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