Hi Andrew, is there (going to be) as stable branch I can base these on, or should I just wait until the prerequisite patches appear in arm-soc/for-next? Am Donnerstag, den 27.10.2016, 16:49 -0500 schrieb Andrew F. Davis: > Some TI Keystone family of SoCs contain a system controller (like the > Power Management Micro Controller (PMMC) on K2G SoCs) that manage the > low-level device control (like clocks, resets etc) for the various > hardware modules present on the SoC. These device control operations > are provided to the host processor OS through a communication protocol > called the TI System Control Interface (TI SCI) protocol. > > This patch adds a reset driver that communicates to the system > controller over the TI SCI protocol for performing reset management > of various devices present on the SoC. Various reset functionalities > are achieved by the means of different TI SCI device operations > provided by the TI SCI framework. > > Signed-off-by: Andrew F. Davis <afd@xxxxxx> > [s-anna@xxxxxx: documentation changes, revised commit message] > Signed-off-by: Suman Anna <s-anna@xxxxxx> > Signed-off-by: Nishanth Menon <nm@xxxxxx> > --- > MAINTAINERS | 1 + > drivers/reset/Kconfig | 9 ++ > drivers/reset/Makefile | 1 + > drivers/reset/reset-ti-sci.c | 262 +++++++++++++++++++++++++++++++++++++++++++ > 4 files changed, 273 insertions(+) > create mode 100644 drivers/reset/reset-ti-sci.c > > diff --git a/MAINTAINERS b/MAINTAINERS > index accf991..b93d91a 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -11901,6 +11901,7 @@ F: include/dt-bindings/clock/k2g.h > F: drivers/clk/keystone/sci-clk.c > F: Documentation/devicetree/bindings/reset/ti,sci-reset.txt > F: include/dt-bindings/reset/k2g.h > +F: drivers/reset/reset-ti-sci.c > > THANKO'S RAREMONO AM/FM/SW RADIO RECEIVER USB DRIVER > M: Hans Verkuil <hverkuil@xxxxxxxxx> > diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig > index 06d9fa2..4c21c9d 100644 > --- a/drivers/reset/Kconfig > +++ b/drivers/reset/Kconfig > @@ -66,6 +66,15 @@ config RESET_SUNXI > help > This enables the reset driver for Allwinner SoCs. > > +config RESET_TI_SCI > + tristate "TI System Control Interface (TI-SCI) reset driver" > + depends on RESET_CONTROLLER > + depends on TI_SCI_PROTOCOL > + help > + This enables the reset driver support over TI System Control Interface > + available on some new TI SoCs. If you wish to use reset resources > + managed by the TI System Controller, say Y here. Otherwise, say N. > + > config TI_SYSCON_RESET > tristate "TI SYSCON Reset Driver" > depends on HAS_IOMEM > diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile > index bbe7026..36321f2 100644 > --- a/drivers/reset/Makefile > +++ b/drivers/reset/Makefile > @@ -10,6 +10,7 @@ obj-$(CONFIG_RESET_PISTACHIO) += reset-pistachio.o > obj-$(CONFIG_RESET_SOCFPGA) += reset-socfpga.o > obj-$(CONFIG_RESET_STM32) += reset-stm32.o > obj-$(CONFIG_RESET_SUNXI) += reset-sunxi.o > +obj-$(CONFIG_RESET_TI_SCI) += reset-ti-sci.o > obj-$(CONFIG_TI_SYSCON_RESET) += reset-ti-syscon.o > obj-$(CONFIG_RESET_UNIPHIER) += reset-uniphier.o > obj-$(CONFIG_RESET_ZYNQ) += reset-zynq.o > diff --git a/drivers/reset/reset-ti-sci.c b/drivers/reset/reset-ti-sci.c > new file mode 100644 > index 0000000..42ccf12 > --- /dev/null > +++ b/drivers/reset/reset-ti-sci.c > @@ -0,0 +1,262 @@ > +/* > + * Texas Instrument's System Control Interface (TI-SCI) reset driver > + * > + * Copyright (C) 2015-2016 Texas Instruments Incorporated - http://www.ti.com/ > + * Andrew F. Davis <afd@xxxxxx> > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License version 2 as > + * published by the Free Software Foundation. > + * > + * This program is distributed "as is" WITHOUT ANY WARRANTY of any > + * kind, whether express or implied; without even the implied warranty > + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + */ > + > +#include <linux/idr.h> > +#include <linux/module.h> > +#include <linux/of.h> > +#include <linux/platform_device.h> > +#include <linux/reset-controller.h> > +#include <linux/soc/ti/ti_sci_protocol.h> > + > +/** > + * struct ti_sci_reset_control - reset control structure > + * @dev_id: SoC-specific device identifier > + * @reset_mask: reset mask to use for toggling reset > + */ > +struct ti_sci_reset_control { > + u32 dev_id; > + u32 reset_mask; > +}; > + > +/** > + * struct ti_sci_reset_data - reset controller information structure > + * @rcdev: reset controller entity > + * @dev: reset controller device pointer > + * @sci: TI SCI handle used for communication with system controller > + * @idr: idr structure for mapping ids to reset control structures > + */ > +struct ti_sci_reset_data { > + struct reset_controller_dev rcdev; > + struct device *dev; > + const struct ti_sci_handle *sci; > + struct idr idr; > +}; > + > +#define to_ti_sci_reset_data(p) \ > + container_of((p), struct ti_sci_reset_data, rcdev) > + > +/** > + * ti_sci_reset_set() - program a device's reset > + * @rcdev: reset controller entity > + * @id: ID of the reset to toggle > + * @assert: boolean flag to indicate assert or deassert > + * > + * This is a common internal function used to assert or deassert a device's > + * reset using the TI SCI protocol. The device's reset is asserted if the > + * @assert argument is true, or deasserted if @assert argument is false. > + * The mechanism itself is a read-modify-write procedure, the current device > + * reset register is read using a TI SCI device operation, the new value is > + * set or un-set using the reset's mask, and the new reset value written by > + * using another TI SCI device operation. > + * > + * Return: 0 for successful request, else a corresponding error value > + */ > +static int ti_sci_reset_set(struct reset_controller_dev *rcdev, > + unsigned long id, bool assert) > +{ > + struct ti_sci_reset_data *data = to_ti_sci_reset_data(rcdev); > + const struct ti_sci_handle *sci = data->sci; > + const struct ti_sci_dev_ops *dev_ops = &sci->ops.dev_ops; > + struct ti_sci_reset_control *control; > + u32 reset_state; > + int ret; > + > + control = idr_find(&data->idr, id); > + if (!control) > + return -EINVAL; > + > + ret = dev_ops->get_device_resets(sci, control->dev_id, > + &reset_state); > + if (ret) > + return ret; > + > + if (assert) > + reset_state |= control->reset_mask; > + else > + reset_state &= ~control->reset_mask; > + > + return dev_ops->set_device_resets(sci, control->dev_id, > + reset_state); Without any locking? Maybe the read-modify-write could just be moved one level down with an update_bits type of callback in the ti_sci_dev_ops. > +} > + > +/** > + * ti_sci_reset_assert() - assert device reset > + * @rcdev: reset controller entity > + * @id: ID of the reset to be asserted > + * > + * This function implements the reset driver op to assert a device's reset > + * using the TI SCI protocol. This invokes the function ti_sci_reset_set() > + * with the corresponding parameters as passed in, but with the @assert > + * argument set to true for asserting the reset. > + * > + * Return: 0 for successful request, else a corresponding error value > + */ > +static int ti_sci_reset_assert(struct reset_controller_dev *rcdev, > + unsigned long id) > +{ > + return ti_sci_reset_set(rcdev, id, true); > +} > + > +/** > + * ti_sci_reset_deassert() - deassert device reset > + * @rcdev: reset controller entity > + * @id: ID of the reset to be deasserted > + * > + * This function implements the reset driver op to deassert a device's reset > + * using the TI SCI protocol. This invokes the function ti_sci_reset_set() > + * with the corresponding parameters as passed in, but with the @assert > + * argument set to false for deasserting the reset. > + * > + * Return: 0 for successful request, else a corresponding error value > + */ > +static int ti_sci_reset_deassert(struct reset_controller_dev *rcdev, > + unsigned long id) > +{ > + return ti_sci_reset_set(rcdev, id, false); > +} > + > +/** > + * ti_sci_reset_status() - check device reset status > + * @rcdev: reset controller entity > + * @id: ID of reset to be checked > + * > + * This function implements the reset driver op to return the status of a > + * device's reset using the TI SCI protocol. The reset register value is read > + * by invoking the TI SCI device opertation .get_device_resets(), and the > + * status of the specific reset is extracted and returned using this reset's > + * reset mask. > + * > + * Return: 0 if reset is deasserted, or a non-zero value if reset is asserted > + */ > +static int ti_sci_reset_status(struct reset_controller_dev *rcdev, > + unsigned long id) > +{ > + struct ti_sci_reset_data *data = to_ti_sci_reset_data(rcdev); > + const struct ti_sci_handle *sci = data->sci; > + const struct ti_sci_dev_ops *dev_ops = &sci->ops.dev_ops; > + struct ti_sci_reset_control *control; > + u32 reset_state; > + int ret; > + > + control = idr_find(&data->idr, id); > + if (!control) > + return -EINVAL; > + > + ret = dev_ops->get_device_resets(sci, control->dev_id, > + &reset_state); > + if (ret) > + return ret; > + > + return reset_state & control->reset_mask; > +} > + > +static struct reset_control_ops ti_sci_reset_ops = { > + .assert = ti_sci_reset_assert, > + .deassert = ti_sci_reset_deassert, > + .status = ti_sci_reset_status, > +}; > + > +/** > + * ti_sci_reset_of_xlate() - translate a set of OF arguments to a reset ID > + * @rcdev: reset controller entity > + * @reset_spec: OF reset argument specifier > + * > + * This function performs the translation of the reset argument specifier > + * values defined in a reset consumer device node. The function allocates a > + * reset control structure for that device reset, and will be used by the > + * driver for performing any reset functions on that reset. An idr structure > + * is allocated and used to map to the reset control structure. This idr > + * is used by the driver to do reset lookups. > + * > + * Return: 0 for successful request, else a corresponding error value > + */ > +static int ti_sci_reset_of_xlate(struct reset_controller_dev *rcdev, > + const struct of_phandle_args *reset_spec) > +{ > + struct ti_sci_reset_data *data = to_ti_sci_reset_data(rcdev); > + struct ti_sci_reset_control *control; > + > + if (WARN_ON(reset_spec->args_count != rcdev->of_reset_n_cells)) > + return -EINVAL; > + > + control = devm_kzalloc(data->dev, sizeof(*control), GFP_KERNEL); > + if (!control) > + return -ENOMEM; > + > + control->dev_id = reset_spec->args[0]; > + control->reset_mask = reset_spec->args[1]; > + > + return idr_alloc(&data->idr, control, 0, 0, GFP_KERNEL); > +} > + > +static const struct of_device_id ti_sci_reset_of_match[] = { > + { .compatible = "ti,sci-reset", }, > + { /* sentinel */ }, > +}; > +MODULE_DEVICE_TABLE(of, ti_sci_reset_of_match); > + > +static int ti_sci_reset_probe(struct platform_device *pdev) > +{ > + struct ti_sci_reset_data *data; > + > + if (!pdev->dev.of_node) > + return -ENODEV; > + > + data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); > + if (!data) > + return -ENOMEM; > + > + data->sci = devm_ti_sci_get_handle(&pdev->dev); > + if (IS_ERR(data->sci)) > + return PTR_ERR(data->sci); > + > + data->rcdev.ops = &ti_sci_reset_ops; > + data->rcdev.owner = THIS_MODULE; > + data->rcdev.of_node = pdev->dev.of_node; > + data->rcdev.of_reset_n_cells = 2; > + data->rcdev.of_xlate = ti_sci_reset_of_xlate; > + data->dev = &pdev->dev; > + idr_init(&data->idr); > + > + platform_set_drvdata(pdev, data); > + > + return reset_controller_register(&data->rcdev); > +} > + > +static int ti_sci_reset_remove(struct platform_device *pdev) > +{ > + struct ti_sci_reset_data *data = platform_get_drvdata(pdev); > + > + reset_controller_unregister(&data->rcdev); > + > + idr_destroy(&data->idr); > + > + return 0; > +} > + > +static struct platform_driver ti_sci_reset_driver = { > + .probe = ti_sci_reset_probe, > + .remove = ti_sci_reset_remove, > + .driver = { > + .name = "ti-sci-reset", > + .of_match_table = ti_sci_reset_of_match, > + }, > +}; > +module_platform_driver(ti_sci_reset_driver); > + > +MODULE_AUTHOR("Andrew F. Davis <afd@xxxxxx>"); > +MODULE_DESCRIPTION("TI System Control Interface (TI SCI) Reset driver"); > +MODULE_LICENSE("GPL v2"); regards Philipp -- 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
