Pileus Git - ~andy/linux/blob - arch/arm/mach-omap2/vp.c

   1 #include <linux/kernel.h>
   2 #include <linux/init.h>
   3
   4 #include <plat/common.h>
   5
   6 #include "voltage.h"
   7 #include "vp.h"
   8 #include "prm-regbits-34xx.h"
   9 #include "prm-regbits-44xx.h"
  10 #include "prm44xx.h"
  11
  12 static void vp_latch_vsel(struct voltagedomain *voltdm)
  13 {
  14         struct omap_vp_instance *vp = voltdm->vp;
  15         u32 vpconfig;
  16         unsigned long uvdc;
  17         char vsel;
  18
  19         uvdc = omap_voltage_get_nom_volt(voltdm);
  20         if (!uvdc) {
  21                 pr_warning("%s: unable to find current voltage for vdd_%s\n",
  22                         __func__, voltdm->name);
  23                 return;
  24         }
  25
  26         if (!voltdm->pmic || !voltdm->pmic->uv_to_vsel) {
  27                 pr_warning("%s: PMIC function to convert voltage in uV to"
  28                         " vsel not registered\n", __func__);
  29                 return;
  30         }
  31
  32         vsel = voltdm->pmic->uv_to_vsel(uvdc);
  33
  34         vpconfig = voltdm->read(vp->vpconfig);
  35         vpconfig &= ~(vp->common->vpconfig_initvoltage_mask |
  36                         vp->common->vpconfig_initvdd);
  37         vpconfig |= vsel << __ffs(vp->common->vpconfig_initvoltage_mask);
  38         voltdm->write(vpconfig, vp->vpconfig);
  39
  40         /* Trigger initVDD value copy to voltage processor */
  41         voltdm->write((vpconfig | vp->common->vpconfig_initvdd),
  42                        vp->vpconfig);
  43
  44         /* Clear initVDD copy trigger bit */
  45         voltdm->write(vpconfig, vp->vpconfig);
  46 }
  47
  48 /* Generic voltage init functions */
  49 void __init omap_vp_init(struct voltagedomain *voltdm)
  50 {
  51         struct omap_vp_instance *vp = voltdm->vp;
  52         u32 val, sys_clk_rate, timeout, waittime;
  53         u32 vddmin, vddmax, vstepmin, vstepmax;
  54
  55         if (!voltdm->read || !voltdm->write) {
  56                 pr_err("%s: No read/write API for accessing vdd_%s regs\n",
  57                         __func__, voltdm->name);
  58                 return;
  59         }
  60
  61         vp->enabled = false;
  62
  63         /* Divide to avoid overflow */
  64         sys_clk_rate = voltdm->sys_clk.rate / 1000;
  65
  66         timeout = (sys_clk_rate * voltdm->pmic->vp_timeout_us) / 1000;
  67         vddmin = voltdm->pmic->vp_vddmin;
  68         vddmax = voltdm->pmic->vp_vddmax;
  69
  70         waittime = ((voltdm->pmic->step_size / voltdm->pmic->slew_rate) *
  71                     sys_clk_rate) / 1000;
  72         vstepmin = voltdm->pmic->vp_vstepmin;
  73         vstepmax = voltdm->pmic->vp_vstepmax;
  74
  75         /*
  76          * VP_CONFIG: error gain is not set here, it will be updated
  77          * on each scale, based on OPP.
  78          */
  79         val = (voltdm->pmic->vp_erroroffset <<
  80                __ffs(voltdm->vp->common->vpconfig_erroroffset_mask)) |
  81                 vp->common->vpconfig_timeouten;
  82         voltdm->write(val, vp->vpconfig);
  83
  84         /* VSTEPMIN */
  85         val = (waittime << vp->common->vstepmin_smpswaittimemin_shift) |
  86                 (vstepmin <<  vp->common->vstepmin_stepmin_shift);
  87         voltdm->write(val, vp->vstepmin);
  88
  89         /* VSTEPMAX */
  90         val = (vstepmax << vp->common->vstepmax_stepmax_shift) |
  91                 (waittime << vp->common->vstepmax_smpswaittimemax_shift);
  92         voltdm->write(val, vp->vstepmax);
  93
  94         /* VLIMITTO */
  95         val = (vddmax << vp->common->vlimitto_vddmax_shift) |
  96                 (vddmin << vp->common->vlimitto_vddmin_shift) |
  97                 (timeout <<  vp->common->vlimitto_timeout_shift);
  98         voltdm->write(val, vp->vlimitto);
  99 }
 100
 101 int omap_vp_update_errorgain(struct voltagedomain *voltdm,
 102                              unsigned long target_volt)
 103 {
 104         struct omap_volt_data *volt_data;
 105
 106         /* Get volt_data corresponding to target_volt */
 107         volt_data = omap_voltage_get_voltdata(voltdm, target_volt);
 108         if (IS_ERR(volt_data))
 109                 return -EINVAL;
 110
 111         /* Setting vp errorgain based on the voltage */
 112         voltdm->rmw(voltdm->vp->common->vpconfig_errorgain_mask,
 113                     volt_data->vp_errgain <<
 114                     __ffs(voltdm->vp->common->vpconfig_errorgain_mask),
 115                     voltdm->vp->vpconfig);
 116
 117         return 0;
 118 }
 119
 120 /* VP force update method of voltage scaling */
 121 int omap_vp_forceupdate_scale(struct voltagedomain *voltdm,
 122                               unsigned long target_volt)
 123 {
 124         struct omap_vp_instance *vp = voltdm->vp;
 125         u32 vpconfig;
 126         u8 target_vsel, current_vsel;
 127         int ret, timeout = 0;
 128
 129         ret = omap_vc_pre_scale(voltdm, target_volt, &target_vsel, &current_vsel);
 130         if (ret)
 131                 return ret;
 132
 133         /*
 134          * Clear all pending TransactionDone interrupt/status. Typical latency
 135          * is <3us
 136          */
 137         while (timeout++ < VP_TRANXDONE_TIMEOUT) {
 138                 vp->common->ops->clear_txdone(vp->id);
 139                 if (!vp->common->ops->check_txdone(vp->id))
 140                         break;
 141                 udelay(1);
 142         }
 143         if (timeout >= VP_TRANXDONE_TIMEOUT) {
 144                 pr_warning("%s: vdd_%s TRANXDONE timeout exceeded."
 145                         "Voltage change aborted", __func__, voltdm->name);
 146                 return -ETIMEDOUT;
 147         }
 148
 149         /* Configure for VP-Force Update */
 150         vpconfig = voltdm->read(vp->vpconfig);
 151         vpconfig &= ~(vp->common->vpconfig_initvdd |
 152                         vp->common->vpconfig_forceupdate |
 153                         vp->common->vpconfig_initvoltage_mask);
 154         vpconfig |= ((target_vsel <<
 155                       __ffs(vp->common->vpconfig_initvoltage_mask)));
 156         voltdm->write(vpconfig, vp->vpconfig);
 157
 158         /* Trigger initVDD value copy to voltage processor */
 159         vpconfig |= vp->common->vpconfig_initvdd;
 160         voltdm->write(vpconfig, vp->vpconfig);
 161
 162         /* Force update of voltage */
 163         vpconfig |= vp->common->vpconfig_forceupdate;
 164         voltdm->write(vpconfig, vp->vpconfig);
 165
 166         /*
 167          * Wait for TransactionDone. Typical latency is <200us.
 168          * Depends on SMPSWAITTIMEMIN/MAX and voltage change
 169          */
 170         timeout = 0;
 171         omap_test_timeout(vp->common->ops->check_txdone(vp->id),
 172                           VP_TRANXDONE_TIMEOUT, timeout);
 173         if (timeout >= VP_TRANXDONE_TIMEOUT)
 174                 pr_err("%s: vdd_%s TRANXDONE timeout exceeded."
 175                         "TRANXDONE never got set after the voltage update\n",
 176                         __func__, voltdm->name);
 177
 178         omap_vc_post_scale(voltdm, target_volt, target_vsel, current_vsel);
 179
 180         /*
 181          * Disable TransactionDone interrupt , clear all status, clear
 182          * control registers
 183          */
 184         timeout = 0;
 185         while (timeout++ < VP_TRANXDONE_TIMEOUT) {
 186                 vp->common->ops->clear_txdone(vp->id);
 187                 if (!vp->common->ops->check_txdone(vp->id))
 188                         break;
 189                 udelay(1);
 190         }
 191
 192         if (timeout >= VP_TRANXDONE_TIMEOUT)
 193                 pr_warning("%s: vdd_%s TRANXDONE timeout exceeded while trying"
 194                         "to clear the TRANXDONE status\n",
 195                         __func__, voltdm->name);
 196
 197         vpconfig = voltdm->read(vp->vpconfig);
 198         /* Clear initVDD copy trigger bit */
 199         vpconfig &= ~vp->common->vpconfig_initvdd;
 200         voltdm->write(vpconfig, vp->vpconfig);
 201         /* Clear force bit */
 202         vpconfig &= ~vp->common->vpconfig_forceupdate;
 203         voltdm->write(vpconfig, vp->vpconfig);
 204
 205         return 0;
 206 }
 207
 208 /**
 209  * omap_vp_get_curr_volt() - API to get the current vp voltage.
 210  * @voltdm:     pointer to the VDD.
 211  *
 212  * This API returns the current voltage for the specified voltage processor
 213  */
 214 unsigned long omap_vp_get_curr_volt(struct voltagedomain *voltdm)
 215 {
 216         struct omap_vp_instance *vp = voltdm->vp;
 217         u8 curr_vsel;
 218
 219         if (!voltdm || IS_ERR(voltdm)) {
 220                 pr_warning("%s: VDD specified does not exist!\n", __func__);
 221                 return 0;
 222         }
 223
 224         if (!voltdm->read) {
 225                 pr_err("%s: No read API for reading vdd_%s regs\n",
 226                         __func__, voltdm->name);
 227                 return 0;
 228         }
 229
 230         curr_vsel = voltdm->read(vp->voltage);
 231
 232         if (!voltdm->pmic || !voltdm->pmic->vsel_to_uv) {
 233                 pr_warning("%s: PMIC function to convert vsel to voltage"
 234                         "in uV not registerd\n", __func__);
 235                 return 0;
 236         }
 237
 238         return voltdm->pmic->vsel_to_uv(curr_vsel);
 239 }
 240
 241 /**
 242  * omap_vp_enable() - API to enable a particular VP
 243  * @voltdm:     pointer to the VDD whose VP is to be enabled.
 244  *
 245  * This API enables a particular voltage processor. Needed by the smartreflex
 246  * class drivers.
 247  */
 248 void omap_vp_enable(struct voltagedomain *voltdm)
 249 {
 250         struct omap_vp_instance *vp;
 251         u32 vpconfig;
 252
 253         if (!voltdm || IS_ERR(voltdm)) {
 254                 pr_warning("%s: VDD specified does not exist!\n", __func__);
 255                 return;
 256         }
 257
 258         vp = voltdm->vp;
 259         if (!voltdm->read || !voltdm->write) {
 260                 pr_err("%s: No read/write API for accessing vdd_%s regs\n",
 261                         __func__, voltdm->name);
 262                 return;
 263         }
 264
 265         /* If VP is already enabled, do nothing. Return */
 266         if (vp->enabled)
 267                 return;
 268
 269         vp_latch_vsel(voltdm);
 270
 271         /* Enable VP */
 272         vpconfig = voltdm->read(vp->vpconfig);
 273         vpconfig |= vp->common->vpconfig_vpenable;
 274         voltdm->write(vpconfig, vp->vpconfig);
 275         vp->enabled = true;
 276 }
 277
 278 /**
 279  * omap_vp_disable() - API to disable a particular VP
 280  * @voltdm:     pointer to the VDD whose VP is to be disabled.
 281  *
 282  * This API disables a particular voltage processor. Needed by the smartreflex
 283  * class drivers.
 284  */
 285 void omap_vp_disable(struct voltagedomain *voltdm)
 286 {
 287         struct omap_vp_instance *vp;
 288         u32 vpconfig;
 289         int timeout;
 290
 291         if (!voltdm || IS_ERR(voltdm)) {
 292                 pr_warning("%s: VDD specified does not exist!\n", __func__);
 293                 return;
 294         }
 295
 296         vp = voltdm->vp;
 297         if (!voltdm->read || !voltdm->write) {
 298                 pr_err("%s: No read/write API for accessing vdd_%s regs\n",
 299                         __func__, voltdm->name);
 300                 return;
 301         }
 302
 303         /* If VP is already disabled, do nothing. Return */
 304         if (!vp->enabled) {
 305                 pr_warning("%s: Trying to disable VP for vdd_%s when"
 306                         "it is already disabled\n", __func__, voltdm->name);
 307                 return;
 308         }
 309
 310         /* Disable VP */
 311         vpconfig = voltdm->read(vp->vpconfig);
 312         vpconfig &= ~vp->common->vpconfig_vpenable;
 313         voltdm->write(vpconfig, vp->vpconfig);
 314
 315         /*
 316          * Wait for VP idle Typical latency is <2us. Maximum latency is ~100us
 317          */
 318         omap_test_timeout((voltdm->read(vp->vstatus)),
 319                           VP_IDLE_TIMEOUT, timeout);
 320
 321         if (timeout >= VP_IDLE_TIMEOUT)
 322                 pr_warning("%s: vdd_%s idle timedout\n",
 323                         __func__, voltdm->name);
 324
 325         vp->enabled = false;
 326
 327         return;
 328 }