GK SDK 源码库: XMIPCLinuxV100R005C00SPC030 (kernel/tools/open_source excluded)

source/bootloader/u-boot-2020.01/drivers/timer/ast_timer.c

@@ -0,0 +1,93 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2016 Google Inc.
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <timer.h>
+#include <asm/io.h>
+#include <asm/arch/timer.h>
+
+#define AST_TICK_TIMER  1
+#define AST_TMC_RELOAD_VAL  0xffffffff
+
+struct ast_timer_priv {
+	struct ast_timer *regs;
+	struct ast_timer_counter *tmc;
+};
+
+static struct ast_timer_counter *ast_get_timer_counter(struct ast_timer *timer,
+						       int n)
+{
+	if (n > 3)
+		return &timer->timers2[n - 4];
+	else
+		return &timer->timers1[n - 1];
+}
+
+static int ast_timer_probe(struct udevice *dev)
+{
+	struct ast_timer_priv *priv = dev_get_priv(dev);
+	struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev);
+
+	writel(AST_TMC_RELOAD_VAL, &priv->tmc->reload_val);
+
+	/*
+	 * Stop the timer. This will also load reload_val into
+	 * the status register.
+	 */
+	clrbits_le32(&priv->regs->ctrl1,
+		     AST_TMC_EN << AST_TMC_CTRL1_SHIFT(AST_TICK_TIMER));
+	/* Start the timer from the fixed 1MHz clock. */
+	setbits_le32(&priv->regs->ctrl1,
+		     (AST_TMC_EN | AST_TMC_1MHZ) <<
+		     AST_TMC_CTRL1_SHIFT(AST_TICK_TIMER));
+
+	uc_priv->clock_rate = AST_TMC_RATE;
+
+	return 0;
+}
+
+static int ast_timer_get_count(struct udevice *dev, u64 *count)
+{
+	struct ast_timer_priv *priv = dev_get_priv(dev);
+
+	*count = AST_TMC_RELOAD_VAL - readl(&priv->tmc->status);
+
+	return 0;
+}
+
+static int ast_timer_ofdata_to_platdata(struct udevice *dev)
+{
+	struct ast_timer_priv *priv = dev_get_priv(dev);
+
+	priv->regs = devfdt_get_addr_ptr(dev);
+	if (IS_ERR(priv->regs))
+		return PTR_ERR(priv->regs);
+
+	priv->tmc = ast_get_timer_counter(priv->regs, AST_TICK_TIMER);
+
+	return 0;
+}
+
+static const struct timer_ops ast_timer_ops = {
+	.get_count = ast_timer_get_count,
+};
+
+static const struct udevice_id ast_timer_ids[] = {
+	{ .compatible = "aspeed,ast2500-timer" },
+	{ .compatible = "aspeed,ast2400-timer" },
+	{ }
+};
+
+U_BOOT_DRIVER(ast_timer) = {
+	.name = "ast_timer",
+	.id = UCLASS_TIMER,
+	.of_match = ast_timer_ids,
+	.probe = ast_timer_probe,
+	.priv_auto_alloc_size = sizeof(struct ast_timer_priv),
+	.ofdata_to_platdata = ast_timer_ofdata_to_platdata,
+	.ops = &ast_timer_ops,
+};