clk: Loongson1: Refactor Loongson1 clock

Factor out the common functions into loongson1/clk.c
to support both Loongson1B and Loongson1C. And, put
the rest into loongson1/clk-loongson1b.c.

Signed-off-by: Kelvin Cheung <keguang.zhang@gmail.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

4 files changed, 183 insertions, 0 deletions

diff --git a/drivers/clk/loongson1/Makefile b/drivers/clk/loongson1/Makefile
new file mode 100644
index 000000000000..5a162a1b9bf6
--- /dev/null
+++ b/drivers/clk/loongson1/Makefile
@@ -0,0 +1,2 @@
+obj-y				+= clk.o
+obj-$(CONFIG_LOONGSON1_LS1B)	+= clk-loongson1b.o
diff --git a/drivers/clk/loongson1/clk-loongson1b.c b/drivers/clk/loongson1/clk-loongson1b.c
new file mode 100644
index 000000000000..5b6817ee594d
--- /dev/null
+++ b/drivers/clk/loongson1/clk-loongson1b.c
@@ -0,0 +1,119 @@
+/*
+ * Copyright (c) 2012-2016 Zhang, Keguang <keguang.zhang@gmail.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.
+ */
+
+#include <linux/clkdev.h>
+#include <linux/clk-provider.h>
+#include <linux/io.h>
+#include <linux/err.h>
+
+#include <loongson1.h>
+#include "clk.h"
+
+#define OSC		(33 * 1000000)
+#define DIV_APB		2
+
+static DEFINE_SPINLOCK(_lock);
+
+static unsigned long ls1x_pll_recalc_rate(struct clk_hw *hw,
+					  unsigned long parent_rate)
+{
+	u32 pll, rate;
+
+	pll = __raw_readl(LS1X_CLK_PLL_FREQ);
+	rate = 12 + (pll & 0x3f) + (((pll >> 8) & 0x3ff) >> 10);
+	rate *= OSC;
+	rate >>= 1;
+
+	return rate;
+}
+
+static const struct clk_ops ls1x_pll_clk_ops = {
+	.recalc_rate = ls1x_pll_recalc_rate,
+};
+
+static const char * const cpu_parents[] = { "cpu_clk_div", "osc_33m_clk", };
+static const char * const ahb_parents[] = { "ahb_clk_div", "osc_33m_clk", };
+static const char * const dc_parents[] = { "dc_clk_div", "osc_33m_clk", };
+
+void __init ls1x_clk_init(void)
+{
+	struct clk_hw *hw;
+
+	hw = clk_hw_register_fixed_rate(NULL, "osc_33m_clk", NULL, 0, OSC);
+	clk_hw_register_clkdev(hw, "osc_33m_clk", NULL);
+
+	/* clock derived from 33 MHz OSC clk */
+	hw = clk_hw_register_pll(NULL, "pll_clk", "osc_33m_clk",
+				 &ls1x_pll_clk_ops, 0);
+	clk_hw_register_clkdev(hw, "pll_clk", NULL);
+
+	/* clock derived from PLL clk */
+	/*                                 _____
+	 *         _______________________|     |
+	 * OSC ___/                       | MUX |___ CPU CLK
+	 *        \___ PLL ___ CPU DIV ___|     |
+	 *                                |_____|
+	 */
+	hw = clk_hw_register_divider(NULL, "cpu_clk_div", "pll_clk",
+				   CLK_GET_RATE_NOCACHE, LS1X_CLK_PLL_DIV,
+				   DIV_CPU_SHIFT, DIV_CPU_WIDTH,
+				   CLK_DIVIDER_ONE_BASED |
+				   CLK_DIVIDER_ROUND_CLOSEST, &_lock);
+	clk_hw_register_clkdev(hw, "cpu_clk_div", NULL);
+	hw = clk_hw_register_mux(NULL, "cpu_clk", cpu_parents,
+			       ARRAY_SIZE(cpu_parents),
+			       CLK_SET_RATE_NO_REPARENT, LS1X_CLK_PLL_DIV,
+			       BYPASS_CPU_SHIFT, BYPASS_CPU_WIDTH, 0, &_lock);
+	clk_hw_register_clkdev(hw, "cpu_clk", NULL);
+
+	/*                                 _____
+	 *         _______________________|     |
+	 * OSC ___/                       | MUX |___ DC  CLK
+	 *        \___ PLL ___ DC  DIV ___|     |
+	 *                                |_____|
+	 */
+	hw = clk_hw_register_divider(NULL, "dc_clk_div", "pll_clk",
+				   0, LS1X_CLK_PLL_DIV, DIV_DC_SHIFT,
+				   DIV_DC_WIDTH, CLK_DIVIDER_ONE_BASED, &_lock);
+	clk_hw_register_clkdev(hw, "dc_clk_div", NULL);
+	hw = clk_hw_register_mux(NULL, "dc_clk", dc_parents,
+			       ARRAY_SIZE(dc_parents),
+			       CLK_SET_RATE_NO_REPARENT, LS1X_CLK_PLL_DIV,
+			       BYPASS_DC_SHIFT, BYPASS_DC_WIDTH, 0, &_lock);
+	clk_hw_register_clkdev(hw, "dc_clk", NULL);
+
+	/*                                 _____
+	 *         _______________________|     |
+	 * OSC ___/                       | MUX |___ DDR CLK
+	 *        \___ PLL ___ DDR DIV ___|     |
+	 *                                |_____|
+	 */
+	hw = clk_hw_register_divider(NULL, "ahb_clk_div", "pll_clk",
+				   0, LS1X_CLK_PLL_DIV, DIV_DDR_SHIFT,
+				   DIV_DDR_WIDTH, CLK_DIVIDER_ONE_BASED,
+				   &_lock);
+	clk_hw_register_clkdev(hw, "ahb_clk_div", NULL);
+	hw = clk_hw_register_mux(NULL, "ahb_clk", ahb_parents,
+			       ARRAY_SIZE(ahb_parents),
+			       CLK_SET_RATE_NO_REPARENT, LS1X_CLK_PLL_DIV,
+			       BYPASS_DDR_SHIFT, BYPASS_DDR_WIDTH, 0, &_lock);
+	clk_hw_register_clkdev(hw, "ahb_clk", NULL);
+	clk_hw_register_clkdev(hw, "stmmaceth", NULL);
+
+	/* clock derived from AHB clk */
+	/* APB clk is always half of the AHB clk */
+	hw = clk_hw_register_fixed_factor(NULL, "apb_clk", "ahb_clk", 0, 1,
+					DIV_APB);
+	clk_hw_register_clkdev(hw, "apb_clk", NULL);
+	clk_hw_register_clkdev(hw, "ls1x_i2c", NULL);
+	clk_hw_register_clkdev(hw, "ls1x_pwmtimer", NULL);
+	clk_hw_register_clkdev(hw, "ls1x_spi", NULL);
+	clk_hw_register_clkdev(hw, "ls1x_wdt", NULL);
+	clk_hw_register_clkdev(hw, "serial8250", NULL);
+}
diff --git a/drivers/clk/loongson1/clk.c b/drivers/clk/loongson1/clk.c
new file mode 100644
index 000000000000..cfcfd143fccb
--- /dev/null
+++ b/drivers/clk/loongson1/clk.c
@@ -0,0 +1,43 @@
+/*
+ * Copyright (c) 2012-2016 Zhang, Keguang <keguang.zhang@gmail.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.
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/slab.h>
+
+struct clk_hw *__init clk_hw_register_pll(struct device *dev,
+					  const char *name,
+					  const char *parent_name,
+					  const struct clk_ops *ops,
+					  unsigned long flags)
+{
+	int ret;
+	struct clk_hw *hw;
+	struct clk_init_data init;
+
+	/* allocate the divider */
+	hw = kzalloc(sizeof(*hw), GFP_KERNEL);
+	if (!hw)
+		return ERR_PTR(-ENOMEM);
+
+	init.name = name;
+	init.ops = ops;
+	init.flags = flags | CLK_IS_BASIC;
+	init.parent_names = (parent_name ? &parent_name : NULL);
+	init.num_parents = (parent_name ? 1 : 0);
+	hw->init = &init;
+
+	/* register the clock */
+	ret = clk_hw_register(dev, hw);
+	if (ret) {
+		kfree(hw);
+		hw = ERR_PTR(ret);
+	}
+
+	return hw;
+}
diff --git a/drivers/clk/loongson1/clk.h b/drivers/clk/loongson1/clk.h
new file mode 100644
index 000000000000..085d74b5d496
--- /dev/null
+++ b/drivers/clk/loongson1/clk.h
@@ -0,0 +1,19 @@
+/*
+ * Copyright (c) 2012-2016 Zhang, Keguang <keguang.zhang@gmail.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.
+ */
+
+#ifndef __LOONGSON1_CLK_H
+#define __LOONGSON1_CLK_H
+
+struct clk_hw *clk_hw_register_pll(struct device *dev,
+				   const char *name,
+				   const char *parent_name,
+				   const struct clk_ops *ops,
+				   unsigned long flags);
+
+#endif /* __LOONGSON1_CLK_H */