On 17/08/14 12:49, Carlo Caione wrote:
Meson6 SoCs are equipped with 5 32-bit timers, called TIMER_A, TIMER_B,
TIMER_C, TIMER_D and TIMER_E.
The driver is providing clocksource support for the 32-bit counter using
TIMER_E. Clockevents are also supported using TIMER_A.
Signed-off-by: Carlo Caione <ca...@caione.org>
---
drivers/clocksource/Kconfig | 3 +
drivers/clocksource/Makefile | 1 +
drivers/clocksource/meson6_timer.c | 187 +++++++++++++++++++++++++++++++++++++
3 files changed, 191 insertions(+)
create mode 100644 drivers/clocksource/meson6_timer.c
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index cfd6519..38029ca 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -30,6 +30,9 @@ config ARMADA_370_XP_TIMER
bool
select CLKSRC_OF
+config MESON6_TIMER
+ bool
+
config ORION_TIMER
select CLKSRC_OF
select CLKSRC_MMIO
diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
index 7fd9fd1..e4ae987 100644
--- a/drivers/clocksource/Makefile
+++ b/drivers/clocksource/Makefile
@@ -25,6 +25,7 @@ obj-$(CONFIG_ARCH_PRIMA2) += timer-prima2.o
obj-$(CONFIG_ARCH_U300) += timer-u300.o
obj-$(CONFIG_SUN4I_TIMER) += sun4i_timer.o
obj-$(CONFIG_SUN5I_HSTIMER) += timer-sun5i.o
+obj-$(CONFIG_MESON6_TIMER) += meson6_timer.o
obj-$(CONFIG_ARCH_TEGRA) += tegra20_timer.o
obj-$(CONFIG_VT8500_TIMER) += vt8500_timer.o
obj-$(CONFIG_ARCH_NSPIRE) += zevio-timer.o
diff --git a/drivers/clocksource/meson6_timer.c
b/drivers/clocksource/meson6_timer.c
new file mode 100644
index 0000000..1ef1095
--- /dev/null
+++ b/drivers/clocksource/meson6_timer.c
@@ -0,0 +1,187 @@
+/*
+ * Amlogic Meson6 SoCs timer handling.
+ *
+ * Copyright (C) 2014 Carlo Caione
+ *
+ * Carlo Caione <ca...@caione.org>
+ *
+ * Based on code from Amlogic, Inc
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/clk.h>
+#include <linux/clockchips.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/irqreturn.h>
+#include <linux/sched_clock.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+
+enum {
+ A = 0,
+ B,
+ C,
+ D,
+};
You are just using timer A, so this enum is unnecessary. Please use a
define instead. Also it would be better, if the define would be
explenatory then just the letter 'A'.
+
+#define TIMER_ISA_MUX 0
+#define TIMER_ISA_E_VAL 0x14
+#define TIMER_ISA_t_VAL(t) ((t + 1) << 2)
+
+#define TIMER_t_INPUT_BIT(t) (2 * t)
Please put braces around 't'.
+#define TIMER_E_INPUT_BIT 8
From the enum above, missing timer E would be 4 so you can use the
TIMER_t_INPUT_BIT(t) macro, right?
+#define TIMER_t_INPUT_MASK(t) (3UL << TIMER_t_INPUT_BIT(t))
+#define TIMER_E_INPUT_MASK (7UL << TIMER_E_INPUT_BIT)
+#define TIMER_t_ENABLE_BIT(t) (16 + t)
+#define TIMER_E_ENABLE_BIT 20
+#define TIMER_t_PERIODIC_BIT(t) (12 + t)
Please put braces around 't'.
+
+#define TIMER_UNIT_1us 0
+#define TIMER_E_UNIT_1us 1
Please don't use lower case characters in defines.
+
+static void __iomem *timer_base;
+
+static cycle_t cycle_read_timer_e(struct clocksource *cs)
+{
+ return (cycle_t)readl(timer_base + TIMER_ISA_E_VAL);
+}
+
+static struct clocksource clocksource_timer_e = {
+ .name = "meson6_timerE",
+ .rating = 300,
+ .read = cycle_read_timer_e,
+ .mask = CLOCKSOURCE_MASK(32),
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+static u64 notrace meson6_timer_sched_read(void)
+{
+ return (u64)readl(timer_base + TIMER_ISA_E_VAL);
+}
+
+static void meson6_clkevt_time_stop(unsigned char timer)
+{
+ u32 val = readl(timer_base + TIMER_ISA_MUX);
+
+ writel(val & ~TIMER_t_ENABLE_BIT(timer), timer_base + TIMER_ISA_MUX);
+}
+
+static void meson6_clkevt_time_setup(unsigned char timer, unsigned long delay)
+{
+ writel(delay, timer_base + TIMER_ISA_t_VAL(timer));
+}
+
+static void meson6_clkevt_time_start(unsigned char timer, bool periodic)
+{
+ u32 val = readl(timer_base + TIMER_ISA_MUX);
+
+ if (periodic)
+ val |= TIMER_t_PERIODIC_BIT(timer);
+ else
+ val &= ~TIMER_t_PERIODIC_BIT(timer);
+
+ writel(val | TIMER_t_ENABLE_BIT(timer), timer_base + TIMER_ISA_MUX);
+}
+
+static void meson6_clkevt_mode(enum clock_event_mode mode,
+ struct clock_event_device *clk)
+{
+ switch (mode) {
+ case CLOCK_EVT_MODE_PERIODIC:
+ meson6_clkevt_time_stop(A);
+ meson6_clkevt_time_setup(A, USEC_PER_SEC/HZ - 1);
+ meson6_clkevt_time_start(A, true);
+ break;
+ case CLOCK_EVT_MODE_ONESHOT:
+ meson6_clkevt_time_stop(A);
+ meson6_clkevt_time_start(A, false);
+ break;
+ case CLOCK_EVT_MODE_UNUSED:
+ case CLOCK_EVT_MODE_SHUTDOWN:
+ default:
+ meson6_clkevt_time_stop(A);
+ break;
+ }
+}
+
+static int meson6_clkevt_next_event(unsigned long evt,
+ struct clock_event_device *unused)
+{
+ meson6_clkevt_time_stop(A);
+ meson6_clkevt_time_setup(A, evt);
+ meson6_clkevt_time_start(A, false);
+
+ return 0;
+}
+
+static struct clock_event_device meson6_clockevent = {
+ .name = "meson6_tick",
+ .rating = 400,
+ .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
+ .set_mode = meson6_clkevt_mode,
+ .set_next_event = meson6_clkevt_next_event,
+};
+
+static irqreturn_t meson6_timer_interrupt(int irq, void *dev_id)
+{
+ struct clock_event_device *evt = (struct clock_event_device *)dev_id;
+
+ evt->event_handler(evt);
+
+ return IRQ_HANDLED;
+}
+
+static struct irqaction meson6_timer_irq = {
+ .name = "meson6_timerA",
+ .flags = IRQF_TIMER | IRQF_IRQPOLL,
+ .handler = meson6_timer_interrupt,
+ .dev_id = &meson6_clockevent,
+};
+
+static void __init meson6_timer_init(struct device_node *node)
+{
+ u32 val;
+ int ret, irq;
+
+ timer_base = of_iomap(node, 0);
Please use of_io_request_and_map instead.
+ if (!timer_base)
+ panic("Can't map registers");
+
+ irq = irq_of_parse_and_map(node, 0);
+ if (irq <= 0)
+ panic("Can't parse IRQ");
+
+ /* Set 1us for timer E */
+ val = readl(timer_base + TIMER_ISA_MUX);
+ val &= ~TIMER_E_INPUT_MASK;
+ val |= TIMER_E_UNIT_1us << TIMER_E_INPUT_BIT;
+ writel(val, timer_base + TIMER_ISA_MUX);
+
+ sched_clock_register(meson6_timer_sched_read, 32, USEC_PER_SEC);
+ clocksource_register_khz(&clocksource_timer_e, 1000);
Why don't you use clocksource_mmio_init?
+
+ /* Timer A base 1us */
+ val &= ~TIMER_t_INPUT_MASK(A);
+ val |= TIMER_UNIT_1us << TIMER_t_INPUT_BIT(A);
+ writel(val, timer_base + TIMER_ISA_MUX);
Is this dependant on any clocking of the timer?
+
+ /* Stop the timer A */
+ meson6_clkevt_time_stop(A);
+
+ ret = setup_irq(irq, &meson6_timer_irq);
+ if (ret)
+ pr_warn("failed to setup irq %d\n", irq);
+
+ meson6_clockevent.cpumask = cpu_possible_mask;
+ meson6_clockevent.irq = irq;
+
+ clockevents_config_and_register(&meson6_clockevent, USEC_PER_SEC,
+ 1, 0xfffe);
+}
+CLOCKSOURCE_OF_DECLARE(meson6, "amlogic,meson6-timer",
+ meson6_timer_init);
--
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