@@ -617,6 +617,14 @@ config CLKSRC_ST_LPC
Enable this option to use the Low Power controller timer
as clocksource.
+config GXP_TIMER
+ bool "GXP timer driver" if COMPILE_TEST && !ARCH_HPE
+ default ARCH_HPE
+ select TIMER_OF if OF
+ help
+ Provides a driver for the timer control found on HPE
+ GXP SOCs. This is required for all GXP SOCs.
+
config RISCV_TIMER
bool "Timer for the RISC-V platform" if COMPILE_TEST
depends on GENERIC_SCHED_CLOCK && RISCV && RISCV_SBI
@@ -88,3 +88,4 @@ obj-$(CONFIG_GX6605S_TIMER) += timer-gx6605s.o
obj-$(CONFIG_HYPERV_TIMER) += hyperv_timer.o
obj-$(CONFIG_MICROCHIP_PIT64B) += timer-microchip-pit64b.o
obj-$(CONFIG_MSC313E_TIMER) += timer-msc313e.o
+obj-$(CONFIG_GXP_TIMER) += timer-gxp.o
new file mode 100644
@@ -0,0 +1,209 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 2022 Hewlett-Packard Enterprise Development Company, L.P. */
+
+#include <linux/clk.h>
+#include <linux/clockchips.h>
+#include <linux/clocksource.h>
+#include <linux/interrupt.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.h>
+#include <linux/sched_clock.h>
+
+#define TIMER0_FREQ 1000000
+#define GXP_TIMER_CNT_OFS 0x00
+#define GXP_TIMESTAMP_OFS 0x08
+#define GXP_TIMER_CTRL_OFS 0x14
+
+/* TCS Stands for Timer Control/Status: these are masks to be used in */
+/* the Timer Count Registers */
+#define MASK_TCS_ENABLE 0x01
+#define MASK_TCS_PERIOD 0x02
+#define MASK_TCS_RELOAD 0x04
+#define MASK_TCS_TC 0x80
+
+struct gxp_timer {
+ void __iomem *counter;
+ void __iomem *control;
+ struct clock_event_device evt;
+};
+
+static struct gxp_timer *gxp_timer;
+
+static void __iomem *system_clock __ro_after_init;
+
+static inline struct gxp_timer *to_gxp_timer(struct clock_event_device *evt_dev)
+{
+ return container_of(evt_dev, struct gxp_timer, evt);
+}
+
+static u64 notrace gxp_sched_read(void)
+{
+ return readl_relaxed(system_clock);
+}
+
+static int gxp_time_set_next_event(unsigned long event, struct clock_event_device *evt_dev)
+{
+ struct gxp_timer *timer = to_gxp_timer(evt_dev);
+
+ /* Stop counting and disable interrupt before updating */
+ writeb_relaxed(MASK_TCS_TC, timer->control);
+ writel_relaxed(event, timer->counter);
+ writeb_relaxed(MASK_TCS_TC | MASK_TCS_ENABLE, timer->control);
+
+ return 0;
+}
+
+static irqreturn_t gxp_timer_interrupt(int irq, void *dev_id)
+{
+ struct gxp_timer *timer = (struct gxp_timer *)dev_id;
+
+ if (!(readb_relaxed(timer->control) & MASK_TCS_TC))
+ return IRQ_NONE;
+
+ writeb_relaxed(MASK_TCS_TC, timer->control);
+
+ timer->evt.event_handler(&timer->evt);
+
+ return IRQ_HANDLED;
+}
+
+static int __init gxp_timer_init(struct device_node *node)
+{
+ void __iomem *base;
+ struct clk *clk;
+ u32 freq;
+ int ret, irq;
+
+ gxp_timer = kzalloc(sizeof(*gxp_timer), GFP_KERNEL);
+ if (!gxp_timer) {
+ ret = -ENOMEM;
+ pr_err("Can't allocate gxp_timer");
+ return ret;
+ }
+
+ clk = of_clk_get(node, 0);
+ if (IS_ERR(clk)) {
+ ret = (int)PTR_ERR(clk);
+ pr_err("%pOFn clock not found: %d\n", node, ret);
+ goto err_free;
+ }
+
+ ret = clk_prepare_enable(clk);
+ if (ret) {
+ pr_err("%pOFn clock enable failed: %d\n", node, ret);
+ goto err_clk_enable;
+ }
+
+ base = of_iomap(node, 0);
+ if (!base) {
+ ret = -ENXIO;
+ pr_err("Can't map timer base registers");
+ goto err_iomap;
+ }
+
+ /* Set the offsets to the clock register and timer registers */
+ gxp_timer->counter = base + GXP_TIMER_CNT_OFS;
+ gxp_timer->control = base + GXP_TIMER_CTRL_OFS;
+ system_clock = base + GXP_TIMESTAMP_OFS;
+
+ gxp_timer->evt.name = node->name;
+ gxp_timer->evt.rating = 300;
+ gxp_timer->evt.features = CLOCK_EVT_FEAT_ONESHOT;
+ gxp_timer->evt.set_next_event = gxp_time_set_next_event;
+ gxp_timer->evt.cpumask = cpumask_of(0);
+
+ irq = irq_of_parse_and_map(node, 0);
+ if (irq <= 0) {
+ ret = -EINVAL;
+ pr_err("GXP Timer Can't parse IRQ %d", irq);
+ goto err_exit;
+ }
+
+ freq = clk_get_rate(clk);
+
+ ret = clocksource_mmio_init(system_clock, node->name, freq,
+ 300, 32, clocksource_mmio_readl_up);
+ if (ret) {
+ pr_err("%pOFn init clocksource failed: %d", node, ret);
+ goto err_exit;
+ }
+
+ sched_clock_register(gxp_sched_read, 32, freq);
+
+ irq = irq_of_parse_and_map(node, 0);
+ if (irq <= 0) {
+ ret = -EINVAL;
+ pr_err("%pOFn Can't parse IRQ %d", node, irq);
+ goto err_exit;
+ }
+
+ clockevents_config_and_register(&gxp_timer->evt, TIMER0_FREQ,
+ 0xf, 0xffffffff);
+
+ ret = request_irq(irq, gxp_timer_interrupt, IRQF_TIMER | IRQF_SHARED,
+ node->name, gxp_timer);
+ if (ret) {
+ pr_err("%pOFn request_irq() failed: %d", node, ret);
+ goto err_exit;
+ }
+
+ pr_debug("gxp: system timer (irq = %d)\n", irq);
+ return 0;
+
+err_exit:
+ iounmap(base);
+err_iomap:
+ clk_disable_unprepare(clk);
+err_clk_enable:
+ clk_put(clk);
+err_free:
+ kfree(gxp_timer);
+ return ret;
+}
+
+/*
+ * This probe gets called after the timer is already up and running. This will create
+ * the watchdog device as a child since the registers are shared.
+ */
+
+static int gxp_timer_probe(struct platform_device *pdev)
+{
+ struct platform_device *gxp_watchdog_device;
+ struct device *dev = &pdev->dev;
+
+ if (!gxp_timer) {
+ pr_err("Gxp Timer not initialized, cannot create watchdog");
+ return -ENOMEM;
+ }
+
+ gxp_watchdog_device = platform_device_alloc("gxp-wdt", -1);
+ if (!gxp_watchdog_device) {
+ pr_err("Timer failed to allocate gxp-wdt");
+ return -ENOMEM;
+ }
+
+ /* Pass the base address (counter) as platform data and nothing else */
+ gxp_watchdog_device->dev.platform_data = gxp_timer->counter;
+ gxp_watchdog_device->dev.parent = dev;
+
+ return platform_device_add(gxp_watchdog_device);
+}
+
+static const struct of_device_id gxp_timer_of_match[] = {
+ { .compatible = "hpe,gxp-timer", },
+ {},
+};
+
+static struct platform_driver gxp_timer_driver = {
+ .probe = gxp_timer_probe,
+ .driver = {
+ .name = "gxp-timer",
+ .of_match_table = gxp_timer_of_match,
+ .suppress_bind_attrs = true,
+ },
+};
+
+builtin_platform_driver(gxp_timer_driver);
+
+TIMER_OF_DECLARE(gxp, "hpe,gxp-timer", gxp_timer_init);