linux/drivers/clk/ti/clk.c
Tero Kristo c08ee14cc6 clk: ti: change clock init to use generic of_clk_init
Previously, the TI clock driver initialized all the clocks hierarchically
under each separate clock provider node. Now, each clock that requires
IO access will instead check their parent node to find out which IO range
to use.

This patch allows the TI clock driver to use a few new features provided
by the generic of_clk_init, and also allows registration of clock nodes
outside the clock hierarchy (for example, any external clocks.)

Signed-off-by: Tero Kristo <t-kristo@ti.com>
Cc: Mike Turquette <mturquette@linaro.org>
Cc: Paul Walmsley <paul@pwsan.com>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Ujfalusi <peter.ujfalusi@ti.com>
Cc: Jyri Sarha <jsarha@ti.com>
Cc: Stefan Assmann <sassmann@kpanic.de>
Acked-by: Tony Lindgren <tony@atomide.com>
2014-09-29 11:51:13 +03:00

186 lines
4.7 KiB
C

/*
* TI clock support
*
* Copyright (C) 2013 Texas Instruments, Inc.
*
* Tero Kristo <t-kristo@ti.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed "as is" WITHOUT ANY WARRANTY of any
* kind, whether express or implied; without even the implied warranty
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/clk-provider.h>
#include <linux/clkdev.h>
#include <linux/clk/ti.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/list.h>
#undef pr_fmt
#define pr_fmt(fmt) "%s: " fmt, __func__
struct ti_clk_ll_ops *ti_clk_ll_ops;
static struct device_node *clocks_node_ptr[CLK_MAX_MEMMAPS];
/**
* ti_dt_clocks_register - register DT alias clocks during boot
* @oclks: list of clocks to register
*
* Register alias or non-standard DT clock entries during boot. By
* default, DT clocks are found based on their node name. If any
* additional con-id / dev-id -> clock mapping is required, use this
* function to list these.
*/
void __init ti_dt_clocks_register(struct ti_dt_clk oclks[])
{
struct ti_dt_clk *c;
struct device_node *node;
struct clk *clk;
struct of_phandle_args clkspec;
for (c = oclks; c->node_name != NULL; c++) {
node = of_find_node_by_name(NULL, c->node_name);
clkspec.np = node;
clk = of_clk_get_from_provider(&clkspec);
if (!IS_ERR(clk)) {
c->lk.clk = clk;
clkdev_add(&c->lk);
} else {
pr_warn("failed to lookup clock node %s\n",
c->node_name);
}
}
}
struct clk_init_item {
struct device_node *node;
struct clk_hw *hw;
ti_of_clk_init_cb_t func;
struct list_head link;
};
static LIST_HEAD(retry_list);
/**
* ti_clk_retry_init - retries a failed clock init at later phase
* @node: device not for the clock
* @hw: partially initialized clk_hw struct for the clock
* @func: init function to be called for the clock
*
* Adds a failed clock init to the retry list. The retry list is parsed
* once all the other clocks have been initialized.
*/
int __init ti_clk_retry_init(struct device_node *node, struct clk_hw *hw,
ti_of_clk_init_cb_t func)
{
struct clk_init_item *retry;
pr_debug("%s: adding to retry list...\n", node->name);
retry = kzalloc(sizeof(*retry), GFP_KERNEL);
if (!retry)
return -ENOMEM;
retry->node = node;
retry->func = func;
retry->hw = hw;
list_add(&retry->link, &retry_list);
return 0;
}
/**
* ti_clk_get_reg_addr - get register address for a clock register
* @node: device node for the clock
* @index: register index from the clock node
*
* Builds clock register address from device tree information. This
* is a struct of type clk_omap_reg.
*/
void __iomem *ti_clk_get_reg_addr(struct device_node *node, int index)
{
struct clk_omap_reg *reg;
u32 val;
u32 tmp;
int i;
reg = (struct clk_omap_reg *)&tmp;
for (i = 0; i < CLK_MAX_MEMMAPS; i++) {
if (clocks_node_ptr[i] == node->parent)
break;
}
if (i == CLK_MAX_MEMMAPS) {
pr_err("clk-provider not found for %s!\n", node->name);
return NULL;
}
reg->index = i;
if (of_property_read_u32_index(node, "reg", index, &val)) {
pr_err("%s must have reg[%d]!\n", node->name, index);
return NULL;
}
reg->offset = val;
return (void __iomem *)tmp;
}
/**
* ti_dt_clk_init_provider - init master clock provider
* @parent: master node
* @index: internal index for clk_reg_ops
*
* Initializes a master clock IP block. This basically sets up the
* mapping from clocks node to the memory map index. All the clocks
* are then initialized through the common of_clk_init call, and the
* clocks will access their memory maps based on the node layout.
*/
void ti_dt_clk_init_provider(struct device_node *parent, int index)
{
struct device_node *clocks;
/* get clocks for this parent */
clocks = of_get_child_by_name(parent, "clocks");
if (!clocks) {
pr_err("%s missing 'clocks' child node.\n", parent->name);
return;
}
/* add clocks node info */
clocks_node_ptr[index] = clocks;
}
/**
* ti_dt_clk_init_retry_clks - init clocks from the retry list
*
* Initializes any clocks that have failed to initialize before,
* reasons being missing parent node(s) during earlier init. This
* typically happens only for DPLLs which need to have both of their
* parent clocks ready during init.
*/
void ti_dt_clk_init_retry_clks(void)
{
struct clk_init_item *retry;
struct clk_init_item *tmp;
int retries = 5;
while (!list_empty(&retry_list) && retries) {
list_for_each_entry_safe(retry, tmp, &retry_list, link) {
pr_debug("retry-init: %s\n", retry->node->name);
retry->func(retry->hw, retry->node);
list_del(&retry->link);
kfree(retry);
}
retries--;
}
}