Linux-libre 4.2-gnu

1 files changed, 272 insertions, 0 deletions

diff --git a/drivers/clk/bcm/clk-iproc-asiu.c b/drivers/clk/bcm/clk-iproc-asiu.c
new file mode 100644
index 000000000..f630e1bbd
--- /dev/null
+++ b/drivers/clk/bcm/clk-iproc-asiu.c
@@ -0,0 +1,272 @@
+/*
+ * Copyright (C) 2014 Broadcom Corporation
+ *
+ * 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 version 2.
+ *
+ * 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/kernel.h>
+#include <linux/err.h>
+#include <linux/clk-provider.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/clkdev.h>
+#include <linux/of_address.h>
+#include <linux/delay.h>
+
+#include "clk-iproc.h"
+
+struct iproc_asiu;
+
+struct iproc_asiu_clk {
+	struct clk_hw hw;
+	const char *name;
+	struct iproc_asiu *asiu;
+	unsigned long rate;
+	struct iproc_asiu_div div;
+	struct iproc_asiu_gate gate;
+};
+
+struct iproc_asiu {
+	void __iomem *div_base;
+	void __iomem *gate_base;
+
+	struct clk_onecell_data clk_data;
+	struct iproc_asiu_clk *clks;
+};
+
+#define to_asiu_clk(hw) container_of(hw, struct iproc_asiu_clk, hw)
+
+static int iproc_asiu_clk_enable(struct clk_hw *hw)
+{
+	struct iproc_asiu_clk *clk = to_asiu_clk(hw);
+	struct iproc_asiu *asiu = clk->asiu;
+	u32 val;
+
+	/* some clocks at the ASIU level are always enabled */
+	if (clk->gate.offset == IPROC_CLK_INVALID_OFFSET)
+		return 0;
+
+	val = readl(asiu->gate_base + clk->gate.offset);
+	val |= (1 << clk->gate.en_shift);
+	writel(val, asiu->gate_base + clk->gate.offset);
+
+	return 0;
+}
+
+static void iproc_asiu_clk_disable(struct clk_hw *hw)
+{
+	struct iproc_asiu_clk *clk = to_asiu_clk(hw);
+	struct iproc_asiu *asiu = clk->asiu;
+	u32 val;
+
+	/* some clocks at the ASIU level are always enabled */
+	if (clk->gate.offset == IPROC_CLK_INVALID_OFFSET)
+		return;
+
+	val = readl(asiu->gate_base + clk->gate.offset);
+	val &= ~(1 << clk->gate.en_shift);
+	writel(val, asiu->gate_base + clk->gate.offset);
+}
+
+static unsigned long iproc_asiu_clk_recalc_rate(struct clk_hw *hw,
+						unsigned long parent_rate)
+{
+	struct iproc_asiu_clk *clk = to_asiu_clk(hw);
+	struct iproc_asiu *asiu = clk->asiu;
+	u32 val;
+	unsigned int div_h, div_l;
+
+	if (parent_rate == 0) {
+		clk->rate = 0;
+		return 0;
+	}
+
+	/* if clock divisor is not enabled, simply return parent rate */
+	val = readl(asiu->div_base + clk->div.offset);
+	if ((val & (1 << clk->div.en_shift)) == 0) {
+		clk->rate = parent_rate;
+		return parent_rate;
+	}
+
+	/* clock rate = parent rate / (high_div + 1) + (low_div + 1) */
+	div_h = (val >> clk->div.high_shift) & bit_mask(clk->div.high_width);
+	div_h++;
+	div_l = (val >> clk->div.low_shift) & bit_mask(clk->div.low_width);
+	div_l++;
+
+	clk->rate = parent_rate / (div_h + div_l);
+	pr_debug("%s: rate: %lu. parent rate: %lu div_h: %u div_l: %u\n",
+		 __func__, clk->rate, parent_rate, div_h, div_l);
+
+	return clk->rate;
+}
+
+static long iproc_asiu_clk_round_rate(struct clk_hw *hw, unsigned long rate,
+				      unsigned long *parent_rate)
+{
+	unsigned int div;
+
+	if (rate == 0 || *parent_rate == 0)
+		return -EINVAL;
+
+	if (rate == *parent_rate)
+		return *parent_rate;
+
+	div = DIV_ROUND_UP(*parent_rate, rate);
+	if (div < 2)
+		return *parent_rate;
+
+	return *parent_rate / div;
+}
+
+static int iproc_asiu_clk_set_rate(struct clk_hw *hw, unsigned long rate,
+				   unsigned long parent_rate)
+{
+	struct iproc_asiu_clk *clk = to_asiu_clk(hw);
+	struct iproc_asiu *asiu = clk->asiu;
+	unsigned int div, div_h, div_l;
+	u32 val;
+
+	if (rate == 0 || parent_rate == 0)
+		return -EINVAL;
+
+	/* simply disable the divisor if one wants the same rate as parent */
+	if (rate == parent_rate) {
+		val = readl(asiu->div_base + clk->div.offset);
+		val &= ~(1 << clk->div.en_shift);
+		writel(val, asiu->div_base + clk->div.offset);
+		return 0;
+	}
+
+	div = DIV_ROUND_UP(parent_rate, rate);
+	if (div < 2)
+		return -EINVAL;
+
+	div_h = div_l = div >> 1;
+	div_h--;
+	div_l--;
+
+	val = readl(asiu->div_base + clk->div.offset);
+	val |= 1 << clk->div.en_shift;
+	if (div_h) {
+		val &= ~(bit_mask(clk->div.high_width)
+			 << clk->div.high_shift);
+		val |= div_h << clk->div.high_shift;
+	} else {
+		val &= ~(bit_mask(clk->div.high_width)
+			 << clk->div.high_shift);
+	}
+	if (div_l) {
+		val &= ~(bit_mask(clk->div.low_width) << clk->div.low_shift);
+		val |= div_l << clk->div.low_shift;
+	} else {
+		val &= ~(bit_mask(clk->div.low_width) << clk->div.low_shift);
+	}
+	writel(val, asiu->div_base + clk->div.offset);
+
+	return 0;
+}
+
+static const struct clk_ops iproc_asiu_ops = {
+	.enable = iproc_asiu_clk_enable,
+	.disable = iproc_asiu_clk_disable,
+	.recalc_rate = iproc_asiu_clk_recalc_rate,
+	.round_rate = iproc_asiu_clk_round_rate,
+	.set_rate = iproc_asiu_clk_set_rate,
+};
+
+void __init iproc_asiu_setup(struct device_node *node,
+			     const struct iproc_asiu_div *div,
+			     const struct iproc_asiu_gate *gate,
+			     unsigned int num_clks)
+{
+	int i, ret;
+	struct iproc_asiu *asiu;
+
+	if (WARN_ON(!gate || !div))
+		return;
+
+	asiu = kzalloc(sizeof(*asiu), GFP_KERNEL);
+	if (WARN_ON(!asiu))
+		return;
+
+	asiu->clk_data.clk_num = num_clks;
+	asiu->clk_data.clks = kcalloc(num_clks, sizeof(*asiu->clk_data.clks),
+				      GFP_KERNEL);
+	if (WARN_ON(!asiu->clk_data.clks))
+		goto err_clks;
+
+	asiu->clks = kcalloc(num_clks, sizeof(*asiu->clks), GFP_KERNEL);
+	if (WARN_ON(!asiu->clks))
+		goto err_asiu_clks;
+
+	asiu->div_base = of_iomap(node, 0);
+	if (WARN_ON(!asiu->div_base))
+		goto err_iomap_div;
+
+	asiu->gate_base = of_iomap(node, 1);
+	if (WARN_ON(!asiu->gate_base))
+		goto err_iomap_gate;
+
+	for (i = 0; i < num_clks; i++) {
+		struct clk_init_data init;
+		struct clk *clk;
+		const char *parent_name;
+		struct iproc_asiu_clk *asiu_clk;
+		const char *clk_name;
+
+		ret = of_property_read_string_index(node, "clock-output-names",
+						    i, &clk_name);
+		if (WARN_ON(ret))
+			goto err_clk_register;
+
+		asiu_clk = &asiu->clks[i];
+		asiu_clk->name = clk_name;
+		asiu_clk->asiu = asiu;
+		asiu_clk->div = div[i];
+		asiu_clk->gate = gate[i];
+		init.name = clk_name;
+		init.ops = &iproc_asiu_ops;
+		init.flags = 0;
+		parent_name = of_clk_get_parent_name(node, 0);
+		init.parent_names = (parent_name ? &parent_name : NULL);
+		init.num_parents = (parent_name ? 1 : 0);
+		asiu_clk->hw.init = &init;
+
+		clk = clk_register(NULL, &asiu_clk->hw);
+		if (WARN_ON(IS_ERR(clk)))
+			goto err_clk_register;
+		asiu->clk_data.clks[i] = clk;
+	}
+
+	ret = of_clk_add_provider(node, of_clk_src_onecell_get,
+				  &asiu->clk_data);
+	if (WARN_ON(ret))
+		goto err_clk_register;
+
+	return;
+
+err_clk_register:
+	for (i = 0; i < num_clks; i++)
+		clk_unregister(asiu->clk_data.clks[i]);
+	iounmap(asiu->gate_base);
+
+err_iomap_gate:
+	iounmap(asiu->div_base);
+
+err_iomap_div:
+	kfree(asiu->clks);
+
+err_asiu_clks:
+	kfree(asiu->clk_data.clks);
+
+err_clks:
+	kfree(asiu);
+}