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[RFC,1/7] OMAP: Introduce a user list for each voltage domain instance in the voltage driver.

Message ID 1278065909-32148-2-git-send-email-thara@ti.com (mailing list archive)
State New, archived
Headers show

Commit Message

Thara Gopinath July 2, 2010, 10:18 a.m. UTC
None
diff mbox

Patch

diff --git a/arch/arm/mach-omap2/voltage.c b/arch/arm/mach-omap2/voltage.c
index 30f1770..a2f30a4 100644
--- a/arch/arm/mach-omap2/voltage.c
+++ b/arch/arm/mach-omap2/voltage.c
@@ -24,6 +24,9 @@ 
 #include <linux/clk.h>
 #include <linux/err.h>
 #include <linux/debugfs.h>
+#include <linux/spinlock.h>
+#include <linux/plist.h>
+#include <linux/slab.h>
 
 #include <plat/omap-pm.h>
 #include <plat/omap34xx.h>
@@ -93,6 +96,20 @@  struct vp_reg_val {
 };
 
 /**
+ * omap_vdd_user_list	- The per vdd user list
+ *
+ * @dev		: The device asking for the vdd to be set at a particular
+ *		  voltage
+ * @node	: The list head entry
+ * @volt	: The voltage requested by the device <dev>
+ */
+struct omap_vdd_user_list {
+	struct device *dev;
+	struct plist_node node;
+	u32 volt;
+};
+
+/**
  * omap_vdd_info - Per Voltage Domain info
  *
  * @volt_data		: voltage table having the distinct voltages supported
@@ -103,6 +120,9 @@  struct vp_reg_val {
  *			  vp registers
  * @volt_clk		: the clock associated with the vdd.
  * @opp_dev		: the 'struct device' associated with this vdd.
+ * @user_lock		: the lock to be used by the plist user_list
+ * @user_list		: the list head maintaining the various users
+ *			  of this vdd with the voltage requested by each user.
  * @volt_data_count	: Number of distinct voltages supported by this vdd.
  * @nominal_volt	: Nominal voltaged for this vdd.
  * cmdval_reg		: Voltage controller cmdval register.
@@ -115,6 +135,8 @@  struct omap_vdd_info{
 	struct clk *volt_clk;
 	struct device *opp_dev;
 	struct omap_volt_domain volt_domain;
+	spinlock_t user_lock;
+	struct plist_head user_list;
 	int volt_data_count;
 	unsigned long nominal_volt;
 	u8 cmdval_reg;
@@ -361,6 +383,10 @@  static void __init omap3_vdd_data_configure(struct omap_vdd_info *vdd)
 	struct clk *sys_ck;
 	u32 sys_clk_speed, timeout_val, waittime;
 
+	/* Init the plist */
+	spin_lock_init(&vdd->user_lock);
+	plist_head_init(&vdd->user_list, &vdd->user_lock);
+
 	if (!strcmp(vdd->volt_domain.name, "mpu")) {
 		if (cpu_is_omap3630()) {
 			vdd->vp_reg.vlimitto_vddmin =
@@ -881,6 +907,63 @@  unsigned long omap_voltageprocessor_get_curr_volt(
 }
 
 /**
+ * omap_voltage_get_final : API to keep track of various requests to
+ *			    scale the VDD and returns the best possible
+ *			    voltage the VDD can be put to.
+ * @volt_domain: pointer to the voltage domain.
+ * @dev : the device pointer.
+ * @volt : the voltage which is requested by the device.
+ *
+ * This API is to be called before the actual voltage scaling is
+ * done to determine what is the best possible voltage the VDD can
+ * be put to. This API adds the device <dev> in the user list of the
+ * vdd <volt_domain> with <volt> as the requested voltage. The user list
+ * is a plist with the priority element absolute voltage values.
+ * The API then finds the maximum of all the requested voltages for
+ * the VDD and returns it back through <volt> pointer itself.
+ * Returns error value in case of any errors.
+ */
+int omap_volt_get_final(struct omap_volt_domain *volt_domain,
+		struct device *dev, unsigned long *volt)
+{
+	struct omap_vdd_info *vdd;
+	struct omap_vdd_user_list *user;
+	struct plist_node *node;
+	int found = 0;
+
+	if (!volt_domain || IS_ERR(volt_domain)) {
+		pr_warning("%s: VDD specified does not exist!\n", __func__);
+		return -EINVAL;
+	}
+
+	vdd = container_of(volt_domain, struct omap_vdd_info, volt_domain);
+
+	plist_for_each_entry(user, &vdd->user_list, node) {
+		if (user->dev == dev) {
+			found = 1;
+			break;
+		}
+	}
+
+	if (!found) {
+		user = kzalloc(sizeof(struct omap_vdd_user_list), GFP_KERNEL);
+		if (!user) {
+			pr_err("%s: Unable to creat a new user for vdd_%s\n",
+				__func__, volt_domain->name);
+			return -ENOMEM;
+		}
+		user->dev = dev;
+		plist_node_init(&user->node, *volt);
+		plist_add(&user->node, &vdd->user_list);
+	}
+
+	user->node.prio = *volt;
+	node = plist_first(&vdd->user_list);
+	*volt = node->prio;
+	return 0;
+}
+
+/**
  * omap_voltageprocessor_enable : API to enable a particular VP
  * @volt_domain: pointer to the VDD whose VP is to be enabled.
  *
diff --git a/arch/arm/plat-omap/include/plat/voltage.h b/arch/arm/plat-omap/include/plat/voltage.h
index b7ac318..bc1e4d3 100644
--- a/arch/arm/plat-omap/include/plat/voltage.h
+++ b/arch/arm/plat-omap/include/plat/voltage.h
@@ -128,6 +128,8 @@  int omap_get_voltage_table(struct omap_volt_domain *volt_domain,
 struct omap_volt_data *omap_get_volt_data(
 		struct omap_volt_domain *volt_domain, unsigned long volt);
 unsigned long get_curr_voltage(struct omap_volt_domain *volt_domain);
+int omap_volt_get_final(struct omap_volt_domain *volt_domain,
+		struct device *dev, unsigned long *volt);
 #ifdef CONFIG_PM
 void omap_voltage_init_vc(struct omap_volt_vc_data *setup_vc);
 #else