Commit f4fcba5c authored by Philipp Tomsich's avatar Philipp Tomsich
Browse files

clk: implement clk_set_defaults()



Linux uses the properties 'assigned-clocks', 'assigned-clock-parents'
and 'assigned-clock-rates' to configure the clock subsystem for use
with various peripheral nodes.

This implements clk_set_defaults() and hooks it up with the general
device probibin in drivers/core/device.c: when a new device is probed,
clk_set_defaults() will be called for it and will process the
properties mentioned above.

Note that this functionality is designed to fail gracefully (i.e. if a
clock-driver does not implement set_parent(), we simply accept this
and ignore the error) as not to break existing board-support.
Signed-off-by: Philipp Tomsich's avatarPhilipp Tomsich <philipp.tomsich@theobroma-systems.com>
Tested-by: default avatarDavid Wu <david.wu@rock-chips.com>

Series-changes: 2
- Fixed David's email address.

Series-version: 2

Cover-letter:
clk: support assigned-clock, assigned-clock-parents, assigned-clock-rates

For various peripherals on Rockchip SoCs (e.g. for the Ethernet GMAC),
the parent-clock needs to be set via the DTS.  This adds the required
plumbing and implements the GMAC case for the RK3399.
END
parent a45f17e8
......@@ -2,6 +2,7 @@
* Copyright (C) 2015 Google, Inc
* Written by Simon Glass <sjg@chromium.org>
* Copyright (c) 2016, NVIDIA CORPORATION.
* Copyright (c) 2018, Theobroma Systems Design und Consulting GmbH
*
* SPDX-License-Identifier: GPL-2.0+
*/
......@@ -10,6 +11,7 @@
#include <clk.h>
#include <clk-uclass.h>
#include <dm.h>
#include <dm/read.h>
#include <dt-structs.h>
#include <errno.h>
......@@ -101,6 +103,122 @@ int clk_get_by_index(struct udevice *dev, int index, struct clk *clk)
{
return clk_get_by_indexed_prop(dev, "clocks", index, clk);
}
static int clk_set_default_parents(struct udevice *dev)
{
struct clk clk, parent_clk;
int index;
int num_parents;
int ret;
num_parents = dev_count_phandle_with_args(dev, "assigned-clock-parents",
"#clock-cells");
if (num_parents < 0) {
debug("%s: could not read assigned-clock-parents for %p\n",
__func__, dev);
return 0;
}
for (index = 0; index < num_parents; index++) {
ret = clk_get_by_indexed_prop(dev, "assigned-clock-parents",
index, &parent_clk);
if (ret) {
debug("%s: could not get parent clock %d for %s\n",
__func__, index, dev_read_name(dev));
return ret;
}
ret = clk_get_by_indexed_prop(dev, "assigned-clocks",
index, &clk);
if (ret) {
debug("%s: could not get assigned clock %d for %s\n",
__func__, index, dev_read_name(dev));
return ret;
}
ret = clk_set_parent(&clk, &parent_clk);
/*
* Not all drivers may support clock-reparenting (as of now).
* Ignore errors due to this.
*/
if (ret == -ENOSYS)
continue;
if (ret) {
debug("%s: failed to reparent clock %d for %s\n",
__func__, index, dev_read_name(dev));
return ret;
}
}
return 0;
}
static int clk_set_default_rates(struct udevice *dev)
{
struct clk clk;
int index;
int num_rates;
int size;
int ret = 0;
u32 *rates = NULL;
size = dev_read_size(dev, "assigned-clock-rates");
if (size < 0)
return 0;
num_rates = size / sizeof(u32);
rates = calloc(num_rates, sizeof(u32));
if (!rates)
return -ENOMEM;
ret = dev_read_u32_array(dev, "assigned-clock-rates", rates, num_rates);
if (ret)
goto fail;
for (index = 0; index < num_rates; index++) {
ret = clk_get_by_indexed_prop(dev, "assigned-clocks",
index, &clk);
if (ret) {
debug("%s: could not get assigned clock %d for %s\n",
__func__, index, dev_read_name(dev));
continue;
}
ret = clk_set_rate(&clk, rates[index]);
if (ret < 0) {
debug("%s: failed to set rate on clock %d for %s\n",
__func__, index, dev_read_name(dev));
break;
}
}
fail:
free(rates);
return ret;
}
int clk_set_defaults(struct udevice *dev)
{
int ret;
/* If this is running pre-reloc state, don't take any action. */
if (!(gd->flags & GD_FLG_RELOC))
return 0;
debug("%s(%s)\n", __func__, dev_read_name(dev));
ret = clk_set_default_parents(dev);
if (ret)
return ret;
ret = clk_set_default_rates(dev);
if (ret < 0)
return ret;
return 0;
}
# endif /* OF_PLATDATA */
int clk_get_by_name(struct udevice *dev, const char *name, struct clk *clk)
......
......@@ -11,6 +11,7 @@
#include <common.h>
#include <asm/io.h>
#include <clk.h>
#include <fdtdec.h>
#include <fdt_support.h>
#include <malloc.h>
......@@ -391,6 +392,11 @@ int device_probe(struct udevice *dev)
goto fail;
}
/* Process 'assigned-{clocks/clock-parents/clock-rates}' properties */
ret = clk_set_defaults(dev);
if (ret)
goto fail;
if (drv->probe) {
ret = drv->probe(dev);
if (ret) {
......
......@@ -133,6 +133,23 @@ static inline int clk_release_all(struct clk *clk, int count)
#endif
#if (CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)) && \
CONFIG_IS_ENABLED(CLK)
/**
* clk_set_defaults - Process 'assigned-{clocks/clock-parents/clock-rates}'
* properties to configure clocks
*
* @dev: A device to process (the ofnode associated with this device
* will be processed).
*/
int clk_set_defaults(struct udevice *dev);
#else
static inline int clk_set_defaults(struct udevice *dev)
{
return 0;
}
#endif
/**
* clk_request - Request a clock by provider-specific ID.
*
......
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment