cpufreq: db8500: Use armss clk to update frequency

Using the armss clk to update the frequency makes the driver no more
directly dependant on the prmcu API.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

drivers/cpufreq/db8500-cpufreq.c

@@ -14,10 +14,11 @@
 #include <linux/delay.h>
 #include <linux/slab.h>
 #include <linux/platform_device.h>
-#include <linux/mfd/dbx500-prcmu.h>
+#include <linux/clk.h>
 #include <mach/id.h>
 
 static struct cpufreq_frequency_table *freq_table;
+static struct clk *armss_clk;
 
 static struct freq_attr *db8500_cpufreq_attr[] = {
 	&cpufreq_freq_attr_scaling_available_freqs,
@@ -58,9 +59,9 @@ static int db8500_cpufreq_target(struct cpufreq_policy *policy,
 	for_each_cpu(freqs.cpu, policy->cpus)
 		cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
 
-	/* request the PRCM unit for opp change */
-	if (prcmu_set_arm_opp(freq_table[idx].index)) {
-		pr_err("db8500-cpufreq:  Failed to set OPP level\n");
+	/* update armss clk frequency */
+	if (clk_set_rate(armss_clk, freq_table[idx].frequency * 1000)) {
+		pr_err("db8500-cpufreq: Failed to update armss clk\n");
 		return -EINVAL;
 	}
 
@@ -74,16 +75,16 @@ static int db8500_cpufreq_target(struct cpufreq_policy *policy,
 static unsigned int db8500_cpufreq_getspeed(unsigned int cpu)
 {
 	int i = 0;
-	/* request the prcm to get the current ARM opp */
-	int opp = prcmu_get_arm_opp();
+	unsigned long freq = clk_get_rate(armss_clk) / 1000;
 
 	while (freq_table[i].frequency != CPUFREQ_TABLE_END) {
-		if (opp == freq_table[i].index)
+		if (freq <= freq_table[i].frequency)
 			return freq_table[i].frequency;
 		i++;
 	}
 
-	/* We could not find a corresponding opp frequency. */
+	/* We could not find a corresponding frequency. */
+	pr_err("db8500-cpufreq: Failed to find cpufreq speed\n");
 	return 0;
 }
 
@@ -92,6 +93,12 @@ static int __cpuinit db8500_cpufreq_init(struct cpufreq_policy *policy)
 	int i = 0;
 	int res;
 
+	armss_clk = clk_get(NULL, "armss");
+	if (IS_ERR(armss_clk)) {
+		pr_err("db8500-cpufreq : Failed to get armss clk\n");
+		return PTR_ERR(armss_clk);
+	}
+
 	pr_info("db8500-cpufreq : Available frequencies:\n");
 	while (freq_table[i].frequency != CPUFREQ_TABLE_END) {
 		pr_info("  %d Mhz\n", freq_table[i].frequency/1000);
@@ -104,6 +111,7 @@ static int __cpuinit db8500_cpufreq_init(struct cpufreq_policy *policy)
 		cpufreq_frequency_table_get_attr(freq_table, policy->cpu);
 	else {
 		pr_err("db8500-cpufreq : Failed to read policy table\n");
+		clk_put(armss_clk);
 		return res;
 	}