU wakeup latency constraint: "
  45                          "dev %s\n", dev_name(dev));
  46         else
  47                 pr_debug("OMAP PM: add max MPU wakeup latency constraint: "
  48                          "dev %s, t = %ld usec\n", dev_name(dev), t);
  49
  50         /*
  51          * For current Linux, this needs to map the MPU to a
  52          * powerdomain, then go through the list of current max lat
  53          * constraints on the MPU and find the smallest.  If
  54          * the latency constraint has changed, the code should
  55          * recompute the state to enter for the next powerdomain
  56          * state.
  57          *
  58          * TI CDP code can call constraint_set here.
  59          */
  60
  61         return 0;
  62 }
  63
  64 int omap_pm_set_min_bus_tput(struct device *dev, u8 agent_id, unsigned long r)
  65 {
  66         if (!dev || (agent_id != OCP_INITIATOR_AGENT &&
  67             agent_id != OCP_TARGET_AGENT)) {
  68                 WARN(1, "OMAP PM: %s: invalid parameter(s)", __func__);
  69                 return -EINVAL;
  70         };
  71
  72         if (r == 0)
  73                 pr_debug("OMAP PM: remove min bus tput constraint: "
  74                          "dev %s for agent_id %d\n", dev_name(dev), agent_id);
  75         else
  76                 pr_debug("OMAP PM: add min bus tput constraint: "
  77                          "dev %s for agent_id %d: rate %ld KiB\n",
  78                          dev_name(dev), agent_id, r);
  79
  80         /*
  81          * This code should model the interconnect and compute the
  82          * required clock frequency, convert that to a VDD2 OPP ID, then
  83          * set the VDD2 OPP appropriately.
  84          *
  85          * TI CDP code can call constraint_set here on the VDD2 OPP.
  86          */
  87
  88         return 0;
  89 }
  90
  91 int omap_pm_set_max_dev_wakeup_lat(struct device *req_dev, struct device *dev,
  92                                    long t)
  93 {
  94         if (!req_dev || !dev || t < -1) {
  95                 WARN(1, "OMAP PM: %s: invalid parameter(s)", __func__);
  96                 return -EINVAL;
  97         };
  98
  99         if (t == -1)
 100                 pr_debug("OMAP PM: remove max device latency constraint: "
 101                          "dev %s\n", dev_name(dev));
 102         else
 103                 pr_debug("OMAP PM: add max device latency constraint: "
 104                          "dev %s, t = %ld usec\n", dev_name(dev), t);
 105
 106         /*
 107          * For current Linux, this needs to map the device to a
 108          * powerdomain, then go through the list of current max lat
 109          * constraints on that powerdomain and find the smallest.  If
 110          * the latency constraint has changed, the code should
 111          * recompute the state to enter for the next powerdomain
 112          * state.  Conceivably, this code should also determine
 113          * whether to actually disable the device clocks or not,
 114          * depending on how long it takes to re-enable the clocks.
 115          *
 116          * TI CDP code can call constraint_set here.
 117          */
 118
 119         return 0;
 120 }
 121
 122 int omap_pm_set_max_sdma_lat(struct device *dev, long t)
 123 {
 124         if (!dev || t < -1) {
 125                 WARN(1, "OMAP PM: %s: invalid parameter(s)", __func__);
 126                 return -EINVAL;
 127         };
 128
 129         if (t == -1)
 130                 pr_debug("OMAP PM: remove max DMA latency constraint: "
 131                          "dev %s\n", dev_name(dev));
 132         else
 133                 pr_debug("OMAP PM: add max DMA latency constraint: "
 134                          "dev %s, t = %ld usec\n", dev_name(dev), t);
 135
 136         /*
 137          * For current Linux PM QOS params, this code should scan the
 138          * list of maximum CPU and DMA latencies and select the
 139          * smallest, then set cpu_dma_latency pm_qos_param
 140          * accordingly.
 141          *
 142          * For future Linux PM QOS params, with separate CPU and DMA
 143          * latency params, this code should just set the dma_latency param.
 144          *
 145          * TI CDP code can call constraint_set here.
 146          */
 147
 148         return 0;
 149 }
 150
 151 int omap_pm_set_min_clk_rate(struct device *dev, struct clk *c, long r)
 152 {
 153         if (!dev || !c || r < 0) {
 154                 WARN(1, "OMAP PM: %s: invalid parameter(s)", __func__);
 155                 return -EINVAL;
 156         }
 157
 158         if (r == 0)
 159                 pr_debug("OMAP PM: remove min clk rate constraint: "
 160                          "dev %s\n", dev_name(dev));
 161         else
 162                 pr_debug("OMAP PM: add min clk rate constraint: "
 163                          "dev %s, rate = %ld Hz\n", dev_name(dev), r);
 164
 165         /*
 166          * Code in a real implementation should keep track of these
 167          * constraints on the clock, and determine the highest minimum
 168          * clock rate.  It should iterate over each OPP and determine
 169          * whether the OPP will result in a clock rate that would
 170          * satisfy this constraint (and any other PM constraint in effect
 171          * at that time).  Once it finds the lowest-voltage OPP that
 172          * meets those conditions, it should switch to it, or return
 173          * an error if the code is not capable of doing so.
 174          */
 175
 176         return 0;
 177 }
 178
 179 /*
 180  * DSP Bridge-specific constraints
 181  */
 182
 183 const struct omap_opp *omap_pm_dsp_get_opp_table(void)
 184 {
 185         pr_debug("OMAP PM: DSP request for OPP table\n");
 186
 187         /*
 188          * Return DSP frequency table here:  The final item in the
 189          * array should have .rate = .opp_id = 0.
 190          */
 191
 192         return NULL;
 193 }
 194
 195 void omap_pm_dsp_set_min_opp(u8 opp_id)
 196 {
 197         if (opp_id == 0) {
 198                 WARN_ON(1);
 199                 return;
 200         }
 201
 202         pr_debug("OMAP PM: DSP requests minimum VDD1 OPP to be %d\n", opp_id);
 203
 204         /*
 205          *
 206          * For l-o dev tree, our VDD1 clk is keyed on OPP ID, so we
 207          * can just test to see which is higher, the CPU's desired OPP
 208          * ID or the DSP's desired OPP ID, and use whichever is
 209          * highest.
 210          *
 211          * In CDP12.14+, the VDD1 OPP custom clock that controls the DSP
 212          * rate is keyed on MPU speed, not the OPP ID.  So we need to
 213          * map the OPP ID to the MPU speed for use with clk_set_rate()
 214          * if it is higher than the current OPP clock rate.
 215          *
 216          */
 217 }
 218
 219
 220 u8 omap_pm_dsp_get_opp(void)
 221 {
 222         pr_debug("OMAP PM: DSP requests current DSP OPP ID\n");
 223
 224         /*
 225          * For l-o dev tree, call clk_get_rate() on VDD1 OPP clock
 226          *
 227          * CDP12.14+:
 228          * Call clk_get_rate() on the OPP custom clock, map that to an
 229          * OPP ID using the tables defined in board-*.c/chip-*.c files.
 230          */
 231
 232         return 0;
 233 }
 234
 235 /*
 236  * CPUFreq-originated constraint
 237  *
 238  * In the future, this should be handled by custom OPP clocktype
 239  * functions.
 240  */
 241
 242 struct cpufreq_frequency_table **omap_pm_cpu_get_freq_table(void)
 243 {
 244         pr_debug("OMAP PM: CPUFreq request for frequency table\n");
 245
 246         /*
 247          * Return CPUFreq frequency table here: loop over
 248          * all VDD1 clkrates, pull out the mpu_ck frequencies, build
 249          * table
 250          */
 251
 252         return NULL;
 253 }
 254
 255 void omap_pm_cpu_set_freq(unsigned long f)
 256 {
 257         if (f == 0) {
 258                 WARN_ON(1);
 259                 return;
 260         }
 261
 262         pr_debug("OMAP PM: CPUFreq requests CPU frequency to be set to %lu\n",
 263                  f);
 264
 265         /*
 266          * For l-o dev tree, determine whether MPU freq or DSP OPP id
 267          * freq is higher.  Find the OPP ID corresponding to the
 268          * higher frequency.  Call clk_round_rate() and clk_set_rate()
 269          * on the OPP custom clock.
 270          *
 271          * CDP should just be able to set the VDD1 OPP clock rate here.
 272          */
 273 }
 274
 275 unsigned long omap_pm_cpu_get_freq(void)
 276 {
 277         pr_debug("OMAP PM: CPUFreq requests current CPU frequency\n");
 278
 279         /*
 280          * Call clk_get_rate() on the mpu_ck.
 281          */
 282
 283         return 0;
 284 }
 285
 286 /**
 287  * omap_pm_enable_off_mode - notify OMAP PM that off-mode is enabled
 288  *
 289  * Intended for use only by OMAP PM core code to notify this layer
 290  * that off mode has been enabled.
 291  */
 292 void omap_pm_enable_off_mode(void)
 293 {
 294         off_mode_enabled = true;
 295 }
 296
 297 /**
 298  * omap_pm_disable_off_mode - notify OMAP PM that off-mode is disabled
 299  *
 300  * Intended for use only by OMAP PM core code to notify this layer
 301  * that off mode has been disabled.
 302  */
 303 void omap_pm_disable_off_mode(void)
 304 {
 305         off_mode_enabled = false;
 306 }
 307
 308 /*
 309  * Device context loss tracking
 310  */
 311
 312 #ifdef CONFIG_ARCH_OMAP2PLUS
 313
 314 int omap_pm_get_dev_context_loss_count(struct device *dev)
 315 {
 316         struct platform_device *pdev = to_platform_device(dev);
 317         int count;
 318
 319         if (WARN_ON(!dev))
 320                 return -ENODEV;
 321
 322         if (dev->parent == &omap_device_parent) {
 323                 count = omap_device_get_context_loss_count(pdev);
 324         } else {
 325                 WARN_ONCE(off_mode_enabled, "omap_pm: using dummy context loss counter; device %s should be converted to omap_device",
 326                           dev_name(dev));
 327
 328                 count = dummy_context_loss_counter;
 329
 330                 if (off_mode_enabled) {
 331                         count++;
 332                         /*
 333                          * Context loss count has to be a non-negative value.
 334                          * Clear the sign bit to get a value range from 0 to
 335                          * INT_MAX.
 336                          */
 337                         count &= INT_MAX;
 338                         dummy_context_loss_counter = count;
 339                 }
 340         }
 341
 342         pr_debug("OMAP PM: context loss count for dev %s = %d\n",
 343                  dev_name(dev), count);
 344
 345         return count;
 346 }
 347
 348 #else
 349
 350 int omap_pm_get_dev_context_loss_count(struct device *dev)
 351 {
 352         return dummy_context_loss_counter;
 353 }
 354
 355 #endif
 356
 357 /* Should be called before clk framework init */
 358 int __init omap_pm_if_early_init(void)
 359 {
 360         return 0;
 361 }
 362
 363 /* Must be called after clock framework is initialized */
 364 int __init omap_pm_if_init(void)
 365 {
 366         return 0;
 367 }
 368
 369 void omap_pm_if_exit(void)
 370 {
 371         /* Deallocate CPUFreq frequency table here */
 372 }
 373