[PATCH] ARM: integrator: move AP timer to clocksource

From: Linus Walleij
Date: Thu Oct 16 2014 - 03:28:00 EST


This moves the timer/clocksource implementation for the
Integrator/AP down to drivers/clocksource and augments the
driver a little to use CLOCKSOURCE_OF_DECLARE(). Remove
the static mapping of the timer blocks while we're at it.

Tested on the Integrator/AP.

Cc: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
---
Daniel, Thomas: can you ACK this to be taken through ARM SoC?
---
arch/arm/mach-integrator/integrator_ap.c | 190 ---------------------------
drivers/clocksource/Makefile | 1 +
drivers/clocksource/timer-integrator-ap.c | 210 ++++++++++++++++++++++++++++++
3 files changed, 211 insertions(+), 190 deletions(-)
create mode 100644 drivers/clocksource/timer-integrator-ap.c

diff --git a/arch/arm/mach-integrator/integrator_ap.c b/arch/arm/mach-integrator/integrator_ap.c
index 8ca290b479b1..8a879b654fde 100644
--- a/arch/arm/mach-integrator/integrator_ap.c
+++ b/arch/arm/mach-integrator/integrator_ap.c
@@ -27,13 +27,9 @@
#include <linux/syscore_ops.h>
#include <linux/amba/bus.h>
#include <linux/amba/kmi.h>
-#include <linux/clocksource.h>
-#include <linux/clockchips.h>
-#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/irqchip.h>
#include <linux/mtd/physmap.h>
-#include <linux/clk.h>
#include <linux/platform_data/clk-integrator.h>
#include <linux/of_irq.h>
#include <linux/of_address.h>
@@ -41,8 +37,6 @@
#include <linux/stat.h>
#include <linux/sys_soc.h>
#include <linux/termios.h>
-#include <linux/sched_clock.h>
-#include <linux/clk-provider.h>

#include <asm/hardware/arm_timer.h>
#include <asm/setup.h>
@@ -89,11 +83,6 @@ static void __iomem *ebi_base;

static struct map_desc ap_io_desc[] __initdata __maybe_unused = {
{
- .virtual = IO_ADDRESS(INTEGRATOR_CT_BASE),
- .pfn = __phys_to_pfn(INTEGRATOR_CT_BASE),
- .length = SZ_4K,
- .type = MT_DEVICE
- }, {
.virtual = IO_ADDRESS(INTEGRATOR_IC_BASE),
.pfn = __phys_to_pfn(INTEGRATOR_IC_BASE),
.length = SZ_4K,
@@ -257,188 +246,10 @@ struct amba_pl010_data ap_uart_data = {
.set_mctrl = integrator_uart_set_mctrl,
};

-/*
- * Where is the timer (VA)?
- */
-#define TIMER0_VA_BASE __io_address(INTEGRATOR_TIMER0_BASE)
-#define TIMER1_VA_BASE __io_address(INTEGRATOR_TIMER1_BASE)
-#define TIMER2_VA_BASE __io_address(INTEGRATOR_TIMER2_BASE)
-
-static unsigned long timer_reload;
-
-static u64 notrace integrator_read_sched_clock(void)
-{
- return -readl((void __iomem *) TIMER2_VA_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_clock_register(integrator_read_sched_clock, 16, rate);
-}
-
-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);
-}
-
void __init ap_init_early(void)
{
}

-static void __init ap_of_timer_init(void)
-{
- struct device_node *node;
- const char *path;
- void __iomem *base;
- int err;
- int irq;
- struct clk *clk;
- unsigned long rate;
-
- of_clk_init(NULL);
-
- err = of_property_read_string(of_aliases,
- "arm,timer-primary", &path);
- if (WARN_ON(err))
- return;
- node = of_find_node_by_path(path);
- base = of_iomap(node, 0);
- if (WARN_ON(!base))
- return;
-
- clk = of_clk_get(node, 0);
- BUG_ON(IS_ERR(clk));
- clk_prepare_enable(clk);
- rate = clk_get_rate(clk);
-
- writel(0, base + TIMER_CTRL);
- integrator_clocksource_init(rate, base);
-
- err = of_property_read_string(of_aliases,
- "arm,timer-secondary", &path);
- if (WARN_ON(err))
- return;
- node = of_find_node_by_path(path);
- base = of_iomap(node, 0);
- if (WARN_ON(!base))
- return;
- irq = irq_of_parse_and_map(node, 0);
-
- clk = of_clk_get(node, 0);
- BUG_ON(IS_ERR(clk));
- clk_prepare_enable(clk);
- rate = clk_get_rate(clk);
-
- writel(0, base + TIMER_CTRL);
- integrator_clockevent_init(rate, base, irq);
-}
-
static void __init ap_init_irq_of(void)
{
cm_init();
@@ -553,7 +364,6 @@ DT_MACHINE_START(INTEGRATOR_AP_DT, "ARM Integrator/AP (Device Tree)")
.map_io = ap_map_io,
.init_early = ap_init_early,
.init_irq = ap_init_irq_of,
- .init_time = ap_of_timer_init,
.init_machine = ap_init_of,
.restart = integrator_restart,
.dt_compat = ap_dt_board_compat,
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);
--
1.9.3

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