From 89c1e2da78f82a09685006291ce8bb44f635fa25 Mon Sep 17 00:00:00 2001 From: Stephen Warren Date: Fri, 17 Jun 2016 09:43:58 -0600 Subject: Add a reset driver framework/uclass A reset controller is a hardware module that controls reset signals that affect other hardware modules or chips. This patch defines a standard API that connects reset clients (i.e. the drivers for devices affected by reset signals) to drivers for reset controllers/providers. Initially, DT is the only supported method for connecting the two. The DT binding specification (reset.txt) was taken from Linux kernel v4.5's Documentation/devicetree/bindings/reset/reset.txt. Signed-off-by: Stephen Warren Acked-by: Simon Glass --- include/reset-uclass.h | 81 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 81 insertions(+) create mode 100644 include/reset-uclass.h (limited to 'include/reset-uclass.h') diff --git a/include/reset-uclass.h b/include/reset-uclass.h new file mode 100644 index 0000000..50adeca --- /dev/null +++ b/include/reset-uclass.h @@ -0,0 +1,81 @@ +/* + * Copyright (c) 2016, NVIDIA CORPORATION. + * + * SPDX-License-Identifier: GPL-2.0 + */ + +#ifndef _RESET_UCLASS_H +#define _RESET_UCLASS_H + +/* See reset.h for background documentation. */ + +#include + +struct udevice; + +/** + * struct reset_ops - The functions that a reset controller driver must + * implement. + */ +struct reset_ops { + /** + * of_xlate - Translate a client's device-tree (OF) reset specifier. + * + * The reset core calls this function as the first step in implementing + * a client's reset_get_by_*() call. + * + * If this function pointer is set to NULL, the reset core will use a + * default implementation, which assumes #reset-cells = <1>, and that + * the DT cell contains a simple integer reset signal ID. + * + * At present, the reset API solely supports device-tree. If this + * changes, other xxx_xlate() functions may be added to support those + * other mechanisms. + * + * @reset_ctl: The reset control struct to hold the translation result. + * @args: The reset specifier values from device tree. + * @return 0 if OK, or a negative error code. + */ + int (*of_xlate)(struct reset_ctl *reset_ctl, + struct fdtdec_phandle_args *args); + /** + * request - Request a translated reset control. + * + * The reset core calls this function as the second step in + * implementing a client's reset_get_by_*() call, following a + * successful xxx_xlate() call. + * + * @reset_ctl: The reset control struct to request; this has been + * filled in by a previoux xxx_xlate() function call. + * @return 0 if OK, or a negative error code. + */ + int (*request)(struct reset_ctl *reset_ctl); + /** + * free - Free a previously requested reset control. + * + * This is the implementation of the client reset_free() API. + * + * @reset_ctl: The reset control to free. + * @return 0 if OK, or a negative error code. + */ + int (*free)(struct reset_ctl *reset_ctl); + /** + * rst_assert - Assert a reset signal. + * + * Note: This function is named rst_assert not assert to avoid + * conflicting with global macro assert(). + * + * @reset_ctl: The reset signal to assert. + * @return 0 if OK, or a negative error code. + */ + int (*rst_assert)(struct reset_ctl *reset_ctl); + /** + * rst_deassert - Deassert a reset signal. + * + * @reset_ctl: The reset signal to deassert. + * @return 0 if OK, or a negative error code. + */ + int (*rst_deassert)(struct reset_ctl *reset_ctl); +}; + +#endif -- cgit v1.1