1 files changed, 108 insertions, 0 deletions
diff --git a/drivers/timer/sp804_timer.c b/drivers/timer/sp804_timer.c
new file mode 100644
index 0000000000..8fd4afb15a
--- /dev/null
+++ b/drivers/timer/sp804_timer.c
@@ -0,0 +1,108 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * ARM PrimeCell Dual-Timer Module (SP804) driver
+ * Copyright (C) 2022 Arm Ltd.
+ */
+
+#include <common.h>
+#include <clk.h>
+#include <dm.h>
+#include <init.h>
+#include <log.h>
+#include <asm/global_data.h>
+#include <dm/ofnode.h>
+#include <mapmem.h>
+#include <dt-structs.h>
+#include <timer.h>
+#include <asm/io.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+#define SP804_TIMERX_LOAD		0x00
+#define SP804_TIMERX_VALUE		0x04
+#define SP804_TIMERX_CONTROL		0x08
+
+#define SP804_CTRL_TIMER_ENABLE		(1U << 7)
+#define SP804_CTRL_TIMER_PERIODIC	(1U << 6)
+#define SP804_CTRL_INT_ENABLE		(1U << 5)
+#define SP804_CTRL_TIMER_PRESCALE_SHIFT	2
+#define SP804_CTRL_TIMER_PRESCALE_MASK	(3U << SP804_CTRL_TIMER_PRESCALE_SHIFT)
+#define SP804_CTRL_TIMER_32BIT		(1U << 1)
+#define SP804_CTRL_ONESHOT		(1U << 0)
+
+
+struct sp804_timer_plat {
+	uintptr_t base;
+};
+
+static u64 sp804_timer_get_count(struct udevice *dev)
+{
+	struct sp804_timer_plat *plat = dev_get_plat(dev);
+	uint32_t cntr = readl(plat->base + SP804_TIMERX_VALUE);
+
+	/* timers are down-counting */
+	return ~0u - cntr;
+}
+
+static int sp804_clk_of_to_plat(struct udevice *dev)
+{
+	struct sp804_timer_plat *plat = dev_get_plat(dev);
+
+	plat->base = dev_read_addr(dev);
+	if (!plat->base)
+		return -ENOENT;
+
+	return 0;
+}
+
+static int sp804_timer_probe(struct udevice *dev)
+{
+	struct sp804_timer_plat *plat = dev_get_plat(dev);
+	struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev);
+	struct clk base_clk;
+	unsigned int divider = 1;
+	uint32_t ctlr;
+	int ret;
+
+	ctlr = readl(plat->base + SP804_TIMERX_CONTROL);
+	ctlr &= SP804_CTRL_TIMER_PRESCALE_MASK;
+	switch (ctlr >> SP804_CTRL_TIMER_PRESCALE_SHIFT) {
+	case 0x0: divider = 1; break;
+	case 0x1: divider = 16; break;
+	case 0x2: divider = 256; break;
+	case 0x3: printf("illegal!\n"); break;
+	}
+
+	ret = clk_get_by_index(dev, 0, &base_clk);
+	if (ret) {
+		printf("could not find SP804 timer base clock in DT\n");
+		return ret;
+	}
+
+	uc_priv->clock_rate = clk_get_rate(&base_clk) / divider;
+
+	/* keep divider, free-running, wrapping, no IRQs, 32-bit mode */
+	ctlr |= SP804_CTRL_TIMER_32BIT | SP804_CTRL_TIMER_ENABLE;
+	writel(ctlr, plat->base + SP804_TIMERX_CONTROL);
+
+	return 0;
+}
+
+static const struct timer_ops sp804_timer_ops = {
+	.get_count = sp804_timer_get_count,
+};
+
+static const struct udevice_id sp804_timer_ids[] = {
+	{ .compatible = "arm,sp804" },
+	{}
+};
+
+U_BOOT_DRIVER(arm_sp804_timer) = {
+	.name		= "arm_sp804_timer",
+	.id		= UCLASS_TIMER,
+	.of_match 	= sp804_timer_ids,
+	.probe		= sp804_timer_probe,
+	.ops		= &sp804_timer_ops,
+	.plat_auto	= sizeof(struct sp804_timer_plat),
+	.of_to_plat 	= sp804_clk_of_to_plat,
+};