1 files changed, 106 insertions, 0 deletions
diff --git a/drivers/reset/ast2500-reset.c b/drivers/reset/ast2500-reset.c
new file mode 100644
index 0000000..b2c89e1
--- /dev/null
+++ b/drivers/reset/ast2500-reset.c
@@ -0,0 +1,106 @@
+/*
+ * Copyright 2017 Google, Inc
+ *
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <misc.h>
+#include <reset.h>
+#include <reset-uclass.h>
+#include <wdt.h>
+#include <asm/io.h>
+#include <asm/arch/scu_ast2500.h>
+#include <asm/arch/wdt.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+struct ast2500_reset_priv {
+	/* WDT used to perform resets. */
+	struct udevice *wdt;
+	struct ast2500_scu *scu;
+};
+
+static int ast2500_ofdata_to_platdata(struct udevice *dev)
+{
+	struct ast2500_reset_priv *priv = dev_get_priv(dev);
+	int ret;
+
+	ret = uclass_get_device_by_phandle(UCLASS_WDT, dev, "aspeed,wdt",
+					   &priv->wdt);
+	if (ret) {
+		debug("%s: can't find WDT for reset controller", __func__);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int ast2500_reset_assert(struct reset_ctl *reset_ctl)
+{
+	struct ast2500_reset_priv *priv = dev_get_priv(reset_ctl->dev);
+	u32 reset_mode, reset_mask;
+	bool reset_sdram;
+	int ret;
+
+	/*
+	 * To reset SDRAM, a specifal flag in SYSRESET register
+	 * needs to be enabled first
+	 */
+	reset_mode = ast_reset_mode_from_flags(reset_ctl->id);
+	reset_mask = ast_reset_mask_from_flags(reset_ctl->id);
+	reset_sdram = reset_mode == WDT_CTRL_RESET_SOC &&
+		(reset_mask & WDT_RESET_SDRAM);
+
+	if (reset_sdram) {
+		ast_scu_unlock(priv->scu);
+		setbits_le32(&priv->scu->sysreset_ctrl1,
+			     SCU_SYSRESET_SDRAM_WDT);
+		ret = wdt_expire_now(priv->wdt, reset_ctl->id);
+		clrbits_le32(&priv->scu->sysreset_ctrl1,
+			     SCU_SYSRESET_SDRAM_WDT);
+		ast_scu_lock(priv->scu);
+	} else {
+		ret = wdt_expire_now(priv->wdt, reset_ctl->id);
+	}
+
+	return ret;
+}
+
+static int ast2500_reset_request(struct reset_ctl *reset_ctl)
+{
+	debug("%s(reset_ctl=%p) (dev=%p, id=%lu)\n", __func__, reset_ctl,
+	      reset_ctl->dev, reset_ctl->id);
+
+	return 0;
+}
+
+static int ast2500_reset_probe(struct udevice *dev)
+{
+	struct ast2500_reset_priv *priv = dev_get_priv(dev);
+
+	priv->scu = ast_get_scu();
+
+	return 0;
+}
+
+static const struct udevice_id ast2500_reset_ids[] = {
+	{ .compatible = "aspeed,ast2500-reset" },
+	{ }
+};
+
+struct reset_ops ast2500_reset_ops = {
+	.rst_assert = ast2500_reset_assert,
+	.request = ast2500_reset_request,
+};
+
+U_BOOT_DRIVER(ast2500_reset) = {
+	.name		= "ast2500_reset",
+	.id		= UCLASS_RESET,
+	.of_match = ast2500_reset_ids,
+	.probe = ast2500_reset_probe,
+	.ops = &ast2500_reset_ops,
+	.ofdata_to_platdata = ast2500_ofdata_to_platdata,
+	.priv_auto_alloc_size = sizeof(struct ast2500_reset_priv),
+};