Orange Pi5 kernel

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright 2016 Maxime Ripard
 *
 * Maxime Ripard <maxime.ripard@free-electrons.com>
 */
 
#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/iopoll.h>
#include <linux/slab.h>
 
#include "ccu_common.h"
#include "ccu_gate.h"
#include "ccu_reset.h"
 
static DEFINE_SPINLOCK(ccu_lock);
 
void ccu_helper_wait_for_lock(struct ccu_common *common, u32 lock)
{
<------>void __iomem *addr;
<------>u32 reg;
 
<------>if (!lock)
<------><------>return;
 
<------>if (common->features & CCU_FEATURE_LOCK_REG)
<------><------>addr = common->base + common->lock_reg;
<------>else
<------><------>addr = common->base + common->reg;
 
<------>WARN_ON(readl_relaxed_poll_timeout(addr, reg, reg & lock, 100, 70000));
}
 
/*
 * This clock notifier is called when the frequency of a PLL clock is
 * changed. In common PLL designs, changes to the dividers take effect
 * almost immediately, while changes to the multipliers (implemented
 * as dividers in the feedback loop) take a few cycles to work into
 * the feedback loop for the PLL to stablize.
 *
 * Sometimes when the PLL clock rate is changed, the decrease in the
 * divider is too much for the decrease in the multiplier to catch up.
 * The PLL clock rate will spike, and in some cases, might lock up
 * completely.
 *
 * This notifier callback will gate and then ungate the clock,
 * effectively resetting it, so it proceeds to work. Care must be
 * taken to reparent consumers to other temporary clocks during the
 * rate change, and that this notifier callback must be the first
 * to be registered.
 */
static int ccu_pll_notifier_cb(struct notifier_block *nb,
<------><------><------>       unsigned long event, void *data)
{
<------>struct ccu_pll_nb *pll = to_ccu_pll_nb(nb);
<------>int ret = 0;
 
<------>if (event != POST_RATE_CHANGE)
<------><------>goto out;
 
<------>ccu_gate_helper_disable(pll->common, pll->enable);
 
<------>ret = ccu_gate_helper_enable(pll->common, pll->enable);
<------>if (ret)
<------><------>goto out;
 
<------>ccu_helper_wait_for_lock(pll->common, pll->lock);
 
out:
<------>return notifier_from_errno(ret);
}
 
int ccu_pll_notifier_register(struct ccu_pll_nb *pll_nb)
{
<------>pll_nb->clk_nb.notifier_call = ccu_pll_notifier_cb;
 
<------>return clk_notifier_register(pll_nb->common->hw.clk,
<------><------><------><------>     &pll_nb->clk_nb);
}
 
int sunxi_ccu_probe(struct device_node *node, void __iomem *reg,
<------><------>    const struct sunxi_ccu_desc *desc)
{
<------>struct ccu_reset *reset;
<------>int i, ret;
 
<------>for (i = 0; i < desc->num_ccu_clks; i++) {
<------><------>struct ccu_common *cclk = desc->ccu_clks[i];
 
<------><------>if (!cclk)
<------><------><------>continue;
 
<------><------>cclk->base = reg;
<------><------>cclk->lock = &ccu_lock;
<------>}
 
<------>for (i = 0; i < desc->hw_clks->num ; i++) {
<------><------>struct clk_hw *hw = desc->hw_clks->hws[i];
<------><------>const char *name;
 
<------><------>if (!hw)
<------><------><------>continue;
 
<------><------>name = hw->init->name;
<------><------>ret = of_clk_hw_register(node, hw);
<------><------>if (ret) {
<------><------><------>pr_err("Couldn't register clock %d - %s\n", i, name);
<------><------><------>goto err_clk_unreg;
<------><------>}
<------>}
 
<------>ret = of_clk_add_hw_provider(node, of_clk_hw_onecell_get,
<------><------><------><------>     desc->hw_clks);
<------>if (ret)
<------><------>goto err_clk_unreg;
 
<------>reset = kzalloc(sizeof(*reset), GFP_KERNEL);
<------>if (!reset) {
<------><------>ret = -ENOMEM;
<------><------>goto err_alloc_reset;
<------>}
 
<------>reset->rcdev.of_node = node;
<------>reset->rcdev.ops = &ccu_reset_ops;
<------>reset->rcdev.owner = THIS_MODULE;
<------>reset->rcdev.nr_resets = desc->num_resets;
<------>reset->base = reg;
<------>reset->lock = &ccu_lock;
<------>reset->reset_map = desc->resets;
 
<------>ret = reset_controller_register(&reset->rcdev);
<------>if (ret)
<------><------>goto err_of_clk_unreg;
 
<------>return 0;
 
err_of_clk_unreg:
<------>kfree(reset);
err_alloc_reset:
<------>of_clk_del_provider(node);
err_clk_unreg:
<------>while (--i >= 0) {
<------><------>struct clk_hw *hw = desc->hw_clks->hws[i];
 
<------><------>if (!hw)
<------><------><------>continue;
<------><------>clk_hw_unregister(hw);
<------>}
<------>return ret;
}