recipes-bsp/linux/linux-omap/dvfs/0010-OMAP-Voltage-layer-changes-to-support-DVFS.patch

   1 From 3a9b78f58772645a9e1337454faed4e313e55368 Mon Sep 17 00:00:00 2001
   2 From: Thara Gopinath <thara@ti.com>
   3 Date: Fri, 29 Oct 2010 20:43:34 +0530
   4 Subject: [PATCH 10/19] OMAP: Voltage layer changes to support DVFS.
   5
   6 This patch introduces an API to take in the voltage domain and the
   7 new voltage as parameter and to scale all the scalable devices
   8 associated with the the voltage domain to the rate corresponding to the
   9 new voltage and scale the voltage domain to the new voltage.
  10
  11 Signed-off-by: Thara Gopinath <thara@ti.com>
  12 ---
  13  arch/arm/mach-omap2/voltage.c             |   69 +++++++++++++++++++++++++++++
  14  arch/arm/plat-omap/include/plat/voltage.h |    7 +++
  15  2 files changed, 76 insertions(+), 0 deletions(-)
  16
  17 diff --git a/arch/arm/mach-omap2/voltage.c b/arch/arm/mach-omap2/voltage.c
  18 index 7381fa6..9adf9d1 100644
  19 --- a/arch/arm/mach-omap2/voltage.c
  20 +++ b/arch/arm/mach-omap2/voltage.c
  21 @@ -27,9 +27,11 @@
  22  #include <linux/spinlock.h>
  23  #include <linux/plist.h>
  24  #include <linux/slab.h>
  25 +#include <linux/opp.h>
  26
  27  #include <plat/common.h>
  28  #include <plat/voltage.h>
  29 +#include <plat/omap_device.h>
  30
  31  #include "prm-regbits-34xx.h"
  32  #include "prm-regbits-44xx.h"
  33 @@ -1656,6 +1658,73 @@ struct voltagedomain *omap_voltage_domain_lookup(char *name)
  34  }
  35
  36  /**
  37 + * omap_voltage_scale : API to scale the devices associated with a
  38 + *                     voltage domain vdd voltage.
  39 + * @volt_domain : the voltage domain to be scaled
  40 + * @volt : the new voltage for the voltage domain
  41 + *
  42 + * This API runs through the list of devices associated with the
  43 + * voltage domain and scales the device rates to those corresponding
  44 + * to the new voltage of the voltage domain. This API also scales
  45 + * the voltage domain voltage to the new value. Returns 0 on success
  46 + * else the error value.
  47 + */
  48 +int omap_voltage_scale(struct voltagedomain *voltdm, unsigned long volt)
  49 +{
  50 +       unsigned long curr_volt;
  51 +       int is_volt_scaled = 0;
  52 +       struct omap_vdd_info *vdd;
  53 +       struct omap_vdd_dev_list *temp_dev;
  54 +
  55 +       if (!voltdm || IS_ERR(voltdm)) {
  56 +               pr_warning("%s: VDD specified does not exist!\n", __func__);
  57 +               return -EINVAL;
  58 +       }
  59 +
  60 +       vdd = container_of(voltdm, struct omap_vdd_info, voltdm);
  61 +
  62 +       mutex_lock(&vdd->scaling_mutex);
  63 +
  64 +       curr_volt = omap_voltage_get_nom_volt(voltdm);
  65 +
  66 +       if (curr_volt == volt) {
  67 +               is_volt_scaled = 1;
  68 +       } else if (curr_volt < volt) {
  69 +               omap_voltage_scale_vdd(voltdm, volt);
  70 +               is_volt_scaled = 1;
  71 +       }
  72 +
  73 +       list_for_each_entry(temp_dev, &vdd->dev_list, node) {
  74 +               struct device *dev;
  75 +               struct opp *opp;
  76 +               unsigned long freq;
  77 +
  78 +               dev = temp_dev->dev;
  79 +
  80 +               opp = opp_find_voltage(dev, volt);
  81 +               if (IS_ERR(opp))
  82 +                       continue;
  83 +
  84 +               freq = opp_get_freq(opp);
  85 +
  86 +               if (freq == omap_device_get_rate(dev)) {
  87 +                       dev_warn(dev, "%s: Already at the requested"
  88 +                               "rate %ld\n", __func__, freq);
  89 +                       continue;
  90 +               }
  91 +
  92 +               omap_device_set_rate(dev, freq);
  93 +       }
  94 +
  95 +       if (!is_volt_scaled)
  96 +               omap_voltage_scale_vdd(voltdm, volt);
  97 +
  98 +       mutex_unlock(&vdd->scaling_mutex);
  99 +
 100 +       return 0;
 101 +}
 102 +
 103 +/**
 104   * omap_voltage_late_init() - Init the various voltage parameters
 105   *
 106   * This API is to be called in the later stages of the
 107 diff --git a/arch/arm/plat-omap/include/plat/voltage.h b/arch/arm/plat-omap/include/plat/voltage.h
 108 index adbc6af..6782c5e 100644
 109 --- a/arch/arm/plat-omap/include/plat/voltage.h
 110 +++ b/arch/arm/plat-omap/include/plat/voltage.h
 111 @@ -135,6 +135,7 @@ int omap_voltage_late_init(void);
 112  int omap_voltage_add_request(struct voltagedomain *voltdm, struct device *dev,
 113                 unsigned long *volt);
 114  int omap_voltage_add_dev(struct voltagedomain *voltdm, struct device *dev);
 115 +int omap_voltage_scale(struct voltagedomain *voltdm, unsigned long volt);
 116  #else
 117  static inline int omap_voltage_register_pmic(struct voltagedomain *voltdm,
 118                 struct omap_volt_pmic_info *pmic_info) {}
 119 @@ -154,6 +155,12 @@ static inline int omap_voltage_add_dev(struct voltagedomain *voltdm,
 120  {
 121         return -EINVAL;
 122  }
 123 +
 124 +static inline int omap_voltage_scale(struct voltagedomain *voltdm,
 125 +               unsigned long volt)
 126 +{
 127 +       return -EINVAL;
 128 +}
 129  #endif
 130
 131  #endif
 132 --
 133 1.6.6.1
 134