[PATCH] OMAP3: PM: Scale VDD2 OPP for VDD1 OPP3 and higher

["Rajendra Nayak" <rnayak@ti.com>]

This patch implements an implicit/internal constraint
of 100Mhz for L3 bus while the VDD1 OPP is OPP3 or higher.
The patch also removes the usage of bus_throughput_db
from SRF.
Applies on the latest pm branch.

Signed-off-by: Rajendra Nayak <rnayak@ti.com>
---
 arch/arm/mach-omap2/pm.c           |    6 +++++-
 arch/arm/mach-omap2/resource34xx.c |   37 ++++++++++++++++++++++++++++---------
 arch/arm/mach-omap2/resource34xx.h |   13 -------------
 3 files changed, 33 insertions(+), 23 deletions(-)

Index: linux-omap-2.6/arch/arm/mach-omap2/resource34xx.c
===================================================================
--- linux-omap-2.6.orig/arch/arm/mach-omap2/resource34xx.c	2008-12-16 11:11:28.000000000 +0530
+++ linux-omap-2.6/arch/arm/mach-omap2/resource34xx.c	2008-12-16 16:04:43.017689014 +0530
@@ -146,7 +146,7 @@ void init_opp(struct shared_resource *re
 	resp->no_of_users = 0;
 
 	if (!mpu_opps || !dsp_opps || !l3_opps)
-		return 0;
+		return;
 
 	/* Initialize the current level of the OPP resource
 	* to the  opp set by u-boot.
@@ -161,11 +161,12 @@ void init_opp(struct shared_resource *re
 	return;
 }
 
+static struct device vdd2_dev;
+
 int set_opp(struct shared_resource *resp, u32 target_level)
 {
-	unsigned long mpu_freq, mpu_old_freq, l3_freq, tput, t_opp;
+	unsigned long mpu_freq, mpu_old_freq, l3_freq, req_l3_freq, tput, t_opp;
 	int ind;
-	struct bus_throughput_db *tput_db;
 	struct cpufreq_freqs freqs_notify;
 
 	if (resp->curr_level == target_level)
@@ -188,6 +189,14 @@ int set_opp(struct shared_resource *resp
 #endif
 		t_opp = ID_VDD(PRCM_VDD1) |
 			ID_OPP_NO(mpu_opps[target_level].opp_id);
+
+		/* For VDD1 OPP3 and above, make sure the interconnect
+		 * is at 100Mhz or above.
+		 * throughput in KiB/s for 100 Mhz = 100 * 1000 * 4.
+		 */
+		if (mpu_opps[target_level].opp_id >= 3)
+			resource_request("vdd2_opp", &vdd2_dev, 400000);
+
 		if (resp->curr_level > target_level) {
 			/* Scale Frequency and then voltage */
 			clk_set_rate(vdd1_clk, mpu_freq);
@@ -203,22 +212,32 @@ int set_opp(struct shared_resource *resp
 #endif
 			clk_set_rate(vdd1_clk, mpu_freq);
 		}
+
+		/* Release the VDD2/interconnect constraint */
+		if (mpu_opps[target_level].opp_id < 3)
+			resource_release("vdd2_opp", &vdd2_dev);
+
 		resp->curr_level = curr_vdd1_prcm_set->opp_id;
 #ifdef CONFIG_CPU_FREQ
 		/* Send a post notification to CPUFreq */
 		cpufreq_notify_transition(&freqs_notify, CPUFREQ_POSTCHANGE);
 #endif
 	} else if (strcmp(resp->name, "vdd2_opp") == 0) {
-		tput_db = resp->resource_data;
 		tput = target_level;
-		/* using the throughput db map to the appropriate L3 Freq */
-		for (ind = 1; ind < MAX_VDD2_OPP; ind++)
-			if (tput_db->throughput[ind] > tput)
+
+		/* Convert the tput in KiB/s to Bus frequency in Mhz*/
+		req_l3_freq = (tput * 1000)/4;
+
+		for (ind = 2; ind <= MAX_VDD2_OPP; ind++) {
+			if ((l3_opps + ind)->rate >= req_l3_freq) {
 				target_level = ind;
+				break;
+			}
+		}
 
 		/* Set the highest OPP possible */
-		if (ind == MAX_VDD2_OPP)
-			target_level = ind-1;
+		if (ind > MAX_VDD2_OPP)
+			target_level = MAX_VDD2_OPP;
 
 		if (resp->curr_level == target_level)
 			return 0;
Index: linux-omap-2.6/arch/arm/mach-omap2/pm.c
===================================================================
--- linux-omap-2.6.orig/arch/arm/mach-omap2/pm.c	2008-12-16 10:35:55.000000000 +0530
+++ linux-omap-2.6/arch/arm/mach-omap2/pm.c	2008-12-16 16:01:48.580075608 +0530
@@ -34,6 +34,7 @@
 #include <mach/powerdomain.h>
 #include <mach/omapdev.h>
 #include <mach/resource.h>
+#include <mach/omap-pm.h>
 
 #include "prm-regbits-34xx.h"
 #include "pm.h"
@@ -136,6 +137,7 @@ static ssize_t vdd_opp_store(struct kobj
 			  const char *buf, size_t n)
 {
 	unsigned short value;
+	unsigned long bus_tput;
 
 	if (sscanf(buf, "%hu", &value) != 1)
 		return -EINVAL;
@@ -151,7 +153,9 @@ static ssize_t vdd_opp_store(struct kobj
 			printk(KERN_ERR "vdd_opp_store: Invalid value\n");
 			return -EINVAL;
 		}
-		resource_request("vdd2_opp", &dummy_sysfs_dev, value);
+		/* Convert OPP's requested to appr. bus throughtput in KiB/s */
+		bus_tput = ((l3_opps + value)->rate/1000) * 4;
+		resource_request("vdd2_opp", &dummy_sysfs_dev, bus_tput);
 	} else {
 		return -EINVAL;
 	}
Index: linux-omap-2.6/arch/arm/mach-omap2/resource34xx.h
===================================================================
--- linux-omap-2.6.orig/arch/arm/mach-omap2/resource34xx.h	2008-12-16 10:35:55.000000000 +0530
+++ linux-omap-2.6/arch/arm/mach-omap2/resource34xx.h	2008-12-16 15:28:22.341172791 +0530
@@ -238,11 +238,6 @@ void init_freq(struct shared_resource *r
 int set_freq(struct shared_resource *resp, u32 target_level);
 int validate_freq(struct shared_resource *resp, u32 target_level);
 
-struct bus_throughput_db {
-	/* Throughput for each OPP/Freq of the bus */
-	unsigned long throughput[3];
-};
-
 static struct shared_resource_ops opp_res_ops = {
 	.init           = init_opp,
 	.change_level   = set_opp,
@@ -255,17 +250,9 @@ static struct shared_resource vdd1_opp =
 	.ops            = &opp_res_ops,
 };
 
-/* Throughput in KiB/s */
-static struct bus_throughput_db l3_throughput_db = {
-	.throughput[0] = 0,
-	.throughput[1] = 2656000,
-	.throughput[2] = 5312000,
-};
-
 static struct shared_resource vdd2_opp = {
 	.name           = "vdd2_opp",
 	.omap_chip      = OMAP_CHIP_INIT(CHIP_IS_OMAP3430),
-	.resource_data  = &l3_throughput_db,
 	.ops            = &opp_res_ops,
 };