u-boot/drivers/pinctrl/pinctrl-uclass.c
Simon Glass c5acf4a2b3 pinctrl: Add the concept of peripheral IDs
My original pinctrl patch operating using a peripheral ID enum. This was
shared between pinmux and clock and provides an easy way to specify a device
that needs to be controlled, even it is does not (yet) have a driver within
driver model.

Masahiro's new simple pinctrl gets around this by providing a
set_state_simple() pinctrl method. By passing a device to that call the
peripheral ID becomes unnecessary. If the driver needs it, it can calculate
it itself and use it internally.

However this does not solve the problem for peripheral clocks. The 'pure'
solution would be to pass a driver to the clock uclass also. But this
requires that all devices should have a driver, and a struct udevide. Also
a key optimisation of the clock uclass is allowing a peripheral clock to
be set even when there is no device for that clock.

There may be a better way to achive the same goal, but for now it seems
expedient to add in peripheral ID to the pinctrl uclass. Two methods are
added - one to get the peripheral ID and one to select it. The existing
set_state_simple() is effectively the union of these.

Signed-off-by: Simon Glass <sjg@chromium.org>
2015-09-02 21:28:22 -06:00

262 lines
5.9 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/root.h>
#include <dm/uclass.h>
DECLARE_GLOBAL_DATA_PTR;
#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;
const char *name;
int ret;
for (offset = fdt_first_subnode(fdt, offset);
offset > 0;
offset = fdt_next_subnode(fdt, offset)) {
/*
* 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)
{
/* Scan the bus for devices */
return dm_scan_fdt_node(dev, gd->fdt_blob, dev->of_offset, false);
}
#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);
}
/**
* 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;
}
/*
* The pinctrl driver child nodes should be bound so that peripheral
* devices can easily search in parent devices during later DT-parsing.
*/
return pinconfig_post_bind(dev);
}
UCLASS_DRIVER(pinctrl) = {
.id = UCLASS_PINCTRL,
.post_bind = pinctrl_post_bind,
.name = "pinctrl",
};