[PATCH linux-next v1 1/4] clk: renesas: clk-avb: add AVB Clock driver

[<jiada_wang@mentor.com>]

From: Jiada Wang <jiada_wang@mentor.com>

There are AVB Counter Clocks, each clock has 12bits integral
and 8 bits fractional dividers which operates with S0D1ϕ clock.

This patch adds avb clock provider, which registers all 8 AVB
Counter Clocks, and provide them via clock provider.

Signed-off-by: Jiada Wang <jiada_wang@mentor.com>
---
 drivers/clk/renesas/Kconfig   |   6 +
 drivers/clk/renesas/Makefile  |   1 +
 drivers/clk/renesas/clk-avb.c | 257 ++++++++++++++++++++++++++++++++++
 3 files changed, 264 insertions(+)
 create mode 100644 drivers/clk/renesas/clk-avb.c

diff --git a/drivers/clk/renesas/Kconfig b/drivers/clk/renesas/Kconfig
index f998a7333acb..afa7b20b44a9 100644
--- a/drivers/clk/renesas/Kconfig
+++ b/drivers/clk/renesas/Kconfig
@@ -173,4 +173,10 @@ config CLK_RENESAS_CPG_MSTP
 config CLK_RENESAS_DIV6
 	bool "DIV6 clock support" if COMPILE_TEST
 
+config CLK_RENESAS_CLK_AVB
+	bool "Renesas AVB Counter Clocks"
+	depends on CLK_RENESAS_CPG_MSSR
+	default y if ARCH_R8A7795
+	default y if ARCH_R8A7796
+
 endif # CLK_RENESAS
diff --git a/drivers/clk/renesas/Makefile b/drivers/clk/renesas/Makefile
index 71d4cafe15c0..17b05955e4f4 100644
--- a/drivers/clk/renesas/Makefile
+++ b/drivers/clk/renesas/Makefile
@@ -34,3 +34,4 @@ obj-$(CONFIG_CLK_RCAR_USB2_CLOCK_SEL)	+= rcar-usb2-clock-sel.o
 obj-$(CONFIG_CLK_RENESAS_CPG_MSSR)	+= renesas-cpg-mssr.o
 obj-$(CONFIG_CLK_RENESAS_CPG_MSTP)	+= clk-mstp.o
 obj-$(CONFIG_CLK_RENESAS_DIV6)		+= clk-div6.o
+obj-$(CONFIG_CLK_RENESAS_CLK_AVB)	+= clk-avb.o
diff --git a/drivers/clk/renesas/clk-avb.c b/drivers/clk/renesas/clk-avb.c
new file mode 100644
index 000000000000..bb1eef0e9bee
--- /dev/null
+++ b/drivers/clk/renesas/clk-avb.c
@@ -0,0 +1,257 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2017  Mentor
+ *
+ * Contact: Jiada Wang <jiada_wang@mentor.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; version 2 of the License.
+ *
+ * avb Common Clock Framework support
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+#include <linux/slab.h>
+
+struct clk_avb_data {
+	void __iomem *base;
+
+	struct clk_onecell_data clk_data;
+	/* lock reg access */
+	spinlock_t lock;
+};
+
+struct clk_avb {
+	struct clk_hw hw;
+	unsigned int idx;
+	struct clk_avb_data *data;
+};
+
+#define to_clk_avb(_hw) container_of(_hw, struct clk_avb, hw)
+
+#define AVB_DIV_MASK	0x3ffff
+#define AVB_MAX_DIV	0x3ffc0
+#define AVB_COUNTER_MAX_FREQ	25000000
+#define AVB_COUNTER_NUM		8
+#define AVB_CLK_NAME_SIZE	10
+#define AVB_ID_TO_DIV(id)	((id) * 4)
+
+#define AVB_CLK_CONFIG		0x20
+#define AVB_DIV_EN_COM		BIT(31)
+#define AVB_CLK_NAME		"avb"
+#define ADG_CLK_NAME		"adg"
+
+static int clk_avb_is_enabled(struct clk_hw *hw)
+{
+	struct clk_avb *avb = to_clk_avb(hw);
+
+	return (clk_readl(avb->data->base + AVB_CLK_CONFIG) & BIT(avb->idx));
+}
+
+static int clk_avb_enabledisable(struct clk_hw *hw, int enable)
+{
+	struct clk_avb *avb = to_clk_avb(hw);
+	u32 val;
+
+	spin_lock(&avb->data->lock);
+
+	val = clk_readl(avb->data->base + AVB_CLK_CONFIG);
+	if (enable)
+		val |= BIT(avb->idx);
+	else
+		val &= ~BIT(avb->idx);
+	clk_writel(val, avb->data->base + AVB_CLK_CONFIG);
+
+	spin_unlock(&avb->data->lock);
+
+	return 0;
+}
+
+static int clk_avb_enable(struct clk_hw *hw)
+{
+	return clk_avb_enabledisable(hw, 1);
+}
+
+static void clk_avb_disable(struct clk_hw *hw)
+{
+	clk_avb_enabledisable(hw, 0);
+}
+
+static unsigned long clk_avb_recalc_rate(struct clk_hw *hw,
+					 unsigned long parent_rate)
+{
+	struct clk_avb *avb = to_clk_avb(hw);
+	u32 div;
+
+	div = clk_readl(avb->data->base + AVB_ID_TO_DIV(avb->idx)) &
+			AVB_DIV_MASK;
+	if (!div)
+		return parent_rate;
+
+	return parent_rate * 32 / div;
+}
+
+static unsigned int clk_avb_calc_div(unsigned long rate,
+				     unsigned long parent_rate)
+{
+	unsigned int div;
+
+	if (!rate)
+		rate = 1;
+
+	if (rate > AVB_COUNTER_MAX_FREQ)
+		rate = AVB_COUNTER_MAX_FREQ;
+
+	div = DIV_ROUND_CLOSEST(parent_rate * 32, rate);
+
+	if (div > AVB_MAX_DIV)
+		div = AVB_MAX_DIV;
+
+	return div;
+}
+
+static long clk_avb_round_rate(struct clk_hw *hw, unsigned long rate,
+			       unsigned long *parent_rate)
+{
+	unsigned int div = clk_avb_calc_div(rate, *parent_rate);
+
+	return (*parent_rate * 32) / div;
+}
+
+static int clk_avb_set_rate(struct clk_hw *hw, unsigned long rate,
+			    unsigned long parent_rate)
+{
+	struct clk_avb *avb = to_clk_avb(hw);
+	unsigned int div = clk_avb_calc_div(rate, parent_rate);
+	u32 val;
+
+	val = clk_readl(avb->data->base + AVB_ID_TO_DIV(avb->idx)) &
+			~AVB_DIV_MASK;
+	clk_writel(val | div, avb->data->base + AVB_ID_TO_DIV(avb->idx));
+
+	return 0;
+}
+
+static const struct clk_ops clk_avb_ops = {
+	.enable = clk_avb_enable,
+	.disable = clk_avb_disable,
+	.is_enabled = clk_avb_is_enabled,
+	.recalc_rate = clk_avb_recalc_rate,
+	.round_rate = clk_avb_round_rate,
+	.set_rate = clk_avb_set_rate,
+};
+
+static struct clk *clk_register_avb(struct clk_avb_data *data,
+				    unsigned int id)
+{
+	struct clk_init_data init;
+	struct clk_avb *avb;
+	struct clk *clk;
+	char name[AVB_CLK_NAME_SIZE];
+	const char *parent_name = ADG_CLK_NAME;
+
+	avb = kzalloc(sizeof(*avb), GFP_KERNEL);
+	if (!avb)
+		return ERR_PTR(-ENOMEM);
+
+	snprintf(name, AVB_CLK_NAME_SIZE, "%s.%u", AVB_CLK_NAME, id);
+
+	avb->idx = id;
+	avb->data = data;
+
+	/* Register the clock. */
+	init.name = name;
+	init.ops = &clk_avb_ops;
+	init.flags = CLK_IS_BASIC;
+	init.parent_names = &parent_name;
+	init.num_parents = 1;
+
+	avb->hw.init = &init;
+
+	/* init DIV to a valid state */
+	writel(AVB_MAX_DIV, data->base + AVB_ID_TO_DIV(avb->idx));
+
+	clk = clk_register(NULL, &avb->hw);
+	if (IS_ERR(clk))
+		kfree(avb);
+
+	return clk;
+}
+
+static void clk_unregister_avb(struct clk *clk)
+{
+	struct clk_avb *avb;
+	struct clk_hw *hw;
+
+	if (IS_ERR(clk))
+		return;
+
+	hw = __clk_get_hw(clk);
+	if (!hw)
+		return;
+
+	avb = to_clk_avb(hw);
+
+	clk_unregister(clk);
+	kfree(avb);
+}
+
+static void __init clk_avb_setup(struct device_node *node)
+{
+	struct clk_avb_data *data;
+	struct clk_onecell_data *clk_data;
+	int ret, i;
+	struct resource res;
+
+	data = kzalloc(sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return;
+
+	data->base = of_io_request_and_map(node, 0, of_node_full_name(node));
+	if (IS_ERR(data->base))
+		goto err_data;
+
+	spin_lock_init(&data->lock);
+
+	clk_data = &data->clk_data;
+	clk_data->clk_num = AVB_COUNTER_NUM;
+	clk_data->clks = kmalloc_array(AVB_COUNTER_NUM,
+				       sizeof(struct clk *),
+				       GFP_KERNEL);
+	if (!clk_data->clks)
+		goto err_unmap;
+
+	for (i = 0; i < AVB_COUNTER_NUM; i++) {
+		clk_data->clks[i] = clk_register_avb(data, i);
+		if (IS_ERR(clk_data->clks[i])) {
+			pr_err("failed to register clock %s.%d\n",
+			       AVB_CLK_NAME, i);
+			goto err_clks;
+		}
+	}
+
+	ret = of_clk_add_provider(node, of_clk_src_onecell_get, clk_data);
+	if (ret) {
+		pr_err("failed to register clock provider\n");
+		goto err_clks;
+	}
+
+	writel(AVB_DIV_EN_COM, data->base + AVB_CLK_CONFIG);
+
+	return;
+
+err_clks:
+	for (i = 0; i < AVB_COUNTER_NUM; i++)
+		clk_unregister_avb(clk_data->clks[i]);
+err_unmap:
+	iounmap(data->base);
+	of_address_to_resource(node, 0, &res);
+	release_mem_region(res.start, resource_size(&res));
+err_data:
+	kfree(data);
+}
+
+CLK_OF_DECLARE(avb, "renesas,clk-avb", clk_avb_setup);
-- 
2.17.0