Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 159 insertions, 0 deletions

diff --git a/drivers/clk/sunxi-ng/ccu_common.c b/drivers/clk/sunxi-ng/ccu_common.c
new file mode 100644
index 000000000..40aac3161
--- /dev/null
+++ b/drivers/clk/sunxi-ng/ccu_common.c
@@ -0,0 +1,159 @@
+/*
+ * Copyright 2016 Maxime Ripard
+ *
+ * Maxime Ripard <maxime.ripard@free-electrons.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; 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.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];
+
+		if (!hw)
+			continue;
+
+		ret = clk_hw_register(NULL, hw);
+		if (ret) {
+			pr_err("Couldn't register clock %d - %s\n",
+			       i, clk_hw_get_name(hw));
+			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;
+}