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Diffstat (limited to '')
-rw-r--r-- | drivers/power/reset/brcm-kona-reset.c | 63 |
1 files changed, 63 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 000000000..3de024e3c --- /dev/null +++ b/drivers/power/reset/brcm-kona-reset.c @@ -0,0 +1,63 @@ +// SPDX-License-Identifier: GPL-2.0-only +// Copyright (C) 2016 Broadcom + +#include <linux/io.h> +#include <linux/of_address.h> +#include <linux/of_platform.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) +{ + struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + + kona_reset_base = devm_ioremap_resource(&pdev->dev, res); + 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); |