STiH410: Add STi timer driver

Add ARM global timer based timer

Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

drivers/timer/Kconfig

@@ -58,4 +58,11 @@ config AST_TIMER
 	  This is mostly because they all share several registers which
 	  makes it difficult to completely separate them.
 
+config STI_TIMER
+	bool "STi timer support"
+	depends on TIMER
+	default y if ARCH_STI
+	help
+	  Select this to enable a timer for STi devices.
+
 endmenu

drivers/timer/Makefile

@@ -10,3 +10,4 @@ obj-$(CONFIG_SANDBOX_TIMER)	+= sandbox_timer.o
 obj-$(CONFIG_X86_TSC_TIMER)	+= tsc_timer.o
 obj-$(CONFIG_OMAP_TIMER)	+= omap-timer.o
 obj-$(CONFIG_AST_TIMER)	+= ast_timer.o
+obj-$(CONFIG_STI_TIMER)		+= sti-timer.o

drivers/timer/sti-timer.c

+/*
+ * (C) Copyright 2017 Patrice Chotard <patrice.chotard@st.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <fdtdec.h>
+#include <timer.h>
+
+#include <asm/io.h>
+#include <asm/arch-armv7/globaltimer.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+struct sti_timer_priv {
+	struct globaltimer *global_timer;
+};
+
+static int sti_timer_get_count(struct udevice *dev, u64 *count)
+{
+	struct sti_timer_priv *priv = dev_get_priv(dev);
+	struct globaltimer *global_timer = priv->global_timer;
+	u32 low, high;
+	u64 timer;
+	u32 old = readl(&global_timer->cnt_h);
+
+	while (1) {
+		low = readl(&global_timer->cnt_l);
+		high = readl(&global_timer->cnt_h);
+		if (old == high)
+			break;
+		else
+			old = high;
+	}
+	timer = high;
+	*count = (u64)((timer << 32) | low);
+
+	return 0;
+}
+
+static int sti_timer_probe(struct udevice *dev)
+{
+	struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev);
+	struct sti_timer_priv *priv = dev_get_priv(dev);
+	fdt_addr_t addr;
+
+	uc_priv->clock_rate = CONFIG_SYS_HZ_CLOCK;
+
+	/* get arm global timer base address */
+	addr = fdtdec_get_addr(gd->fdt_blob, dev_of_offset(dev), "reg");
+	priv->global_timer = (struct globaltimer *)addr;
+
+	/* init timer */
+	writel(0x01, &priv->global_timer->ctl);
+
+	return 0;
+}
+
+static const struct timer_ops sti_timer_ops = {
+	.get_count = sti_timer_get_count,
+};
+
+static const struct udevice_id sti_timer_ids[] = {
+	{ .compatible = "arm,cortex-a9-global-timer" },
+	{}
+};
+
+U_BOOT_DRIVER(sti_timer) = {
+	.name = "sti_timer",
+	.id = UCLASS_TIMER,
+	.of_match = sti_timer_ids,
+	.priv_auto_alloc_size = sizeof(struct sti_timer_priv),
+	.probe = sti_timer_probe,
+	.ops = &sti_timer_ops,
+	.flags = DM_FLAG_PRE_RELOC,
+};