Fixed MTP to work with TWRP

drivers/clk/clk-fixed-factor.c

@@ -0,0 +1,136 @@
+/*
+ * Copyright (C) 2011 Sascha Hauer, Pengutronix <s.hauer@pengutronix.de>
+ *
+ * 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.
+ *
+ * Standard functionality for the common clock API.
+ */
+#include <linux/module.h>
+#include <linux/clk-provider.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/of.h>
+
+/*
+ * DOC: basic fixed multiplier and divider clock that cannot gate
+ *
+ * Traits of this clock:
+ * prepare - clk_prepare only ensures that parents are prepared
+ * enable - clk_enable only ensures that parents are enabled
+ * rate - rate is fixed.  clk->rate = parent->rate / div * mult
+ * parent - fixed parent.  No clk_set_parent support
+ */
+
+#define to_clk_fixed_factor(_hw) container_of(_hw, struct clk_fixed_factor, hw)
+
+static unsigned long clk_factor_recalc_rate(struct clk_hw *hw,
+		unsigned long parent_rate)
+{
+	struct clk_fixed_factor *fix = to_clk_fixed_factor(hw);
+	unsigned long long int rate;
+
+	rate = (unsigned long long int)parent_rate * fix->mult;
+	do_div(rate, fix->div);
+	return (unsigned long)rate;
+}
+
+static long clk_factor_round_rate(struct clk_hw *hw, unsigned long rate,
+				unsigned long *prate)
+{
+	struct clk_fixed_factor *fix = to_clk_fixed_factor(hw);
+
+	if (__clk_get_flags(hw->clk) & CLK_SET_RATE_PARENT) {
+		unsigned long best_parent;
+
+		best_parent = (rate / fix->mult) * fix->div;
+		*prate = __clk_round_rate(__clk_get_parent(hw->clk),
+				best_parent);
+	}
+
+	return (*prate / fix->div) * fix->mult;
+}
+
+static int clk_factor_set_rate(struct clk_hw *hw, unsigned long rate,
+				unsigned long parent_rate)
+{
+	return 0;
+}
+
+struct clk_ops clk_fixed_factor_ops = {
+	.round_rate = clk_factor_round_rate,
+	.set_rate = clk_factor_set_rate,
+	.recalc_rate = clk_factor_recalc_rate,
+};
+EXPORT_SYMBOL_GPL(clk_fixed_factor_ops);
+
+struct clk *clk_register_fixed_factor(struct device *dev, const char *name,
+		const char *parent_name, unsigned long flags,
+		unsigned int mult, unsigned int div)
+{
+	struct clk_fixed_factor *fix;
+	struct clk_init_data init;
+	struct clk *clk;
+
+	fix = kmalloc(sizeof(*fix), GFP_KERNEL);
+	if (!fix) {
+		pr_err("%s: could not allocate fixed factor clk\n", __func__);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	/* struct clk_fixed_factor assignments */
+	fix->mult = mult;
+	fix->div = div;
+	fix->hw.init = &init;
+
+	init.name = name;
+	init.ops = &clk_fixed_factor_ops;
+	init.flags = flags | CLK_IS_BASIC;
+	init.parent_names = &parent_name;
+	init.num_parents = 1;
+
+	clk = clk_register(dev, &fix->hw);
+
+	if (IS_ERR(clk))
+		kfree(fix);
+
+	return clk;
+}
+EXPORT_SYMBOL_GPL(clk_register_fixed_factor);
+
+#ifdef CONFIG_OF
+/**
+ * of_fixed_factor_clk_setup() - Setup function for simple fixed factor clock
+ */
+void __init of_fixed_factor_clk_setup(struct device_node *node)
+{
+	struct clk *clk;
+	const char *clk_name = node->name;
+	const char *parent_name;
+	u32 div, mult;
+
+	if (of_property_read_u32(node, "clock-div", &div)) {
+		pr_err("%s Fixed factor clock <%s> must have a clock-div property\n",
+			__func__, node->name);
+		return;
+	}
+
+	if (of_property_read_u32(node, "clock-mult", &mult)) {
+		pr_err("%s Fixed factor clock <%s> must have a clock-mult property\n",
+			__func__, node->name);
+		return;
+	}
+
+	of_property_read_string(node, "clock-output-names", &clk_name);
+	parent_name = of_clk_get_parent_name(node, 0);
+
+	clk = clk_register_fixed_factor(NULL, clk_name, parent_name, 0,
+					mult, div);
+	if (!IS_ERR(clk))
+		of_clk_add_provider(node, of_clk_src_simple_get, clk);
+}
+EXPORT_SYMBOL_GPL(of_fixed_factor_clk_setup);
+CLK_OF_DECLARE(fixed_factor_clk, "fixed-factor-clock",
+		of_fixed_factor_clk_setup);
+#endif