Hi Stephen,
On Thu, Aug 25, 2011 at 05:43:41PM -0600, Stephen Warren wrote:
> From: Jamie Iles <jamie@xxxxxxxxxxxxx>
>
> 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 <jamie@xxxxxxxxxxxxx>
> [swarren: Added support for pins property, added parse() callback, use
> dev_err instead of pr_err, related minor changes]
> Signed-off-by: Stephen Warren <swarren@xxxxxxxxxx>
> ---
> 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;
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);
For format strings I believe it's preferred to keep it on one long line
so it can at least be grepped for.
> + 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.
The kerneldoc is out of date here.
> + */
> +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.
and here.
> + */
> +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
>
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