Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 202 insertions, 0 deletions

diff --git a/drivers/clocksource/bcm_kona_timer.c b/drivers/clocksource/bcm_kona_timer.c
new file mode 100644
index 000000000..a50ab5c21
--- /dev/null
+++ b/drivers/clocksource/bcm_kona_timer.c
@@ -0,0 +1,202 @@
+/*
+ * Copyright (C) 2012 Broadcom Corporation
+ *
+ * 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 version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/init.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/jiffies.h>
+#include <linux/clockchips.h>
+#include <linux/types.h>
+#include <linux/clk.h>
+
+#include <linux/io.h>
+
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+
+
+#define KONA_GPTIMER_STCS_OFFSET			0x00000000
+#define KONA_GPTIMER_STCLO_OFFSET			0x00000004
+#define KONA_GPTIMER_STCHI_OFFSET			0x00000008
+#define KONA_GPTIMER_STCM0_OFFSET			0x0000000C
+
+#define KONA_GPTIMER_STCS_TIMER_MATCH_SHIFT		0
+#define KONA_GPTIMER_STCS_COMPARE_ENABLE_SHIFT		4
+
+struct kona_bcm_timers {
+	int tmr_irq;
+	void __iomem *tmr_regs;
+};
+
+static struct kona_bcm_timers timers;
+
+static u32 arch_timer_rate;
+
+/*
+ * We use the peripheral timers for system tick, the cpu global timer for
+ * profile tick
+ */
+static void kona_timer_disable_and_clear(void __iomem *base)
+{
+	uint32_t reg;
+
+	/*
+	 * clear and disable interrupts
+	 * We are using compare/match register 0 for our system interrupts
+	 */
+	reg = readl(base + KONA_GPTIMER_STCS_OFFSET);
+
+	/* Clear compare (0) interrupt */
+	reg |= 1 << KONA_GPTIMER_STCS_TIMER_MATCH_SHIFT;
+	/* disable compare */
+	reg &= ~(1 << KONA_GPTIMER_STCS_COMPARE_ENABLE_SHIFT);
+
+	writel(reg, base + KONA_GPTIMER_STCS_OFFSET);
+
+}
+
+static int
+kona_timer_get_counter(void __iomem *timer_base, uint32_t *msw, uint32_t *lsw)
+{
+	int loop_limit = 3;
+
+	/*
+	 * Read 64-bit free running counter
+	 * 1. Read hi-word
+	 * 2. Read low-word
+	 * 3. Read hi-word again
+	 * 4.1
+	 *      if new hi-word is not equal to previously read hi-word, then
+	 *      start from #1
+	 * 4.2
+	 *      if new hi-word is equal to previously read hi-word then stop.
+	 */
+
+	do {
+		*msw = readl(timer_base + KONA_GPTIMER_STCHI_OFFSET);
+		*lsw = readl(timer_base + KONA_GPTIMER_STCLO_OFFSET);
+		if (*msw == readl(timer_base + KONA_GPTIMER_STCHI_OFFSET))
+			break;
+	} while (--loop_limit);
+	if (!loop_limit) {
+		pr_err("bcm_kona_timer: getting counter failed.\n");
+		pr_err(" Timer will be impacted\n");
+		return -ETIMEDOUT;
+	}
+
+	return 0;
+}
+
+static int kona_timer_set_next_event(unsigned long clc,
+				  struct clock_event_device *unused)
+{
+	/*
+	 * timer (0) is disabled by the timer interrupt already
+	 * so, here we reload the next event value and re-enable
+	 * the timer.
+	 *
+	 * This way, we are potentially losing the time between
+	 * timer-interrupt->set_next_event. CPU local timers, when
+	 * they come in should get rid of skew.
+	 */
+
+	uint32_t lsw, msw;
+	uint32_t reg;
+	int ret;
+
+	ret = kona_timer_get_counter(timers.tmr_regs, &msw, &lsw);
+	if (ret)
+		return ret;
+
+	/* Load the "next" event tick value */
+	writel(lsw + clc, timers.tmr_regs + KONA_GPTIMER_STCM0_OFFSET);
+
+	/* Enable compare */
+	reg = readl(timers.tmr_regs + KONA_GPTIMER_STCS_OFFSET);
+	reg |= (1 << KONA_GPTIMER_STCS_COMPARE_ENABLE_SHIFT);
+	writel(reg, timers.tmr_regs + KONA_GPTIMER_STCS_OFFSET);
+
+	return 0;
+}
+
+static int kona_timer_shutdown(struct clock_event_device *evt)
+{
+	kona_timer_disable_and_clear(timers.tmr_regs);
+	return 0;
+}
+
+static struct clock_event_device kona_clockevent_timer = {
+	.name = "timer 1",
+	.features = CLOCK_EVT_FEAT_ONESHOT,
+	.set_next_event = kona_timer_set_next_event,
+	.set_state_shutdown = kona_timer_shutdown,
+	.tick_resume = kona_timer_shutdown,
+};
+
+static void __init kona_timer_clockevents_init(void)
+{
+	kona_clockevent_timer.cpumask = cpumask_of(0);
+	clockevents_config_and_register(&kona_clockevent_timer,
+		arch_timer_rate, 6, 0xffffffff);
+}
+
+static irqreturn_t kona_timer_interrupt(int irq, void *dev_id)
+{
+	struct clock_event_device *evt = &kona_clockevent_timer;
+
+	kona_timer_disable_and_clear(timers.tmr_regs);
+	evt->event_handler(evt);
+	return IRQ_HANDLED;
+}
+
+static int __init kona_timer_init(struct device_node *node)
+{
+	u32 freq;
+	struct clk *external_clk;
+
+	external_clk = of_clk_get_by_name(node, NULL);
+
+	if (!IS_ERR(external_clk)) {
+		arch_timer_rate = clk_get_rate(external_clk);
+		clk_prepare_enable(external_clk);
+	} else if (!of_property_read_u32(node, "clock-frequency", &freq)) {
+		arch_timer_rate = freq;
+	} else {
+		pr_err("Kona Timer v1 unable to determine clock-frequency\n");
+		return -EINVAL;
+	}
+
+	/* Setup IRQ numbers */
+	timers.tmr_irq = irq_of_parse_and_map(node, 0);
+
+	/* Setup IO addresses */
+	timers.tmr_regs = of_iomap(node, 0);
+
+	kona_timer_disable_and_clear(timers.tmr_regs);
+
+	kona_timer_clockevents_init();
+	if (request_irq(timers.tmr_irq, kona_timer_interrupt, IRQF_TIMER,
+			"Kona Timer Tick", NULL))
+		pr_err("%s: request_irq() failed\n", "Kona Timer Tick");
+	kona_timer_set_next_event((arch_timer_rate / HZ), NULL);
+
+	return 0;
+}
+
+TIMER_OF_DECLARE(brcm_kona, "brcm,kona-timer", kona_timer_init);
+/*
+ * bcm,kona-timer is deprecated by brcm,kona-timer
+ * being kept here for driver compatibility
+ */
+TIMER_OF_DECLARE(bcm_kona, "bcm,kona-timer", kona_timer_init);