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path: root/drivers/power/reset/brcm-kona-reset.c
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Diffstat (limited to 'drivers/power/reset/brcm-kona-reset.c')
-rw-r--r--drivers/power/reset/brcm-kona-reset.c61
1 files changed, 61 insertions, 0 deletions
diff --git a/drivers/power/reset/brcm-kona-reset.c b/drivers/power/reset/brcm-kona-reset.c
new file mode 100644
index 0000000000..d05728b1db
--- /dev/null
+++ b/drivers/power/reset/brcm-kona-reset.c
@@ -0,0 +1,61 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (C) 2016 Broadcom
+
+#include <linux/io.h>
+#include <linux/mod_devicetable.h>
+#include <linux/platform_device.h>
+#include <linux/reboot.h>
+
+#define RSTMGR_REG_WR_ACCESS_OFFSET 0
+#define RSTMGR_REG_CHIP_SOFT_RST_OFFSET 4
+
+#define RSTMGR_WR_PASSWORD 0xa5a5
+#define RSTMGR_WR_PASSWORD_SHIFT 8
+#define RSTMGR_WR_ACCESS_ENABLE 1
+
+static void __iomem *kona_reset_base;
+
+static int kona_reset_handler(struct notifier_block *this,
+ unsigned long mode, void *cmd)
+{
+ /*
+ * A soft reset is triggered by writing a 0 to bit 0 of the soft reset
+ * register. To write to that register we must first write the password
+ * and the enable bit in the write access enable register.
+ */
+ writel((RSTMGR_WR_PASSWORD << RSTMGR_WR_PASSWORD_SHIFT) |
+ RSTMGR_WR_ACCESS_ENABLE,
+ kona_reset_base + RSTMGR_REG_WR_ACCESS_OFFSET);
+ writel(0, kona_reset_base + RSTMGR_REG_CHIP_SOFT_RST_OFFSET);
+
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block kona_reset_nb = {
+ .notifier_call = kona_reset_handler,
+ .priority = 128,
+};
+
+static int kona_reset_probe(struct platform_device *pdev)
+{
+ kona_reset_base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(kona_reset_base))
+ return PTR_ERR(kona_reset_base);
+
+ return register_restart_handler(&kona_reset_nb);
+}
+
+static const struct of_device_id of_match[] = {
+ { .compatible = "brcm,bcm21664-resetmgr" },
+ {},
+};
+
+static struct platform_driver bcm_kona_reset_driver = {
+ .probe = kona_reset_probe,
+ .driver = {
+ .name = "brcm-kona-reset",
+ .of_match_table = of_match,
+ },
+};
+
+builtin_platform_driver(bcm_kona_reset_driver);