arch/arm/mach-omap2/vp.c

   1 #include <linux/kernel.h>
   2 #include <linux/init.h>
   3
   4 #include "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_warn("%s: vdd_%s TRANXDONE timeout exceeded. Voltage change aborted",
 142                         __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. TRANXDONE never got set after the voltage update\n",
 161                        __func__, voltdm->name);
 162
 163         omap_vc_post_scale(voltdm, target_volt, target_vsel, current_vsel);
 164
 165         /*
 166          * Disable TransactionDone interrupt , clear all status, clear
 167          * control registers
 168          */
 169         timeout = 0;
 170         while (timeout++ < VP_TRANXDONE_TIMEOUT) {
 171                 vp->common->ops->clear_txdone(vp->id);
 172                 if (!vp->common->ops->check_txdone(vp->id))
 173                         break;
 174                 udelay(1);
 175         }
 176
 177         if (timeout >= VP_TRANXDONE_TIMEOUT)
 178                 pr_warn("%s: vdd_%s TRANXDONE timeout exceeded while trying to clear the TRANXDONE status\n",
 179                         __func__, voltdm->name);
 180
 181         /* Clear force bit */
 182         voltdm->write(vpconfig, vp->vpconfig);
 183
 184         return 0;
 185 }
 186
 187 /**
 188  * omap_vp_enable() - API to enable a particular VP
 189  * @voltdm:     pointer to the VDD whose VP is to be enabled.
 190  *
 191  * This API enables a particular voltage processor. Needed by the smartreflex
 192  * class drivers.
 193  */
 194 void omap_vp_enable(struct voltagedomain *voltdm)
 195 {
 196         struct omap_vp_instance *vp;
 197         u32 vpconfig, volt;
 198
 199         if (!voltdm || IS_ERR(voltdm)) {
 200                 pr_warning("%s: VDD specified does not exist!\n", __func__);
 201                 return;
 202         }
 203
 204         vp = voltdm->vp;
 205         if (!voltdm->read || !voltdm->write) {
 206                 pr_err("%s: No read/write API for accessing vdd_%s regs\n",
 207                         __func__, voltdm->name);
 208                 return;
 209         }
 210
 211         /* If VP is already enabled, do nothing. Return */
 212         if (vp->enabled)
 213                 return;
 214
 215         volt = voltdm_get_voltage(voltdm);
 216         if (!volt) {
 217                 pr_warning("%s: unable to find current voltage for %s\n",
 218                            __func__, voltdm->name);
 219                 return;
 220         }
 221
 222         vpconfig = _vp_set_init_voltage(voltdm, volt);
 223
 224         /* Enable VP */
 225         vpconfig |= vp->common->vpconfig_vpenable;
 226         voltdm->write(vpconfig, vp->vpconfig);
 227
 228         vp->enabled = true;
 229 }
 230
 231 /**
 232  * omap_vp_disable() - API to disable a particular VP
 233  * @voltdm:     pointer to the VDD whose VP is to be disabled.
 234  *
 235  * This API disables a particular voltage processor. Needed by the smartreflex
 236  * class drivers.
 237  */
 238 void omap_vp_disable(struct voltagedomain *voltdm)
 239 {
 240         struct omap_vp_instance *vp;
 241         u32 vpconfig;
 242         int timeout;
 243
 244         if (!voltdm || IS_ERR(voltdm)) {
 245                 pr_warning("%s: VDD specified does not exist!\n", __func__);
 246                 return;
 247         }
 248
 249         vp = voltdm->vp;
 250         if (!voltdm->read || !voltdm->write) {
 251                 pr_err("%s: No read/write API for accessing vdd_%s regs\n",
 252                         __func__, voltdm->name);
 253                 return;
 254         }
 255
 256         /* If VP is already disabled, do nothing. Return */
 257         if (!vp->enabled) {
 258                 pr_warn("%s: Trying to disable VP for vdd_%s when it is already disabled\n",
 259                         __func__, voltdm->name);
 260                 return;
 261         }
 262
 263         /* Disable VP */
 264         vpconfig = voltdm->read(vp->vpconfig);
 265         vpconfig &= ~vp->common->vpconfig_vpenable;
 266         voltdm->write(vpconfig, vp->vpconfig);
 267
 268         /*
 269          * Wait for VP idle Typical latency is <2us. Maximum latency is ~100us
 270          */
 271         omap_test_timeout((voltdm->read(vp->vstatus)),
 272                           VP_IDLE_TIMEOUT, timeout);
 273
 274         if (timeout >= VP_IDLE_TIMEOUT)
 275                 pr_warning("%s: vdd_%s idle timedout\n",
 276                         __func__, voltdm->name);
 277
 278         vp->enabled = false;
 279
 280         return;
 281 }