[PATCHv6 03/11] ARM: OMAP3+: voltage: add support for voltagedomain usecounts
Tero Kristo
t-kristo at ti.com
Tue Sep 25 12:05:34 EDT 2012
These are updated based on powerdomain usecounts. Also added support
for voltdm->sleep and voltdm->wakeup calls that will be invoked once
voltagedomain enters sleep or wakes up based on usecount numbers. These
will be used for controlling voltage scaling functionality.
Signed-off-by: Tero Kristo <t-kristo at ti.com>
Cc: Paul Walmsley <paul at pwsan.com>
Cc: Kevin Hilman <khilman at ti.com>
---
arch/arm/mach-omap2/powerdomain.c | 17 +++++++++-
arch/arm/mach-omap2/voltage.c | 65 +++++++++++++++++++++++++++++++++++++
arch/arm/mach-omap2/voltage.h | 13 +++++++
3 files changed, 94 insertions(+), 1 deletions(-)
diff --git a/arch/arm/mach-omap2/powerdomain.c b/arch/arm/mach-omap2/powerdomain.c
index ba49029..abc50c2 100644
--- a/arch/arm/mach-omap2/powerdomain.c
+++ b/arch/arm/mach-omap2/powerdomain.c
@@ -1475,10 +1475,17 @@ int pwrdm_state_switch(struct powerdomain *pwrdm)
*/
void pwrdm_clkdm_enable(struct powerdomain *pwrdm)
{
+ unsigned long flags;
+
if (!pwrdm)
return;
- atomic_inc(&pwrdm->usecount);
+ spin_lock_irqsave(&pwrdm->lock, flags);
+
+ if (atomic_inc_return(&pwrdm->usecount) == 1)
+ voltdm_pwrdm_enable(pwrdm->voltdm.ptr);
+
+ spin_unlock_irqrestore(&pwrdm->lock, flags);
}
/**
@@ -1492,12 +1499,20 @@ void pwrdm_clkdm_enable(struct powerdomain *pwrdm)
void pwrdm_clkdm_disable(struct powerdomain *pwrdm)
{
int val;
+ unsigned long flags;
if (!pwrdm)
return;
+ spin_lock_irqsave(&pwrdm->lock, flags);
+
val = atomic_dec_return(&pwrdm->usecount);
+ if (!val)
+ voltdm_pwrdm_disable(pwrdm->voltdm.ptr);
+
+ spin_unlock_irqrestore(&pwrdm->lock, flags);
+
WARN_ON(val < 0);
}
diff --git a/arch/arm/mach-omap2/voltage.c b/arch/arm/mach-omap2/voltage.c
index 4dc60e8..0fc2a25 100644
--- a/arch/arm/mach-omap2/voltage.c
+++ b/arch/arm/mach-omap2/voltage.c
@@ -340,6 +340,70 @@ int voltdm_add_pwrdm(struct voltagedomain *voltdm, struct powerdomain *pwrdm)
}
/**
+ * voltdm_pwrdm_enable - increase usecount for a voltagedomain
+ * @voltdm: struct voltagedomain * to increase count for
+ *
+ * Increases usecount for a given voltagedomain. If the usecount reaches
+ * 1, the domain is awakened from idle and the function will call the
+ * voltagedomain->wakeup callback for this domain.
+ */
+void voltdm_pwrdm_enable(struct voltagedomain *voltdm)
+{
+ unsigned long flags;
+
+ if (!voltdm)
+ return;
+
+ spin_lock_irqsave(&voltdm->lock, flags);
+
+ if (atomic_inc_return(&voltdm->usecount) == 1 && voltdm->wakeup)
+ voltdm->wakeup(voltdm);
+
+ spin_unlock_irqrestore(&voltdm->lock, flags);
+}
+
+/**
+ * voltdm_pwrdm_disable - decrease usecount for a voltagedomain
+ * @voltdm: struct voltagedomain * to decrease count for
+ *
+ * Decreases the usecount for a given voltagedomain. If the usecount
+ * reaches zero, the domain can idle and the function will call the
+ * voltagedomain->sleep callback, and calculate the overall target
+ * state for the voltagedomain.
+ */
+void voltdm_pwrdm_disable(struct voltagedomain *voltdm)
+{
+ u8 target_state = PWRDM_POWER_OFF;
+ int state;
+ struct powerdomain *pwrdm;
+ int val;
+ unsigned long flags;
+
+ if (!voltdm)
+ return;
+
+ spin_lock_irqsave(&voltdm->lock, flags);
+
+ val = atomic_dec_return(&voltdm->usecount);
+
+ WARN_ON(val < 0);
+
+ if (val == 0) {
+ /* Determine target state for voltdm */
+ list_for_each_entry(pwrdm, &voltdm->pwrdm_list, voltdm_node) {
+ state = pwrdm_read_next_pwrst(pwrdm);
+ if (state > target_state)
+ target_state = state;
+ }
+ voltdm->target_state = target_state;
+ if (voltdm->sleep)
+ voltdm->sleep(voltdm);
+ }
+
+ spin_unlock_irqrestore(&voltdm->lock, flags);
+}
+
+/**
* voltdm_for_each_pwrdm - call function for each pwrdm in a voltdm
* @voltdm: struct voltagedomain * to iterate over
* @fn: callback function *
@@ -402,6 +466,7 @@ static int _voltdm_register(struct voltagedomain *voltdm)
INIT_LIST_HEAD(&voltdm->pwrdm_list);
list_add(&voltdm->node, &voltdm_list);
+ spin_lock_init(&voltdm->lock);
pr_debug("voltagedomain: registered %s\n", voltdm->name);
return 0;
diff --git a/arch/arm/mach-omap2/voltage.h b/arch/arm/mach-omap2/voltage.h
index 0ac2caf..7f4f99d 100644
--- a/arch/arm/mach-omap2/voltage.h
+++ b/arch/arm/mach-omap2/voltage.h
@@ -15,6 +15,7 @@
#define __ARCH_ARM_MACH_OMAP2_VOLTAGE_H
#include <linux/err.h>
+#include <linux/spinlock.h>
#include <plat/voltage.h>
@@ -56,10 +57,14 @@ struct omap_vfsm_instance {
* @pwrdm_list: list_head linking all powerdomains in this voltagedomain
* @vc: pointer to VC channel associated with this voltagedomain
* @vp: pointer to VP associated with this voltagedomain
+ * @usecount: number of users for this voltagedomain
+ * @target_state: calculated target state for the children of this domain
* @read: read a VC/VP register
* @write: write a VC/VP register
* @read: read-modify-write a VC/VP register
* @sys_clk: system clock name/frequency, used for various timing calculations
+ * @sleep: function to call once the domain enters idle
+ * @wakeup: function to call once the domain wakes up from idle
* @scale: function used to scale the voltage of the voltagedomain
* @nominal_volt: current nominal voltage for this voltage domain
* @volt_data: voltage table having the distinct voltages supported
@@ -75,6 +80,9 @@ struct voltagedomain {
struct omap_vp_instance *vp;
struct omap_voltdm_pmic *pmic;
+ atomic_t usecount;
+ u8 target_state;
+
/* VC/VP register access functions: SoC specific */
u32 (*read) (u8 offset);
void (*write) (u32 val, u8 offset);
@@ -85,11 +93,14 @@ struct voltagedomain {
u32 rate;
} sys_clk;
+ void (*sleep) (struct voltagedomain *voltdm);
+ void (*wakeup) (struct voltagedomain *voltdm);
int (*scale) (struct voltagedomain *voltdm,
unsigned long target_volt);
u32 nominal_volt;
struct omap_volt_data *volt_data;
+ spinlock_t lock;
};
/**
@@ -145,6 +156,8 @@ extern void omap44xx_voltagedomains_init(void);
struct voltagedomain *voltdm_lookup(const char *name);
void voltdm_init(struct voltagedomain **voltdm_list);
int voltdm_add_pwrdm(struct voltagedomain *voltdm, struct powerdomain *pwrdm);
+void voltdm_pwrdm_enable(struct voltagedomain *voltdm);
+void voltdm_pwrdm_disable(struct voltagedomain *voltdm);
int voltdm_for_each(int (*fn)(struct voltagedomain *voltdm, void *user),
void *user);
int voltdm_for_each_pwrdm(struct voltagedomain *voltdm,
--
1.7.4.1
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