Signed-off-by: Lucas Stach <dev@lynxeye.de> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
318 lines
6.4 KiB
C
318 lines
6.4 KiB
C
/*
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* drivers/clk/lookup_clkdev.c
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*
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* Copyright (C) 2008 Russell King.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* Helper for the clk API to assist looking up a struct clk.
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*/
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#include <common.h>
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#include <linux/list.h>
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#include <errno.h>
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#include <linux/err.h>
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#include <linux/string.h>
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#include <linux/clk.h>
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#include <linux/clkdev.h>
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#include <init.h>
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#include <malloc.h>
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#include <of.h>
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#include <stdio.h>
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static LIST_HEAD(clocks);
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#if defined(CONFIG_OFTREE) && defined(CONFIG_COMMON_CLK_OF_PROVIDER)
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struct clk *of_clk_get(struct device_node *np, int index)
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{
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struct of_phandle_args clkspec;
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struct clk *clk;
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int rc;
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if (index < 0)
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return ERR_PTR(-EINVAL);
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rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index,
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&clkspec);
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if (rc)
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return ERR_PTR(rc);
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clk = of_clk_get_from_provider(&clkspec);
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return clk;
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}
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EXPORT_SYMBOL(of_clk_get);
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/**
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* of_clk_get_by_name() - Parse and lookup a clock referenced by a device node
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* @np: pointer to clock consumer node
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* @name: name of consumer's clock input, or NULL for the first clock reference
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*
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* This function parses the clocks and clock-names properties,
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* and uses them to look up the struct clk from the registered list of clock
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* providers.
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*/
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struct clk *of_clk_get_by_name(struct device_node *np, const char *name)
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{
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struct clk *clk = ERR_PTR(-ENOENT);
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/* Walk up the tree of devices looking for a clock that matches */
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while (np) {
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int index = 0;
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/*
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* For named clocks, first look up the name in the
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* "clock-names" property. If it cannot be found, then
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* index will be an error code, and of_clk_get() will fail.
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*/
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if (name)
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index = of_property_match_string(np, "clock-names",
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name);
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clk = of_clk_get(np, index);
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if (!IS_ERR(clk))
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break;
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else if (name && index >= 0) {
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pr_err("ERROR: could not get clock %s:%s(%i)\n",
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np->full_name, name ? name : "", index);
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return clk;
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}
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/*
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* No matching clock found on this node. If the parent node
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* has a "clock-ranges" property, then we can try one of its
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* clocks.
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*/
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np = np->parent;
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if (np && !of_get_property(np, "clock-ranges", NULL))
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break;
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}
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return clk;
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}
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EXPORT_SYMBOL(of_clk_get_by_name);
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#endif
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/*
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* Find the correct struct clk for the device and connection ID.
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* We do slightly fuzzy matching here:
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* An entry with a NULL ID is assumed to be a wildcard.
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* If an entry has a device ID, it must match
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* If an entry has a connection ID, it must match
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* Then we take the most specific entry - with the following
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* order of precedence: dev+con > dev only > con only.
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*/
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static struct clk *clk_find(const char *dev_id, const char *con_id)
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{
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struct clk_lookup *p;
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struct clk *clk = NULL;
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int match, best = 0;
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list_for_each_entry(p, &clocks, node) {
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match = 0;
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if (p->dev_id) {
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if (!dev_id || strcmp(p->dev_id, dev_id))
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continue;
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match += 2;
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}
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if (p->con_id) {
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if (!con_id || strcmp(p->con_id, con_id))
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continue;
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match += 1;
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}
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if (match > best) {
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clk = p->clk;
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if (match != 3)
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best = match;
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else
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break;
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}
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}
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return clk;
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}
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static struct clk *clk_find_physbase(struct device_d *dev, const char *con_id)
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{
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struct clk_lookup *p;
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unsigned long start;
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struct clk *clk = ERR_PTR(-ENOSYS);
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if (!dev || !dev->resource)
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return ERR_PTR(-ENOSYS);
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start = dev->resource[0].start;
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list_for_each_entry(p, &clocks, node) {
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if (p->physbase == ~0)
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continue;
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if (p->physbase != start)
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continue;
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if (p->con_id) {
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if (!con_id || strcmp(p->con_id, con_id))
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continue;
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return p->clk;
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}
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clk = p->clk;
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}
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return clk;
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}
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struct clk *clk_get_sys(const char *dev_id, const char *con_id)
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{
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struct clk *clk;
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clk = clk_find(dev_id, con_id);
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return clk ? clk : ERR_PTR(-ENOENT);
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}
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EXPORT_SYMBOL(clk_get_sys);
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struct clk *clk_get(struct device_d *dev, const char *con_id)
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{
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const char *dev_id = dev ? dev_name(dev) : NULL;
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struct clk *clk;
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clk = clk_find_physbase(dev, con_id);
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if (!IS_ERR(clk))
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return clk;
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if (dev) {
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clk = of_clk_get_by_name(dev->device_node, con_id);
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if (!IS_ERR(clk))
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return clk;
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}
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return clk_get_sys(dev_id, con_id);
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}
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EXPORT_SYMBOL(clk_get);
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void clk_put(struct clk *clk)
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{
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}
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EXPORT_SYMBOL(clk_put);
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void clkdev_add(struct clk_lookup *cl)
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{
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if (cl->dev_id)
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cl->physbase = ~0;
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list_add_tail(&cl->node, &clocks);
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}
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EXPORT_SYMBOL(clkdev_add);
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void __init clkdev_add_table(struct clk_lookup *cl, size_t num)
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{
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while (num--) {
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if (cl->dev_id)
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cl->physbase = ~0;
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list_add_tail(&cl->node, &clocks);
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cl++;
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}
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}
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#define MAX_DEV_ID 20
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#define MAX_CON_ID 16
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struct clk_lookup_alloc {
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struct clk_lookup cl;
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char dev_id[MAX_DEV_ID];
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char con_id[MAX_CON_ID];
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};
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struct clk_lookup *clkdev_alloc(struct clk *clk, const char *con_id,
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const char *dev_fmt, ...)
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{
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struct clk_lookup_alloc *cla;
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cla = kzalloc(sizeof(*cla), GFP_KERNEL);
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if (!cla)
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return NULL;
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cla->cl.physbase = ~0;
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cla->cl.clk = clk;
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if (con_id) {
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strlcpy(cla->con_id, con_id, sizeof(cla->con_id));
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cla->cl.con_id = cla->con_id;
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}
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if (dev_fmt) {
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va_list ap;
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va_start(ap, dev_fmt);
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vscnprintf(cla->dev_id, sizeof(cla->dev_id), dev_fmt, ap);
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cla->cl.dev_id = cla->dev_id;
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va_end(ap);
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}
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return &cla->cl;
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}
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EXPORT_SYMBOL(clkdev_alloc);
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int clk_register_clkdev(struct clk *clk, const char *con_id,
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const char *dev_fmt, ...)
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{
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struct clk_lookup *cl;
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va_list ap;
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if (IS_ERR(clk))
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return PTR_ERR(clk);
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va_start(ap, dev_fmt);
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cl = clkdev_alloc(clk, con_id, dev_fmt, ap);
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va_end(ap);
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if (!cl)
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return -ENOMEM;
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clkdev_add(cl);
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return 0;
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}
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int clk_add_alias(const char *alias, const char *alias_dev_name, char *id,
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struct device_d *dev)
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{
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struct clk *r = clk_get(dev, id);
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struct clk_lookup *l;
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if (IS_ERR(r))
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return PTR_ERR(r);
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l = clkdev_alloc(r, alias, alias_dev_name);
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clk_put(r);
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if (!l)
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return -ENODEV;
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clkdev_add(l);
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return 0;
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}
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EXPORT_SYMBOL(clk_add_alias);
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/*
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* clkdev_drop - remove a clock dynamically allocated
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*/
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void clkdev_drop(struct clk_lookup *cl)
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{
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list_del(&cl->node);
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kfree(cl);
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}
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EXPORT_SYMBOL(clkdev_drop);
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int clkdev_add_physbase(struct clk *clk, unsigned long base, const char *id)
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{
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struct clk_lookup *cl;
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cl = xzalloc(sizeof(*cl));
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cl->clk = clk;
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cl->con_id = id;
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cl->physbase = base;
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clkdev_add(cl);
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return 0;
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}
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EXPORT_SYMBOL(clkdev_add_physbase);
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