| Message ID | 1413311749-13948-2-git-send-email-carlo@caione.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Carlo, On Tue, Oct 14, 2014 at 08:35:47PM +0200, Carlo Caione wrote: > This patch adds support for the reset controller found on the Amlogic > MesonX SoCs. For several devices in the AO (Always-On) power domain, it > is possible to reset them by programming a specific bit in a register. > > Signed-off-by: Carlo Caione <carlo@caione.org> > --- > drivers/reset/Makefile | 1 + > drivers/reset/reset-meson.c | 142 ++++++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 143 insertions(+) > create mode 100644 drivers/reset/reset-meson.c > > diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile > index 60fed3d..74f2372 100644 > --- a/drivers/reset/Makefile > +++ b/drivers/reset/Makefile > @@ -1,4 +1,5 @@ > obj-$(CONFIG_RESET_CONTROLLER) += core.o > obj-$(CONFIG_ARCH_SOCFPGA) += reset-socfpga.o > obj-$(CONFIG_ARCH_SUNXI) += reset-sunxi.o > +obj-$(CONFIG_ARCH_MESON) += reset-meson.o > obj-$(CONFIG_ARCH_STI) += sti/ > diff --git a/drivers/reset/reset-meson.c b/drivers/reset/reset-meson.c > new file mode 100644 > index 0000000..59b58e4 > --- /dev/null > +++ b/drivers/reset/reset-meson.c > @@ -0,0 +1,142 @@ > +/* > + * Copyright 2014 Carlo Caione <carlo@caione.org> > + * > + * based on > + * Steffen Trumtrar Reset Controller driver That doesn't sound right. Do you mean socfpga-reset? > + * Copyright 2014 Steffen Trumtrar > + * > + * Steffen Trumtrar <s.trumtrar@pengutronix.de> Could be combined into a single line. > + * 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; either version 2 of the License, or > + * (at your option) any later version. > + */ > + > +#include <linux/err.h> > +#include <linux/io.h> > +#include <linux/module.h> > +#include <linux/of.h> > +#include <linux/platform_device.h> > +#include <linux/reset-controller.h> > +#include <linux/spinlock.h> > +#include <linux/types.h> > + > +#define MESON_RST_OFFSET 0x00 If there is only one register, I see no need for this. > +struct meson_reset_data { > + spinlock_t lock; > + void __iomem *membase; > + struct reset_controller_dev rcdev; > +}; > + > +static int meson_reset_assert(struct reset_controller_dev *rcdev, > + unsigned long id) > +{ > + struct meson_reset_data *data = container_of(rcdev, > + struct meson_reset_data, > + rcdev); > + unsigned long flags; > + u32 reg; > + > + spin_lock_irqsave(&data->lock, flags); > + > + reg = readl(data->membase + MESON_RST_OFFSET); > + writel(reg | BIT(id), data->membase + MESON_RST_OFFSET); > + > + spin_unlock_irqrestore(&data->lock, flags); > + > + return 0; > +} > + > +static int meson_reset_deassert(struct reset_controller_dev *rcdev, > + unsigned long id) > +{ > + struct meson_reset_data *data = container_of(rcdev, > + struct meson_reset_data, > + rcdev); > + > + unsigned long flags; > + u32 reg; > + > + spin_lock_irqsave(&data->lock, flags); > + > + reg = readl(data->membase + MESON_RST_OFFSET); > + writel(reg & ~BIT(id), data->membase + MESON_RST_OFFSET); > + > + spin_unlock_irqrestore(&data->lock, flags); > + > + return 0; > +} > + > +static int meson_reset_dev(struct reset_controller_dev *rcdev, unsigned long id) > +{ > + int err; > + > + err = meson_reset_assert(rcdev, id); > + if (err) > + return err; > + > + return meson_reset_deassert(rcdev, id); > +} > + > +static struct reset_control_ops meson_reset_ops = { > + .assert = meson_reset_assert, > + .deassert = meson_reset_deassert, > + .reset = meson_reset_dev, > +}; > + > +static int meson_reset_probe(struct platform_device *pdev) > +{ > + struct meson_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); > + > + platform_set_drvdata(pdev, data); > + > + data->rcdev.owner = THIS_MODULE; > + data->rcdev.nr_resets = BITS_PER_LONG; Are all bits in this registers reset controls (or rather, are you positive there is no bit in this register used by anything else)? > + data->rcdev.ops = &meson_reset_ops; > + data->rcdev.of_node = pdev->dev.of_node; > + > + return reset_controller_register(&data->rcdev); > +} > + > +static int meson_reset_remove(struct platform_device *pdev) > +{ > + struct meson_reset_data *data = platform_get_drvdata(pdev); > + > + reset_controller_unregister(&data->rcdev); > + > + return 0; > +} > + > +static const struct of_device_id meson_reset_dt_ids[] = { > + { .compatible = "amlogic,meson6-rst-mgr-ao", }, > + { /* sentinel */ }, > +}; > + > +static struct platform_driver meson_reset_driver = { > + .probe = meson_reset_probe, > + .remove = meson_reset_remove, > + .driver = { > + .name = "meson-reset", > + .of_match_table = meson_reset_dt_ids, > + }, > +}; > +module_platform_driver(meson_reset_driver); > + > +MODULE_AUTHOR("Carlo Caione <carlo@caione.org>"); > +MODULE_DESCRIPTION("Meson Reset Controller Driver"); > +MODULE_LICENSE("GPL"); > -- > 1.9.1 Other than that, the driver looks good. regards Philipp
On Wed, Oct 15, 2014 at 12:36 AM, Philipp Zabel <pza@pengutronix.de> wrote: > Hi Carlo, Hi Philipp, >> @@ -0,0 +1,142 @@ >> +/* >> + * Copyright 2014 Carlo Caione <carlo@caione.org> >> + * >> + * based on >> + * Steffen Trumtrar Reset Controller driver > > That doesn't sound right. Do you mean socfpga-reset? Yes, I'll change it. >> + * Copyright 2014 Steffen Trumtrar >> + * >> + * Steffen Trumtrar <s.trumtrar@pengutronix.de> > > Could be combined into a single line. Ok >> + * 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; either version 2 of the License, or >> + * (at your option) any later version. >> + */ >> + >> +#include <linux/err.h> >> +#include <linux/io.h> >> +#include <linux/module.h> >> +#include <linux/of.h> >> +#include <linux/platform_device.h> >> +#include <linux/reset-controller.h> >> +#include <linux/spinlock.h> >> +#include <linux/types.h> >> + >> +#define MESON_RST_OFFSET 0x00 > > If there is only one register, I see no need for this. Ok >> + >> + data->rcdev.owner = THIS_MODULE; >> + data->rcdev.nr_resets = BITS_PER_LONG; > > Are all bits in this registers reset controls (or rather, are you > positive there is no bit in this register used by anything else)? I'm not sure to be honest. Probably some other bits is used for power management (I don't have full documentation yet). I'll submit a v3 with a smaller mask for just the bits I'm going to use. > Other than that, the driver looks good. Thank you.
diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile index 60fed3d..74f2372 100644 --- a/drivers/reset/Makefile +++ b/drivers/reset/Makefile @@ -1,4 +1,5 @@ obj-$(CONFIG_RESET_CONTROLLER) += core.o obj-$(CONFIG_ARCH_SOCFPGA) += reset-socfpga.o obj-$(CONFIG_ARCH_SUNXI) += reset-sunxi.o +obj-$(CONFIG_ARCH_MESON) += reset-meson.o obj-$(CONFIG_ARCH_STI) += sti/ diff --git a/drivers/reset/reset-meson.c b/drivers/reset/reset-meson.c new file mode 100644 index 0000000..59b58e4 --- /dev/null +++ b/drivers/reset/reset-meson.c @@ -0,0 +1,142 @@ +/* + * Copyright 2014 Carlo Caione <carlo@caione.org> + * + * based on + * Steffen Trumtrar Reset Controller driver + * + * Copyright 2014 Steffen Trumtrar + * + * Steffen Trumtrar <s.trumtrar@pengutronix.de> + * + * 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; either version 2 of the License, or + * (at your option) any later version. + */ + +#include <linux/err.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/reset-controller.h> +#include <linux/spinlock.h> +#include <linux/types.h> + +#define MESON_RST_OFFSET 0x00 + +struct meson_reset_data { + spinlock_t lock; + void __iomem *membase; + struct reset_controller_dev rcdev; +}; + +static int meson_reset_assert(struct reset_controller_dev *rcdev, + unsigned long id) +{ + struct meson_reset_data *data = container_of(rcdev, + struct meson_reset_data, + rcdev); + unsigned long flags; + u32 reg; + + spin_lock_irqsave(&data->lock, flags); + + reg = readl(data->membase + MESON_RST_OFFSET); + writel(reg | BIT(id), data->membase + MESON_RST_OFFSET); + + spin_unlock_irqrestore(&data->lock, flags); + + return 0; +} + +static int meson_reset_deassert(struct reset_controller_dev *rcdev, + unsigned long id) +{ + struct meson_reset_data *data = container_of(rcdev, + struct meson_reset_data, + rcdev); + + unsigned long flags; + u32 reg; + + spin_lock_irqsave(&data->lock, flags); + + reg = readl(data->membase + MESON_RST_OFFSET); + writel(reg & ~BIT(id), data->membase + MESON_RST_OFFSET); + + spin_unlock_irqrestore(&data->lock, flags); + + return 0; +} + +static int meson_reset_dev(struct reset_controller_dev *rcdev, unsigned long id) +{ + int err; + + err = meson_reset_assert(rcdev, id); + if (err) + return err; + + return meson_reset_deassert(rcdev, id); +} + +static struct reset_control_ops meson_reset_ops = { + .assert = meson_reset_assert, + .deassert = meson_reset_deassert, + .reset = meson_reset_dev, +}; + +static int meson_reset_probe(struct platform_device *pdev) +{ + struct meson_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); + + platform_set_drvdata(pdev, data); + + data->rcdev.owner = THIS_MODULE; + data->rcdev.nr_resets = BITS_PER_LONG; + data->rcdev.ops = &meson_reset_ops; + data->rcdev.of_node = pdev->dev.of_node; + + return reset_controller_register(&data->rcdev); +} + +static int meson_reset_remove(struct platform_device *pdev) +{ + struct meson_reset_data *data = platform_get_drvdata(pdev); + + reset_controller_unregister(&data->rcdev); + + return 0; +} + +static const struct of_device_id meson_reset_dt_ids[] = { + { .compatible = "amlogic,meson6-rst-mgr-ao", }, + { /* sentinel */ }, +}; + +static struct platform_driver meson_reset_driver = { + .probe = meson_reset_probe, + .remove = meson_reset_remove, + .driver = { + .name = "meson-reset", + .of_match_table = meson_reset_dt_ids, + }, +}; +module_platform_driver(meson_reset_driver); + +MODULE_AUTHOR("Carlo Caione <carlo@caione.org>"); +MODULE_DESCRIPTION("Meson Reset Controller Driver"); +MODULE_LICENSE("GPL");
This patch adds support for the reset controller found on the Amlogic MesonX SoCs. For several devices in the AO (Always-On) power domain, it is possible to reset them by programming a specific bit in a register. Signed-off-by: Carlo Caione <carlo@caione.org> --- drivers/reset/Makefile | 1 + drivers/reset/reset-meson.c | 142 ++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 143 insertions(+) create mode 100644 drivers/reset/reset-meson.c