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         if (!voltdm->vp)
 107                 return -EINVAL;
 108
 109         /* Get volt_data corresponding to target_volt */
 110         volt_data = omap_voltage_get_voltdata(voltdm, target_volt);
 111         if (IS_ERR(volt_data))
 112                 return -EINVAL;
 113
 114         /* Setting vp errorgain based on the voltage */
 115         voltdm->rmw(voltdm->vp->common->vpconfig_errorgain_mask,
 116                     volt_data->vp_errgain <<
 117                     __ffs(voltdm->vp->common->vpconfig_errorgain_mask),
 118                     voltdm->vp->vpconfig);
 119
 120         return 0;
 121 }
 122
 123 /* VP force update method of voltage scaling */
 124 int omap_vp_forceupdate_scale(struct voltagedomain *voltdm,
 125                               unsigned long target_volt)
 126 {
 127         struct omap_vp_instance *vp = voltdm->vp;
 128         u32 vpconfig;
 129         u8 target_vsel, current_vsel;
 130         int ret, timeout = 0;
 131
 132         ret = omap_vc_pre_scale(voltdm, target_volt, &target_vsel, &current_vsel);
 133         if (ret)
 134                 return ret;
 135
 136         /*
 137          * Clear all pending TransactionDone interrupt/status. Typical latency
 138          * is <3us
 139          */
 140         while (timeout++ < VP_TRANXDONE_TIMEOUT) {
 141                 vp->common->ops->clear_txdone(vp->id);
 142                 if (!vp->common->ops->check_txdone(vp->id))
 143                         break;
 144                 udelay(1);
 145         }
 146         if (timeout >= VP_TRANXDONE_TIMEOUT) {
 147                 pr_warning("%s: vdd_%s TRANXDONE timeout exceeded."
 148                         "Voltage change aborted", __func__, voltdm->name);
 149                 return -ETIMEDOUT;
 150         }
 151
 152         /* Configure for VP-Force Update */
 153         vpconfig = voltdm->read(vp->vpconfig);
 154         vpconfig &= ~(vp->common->vpconfig_initvdd |
 155                         vp->common->vpconfig_forceupdate |
 156                         vp->common->vpconfig_initvoltage_mask);
 157         vpconfig |= ((target_vsel <<
 158                       __ffs(vp->common->vpconfig_initvoltage_mask)));
 159         voltdm->write(vpconfig, vp->vpconfig);
 160
 161         /* Trigger initVDD value copy to voltage processor */
 162         vpconfig |= vp->common->vpconfig_initvdd;
 163         voltdm->write(vpconfig, vp->vpconfig);
 164
 165         /* Force update of voltage */
 166         vpconfig |= vp->common->vpconfig_forceupdate;
 167         voltdm->write(vpconfig, vp->vpconfig);
 168
 169         /*
 170          * Wait for TransactionDone. Typical latency is <200us.
 171          * Depends on SMPSWAITTIMEMIN/MAX and voltage change
 172          */
 173         timeout = 0;
 174         omap_test_timeout(vp->common->ops->check_txdone(vp->id),
 175                           VP_TRANXDONE_TIMEOUT, timeout);
 176         if (timeout >= VP_TRANXDONE_TIMEOUT)
 177                 pr_err("%s: vdd_%s TRANXDONE timeout exceeded."
 178                         "TRANXDONE never got set after the voltage update\n",
 179                         __func__, voltdm->name);
 180
 181         omap_vc_post_scale(voltdm, target_volt, target_vsel, current_vsel);
 182
 183         /*
 184          * Disable TransactionDone interrupt , clear all status, clear
 185          * control registers
 186          */
 187         timeout = 0;
 188         while (timeout++ < VP_TRANXDONE_TIMEOUT) {
 189                 vp->common->ops->clear_txdone(vp->id);
 190                 if (!vp->common->ops->check_txdone(vp->id))
 191                         break;
 192                 udelay(1);
 193         }
 194
 195         if (timeout >= VP_TRANXDONE_TIMEOUT)
 196                 pr_warning("%s: vdd_%s TRANXDONE timeout exceeded while trying"
 197                         "to clear the TRANXDONE status\n",
 198                         __func__, voltdm->name);
 199
 200         vpconfig = voltdm->read(vp->vpconfig);
 201         /* Clear initVDD copy trigger bit */
 202         vpconfig &= ~vp->common->vpconfig_initvdd;
 203         voltdm->write(vpconfig, vp->vpconfig);
 204         /* Clear force bit */
 205         vpconfig &= ~vp->common->vpconfig_forceupdate;
 206         voltdm->write(vpconfig, vp->vpconfig);
 207
 208         return 0;
 209 }
 210
 211 /**
 212  * omap_vp_enable() - API to enable a particular VP
 213  * @voltdm:     pointer to the VDD whose VP is to be enabled.
 214  *
 215  * This API enables a particular voltage processor. Needed by the smartreflex
 216  * class drivers.
 217  */
 218 void omap_vp_enable(struct voltagedomain *voltdm)
 219 {
 220         struct omap_vp_instance *vp;
 221         u32 vpconfig;
 222
 223         if (!voltdm || IS_ERR(voltdm)) {
 224                 pr_warning("%s: VDD specified does not exist!\n", __func__);
 225                 return;
 226         }
 227
 228         vp = voltdm->vp;
 229         if (!voltdm->read || !voltdm->write) {
 230                 pr_err("%s: No read/write API for accessing vdd_%s regs\n",
 231                         __func__, voltdm->name);
 232                 return;
 233         }
 234
 235         /* If VP is already enabled, do nothing. Return */
 236         if (vp->enabled)
 237                 return;
 238
 239         vp_latch_vsel(voltdm);
 240
 241         /* Enable VP */
 242         vpconfig = voltdm->read(vp->vpconfig);
 243         vpconfig |= vp->common->vpconfig_vpenable;
 244         voltdm->write(vpconfig, vp->vpconfig);
 245         vp->enabled = true;
 246 }
 247
 248 /**
 249  * omap_vp_disable() - API to disable a particular VP
 250  * @voltdm:     pointer to the VDD whose VP is to be disabled.
 251  *
 252  * This API disables a particular voltage processor. Needed by the smartreflex
 253  * class drivers.
 254  */
 255 void omap_vp_disable(struct voltagedomain *voltdm)
 256 {
 257         struct omap_vp_instance *vp;
 258         u32 vpconfig;
 259         int timeout;
 260
 261         if (!voltdm || IS_ERR(voltdm)) {
 262                 pr_warning("%s: VDD specified does not exist!\n", __func__);
 263                 return;
 264         }
 265
 266         vp = voltdm->vp;
 267         if (!voltdm->read || !voltdm->write) {
 268                 pr_err("%s: No read/write API for accessing vdd_%s regs\n",
 269                         __func__, voltdm->name);
 270                 return;
 271         }
 272
 273         /* If VP is already disabled, do nothing. Return */
 274         if (!vp->enabled) {
 275                 pr_warning("%s: Trying to disable VP for vdd_%s when"
 276                         "it is already disabled\n", __func__, voltdm->name);
 277                 return;
 278         }
 279
 280         /* Disable VP */
 281         vpconfig = voltdm->read(vp->vpconfig);
 282         vpconfig &= ~vp->common->vpconfig_vpenable;
 283         voltdm->write(vpconfig, vp->vpconfig);
 284
 285         /*
 286          * Wait for VP idle Typical latency is <2us. Maximum latency is ~100us
 287          */
 288         omap_test_timeout((voltdm->read(vp->vstatus)),
 289                           VP_IDLE_TIMEOUT, timeout);
 290
 291         if (timeout >= VP_IDLE_TIMEOUT)
 292                 pr_warning("%s: vdd_%s idle timedout\n",
 293                         __func__, voltdm->name);
 294
 295         vp->enabled = false;
 296
 297         return;
 298 }