1 files changed, 311 insertions, 0 deletions
diff --git a/drivers/media/platform/microchip/microchip-isc-clk.c b/drivers/media/platform/microchip/microchip-isc-clk.c
new file mode 100644
index 000000000000..24358d804e75
--- /dev/null
+++ b/drivers/media/platform/microchip/microchip-isc-clk.c
@@ -0,0 +1,311 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Microchip Image Sensor Controller (ISC) common clock driver setup
+ *
+ * Copyright (C) 2016 Microchip Technology, Inc.
+ *
+ * Author: Songjun Wu
+ * Author: Eugen Hristev <[email protected]>
+ *
+ */
+#include <linux/clk.h>
+#include <linux/clkdev.h>
+#include <linux/clk-provider.h>
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+
+#include "microchip-isc-regs.h"
+#include "microchip-isc.h"
+
+static int isc_wait_clk_stable(struct clk_hw *hw)
+{
+	struct isc_clk *isc_clk = to_isc_clk(hw);
+	struct regmap *regmap = isc_clk->regmap;
+	unsigned long timeout = jiffies + usecs_to_jiffies(1000);
+	unsigned int status;
+
+	while (time_before(jiffies, timeout)) {
+		regmap_read(regmap, ISC_CLKSR, &status);
+		if (!(status & ISC_CLKSR_SIP))
+			return 0;
+
+		usleep_range(10, 250);
+	}
+
+	return -ETIMEDOUT;
+}
+
+static int isc_clk_prepare(struct clk_hw *hw)
+{
+	struct isc_clk *isc_clk = to_isc_clk(hw);
+	int ret;
+
+	ret = pm_runtime_resume_and_get(isc_clk->dev);
+	if (ret < 0)
+		return ret;
+
+	return isc_wait_clk_stable(hw);
+}
+
+static void isc_clk_unprepare(struct clk_hw *hw)
+{
+	struct isc_clk *isc_clk = to_isc_clk(hw);
+
+	isc_wait_clk_stable(hw);
+
+	pm_runtime_put_sync(isc_clk->dev);
+}
+
+static int isc_clk_enable(struct clk_hw *hw)
+{
+	struct isc_clk *isc_clk = to_isc_clk(hw);
+	u32 id = isc_clk->id;
+	struct regmap *regmap = isc_clk->regmap;
+	unsigned long flags;
+	unsigned int status;
+
+	dev_dbg(isc_clk->dev, "ISC CLK: %s, id = %d, div = %d, parent id = %d\n",
+		__func__, id, isc_clk->div, isc_clk->parent_id);
+
+	spin_lock_irqsave(&isc_clk->lock, flags);
+	regmap_update_bits(regmap, ISC_CLKCFG,
+			   ISC_CLKCFG_DIV_MASK(id) | ISC_CLKCFG_SEL_MASK(id),
+			   (isc_clk->div << ISC_CLKCFG_DIV_SHIFT(id)) |
+			   (isc_clk->parent_id << ISC_CLKCFG_SEL_SHIFT(id)));
+
+	regmap_write(regmap, ISC_CLKEN, ISC_CLK(id));
+	spin_unlock_irqrestore(&isc_clk->lock, flags);
+
+	regmap_read(regmap, ISC_CLKSR, &status);
+	if (status & ISC_CLK(id))
+		return 0;
+	else
+		return -EINVAL;
+}
+
+static void isc_clk_disable(struct clk_hw *hw)
+{
+	struct isc_clk *isc_clk = to_isc_clk(hw);
+	u32 id = isc_clk->id;
+	unsigned long flags;
+
+	spin_lock_irqsave(&isc_clk->lock, flags);
+	regmap_write(isc_clk->regmap, ISC_CLKDIS, ISC_CLK(id));
+	spin_unlock_irqrestore(&isc_clk->lock, flags);
+}
+
+static int isc_clk_is_enabled(struct clk_hw *hw)
+{
+	struct isc_clk *isc_clk = to_isc_clk(hw);
+	u32 status;
+	int ret;
+
+	ret = pm_runtime_resume_and_get(isc_clk->dev);
+	if (ret < 0)
+		return 0;
+
+	regmap_read(isc_clk->regmap, ISC_CLKSR, &status);
+
+	pm_runtime_put_sync(isc_clk->dev);
+
+	return status & ISC_CLK(isc_clk->id) ? 1 : 0;
+}
+
+static unsigned long
+isc_clk_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
+{
+	struct isc_clk *isc_clk = to_isc_clk(hw);
+
+	return DIV_ROUND_CLOSEST(parent_rate, isc_clk->div + 1);
+}
+
+static int isc_clk_determine_rate(struct clk_hw *hw,
+				  struct clk_rate_request *req)
+{
+	struct isc_clk *isc_clk = to_isc_clk(hw);
+	long best_rate = -EINVAL;
+	int best_diff = -1;
+	unsigned int i, div;
+
+	for (i = 0; i < clk_hw_get_num_parents(hw); i++) {
+		struct clk_hw *parent;
+		unsigned long parent_rate;
+
+		parent = clk_hw_get_parent_by_index(hw, i);
+		if (!parent)
+			continue;
+
+		parent_rate = clk_hw_get_rate(parent);
+		if (!parent_rate)
+			continue;
+
+		for (div = 1; div < ISC_CLK_MAX_DIV + 2; div++) {
+			unsigned long rate;
+			int diff;
+
+			rate = DIV_ROUND_CLOSEST(parent_rate, div);
+			diff = abs(req->rate - rate);
+
+			if (best_diff < 0 || best_diff > diff) {
+				best_rate = rate;
+				best_diff = diff;
+				req->best_parent_rate = parent_rate;
+				req->best_parent_hw = parent;
+			}
+
+			if (!best_diff || rate < req->rate)
+				break;
+		}
+
+		if (!best_diff)
+			break;
+	}
+
+	dev_dbg(isc_clk->dev,
+		"ISC CLK: %s, best_rate = %ld, parent clk: %s @ %ld\n",
+		__func__, best_rate,
+		__clk_get_name((req->best_parent_hw)->clk),
+		req->best_parent_rate);
+
+	if (best_rate < 0)
+		return best_rate;
+
+	req->rate = best_rate;
+
+	return 0;
+}
+
+static int isc_clk_set_parent(struct clk_hw *hw, u8 index)
+{
+	struct isc_clk *isc_clk = to_isc_clk(hw);
+
+	if (index >= clk_hw_get_num_parents(hw))
+		return -EINVAL;
+
+	isc_clk->parent_id = index;
+
+	return 0;
+}
+
+static u8 isc_clk_get_parent(struct clk_hw *hw)
+{
+	struct isc_clk *isc_clk = to_isc_clk(hw);
+
+	return isc_clk->parent_id;
+}
+
+static int isc_clk_set_rate(struct clk_hw *hw,
+			    unsigned long rate,
+			    unsigned long parent_rate)
+{
+	struct isc_clk *isc_clk = to_isc_clk(hw);
+	u32 div;
+
+	if (!rate)
+		return -EINVAL;
+
+	div = DIV_ROUND_CLOSEST(parent_rate, rate);
+	if (div > (ISC_CLK_MAX_DIV + 1) || !div)
+		return -EINVAL;
+
+	isc_clk->div = div - 1;
+
+	return 0;
+}
+
+static const struct clk_ops isc_clk_ops = {
+	.prepare	= isc_clk_prepare,
+	.unprepare	= isc_clk_unprepare,
+	.enable		= isc_clk_enable,
+	.disable	= isc_clk_disable,
+	.is_enabled	= isc_clk_is_enabled,
+	.recalc_rate	= isc_clk_recalc_rate,
+	.determine_rate	= isc_clk_determine_rate,
+	.set_parent	= isc_clk_set_parent,
+	.get_parent	= isc_clk_get_parent,
+	.set_rate	= isc_clk_set_rate,
+};
+
+static int isc_clk_register(struct isc_device *isc, unsigned int id)
+{
+	struct regmap *regmap = isc->regmap;
+	struct device_node *np = isc->dev->of_node;
+	struct isc_clk *isc_clk;
+	struct clk_init_data init;
+	const char *clk_name = np->name;
+	const char *parent_names[3];
+	int num_parents;
+
+	if (id == ISC_ISPCK && !isc->ispck_required)
+		return 0;
+
+	num_parents = of_clk_get_parent_count(np);
+	if (num_parents < 1 || num_parents > 3)
+		return -EINVAL;
+
+	if (num_parents > 2 && id == ISC_ISPCK)
+		num_parents = 2;
+
+	of_clk_parent_fill(np, parent_names, num_parents);
+
+	if (id == ISC_MCK)
+		of_property_read_string(np, "clock-output-names", &clk_name);
+	else
+		clk_name = "isc-ispck";
+
+	init.parent_names	= parent_names;
+	init.num_parents	= num_parents;
+	init.name		= clk_name;
+	init.ops		= &isc_clk_ops;
+	init.flags		= CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE;
+
+	isc_clk = &isc->isc_clks[id];
+	isc_clk->hw.init	= &init;
+	isc_clk->regmap		= regmap;
+	isc_clk->id		= id;
+	isc_clk->dev		= isc->dev;
+	spin_lock_init(&isc_clk->lock);
+
+	isc_clk->clk = clk_register(isc->dev, &isc_clk->hw);
+	if (IS_ERR(isc_clk->clk)) {
+		dev_err(isc->dev, "%s: clock register fail\n", clk_name);
+		return PTR_ERR(isc_clk->clk);
+	} else if (id == ISC_MCK) {
+		of_clk_add_provider(np, of_clk_src_simple_get, isc_clk->clk);
+	}
+
+	return 0;
+}
+
+int microchip_isc_clk_init(struct isc_device *isc)
+{
+	unsigned int i;
+	int ret;
+
+	for (i = 0; i < ARRAY_SIZE(isc->isc_clks); i++)
+		isc->isc_clks[i].clk = ERR_PTR(-EINVAL);
+
+	for (i = 0; i < ARRAY_SIZE(isc->isc_clks); i++) {
+		ret = isc_clk_register(isc, i);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(microchip_isc_clk_init);
+
+void microchip_isc_clk_cleanup(struct isc_device *isc)
+{
+	unsigned int i;
+
+	of_clk_del_provider(isc->dev->of_node);
+
+	for (i = 0; i < ARRAY_SIZE(isc->isc_clks); i++) {
+		struct isc_clk *isc_clk = &isc->isc_clks[i];
+
+		if (!IS_ERR(isc_clk->clk))
+			clk_unregister(isc_clk->clk);
+	}
+}
+EXPORT_SYMBOL_GPL(microchip_isc_clk_cleanup);