summaryrefslogtreecommitdiffstats
path: root/drivers/clocksource
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2012-12-13 10:57:16 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2012-12-13 10:57:16 -0800
commitb8edf848e9119bab9d999b9ca80d8520641810f2 (patch)
tree76517286b247626ed37dda41a4f946f6c34b8bff /drivers/clocksource
parentdb5b0ae00712b5176d7405e7a1dd2bfd6e8f5070 (diff)
parent3f54db784a6af9a6d53396949cbecf62edbad247 (diff)
downloadop-kernel-dev-b8edf848e9119bab9d999b9ca80d8520641810f2.zip
op-kernel-dev-b8edf848e9119bab9d999b9ca80d8520641810f2.tar.gz
Merge tag 'multiplatform' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull ARM SoC multiplatform conversion patches from Olof Johansson: "Here are more patches in the progression towards multiplatform, sparse irq conversions in particular. Tegra has a handful of cleanups and general groundwork, but is not quite there yet on full enablement. Platforms that are enabled through this branch are VT8500 and Zynq. Note that i.MX was converted in one of the earlier cleanup branches as well (before we started a separate topic for multiplatform). And both new platforms for this merge window, sunxi and bcm, were merged with multiplatform support enabled." Fix up conflicts mostly as per Olof. * tag 'multiplatform' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (29 commits) ARM: zynq: Remove all unused mach headers ARM: zynq: add support for ARCH_MULTIPLATFORM ARM: zynq: make use of debug_ll_io_init() ARM: zynq: remove TTC early mapping ARM: tegra: move debug-macro.S to include/debug ARM: tegra: don't include iomap.h from debug-macro.S ARM: tegra: decouple uncompress.h and debug-macro.S ARM: tegra: simplify DEBUG_LL UART selection options ARM: tegra: select SPARSE_IRQ ARM: tegra: enhance timer.c to get IO address from device tree ARM: tegra: enhance timer.c to get IRQ info from device tree ARM: timer: fix checkpatch warnings ARM: tegra: add TWD to device tree ARM: tegra: define DT bindings for and instantiate RTC ARM: tegra: define DT bindings for and instantiate timer clocksource/mtu-nomadik: use apb_pclk clk: ux500: Register mtu apb_pclocks ARM: plat-nomadik: convert platforms to SPARSE_IRQ mfd/db8500-prcmu: use the irq_domain_add_simple() mfd/ab8500-core: use irq_domain_add_simple() ...
Diffstat (limited to 'drivers/clocksource')
-rw-r--r--drivers/clocksource/Kconfig17
-rw-r--r--drivers/clocksource/Makefile1
-rw-r--r--drivers/clocksource/nomadik-mtu.c230
3 files changed, 247 insertions, 1 deletions
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index a098573..7fdcbd3 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -25,6 +25,21 @@ config ARMADA_370_XP_TIMER
config SUNXI_TIMER
bool
+config CLKSRC_NOMADIK_MTU
+ bool
+ depends on (ARCH_NOMADIK || ARCH_U8500)
+ select CLKSRC_MMIO
+ help
+ Support for Multi Timer Unit. MTU provides access
+ to multiple interrupt generating programmable
+ 32-bit free running decrementing counters.
+
+config CLKSRC_NOMADIK_MTU_SCHED_CLOCK
+ bool
+ depends on CLKSRC_NOMADIK_MTU
+ help
+ Use the Multi Timer Unit as the sched_clock.
+
config CLKSRC_DBX500_PRCMU
bool "Clocksource PRCMU Timer"
depends on UX500_SOC_DB8500
@@ -34,7 +49,7 @@ config CLKSRC_DBX500_PRCMU
config CLKSRC_DBX500_PRCMU_SCHED_CLOCK
bool "Clocksource PRCMU Timer sched_clock"
- depends on (CLKSRC_DBX500_PRCMU && !NOMADIK_MTU_SCHED_CLOCK)
+ depends on (CLKSRC_DBX500_PRCMU && !CLKSRC_NOMADIK_MTU_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 36f06de..f93453d 100644
--- a/drivers/clocksource/Makefile
+++ b/drivers/clocksource/Makefile
@@ -11,6 +11,7 @@ obj-$(CONFIG_CLKBLD_I8253) += i8253.o
obj-$(CONFIG_CLKSRC_MMIO) += mmio.o
obj-$(CONFIG_DW_APB_TIMER) += dw_apb_timer.o
obj-$(CONFIG_DW_APB_TIMER_OF) += dw_apb_timer_of.o
+obj-$(CONFIG_CLKSRC_NOMADIK_MTU) += nomadik-mtu.o
obj-$(CONFIG_CLKSRC_DBX500_PRCMU) += clksrc-dbx500-prcmu.o
obj-$(CONFIG_ARMADA_370_XP_TIMER) += time-armada-370-xp.o
obj-$(CONFIG_ARCH_BCM2835) += bcm2835_timer.o
diff --git a/drivers/clocksource/nomadik-mtu.c b/drivers/clocksource/nomadik-mtu.c
new file mode 100644
index 0000000..8914c3c
--- /dev/null
+++ b/drivers/clocksource/nomadik-mtu.c
@@ -0,0 +1,230 @@
+/*
+ * Copyright (C) 2008 STMicroelectronics
+ * Copyright (C) 2010 Alessandro Rubini
+ * Copyright (C) 2010 Linus Walleij for ST-Ericsson
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2, as
+ * published by the Free Software Foundation.
+ */
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/io.h>
+#include <linux/clockchips.h>
+#include <linux/clocksource.h>
+#include <linux/clk.h>
+#include <linux/jiffies.h>
+#include <linux/err.h>
+#include <linux/platform_data/clocksource-nomadik-mtu.h>
+#include <asm/mach/time.h>
+#include <asm/sched_clock.h>
+
+/*
+ * The MTU device hosts four different counters, with 4 set of
+ * registers. These are register names.
+ */
+
+#define MTU_IMSC 0x00 /* Interrupt mask set/clear */
+#define MTU_RIS 0x04 /* Raw interrupt status */
+#define MTU_MIS 0x08 /* Masked interrupt status */
+#define MTU_ICR 0x0C /* Interrupt clear register */
+
+/* per-timer registers take 0..3 as argument */
+#define MTU_LR(x) (0x10 + 0x10 * (x) + 0x00) /* Load value */
+#define MTU_VAL(x) (0x10 + 0x10 * (x) + 0x04) /* Current value */
+#define MTU_CR(x) (0x10 + 0x10 * (x) + 0x08) /* Control reg */
+#define MTU_BGLR(x) (0x10 + 0x10 * (x) + 0x0c) /* At next overflow */
+
+/* bits for the control register */
+#define MTU_CRn_ENA 0x80
+#define MTU_CRn_PERIODIC 0x40 /* if 0 = free-running */
+#define MTU_CRn_PRESCALE_MASK 0x0c
+#define MTU_CRn_PRESCALE_1 0x00
+#define MTU_CRn_PRESCALE_16 0x04
+#define MTU_CRn_PRESCALE_256 0x08
+#define MTU_CRn_32BITS 0x02
+#define MTU_CRn_ONESHOT 0x01 /* if 0 = wraps reloading from BGLR*/
+
+/* Other registers are usual amba/primecell registers, currently not used */
+#define MTU_ITCR 0xff0
+#define MTU_ITOP 0xff4
+
+#define MTU_PERIPH_ID0 0xfe0
+#define MTU_PERIPH_ID1 0xfe4
+#define MTU_PERIPH_ID2 0xfe8
+#define MTU_PERIPH_ID3 0xfeC
+
+#define MTU_PCELL0 0xff0
+#define MTU_PCELL1 0xff4
+#define MTU_PCELL2 0xff8
+#define MTU_PCELL3 0xffC
+
+static void __iomem *mtu_base;
+static bool clkevt_periodic;
+static u32 clk_prescale;
+static u32 nmdk_cycle; /* write-once */
+
+#ifdef CONFIG_NOMADIK_MTU_SCHED_CLOCK
+/*
+ * Override the global weak sched_clock symbol with this
+ * local implementation which uses the clocksource to get some
+ * better resolution when scheduling the kernel.
+ */
+static u32 notrace nomadik_read_sched_clock(void)
+{
+ if (unlikely(!mtu_base))
+ return 0;
+
+ return -readl(mtu_base + MTU_VAL(0));
+}
+#endif
+
+/* Clockevent device: use one-shot mode */
+static int nmdk_clkevt_next(unsigned long evt, struct clock_event_device *ev)
+{
+ writel(1 << 1, mtu_base + MTU_IMSC);
+ writel(evt, mtu_base + MTU_LR(1));
+ /* Load highest value, enable device, enable interrupts */
+ writel(MTU_CRn_ONESHOT | clk_prescale |
+ MTU_CRn_32BITS | MTU_CRn_ENA,
+ mtu_base + MTU_CR(1));
+
+ return 0;
+}
+
+void nmdk_clkevt_reset(void)
+{
+ if (clkevt_periodic) {
+ /* Timer: configure load and background-load, and fire it up */
+ writel(nmdk_cycle, mtu_base + MTU_LR(1));
+ writel(nmdk_cycle, mtu_base + MTU_BGLR(1));
+
+ writel(MTU_CRn_PERIODIC | clk_prescale |
+ MTU_CRn_32BITS | MTU_CRn_ENA,
+ mtu_base + MTU_CR(1));
+ writel(1 << 1, mtu_base + MTU_IMSC);
+ } else {
+ /* Generate an interrupt to start the clockevent again */
+ (void) nmdk_clkevt_next(nmdk_cycle, NULL);
+ }
+}
+
+static void nmdk_clkevt_mode(enum clock_event_mode mode,
+ struct clock_event_device *dev)
+{
+ switch (mode) {
+ case CLOCK_EVT_MODE_PERIODIC:
+ clkevt_periodic = true;
+ nmdk_clkevt_reset();
+ break;
+ case CLOCK_EVT_MODE_ONESHOT:
+ clkevt_periodic = false;
+ break;
+ case CLOCK_EVT_MODE_SHUTDOWN:
+ case CLOCK_EVT_MODE_UNUSED:
+ writel(0, mtu_base + MTU_IMSC);
+ /* disable timer */
+ writel(0, mtu_base + MTU_CR(1));
+ /* load some high default value */
+ writel(0xffffffff, mtu_base + MTU_LR(1));
+ break;
+ case CLOCK_EVT_MODE_RESUME:
+ break;
+ }
+}
+
+static struct clock_event_device nmdk_clkevt = {
+ .name = "mtu_1",
+ .features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERIODIC,
+ .rating = 200,
+ .set_mode = nmdk_clkevt_mode,
+ .set_next_event = nmdk_clkevt_next,
+};
+
+/*
+ * IRQ Handler for timer 1 of the MTU block.
+ */
+static irqreturn_t nmdk_timer_interrupt(int irq, void *dev_id)
+{
+ struct clock_event_device *evdev = dev_id;
+
+ writel(1 << 1, mtu_base + MTU_ICR); /* Interrupt clear reg */
+ evdev->event_handler(evdev);
+ return IRQ_HANDLED;
+}
+
+static struct irqaction nmdk_timer_irq = {
+ .name = "Nomadik Timer Tick",
+ .flags = IRQF_DISABLED | IRQF_TIMER,
+ .handler = nmdk_timer_interrupt,
+ .dev_id = &nmdk_clkevt,
+};
+
+void nmdk_clksrc_reset(void)
+{
+ /* Disable */
+ writel(0, mtu_base + MTU_CR(0));
+
+ /* ClockSource: configure load and background-load, and fire it up */
+ writel(nmdk_cycle, mtu_base + MTU_LR(0));
+ writel(nmdk_cycle, mtu_base + MTU_BGLR(0));
+
+ writel(clk_prescale | MTU_CRn_32BITS | MTU_CRn_ENA,
+ mtu_base + MTU_CR(0));
+}
+
+void __init nmdk_timer_init(void __iomem *base, int irq)
+{
+ unsigned long rate;
+ struct clk *clk0, *pclk0;
+
+ mtu_base = base;
+
+ pclk0 = clk_get_sys("mtu0", "apb_pclk");
+ BUG_ON(IS_ERR(pclk0));
+ BUG_ON(clk_prepare(pclk0) < 0);
+ BUG_ON(clk_enable(pclk0) < 0);
+
+ clk0 = clk_get_sys("mtu0", NULL);
+ BUG_ON(IS_ERR(clk0));
+ BUG_ON(clk_prepare(clk0) < 0);
+ BUG_ON(clk_enable(clk0) < 0);
+
+ /*
+ * Tick rate is 2.4MHz for Nomadik and 2.4Mhz, 100MHz or 133 MHz
+ * for ux500.
+ * Use a divide-by-16 counter if the tick rate is more than 32MHz.
+ * At 32 MHz, the timer (with 32 bit counter) can be programmed
+ * to wake-up at a max 127s a head in time. Dividing a 2.4 MHz timer
+ * with 16 gives too low timer resolution.
+ */
+ rate = clk_get_rate(clk0);
+ if (rate > 32000000) {
+ rate /= 16;
+ clk_prescale = MTU_CRn_PRESCALE_16;
+ } else {
+ clk_prescale = MTU_CRn_PRESCALE_1;
+ }
+
+ /* Cycles for periodic mode */
+ nmdk_cycle = DIV_ROUND_CLOSEST(rate, HZ);
+
+
+ /* Timer 0 is the free running clocksource */
+ nmdk_clksrc_reset();
+
+ if (clocksource_mmio_init(mtu_base + MTU_VAL(0), "mtu_0",
+ rate, 200, 32, clocksource_mmio_readl_down))
+ pr_err("timer: failed to initialize clock source %s\n",
+ "mtu_0");
+
+#ifdef CONFIG_NOMADIK_MTU_SCHED_CLOCK
+ setup_sched_clock(nomadik_read_sched_clock, 32, rate);
+#endif
+
+ /* Timer 1 is used for events, register irq and clockevents */
+ setup_irq(irq, &nmdk_timer_irq);
+ nmdk_clkevt.cpumask = cpumask_of(0);
+ clockevents_config_and_register(&nmdk_clkevt, rate, 2, 0xffffffffU);
+}
OpenPOWER on IntegriCloud