[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / clk / spear / clk-gpt-synth.c

/*
 * Copyright (C) 2012 ST Microelectronics
 * Viresh Kumar <viresh.linux@gmail.com>
 *
 * 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.
 *
 * General Purpose Timer Synthesizer clock implementation
 */

#define pr_fmt(fmt) "clk-gpt-synth: " fmt

#include <linux/clk-provider.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/err.h>
#include "clk.h"

#define GPT_MSCALE_MASK		0xFFF
#define GPT_NSCALE_SHIFT	12
#define GPT_NSCALE_MASK		0xF

/*
 * DOC: General Purpose Timer Synthesizer clock
 *
 * Calculates gpt synth clk rate for different values of mscale and nscale
 *
 * Fout= Fin/((2 ^ (N+1)) * (M+1))
 */

#define to_clk_gpt(_hw) container_of(_hw, struct clk_gpt, hw)

static unsigned long gpt_calc_rate(struct clk_hw *hw, unsigned long prate,
		int index)
{
	struct clk_gpt *gpt = to_clk_gpt(hw);
	struct gpt_rate_tbl *rtbl = gpt->rtbl;

	prate /= ((1 << (rtbl[index].nscale + 1)) * (rtbl[index].mscale + 1));

	return prate;
}

static long clk_gpt_round_rate(struct clk_hw *hw, unsigned long drate,
		unsigned long *prate)
{
	struct clk_gpt *gpt = to_clk_gpt(hw);
	int unused;

	return clk_round_rate_index(hw, drate, *prate, gpt_calc_rate,
			gpt->rtbl_cnt, &unused);
}

static unsigned long clk_gpt_recalc_rate(struct clk_hw *hw,
		unsigned long parent_rate)
{
	struct clk_gpt *gpt = to_clk_gpt(hw);
	unsigned long flags = 0;
	unsigned int div = 1, val;

	if (gpt->lock)
		spin_lock_irqsave(gpt->lock, flags);

	val = readl_relaxed(gpt->reg);

	if (gpt->lock)
		spin_unlock_irqrestore(gpt->lock, flags);

	div += val & GPT_MSCALE_MASK;
	div *= 1 << (((val >> GPT_NSCALE_SHIFT) & GPT_NSCALE_MASK) + 1);

	if (!div)
		return 0;

	return parent_rate / div;
}

/* Configures new clock rate of gpt */
static int clk_gpt_set_rate(struct clk_hw *hw, unsigned long drate,
				unsigned long prate)
{
	struct clk_gpt *gpt = to_clk_gpt(hw);
	struct gpt_rate_tbl *rtbl = gpt->rtbl;
	unsigned long flags = 0, val;
	int i;

	clk_round_rate_index(hw, drate, prate, gpt_calc_rate, gpt->rtbl_cnt,
			&i);

	if (gpt->lock)
		spin_lock_irqsave(gpt->lock, flags);

	val = readl(gpt->reg) & ~GPT_MSCALE_MASK;
	val &= ~(GPT_NSCALE_MASK << GPT_NSCALE_SHIFT);

	val |= rtbl[i].mscale & GPT_MSCALE_MASK;
	val |= (rtbl[i].nscale & GPT_NSCALE_MASK) << GPT_NSCALE_SHIFT;

	writel_relaxed(val, gpt->reg);

	if (gpt->lock)
		spin_unlock_irqrestore(gpt->lock, flags);

	return 0;
}

static struct clk_ops clk_gpt_ops = {
	.recalc_rate = clk_gpt_recalc_rate,
	.round_rate = clk_gpt_round_rate,
	.set_rate = clk_gpt_set_rate,
};

struct clk *clk_register_gpt(const char *name, const char *parent_name, unsigned
		long flags, void __iomem *reg, struct gpt_rate_tbl *rtbl, u8
		rtbl_cnt, spinlock_t *lock)
{
	struct clk_init_data init;
	struct clk_gpt *gpt;
	struct clk *clk;

	if (!name || !parent_name || !reg || !rtbl || !rtbl_cnt) {
		pr_err("Invalid arguments passed");
		return ERR_PTR(-EINVAL);
	}

	gpt = kzalloc(sizeof(*gpt), GFP_KERNEL);
	if (!gpt) {
		pr_err("could not allocate gpt clk\n");
		return ERR_PTR(-ENOMEM);
	}

	/* struct clk_gpt assignments */
	gpt->reg = reg;
	gpt->rtbl = rtbl;
	gpt->rtbl_cnt = rtbl_cnt;
	gpt->lock = lock;
	gpt->hw.init = &init;

	init.name = name;
	init.ops = &clk_gpt_ops;
	init.flags = flags;
	init.parent_names = &parent_name;
	init.num_parents = 1;

	clk = clk_register(NULL, &gpt->hw);
	if (!IS_ERR_OR_NULL(clk))
		return clk;

	pr_err("clk register failed\n");
	kfree(gpt);

	return NULL;
}
Commit	Line	Data
a45896bd VK	1	/*
a45896bd VK	2	* Copyright (C) 2012 ST Microelectronics
10d8935f	3	* Viresh Kumar <viresh.linux@gmail.com>
a45896bd VK	4	*
	5	* This file is licensed under the terms of the GNU General Public
	6	* License version 2. This program is licensed "as is" without any
	7	* warranty of any kind, whether express or implied.
	8	*
	9	* General Purpose Timer Synthesizer clock implementation
	10	*/
	11
	12	#define pr_fmt(fmt) "clk-gpt-synth: " fmt
	13
	14	#include <linux/clk-provider.h>
	15	#include <linux/slab.h>
	16	#include <linux/io.h>
	17	#include <linux/err.h>
	18	#include "clk.h"
	19
	20	#define GPT_MSCALE_MASK 0xFFF
	21	#define GPT_NSCALE_SHIFT 12
	22	#define GPT_NSCALE_MASK 0xF
	23
	24	/*
	25	* DOC: General Purpose Timer Synthesizer clock
	26	*
	27	* Calculates gpt synth clk rate for different values of mscale and nscale
	28	*
	29	* Fout= Fin/((2 ^ (N+1)) * (M+1))
	30	*/
	31
	32	#define to_clk_gpt(_hw) container_of(_hw, struct clk_gpt, hw)
	33
	34	static unsigned long gpt_calc_rate(struct clk_hw *hw, unsigned long prate,
	35	int index)
	36	{
	37	struct clk_gpt *gpt = to_clk_gpt(hw);
	38	struct gpt_rate_tbl *rtbl = gpt->rtbl;
	39
	40	prate /= ((1 << (rtbl[index].nscale + 1)) * (rtbl[index].mscale + 1));
	41
	42	return prate;
	43	}
	44
	45	static long clk_gpt_round_rate(struct clk_hw *hw, unsigned long drate,
	46	unsigned long *prate)
	47	{
	48	struct clk_gpt *gpt = to_clk_gpt(hw);
	49	int unused;
	50
	51	return clk_round_rate_index(hw, drate, *prate, gpt_calc_rate,
	52	gpt->rtbl_cnt, &unused);
	53	}
	54
	55	static unsigned long clk_gpt_recalc_rate(struct clk_hw *hw,
	56	unsigned long parent_rate)
	57	{
	58	struct clk_gpt *gpt = to_clk_gpt(hw);
	59	unsigned long flags = 0;
	60	unsigned int div = 1, val;
	61
	62	if (gpt->lock)
	63	spin_lock_irqsave(gpt->lock, flags);
	64
	65	val = readl_relaxed(gpt->reg);
	66
	67	if (gpt->lock)
68	spin_unlock_irqrestore(gpt->lock, flags);
69
70	div += val & GPT_MSCALE_MASK;
71	div *= 1 << (((val >> GPT_NSCALE_SHIFT) & GPT_NSCALE_MASK) + 1);
72
73	if (!div)
74	return 0;
75
76	return parent_rate / div;
77	}
78
79	/* Configures new clock rate of gpt */
80	static int clk_gpt_set_rate(struct clk_hw *hw, unsigned long drate,
81	unsigned long prate)
82	{
83	struct clk_gpt *gpt = to_clk_gpt(hw);
84	struct gpt_rate_tbl *rtbl = gpt->rtbl;
85	unsigned long flags = 0, val;
86	int i;
87
88	clk_round_rate_index(hw, drate, prate, gpt_calc_rate, gpt->rtbl_cnt,
89	&i);
90
91	if (gpt->lock)
92	spin_lock_irqsave(gpt->lock, flags);
93
94	val = readl(gpt->reg) & ~GPT_MSCALE_MASK;
95	val &= ~(GPT_NSCALE_MASK << GPT_NSCALE_SHIFT);
96
97	val \|= rtbl[i].mscale & GPT_MSCALE_MASK;
98	val \|= (rtbl[i].nscale & GPT_NSCALE_MASK) << GPT_NSCALE_SHIFT;
99
100	writel_relaxed(val, gpt->reg);
101
102	if (gpt->lock)
103	spin_unlock_irqrestore(gpt->lock, flags);
104
105	return 0;
106	}
107
108	static struct clk_ops clk_gpt_ops = {
109	.recalc_rate = clk_gpt_recalc_rate,
110	.round_rate = clk_gpt_round_rate,
111	.set_rate = clk_gpt_set_rate,
112	};
113
114	struct clk clk_register_gpt(const char name, const char *parent_name, unsigned
115	long flags, void __iomem reg, struct gpt_rate_tbl rtbl, u8
116	rtbl_cnt, spinlock_t *lock)
117	{
118	struct clk_init_data init;
119	struct clk_gpt *gpt;
120	struct clk *clk;
121
122	if (!name \|\| !parent_name \|\| !reg \|\| !rtbl \|\| !rtbl_cnt) {
123	pr_err("Invalid arguments passed");
124	return ERR_PTR(-EINVAL);
125	}
126
127	gpt = kzalloc(sizeof(*gpt), GFP_KERNEL);
128	if (!gpt) {
129	pr_err("could not allocate gpt clk\n");
130	return ERR_PTR(-ENOMEM);
131	}
132
133	/* struct clk_gpt assignments */
134	gpt->reg = reg;
135	gpt->rtbl = rtbl;
136	gpt->rtbl_cnt = rtbl_cnt;
137	gpt->lock = lock;
138	gpt->hw.init = &init;
139
140	init.name = name;
141	init.ops = &clk_gpt_ops;
142	init.flags = flags;
143	init.parent_names = &parent_name;
144	init.num_parents = 1;
145
146	clk = clk_register(NULL, &gpt->hw);
147	if (!IS_ERR_OR_NULL(clk))
148	return clk;
149
150	pr_err("clk register failed\n");
151	kfree(gpt);
152
153	return NULL;
154	}