1 files changed, 74 insertions, 0 deletions
diff --git a/drivers/reset/starfive/reset-starfive-jh7100.c b/drivers/reset/starfive/reset-starfive-jh7100.c
new file mode 100644
index 000000000..2a56f7fd4
--- /dev/null
+++ b/drivers/reset/starfive/reset-starfive-jh7100.c
@@ -0,0 +1,74 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Reset driver for the StarFive JH7100 SoC
+ *
+ * Copyright (C) 2021 Emil Renner Berthing <kernel@esmil.dk>
+ */
+
+#include <linux/mod_devicetable.h>
+#include <linux/platform_device.h>
+
+#include "reset-starfive-jh71x0.h"
+
+#include <dt-bindings/reset/starfive-jh7100.h>
+
+/* register offsets */
+#define JH7100_RESET_ASSERT0	0x00
+#define JH7100_RESET_ASSERT1	0x04
+#define JH7100_RESET_ASSERT2	0x08
+#define JH7100_RESET_ASSERT3	0x0c
+#define JH7100_RESET_STATUS0	0x10
+#define JH7100_RESET_STATUS1	0x14
+#define JH7100_RESET_STATUS2	0x18
+#define JH7100_RESET_STATUS3	0x1c
+
+/*
+ * Writing a 1 to the n'th bit of the m'th ASSERT register asserts
+ * line 32m + n, and writing a 0 deasserts the same line.
+ * Most reset lines have their status inverted so a 0 bit in the STATUS
+ * register means the line is asserted and a 1 means it's deasserted. A few
+ * lines don't though, so store the expected value of the status registers when
+ * all lines are asserted.
+ */
+static const u32 jh7100_reset_asserted[4] = {
+	/* STATUS0 */
+	BIT(JH7100_RST_U74 % 32) |
+	BIT(JH7100_RST_VP6_DRESET % 32) |
+	BIT(JH7100_RST_VP6_BRESET % 32),
+	/* STATUS1 */
+	BIT(JH7100_RST_HIFI4_DRESET % 32) |
+	BIT(JH7100_RST_HIFI4_BRESET % 32),
+	/* STATUS2 */
+	BIT(JH7100_RST_E24 % 32),
+	/* STATUS3 */
+	0,
+};
+
+static int __init jh7100_reset_probe(struct platform_device *pdev)
+{
+	void __iomem *base = devm_platform_ioremap_resource(pdev, 0);
+
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	return reset_starfive_jh71x0_register(&pdev->dev, pdev->dev.of_node,
+					      base + JH7100_RESET_ASSERT0,
+					      base + JH7100_RESET_STATUS0,
+					      jh7100_reset_asserted,
+					      JH7100_RSTN_END,
+					      THIS_MODULE);
+}
+
+static const struct of_device_id jh7100_reset_dt_ids[] = {
+	{ .compatible = "starfive,jh7100-reset" },
+	{ /* sentinel */ }
+};
+
+static struct platform_driver jh7100_reset_driver = {
+	.driver = {
+		.name = "jh7100-reset",
+		.of_match_table = jh7100_reset_dt_ids,
+		.suppress_bind_attrs = true,
+	},
+};
+builtin_platform_driver_probe(jh7100_reset_driver, jh7100_reset_probe);