From b25913b40ee138c35d4c92e55898a365348d5769 Mon Sep 17 00:00:00 2001
From: Nick Hawkins <nick.hawkins@hpe.com>
Date: Wed, 8 Jun 2022 16:21:35 -0500
Subject: [PATCH] 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>
---
 drivers/timer/Kconfig     |  7 +++++
 drivers/timer/Makefile    |  1 +
 drivers/timer/gxp-timer.c | 64 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 72 insertions(+)
 create mode 100644 drivers/timer/gxp-timer.c

diff --git a/drivers/timer/Kconfig b/drivers/timer/Kconfig
index 7b8ab56ed3..d592dba285 100644
--- a/drivers/timer/Kconfig
+++ b/drivers/timer/Kconfig
@@ -139,6 +139,13 @@ config DESIGNWARE_APB_TIMER
 	  Enables support for the Designware APB Timer driver. This timer is
 	  present on Altera SoCFPGA SoCs.
 
+config GXP_TIMER
+	bool "HPE GXP Timer"
+	depends on TIMER
+	help
+	  Enables support for the GXP Timer driver. This timer is
+	  present on HPE GXP SoCs.
+
 config MPC83XX_TIMER
 	bool "MPC83xx timer support"
 	depends on TIMER
diff --git a/drivers/timer/Makefile b/drivers/timer/Makefile
index b2f002d597..cc2b8516b5 100644
--- a/drivers/timer/Makefile
+++ b/drivers/timer/Makefile
@@ -12,6 +12,7 @@ obj-$(CONFIG_$(SPL_)ATMEL_PIT_TIMER) += atmel_pit_timer.o
 obj-$(CONFIG_$(SPL_)ATMEL_TCB_TIMER) += atmel_tcb_timer.o
 obj-$(CONFIG_CADENCE_TTC_TIMER)	+= cadence-ttc.o
 obj-$(CONFIG_DESIGNWARE_APB_TIMER)	+= dw-apb-timer.o
+obj-$(CONFIG_GXP_TIMER)		+= gxp-timer.o
 obj-$(CONFIG_MPC83XX_TIMER) += mpc83xx_timer.o
 obj-$(CONFIG_NOMADIK_MTU_TIMER)	+= nomadik-mtu-timer.o
 obj-$(CONFIG_NPCM_TIMER)        += npcm-timer.o
diff --git a/drivers/timer/gxp-timer.c b/drivers/timer/gxp-timer.c
new file mode 100644
index 0000000000..6f316bc8c5
--- /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,
+};