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