imx233: always boost in bootloader

Many imx233 targets boot in a very low performance mode, typically cpu and
dram at 24MHz. This results in very slow boots and very unstable USB
bootloader mode. Since cpu frequency scaling is disabled in bootloader in
rockbox, always make the frequency scaling code available and boost at boot
time.

Change-Id: Ie96623c00f7c4cd9a377b84dcb14b772558cfa4d

3 files changed, 14 insertions, 2 deletions

diff --git a/bootloader/imx233.c b/bootloader/imx233.c
index ebd67cea6c..79e5708bad 100644
--- a/bootloader/imx233.c
+++ b/bootloader/imx233.c
@@ -141,6 +141,11 @@ void main(uint32_t arg, uint32_t addr)
     system_init();
     kernel_init();
 
+    /* some ixm233 targets needs this because the cpu and/or memory is clocked
+     * at 24MHz, resulting in terribly slow boots and unusable usb mode.
+     * While we are at it, clock at maximum speed to minimise boot time. */
+    imx233_set_cpu_frequency(CPUFREQ_MAX);
+
     power_init();
     enable_irq();
 
diff --git a/firmware/target/arm/imx233/system-imx233.c b/firmware/target/arm/imx233/system-imx233.c
index 3f751a8aa5..44d6f0e7ad 100644
--- a/firmware/target/arm/imx233/system-imx233.c
+++ b/firmware/target/arm/imx233/system-imx233.c
@@ -192,7 +192,6 @@ void imx233_digctl_set_arm_cache_timings(unsigned timings)
 #endif
 }
 
-#ifdef HAVE_ADJUSTABLE_CPU_FREQ
 struct cpufreq_profile_t
 {
     /* key */
@@ -219,7 +218,7 @@ static struct cpufreq_profile_t cpu_profiles[] =
 
 #define NR_CPU_PROFILES ((int)(sizeof(cpu_profiles)/sizeof(cpu_profiles[0])))
 
-void set_cpu_frequency(long frequency)
+void imx233_set_cpu_frequency(long frequency)
 {
     /* don't change the frequency if it is useless (changes are expensive) */
     if(cpu_frequency == frequency)
@@ -277,6 +276,12 @@ void set_cpu_frequency(long frequency)
     /* update frequency */
     cpu_frequency = frequency;
 }
+
+#ifdef HAVE_ADJUSTABLE_CPU_FREQ
+void set_cpu_frequency(long frequency)
+{
+    return imx233_set_cpu_frequency(frequency);
+}
 #endif
 
 void imx233_enable_usb_controller(bool enable)
diff --git a/firmware/target/arm/imx233/system-target.h b/firmware/target/arm/imx233/system-target.h
index 407369af7e..33e8f12265 100644
--- a/firmware/target/arm/imx233/system-target.h
+++ b/firmware/target/arm/imx233/system-target.h
@@ -53,6 +53,8 @@ void imx233_reset_block(volatile uint32_t *block_reg);
 void power_off(void);
 void imx233_enable_usb_controller(bool enable);
 void imx233_enable_usb_phy(bool enable);
+// NOTE: this is available even if HAVE_ADJUSTABLE_CPU_FREQ is undef
+void imx233_set_cpu_frequency(long frequency);
 
 void udelay(unsigned usecs);