From: Maxime Coquelin <mcoquelin.stm32@gmail.com>
To: u.kleine-koenig@pengutronix.de, afaerber@suse.de,
geert@linux-m68k.org, Rob Herring <robh+dt@kernel.org>,
Philipp Zabel <p.zabel@pengutronix.de>,
Linus Walleij <linus.walleij@linaro.org>,
Arnd Bergmann <arnd@arndb.de>,
stefan@agner.ch, pmeerw@pmeerw.net, pebolle@tiscali.nl,
peter@hurleysoftware.com, andy.shevchenko@gmail.com,
cw00.choi@samsung.com, Russell King <linux@arm.linux.org.uk>,
Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Jonathan Corbet <corbet@lwn.net>, Pawel Moll <pawel.moll@arm.com>,
Mark Rutland <mark.rutland@arm.com>,
Ian Campbell <ijc+devicetree@hellion.org.uk>,
Kumar Gala <galak@codeaurora.org>,
Thomas Gleixner <tglx@linutronix.de>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Jiri Slaby <jslaby@suse.cz>,
Andrew Morton <akpm@linux-foundation.org>,
"David S. Miller" <davem@davemloft.net>,
Mauro Carvalho Chehab <mchehab@osg.samsung.com>,
Joe Perches <joe@perches.com>, Antti Palosaari <crope@iki.fi>,
Tejun Heo <tj@kernel.org>, Will Deacon <will.deacon@arm.com>,
Nikolay Borisov <Nikolay.Borisov@arm.com>,
Rusty Russell <rusty@rustcorp.com.au>,
Kees Cook <keescook@chromium.org>, Michal Marek <mmarek@suse.cz>,
linux-doc@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, devicetree@vger.kernel.org,
linux-gpio@vger.kernel.org, linux-serial@vger.ke
Subject: [PATCH v4 06/15] drivers: reset: Add STM32 reset driver
Date: Tue, 31 Mar 2015 18:24:47 +0200 [thread overview]
Message-ID: <1427819096-31109-7-git-send-email-mcoquelin.stm32@gmail.com> (raw)
In-Reply-To: <1427819096-31109-1-git-send-email-mcoquelin.stm32@gmail.com>
The STM32 MCUs family IPs can be reset by accessing some registers
from the RCC block.
The list of available reset lines is documented in the DT bindings.
Tested-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com>
---
drivers/reset/Makefile | 1 +
drivers/reset/reset-stm32.c | 124 ++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 125 insertions(+)
create mode 100644 drivers/reset/reset-stm32.c
diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile
index 157d421..aed12d1 100644
--- a/drivers/reset/Makefile
+++ b/drivers/reset/Makefile
@@ -1,5 +1,6 @@
obj-$(CONFIG_RESET_CONTROLLER) += core.o
obj-$(CONFIG_ARCH_SOCFPGA) += reset-socfpga.o
obj-$(CONFIG_ARCH_BERLIN) += reset-berlin.o
+obj-$(CONFIG_ARCH_STM32) += reset-stm32.o
obj-$(CONFIG_ARCH_SUNXI) += reset-sunxi.o
obj-$(CONFIG_ARCH_STI) += sti/
diff --git a/drivers/reset/reset-stm32.c b/drivers/reset/reset-stm32.c
new file mode 100644
index 0000000..2c41858
--- /dev/null
+++ b/drivers/reset/reset-stm32.c
@@ -0,0 +1,124 @@
+/*
+ * Copyright (C) Maxime Coquelin 2015
+ * Author: Maxime Coquelin <mcoquelin.stm32@gmail.com>
+ * License terms: GNU General Public License (GPL), version 2
+ *
+ * Heavily based on sunxi driver from Maxime Ripard.
+ */
+
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/reset-controller.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+
+struct stm32_reset_data {
+ spinlock_t lock;
+ void __iomem *membase;
+ struct reset_controller_dev rcdev;
+};
+
+static int stm32_reset_assert(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ struct stm32_reset_data *data = container_of(rcdev,
+ struct stm32_reset_data,
+ rcdev);
+ int bank = id / BITS_PER_LONG;
+ int offset = id % BITS_PER_LONG;
+ unsigned long flags;
+ u32 reg;
+
+ spin_lock_irqsave(&data->lock, flags);
+
+ reg = readl_relaxed(data->membase + (bank * 4));
+ writel_relaxed(reg | BIT(offset), data->membase + (bank * 4));
+
+ spin_unlock_irqrestore(&data->lock, flags);
+
+ return 0;
+}
+
+static int stm32_reset_deassert(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ struct stm32_reset_data *data = container_of(rcdev,
+ struct stm32_reset_data,
+ rcdev);
+ int bank = id / BITS_PER_LONG;
+ int offset = id % BITS_PER_LONG;
+ unsigned long flags;
+ u32 reg;
+
+ spin_lock_irqsave(&data->lock, flags);
+
+ reg = readl_relaxed(data->membase + (bank * 4));
+ writel_relaxed(reg & ~BIT(offset), data->membase + (bank * 4));
+
+ spin_unlock_irqrestore(&data->lock, flags);
+
+ return 0;
+}
+
+static struct reset_control_ops stm32_reset_ops = {
+ .assert = stm32_reset_assert,
+ .deassert = stm32_reset_deassert,
+};
+
+static const struct of_device_id stm32_reset_dt_ids[] = {
+ { .compatible = "st,stm32-rcc", },
+ { /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, sstm32_reset_dt_ids);
+
+static int stm32_reset_probe(struct platform_device *pdev)
+{
+ struct stm32_reset_data *data;
+ struct resource *res;
+
+ data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ data->membase = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(data->membase))
+ return PTR_ERR(data->membase);
+
+ spin_lock_init(&data->lock);
+
+ data->rcdev.owner = THIS_MODULE;
+ data->rcdev.nr_resets = resource_size(res) * 8;
+ data->rcdev.ops = &stm32_reset_ops;
+ data->rcdev.of_node = pdev->dev.of_node;
+
+ return reset_controller_register(&data->rcdev);
+}
+
+static int stm32_reset_remove(struct platform_device *pdev)
+{
+ struct stm32_reset_data *data = platform_get_drvdata(pdev);
+
+ reset_controller_unregister(&data->rcdev);
+
+ return 0;
+}
+
+static struct platform_driver stm32_reset_driver = {
+ .probe = stm32_reset_probe,
+ .remove = stm32_reset_remove,
+ .driver = {
+ .name = "stm32-rcc-reset",
+ .of_match_table = stm32_reset_dt_ids,
+ },
+};
+module_platform_driver(stm32_reset_driver);
+
+MODULE_AUTHOR("Maxime Coquelin <maxime.coquelin@gmail.com>");
+MODULE_DESCRIPTION("STM32 MCUs Reset Controller Driver");
+MODULE_LICENSE("GPL");
--
1.9.1
next prev parent reply other threads:[~2015-03-31 16:24 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-31 16:24 [PATCH v4 00/15] Add support to STMicroelectronics STM32 family Maxime Coquelin
2015-03-31 16:24 ` [PATCH v4 01/15] scripts: link-vmlinux: Don't pass page offset to kallsyms if XIP Kernel Maxime Coquelin
2015-03-31 16:24 ` [PATCH v4 02/15] ARM: ARMv7-M: Enlarge vector table up to 256 entries Maxime Coquelin
2015-03-31 16:24 ` [PATCH v4 03/15] dt-bindings: Document the ARM System timer bindings Maxime Coquelin
2015-03-31 16:24 ` [PATCH v4 04/15] clocksource/drivers: Add ARM System timer driver Maxime Coquelin
2015-03-31 16:24 ` [PATCH v4 05/15] dt-bindings: Document the STM32 reset bindings Maxime Coquelin
2015-04-01 9:05 ` Philipp Zabel
[not found] ` <1427879123.3638.1.camel-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
2015-04-01 9:27 ` Maxime Coquelin
2015-04-01 16:32 ` Rob Herring
2015-03-31 16:24 ` Maxime Coquelin [this message]
2015-04-01 9:05 ` [PATCH v4 06/15] drivers: reset: Add STM32 reset driver Philipp Zabel
2015-03-31 16:24 ` [PATCH v4 07/15] dt-bindings: Document the STM32 timer bindings Maxime Coquelin
2015-03-31 16:24 ` [PATCH v4 08/15] clockevents/drivers: Add STM32 Timer driver Maxime Coquelin
2015-03-31 16:24 ` [PATCH v4 09/15] dt-bindings: Document the STM32 USART bindings Maxime Coquelin
2015-03-31 16:24 ` [PATCH v4 10/15] serial: stm32-usart: Add STM32 USART Driver Maxime Coquelin
2015-03-31 16:45 ` Andy Shevchenko
2015-04-01 8:36 ` Maxime Coquelin
2015-03-31 16:24 ` [PATCH v4 11/15] ARM: Add STM32 family machine Maxime Coquelin
2015-03-31 16:24 ` [PATCH v4 12/15] ARM: dts: Add ARM System timer as clockevent in armv7m Maxime Coquelin
2015-03-31 16:24 ` [PATCH v4 13/15] ARM: dts: Introduce STM32F429 MCU Maxime Coquelin
2015-03-31 16:24 ` [PATCH v4 14/15] ARM: configs: Add STM32 defconfig Maxime Coquelin
[not found] ` <1427819096-31109-1-git-send-email-mcoquelin.stm32-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2015-03-31 16:24 ` [PATCH v4 15/15] MAINTAINERS: Add entry for STM32 MCUs Maxime Coquelin
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