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authorChris Brand <chris.brand@broadcom.com>2016-05-11 14:36:17 -0700
committerFlorian Fainelli <f.fainelli@gmail.com>2016-06-06 16:17:33 -0700
commit783cb948d73b46aa336f0f0beb64789a0db35434 (patch)
tree8addfcd20fdaf1d08275c7184fd658a10197f955 /drivers/power/reset/brcm-kona-reset.c
parent34642650e5bc052674b982433631fcc619237225 (diff)
downloadlinux-stericsson-783cb948d73b46aa336f0f0beb64789a0db35434.tar.gz
power: Introduce Broadcom kona reset driver
This driver supports reset on both BCM21664 and BCM23550. Code is being moved from arch/arm/mach-bcm/board_bcm21664.c Signed-off-by: Chris Brand <chris.brand@broadcom.com> Acked-By: Sebastian Reichel <sre@kernel.org> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Diffstat (limited to 'drivers/power/reset/brcm-kona-reset.c')
-rw-r--r--drivers/power/reset/brcm-kona-reset.c73
1 files changed, 73 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 000000000000..8eaa959d8be6
--- /dev/null
+++ b/drivers/power/reset/brcm-kona-reset.c
@@ -0,0 +1,73 @@
+/*
+ * Copyright (C) 2016 Broadcom
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#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);