u-boot/drivers/pinctrl/pinctrl-uclass.c
Simon Glass 77eaa19e73 dm: pinctrl: Add a way for a GPIO driver to obtain a pin function
GPIO drivers want to be able to show if a pin is enabled for input, output,
or is being used by another function. Some drivers can easily find this
and the code is included in the driver. For some SoCs this is more complex.
Conceptually this should be handled by pinctrl rather than GPIO. Most
pinctrl drivers will have this feature anyway.

Add a method by which a GPIO driver can obtain the pin mux value given a
GPIO reference. This avoids repeating the code in two places.

Signed-off-by: Simon Glass <sjg@chromium.org>
2016-01-21 20:42:35 -07:00

291 lines
6.6 KiB
C

/*
* Copyright (C) 2015 Masahiro Yamada <yamada.masahiro@socionext.com>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <libfdt.h>
#include <linux/err.h>
#include <linux/list.h>
#include <dm/device.h>
#include <dm/lists.h>
#include <dm/pinctrl.h>
#include <dm/uclass.h>
DECLARE_GLOBAL_DATA_PTR;
int pinctrl_decode_pin_config(const void *blob, int node)
{
int flags = 0;
if (fdtdec_get_bool(blob, node, "bias-pull-up"))
flags |= 1 << PIN_CONFIG_BIAS_PULL_UP;
else if (fdtdec_get_bool(blob, node, "bias-pull-down"))
flags |= 1 << PIN_CONFIG_BIAS_PULL_DOWN;
return flags;
}
#if CONFIG_IS_ENABLED(PINCTRL_FULL)
/**
* pinctrl_config_one() - apply pinctrl settings for a single node
*
* @config: pin configuration node
* @return: 0 on success, or negative error code on failure
*/
static int pinctrl_config_one(struct udevice *config)
{
struct udevice *pctldev;
const struct pinctrl_ops *ops;
pctldev = config;
for (;;) {
pctldev = dev_get_parent(pctldev);
if (!pctldev) {
dev_err(config, "could not find pctldev\n");
return -EINVAL;
}
if (pctldev->uclass->uc_drv->id == UCLASS_PINCTRL)
break;
}
ops = pinctrl_get_ops(pctldev);
return ops->set_state(pctldev, config);
}
/**
* pinctrl_select_state_full() - full implementation of pinctrl_select_state
*
* @dev: peripheral device
* @statename: state name, like "default"
* @return: 0 on success, or negative error code on failure
*/
static int pinctrl_select_state_full(struct udevice *dev, const char *statename)
{
const void *fdt = gd->fdt_blob;
int node = dev->of_offset;
char propname[32]; /* long enough */
const fdt32_t *list;
uint32_t phandle;
int config_node;
struct udevice *config;
int state, size, i, ret;
state = fdt_find_string(fdt, node, "pinctrl-names", statename);
if (state < 0) {
char *end;
/*
* If statename is not found in "pinctrl-names",
* assume statename is just the integer state ID.
*/
state = simple_strtoul(statename, &end, 10);
if (*end)
return -EINVAL;
}
snprintf(propname, sizeof(propname), "pinctrl-%d", state);
list = fdt_getprop(fdt, node, propname, &size);
if (!list)
return -EINVAL;
size /= sizeof(*list);
for (i = 0; i < size; i++) {
phandle = fdt32_to_cpu(*list++);
config_node = fdt_node_offset_by_phandle(fdt, phandle);
if (config_node < 0) {
dev_err(dev, "prop %s index %d invalid phandle\n",
propname, i);
return -EINVAL;
}
ret = uclass_get_device_by_of_offset(UCLASS_PINCONFIG,
config_node, &config);
if (ret)
return ret;
ret = pinctrl_config_one(config);
if (ret)
return ret;
}
return 0;
}
/**
* pinconfig_post-bind() - post binding for PINCONFIG uclass
* Recursively bind its children as pinconfig devices.
*
* @dev: pinconfig device
* @return: 0 on success, or negative error code on failure
*/
static int pinconfig_post_bind(struct udevice *dev)
{
const void *fdt = gd->fdt_blob;
int offset = dev->of_offset;
bool pre_reloc_only = !(gd->flags & GD_FLG_RELOC);
const char *name;
int ret;
for (offset = fdt_first_subnode(fdt, offset);
offset > 0;
offset = fdt_next_subnode(fdt, offset)) {
if (pre_reloc_only &&
!fdt_getprop(fdt, offset, "u-boot,dm-pre-reloc", NULL))
continue;
/*
* If this node has "compatible" property, this is not
* a pin configuration node, but a normal device. skip.
*/
fdt_get_property(fdt, offset, "compatible", &ret);
if (ret >= 0)
continue;
if (ret != -FDT_ERR_NOTFOUND)
return ret;
name = fdt_get_name(fdt, offset, NULL);
if (!name)
return -EINVAL;
ret = device_bind_driver_to_node(dev, "pinconfig", name,
offset, NULL);
if (ret)
return ret;
}
return 0;
}
UCLASS_DRIVER(pinconfig) = {
.id = UCLASS_PINCONFIG,
.post_bind = pinconfig_post_bind,
.name = "pinconfig",
};
U_BOOT_DRIVER(pinconfig_generic) = {
.name = "pinconfig",
.id = UCLASS_PINCONFIG,
};
#else
static int pinctrl_select_state_full(struct udevice *dev, const char *statename)
{
return -ENODEV;
}
static int pinconfig_post_bind(struct udevice *dev)
{
return 0;
}
#endif
/**
* pinctrl_select_state_simple() - simple implementation of pinctrl_select_state
*
* @dev: peripheral device
* @return: 0 on success, or negative error code on failure
*/
static int pinctrl_select_state_simple(struct udevice *dev)
{
struct udevice *pctldev;
struct pinctrl_ops *ops;
int ret;
/*
* For simplicity, assume the first device of PINCTRL uclass
* is the correct one. This is most likely OK as there is
* usually only one pinctrl device on the system.
*/
ret = uclass_get_device(UCLASS_PINCTRL, 0, &pctldev);
if (ret)
return ret;
ops = pinctrl_get_ops(pctldev);
if (!ops->set_state_simple) {
dev_dbg(dev, "set_state_simple op missing\n");
return -ENOSYS;
}
return ops->set_state_simple(pctldev, dev);
}
int pinctrl_select_state(struct udevice *dev, const char *statename)
{
/*
* Try full-implemented pinctrl first.
* If it fails or is not implemented, try simple one.
*/
if (pinctrl_select_state_full(dev, statename))
return pinctrl_select_state_simple(dev);
return 0;
}
int pinctrl_request(struct udevice *dev, int func, int flags)
{
struct pinctrl_ops *ops = pinctrl_get_ops(dev);
if (!ops->request)
return -ENOSYS;
return ops->request(dev, func, flags);
}
int pinctrl_request_noflags(struct udevice *dev, int func)
{
return pinctrl_request(dev, func, 0);
}
int pinctrl_get_periph_id(struct udevice *dev, struct udevice *periph)
{
struct pinctrl_ops *ops = pinctrl_get_ops(dev);
if (!ops->get_periph_id)
return -ENOSYS;
return ops->get_periph_id(dev, periph);
}
int pinctrl_get_gpio_mux(struct udevice *dev, int banknum, int index)
{
struct pinctrl_ops *ops = pinctrl_get_ops(dev);
if (!ops->get_gpio_mux)
return -ENOSYS;
return ops->get_gpio_mux(dev, banknum, index);
}
/**
* pinconfig_post-bind() - post binding for PINCTRL uclass
* Recursively bind child nodes as pinconfig devices in case of full pinctrl.
*
* @dev: pinctrl device
* @return: 0 on success, or negative error code on failure
*/
static int pinctrl_post_bind(struct udevice *dev)
{
const struct pinctrl_ops *ops = pinctrl_get_ops(dev);
if (!ops) {
dev_dbg(dev, "ops is not set. Do not bind.\n");
return -EINVAL;
}
/*
* If set_state callback is set, we assume this pinctrl driver is the
* full implementation. In this case, its child nodes should be bound
* so that peripheral devices can easily search in parent devices
* during later DT-parsing.
*/
if (ops->set_state)
return pinconfig_post_bind(dev);
return 0;
}
UCLASS_DRIVER(pinctrl) = {
.id = UCLASS_PINCTRL,
.post_bind = pinctrl_post_bind,
.name = "pinctrl",
};