| Message ID | 20170526033214.8081-3-joel@jms.id.au |
|---|---|
| State | New |
| Headers | show |
| Series | reset: Basic reset controller | expand |
On Fri, May 26, 2017 at 6:32 AM, Joel Stanley <joel@jms.id.au> wrote: > This driver is a basic single-register reset controller driver that > supports clearing a single bit in a register. > While this makes sense, I'm wondering if there can be generic interface for this from which we can derive this one and GPIO-based one. > Signed-off-by: Joel Stanley <joel@jms.id.au> > --- > drivers/reset/Kconfig | 6 +++ > drivers/reset/Makefile | 1 + > drivers/reset/reset-basic.c | 109 ++++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 116 insertions(+) > create mode 100644 drivers/reset/reset-basic.c > > diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig > index d21c07ccc94e..980cda887dfe 100644 > --- a/drivers/reset/Kconfig > +++ b/drivers/reset/Kconfig > @@ -28,6 +28,12 @@ config RESET_ATH79 > This enables the ATH79 reset controller driver that supports the > AR71xx SoC reset controller. > > +config RESET_BASIC > + bool "Basic Reset Driver" > + help > + This enables a basic single-register reset controller driver that > + supports clearing a single bit in a register. > + > config RESET_BERLIN > bool "Berlin Reset Driver" if COMPILE_TEST > default ARCH_BERLIN > diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile > index 02a74db94339..e8e8869e098d 100644 > --- a/drivers/reset/Makefile > +++ b/drivers/reset/Makefile > @@ -4,6 +4,7 @@ obj-$(CONFIG_ARCH_STI) += sti/ > obj-$(CONFIG_ARCH_TEGRA) += tegra/ > obj-$(CONFIG_RESET_A10SR) += reset-a10sr.o > obj-$(CONFIG_RESET_ATH79) += reset-ath79.o > +obj-$(CONFIG_RESET_BASIC) += reset-basic.o > obj-$(CONFIG_RESET_BERLIN) += reset-berlin.o > obj-$(CONFIG_RESET_IMX7) += reset-imx7.o > obj-$(CONFIG_RESET_LPC18XX) += reset-lpc18xx.o > diff --git a/drivers/reset/reset-basic.c b/drivers/reset/reset-basic.c > new file mode 100644 > index 000000000000..62a676de9f62 > --- /dev/null > +++ b/drivers/reset/reset-basic.c > @@ -0,0 +1,109 @@ > +/* > + * Copyright 2017 IBM Corperation > + * > + * Joel Stanley <joel@jms.id.au> > + * > + * 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/delay.h> > +#include <linux/init.h> > +#include <linux/of.h> > +#include <linux/of_address.h> > +#include <linux/platform_device.h> > +#include <linux/regmap.h> > +#include <linux/mfd/syscon.h> > +#include <linux/reset-controller.h> > + > +#define to_basic_reset_priv(p) \ > + container_of((p), struct basic_reset_priv, rcdev) > + > +struct basic_reset_priv { > + struct regmap *regmap; > + struct reset_controller_dev rcdev; > + u32 reg; > +}; > + > +static int basic_reset_assert(struct reset_controller_dev *rcdev, > + unsigned long id) > +{ > + struct basic_reset_priv *priv = to_basic_reset_priv(rcdev); > + u32 mask = BIT(id); > + > + regmap_update_bits(priv->regmap, priv->reg, mask, mask); > + > + return 0; > +} > + > +static int basic_reset_deassert(struct reset_controller_dev *rcdev, > + unsigned long id) > +{ > + struct basic_reset_priv *priv = to_basic_reset_priv(rcdev); > + u32 mask = BIT(id); > + > + regmap_update_bits(priv->regmap, priv->reg, mask, 0); > + > + return 0; > +} > + > +static int basic_reset_status(struct reset_controller_dev *rcdev, > + unsigned long id) > +{ > + struct basic_reset_priv *priv = to_basic_reset_priv(rcdev); > + u32 mask = BIT(id); > + u32 val; > + > + regmap_read(priv->regmap, priv->reg, &val); > + > + return !!(val & mask); > +} > + > +static const struct reset_control_ops basic_reset_ops = { > + .assert = basic_reset_assert, > + .deassert = basic_reset_deassert, > + .status = basic_reset_status, > +}; > + > +static int basic_reset_probe(struct platform_device *pdev) > +{ > + struct device_node *parent_np = of_get_parent(pdev->dev.of_node); > + struct basic_reset_priv *priv; > + int ret; > + > + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); > + if (!priv) > + return -ENOMEM; > + > + priv->regmap = syscon_node_to_regmap(parent_np); > + of_node_put(parent_np); > + if (IS_ERR(priv->regmap)) > + return PTR_ERR(priv->regmap); > + > + ret = of_property_read_u32(pdev->dev.of_node, "reg", &priv->reg); > + if (ret) > + return ret; > + > + priv->rcdev.owner = THIS_MODULE; > + priv->rcdev.ops = &basic_reset_ops; > + priv->rcdev.of_node = pdev->dev.of_node; > + priv->rcdev.nr_resets = 32; > + > + return reset_controller_register(&priv->rcdev); > +} > + > +static const struct of_device_id basic_reset_dt_match[] = { > + { .compatible = "reset-basic" }, > + { }, > +}; > + > +static struct platform_driver basic_reset_driver = { > + .probe = basic_reset_probe, > + .driver = { > + .name = "basic-reset", > + .of_match_table = basic_reset_dt_match, > + }, > +}; > +builtin_platform_driver(basic_reset_driver); > -- > 2.11.0 > -- With Best Regards, Andy Shevchenko -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, May 29, 2017 at 1:24 PM, Joel Stanley <joel@jms.id.au> wrote: > On Sun, May 28, 2017 at 12:41 AM, Andy Shevchenko > <andy.shevchenko@gmail.com> wrote: >> On Fri, May 26, 2017 at 6:32 AM, Joel Stanley <joel@jms.id.au> wrote: >>> This driver is a basic single-register reset controller driver that >>> supports clearing a single bit in a register. >>> >> >> While this makes sense, I'm wondering if there can be generic >> interface for this from which we can derive this one and GPIO-based >> one. > > Do we have a GPIO based one already? I couldn't find it. No, we haven't. > Having a think, it would be a very similar looking driver, but with > little shared code. The context struct would contain a gpio pointer > instead of regmap, probe would request a GPIO instead of a regmap and > the assert/deassert/status callbacks would be gpiod_ calls. > > Given this is four of the four functions in this driver, do you think would be > better off with two small drivers? Fair enough. Sounds like independent drivers for now is a good approach, though it's up to maintainer. -- With Best Regards, Andy Shevchenko -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig index d21c07ccc94e..980cda887dfe 100644 --- a/drivers/reset/Kconfig +++ b/drivers/reset/Kconfig @@ -28,6 +28,12 @@ config RESET_ATH79 This enables the ATH79 reset controller driver that supports the AR71xx SoC reset controller. +config RESET_BASIC + bool "Basic Reset Driver" + help + This enables a basic single-register reset controller driver that + supports clearing a single bit in a register. + config RESET_BERLIN bool "Berlin Reset Driver" if COMPILE_TEST default ARCH_BERLIN diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile index 02a74db94339..e8e8869e098d 100644 --- a/drivers/reset/Makefile +++ b/drivers/reset/Makefile @@ -4,6 +4,7 @@ obj-$(CONFIG_ARCH_STI) += sti/ obj-$(CONFIG_ARCH_TEGRA) += tegra/ obj-$(CONFIG_RESET_A10SR) += reset-a10sr.o obj-$(CONFIG_RESET_ATH79) += reset-ath79.o +obj-$(CONFIG_RESET_BASIC) += reset-basic.o obj-$(CONFIG_RESET_BERLIN) += reset-berlin.o obj-$(CONFIG_RESET_IMX7) += reset-imx7.o obj-$(CONFIG_RESET_LPC18XX) += reset-lpc18xx.o diff --git a/drivers/reset/reset-basic.c b/drivers/reset/reset-basic.c new file mode 100644 index 000000000000..62a676de9f62 --- /dev/null +++ b/drivers/reset/reset-basic.c @@ -0,0 +1,109 @@ +/* + * Copyright 2017 IBM Corperation + * + * Joel Stanley <joel@jms.id.au> + * + * 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/delay.h> +#include <linux/init.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> +#include <linux/mfd/syscon.h> +#include <linux/reset-controller.h> + +#define to_basic_reset_priv(p) \ + container_of((p), struct basic_reset_priv, rcdev) + +struct basic_reset_priv { + struct regmap *regmap; + struct reset_controller_dev rcdev; + u32 reg; +}; + +static int basic_reset_assert(struct reset_controller_dev *rcdev, + unsigned long id) +{ + struct basic_reset_priv *priv = to_basic_reset_priv(rcdev); + u32 mask = BIT(id); + + regmap_update_bits(priv->regmap, priv->reg, mask, mask); + + return 0; +} + +static int basic_reset_deassert(struct reset_controller_dev *rcdev, + unsigned long id) +{ + struct basic_reset_priv *priv = to_basic_reset_priv(rcdev); + u32 mask = BIT(id); + + regmap_update_bits(priv->regmap, priv->reg, mask, 0); + + return 0; +} + +static int basic_reset_status(struct reset_controller_dev *rcdev, + unsigned long id) +{ + struct basic_reset_priv *priv = to_basic_reset_priv(rcdev); + u32 mask = BIT(id); + u32 val; + + regmap_read(priv->regmap, priv->reg, &val); + + return !!(val & mask); +} + +static const struct reset_control_ops basic_reset_ops = { + .assert = basic_reset_assert, + .deassert = basic_reset_deassert, + .status = basic_reset_status, +}; + +static int basic_reset_probe(struct platform_device *pdev) +{ + struct device_node *parent_np = of_get_parent(pdev->dev.of_node); + struct basic_reset_priv *priv; + int ret; + + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + priv->regmap = syscon_node_to_regmap(parent_np); + of_node_put(parent_np); + if (IS_ERR(priv->regmap)) + return PTR_ERR(priv->regmap); + + ret = of_property_read_u32(pdev->dev.of_node, "reg", &priv->reg); + if (ret) + return ret; + + priv->rcdev.owner = THIS_MODULE; + priv->rcdev.ops = &basic_reset_ops; + priv->rcdev.of_node = pdev->dev.of_node; + priv->rcdev.nr_resets = 32; + + return reset_controller_register(&priv->rcdev); +} + +static const struct of_device_id basic_reset_dt_match[] = { + { .compatible = "reset-basic" }, + { }, +}; + +static struct platform_driver basic_reset_driver = { + .probe = basic_reset_probe, + .driver = { + .name = "basic-reset", + .of_match_table = basic_reset_dt_match, + }, +}; +builtin_platform_driver(basic_reset_driver);
This driver is a basic single-register reset controller driver that supports clearing a single bit in a register. Signed-off-by: Joel Stanley <joel@jms.id.au> --- drivers/reset/Kconfig | 6 +++ drivers/reset/Makefile | 1 + drivers/reset/reset-basic.c | 109 ++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 116 insertions(+) create mode 100644 drivers/reset/reset-basic.c -- 2.11.0 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html