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-rw-r--r--target/linux/ramips/patches-3.10/0021-MIPS-ralink-add-cpu-frequency-scaling.patch95
1 files changed, 95 insertions, 0 deletions
diff --git a/target/linux/ramips/patches-3.10/0021-MIPS-ralink-add-cpu-frequency-scaling.patch b/target/linux/ramips/patches-3.10/0021-MIPS-ralink-add-cpu-frequency-scaling.patch
new file mode 100644
index 0000000000..3fb262be87
--- /dev/null
+++ b/target/linux/ramips/patches-3.10/0021-MIPS-ralink-add-cpu-frequency-scaling.patch
@@ -0,0 +1,95 @@
+From f6dc5d40c766e5ff9b18b93a1b6f7a576655f9c4 Mon Sep 17 00:00:00 2001
+From: John Crispin <blogic@openwrt.org>
+Date: Sun, 28 Jul 2013 16:26:41 +0200
+Subject: [PATCH 21/25] MIPS: ralink: add cpu frequency scaling
+
+This feature will break udelay() and cause the delay loop to have longer delays
+when the frequency is scaled causing a performance hit.
+
+Signed-off-by: John Crispin <blogic@openwrt.org>
+---
+ arch/mips/ralink/cevt-rt3352.c | 36 ++++++++++++++++++++++++++++++++++++
+ 1 file changed, 36 insertions(+)
+
+--- a/arch/mips/ralink/cevt-rt3352.c
++++ b/arch/mips/ralink/cevt-rt3352.c
+@@ -29,6 +29,10 @@
+ /* enable the counter */
+ #define CFG_CNT_EN 0x1
+
++/* mt7620 frequency scaling defines */
++#define CLK_LUT_CFG 0x40
++#define SLEEP_EN BIT(31)
++
+ struct systick_device {
+ void __iomem *membase;
+ struct clock_event_device dev;
+@@ -36,6 +40,8 @@ struct systick_device {
+ int freq_scale;
+ };
+
++static void (*systick_freq_scaling)(struct systick_device *sdev, int status);
++
+ static void systick_set_clock_mode(enum clock_event_mode mode,
+ struct clock_event_device *evt);
+
+@@ -87,6 +93,21 @@ static struct irqaction systick_irqactio
+ .dev_id = &systick.dev,
+ };
+
++static inline void mt7620_freq_scaling(struct systick_device *sdev, int status)
++{
++ if (sdev->freq_scale == status)
++ return;
++
++ sdev->freq_scale = status;
++
++ pr_info("%s: %s autosleep mode\n", systick.dev.name,
++ (status) ? ("enable") : ("disable"));
++ if (status)
++ rt_sysc_w32(rt_sysc_r32(CLK_LUT_CFG) | SLEEP_EN, CLK_LUT_CFG);
++ else
++ rt_sysc_w32(rt_sysc_r32(CLK_LUT_CFG) & ~SLEEP_EN, CLK_LUT_CFG);
++}
++
+ static void systick_set_clock_mode(enum clock_event_mode mode,
+ struct clock_event_device *evt)
+ {
+@@ -101,9 +122,13 @@ static void systick_set_clock_mode(enum
+ sdev->irq_requested = 1;
+ iowrite32(CFG_EXT_STK_EN | CFG_CNT_EN,
+ systick.membase + SYSTICK_CONFIG);
++ if (systick_freq_scaling)
++ systick_freq_scaling(sdev, 1);
+ break;
+
+ case CLOCK_EVT_MODE_SHUTDOWN:
++ if (systick_freq_scaling)
++ systick_freq_scaling(sdev, 0);
+ if (sdev->irq_requested)
+ free_irq(systick.dev.irq, &systick_irqaction);
+ sdev->irq_requested = 0;
+@@ -116,12 +141,23 @@ static void systick_set_clock_mode(enum
+ }
+ }
+
++static const struct of_device_id systick_match[] = {
++ { .compatible = "ralink,mt7620-systick", .data = mt7620_freq_scaling},
++ {},
++};
++
+ static void __init ralink_systick_init(struct device_node *np)
+ {
++ const struct of_device_id *match;
++
+ systick.membase = of_iomap(np, 0);
+ if (!systick.membase)
+ return;
+
++ match = of_match_node(systick_match, np);
++ if (match)
++ systick_freq_scaling = match->data;
++
+ systick_irqaction.name = np->name;
+ systick.dev.name = np->name;
+ clockevents_calc_mult_shift(&systick.dev, SYSTICK_FREQ, 60);