timer: gxp: Add HPE GXP timer support
Add support for the HPE GXP SOC timer. The GXP supports several different
kinds of timers but for the purpose of this driver there is only support
for the General Timer. The timer has a 1us resolution and is 56 bits.
Signed-off-by: Nick Hawkins <nick.hawkins@hpe.com>
diff --git a/drivers/timer/gxp-timer.c b/drivers/timer/gxp-timer.c
new file mode 100644
index 0000000..6f316bc
--- /dev/null
+++ b/drivers/timer/gxp-timer.c
@@ -0,0 +1,64 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * GXP timer driver
+ *
+ * (C) Copyright 2022 Hewlett Packard Enterprise Development LP.
+ * Author: Nick Hawkins <nick.hawkins@hpe.com>
+ * Author: Jean-Marie Verdun <verdun@hpe.com>
+ */
+
+#include <clk.h>
+#include <dm.h>
+#include <timer.h>
+#include <asm/io.h>
+
+#define USTIMELO 0x18
+#define USTIMEHI 0x1C
+
+struct gxp_timer_priv {
+ void __iomem *base;
+};
+
+static u64 gxp_timer_get_count(struct udevice *dev)
+{
+ struct gxp_timer_priv *priv = dev_get_priv(dev);
+ u64 val;
+
+ val = readl(priv->base + USTIMEHI);
+ val = (val << 32) | readl(priv->base + USTIMELO);
+
+ return val;
+}
+
+static int gxp_timer_probe(struct udevice *dev)
+{
+ struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev);
+ struct gxp_timer_priv *priv = dev_get_priv(dev);
+
+ priv->base = dev_read_addr_ptr(dev);
+ if (!priv->base)
+ return -ENOENT;
+
+ uc_priv->clock_rate = 1000000;
+
+ return 0;
+}
+
+static const struct timer_ops gxp_timer_ops = {
+ .get_count = gxp_timer_get_count,
+};
+
+static const struct udevice_id gxp_timer_ids[] = {
+ { .compatible = "hpe,gxp-timer" },
+ {}
+};
+
+U_BOOT_DRIVER(gxp_timer) = {
+ .name = "gxp-timer",
+ .id = UCLASS_TIMER,
+ .of_match = gxp_timer_ids,
+ .priv_auto = sizeof(struct gxp_timer_priv),
+ .probe = gxp_timer_probe,
+ .ops = &gxp_timer_ops,
+ .flags = DM_FLAG_PRE_RELOC,
+};