From: Alexandre Belloni <alexandre.belloni@free-electrons.com>
To: James Hogan <jhogan@kernel.org>, Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org, linux-kernel@vger.kernel.org,
Alexandre Belloni <alexandre.belloni@free-electrons.com>,
Sebastian Reichel <sre@kernel.org>,
linux-pm@vger.kernel.org
Subject: [PATCH v3 3/8] power: reset: Add a driver for the Microsemi Ocelot reset
Date: Tue, 16 Jan 2018 11:12:35 +0100 [thread overview]
Message-ID: <20180116101240.5393-4-alexandre.belloni@free-electrons.com> (raw)
In-Reply-To: <20180116101240.5393-1-alexandre.belloni@free-electrons.com>
The Microsemi Ocelot SoC has a register allowing to reset the MIPS core.
Unfortunately, the syscon-reboot driver can't be used directly (but almost)
as the reset control may be disabled using another register.
Cc: Sebastian Reichel <sre@kernel.org>
Cc: linux-pm@vger.kernel.org
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
---
drivers/power/reset/Kconfig | 7 +++
drivers/power/reset/Makefile | 1 +
drivers/power/reset/ocelot-reset.c | 88 ++++++++++++++++++++++++++++++++++++++
3 files changed, 96 insertions(+)
create mode 100644 drivers/power/reset/ocelot-reset.c
diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig
index ca0de1a78e85..2372f8e1040d 100644
--- a/drivers/power/reset/Kconfig
+++ b/drivers/power/reset/Kconfig
@@ -113,6 +113,13 @@ config POWER_RESET_MSM
help
Power off and restart support for Qualcomm boards.
+config POWER_RESET_OCELOT_RESET
+ bool "Microsemi Ocelot reset driver"
+ depends on MSCC_OCELOT || COMPILE_TEST
+ select MFD_SYSCON
+ help
+ This driver supports restart for Microsemi Ocelot SoC.
+
config POWER_RESET_PIIX4_POWEROFF
tristate "Intel PIIX4 power-off driver"
depends on PCI
diff --git a/drivers/power/reset/Makefile b/drivers/power/reset/Makefile
index aeb65edb17b7..df9d92291c67 100644
--- a/drivers/power/reset/Makefile
+++ b/drivers/power/reset/Makefile
@@ -12,6 +12,7 @@ obj-$(CONFIG_POWER_RESET_GPIO_RESTART) += gpio-restart.o
obj-$(CONFIG_POWER_RESET_HISI) += hisi-reboot.o
obj-$(CONFIG_POWER_RESET_IMX) += imx-snvs-poweroff.o
obj-$(CONFIG_POWER_RESET_MSM) += msm-poweroff.o
+obj-$(CONFIG_POWER_RESET_OCELOT_RESET) += ocelot-reset.o
obj-$(CONFIG_POWER_RESET_PIIX4_POWEROFF) += piix4-poweroff.o
obj-$(CONFIG_POWER_RESET_LTC2952) += ltc2952-poweroff.o
obj-$(CONFIG_POWER_RESET_QNAP) += qnap-poweroff.o
diff --git a/drivers/power/reset/ocelot-reset.c b/drivers/power/reset/ocelot-reset.c
new file mode 100644
index 000000000000..5a13a5cc8188
--- /dev/null
+++ b/drivers/power/reset/ocelot-reset.c
@@ -0,0 +1,88 @@
+// SPDX-License-Identifier: (GPL-2.0 OR MIT)
+/*
+ * Microsemi MIPS SoC reset driver
+ *
+ * License: Dual MIT/GPL
+ * Copyright (c) 2017 Microsemi Corporation
+ */
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/notifier.h>
+#include <linux/mfd/syscon.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/reboot.h>
+#include <linux/regmap.h>
+
+struct ocelot_reset_context {
+ void __iomem *base;
+ struct regmap *cpu_ctrl;
+ struct notifier_block restart_handler;
+};
+
+#define ICPU_CFG_CPU_SYSTEM_CTRL_RESET 0x20
+#define CORE_RST_PROTECT BIT(2)
+
+#define SOFT_CHIP_RST BIT(0)
+
+static int ocelot_restart_handle(struct notifier_block *this,
+ unsigned long mode, void *cmd)
+{
+ struct ocelot_reset_context *ctx = container_of(this, struct
+ ocelot_reset_context,
+ restart_handler);
+
+ /* Make sure the core is not protected from reset */
+ regmap_update_bits(ctx->cpu_ctrl, ICPU_CFG_CPU_SYSTEM_CTRL_RESET,
+ CORE_RST_PROTECT, 0);
+
+ writel(SOFT_CHIP_RST, ctx->base);
+
+ pr_emerg("Unable to restart system\n");
+ return NOTIFY_DONE;
+}
+
+static int ocelot_reset_probe(struct platform_device *pdev)
+{
+ struct ocelot_reset_context *ctx;
+ struct resource *res;
+
+ struct device *dev = &pdev->dev;
+ int err;
+
+ ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL);
+ if (!ctx)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ ctx->base = devm_ioremap_resource(dev, res);
+ if (IS_ERR(ctx->base))
+ return PTR_ERR(ctx->base);
+
+ ctx->cpu_ctrl = syscon_regmap_lookup_by_compatible("mscc,ocelot-cpu-syscon");
+ if (IS_ERR(ctx->cpu_ctrl))
+ return PTR_ERR(ctx->cpu_ctrl);
+
+ ctx->restart_handler.notifier_call = ocelot_restart_handle;
+ ctx->restart_handler.priority = 192;
+ err = register_restart_handler(&ctx->restart_handler);
+ if (err)
+ dev_err(dev, "can't register restart notifier (err=%d)\n", err);
+
+ return err;
+}
+
+static const struct of_device_id ocelot_reset_of_match[] = {
+ { .compatible = "mscc,ocelot-chip-reset" },
+ {}
+};
+
+static struct platform_driver ocelot_reset_driver = {
+ .probe = ocelot_reset_probe,
+ .driver = {
+ .name = "ocelot-chip-reset",
+ .of_match_table = ocelot_reset_of_match,
+ },
+};
+builtin_platform_driver(ocelot_reset_driver);
--
2.15.1
next prev parent reply other threads:[~2018-01-16 10:14 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-16 10:12 [PATCH v3 0/8] MIPS: add support for the Microsemi MIPS SoCs Alexandre Belloni
2018-01-16 10:12 ` [PATCH v3 1/8] dt-bindings: mips: Add bindings for Microsemi SoCs Alexandre Belloni
2018-01-19 19:23 ` Rob Herring
2018-02-14 16:38 ` James Hogan
2018-01-16 10:12 ` [PATCH v3 2/8] dt-bindings: power: reset: Document ocelot-reset binding Alexandre Belloni
2018-01-20 0:34 ` Rob Herring
2018-02-08 22:32 ` Sebastian Reichel
2018-01-16 10:12 ` Alexandre Belloni [this message]
2018-02-08 22:32 ` [PATCH v3 3/8] power: reset: Add a driver for the Microsemi Ocelot reset Sebastian Reichel
2018-01-16 10:12 ` [PATCH v3 4/8] MIPS: mscc: Add initial support for Microsemi MIPS SoCs Alexandre Belloni
2018-02-14 16:51 ` James Hogan
2018-02-14 21:38 ` Philippe Ombredanne
2018-01-16 10:12 ` [PATCH v3 5/8] MIPS: mscc: add ocelot dtsi Alexandre Belloni
2018-02-14 16:57 ` James Hogan
2018-02-27 15:47 ` Alexandre Belloni
2018-02-27 21:01 ` Jonas Gorski
2018-02-28 13:14 ` Alexandre Belloni
2018-01-16 10:12 ` [PATCH v3 6/8] MIPS: mscc: add ocelot PCB123 device tree Alexandre Belloni
2018-02-14 17:00 ` James Hogan
2018-02-27 15:54 ` Alexandre Belloni
2018-02-27 15:57 ` James Hogan
2018-01-16 10:12 ` [PATCH v3 7/8] MIPS: defconfigs: add a defconfig for Microsemi SoCs Alexandre Belloni
2018-02-14 17:03 ` James Hogan
2018-02-27 16:15 ` Alexandre Belloni
2018-02-27 16:23 ` James Hogan
2018-01-16 10:12 ` [PATCH v3 8/8] MAINTAINERS: Add entry for Microsemi MIPS SoCs Alexandre Belloni
2018-02-14 17:05 ` James Hogan
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