diff options
| -rw-r--r-- | doc/device-tree-bindings/reset/ti,sci-reset.txt | 54 | ||||
| -rw-r--r-- | drivers/reset/Kconfig | 8 | ||||
| -rw-r--r-- | drivers/reset/Makefile | 1 | ||||
| -rw-r--r-- | drivers/reset/reset-ti-sci.c | 206 |
4 files changed, 269 insertions, 0 deletions
diff --git a/doc/device-tree-bindings/reset/ti,sci-reset.txt b/doc/device-tree-bindings/reset/ti,sci-reset.txt new file mode 100644 index 0000000..e7e2d13 --- /dev/null +++ b/doc/device-tree-bindings/reset/ti,sci-reset.txt @@ -0,0 +1,54 @@ +Texas Instruments TI SCI Reset Controller +========================================= + +Some TI SoCs contain a system controller (like the SYSFW, etc...) that is +responsible for controlling the state of the IPs that are present. +Communication between the host processor running an OS and the system +controller happens through a protocol known as TI SCI [1]. + +[1] http://processors.wiki.ti.com/index.php/TISCI + +Reset Controller Node +===================== +The reset controller node represents the resets of various hardware modules +present on the SoC managed by the SYSFW. Because this relies on the TI SCI +protocol to communicate with the SYSFW it must be a child of the sysfw node. + +Required Properties: +-------------------- + - compatible: Must be "ti,sci-reset" + - #reset-cells: Must be 2. Please see the reset consumer node below for + usage details. + +Example (AM65x): +---------------- + sysfw: sysfw { + compatible = "ti,am654-system-controller"; + ... + k3_reset: reset-controller { + compatible = "ti,sci-reset"; + #reset-cells = <2>; + }; + }; + +Reset Consumers +=============== +Each of the reset consumer nodes should have the following properties, +in addition to their own properties. + +Required Properties: +-------------------- + - resets: A phandle and reset specifier pair, one pair for each reset signal + that affects the device, or that the device manages. The phandle + should point to the TI SCI reset controller node, and the reset + specifier should have 2 cell-values. The first cell should contain + the device ID. The second cell should contain the reset mask value + used by system controller. + +Example (AM65x): +---------------- + uart2: serial@02800000 { + compatible = "ti,omap4-uart"; + ... + resets = <&k3_reset 5 1>; + }; diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig index 33c39b7..9c5208b 100644 --- a/drivers/reset/Kconfig +++ b/drivers/reset/Kconfig @@ -49,6 +49,14 @@ config TEGRA186_RESET Enable support for manipulating Tegra's on-SoC reset signals via IPC requests to the BPMP (Boot and Power Management Processor). +config RESET_TI_SCI + bool "TI System Control Interface (TI SCI) reset driver" + depends on DM_RESET && TI_SCI_PROTOCOL + help + This enables the reset driver support over TI System Control Interface + available on some new TI's SoCs. If you wish to use reset resources + managed by the TI System Controller, say Y here. Otherwise, say N. + config RESET_BCM6345 bool "Reset controller driver for BCM6345" depends on DM_RESET && ARCH_BMIPS diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile index ad08be4..abdfa0c 100644 --- a/drivers/reset/Makefile +++ b/drivers/reset/Makefile @@ -9,6 +9,7 @@ obj-$(CONFIG_STI_RESET) += sti-reset.o obj-$(CONFIG_STM32_RESET) += stm32-reset.o obj-$(CONFIG_TEGRA_CAR_RESET) += tegra-car-reset.o obj-$(CONFIG_TEGRA186_RESET) += tegra186-reset.o +obj-$(CONFIG_RESET_TI_SCI) += reset-ti-sci.o obj-$(CONFIG_RESET_BCM6345) += reset-bcm6345.o obj-$(CONFIG_RESET_UNIPHIER) += reset-uniphier.o obj-$(CONFIG_AST2500_RESET) += ast2500-reset.o diff --git a/drivers/reset/reset-ti-sci.c b/drivers/reset/reset-ti-sci.c new file mode 100644 index 0000000..c8a76df --- /dev/null +++ b/drivers/reset/reset-ti-sci.c @@ -0,0 +1,206 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Texas Instruments System Control Interface (TI SCI) reset driver + * + * Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com/ + * Andreas Dannenberg <dannenberg@ti.com> + * + * Loosely based on Linux kernel reset-ti-sci.c... + */ + +#include <common.h> +#include <dm.h> +#include <errno.h> +#include <reset-uclass.h> +#include <linux/soc/ti/ti_sci_protocol.h> + +/** + * struct ti_sci_reset_data - reset controller information structure + * @sci: TI SCI handle used for communication with system controller + */ +struct ti_sci_reset_data { + const struct ti_sci_handle *sci; +}; + +static int ti_sci_reset_probe(struct udevice *dev) +{ + struct ti_sci_reset_data *data = dev_get_priv(dev); + + debug("%s(dev=%p)\n", __func__, dev); + + if (!data) + return -ENOMEM; + + /* Store handle for communication with the system controller */ + data->sci = ti_sci_get_handle(dev); + if (IS_ERR(data->sci)) + return PTR_ERR(data->sci); + + return 0; +} + +static int ti_sci_reset_of_xlate(struct reset_ctl *rst, + struct ofnode_phandle_args *args) +{ + debug("%s(rst=%p, args_count=%d)\n", __func__, rst, args->args_count); + + if (args->args_count != 2) { + debug("Invalid args_count: %d\n", args->args_count); + return -EINVAL; + } + + /* + * On TI SCI-based devices, the reset provider id field is used as a + * device ID, and the data field is used as the associated reset mask. + */ + rst->id = args->args[0]; + rst->data = args->args[1]; + + return 0; +} + +static int ti_sci_reset_request(struct reset_ctl *rst) +{ + debug("%s(rst=%p)\n", __func__, rst); + return 0; +} + +static int ti_sci_reset_free(struct reset_ctl *rst) +{ + debug("%s(rst=%p)\n", __func__, rst); + return 0; +} + +/** + * ti_sci_reset_set() - program a device's reset + * @rst: Handle to a single reset signal + * @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_ctl *rst, bool assert) +{ + struct ti_sci_reset_data *data = dev_get_priv(rst->dev); + const struct ti_sci_handle *sci = data->sci; + const struct ti_sci_dev_ops *dops = &sci->ops.dev_ops; + u32 reset_state; + int ret; + + ret = dops->get_device_resets(sci, rst->id, &reset_state); + if (ret) { + dev_err(rst->dev, "%s: get_device_resets failed (%d)\n", + __func__, ret); + return ret; + } + + if (assert) + reset_state |= rst->data; + else + reset_state &= ~rst->data; + + ret = dops->set_device_resets(sci, rst->id, reset_state); + if (ret) { + dev_err(rst->dev, "%s: set_device_resets failed (%d)\n", + __func__, ret); + return ret; + } + + return 0; +} + +/** + * ti_sci_reset_assert() - assert device reset + * @rst: Handle to a single reset signal + * + * 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_ctl *rst) +{ + debug("%s(rst=%p)\n", __func__, rst); + return ti_sci_reset_set(rst, true); +} + +/** + * ti_sci_reset_deassert() - deassert device reset + * @rst: Handle to a single reset signal + * + * 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_ctl *rst) +{ + debug("%s(rst=%p)\n", __func__, rst); + return ti_sci_reset_set(rst, false); +} + +/** + * ti_sci_reset_status() - check device reset status + * @rst: Handle to a single reset signal + * + * 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 operation .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_ctl *rst) +{ + struct ti_sci_reset_data *data = dev_get_priv(rst->dev); + const struct ti_sci_handle *sci = data->sci; + const struct ti_sci_dev_ops *dops = &sci->ops.dev_ops; + u32 reset_state; + int ret; + + debug("%s(rst=%p)\n", __func__, rst); + + ret = dops->get_device_resets(sci, rst->id, &reset_state); + if (ret) { + dev_err(rst->dev, "%s: get_device_resets failed (%d)\n", + __func__, ret); + return ret; + } + + return reset_state & rst->data; +} + +static const struct udevice_id ti_sci_reset_of_match[] = { + { .compatible = "ti,sci-reset", }, + { /* sentinel */ }, +}; + +static struct reset_ops ti_sci_reset_ops = { + .of_xlate = ti_sci_reset_of_xlate, + .request = ti_sci_reset_request, + .free = ti_sci_reset_free, + .rst_assert = ti_sci_reset_assert, + .rst_deassert = ti_sci_reset_deassert, + .rst_status = ti_sci_reset_status, +}; + +U_BOOT_DRIVER(ti_sci_reset) = { + .name = "ti-sci-reset", + .id = UCLASS_RESET, + .of_match = ti_sci_reset_of_match, + .probe = ti_sci_reset_probe, + .priv_auto_alloc_size = sizeof(struct ti_sci_reset_data), + .ops = &ti_sci_reset_ops, +}; |