From: Jamie Iles <[email protected]> This patch adds a helper function of_pinmux_parse() that can be used to extract common pinmux configuration to avoid each platform implementing a parsing loop. Platforms supply the node containing the pinmux definitions and a platform specific callback for configuring a pingroup.
Signed-off-by: Jamie Iles <[email protected]> [swarren: Added support for pins property, added parse() callback, use dev_err instead of pr_err, related minor changes] Signed-off-by: Stephen Warren <[email protected]> --- drivers/of/Kconfig | 5 ++ drivers/of/Makefile | 1 + drivers/of/of_pinmux.c | 109 +++++++++++++++++++++++++++++++++++++++++++++ include/linux/of_pinmux.h | 74 ++++++++++++++++++++++++++++++ 4 files changed, 189 insertions(+), 0 deletions(-) create mode 100644 drivers/of/of_pinmux.c create mode 100644 include/linux/of_pinmux.h diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig index cac63c9..71a19a3 100644 --- a/drivers/of/Kconfig +++ b/drivers/of/Kconfig @@ -81,4 +81,9 @@ config OF_PCI_IRQ help OpenFirmware PCI IRQ routing helpers +config OF_PINMUX + def_bool y + help + OpenFirmware pin multiplexing helpers + endmenu # OF diff --git a/drivers/of/Makefile b/drivers/of/Makefile index dccb117..0666ff3 100644 --- a/drivers/of/Makefile +++ b/drivers/of/Makefile @@ -11,3 +11,4 @@ obj-$(CONFIG_OF_SPI) += of_spi.o obj-$(CONFIG_OF_MDIO) += of_mdio.o obj-$(CONFIG_OF_PCI) += of_pci.o obj-$(CONFIG_OF_PCI_IRQ) += of_pci_irq.o +obj-$(CONFIG_OF_PINMUX) += of_pinmux.o diff --git a/drivers/of/of_pinmux.c b/drivers/of/of_pinmux.c new file mode 100644 index 0000000..8050b8b --- /dev/null +++ b/drivers/of/of_pinmux.c @@ -0,0 +1,109 @@ +/* + * Copyright (c) 2011 Picochip Ltd., Jamie Iles + * Copyright (c) 2011 NVIDIA, Inc. + * + * Generic pinmux bindings for device tree. + * + * 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. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ +#include <linux/device.h> +#include <linux/errno.h> +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/of.h> +#include <linux/of_iter_prop.h> +#include <linux/of_pinmux.h> + +/** + * of_pinmux_parse - configure a set of pinmux groups for a pinmux controller + * + * @controller: the controller to configure the pinmux entries for. This + * defines the controller device node and the callback for configuring + * the pingroups. + * + * This helper loops over all of the child nodes of a pinmux controller and + * collects the configuration for each pinmux group. A pinmux group is + * defined as one or more pins that are configured to a common function. This + * handles common properties that many platforms may implement, but for + * platform specific properties these may be handled in the configure + * callback. + */ +int of_pinmux_parse(const struct of_pinmux_ctrl *ctrl, + struct of_pinmux_cfg *cfg) +{ + struct device_node *np; + + if (!ctrl || !ctrl->dev || !ctrl->node || !ctrl->configure) + return -EINVAL; + + for_each_child_of_node(ctrl->node, np) { + int ret; + bool hadpins = 0; + struct of_iter_string_prop iter; + + cfg->node = np; + + ret = of_property_read_string(np, "function", + &cfg->function); + if (ret < 0) { + dev_err(ctrl->dev, "no function for node %s\n", + np->name); + continue; + } + + cfg->flags &= 0; + + if (of_find_property(np, "pull-up", NULL)) + cfg->flags |= OF_PINMUX_PULL_UP; + if (of_find_property(np, "pull-down", NULL)) + cfg->flags |= OF_PINMUX_PULL_DOWN; + + if ((cfg->flags & OF_PINMUX_PULL_MASK) == + OF_PINMUX_PULL_MASK) { + dev_warn(ctrl->dev, "node %s has both " + "pull-up and pull-down properties - " + "defaulting to no pull\n", + np->name); + cfg->flags &= ~OF_PINMUX_PULL_MASK; + } + + if (of_find_property(np, "tristate", NULL)) + cfg->flags |= OF_PINMUX_TRISTATE; + + if (ctrl->parse && ctrl->parse(ctrl, cfg)) { + dev_warn(ctrl->dev, + "failed to parse node %s\n", + np->name); + continue; + } + + for_each_string_property_value(iter, np, "pins") { + hadpins = 1; + + cfg->pin = iter.value; + + dev_dbg(ctrl->dev, + "configure pin %s func=%s flags=0x%lx\n", + cfg->pin, cfg->function, cfg->flags); + if (ctrl->configure(ctrl, cfg)) + dev_warn(ctrl->dev, + "failed to configure pin %s\n", + cfg->pin); + } + + if (!hadpins) + dev_warn(ctrl->dev, "no pins for node %s\n", + np->name); + } + + return 0; +} +EXPORT_SYMBOL_GPL(of_pinmux_parse); diff --git a/include/linux/of_pinmux.h b/include/linux/of_pinmux.h new file mode 100644 index 0000000..7ccddcf --- /dev/null +++ b/include/linux/of_pinmux.h @@ -0,0 +1,74 @@ +/* + * Copyright (c) 2011 Picochip Ltd., Jamie Iles + * Copyright (c) 2011 NVIDIA, Inc. + * + * Generic pinmux bindings for device tree. + * + * 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. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ +#ifndef __OF_PINMUX_H__ +#define __OF_PINMUX_H__ + +struct device_node; + +#define OF_PINMUX_PULL_UP (1 << 0) +#define OF_PINMUX_PULL_DOWN (1 << 1) +#define OF_PINMUX_TRISTATE (1 << 2) + +#define OF_PINMUX_PULL_MASK (OF_PINMUX_PULL_UP | OF_PINMUX_PULL_DOWN) + +/** + * struct of_pinmux_cfg - configuration state for a single pinmux entry. + * + * @function: the name of the function that the pinmux entry should be + * configured to. + * @pin: the device_node of the pinmux entry that should be configured. + * Platform specific properties that aren't in the generic binding may be + * obtained from this device node. + * @flags: flags for common pinmux options such as pull and tristate. + */ +struct of_pinmux_cfg { + struct device_node *node; + const char *pin; + const char *function; + unsigned long flags; +}; + +/** + * struct of_pinmux_ctrl - platform specific pinmux control state. + * + * @pinmux: the pinmux device node. All child nodes are required to be the + * pinmux entry definitions. Depending on the platform, this may either be + * a single pin or a group of pins where they can be set to a common + * function. + * @configure: platform specific callback to configure the pinmux entry. + */ +struct of_pinmux_ctrl { + struct device *dev; + struct device_node *node; + int (*parse)(const struct of_pinmux_ctrl *ctrl, + struct of_pinmux_cfg *cfg); + int (*configure)(const struct of_pinmux_ctrl *ctrl, + const struct of_pinmux_cfg *cfg); +}; + +#ifdef CONFIG_OF +extern int of_pinmux_parse(const struct of_pinmux_ctrl *ctrl, + struct of_pinmux_cfg *cfg); +#else +static inline int of_pinmux_parse(const struct of_pinmux_ctrl *ctrl, + struct of_pinmux_cfg *cfg) +{ + return -ENOSYS; +} +#endif /* CONFIG_OF */ + +#endif /* __OF_PINMUX_H__ */ -- 1.7.0.4 _______________________________________________ devicetree-discuss mailing list [email protected] https://lists.ozlabs.org/listinfo/devicetree-discuss
