cpufreq: update DB8500 cpufreq driver

This updates the ux500 cpufreq driver to the new interface from the
updated DB8500 PRCMU

Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Dave Jones <davej@redhat.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 63 insertions, 104 deletions

diff --git a/drivers/cpufreq/db8500-cpufreq.c b/drivers/cpufreq/db8500-cpufreq.c
index d196939fcdb9..d90456a809f9 100644
--- a/drivers/cpufreq/db8500-cpufreq.c
+++ b/drivers/cpufreq/db8500-cpufreq.c
@@ -1,134 +1,118 @@
 /*
- * CPU frequency scaling for u8500
- * Inspired by linux/arch/arm/mach-davinci/cpufreq.c
- *
  * Copyright (C) STMicroelectronics 2009
  * Copyright (C) ST-Ericsson SA 2010
  *
  * License Terms: GNU General Public License v2
- *
  * Author: Sundar Iyer <sundar.iyer@stericsson.com>
  * Author: Martin Persson <martin.persson@stericsson.com>
  * Author: Jonas Aaberg <jonas.aberg@stericsson.com>
  *
  */
-
-#include <linux/platform_device.h>
 #include <linux/kernel.h>
 #include <linux/cpufreq.h>
 #include <linux/delay.h>
+#include <linux/slab.h>
 #include <linux/mfd/db8500-prcmu.h>
-
-#include <mach/hardware.h>
-
-#define DRIVER_NAME "cpufreq-u8500"
-#define CPUFREQ_NAME "u8500"
-
-static struct device *dev;
+#include <mach/id.h>
 
 static struct cpufreq_frequency_table freq_table[] = {
         [0] = {
                 .index = 0,
-                .frequency = 200000,
+                .frequency = 300000,
         },
         [1] = {
                 .index = 1,
-                .frequency = 300000,
+                .frequency = 600000,
         },
         [2] = {
+                /* Used for MAX_OPP, if available */
                 .index = 2,
-                .frequency = 600000,
+                .frequency = CPUFREQ_TABLE_END,
         },
         [3] = {
-                /* Used for CPU_OPP_MAX, if available */
                 .index = 3,
                 .frequency = CPUFREQ_TABLE_END,
         },
-        [4] = {
-                .index = 4,
-                .frequency = CPUFREQ_TABLE_END,
-        },
 };
 
-static enum prcmu_cpu_opp index2opp[] = {
-        CPU_OPP_EXT_CLK,
-        CPU_OPP_50,
-        CPU_OPP_100,
-        CPU_OPP_MAX
+static enum arm_opp idx2opp[] = {
+        ARM_50_OPP,
+        ARM_100_OPP,
+        ARM_MAX_OPP
+};
+
+static struct freq_attr *db8500_cpufreq_attr[] = {
+        &cpufreq_freq_attr_scaling_available_freqs,
+        NULL,
 };
 
-static int u8500_cpufreq_verify_speed(struct cpufreq_policy *policy)
+static int db8500_cpufreq_verify_speed(struct cpufreq_policy *policy)
 {
         return cpufreq_frequency_table_verify(policy, freq_table);
 }
 
-static int u8500_cpufreq_target(struct cpufreq_policy *policy,
+static int db8500_cpufreq_target(struct cpufreq_policy *policy,
                                 unsigned int target_freq,
                                 unsigned int relation)
 {
         struct cpufreq_freqs freqs;
-        unsigned int index;
-        int ret = 0;
+        unsigned int idx;
 
-        /*
-         * Ensure desired rate is within allowed range.  Some govenors
-         * (ondemand) will just pass target_freq=0 to get the minimum.
-         */
+        /* scale the target frequency to one of the extremes supported */
         if (target_freq < policy->cpuinfo.min_freq)
                 target_freq = policy->cpuinfo.min_freq;
         if (target_freq > policy->cpuinfo.max_freq)
                 target_freq = policy->cpuinfo.max_freq;
 
-        ret = cpufreq_frequency_table_target(policy, freq_table,
-                                             target_freq, relation, &index);
-        if (ret < 0) {
-                dev_err(dev, "Could not look up next frequency\n");
-                return ret;
+        /* Lookup the next frequency */
+        if (cpufreq_frequency_table_target
+            (policy, freq_table, target_freq, relation, &idx)) {
+                return -EINVAL;
         }
 
         freqs.old = policy->cur;
-        freqs.new = freq_table[index].frequency;
+        freqs.new = freq_table[idx].frequency;
         freqs.cpu = policy->cpu;
 
-        if (freqs.old == freqs.new) {
-                dev_dbg(dev, "Current and target frequencies are equal\n");
+        if (freqs.old == freqs.new)
                 return 0;
-        }
 
-        dev_dbg(dev, "transition: %u --> %u\n", freqs.old, freqs.new);
+        /* pre-change notification */
         cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
 
-        ret = prcmu_set_cpu_opp(index2opp[index]);
-        if (ret < 0) {
-                dev_err(dev, "Failed to set OPP level\n");
-                return ret;
+        /* request the PRCM unit for opp change */
+        if (prcmu_set_arm_opp(idx2opp[idx])) {
+                pr_err("db8500-cpufreq:  Failed to set OPP level\n");
+                return -EINVAL;
         }
 
+        /* post change notification */
         cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
 
-        return ret;
+        return 0;
 }
 
-static unsigned int u8500_cpufreq_getspeed(unsigned int cpu)
+static unsigned int db8500_cpufreq_getspeed(unsigned int cpu)
 {
         int i;
-
-        for (i = 0; prcmu_get_cpu_opp() != index2opp[i]; i++)
+        /* request the prcm to get the current ARM opp */
+        for (i = 0; prcmu_get_arm_opp() != idx2opp[i]; i++)
                 ;
         return freq_table[i].frequency;
 }
 
-static int __cpuinit u8500_cpu_init(struct cpufreq_policy *policy)
+static int __cpuinit db8500_cpufreq_init(struct cpufreq_policy *policy)
 {
         int res;
+        int i;
 
-        BUILD_BUG_ON(ARRAY_SIZE(index2opp) + 1 != ARRAY_SIZE(freq_table));
+        BUILD_BUG_ON(ARRAY_SIZE(idx2opp) + 1 != ARRAY_SIZE(freq_table));
 
-        if (cpu_is_u8500v2()) {
-                freq_table[1].frequency = 400000;
-                freq_table[2].frequency = 800000;
+        if (cpu_is_u8500v2() && !prcmu_is_u8400()) {
+                freq_table[0].frequency = 400000;
+                freq_table[1].frequency = 800000;
                 if (prcmu_has_arm_maxopp())
-                        freq_table[3].frequency = 1000000;
+                        freq_table[2].frequency = 1000000;
         }
 
         /* get policy fields based on the table */
@@ -136,13 +120,17 @@ static int __cpuinit u8500_cpu_init(struct cpufreq_policy *policy)
         if (!res)
                 cpufreq_frequency_table_get_attr(freq_table, policy->cpu);
         else {
-                dev_err(dev, "u8500-cpufreq : Failed to read policy table\n");
+                pr_err("db8500-cpufreq : Failed to read policy table\n");
                 return res;
         }
 
         policy->min = policy->cpuinfo.min_freq;
         policy->max = policy->cpuinfo.max_freq;
-        policy->cur = u8500_cpufreq_getspeed(policy->cpu);
+        policy->cur = db8500_cpufreq_getspeed(policy->cpu);
+
+        for (i = 0; freq_table[i].frequency != policy->cur; i++)
+                ;
+
         policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
 
         /*
@@ -150,61 +138,32 @@ static int __cpuinit u8500_cpu_init(struct cpufreq_policy *policy)
          *         function with no/some/all drivers in the notification
          *         list.
          */
-        policy->cpuinfo.transition_latency = 200 * 1000; /* in ns */
+        policy->cpuinfo.transition_latency = 20 * 1000; /* in ns */
 
         /* policy sharing between dual CPUs */
         cpumask_copy(policy->cpus, &cpu_present_map);
 
         policy->shared_type = CPUFREQ_SHARED_TYPE_ALL;
 
-        return res;
-}
-
-static struct freq_attr *u8500_cpufreq_attr[] = {
-        &cpufreq_freq_attr_scaling_available_freqs,
-        NULL,
-};
-static int u8500_cpu_exit(struct cpufreq_policy *policy)
-{
-        cpufreq_frequency_table_put_attr(policy->cpu);
         return 0;
 }
 
-static struct cpufreq_driver u8500_driver = {
-        .owner = THIS_MODULE,
-        .flags = CPUFREQ_STICKY,
-        .verify = u8500_cpufreq_verify_speed,
-        .target = u8500_cpufreq_target,
-        .get = u8500_cpufreq_getspeed,
-        .init = u8500_cpu_init,
-        .exit = u8500_cpu_exit,
-        .name = CPUFREQ_NAME,
-        .attr = u8500_cpufreq_attr,
+static struct cpufreq_driver db8500_cpufreq_driver = {
+        .flags  = CPUFREQ_STICKY,
+        .verify = db8500_cpufreq_verify_speed,
+        .target = db8500_cpufreq_target,
+        .get    = db8500_cpufreq_getspeed,
+        .init   = db8500_cpufreq_init,
+        .name   = "DB8500",
+        .attr   = db8500_cpufreq_attr,
 };
 
-static int __init u8500_cpufreq_probe(struct platform_device *pdev)
+static int __init db8500_cpufreq_register(void)
 {
-        dev = &pdev->dev;
-        return cpufreq_register_driver(&u8500_driver);
-}
-
-static int __exit u8500_cpufreq_remove(struct platform_device *pdev)
-{
-        return cpufreq_unregister_driver(&u8500_driver);
-}
+        if (!cpu_is_u8500v20_or_later())
+                return -ENODEV;
 
-static struct platform_driver u8500_cpufreq_driver = {
-        .driver = {
-                .name    = DRIVER_NAME,
-                .owner   = THIS_MODULE,
-        },
-        .remove = __exit_p(u8500_cpufreq_remove),
-};
-
-static int __init u8500_cpufreq_init(void)
-{
-        return platform_driver_probe(&u8500_cpufreq_driver,
-                                     &u8500_cpufreq_probe);
+        pr_info("cpufreq for DB8500 started\n");
+        return cpufreq_register_driver(&db8500_cpufreq_driver);
 }
-
-device_initcall(u8500_cpufreq_init);
+device_initcall(db8500_cpufreq_register);