--- /dev/null
+From 10cb446ac01be52c49b5143c8601524bc4f53051 Mon Sep 17 00:00:00 2001
+From: John Crispin <blogic@openwrt.org>
+Date: Sun, 14 Jul 2013 23:11:05 +0200
+Subject: [PATCH 22/33] clocksource: MIPS: ralink: add support for systick
+ timer found on newer ralink SoC
+
+Signed-off-by: John Crispin <blogic@openwrt.org>
+---
+ arch/mips/ralink/Kconfig | 2 +
+ arch/mips/ralink/clk.c | 1 +
+ drivers/clocksource/Kconfig | 6 ++
+ drivers/clocksource/Makefile | 1 +
+ drivers/clocksource/cevt-rt3352.c | 162 +++++++++++++++++++++++++++++++++++++
+ 5 files changed, 172 insertions(+)
+ create mode 100644 drivers/clocksource/cevt-rt3352.c
+
+diff --git a/arch/mips/ralink/Kconfig b/arch/mips/ralink/Kconfig
+index 8f49ed7..f5d97b8 100644
+--- a/arch/mips/ralink/Kconfig
++++ b/arch/mips/ralink/Kconfig
+@@ -15,6 +15,7 @@ choice
+ select USB_ARCH_HAS_HCD
+ select USB_ARCH_HAS_OHCI
+ select USB_ARCH_HAS_EHCI
++ select CLKEVT_RT3352
+
+ config SOC_RT3883
+ bool "RT3883"
+@@ -27,6 +28,7 @@ choice
+ select USB_ARCH_HAS_OHCI
+ select USB_ARCH_HAS_EHCI
+ select HW_HAS_PCI
++ select CLKEVT_RT3352
+
+ endchoice
+
+diff --git a/arch/mips/ralink/clk.c b/arch/mips/ralink/clk.c
+index 8dfa22f..bba0cdf 100644
+--- a/arch/mips/ralink/clk.c
++++ b/arch/mips/ralink/clk.c
+@@ -69,4 +69,5 @@ void __init plat_time_init(void)
+ pr_info("CPU Clock: %ldMHz\n", clk_get_rate(clk) / 1000000);
+ mips_hpt_frequency = clk_get_rate(clk) / 2;
+ clk_put(clk);
++ clocksource_of_init();
+ }
+diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
+index f151c6c..0e58a49 100644
+--- a/drivers/clocksource/Kconfig
++++ b/drivers/clocksource/Kconfig
+@@ -7,6 +7,12 @@ config CLKSRC_I8253
+ config CLKEVT_I8253
+ bool
+
++config CLKEVT_RT3352
++ bool
++ depends on MIPS && RALINK
++ select CLKSRC_OF
++ select CLKSRC_MMIO
++
+ config I8253_LOCK
+ bool
+
+diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
+index 8d979c7..423a2ef 100644
+--- a/drivers/clocksource/Makefile
++++ b/drivers/clocksource/Makefile
+@@ -10,6 +10,7 @@ obj-$(CONFIG_SH_TIMER_TMU) += sh_tmu.o
+ obj-$(CONFIG_EM_TIMER_STI) += em_sti.o
+ obj-$(CONFIG_CLKBLD_I8253) += i8253.o
+ obj-$(CONFIG_CLKSRC_MMIO) += mmio.o
++obj-$(CONFIG_CLKEVT_RT3352) += cevt-rt3352.o
+ obj-$(CONFIG_DW_APB_TIMER) += dw_apb_timer.o
+ obj-$(CONFIG_DW_APB_TIMER_OF) += dw_apb_timer_of.o
+ obj-$(CONFIG_CLKSRC_NOMADIK_MTU) += nomadik-mtu.o
+diff --git a/drivers/clocksource/cevt-rt3352.c b/drivers/clocksource/cevt-rt3352.c
+new file mode 100644
+index 0000000..bd50edd
+--- /dev/null
++++ b/drivers/clocksource/cevt-rt3352.c
+@@ -0,0 +1,162 @@
++/*
++ * This file is subject to the terms and conditions of the GNU General Public
++ * License. See the file "COPYING" in the main directory of this archive
++ * for more details.
++ *
++ * Copyright (C) 2013 by John Crispin <blogic@openwrt.org>
++ */
++
++#include <linux/clockchips.h>
++#include <linux/clocksource.h>
++#include <linux/interrupt.h>
++#include <linux/reset.h>
++#include <linux/init.h>
++#include <linux/of.h>
++#include <linux/of_irq.h>
++#include <linux/of_address.h>
++
++#include <asm/mach-ralink/ralink_regs.h>
++#include <asm/time.h>
++
++#define SYSTICK_FREQ (50 * 1000)
++
++#define SYSTICK_CONFIG 0x00
++#define SYSTICK_COMPARE 0x04
++#define SYSTICK_COUNT 0x08
++
++/* route systick irq to mips irq 7 instead of the r4k-timer */
++#define CFG_EXT_STK_EN 0x2
++/* enable the counter */
++#define CFG_CNT_EN 0x1
++
++struct systick_device {
++ void __iomem *membase;
++ struct clock_event_device dev;
++ int irq_requested;
++ int freq_scale;
++};
++
++static void systick_set_clock_mode(enum clock_event_mode mode,
++ struct clock_event_device *evt);
++
++static int systick_next_event(unsigned long delta,
++ struct clock_event_device *evt)
++{
++ struct systick_device *sdev = container_of(evt, struct systick_device, dev);
++ u32 count;
++
++ count = ioread32(sdev->membase + SYSTICK_COUNT);
++ count = (count + delta) % SYSTICK_FREQ;
++ iowrite32(count + delta, sdev->membase + SYSTICK_COMPARE);
++
++ return 0;
++}
++
++static void systick_event_handler(struct clock_event_device *dev)
++{
++ /* noting to do here */
++}
++
++static irqreturn_t systick_interrupt(int irq, void *dev_id)
++{
++ struct clock_event_device *dev = (struct clock_event_device *) dev_id;
++
++ dev->event_handler(dev);
++
++ return IRQ_HANDLED;
++}
++
++static struct systick_device systick = {
++ .dev = {
++ /* cevt-r4k uses 300, make sure systick gets used if available */
++ .rating = 310,
++ .features = CLOCK_EVT_FEAT_ONESHOT,
++ .set_next_event = systick_next_event,
++ .set_mode = systick_set_clock_mode,
++ .event_handler = systick_event_handler,
++ },
++};
++
++static struct irqaction systick_irqaction = {
++ .handler = systick_interrupt,
++ .flags = IRQF_PERCPU | IRQF_TIMER,
++ .dev_id = &systick.dev,
++};
++
++/* ugly hack */
++#ifdef CONFIG_SOC_MT7620
++
++#define CLK_LUT_CFG 0x40
++#define SLEEP_EN BIT(31)
++
++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);
++}
++#else
++static inline void mt7620_freq_scaling(struct systick_device *sdev, int status) {}
++#endif
++
++static void systick_set_clock_mode(enum clock_event_mode mode,
++ struct clock_event_device *evt)
++{
++ struct systick_device *sdev = container_of(evt, struct systick_device, dev);
++
++ switch (mode) {
++ case CLOCK_EVT_MODE_ONESHOT:
++ if (!sdev->irq_requested)
++ setup_irq(systick.dev.irq, &systick_irqaction);
++ mt7620_freq_scaling(sdev, 1);
++ sdev->irq_requested = 1;
++ iowrite32(CFG_EXT_STK_EN | CFG_CNT_EN, systick.membase + SYSTICK_CONFIG);
++ break;
++
++ case CLOCK_EVT_MODE_SHUTDOWN:
++ if (sdev->irq_requested)
++ free_irq(systick.dev.irq, &systick_irqaction);
++ mt7620_freq_scaling(sdev, 0);
++ sdev->irq_requested = 0;
++ iowrite32(0, systick.membase + SYSTICK_CONFIG);
++ break;
++
++ default:
++ pr_err("%s: Unhandeled mips clock_mode\n", systick.dev.name);
++ break;
++ }
++}
++
++static void __init ralink_systick_init(struct device_node *np)
++{
++ systick.membase = of_iomap(np, 0);
++ if (!systick.membase) {
++ pr_err("%s: of_iomap failed", np->name);
++ return;
++ }
++
++ clocksource_mmio_init(systick.membase + SYSTICK_COUNT, np->name,
++ SYSTICK_FREQ, 301, 16, clocksource_mmio_readl_up);
++
++ systick_irqaction.name = np->name;
++ systick.dev.name = np->name;
++ clockevent_set_clock(&systick.dev, SYSTICK_FREQ);
++ systick.dev.max_delta_ns = clockevent_delta2ns(0x7fff, &systick.dev);
++ systick.dev.min_delta_ns = clockevent_delta2ns(0x3, &systick.dev);
++ systick.dev.irq = irq_of_parse_and_map(np, 0);
++ if (!systick.dev.irq)
++ panic("%s: request_irq failed", np->name);
++
++ clockevents_register_device(&systick.dev);
++
++ pr_info("%s: runing - mult: %d, shift: %d\n", np->name, systick.dev.mult, systick.dev.shift);
++}
++
++CLOCKSOURCE_OF_DECLARE(systick, "ralink,cevt-systick", ralink_systick_init);
+--
+1.7.10.4
+
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