drivers/clk/clk-highbank.c - linux - Git at Google

 /*
  * Copyright 2011-2012 Calxeda, Inc.
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU General Public License,
  * version 2, as published by the Free Software Foundation.
  *
  * This program is distributed in the hope it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  * more details.
  *
  * You should have received a copy of the GNU General Public License along with
  * this program.  If not, see <http://www.gnu.org/licenses/>.
  */

 #include <linux/kernel.h>
 #include <linux/slab.h>
 #include <linux/err.h>
 #include <linux/clk-provider.h>
 #include <linux/io.h>
 #include <linux/of.h>
 #include <linux/of_address.h>

 #define HB_PLL_LOCK_500		0x20000000
 #define HB_PLL_LOCK		0x10000000
 #define HB_PLL_DIVF_SHIFT	20
 #define HB_PLL_DIVF_MASK	0x0ff00000
 #define HB_PLL_DIVQ_SHIFT	16
 #define HB_PLL_DIVQ_MASK	0x00070000
 #define HB_PLL_DIVR_SHIFT	8
 #define HB_PLL_DIVR_MASK	0x00001f00
 #define HB_PLL_RANGE_SHIFT	4
 #define HB_PLL_RANGE_MASK	0x00000070
 #define HB_PLL_BYPASS		0x00000008
 #define HB_PLL_RESET		0x00000004
 #define HB_PLL_EXT_BYPASS	0x00000002
 #define HB_PLL_EXT_ENA		0x00000001

 #define HB_PLL_VCO_MIN_FREQ	2133000000
 #define HB_PLL_MAX_FREQ		HB_PLL_VCO_MIN_FREQ
 #define HB_PLL_MIN_FREQ		(HB_PLL_VCO_MIN_FREQ / 64)

 #define HB_A9_BCLK_DIV_MASK	0x00000006
 #define HB_A9_BCLK_DIV_SHIFT	1
 #define HB_A9_PCLK_DIV		0x00000001

 struct hb_clk {
         struct clk_hw	hw;
 	void __iomem	*reg;
 	char *parent_name;
 };
 #define to_hb_clk(p) container_of(p, struct hb_clk, hw)

 static int clk_pll_prepare(struct clk_hw *hwclk)
 	{
 	struct hb_clk *hbclk = to_hb_clk(hwclk);
 	u32 reg;

 	reg = readl(hbclk->reg);
 	reg &= ~HB_PLL_RESET;
 	writel(reg, hbclk->reg);

 	while ((readl(hbclk->reg) & HB_PLL_LOCK) == 0)
 		;
 	while ((readl(hbclk->reg) & HB_PLL_LOCK_500) == 0)
 		;

 	return 0;
 }

 static void clk_pll_unprepare(struct clk_hw *hwclk)
 {
 	struct hb_clk *hbclk = to_hb_clk(hwclk);
 	u32 reg;

 	reg = readl(hbclk->reg);
 	reg |= HB_PLL_RESET;
 	writel(reg, hbclk->reg);
 }

 static int clk_pll_enable(struct clk_hw *hwclk)
 {
 	struct hb_clk *hbclk = to_hb_clk(hwclk);
 	u32 reg;

 	reg = readl(hbclk->reg);
 	reg |= HB_PLL_EXT_ENA;
 	writel(reg, hbclk->reg);

 	return 0;
 }

 static void clk_pll_disable(struct clk_hw *hwclk)
 {
 	struct hb_clk *hbclk = to_hb_clk(hwclk);
 	u32 reg;

 	reg = readl(hbclk->reg);
 	reg &= ~HB_PLL_EXT_ENA;
 	writel(reg, hbclk->reg);
 }

 static unsigned long clk_pll_recalc_rate(struct clk_hw *hwclk,
 					 unsigned long parent_rate)
 {
 	struct hb_clk *hbclk = to_hb_clk(hwclk);
 	unsigned long divf, divq, vco_freq, reg;

 	reg = readl(hbclk->reg);
 	if (reg & HB_PLL_EXT_BYPASS)
 		return parent_rate;

 	divf = (reg & HB_PLL_DIVF_MASK) >> HB_PLL_DIVF_SHIFT;
 	divq = (reg & HB_PLL_DIVQ_MASK) >> HB_PLL_DIVQ_SHIFT;
 	vco_freq = parent_rate * (divf + 1);

 	return vco_freq / (1 << divq);
 }

 static void clk_pll_calc(unsigned long rate, unsigned long ref_freq,
 			u32 *pdivq, u32 *pdivf)
 {
 	u32 divq, divf;
 	unsigned long vco_freq;

 	if (rate < HB_PLL_MIN_FREQ)
 		rate = HB_PLL_MIN_FREQ;
 	if (rate > HB_PLL_MAX_FREQ)
 		rate = HB_PLL_MAX_FREQ;

 	for (divq = 1; divq <= 6; divq++) {
 		if ((rate * (1 << divq)) >= HB_PLL_VCO_MIN_FREQ)
 			break;
 	}

 	vco_freq = rate * (1 << divq);
 	divf = (vco_freq + (ref_freq / 2)) / ref_freq;
 	divf--;

 	*pdivq = divq;
 	*pdivf = divf;
 }

 static long clk_pll_round_rate(struct clk_hw *hwclk, unsigned long rate,
 			       unsigned long *parent_rate)
 {
 	u32 divq, divf;
 	unsigned long ref_freq = *parent_rate;

 	clk_pll_calc(rate, ref_freq, &divq, &divf);

 	return (ref_freq * (divf + 1)) / (1 << divq);
 }

 static int clk_pll_set_rate(struct clk_hw *hwclk, unsigned long rate,
 			    unsigned long parent_rate)
 {
 	struct hb_clk *hbclk = to_hb_clk(hwclk);
 	u32 divq, divf;
 	u32 reg;

 	clk_pll_calc(rate, parent_rate, &divq, &divf);

 	reg = readl(hbclk->reg);
 	if (divf != ((reg & HB_PLL_DIVF_MASK) >> HB_PLL_DIVF_SHIFT)) {
 		/* Need to re-lock PLL, so put it into bypass mode */
 		reg |= HB_PLL_EXT_BYPASS;
 		writel(reg | HB_PLL_EXT_BYPASS, hbclk->reg);

 		writel(reg | HB_PLL_RESET, hbclk->reg);
 		reg &= ~(HB_PLL_DIVF_MASK | HB_PLL_DIVQ_MASK);
 		reg |= (divf << HB_PLL_DIVF_SHIFT) | (divq << HB_PLL_DIVQ_SHIFT);
 		writel(reg | HB_PLL_RESET, hbclk->reg);
 		writel(reg, hbclk->reg);

 		while ((readl(hbclk->reg) & HB_PLL_LOCK) == 0)
 			;
 		while ((readl(hbclk->reg) & HB_PLL_LOCK_500) == 0)
 			;
 		reg |= HB_PLL_EXT_ENA;
 		reg &= ~HB_PLL_EXT_BYPASS;
 	} else {
 		writel(reg | HB_PLL_EXT_BYPASS, hbclk->reg);
 		reg &= ~HB_PLL_DIVQ_MASK;
 		reg |= divq << HB_PLL_DIVQ_SHIFT;
 		writel(reg | HB_PLL_EXT_BYPASS, hbclk->reg);
 	}
 	writel(reg, hbclk->reg);

 	return 0;
 }

 static const struct clk_ops clk_pll_ops = {
 	.prepare = clk_pll_prepare,
 	.unprepare = clk_pll_unprepare,
 	.enable = clk_pll_enable,
 	.disable = clk_pll_disable,
 	.recalc_rate = clk_pll_recalc_rate,
 	.round_rate = clk_pll_round_rate,
 	.set_rate = clk_pll_set_rate,
 };

 static unsigned long clk_cpu_periphclk_recalc_rate(struct clk_hw *hwclk,
 						   unsigned long parent_rate)
 {
 	struct hb_clk *hbclk = to_hb_clk(hwclk);
 	u32 div = (readl(hbclk->reg) & HB_A9_PCLK_DIV) ? 8 : 4;
 	return parent_rate / div;
 }

 static const struct clk_ops a9periphclk_ops = {
 	.recalc_rate = clk_cpu_periphclk_recalc_rate,
 };

 static unsigned long clk_cpu_a9bclk_recalc_rate(struct clk_hw *hwclk,
 						unsigned long parent_rate)
 {
 	struct hb_clk *hbclk = to_hb_clk(hwclk);
 	u32 div = (readl(hbclk->reg) & HB_A9_BCLK_DIV_MASK) >> HB_A9_BCLK_DIV_SHIFT;

 	return parent_rate / (div + 2);
 }

 static const struct clk_ops a9bclk_ops = {
 	.recalc_rate = clk_cpu_a9bclk_recalc_rate,
 };

 static unsigned long clk_periclk_recalc_rate(struct clk_hw *hwclk,
 					     unsigned long parent_rate)
 {
 	struct hb_clk *hbclk = to_hb_clk(hwclk);
 	u32 div;

 	div = readl(hbclk->reg) & 0x1f;
 	div++;
 	div *= 2;

 	return parent_rate / div;
 }

 static long clk_periclk_round_rate(struct clk_hw *hwclk, unsigned long rate,
 				   unsigned long *parent_rate)
 {
 	u32 div;

 	div = *parent_rate / rate;
 	div++;
 	div &= ~0x1;

 	return *parent_rate / div;
 }

 static int clk_periclk_set_rate(struct clk_hw *hwclk, unsigned long rate,
 				unsigned long parent_rate)
 {
 	struct hb_clk *hbclk = to_hb_clk(hwclk);
 	u32 div;

 	div = parent_rate / rate;
 	if (div & 0x1)
 		return -EINVAL;

 	writel(div >> 1, hbclk->reg);
 	return 0;
 }

 static const struct clk_ops periclk_ops = {
 	.recalc_rate = clk_periclk_recalc_rate,
 	.round_rate = clk_periclk_round_rate,
 	.set_rate = clk_periclk_set_rate,
 };

 static void __init hb_clk_init(struct device_node *node, const struct clk_ops *ops, unsigned long clkflags)
 {
 	u32 reg;
 	struct hb_clk *hb_clk;
 	const char *clk_name = node->name;
 	const char *parent_name;
 	struct clk_init_data init;
 	struct device_node *srnp;
 	int rc;

 	rc = of_property_read_u32(node, "reg", &reg);
 	if (WARN_ON(rc))
 		return;

 	hb_clk = kzalloc(sizeof(*hb_clk), GFP_KERNEL);
 	if (WARN_ON(!hb_clk))
 		return;

 	/* Map system registers */
 	srnp = of_find_compatible_node(NULL, NULL, "calxeda,hb-sregs");
 	hb_clk->reg = of_iomap(srnp, 0);
 	of_node_put(srnp);
 	BUG_ON(!hb_clk->reg);
 	hb_clk->reg += reg;

 	of_property_read_string(node, "clock-output-names", &clk_name);

 	init.name = clk_name;
 	init.ops = ops;
 	init.flags = clkflags;
 	parent_name = of_clk_get_parent_name(node, 0);
 	init.parent_names = &parent_name;
 	init.num_parents = 1;

 	hb_clk->hw.init = &init;

 	rc = clk_hw_register(NULL, &hb_clk->hw);
 	if (WARN_ON(rc)) {
 		kfree(hb_clk);
 		return;
 	}
 	of_clk_add_hw_provider(node, of_clk_hw_simple_get, &hb_clk->hw);
 }

 static void __init hb_pll_init(struct device_node *node)
 {
 	hb_clk_init(node, &clk_pll_ops, 0);
 }
 CLK_OF_DECLARE(hb_pll, "calxeda,hb-pll-clock", hb_pll_init);

 static void __init hb_a9periph_init(struct device_node *node)
 {
 	hb_clk_init(node, &a9periphclk_ops, 0);
 }
 CLK_OF_DECLARE(hb_a9periph, "calxeda,hb-a9periph-clock", hb_a9periph_init);

 static void __init hb_a9bus_init(struct device_node *node)
 {
 	hb_clk_init(node, &a9bclk_ops, CLK_IS_CRITICAL);
 }
 CLK_OF_DECLARE(hb_a9bus, "calxeda,hb-a9bus-clock", hb_a9bus_init);

 static void __init hb_emmc_init(struct device_node *node)
 {
 	hb_clk_init(node, &periclk_ops, 0);
 }
 CLK_OF_DECLARE(hb_emmc, "calxeda,hb-emmc-clock", hb_emmc_init);
	/*
	* Copyright 2011-2012 Calxeda, Inc.
	*
	* This program is free software; you can redistribute it and/or modify it
	* under the terms and conditions of the GNU General Public License,
	* version 2, as published by the Free Software Foundation.
	*
	* This program is distributed in the hope it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	* more details.
	*
	* You should have received a copy of the GNU General Public License along with
	* this program. If not, see <http://www.gnu.org/licenses/>.
	*/

	#include <linux/kernel.h>
	#include <linux/slab.h>
	#include <linux/err.h>
	#include <linux/clk-provider.h>
	#include <linux/io.h>
	#include <linux/of.h>
	#include <linux/of_address.h>

	#define HB_PLL_LOCK_500 0x20000000
	#define HB_PLL_LOCK 0x10000000
	#define HB_PLL_DIVF_SHIFT 20
	#define HB_PLL_DIVF_MASK 0x0ff00000
	#define HB_PLL_DIVQ_SHIFT 16
	#define HB_PLL_DIVQ_MASK 0x00070000
	#define HB_PLL_DIVR_SHIFT 8
	#define HB_PLL_DIVR_MASK 0x00001f00
	#define HB_PLL_RANGE_SHIFT 4
	#define HB_PLL_RANGE_MASK 0x00000070
	#define HB_PLL_BYPASS 0x00000008
	#define HB_PLL_RESET 0x00000004
	#define HB_PLL_EXT_BYPASS 0x00000002
	#define HB_PLL_EXT_ENA 0x00000001

	#define HB_PLL_VCO_MIN_FREQ 2133000000
	#define HB_PLL_MAX_FREQ HB_PLL_VCO_MIN_FREQ
	#define HB_PLL_MIN_FREQ (HB_PLL_VCO_MIN_FREQ / 64)

	#define HB_A9_BCLK_DIV_MASK 0x00000006
	#define HB_A9_BCLK_DIV_SHIFT 1
	#define HB_A9_PCLK_DIV 0x00000001

	struct hb_clk {
	struct clk_hw hw;
	void __iomem *reg;
	char *parent_name;
	};
	#define to_hb_clk(p) container_of(p, struct hb_clk, hw)

	static int clk_pll_prepare(struct clk_hw *hwclk)
	{
	struct hb_clk *hbclk = to_hb_clk(hwclk);
	u32 reg;

	reg = readl(hbclk->reg);
	reg &= ~HB_PLL_RESET;
	writel(reg, hbclk->reg);

	while ((readl(hbclk->reg) & HB_PLL_LOCK) == 0)
	;
	while ((readl(hbclk->reg) & HB_PLL_LOCK_500) == 0)
	;

	return 0;
	}

	static void clk_pll_unprepare(struct clk_hw *hwclk)
	{
	struct hb_clk *hbclk = to_hb_clk(hwclk);
	u32 reg;

	reg = readl(hbclk->reg);
	reg \|= HB_PLL_RESET;
	writel(reg, hbclk->reg);
	}

	static int clk_pll_enable(struct clk_hw *hwclk)
	{
	struct hb_clk *hbclk = to_hb_clk(hwclk);
	u32 reg;

	reg = readl(hbclk->reg);
	reg \|= HB_PLL_EXT_ENA;
	writel(reg, hbclk->reg);

	return 0;
	}

	static void clk_pll_disable(struct clk_hw *hwclk)
	{
	struct hb_clk *hbclk = to_hb_clk(hwclk);
	u32 reg;

	reg = readl(hbclk->reg);
	reg &= ~HB_PLL_EXT_ENA;
	writel(reg, hbclk->reg);
	}

	static unsigned long clk_pll_recalc_rate(struct clk_hw *hwclk,
	unsigned long parent_rate)
	{
	struct hb_clk *hbclk = to_hb_clk(hwclk);
	unsigned long divf, divq, vco_freq, reg;

	reg = readl(hbclk->reg);
	if (reg & HB_PLL_EXT_BYPASS)
	return parent_rate;

	divf = (reg & HB_PLL_DIVF_MASK) >> HB_PLL_DIVF_SHIFT;
	divq = (reg & HB_PLL_DIVQ_MASK) >> HB_PLL_DIVQ_SHIFT;
	vco_freq = parent_rate * (divf + 1);

	return vco_freq / (1 << divq);
	}

	static void clk_pll_calc(unsigned long rate, unsigned long ref_freq,
	u32 pdivq, u32 pdivf)
	{
	u32 divq, divf;
	unsigned long vco_freq;

	if (rate < HB_PLL_MIN_FREQ)
	rate = HB_PLL_MIN_FREQ;
	if (rate > HB_PLL_MAX_FREQ)
	rate = HB_PLL_MAX_FREQ;

	for (divq = 1; divq <= 6; divq++) {
	if ((rate * (1 << divq)) >= HB_PLL_VCO_MIN_FREQ)
	break;
	}

	vco_freq = rate * (1 << divq);
	divf = (vco_freq + (ref_freq / 2)) / ref_freq;
	divf--;

	*pdivq = divq;
	*pdivf = divf;
	}

	static long clk_pll_round_rate(struct clk_hw *hwclk, unsigned long rate,
	unsigned long *parent_rate)
	{
	u32 divq, divf;
	unsigned long ref_freq = *parent_rate;

	clk_pll_calc(rate, ref_freq, &divq, &divf);

	return (ref_freq * (divf + 1)) / (1 << divq);
	}

	static int clk_pll_set_rate(struct clk_hw *hwclk, unsigned long rate,
	unsigned long parent_rate)
	{
	struct hb_clk *hbclk = to_hb_clk(hwclk);
	u32 divq, divf;
	u32 reg;

	clk_pll_calc(rate, parent_rate, &divq, &divf);

	reg = readl(hbclk->reg);
	if (divf != ((reg & HB_PLL_DIVF_MASK) >> HB_PLL_DIVF_SHIFT)) {
	/* Need to re-lock PLL, so put it into bypass mode */
	reg \|= HB_PLL_EXT_BYPASS;
	writel(reg \| HB_PLL_EXT_BYPASS, hbclk->reg);

	writel(reg \| HB_PLL_RESET, hbclk->reg);
	reg &= ~(HB_PLL_DIVF_MASK \| HB_PLL_DIVQ_MASK);
	reg \|= (divf << HB_PLL_DIVF_SHIFT) \| (divq << HB_PLL_DIVQ_SHIFT);
	writel(reg \| HB_PLL_RESET, hbclk->reg);
	writel(reg, hbclk->reg);

	while ((readl(hbclk->reg) & HB_PLL_LOCK) == 0)
	;
	while ((readl(hbclk->reg) & HB_PLL_LOCK_500) == 0)
	;
	reg \|= HB_PLL_EXT_ENA;
	reg &= ~HB_PLL_EXT_BYPASS;
	} else {
	writel(reg \| HB_PLL_EXT_BYPASS, hbclk->reg);
	reg &= ~HB_PLL_DIVQ_MASK;
	reg \|= divq << HB_PLL_DIVQ_SHIFT;
	writel(reg \| HB_PLL_EXT_BYPASS, hbclk->reg);
	}
	writel(reg, hbclk->reg);

	return 0;
	}

	static const struct clk_ops clk_pll_ops = {
	.prepare = clk_pll_prepare,
	.unprepare = clk_pll_unprepare,
	.enable = clk_pll_enable,
	.disable = clk_pll_disable,
	.recalc_rate = clk_pll_recalc_rate,
	.round_rate = clk_pll_round_rate,
	.set_rate = clk_pll_set_rate,
	};

	static unsigned long clk_cpu_periphclk_recalc_rate(struct clk_hw *hwclk,
	unsigned long parent_rate)
	{
	struct hb_clk *hbclk = to_hb_clk(hwclk);
	u32 div = (readl(hbclk->reg) & HB_A9_PCLK_DIV) ? 8 : 4;
	return parent_rate / div;
	}

	static const struct clk_ops a9periphclk_ops = {
	.recalc_rate = clk_cpu_periphclk_recalc_rate,
	};

	static unsigned long clk_cpu_a9bclk_recalc_rate(struct clk_hw *hwclk,
	unsigned long parent_rate)
	{
	struct hb_clk *hbclk = to_hb_clk(hwclk);
	u32 div = (readl(hbclk->reg) & HB_A9_BCLK_DIV_MASK) >> HB_A9_BCLK_DIV_SHIFT;

	return parent_rate / (div + 2);
	}

	static const struct clk_ops a9bclk_ops = {
	.recalc_rate = clk_cpu_a9bclk_recalc_rate,
	};

	static unsigned long clk_periclk_recalc_rate(struct clk_hw *hwclk,
	unsigned long parent_rate)
	{
	struct hb_clk *hbclk = to_hb_clk(hwclk);
	u32 div;

	div = readl(hbclk->reg) & 0x1f;
	div++;
	div *= 2;

	return parent_rate / div;
	}

	static long clk_periclk_round_rate(struct clk_hw *hwclk, unsigned long rate,
	unsigned long *parent_rate)
	{
	u32 div;

	div = *parent_rate / rate;
	div++;
	div &= ~0x1;

	return *parent_rate / div;
	}

	static int clk_periclk_set_rate(struct clk_hw *hwclk, unsigned long rate,
	unsigned long parent_rate)
	{
	struct hb_clk *hbclk = to_hb_clk(hwclk);
	u32 div;

	div = parent_rate / rate;
	if (div & 0x1)
	return -EINVAL;

	writel(div >> 1, hbclk->reg);
	return 0;
	}

	static const struct clk_ops periclk_ops = {
	.recalc_rate = clk_periclk_recalc_rate,
	.round_rate = clk_periclk_round_rate,
	.set_rate = clk_periclk_set_rate,
	};

	static void __init hb_clk_init(struct device_node node, const struct clk_ops ops, unsigned long clkflags)
	{
	u32 reg;
	struct hb_clk *hb_clk;
	const char *clk_name = node->name;
	const char *parent_name;
	struct clk_init_data init;
	struct device_node *srnp;
	int rc;

	rc = of_property_read_u32(node, "reg", &reg);
	if (WARN_ON(rc))
	return;

	hb_clk = kzalloc(sizeof(*hb_clk), GFP_KERNEL);
	if (WARN_ON(!hb_clk))
	return;

	/* Map system registers */
	srnp = of_find_compatible_node(NULL, NULL, "calxeda,hb-sregs");
	hb_clk->reg = of_iomap(srnp, 0);
	of_node_put(srnp);
	BUG_ON(!hb_clk->reg);
	hb_clk->reg += reg;

	of_property_read_string(node, "clock-output-names", &clk_name);

	init.name = clk_name;
	init.ops = ops;
	init.flags = clkflags;
	parent_name = of_clk_get_parent_name(node, 0);
	init.parent_names = &parent_name;
	init.num_parents = 1;

	hb_clk->hw.init = &init;

	rc = clk_hw_register(NULL, &hb_clk->hw);
	if (WARN_ON(rc)) {
	kfree(hb_clk);
	return;
	}
	of_clk_add_hw_provider(node, of_clk_hw_simple_get, &hb_clk->hw);
	}

	static void __init hb_pll_init(struct device_node *node)
	{
	hb_clk_init(node, &clk_pll_ops, 0);
	}
	CLK_OF_DECLARE(hb_pll, "calxeda,hb-pll-clock", hb_pll_init);

	static void __init hb_a9periph_init(struct device_node *node)
	{
	hb_clk_init(node, &a9periphclk_ops, 0);
	}
	CLK_OF_DECLARE(hb_a9periph, "calxeda,hb-a9periph-clock", hb_a9periph_init);

	static void __init hb_a9bus_init(struct device_node *node)
	{
	hb_clk_init(node, &a9bclk_ops, CLK_IS_CRITICAL);
	}
	CLK_OF_DECLARE(hb_a9bus, "calxeda,hb-a9bus-clock", hb_a9bus_init);

	static void __init hb_emmc_init(struct device_node *node)
	{
	hb_clk_init(node, &periclk_ops, 0);
	}
	CLK_OF_DECLARE(hb_emmc, "calxeda,hb-emmc-clock", hb_emmc_init);