On Thu, Jul 21, 2016 at 5:19 AM, <gabriel.fernandez@xxxxxx> wrote: > From: Maxime Coquelin <mcoquelin.stm32@xxxxxxxxx> > > 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. > > Signed-off-by: Maxime Coquelin <mcoquelin.stm32@xxxxxxxxx> > Signed-off-by: Gabriel Fernandez <gabriel.fernandez@xxxxxx> > --- > drivers/reset/Makefile | 1 + > drivers/reset/reset-stm32.c | 113 ++++++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 114 insertions(+) > create mode 100644 drivers/reset/reset-stm32.c > > diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile > index 5d65a93..64ebb0c 100644 > --- a/drivers/reset/Makefile > +++ b/drivers/reset/Makefile > @@ -4,6 +4,7 @@ obj-$(CONFIG_ARCH_SOCFPGA) += reset-socfpga.o > obj-$(CONFIG_ARCH_BERLIN) += reset-berlin.o > obj-$(CONFIG_MACH_PISTACHIO) += reset-pistachio.o > obj-$(CONFIG_ARCH_MESON) += reset-meson.o > +obj-$(CONFIG_ARCH_STM32) += reset-stm32.o In my tree, this Kconfig ARCH_STM32 is a bool, so... > obj-$(CONFIG_ARCH_SUNXI) += reset-sunxi.o > obj-$(CONFIG_ARCH_STI) += sti/ > obj-$(CONFIG_ARCH_HISI) += hisilicon/ > diff --git a/drivers/reset/reset-stm32.c b/drivers/reset/reset-stm32.c > new file mode 100644 > index 0000000..993af2a > --- /dev/null > +++ b/drivers/reset/reset-stm32.c > @@ -0,0 +1,113 @@ > +/* > + * Copyright (C) Maxime Coquelin 2015 > + * Author: Maxime Coquelin <mcoquelin.stm32@xxxxxxxxx>_ > + * 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> ...we probably don't need module.h here or any of the other MODULE_<blah> tags/macros either. Use the builtin for the register and all should be good. Thanks, Paul. -- > +#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(data->membase + (bank * 4)); > + writel(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(data->membase + (bank * 4)); > + writel(reg & ~BIT(offset), data->membase + (bank * 4)); > + > + spin_unlock_irqrestore(&data->lock, flags); > + > + return 0; > +} > + > +static const 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 */ }, > +}; > + > +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 devm_reset_controller_register(&pdev->dev, &data->rcdev); > +} > + > +static struct platform_driver stm32_reset_driver = { > + .probe = stm32_reset_probe, > + .driver = { > + .name = "stm32-rcc-reset", > + .of_match_table = stm32_reset_dt_ids, > + }, > +}; > +module_platform_driver(stm32_reset_driver); > + > +MODULE_AUTHOR("Maxime Coquelin <maxime.coquelin@xxxxxxxxx>"); > +MODULE_DESCRIPTION("STM32 MCUs Reset Controller Driver"); > +MODULE_LICENSE("GPL"); > -- > 1.9.1 > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html