1 files changed, 66 insertions, 0 deletions
diff --git a/drivers/reset/starfive/reset-starfive-jh7100-audio.c b/drivers/reset/starfive/reset-starfive-jh7100-audio.c
new file mode 100644
index 000000000000..44ffef634fed
--- /dev/null
+++ b/drivers/reset/starfive/reset-starfive-jh7100-audio.c
@@ -0,0 +1,66 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Audio reset driver for the StarFive JH7100 SoC
+ *
+ * Copyright (C) 2021 Emil Renner Berthing <kernel@esmil.dk>
+ */
+
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+#include "reset-starfive-jh71x0.h"
+
+#include <dt-bindings/reset/starfive-jh7100-audio.h>
+
+/* register offsets */
+#define JH7100_AUDRST_ASSERT0	0x00
+#define JH7100_AUDRST_STATUS0	0x04
+
+/*
+ * Writing a 1 to the n'th bit of the ASSERT register asserts
+ * line 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_audrst_asserted[1] = {
+	BIT(JH7100_AUDRST_USB_AXI) |
+	BIT(JH7100_AUDRST_USB_PWRUP_RST_N) |
+	BIT(JH7100_AUDRST_USB_PONRST)
+};
+
+static int jh7100_audrst_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_AUDRST_ASSERT0,
+					      base + JH7100_AUDRST_STATUS0,
+					      jh7100_audrst_asserted,
+					      JH7100_AUDRSTN_END,
+					      THIS_MODULE);
+}
+
+static const struct of_device_id jh7100_audrst_dt_ids[] = {
+	{ .compatible = "starfive,jh7100-audrst" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, jh7100_audrst_dt_ids);
+
+static struct platform_driver jh7100_audrst_driver = {
+	.probe = jh7100_audrst_probe,
+	.driver = {
+		.name = "jh7100-reset-audio",
+		.of_match_table = jh7100_audrst_dt_ids,
+	},
+};
+module_platform_driver(jh7100_audrst_driver);
+
+MODULE_AUTHOR("Emil Renner Berthing");
+MODULE_DESCRIPTION("StarFive JH7100 audio reset driver");
+MODULE_LICENSE("GPL");