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