There could be dependencies between various voltage domains for
maintaining system performance or hardware limitation reasons
like VDD<X> should be at voltage v1 when VDD<Y> is at voltage v2.
This patch introduce dependent vdd information structures in the
voltage layer which can be used to populate these dependencies
for a voltage domain. This patch also adds support to scale
the dependent vdd and the scalable devices belonging to it
during the scaling of a main vdd through omap_voltage_scale.
Signed-off-by: Thara Gopinath <thara@xxxxxx>
---
arch/arm/mach-omap2/voltage.c | 122 +++++++++++++++++++++++++++++++++++++++++
1 files changed, 122 insertions(+), 0 deletions(-)
diff --git a/arch/arm/mach-omap2/voltage.c b/arch/arm/mach-omap2/voltage.c
index 458f8c1..67748b0 100644
--- a/arch/arm/mach-omap2/voltage.c
+++ b/arch/arm/mach-omap2/voltage.c
@@ -90,6 +90,36 @@ struct vp_reg_val {
};
/**
+ * omap_vdd_dep_volt - Table containing the parent vdd voltage and the
+ * dependent vdd voltage corresponding to it.
+ *
+ * @main_vdd_volt : The main vdd voltage
+ * @dep_vdd_volt : The voltage at which the dependent vdd should be
+ * when the main vdd is at <main_vdd_volt> voltage
+ */
+struct omap_vdd_dep_volt {
+ u32 main_vdd_volt;
+ u32 dep_vdd_volt;
+};
+
+/**
+ * omap_vdd_dep_info - Dependent vdd info
+ *
+ * @name : Dependent vdd name
+ * @voltdm : Dependent vdd pointer
+ * @dep_table : Table containing the dependent vdd voltage
+ * corresponding to every main vdd voltage.
+ * @cur_dep_volt : The voltage to which dependent vdd should be put
+ * to for the current main vdd voltage.
+ */
+struct omap_vdd_dep_info{
+ char *name;
+ struct voltagedomain *voltdm;
+ struct omap_vdd_dep_volt *dep_table;
+ unsigned long cur_dep_volt;
+};
+
+/**
* struct omap_vdd_user_list - The per vdd user list
*
* @dev: The device asking for the vdd to be set at a particular
@@ -135,12 +165,14 @@ struct omap_vdd_info{
struct vp_reg_offs vp_offs;
struct vp_reg_val vp_reg;
struct voltagedomain voltdm;
+ struct omap_vdd_dep_info *dep_vdd_info;
struct dentry *debug_dir;
spinlock_t user_lock;
struct plist_head user_list;
struct mutex scaling_mutex;
struct list_head dev_list;
int volt_data_count;
+ int nr_dep_vdd;
u32 nominal_volt;
u32 curr_volt;
u8 cmdval_reg;
@@ -1139,6 +1171,80 @@ static int vp_forceupdate_scale_voltage(struct omap_vdd_info *vdd,
return 0;
}
+static int calc_dep_vdd_volt(struct device *dev,
+ struct omap_vdd_info *main_vdd, unsigned long main_volt)
+{
+ struct omap_vdd_dep_info *dep_vdds;
+ int i, ret = 0;
+
+ if (!main_vdd->dep_vdd_info) {
+ pr_debug("%s: No dependent VDD's for vdd_%s\n",
+ __func__, main_vdd->voltdm.name);
+ return 0;
+ }
+
+ dep_vdds = main_vdd->dep_vdd_info;
+
+ for (i = 0; i < main_vdd->nr_dep_vdd; i++) {
+ struct omap_vdd_dep_volt *volt_table = dep_vdds[i].dep_table;
+ int nr_volt = 0;
+ unsigned long dep_volt = 0, act_volt = 0;
+
+ while (volt_table[nr_volt].main_vdd_volt != 0) {
+ if (volt_table[nr_volt].main_vdd_volt == main_volt) {
+ dep_volt = volt_table[nr_volt].dep_vdd_volt;
+ break;
+ }
+ nr_volt++;
+ }
+ if (!dep_volt) {
+ pr_warning("%s: Not able to find a matching volt for"
+ "vdd_%s corresponding to vdd_%s %ld volt\n",
+ __func__, dep_vdds[i].name,
+ main_vdd->voltdm.name, main_volt);
+ ret = -EINVAL;
+ continue;
+ }
+
+ if (!dep_vdds[i].voltdm)
+ dep_vdds[i].voltdm =
+ omap_voltage_domain_lookup(dep_vdds[i].name);
+
+ act_volt = dep_volt;
+
+ /* See if dep_volt is possible for the vdd*/
+ ret = omap_voltage_add_request(dep_vdds[i].voltdm, dev,
+ &act_volt);
+
+ /*
+ * Currently we do not bother if the dep volt and act volt are
+ * different. We could add a check if needed.
+ */
+ dep_vdds[i].cur_dep_volt = act_volt;
+ }
+
+ return ret;
+}
+
+static int scale_dep_vdd(struct omap_vdd_info *main_vdd)
+{
+ struct omap_vdd_dep_info *dep_vdds;
+ int i;
+
+ if (!main_vdd->dep_vdd_info) {
+ pr_debug("%s: No dependent VDD's for vdd_%s\n",
+ __func__, main_vdd->voltdm.name);
+ return 0;
+ }
+
+ dep_vdds = main_vdd->dep_vdd_info;
+
+ for (i = 0; i < main_vdd->nr_dep_vdd; i++)
+ omap_voltage_scale(dep_vdds[i].voltdm,
+ dep_vdds[i].cur_dep_volt);
+ return 0;
+}
+
/* Public functions */
/**
* omap_voltage_get_nom_volt() - Gets the current non-auto-compensated voltage
@@ -1697,6 +1803,8 @@ int omap_voltage_scale(struct voltagedomain *voltdm, unsigned long volt)
int is_volt_scaled = 0;
struct omap_vdd_info *vdd;
struct omap_vdd_dev_list *temp_dev;
+ struct plist_node *node;
+ struct omap_vdd_user_list *user;
if (!voltdm || IS_ERR(voltdm)) {
pr_warning("%s: VDD specified does not exist!\n", __func__);
@@ -1709,6 +1817,17 @@ int omap_voltage_scale(struct voltagedomain *voltdm, unsigned long volt)
curr_volt = omap_voltage_get_nom_volt(voltdm);
+ /* Find the device requesting the voltage scaling */
+ node = plist_first(&vdd->user_list);
+ user = container_of(node, struct omap_vdd_user_list, node);
+
+ /* calculate the voltages for dependent vdd's */
+ if (calc_dep_vdd_volt(user->dev, vdd, volt)) {
+ pr_warning("%s: Error in calculating dependent vdd voltages"
+ "for vdd_%s\n", __func__, voltdm->name);
+ return -EINVAL;
+ }
+
if (curr_volt == volt) {
is_volt_scaled = 1;
} else if (curr_volt < volt) {
@@ -1746,6 +1865,9 @@ int omap_voltage_scale(struct voltagedomain *voltdm, unsigned long volt)
mutex_unlock(&vdd->scaling_mutex);
+ /* Scale dependent vdds */
+ scale_dep_vdd(vdd);
+
return 0;
}
--
1.7.0.4
--
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