[mirror_ubuntu-artful-kernel.git] / drivers / clk / mvebu / common.c

/*
 * 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/clk.h>
#include <linux/clkdev.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;
	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]));
	};

	/* 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);
}
Commit	Line	Data
a4518409 SH	1	/*
	2	* Marvell EBU SoC common clock handling
	3	*
	4	* Copyright (C) 2012 Marvell
	5	*
	6	* Gregory CLEMENT <gregory.clement@free-electrons.com>
	7	* Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
	8	* Andrew Lunn <andrew@lunn.ch>
	9	*
	10	* This file is licensed under the terms of the GNU General Public
	11	* License version 2. This program is licensed "as is" without any
	12	* warranty of any kind, whether express or implied.
	13	*/
	14
	15	#include <linux/kernel.h>
	16	#include <linux/clk.h>
	17	#include <linux/clkdev.h>
	18	#include <linux/clk-provider.h>
	19	#include <linux/io.h>
	20	#include <linux/of.h>
	21	#include <linux/of_address.h>
f5710531	22	#include <linux/syscore_ops.h>
a4518409 SH	23
	24	#include "common.h"
	25
	26	/*
	27	* Core Clocks
	28	*/
	29
15917b16 GC	30	#define SSCG_CONF_MODE(reg) (((reg) >> 16) & 0x3)
	31	#define SSCG_SPREAD_DOWN 0x0
	32	#define SSCG_SPREAD_UP 0x1
	33	#define SSCG_SPREAD_CENTRAL 0x2
	34	#define SSCG_CONF_LOW(reg) (((reg) >> 8) & 0xFF)
	35	#define SSCG_CONF_HIGH(reg) ((reg) & 0xFF)
	36
a4518409 SH	37	static struct clk_onecell_data clk_data;
a4518409 SH	38
15917b16 GC	39	/*
	40	* This function can be used by the Kirkwood, the Armada 370, the
	41	* Armada XP and the Armada 375 SoC. The name of the function was
	42	* chosen following the dt convention: using the first known SoC
	43	* compatible with it.
	44	*/
5f093ee7	45	u32 kirkwood_fix_sscg_deviation(u32 system_clk)
15917b16 GC	46	{
	47	struct device_node *sscg_np = NULL;
	48	void __iomem *sscg_map;
	49	u32 sscg_reg;
	50	s32 low_bound, high_bound;
	51	u64 freq_swing_half;
	52
5f093ee7	53	sscg_np = of_find_node_by_name(NULL, "sscg");
15917b16 GC	54	if (sscg_np == NULL) {
	55	pr_err("cannot get SSCG register node\n");
	56	return system_clk;
	57	}
	58
	59	sscg_map = of_iomap(sscg_np, 0);
	60	if (sscg_map == NULL) {
	61	pr_err("cannot map SSCG register\n");
	62	goto out;
	63	}
	64
	65	sscg_reg = readl(sscg_map);
	66	high_bound = SSCG_CONF_HIGH(sscg_reg);
	67	low_bound = SSCG_CONF_LOW(sscg_reg);
	68
	69	if ((high_bound - low_bound) <= 0)
	70	goto out;
	71	/*
	72	* From Marvell engineer we got the following formula (when
	73	* this code was written, the datasheet was erroneous)
	74	* Spread percentage = 1/96 * (H - L) / H
	75	* H = SSCG_High_Boundary
	76	* L = SSCG_Low_Boundary
	77	*
	78	* As the deviation is half of spread then it lead to the
	79	* following formula in the code.
	80	*
	81	* To avoid an overflow and not lose any significant digit in
	82	* the same time we have to use a 64 bit integer.
	83	*/
	84
	85	freq_swing_half = (((u64)high_bound - (u64)low_bound)
	86	* (u64)system_clk);
	87	do_div(freq_swing_half, (2 * 96 * high_bound));
	88
	89	switch (SSCG_CONF_MODE(sscg_reg)) {
	90	case SSCG_SPREAD_DOWN:
	91	system_clk -= freq_swing_half;
	92	break;
	93	case SSCG_SPREAD_UP:
	94	system_clk += freq_swing_half;
	95	break;
	96	case SSCG_SPREAD_CENTRAL:
	97	default:
	98	break;
	99	}
	100
	101	iounmap(sscg_map);
	102
	103	out:
	104	of_node_put(sscg_np);
	105
	106	return system_clk;
	107	}
	108
a4518409 SH	109	void __init mvebu_coreclk_setup(struct device_node *np,
	110	const struct coreclk_soc_desc *desc)
	111	{
	112	const char *tclk_name = "tclk";
	113	const char *cpuclk_name = "cpuclk";
	114	void __iomem *base;
	115	unsigned long rate;
	116	int n;
	117
	118	base = of_iomap(np, 0);
	119	if (WARN_ON(!base))
	120	return;
	121
	122	/* Allocate struct for TCLK, cpu clk, and core ratio clocks */
	123	clk_data.clk_num = 2 + desc->num_ratios;
	124	clk_data.clks = kzalloc(clk_data.clk_num * sizeof(struct clk *),
	125	GFP_KERNEL);
f98d007d JZ	126	if (WARN_ON(!clk_data.clks)) {
f98d007d JZ	127	iounmap(base);
a4518409	128	return;
f98d007d	129	}
a4518409 SH	130
	131	/* Register TCLK */
	132	of_property_read_string_index(np, "clock-output-names", 0,
	133	&tclk_name);
	134	rate = desc->get_tclk_freq(base);
	135	clk_data.clks[0] = clk_register_fixed_rate(NULL, tclk_name, NULL,
	136	CLK_IS_ROOT, rate);
	137	WARN_ON(IS_ERR(clk_data.clks[0]));
	138
	139	/* Register CPU clock */
	140	of_property_read_string_index(np, "clock-output-names", 1,
	141	&cpuclk_name);
	142	rate = desc->get_cpu_freq(base);
15917b16 GC	143
	144	if (desc->is_sscg_enabled && desc->fix_sscg_deviation
	145	&& desc->is_sscg_enabled(base))
5f093ee7	146	rate = desc->fix_sscg_deviation(rate);
15917b16	147
a4518409 SH	148	clk_data.clks[1] = clk_register_fixed_rate(NULL, cpuclk_name, NULL,
	149	CLK_IS_ROOT, rate);
	150	WARN_ON(IS_ERR(clk_data.clks[1]));
	151
	152	/* Register fixed-factor clocks derived from CPU clock */
	153	for (n = 0; n < desc->num_ratios; n++) {
	154	const char *rclk_name = desc->ratios[n].name;
	155	int mult, div;
	156
	157	of_property_read_string_index(np, "clock-output-names",
	158	2+n, &rclk_name);
	159	desc->get_clk_ratio(base, desc->ratios[n].id, &mult, &div);
	160	clk_data.clks[2+n] = clk_register_fixed_factor(NULL, rclk_name,
	161	cpuclk_name, 0, mult, div);
	162	WARN_ON(IS_ERR(clk_data.clks[2+n]));
	163	};
	164
	165	/* SAR register isn't needed anymore */
	166	iounmap(base);
	167
	168	of_clk_add_provider(np, of_clk_src_onecell_get, &clk_data);
	169	}
	170
	171	/*
	172	* Clock Gating Control
	173	*/
	174
87e39216 MT	175	DEFINE_SPINLOCK(ctrl_gating_lock);
87e39216 MT	176
a4518409	177	struct clk_gating_ctrl {
87e39216	178	spinlock_t *lock;
a4518409 SH	179	struct clk **gates;
a4518409 SH	180	int num_gates;
f5710531 TP	181	void __iomem *base;
f5710531 TP	182	u32 saved_reg;
a4518409 SH	183	};
	184
	185	#define to_clk_gate(_hw) container_of(_hw, struct clk_gate, hw)
	186
f5710531 TP	187	static struct clk_gating_ctrl *ctrl;
f5710531 TP	188
a4518409 SH	189	static struct clk *clk_gating_get_src(
	190	struct of_phandle_args clkspec, void data)
	191	{
a4518409 SH	192	int n;
	193
	194	if (clkspec->args_count < 1)
	195	return ERR_PTR(-EINVAL);
	196
	197	for (n = 0; n < ctrl->num_gates; n++) {
	198	struct clk_gate *gate =
	199	to_clk_gate(__clk_get_hw(ctrl->gates[n]));
	200	if (clkspec->args[0] == gate->bit_idx)
	201	return ctrl->gates[n];
	202	}
	203	return ERR_PTR(-ENODEV);
	204	}
	205
f5710531 TP	206	static int mvebu_clk_gating_suspend(void)
	207	{
	208	ctrl->saved_reg = readl(ctrl->base);
	209	return 0;
	210	}
	211
	212	static void mvebu_clk_gating_resume(void)
	213	{
	214	writel(ctrl->saved_reg, ctrl->base);
	215	}
	216
	217	static struct syscore_ops clk_gate_syscore_ops = {
	218	.suspend = mvebu_clk_gating_suspend,
	219	.resume = mvebu_clk_gating_resume,
	220	};
	221
a4518409 SH	222	void __init mvebu_clk_gating_setup(struct device_node *np,
	223	const struct clk_gating_soc_desc *desc)
	224	{
a4518409 SH	225	struct clk *clk;
	226	void __iomem *base;
	227	const char *default_parent = NULL;
	228	int n;
	229
f5710531 TP	230	if (ctrl) {
	231	pr_err("mvebu-clk-gating: cannot instantiate more than one gatable clock device\n");
	232	return;
	233	}
	234
a4518409 SH	235	base = of_iomap(np, 0);
	236	if (WARN_ON(!base))
	237	return;
	238
	239	clk = of_clk_get(np, 0);
	240	if (!IS_ERR(clk)) {
	241	default_parent = __clk_get_name(clk);
	242	clk_put(clk);
	243	}
	244
	245	ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
	246	if (WARN_ON(!ctrl))
f98d007d	247	goto ctrl_out;
a4518409	248
87e39216 MT	249	/* lock must already be initialized */
87e39216 MT	250	ctrl->lock = &ctrl_gating_lock;
a4518409	251
f5710531 TP	252	ctrl->base = base;
f5710531 TP	253
a4518409 SH	254	/* Count, allocate, and register clock gates */
	255	for (n = 0; desc[n].name;)
	256	n++;
	257
	258	ctrl->num_gates = n;
	259	ctrl->gates = kzalloc(ctrl->num_gates * sizeof(struct clk *),
	260	GFP_KERNEL);
f98d007d JZ	261	if (WARN_ON(!ctrl->gates))
f98d007d JZ	262	goto gates_out;
a4518409 SH	263
	264	for (n = 0; n < ctrl->num_gates; n++) {
	265	const char *parent =
	266	(desc[n].parent) ? desc[n].parent : default_parent;
	267	ctrl->gates[n] = clk_register_gate(NULL, desc[n].name, parent,
	268	desc[n].flags, base, desc[n].bit_idx,
87e39216	269	0, ctrl->lock);
a4518409 SH	270	WARN_ON(IS_ERR(ctrl->gates[n]));
	271	}
	272
	273	of_clk_add_provider(np, clk_gating_get_src, ctrl);
f98d007d	274
f5710531 TP	275	register_syscore_ops(&clk_gate_syscore_ops);
f5710531 TP	276
f98d007d JZ	277	return;
	278	gates_out:
	279	kfree(ctrl);
	280	ctrl_out:
	281	iounmap(base);
a4518409	282	}