drivers/clk/mvebu/common.c - kernel/msm-4.9 - Gitiles

 /*
  * Marvell EBU SoC common clock handling
  *
  * Copyright (C) 2012 Marvell
  *
  * Gregory CLEMENT <gregory.clement@free-electrons.com>
  * Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
  * Andrew Lunn <andrew@lunn.ch>
  *
  * This file is licensed under the terms of the GNU General Public
  * License version 2.  This program is licensed "as is" without any
  * warranty of any kind, whether express or implied.
  */

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

 #include "common.h"

 /*
  * Core Clocks
  */

 #define SSCG_CONF_MODE(reg)	(((reg) >> 16) & 0x3)
 #define SSCG_SPREAD_DOWN	0x0
 #define SSCG_SPREAD_UP		0x1
 #define SSCG_SPREAD_CENTRAL	0x2
 #define SSCG_CONF_LOW(reg)	(((reg) >> 8) & 0xFF)
 #define SSCG_CONF_HIGH(reg)	((reg) & 0xFF)

 static struct clk_onecell_data clk_data;

 /*
  * This function can be used by the Kirkwood, the Armada 370, the
  * Armada XP and the Armada 375 SoC. The name of the function was
  * chosen following the dt convention: using the first known SoC
  * compatible with it.
  */
 u32 kirkwood_fix_sscg_deviation(u32 system_clk)
 {
 	struct device_node *sscg_np = NULL;
 	void __iomem *sscg_map;
 	u32 sscg_reg;
 	s32 low_bound, high_bound;
 	u64 freq_swing_half;

 	sscg_np = of_find_node_by_name(NULL, "sscg");
 	if (sscg_np == NULL) {
 		pr_err("cannot get SSCG register node\n");
 		return system_clk;
 	}

 	sscg_map = of_iomap(sscg_np, 0);
 	if (sscg_map == NULL) {
 		pr_err("cannot map SSCG register\n");
 		goto out;
 	}

 	sscg_reg = readl(sscg_map);
 	high_bound = SSCG_CONF_HIGH(sscg_reg);
 	low_bound = SSCG_CONF_LOW(sscg_reg);

 	if ((high_bound - low_bound) <= 0)
 		goto out;
 	/*
 	 * From Marvell engineer we got the following formula (when
 	 * this code was written, the datasheet was erroneous)
 	 * Spread percentage = 1/96 * (H - L) / H
 	 * H = SSCG_High_Boundary
 	 * L = SSCG_Low_Boundary
 	 *
 	 * As the deviation is half of spread then it lead to the
 	 * following formula in the code.
 	 *
 	 * To avoid an overflow and not lose any significant digit in
 	 * the same time we have to use a 64 bit integer.
 	 */

 	freq_swing_half = (((u64)high_bound - (u64)low_bound)
 			* (u64)system_clk);
 	do_div(freq_swing_half, (2 * 96 * high_bound));

 	switch (SSCG_CONF_MODE(sscg_reg)) {
 	case SSCG_SPREAD_DOWN:
 		system_clk -= freq_swing_half;
 		break;
 	case SSCG_SPREAD_UP:
 		system_clk += freq_swing_half;
 		break;
 	case SSCG_SPREAD_CENTRAL:
 	default:
 		break;
 	}

 	iounmap(sscg_map);

 out:
 	of_node_put(sscg_np);

 	return system_clk;
 }

 void __init mvebu_coreclk_setup(struct device_node *np,
 				const struct coreclk_soc_desc *desc)
 {
 	const char *tclk_name = "tclk";
 	const char *cpuclk_name = "cpuclk";
 	void __iomem *base;
 	unsigned long rate;
 	int n;

 	base = of_iomap(np, 0);
 	if (WARN_ON(!base))
 		return;

 	/* Allocate struct for TCLK, cpu clk, and core ratio clocks */
 	clk_data.clk_num = 2 + desc->num_ratios;

 	/* One more clock for the optional refclk */
 	if (desc->get_refclk_freq)
 		clk_data.clk_num += 1;

 	clk_data.clks = kzalloc(clk_data.clk_num * sizeof(struct clk *),
 				GFP_KERNEL);
 	if (WARN_ON(!clk_data.clks)) {
 		iounmap(base);
 		return;
 	}

 	/* Register TCLK */
 	of_property_read_string_index(np, "clock-output-names", 0,
 				      &tclk_name);
 	rate = desc->get_tclk_freq(base);
 	clk_data.clks[0] = clk_register_fixed_rate(NULL, tclk_name, NULL,
 						   CLK_IS_ROOT, rate);
 	WARN_ON(IS_ERR(clk_data.clks[0]));

 	/* Register CPU clock */
 	of_property_read_string_index(np, "clock-output-names", 1,
 				      &cpuclk_name);
 	rate = desc->get_cpu_freq(base);

 	if (desc->is_sscg_enabled && desc->fix_sscg_deviation
 		&& desc->is_sscg_enabled(base))
 		rate = desc->fix_sscg_deviation(rate);

 	clk_data.clks[1] = clk_register_fixed_rate(NULL, cpuclk_name, NULL,
 						   CLK_IS_ROOT, rate);
 	WARN_ON(IS_ERR(clk_data.clks[1]));

 	/* Register fixed-factor clocks derived from CPU clock */
 	for (n = 0; n < desc->num_ratios; n++) {
 		const char *rclk_name = desc->ratios[n].name;
 		int mult, div;

 		of_property_read_string_index(np, "clock-output-names",
 					      2+n, &rclk_name);
 		desc->get_clk_ratio(base, desc->ratios[n].id, &mult, &div);
 		clk_data.clks[2+n] = clk_register_fixed_factor(NULL, rclk_name,
 				       cpuclk_name, 0, mult, div);
 		WARN_ON(IS_ERR(clk_data.clks[2+n]));
 	};

 	/* Register optional refclk */
 	if (desc->get_refclk_freq) {
 		const char *name = "refclk";
 		of_property_read_string_index(np, "clock-output-names",
 					      2 + desc->num_ratios, &name);
 		rate = desc->get_refclk_freq(base);
 		clk_data.clks[2 + desc->num_ratios] =
 			clk_register_fixed_rate(NULL, name, NULL,
 						CLK_IS_ROOT, rate);
 		WARN_ON(IS_ERR(clk_data.clks[2 + desc->num_ratios]));
 	}

 	/* SAR register isn't needed anymore */
 	iounmap(base);

 	of_clk_add_provider(np, of_clk_src_onecell_get, &clk_data);
 }

 /*
  * Clock Gating Control
  */

 DEFINE_SPINLOCK(ctrl_gating_lock);

 struct clk_gating_ctrl {
 	spinlock_t *lock;
 	struct clk **gates;
 	int num_gates;
 	void __iomem *base;
 	u32 saved_reg;
 };

 #define to_clk_gate(_hw) container_of(_hw, struct clk_gate, hw)

 static struct clk_gating_ctrl *ctrl;

 static struct clk *clk_gating_get_src(
 	struct of_phandle_args *clkspec, void *data)
 {
 	int n;

 	if (clkspec->args_count < 1)
 		return ERR_PTR(-EINVAL);

 	for (n = 0; n < ctrl->num_gates; n++) {
 		struct clk_gate *gate =
 			to_clk_gate(__clk_get_hw(ctrl->gates[n]));
 		if (clkspec->args[0] == gate->bit_idx)
 			return ctrl->gates[n];
 	}
 	return ERR_PTR(-ENODEV);
 }

 static int mvebu_clk_gating_suspend(void)
 {
 	ctrl->saved_reg = readl(ctrl->base);
 	return 0;
 }

 static void mvebu_clk_gating_resume(void)
 {
 	writel(ctrl->saved_reg, ctrl->base);
 }

 static struct syscore_ops clk_gate_syscore_ops = {
 	.suspend = mvebu_clk_gating_suspend,
 	.resume = mvebu_clk_gating_resume,
 };

 void __init mvebu_clk_gating_setup(struct device_node *np,
 				   const struct clk_gating_soc_desc *desc)
 {
 	struct clk *clk;
 	void __iomem *base;
 	const char *default_parent = NULL;
 	int n;

 	if (ctrl) {
 		pr_err("mvebu-clk-gating: cannot instantiate more than one gatable clock device\n");
 		return;
 	}

 	base = of_iomap(np, 0);
 	if (WARN_ON(!base))
 		return;

 	clk = of_clk_get(np, 0);
 	if (!IS_ERR(clk)) {
 		default_parent = __clk_get_name(clk);
 		clk_put(clk);
 	}

 	ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
 	if (WARN_ON(!ctrl))
 		goto ctrl_out;

 	/* lock must already be initialized */
 	ctrl->lock = &ctrl_gating_lock;

 	ctrl->base = base;

 	/* Count, allocate, and register clock gates */
 	for (n = 0; desc[n].name;)
 		n++;

 	ctrl->num_gates = n;
 	ctrl->gates = kzalloc(ctrl->num_gates * sizeof(struct clk *),
 			      GFP_KERNEL);
 	if (WARN_ON(!ctrl->gates))
 		goto gates_out;

 	for (n = 0; n < ctrl->num_gates; n++) {
 		const char *parent =
 			(desc[n].parent) ? desc[n].parent : default_parent;
 		ctrl->gates[n] = clk_register_gate(NULL, desc[n].name, parent,
 					desc[n].flags, base, desc[n].bit_idx,
 					0, ctrl->lock);
 		WARN_ON(IS_ERR(ctrl->gates[n]));
 	}

 	of_clk_add_provider(np, clk_gating_get_src, ctrl);

 	register_syscore_ops(&clk_gate_syscore_ops);

 	return;
 gates_out:
 	kfree(ctrl);
 ctrl_out:
 	iounmap(base);
 }
	/*
	* Marvell EBU SoC common clock handling
	*
	* Copyright (C) 2012 Marvell
	*
	* Gregory CLEMENT <gregory.clement@free-electrons.com>
	* Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
	* Andrew Lunn <andrew@lunn.ch>
	*
	* This file is licensed under the terms of the GNU General Public
	* License version 2. This program is licensed "as is" without any
	* warranty of any kind, whether express or implied.
	*/

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

	#include "common.h"

	/*
	* Core Clocks
	*/

	#define SSCG_CONF_MODE(reg) (((reg) >> 16) & 0x3)
	#define SSCG_SPREAD_DOWN 0x0
	#define SSCG_SPREAD_UP 0x1
	#define SSCG_SPREAD_CENTRAL 0x2
	#define SSCG_CONF_LOW(reg) (((reg) >> 8) & 0xFF)
	#define SSCG_CONF_HIGH(reg) ((reg) & 0xFF)

	static struct clk_onecell_data clk_data;

	/*
	* This function can be used by the Kirkwood, the Armada 370, the
	* Armada XP and the Armada 375 SoC. The name of the function was
	* chosen following the dt convention: using the first known SoC
	* compatible with it.
	*/
	u32 kirkwood_fix_sscg_deviation(u32 system_clk)
	{
	struct device_node *sscg_np = NULL;
	void __iomem *sscg_map;
	u32 sscg_reg;
	s32 low_bound, high_bound;
	u64 freq_swing_half;

	sscg_np = of_find_node_by_name(NULL, "sscg");
	if (sscg_np == NULL) {
	pr_err("cannot get SSCG register node\n");
	return system_clk;
	}

	sscg_map = of_iomap(sscg_np, 0);
	if (sscg_map == NULL) {
	pr_err("cannot map SSCG register\n");
	goto out;
	}

	sscg_reg = readl(sscg_map);
	high_bound = SSCG_CONF_HIGH(sscg_reg);
	low_bound = SSCG_CONF_LOW(sscg_reg);

	if ((high_bound - low_bound) <= 0)
	goto out;
	/*
	* From Marvell engineer we got the following formula (when
	* this code was written, the datasheet was erroneous)
	* Spread percentage = 1/96 * (H - L) / H
	* H = SSCG_High_Boundary
	* L = SSCG_Low_Boundary
	*
	* As the deviation is half of spread then it lead to the
	* following formula in the code.
	*
	* To avoid an overflow and not lose any significant digit in
	* the same time we have to use a 64 bit integer.
	*/

	freq_swing_half = (((u64)high_bound - (u64)low_bound)
	* (u64)system_clk);
	do_div(freq_swing_half, (2 * 96 * high_bound));

	switch (SSCG_CONF_MODE(sscg_reg)) {
	case SSCG_SPREAD_DOWN:
	system_clk -= freq_swing_half;
	break;
	case SSCG_SPREAD_UP:
	system_clk += freq_swing_half;
	break;
	case SSCG_SPREAD_CENTRAL:
	default:
	break;
	}

	iounmap(sscg_map);

	out:
	of_node_put(sscg_np);

	return system_clk;
	}

	void __init mvebu_coreclk_setup(struct device_node *np,
	const struct coreclk_soc_desc *desc)
	{
	const char *tclk_name = "tclk";
	const char *cpuclk_name = "cpuclk";
	void __iomem *base;
	unsigned long rate;
	int n;

	base = of_iomap(np, 0);
	if (WARN_ON(!base))
	return;

	/* Allocate struct for TCLK, cpu clk, and core ratio clocks */
	clk_data.clk_num = 2 + desc->num_ratios;

	/* One more clock for the optional refclk */
	if (desc->get_refclk_freq)
	clk_data.clk_num += 1;

	clk_data.clks = kzalloc(clk_data.clk_num * sizeof(struct clk *),
	GFP_KERNEL);
	if (WARN_ON(!clk_data.clks)) {
	iounmap(base);
	return;
	}

	/* Register TCLK */
	of_property_read_string_index(np, "clock-output-names", 0,
	&tclk_name);
	rate = desc->get_tclk_freq(base);
	clk_data.clks[0] = clk_register_fixed_rate(NULL, tclk_name, NULL,
	CLK_IS_ROOT, rate);
	WARN_ON(IS_ERR(clk_data.clks[0]));

	/* Register CPU clock */
	of_property_read_string_index(np, "clock-output-names", 1,
	&cpuclk_name);
	rate = desc->get_cpu_freq(base);

	if (desc->is_sscg_enabled && desc->fix_sscg_deviation
	&& desc->is_sscg_enabled(base))
	rate = desc->fix_sscg_deviation(rate);

	clk_data.clks[1] = clk_register_fixed_rate(NULL, cpuclk_name, NULL,
	CLK_IS_ROOT, rate);
	WARN_ON(IS_ERR(clk_data.clks[1]));

	/* Register fixed-factor clocks derived from CPU clock */
	for (n = 0; n < desc->num_ratios; n++) {
	const char *rclk_name = desc->ratios[n].name;
	int mult, div;

	of_property_read_string_index(np, "clock-output-names",
	2+n, &rclk_name);
	desc->get_clk_ratio(base, desc->ratios[n].id, &mult, &div);
	clk_data.clks[2+n] = clk_register_fixed_factor(NULL, rclk_name,
	cpuclk_name, 0, mult, div);
	WARN_ON(IS_ERR(clk_data.clks[2+n]));
	};

	/* Register optional refclk */
	if (desc->get_refclk_freq) {
	const char *name = "refclk";
	of_property_read_string_index(np, "clock-output-names",
	2 + desc->num_ratios, &name);
	rate = desc->get_refclk_freq(base);
	clk_data.clks[2 + desc->num_ratios] =
	clk_register_fixed_rate(NULL, name, NULL,
	CLK_IS_ROOT, rate);
	WARN_ON(IS_ERR(clk_data.clks[2 + desc->num_ratios]));
	}

	/* SAR register isn't needed anymore */
	iounmap(base);

	of_clk_add_provider(np, of_clk_src_onecell_get, &clk_data);
	}

	/*
	* Clock Gating Control
	*/

	DEFINE_SPINLOCK(ctrl_gating_lock);

	struct clk_gating_ctrl {
	spinlock_t *lock;
	struct clk **gates;
	int num_gates;
	void __iomem *base;
	u32 saved_reg;
	};

	#define to_clk_gate(_hw) container_of(_hw, struct clk_gate, hw)

	static struct clk_gating_ctrl *ctrl;

	static struct clk *clk_gating_get_src(
	struct of_phandle_args clkspec, void data)
	{
	int n;

	if (clkspec->args_count < 1)
	return ERR_PTR(-EINVAL);

	for (n = 0; n < ctrl->num_gates; n++) {
	struct clk_gate *gate =
	to_clk_gate(__clk_get_hw(ctrl->gates[n]));
	if (clkspec->args[0] == gate->bit_idx)
	return ctrl->gates[n];
	}
	return ERR_PTR(-ENODEV);
	}

	static int mvebu_clk_gating_suspend(void)
	{
	ctrl->saved_reg = readl(ctrl->base);
	return 0;
	}

	static void mvebu_clk_gating_resume(void)
	{
	writel(ctrl->saved_reg, ctrl->base);
	}

	static struct syscore_ops clk_gate_syscore_ops = {
	.suspend = mvebu_clk_gating_suspend,
	.resume = mvebu_clk_gating_resume,
	};

	void __init mvebu_clk_gating_setup(struct device_node *np,
	const struct clk_gating_soc_desc *desc)
	{
	struct clk *clk;
	void __iomem *base;
	const char *default_parent = NULL;
	int n;

	if (ctrl) {
	pr_err("mvebu-clk-gating: cannot instantiate more than one gatable clock device\n");
	return;
	}

	base = of_iomap(np, 0);
	if (WARN_ON(!base))
	return;

	clk = of_clk_get(np, 0);
	if (!IS_ERR(clk)) {
	default_parent = __clk_get_name(clk);
	clk_put(clk);
	}

	ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
	if (WARN_ON(!ctrl))
	goto ctrl_out;

	/* lock must already be initialized */
	ctrl->lock = &ctrl_gating_lock;

	ctrl->base = base;

	/* Count, allocate, and register clock gates */
	for (n = 0; desc[n].name;)
	n++;

	ctrl->num_gates = n;
	ctrl->gates = kzalloc(ctrl->num_gates * sizeof(struct clk *),
	GFP_KERNEL);
	if (WARN_ON(!ctrl->gates))
	goto gates_out;

	for (n = 0; n < ctrl->num_gates; n++) {
	const char *parent =
	(desc[n].parent) ? desc[n].parent : default_parent;
	ctrl->gates[n] = clk_register_gate(NULL, desc[n].name, parent,
	desc[n].flags, base, desc[n].bit_idx,
	0, ctrl->lock);
	WARN_ON(IS_ERR(ctrl->gates[n]));
	}

	of_clk_add_provider(np, clk_gating_get_src, ctrl);

	register_syscore_ops(&clk_gate_syscore_ops);

	return;
	gates_out:
	kfree(ctrl);
	ctrl_out:
	iounmap(base);
	}