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authorLinus Torvalds <torvalds@linux-foundation.org>2011-11-01 20:18:05 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2011-11-01 20:18:05 -0700
commitac5761a650d22dd7dfad4d417463a0981d2da0a4 (patch)
treec01a46a889dde74fbbb05d3b2da22387bb4875c6 /drivers/clocksource
parent25498e5b3df931a3d52a6e0642ae242e4ee19488 (diff)
parenteed1e576507b52e03e549e0c9e0c747978122403 (diff)
Merge branch 'next/timer' of git://git.linaro.org/people/arnd/arm-soc
* 'next/timer' of git://git.linaro.org/people/arnd/arm-soc: clocksource: fixup ux500 build problems ARM: omap: use __devexit_p in dmtimer driver ARM: ux500: Reprogram timers upon resume ARM: plat-nomadik: timer: Export reset functions ARM: plat-nomadik: timer: Add support for periodic timers ARM: ux500: Move timer code to separate file ARM: ux500: add support for clocksource DBX500 PRCMU clocksource: add DBX500 PRCMU Timer support ARM: plat-nomadik: MTU sched_clock as an option ARM: OMAP: dmtimer: add error handling to export APIs ARM: OMAP: dmtimer: low-power mode support ARM: OMAP: dmtimer: skip reserved timers ARM: OMAP: dmtimer: pm_runtime support ARM: OMAP: dmtimer: switch-over to platform device driver ARM: OMAP: dmtimer: platform driver ARM: OMAP2+: dmtimer: convert to platform devices ARM: OMAP1: dmtimer: conversion to platform devices ARM: OMAP2+: dmtimer: add device names to flck nodes ARM: OMAP: Add support for dmtimer v2 ip
Diffstat (limited to 'drivers/clocksource')
-rw-r--r--drivers/clocksource/Kconfig15
-rw-r--r--drivers/clocksource/Makefile1
-rw-r--r--drivers/clocksource/clksrc-dbx500-prcmu.c106
3 files changed, 122 insertions, 0 deletions
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index 34e9c4f88926..999d6a03e436 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -15,3 +15,18 @@ config CLKSRC_MMIO
config DW_APB_TIMER
bool
+
+config CLKSRC_DBX500_PRCMU
+ bool "Clocksource PRCMU Timer"
+ depends on UX500_SOC_DB5500 || UX500_SOC_DB8500
+ default y
+ help
+ Use the always on PRCMU Timer as clocksource
+
+config CLKSRC_DBX500_PRCMU_SCHED_CLOCK
+ bool "Clocksource PRCMU Timer sched_clock"
+ depends on (CLKSRC_DBX500_PRCMU && !NOMADIK_MTU_SCHED_CLOCK)
+ select HAVE_SCHED_CLOCK
+ default y
+ help
+ Use the always on PRCMU Timer as sched_clock
diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
index 85ad1646a7b7..8d81a1d32653 100644
--- a/drivers/clocksource/Makefile
+++ b/drivers/clocksource/Makefile
@@ -9,3 +9,4 @@ obj-$(CONFIG_SH_TIMER_TMU) += sh_tmu.o
obj-$(CONFIG_CLKBLD_I8253) += i8253.o
obj-$(CONFIG_CLKSRC_MMIO) += mmio.o
obj-$(CONFIG_DW_APB_TIMER) += dw_apb_timer.o
+obj-$(CONFIG_CLKSRC_DBX500_PRCMU) += clksrc-dbx500-prcmu.o \ No newline at end of file
diff --git a/drivers/clocksource/clksrc-dbx500-prcmu.c b/drivers/clocksource/clksrc-dbx500-prcmu.c
new file mode 100644
index 000000000000..59feefe0e3e6
--- /dev/null
+++ b/drivers/clocksource/clksrc-dbx500-prcmu.c
@@ -0,0 +1,106 @@
+/*
+ * Copyright (C) ST-Ericsson SA 2011
+ *
+ * License Terms: GNU General Public License v2
+ * Author: Mattias Wallin <mattias.wallin@stericsson.com> for ST-Ericsson
+ * Author: Sundar Iyer for ST-Ericsson
+ * sched_clock implementation is based on:
+ * plat-nomadik/timer.c Linus Walleij <linus.walleij@stericsson.com>
+ *
+ * DBx500-PRCMU Timer
+ * The PRCMU has 5 timers which are available in a always-on
+ * power domain. We use the Timer 4 for our always-on clock
+ * source on DB8500 and Timer 3 on DB5500.
+ */
+#include <linux/clockchips.h>
+#include <linux/clksrc-dbx500-prcmu.h>
+
+#include <asm/sched_clock.h>
+
+#include <mach/setup.h>
+#include <mach/hardware.h>
+
+#define RATE_32K 32768
+
+#define TIMER_MODE_CONTINOUS 0x1
+#define TIMER_DOWNCOUNT_VAL 0xffffffff
+
+#define PRCMU_TIMER_REF 0
+#define PRCMU_TIMER_DOWNCOUNT 0x4
+#define PRCMU_TIMER_MODE 0x8
+
+#define SCHED_CLOCK_MIN_WRAP 131072 /* 2^32 / 32768 */
+
+static void __iomem *clksrc_dbx500_timer_base;
+
+static cycle_t clksrc_dbx500_prcmu_read(struct clocksource *cs)
+{
+ u32 count, count2;
+
+ do {
+ count = readl(clksrc_dbx500_timer_base +
+ PRCMU_TIMER_DOWNCOUNT);
+ count2 = readl(clksrc_dbx500_timer_base +
+ PRCMU_TIMER_DOWNCOUNT);
+ } while (count2 != count);
+
+ /* Negate because the timer is a decrementing counter */
+ return ~count;
+}
+
+static struct clocksource clocksource_dbx500_prcmu = {
+ .name = "dbx500-prcmu-timer",
+ .rating = 300,
+ .read = clksrc_dbx500_prcmu_read,
+ .shift = 10,
+ .mask = CLOCKSOURCE_MASK(32),
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+#ifdef CONFIG_CLKSRC_DBX500_PRCMU_SCHED_CLOCK
+static DEFINE_CLOCK_DATA(cd);
+
+unsigned long long notrace sched_clock(void)
+{
+ u32 cyc;
+
+ if (unlikely(!clksrc_dbx500_timer_base))
+ return 0;
+
+ cyc = clksrc_dbx500_prcmu_read(&clocksource_dbx500_prcmu);
+
+ return cyc_to_sched_clock(&cd, cyc, (u32)~0);
+}
+
+static void notrace clksrc_dbx500_prcmu_update_sched_clock(void)
+{
+ u32 cyc = clksrc_dbx500_prcmu_read(&clocksource_dbx500_prcmu);
+ update_sched_clock(&cd, cyc, (u32)~0);
+}
+#endif
+
+void __init clksrc_dbx500_prcmu_init(void __iomem *base)
+{
+ clksrc_dbx500_timer_base = base;
+
+ /*
+ * The A9 sub system expects the timer to be configured as
+ * a continous looping timer.
+ * The PRCMU should configure it but if it for some reason
+ * don't we do it here.
+ */
+ if (readl(clksrc_dbx500_timer_base + PRCMU_TIMER_MODE) !=
+ TIMER_MODE_CONTINOUS) {
+ writel(TIMER_MODE_CONTINOUS,
+ clksrc_dbx500_timer_base + PRCMU_TIMER_MODE);
+ writel(TIMER_DOWNCOUNT_VAL,
+ clksrc_dbx500_timer_base + PRCMU_TIMER_REF);
+ }
+#ifdef CONFIG_CLKSRC_DBX500_PRCMU_SCHED_CLOCK
+ init_sched_clock(&cd, clksrc_dbx500_prcmu_update_sched_clock,
+ 32, RATE_32K);
+#endif
+ clocksource_calc_mult_shift(&clocksource_dbx500_prcmu,
+ RATE_32K, SCHED_CLOCK_MIN_WRAP);
+ clocksource_register(&clocksource_dbx500_prcmu);
+}