reset: add reset driver for HiSilicon platform
It adds a Driver Model compatible reset driver for HiSlicon platform.
The driver implements a custom .of_xlate function, and uses .data field
as reset register offset and .id field as bit shift.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
diff --git a/drivers/reset/reset-hisilicon.c b/drivers/reset/reset-hisilicon.c
new file mode 100644
index 0000000..a9f052a
--- /dev/null
+++ b/drivers/reset/reset-hisilicon.c
@@ -0,0 +1,103 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2019, Linaro Limited
+ */
+
+#include <asm/io.h>
+#include <common.h>
+#include <dm.h>
+#include <dt-bindings/reset/ti-syscon.h>
+#include <reset-uclass.h>
+
+struct hisi_reset_priv {
+ void __iomem *base;
+};
+
+static int hisi_reset_deassert(struct reset_ctl *rst)
+{
+ struct hisi_reset_priv *priv = dev_get_priv(rst->dev);
+ u32 val;
+
+ val = readl(priv->base + rst->data);
+ if (rst->polarity & DEASSERT_SET)
+ val |= BIT(rst->id);
+ else
+ val &= ~BIT(rst->id);
+ writel(val, priv->base + rst->data);
+
+ return 0;
+}
+
+static int hisi_reset_assert(struct reset_ctl *rst)
+{
+ struct hisi_reset_priv *priv = dev_get_priv(rst->dev);
+ u32 val;
+
+ val = readl(priv->base + rst->data);
+ if (rst->polarity & ASSERT_SET)
+ val |= BIT(rst->id);
+ else
+ val &= ~BIT(rst->id);
+ writel(val, priv->base + rst->data);
+
+ return 0;
+}
+
+static int hisi_reset_free(struct reset_ctl *rst)
+{
+ return 0;
+}
+
+static int hisi_reset_request(struct reset_ctl *rst)
+{
+ return 0;
+}
+
+static int hisi_reset_of_xlate(struct reset_ctl *rst,
+ struct ofnode_phandle_args *args)
+{
+ if (args->args_count != 3) {
+ debug("Invalid args_count: %d\n", args->args_count);
+ return -EINVAL;
+ }
+
+ /* Use .data field as register offset and .id field as bit shift */
+ rst->data = args->args[0];
+ rst->id = args->args[1];
+ rst->polarity = args->args[2];
+
+ return 0;
+}
+
+static const struct reset_ops hisi_reset_reset_ops = {
+ .of_xlate = hisi_reset_of_xlate,
+ .request = hisi_reset_request,
+ .free = hisi_reset_free,
+ .rst_assert = hisi_reset_assert,
+ .rst_deassert = hisi_reset_deassert,
+};
+
+static const struct udevice_id hisi_reset_ids[] = {
+ { .compatible = "hisilicon,hi3798cv200-reset" },
+ { }
+};
+
+static int hisi_reset_probe(struct udevice *dev)
+{
+ struct hisi_reset_priv *priv = dev_get_priv(dev);
+
+ priv->base = dev_remap_addr(dev);
+ if (!priv->base)
+ return -ENOMEM;
+
+ return 0;
+}
+
+U_BOOT_DRIVER(hisi_reset) = {
+ .name = "hisilicon_reset",
+ .id = UCLASS_RESET,
+ .of_match = hisi_reset_ids,
+ .ops = &hisi_reset_reset_ops,
+ .probe = hisi_reset_probe,
+ .priv_auto_alloc_size = sizeof(struct hisi_reset_priv),
+};