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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /arch/microblaze/kernel/timer.c
Initial import
Diffstat (limited to 'arch/microblaze/kernel/timer.c')
-rw-r--r--arch/microblaze/kernel/timer.c319
1 files changed, 319 insertions, 0 deletions
diff --git a/arch/microblaze/kernel/timer.c b/arch/microblaze/kernel/timer.c
new file mode 100644
index 000000000..c8977450e
--- /dev/null
+++ b/arch/microblaze/kernel/timer.c
@@ -0,0 +1,319 @@
+/*
+ * Copyright (C) 2007-2013 Michal Simek <monstr@monstr.eu>
+ * Copyright (C) 2012-2013 Xilinx, Inc.
+ * Copyright (C) 2007-2009 PetaLogix
+ * Copyright (C) 2006 Atmark Techno, Inc.
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/sched.h>
+#include <linux/sched_clock.h>
+#include <linux/clk.h>
+#include <linux/clockchips.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/timecounter.h>
+#include <asm/cpuinfo.h>
+
+static void __iomem *timer_baseaddr;
+
+static unsigned int freq_div_hz;
+static unsigned int timer_clock_freq;
+
+#define TCSR0 (0x00)
+#define TLR0 (0x04)
+#define TCR0 (0x08)
+#define TCSR1 (0x10)
+#define TLR1 (0x14)
+#define TCR1 (0x18)
+
+#define TCSR_MDT (1<<0)
+#define TCSR_UDT (1<<1)
+#define TCSR_GENT (1<<2)
+#define TCSR_CAPT (1<<3)
+#define TCSR_ARHT (1<<4)
+#define TCSR_LOAD (1<<5)
+#define TCSR_ENIT (1<<6)
+#define TCSR_ENT (1<<7)
+#define TCSR_TINT (1<<8)
+#define TCSR_PWMA (1<<9)
+#define TCSR_ENALL (1<<10)
+
+static unsigned int (*read_fn)(void __iomem *);
+static void (*write_fn)(u32, void __iomem *);
+
+static void timer_write32(u32 val, void __iomem *addr)
+{
+ iowrite32(val, addr);
+}
+
+static unsigned int timer_read32(void __iomem *addr)
+{
+ return ioread32(addr);
+}
+
+static void timer_write32_be(u32 val, void __iomem *addr)
+{
+ iowrite32be(val, addr);
+}
+
+static unsigned int timer_read32_be(void __iomem *addr)
+{
+ return ioread32be(addr);
+}
+
+static inline void xilinx_timer0_stop(void)
+{
+ write_fn(read_fn(timer_baseaddr + TCSR0) & ~TCSR_ENT,
+ timer_baseaddr + TCSR0);
+}
+
+static inline void xilinx_timer0_start_periodic(unsigned long load_val)
+{
+ if (!load_val)
+ load_val = 1;
+ /* loading value to timer reg */
+ write_fn(load_val, timer_baseaddr + TLR0);
+
+ /* load the initial value */
+ write_fn(TCSR_LOAD, timer_baseaddr + TCSR0);
+
+ /* see timer data sheet for detail
+ * !ENALL - don't enable 'em all
+ * !PWMA - disable pwm
+ * TINT - clear interrupt status
+ * ENT- enable timer itself
+ * ENIT - enable interrupt
+ * !LOAD - clear the bit to let go
+ * ARHT - auto reload
+ * !CAPT - no external trigger
+ * !GENT - no external signal
+ * UDT - set the timer as down counter
+ * !MDT0 - generate mode
+ */
+ write_fn(TCSR_TINT|TCSR_ENIT|TCSR_ENT|TCSR_ARHT|TCSR_UDT,
+ timer_baseaddr + TCSR0);
+}
+
+static inline void xilinx_timer0_start_oneshot(unsigned long load_val)
+{
+ if (!load_val)
+ load_val = 1;
+ /* loading value to timer reg */
+ write_fn(load_val, timer_baseaddr + TLR0);
+
+ /* load the initial value */
+ write_fn(TCSR_LOAD, timer_baseaddr + TCSR0);
+
+ write_fn(TCSR_TINT|TCSR_ENIT|TCSR_ENT|TCSR_ARHT|TCSR_UDT,
+ timer_baseaddr + TCSR0);
+}
+
+static int xilinx_timer_set_next_event(unsigned long delta,
+ struct clock_event_device *dev)
+{
+ pr_debug("%s: next event, delta %x\n", __func__, (u32)delta);
+ xilinx_timer0_start_oneshot(delta);
+ return 0;
+}
+
+static void xilinx_timer_set_mode(enum clock_event_mode mode,
+ struct clock_event_device *evt)
+{
+ switch (mode) {
+ case CLOCK_EVT_MODE_PERIODIC:
+ pr_info("%s: periodic\n", __func__);
+ xilinx_timer0_start_periodic(freq_div_hz);
+ break;
+ case CLOCK_EVT_MODE_ONESHOT:
+ pr_info("%s: oneshot\n", __func__);
+ break;
+ case CLOCK_EVT_MODE_UNUSED:
+ pr_info("%s: unused\n", __func__);
+ break;
+ case CLOCK_EVT_MODE_SHUTDOWN:
+ pr_info("%s: shutdown\n", __func__);
+ xilinx_timer0_stop();
+ break;
+ case CLOCK_EVT_MODE_RESUME:
+ pr_info("%s: resume\n", __func__);
+ break;
+ }
+}
+
+static struct clock_event_device clockevent_xilinx_timer = {
+ .name = "xilinx_clockevent",
+ .features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERIODIC,
+ .shift = 8,
+ .rating = 300,
+ .set_next_event = xilinx_timer_set_next_event,
+ .set_mode = xilinx_timer_set_mode,
+};
+
+static inline void timer_ack(void)
+{
+ write_fn(read_fn(timer_baseaddr + TCSR0), timer_baseaddr + TCSR0);
+}
+
+static irqreturn_t timer_interrupt(int irq, void *dev_id)
+{
+ struct clock_event_device *evt = &clockevent_xilinx_timer;
+#ifdef CONFIG_HEART_BEAT
+ microblaze_heartbeat();
+#endif
+ timer_ack();
+ evt->event_handler(evt);
+ return IRQ_HANDLED;
+}
+
+static struct irqaction timer_irqaction = {
+ .handler = timer_interrupt,
+ .flags = IRQF_TIMER,
+ .name = "timer",
+ .dev_id = &clockevent_xilinx_timer,
+};
+
+static __init void xilinx_clockevent_init(void)
+{
+ clockevent_xilinx_timer.mult =
+ div_sc(timer_clock_freq, NSEC_PER_SEC,
+ clockevent_xilinx_timer.shift);
+ clockevent_xilinx_timer.max_delta_ns =
+ clockevent_delta2ns((u32)~0, &clockevent_xilinx_timer);
+ clockevent_xilinx_timer.min_delta_ns =
+ clockevent_delta2ns(1, &clockevent_xilinx_timer);
+ clockevent_xilinx_timer.cpumask = cpumask_of(0);
+ clockevents_register_device(&clockevent_xilinx_timer);
+}
+
+static u64 xilinx_clock_read(void)
+{
+ return read_fn(timer_baseaddr + TCR1);
+}
+
+static cycle_t xilinx_read(struct clocksource *cs)
+{
+ /* reading actual value of timer 1 */
+ return (cycle_t)xilinx_clock_read();
+}
+
+static struct timecounter xilinx_tc = {
+ .cc = NULL,
+};
+
+static cycle_t xilinx_cc_read(const struct cyclecounter *cc)
+{
+ return xilinx_read(NULL);
+}
+
+static struct cyclecounter xilinx_cc = {
+ .read = xilinx_cc_read,
+ .mask = CLOCKSOURCE_MASK(32),
+ .shift = 8,
+};
+
+static int __init init_xilinx_timecounter(void)
+{
+ xilinx_cc.mult = div_sc(timer_clock_freq, NSEC_PER_SEC,
+ xilinx_cc.shift);
+
+ timecounter_init(&xilinx_tc, &xilinx_cc, sched_clock());
+
+ return 0;
+}
+
+static struct clocksource clocksource_microblaze = {
+ .name = "xilinx_clocksource",
+ .rating = 300,
+ .read = xilinx_read,
+ .mask = CLOCKSOURCE_MASK(32),
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+static int __init xilinx_clocksource_init(void)
+{
+ if (clocksource_register_hz(&clocksource_microblaze, timer_clock_freq))
+ panic("failed to register clocksource");
+
+ /* stop timer1 */
+ write_fn(read_fn(timer_baseaddr + TCSR1) & ~TCSR_ENT,
+ timer_baseaddr + TCSR1);
+ /* start timer1 - up counting without interrupt */
+ write_fn(TCSR_TINT|TCSR_ENT|TCSR_ARHT, timer_baseaddr + TCSR1);
+
+ /* register timecounter - for ftrace support */
+ init_xilinx_timecounter();
+ return 0;
+}
+
+static void __init xilinx_timer_init(struct device_node *timer)
+{
+ struct clk *clk;
+ static int initialized;
+ u32 irq;
+ u32 timer_num = 1;
+
+ if (initialized)
+ return;
+
+ initialized = 1;
+
+ timer_baseaddr = of_iomap(timer, 0);
+ if (!timer_baseaddr) {
+ pr_err("ERROR: invalid timer base address\n");
+ BUG();
+ }
+
+ write_fn = timer_write32;
+ read_fn = timer_read32;
+
+ write_fn(TCSR_MDT, timer_baseaddr + TCSR0);
+ if (!(read_fn(timer_baseaddr + TCSR0) & TCSR_MDT)) {
+ write_fn = timer_write32_be;
+ read_fn = timer_read32_be;
+ }
+
+ irq = irq_of_parse_and_map(timer, 0);
+
+ of_property_read_u32(timer, "xlnx,one-timer-only", &timer_num);
+ if (timer_num) {
+ pr_emerg("Please enable two timers in HW\n");
+ BUG();
+ }
+
+ pr_info("%s: irq=%d\n", timer->full_name, irq);
+
+ clk = of_clk_get(timer, 0);
+ if (IS_ERR(clk)) {
+ pr_err("ERROR: timer CCF input clock not found\n");
+ /* If there is clock-frequency property than use it */
+ of_property_read_u32(timer, "clock-frequency",
+ &timer_clock_freq);
+ } else {
+ timer_clock_freq = clk_get_rate(clk);
+ }
+
+ if (!timer_clock_freq) {
+ pr_err("ERROR: Using CPU clock frequency\n");
+ timer_clock_freq = cpuinfo.cpu_clock_freq;
+ }
+
+ freq_div_hz = timer_clock_freq / HZ;
+
+ setup_irq(irq, &timer_irqaction);
+#ifdef CONFIG_HEART_BEAT
+ microblaze_setup_heartbeat();
+#endif
+ xilinx_clocksource_init();
+ xilinx_clockevent_init();
+
+ sched_clock_register(xilinx_clock_read, 32, timer_clock_freq);
+}
+
+CLOCKSOURCE_OF_DECLARE(xilinx_timer, "xlnx,xps-timer-1.00.a",
+ xilinx_timer_init);