blob: b986f61f5a7713791d4cbd3abedf56054eab150b [file] [log] [blame]
/*
* OMAP APLL clock support
*
* Copyright (C) 2013 Texas Instruments, Inc.
*
* J Keerthy <j-keerthy@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/module.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/err.h>
#include <linux/string.h>
#include <linux/log2.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/clk/ti.h>
#include <linux/delay.h>
#define APLL_FORCE_LOCK 0x1
#define APLL_AUTO_IDLE 0x2
#define MAX_APLL_WAIT_TRIES 1000000
#undef pr_fmt
#define pr_fmt(fmt) "%s: " fmt, __func__
static int dra7_apll_enable(struct clk_hw *hw)
{
struct clk_hw_omap *clk = to_clk_hw_omap(hw);
int r = 0, i = 0;
struct dpll_data *ad;
const char *clk_name;
u8 state = 1;
u32 v;
ad = clk->dpll_data;
if (!ad)
return -EINVAL;
clk_name = __clk_get_name(clk->hw.clk);
state <<= __ffs(ad->idlest_mask);
/* Check is already locked */
v = ti_clk_ll_ops->clk_readl(ad->idlest_reg);
if ((v & ad->idlest_mask) == state)
return r;
v = ti_clk_ll_ops->clk_readl(ad->control_reg);
v &= ~ad->enable_mask;
v |= APLL_FORCE_LOCK << __ffs(ad->enable_mask);
ti_clk_ll_ops->clk_writel(v, ad->control_reg);
state <<= __ffs(ad->idlest_mask);
while (1) {
v = ti_clk_ll_ops->clk_readl(ad->idlest_reg);
if ((v & ad->idlest_mask) == state)
break;
if (i > MAX_APLL_WAIT_TRIES)
break;
i++;
udelay(1);
}
if (i == MAX_APLL_WAIT_TRIES) {
pr_warn("clock: %s failed transition to '%s'\n",
clk_name, (state) ? "locked" : "bypassed");
} else {
pr_debug("clock: %s transition to '%s' in %d loops\n",
clk_name, (state) ? "locked" : "bypassed", i);
r = 0;
}
return r;
}
static void dra7_apll_disable(struct clk_hw *hw)
{
struct clk_hw_omap *clk = to_clk_hw_omap(hw);
struct dpll_data *ad;
u8 state = 1;
u32 v;
ad = clk->dpll_data;
state <<= __ffs(ad->idlest_mask);
v = ti_clk_ll_ops->clk_readl(ad->control_reg);
v &= ~ad->enable_mask;
v |= APLL_AUTO_IDLE << __ffs(ad->enable_mask);
ti_clk_ll_ops->clk_writel(v, ad->control_reg);
}
static int dra7_apll_is_enabled(struct clk_hw *hw)
{
struct clk_hw_omap *clk = to_clk_hw_omap(hw);
struct dpll_data *ad;
u32 v;
ad = clk->dpll_data;
v = ti_clk_ll_ops->clk_readl(ad->control_reg);
v &= ad->enable_mask;
v >>= __ffs(ad->enable_mask);
return v == APLL_AUTO_IDLE ? 0 : 1;
}
static u8 dra7_init_apll_parent(struct clk_hw *hw)
{
return 0;
}
static const struct clk_ops apll_ck_ops = {
.enable = &dra7_apll_enable,
.disable = &dra7_apll_disable,
.is_enabled = &dra7_apll_is_enabled,
.get_parent = &dra7_init_apll_parent,
};
static void __init omap_clk_register_apll(struct clk_hw *hw,
struct device_node *node)
{
struct clk_hw_omap *clk_hw = to_clk_hw_omap(hw);
struct dpll_data *ad = clk_hw->dpll_data;
struct clk *clk;
ad->clk_ref = of_clk_get(node, 0);
ad->clk_bypass = of_clk_get(node, 1);
if (IS_ERR(ad->clk_ref) || IS_ERR(ad->clk_bypass)) {
pr_debug("clk-ref or clk-bypass for %s not ready, retry\n",
node->name);
if (!ti_clk_retry_init(node, hw, omap_clk_register_apll))
return;
goto cleanup;
}
clk = clk_register(NULL, &clk_hw->hw);
if (!IS_ERR(clk)) {
of_clk_add_provider(node, of_clk_src_simple_get, clk);
kfree(clk_hw->hw.init->parent_names);
kfree(clk_hw->hw.init);
return;
}
cleanup:
kfree(clk_hw->dpll_data);
kfree(clk_hw->hw.init->parent_names);
kfree(clk_hw->hw.init);
kfree(clk_hw);
}
static void __init of_dra7_apll_setup(struct device_node *node)
{
struct dpll_data *ad = NULL;
struct clk_hw_omap *clk_hw = NULL;
struct clk_init_data *init = NULL;
const char **parent_names = NULL;
int i;
ad = kzalloc(sizeof(*ad), GFP_KERNEL);
clk_hw = kzalloc(sizeof(*clk_hw), GFP_KERNEL);
init = kzalloc(sizeof(*init), GFP_KERNEL);
if (!ad || !clk_hw || !init)
goto cleanup;
clk_hw->dpll_data = ad;
clk_hw->hw.init = init;
clk_hw->flags = MEMMAP_ADDRESSING;
init->name = node->name;
init->ops = &apll_ck_ops;
init->num_parents = of_clk_get_parent_count(node);
if (init->num_parents < 1) {
pr_err("dra7 apll %s must have parent(s)\n", node->name);
goto cleanup;
}
parent_names = kzalloc(sizeof(char *) * init->num_parents, GFP_KERNEL);
if (!parent_names)
goto cleanup;
for (i = 0; i < init->num_parents; i++)
parent_names[i] = of_clk_get_parent_name(node, i);
init->parent_names = parent_names;
ad->control_reg = ti_clk_get_reg_addr(node, 0);
ad->idlest_reg = ti_clk_get_reg_addr(node, 1);
if (!ad->control_reg || !ad->idlest_reg)
goto cleanup;
ad->idlest_mask = 0x1;
ad->enable_mask = 0x3;
omap_clk_register_apll(&clk_hw->hw, node);
return;
cleanup:
kfree(parent_names);
kfree(ad);
kfree(clk_hw);
kfree(init);
}
CLK_OF_DECLARE(dra7_apll_clock, "ti,dra7-apll-clock", of_dra7_apll_setup);