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author | Arnd Bergmann <arnd@arndb.de> | 2014-11-20 17:13:55 +0100 |
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committer | Arnd Bergmann <arnd@arndb.de> | 2014-11-20 17:13:55 +0100 |
commit | 4eca459bc10d8400407d0fc04e90dac45b571c87 (patch) | |
tree | 02dac5128653db41bc732c3649402b99d70d4c41 /drivers/clocksource | |
parent | d686ce4204c5dc131396f1fca81beebc46cb8cdb (diff) | |
parent | f956a785a282f6b5a3e7d59937548f8b7c04d1ac (diff) | |
download | linux-4eca459bc10d8400407d0fc04e90dac45b571c87.tar.gz linux-4eca459bc10d8400407d0fc04e90dac45b571c87.tar.xz |
Merge tag 'integrator-v3.19-arm-soc-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-integrator into next/soc
Pull "ARM SoC Integrator updates for v3.19" from Linus Walleij:
Integrator updates for the v3.19 merge cycle on
top of the multiplatform patches, this moves out
some drivers and reduced the amount of code carried
in arch/arm/mach-integrator.
- Move the Integrator/AP timer to drivers/clocksource
- Move the restart functionality to the device tree,
patches to enable restart for the Integrator have
been merged to the reset tree (orthogonal)
- Move debug LEDs to device tree (using the syscon
LED driver merged for v3.18)
- Move core module LEDs to device tree (using the
syscon LED driver merged for v3.18)
- Move the SoC driver (chip ID etc) to
drivers/soc/versatile/soc-integrator.c
* tag 'integrator-v3.19-arm-soc-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-integrator:
soc: move SoC driver for the ARM Integrator
ARM: integrator: move core module LED to device tree
ARM: integrator: move debug LEDs to syscon LED driver
ARM: integrator: move restart to the device tree
ARM: integrator: move AP timer to clocksource
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'drivers/clocksource')
-rw-r--r-- | drivers/clocksource/Makefile | 1 | ||||
-rw-r--r-- | drivers/clocksource/timer-integrator-ap.c | 210 |
2 files changed, 211 insertions, 0 deletions
diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile index 756f6f10efa0..fae0435cc23d 100644 --- a/drivers/clocksource/Makefile +++ b/drivers/clocksource/Makefile @@ -45,4 +45,5 @@ obj-$(CONFIG_ARM_GLOBAL_TIMER) += arm_global_timer.o obj-$(CONFIG_CLKSRC_METAG_GENERIC) += metag_generic.o obj-$(CONFIG_ARCH_HAS_TICK_BROADCAST) += dummy_timer.o obj-$(CONFIG_ARCH_KEYSTONE) += timer-keystone.o +obj-$(CONFIG_ARCH_INTEGRATOR_AP) += timer-integrator-ap.o obj-$(CONFIG_CLKSRC_VERSATILE) += versatile.o diff --git a/drivers/clocksource/timer-integrator-ap.c b/drivers/clocksource/timer-integrator-ap.c new file mode 100644 index 000000000000..b9efd30513d5 --- /dev/null +++ b/drivers/clocksource/timer-integrator-ap.c @@ -0,0 +1,210 @@ +/* + * Integrator/AP timer driver + * Copyright (C) 2000-2003 Deep Blue Solutions Ltd + * Copyright (c) 2014, Linaro Limited + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include <linux/clk.h> +#include <linux/clocksource.h> +#include <linux/of_irq.h> +#include <linux/of_address.h> +#include <linux/of_platform.h> +#include <linux/clockchips.h> +#include <linux/interrupt.h> +#include <linux/sched_clock.h> +#include <asm/hardware/arm_timer.h> + +static void __iomem * sched_clk_base; + +static u64 notrace integrator_read_sched_clock(void) +{ + return -readl(sched_clk_base + TIMER_VALUE); +} + +static void integrator_clocksource_init(unsigned long inrate, + void __iomem *base) +{ + u32 ctrl = TIMER_CTRL_ENABLE | TIMER_CTRL_PERIODIC; + unsigned long rate = inrate; + + if (rate >= 1500000) { + rate /= 16; + ctrl |= TIMER_CTRL_DIV16; + } + + writel(0xffff, base + TIMER_LOAD); + writel(ctrl, base + TIMER_CTRL); + + clocksource_mmio_init(base + TIMER_VALUE, "timer2", + rate, 200, 16, clocksource_mmio_readl_down); + + sched_clk_base = base; + sched_clock_register(integrator_read_sched_clock, 16, rate); +} + +static unsigned long timer_reload; +static void __iomem * clkevt_base; + +/* + * IRQ handler for the timer + */ +static irqreturn_t integrator_timer_interrupt(int irq, void *dev_id) +{ + struct clock_event_device *evt = dev_id; + + /* clear the interrupt */ + writel(1, clkevt_base + TIMER_INTCLR); + + evt->event_handler(evt); + + return IRQ_HANDLED; +} + +static void clkevt_set_mode(enum clock_event_mode mode, struct clock_event_device *evt) +{ + u32 ctrl = readl(clkevt_base + TIMER_CTRL) & ~TIMER_CTRL_ENABLE; + + /* Disable timer */ + writel(ctrl, clkevt_base + TIMER_CTRL); + + switch (mode) { + case CLOCK_EVT_MODE_PERIODIC: + /* Enable the timer and start the periodic tick */ + writel(timer_reload, clkevt_base + TIMER_LOAD); + ctrl |= TIMER_CTRL_PERIODIC | TIMER_CTRL_ENABLE; + writel(ctrl, clkevt_base + TIMER_CTRL); + break; + case CLOCK_EVT_MODE_ONESHOT: + /* Leave the timer disabled, .set_next_event will enable it */ + ctrl &= ~TIMER_CTRL_PERIODIC; + writel(ctrl, clkevt_base + TIMER_CTRL); + break; + case CLOCK_EVT_MODE_UNUSED: + case CLOCK_EVT_MODE_SHUTDOWN: + case CLOCK_EVT_MODE_RESUME: + default: + /* Just leave in disabled state */ + break; + } + +} + +static int clkevt_set_next_event(unsigned long next, struct clock_event_device *evt) +{ + unsigned long ctrl = readl(clkevt_base + TIMER_CTRL); + + writel(ctrl & ~TIMER_CTRL_ENABLE, clkevt_base + TIMER_CTRL); + writel(next, clkevt_base + TIMER_LOAD); + writel(ctrl | TIMER_CTRL_ENABLE, clkevt_base + TIMER_CTRL); + + return 0; +} + +static struct clock_event_device integrator_clockevent = { + .name = "timer1", + .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT, + .set_mode = clkevt_set_mode, + .set_next_event = clkevt_set_next_event, + .rating = 300, +}; + +static struct irqaction integrator_timer_irq = { + .name = "timer", + .flags = IRQF_TIMER | IRQF_IRQPOLL, + .handler = integrator_timer_interrupt, + .dev_id = &integrator_clockevent, +}; + +static void integrator_clockevent_init(unsigned long inrate, + void __iomem *base, int irq) +{ + unsigned long rate = inrate; + unsigned int ctrl = 0; + + clkevt_base = base; + /* Calculate and program a divisor */ + if (rate > 0x100000 * HZ) { + rate /= 256; + ctrl |= TIMER_CTRL_DIV256; + } else if (rate > 0x10000 * HZ) { + rate /= 16; + ctrl |= TIMER_CTRL_DIV16; + } + timer_reload = rate / HZ; + writel(ctrl, clkevt_base + TIMER_CTRL); + + setup_irq(irq, &integrator_timer_irq); + clockevents_config_and_register(&integrator_clockevent, + rate, + 1, + 0xffffU); +} + +static void __init integrator_ap_timer_init_of(struct device_node *node) +{ + const char *path; + void __iomem *base; + int err; + int irq; + struct clk *clk; + unsigned long rate; + struct device_node *pri_node; + struct device_node *sec_node; + + base = of_io_request_and_map(node, 0, "integrator-timer"); + if (!base) + return; + + clk = of_clk_get(node, 0); + if (IS_ERR(clk)) { + pr_err("No clock for %s\n", node->name); + return; + } + clk_prepare_enable(clk); + rate = clk_get_rate(clk); + writel(0, base + TIMER_CTRL); + + err = of_property_read_string(of_aliases, + "arm,timer-primary", &path); + if (WARN_ON(err)) + return; + pri_node = of_find_node_by_path(path); + err = of_property_read_string(of_aliases, + "arm,timer-secondary", &path); + if (WARN_ON(err)) + return; + sec_node = of_find_node_by_path(path); + + if (node == pri_node) { + /* The primary timer lacks IRQ, use as clocksource */ + integrator_clocksource_init(rate, base); + return; + } + + if (node == sec_node) { + /* The secondary timer will drive the clock event */ + irq = irq_of_parse_and_map(node, 0); + integrator_clockevent_init(rate, base, irq); + return; + } + + pr_info("Timer @%p unused\n", base); + clk_disable_unprepare(clk); +} + +CLOCKSOURCE_OF_DECLARE(integrator_ap_timer, "arm,integrator-timer", + integrator_ap_timer_init_of); |