[deliverable/linux.git] / drivers / clk / at91 / clk-main.c

/*
 *  Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.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/clkdev.h>
#include <linux/clk/at91_pmc.h>
#include <linux/delay.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/io.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/sched.h>
#include <linux/wait.h>

#include "pmc.h"

#define SLOW_CLOCK_FREQ		32768
#define MAINF_DIV		16
#define MAINFRDY_TIMEOUT	(((MAINF_DIV + 1) * USEC_PER_SEC) / \
				 SLOW_CLOCK_FREQ)
#define MAINF_LOOP_MIN_WAIT	(USEC_PER_SEC / SLOW_CLOCK_FREQ)
#define MAINF_LOOP_MAX_WAIT	MAINFRDY_TIMEOUT

struct clk_main {
	struct clk_hw hw;
	struct at91_pmc *pmc;
	unsigned long rate;
	unsigned int irq;
	wait_queue_head_t wait;
};

#define to_clk_main(hw) container_of(hw, struct clk_main, hw)

static irqreturn_t clk_main_irq_handler(int irq, void *dev_id)
{
	struct clk_main *clkmain = (struct clk_main *)dev_id;

	wake_up(&clkmain->wait);
	disable_irq_nosync(clkmain->irq);

	return IRQ_HANDLED;
}

static int clk_main_prepare(struct clk_hw *hw)
{
	struct clk_main *clkmain = to_clk_main(hw);
	struct at91_pmc *pmc = clkmain->pmc;
	unsigned long halt_time, timeout;
	u32 tmp;

	while (!(pmc_read(pmc, AT91_PMC_SR) & AT91_PMC_MOSCS)) {
		enable_irq(clkmain->irq);
		wait_event(clkmain->wait,
			   pmc_read(pmc, AT91_PMC_SR) & AT91_PMC_MOSCS);
	}

	if (clkmain->rate)
		return 0;

	timeout = jiffies + usecs_to_jiffies(MAINFRDY_TIMEOUT);
	do {
		halt_time = jiffies;
		tmp = pmc_read(pmc, AT91_CKGR_MCFR);
		if (tmp & AT91_PMC_MAINRDY)
			return 0;
		usleep_range(MAINF_LOOP_MIN_WAIT, MAINF_LOOP_MAX_WAIT);
	} while (time_before(halt_time, timeout));

	return 0;
}

static int clk_main_is_prepared(struct clk_hw *hw)
{
	struct clk_main *clkmain = to_clk_main(hw);

	return !!(pmc_read(clkmain->pmc, AT91_PMC_SR) & AT91_PMC_MOSCS);
}

static unsigned long clk_main_recalc_rate(struct clk_hw *hw,
					  unsigned long parent_rate)
{
	u32 tmp;
	struct clk_main *clkmain = to_clk_main(hw);
	struct at91_pmc *pmc = clkmain->pmc;

	if (clkmain->rate)
		return clkmain->rate;

	tmp = pmc_read(pmc, AT91_CKGR_MCFR) & AT91_PMC_MAINF;
	clkmain->rate = (tmp * parent_rate) / MAINF_DIV;

	return clkmain->rate;
}

static const struct clk_ops main_ops = {
	.prepare = clk_main_prepare,
	.is_prepared = clk_main_is_prepared,
	.recalc_rate = clk_main_recalc_rate,
};

static struct clk * __init
at91_clk_register_main(struct at91_pmc *pmc,
		       unsigned int irq,
		       const char *name,
		       const char *parent_name,
		       unsigned long rate)
{
	int ret;
	struct clk_main *clkmain;
	struct clk *clk = NULL;
	struct clk_init_data init;

	if (!pmc || !irq || !name)
		return ERR_PTR(-EINVAL);

	if (!rate && !parent_name)
		return ERR_PTR(-EINVAL);

	clkmain = kzalloc(sizeof(*clkmain), GFP_KERNEL);
	if (!clkmain)
		return ERR_PTR(-ENOMEM);

	init.name = name;
	init.ops = &main_ops;
	init.parent_names = parent_name ? &parent_name : NULL;
	init.num_parents = parent_name ? 1 : 0;
	init.flags = parent_name ? 0 : CLK_IS_ROOT;

	clkmain->hw.init = &init;
	clkmain->rate = rate;
	clkmain->pmc = pmc;
	clkmain->irq = irq;
	init_waitqueue_head(&clkmain->wait);
	irq_set_status_flags(clkmain->irq, IRQ_NOAUTOEN);
	ret = request_irq(clkmain->irq, clk_main_irq_handler,
			  IRQF_TRIGGER_HIGH, "clk-main", clkmain);
	if (ret)
		return ERR_PTR(ret);

	clk = clk_register(NULL, &clkmain->hw);
	if (IS_ERR(clk)) {
		free_irq(clkmain->irq, clkmain);
		kfree(clkmain);
	}

	return clk;
}


static void __init
of_at91_clk_main_setup(struct device_node *np, struct at91_pmc *pmc)
{
	struct clk *clk;
	unsigned int irq;
	const char *parent_name;
	const char *name = np->name;
	u32 rate = 0;

	parent_name = of_clk_get_parent_name(np, 0);
	of_property_read_string(np, "clock-output-names", &name);
	of_property_read_u32(np, "clock-frequency", &rate);
	irq = irq_of_parse_and_map(np, 0);
	if (!irq)
		return;

	clk = at91_clk_register_main(pmc, irq, name, parent_name, rate);
	if (IS_ERR(clk))
		return;

	of_clk_add_provider(np, of_clk_src_simple_get, clk);
}

void __init of_at91rm9200_clk_main_setup(struct device_node *np,
					 struct at91_pmc *pmc)
{
	of_at91_clk_main_setup(np, pmc);
}
Commit	Line	Data
38d34c31 BB	1	/*
	2	* Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com>
	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License as published by
	6	* the Free Software Foundation; either version 2 of the License, or
	7	* (at your option) any later version.
	8	*
	9	*/
	10
	11	#include <linux/clk-provider.h>
	12	#include <linux/clkdev.h>
	13	#include <linux/clk/at91_pmc.h>
	14	#include <linux/delay.h>
	15	#include <linux/of.h>
	16	#include <linux/of_address.h>
	17	#include <linux/of_irq.h>
	18	#include <linux/io.h>
	19	#include <linux/interrupt.h>
	20	#include <linux/irq.h>
	21	#include <linux/sched.h>
	22	#include <linux/wait.h>
	23
	24	#include "pmc.h"
	25
	26	#define SLOW_CLOCK_FREQ 32768
	27	#define MAINF_DIV 16
	28	#define MAINFRDY_TIMEOUT (((MAINF_DIV + 1) * USEC_PER_SEC) / \
	29	SLOW_CLOCK_FREQ)
	30	#define MAINF_LOOP_MIN_WAIT (USEC_PER_SEC / SLOW_CLOCK_FREQ)
	31	#define MAINF_LOOP_MAX_WAIT MAINFRDY_TIMEOUT
	32
	33	struct clk_main {
	34	struct clk_hw hw;
	35	struct at91_pmc *pmc;
	36	unsigned long rate;
	37	unsigned int irq;
	38	wait_queue_head_t wait;
	39	};
	40
	41	#define to_clk_main(hw) container_of(hw, struct clk_main, hw)
	42
	43	static irqreturn_t clk_main_irq_handler(int irq, void *dev_id)
	44	{
	45	struct clk_main clkmain = (struct clk_main )dev_id;
	46
	47	wake_up(&clkmain->wait);
	48	disable_irq_nosync(clkmain->irq);
	49
	50	return IRQ_HANDLED;
	51	}
	52
	53	static int clk_main_prepare(struct clk_hw *hw)
	54	{
	55	struct clk_main *clkmain = to_clk_main(hw);
	56	struct at91_pmc *pmc = clkmain->pmc;
	57	unsigned long halt_time, timeout;
	58	u32 tmp;
	59
	60	while (!(pmc_read(pmc, AT91_PMC_SR) & AT91_PMC_MOSCS)) {
	61	enable_irq(clkmain->irq);
	62	wait_event(clkmain->wait,
	63	pmc_read(pmc, AT91_PMC_SR) & AT91_PMC_MOSCS);
	64	}
65
66	if (clkmain->rate)
67	return 0;
68
69	timeout = jiffies + usecs_to_jiffies(MAINFRDY_TIMEOUT);
70	do {
71	halt_time = jiffies;
72	tmp = pmc_read(pmc, AT91_CKGR_MCFR);
73	if (tmp & AT91_PMC_MAINRDY)
74	return 0;
75	usleep_range(MAINF_LOOP_MIN_WAIT, MAINF_LOOP_MAX_WAIT);
76	} while (time_before(halt_time, timeout));
77
78	return 0;
79	}
80
81	static int clk_main_is_prepared(struct clk_hw *hw)
82	{
83	struct clk_main *clkmain = to_clk_main(hw);
84
85	return !!(pmc_read(clkmain->pmc, AT91_PMC_SR) & AT91_PMC_MOSCS);
86	}
87
88	static unsigned long clk_main_recalc_rate(struct clk_hw *hw,
89	unsigned long parent_rate)
90	{
91	u32 tmp;
92	struct clk_main *clkmain = to_clk_main(hw);
93	struct at91_pmc *pmc = clkmain->pmc;
94
95	if (clkmain->rate)
96	return clkmain->rate;
97
98	tmp = pmc_read(pmc, AT91_CKGR_MCFR) & AT91_PMC_MAINF;
99	clkmain->rate = (tmp * parent_rate) / MAINF_DIV;
100
101	return clkmain->rate;
102	}
103
104	static const struct clk_ops main_ops = {
105	.prepare = clk_main_prepare,
106	.is_prepared = clk_main_is_prepared,
107	.recalc_rate = clk_main_recalc_rate,
108	};
109
110	static struct clk * __init
111	at91_clk_register_main(struct at91_pmc *pmc,
112	unsigned int irq,
113	const char *name,
114	const char *parent_name,
115	unsigned long rate)
116	{
117	int ret;
118	struct clk_main *clkmain;
119	struct clk *clk = NULL;
120	struct clk_init_data init;
121
122	if (!pmc \|\| !irq \|\| !name)
123	return ERR_PTR(-EINVAL);
124
125	if (!rate && !parent_name)
126	return ERR_PTR(-EINVAL);
127
128	clkmain = kzalloc(sizeof(*clkmain), GFP_KERNEL);
129	if (!clkmain)
130	return ERR_PTR(-ENOMEM);
131
132	init.name = name;
133	init.ops = &main_ops;
134	init.parent_names = parent_name ? &parent_name : NULL;
135	init.num_parents = parent_name ? 1 : 0;
136	init.flags = parent_name ? 0 : CLK_IS_ROOT;
137
138	clkmain->hw.init = &init;
139	clkmain->rate = rate;
140	clkmain->pmc = pmc;
141	clkmain->irq = irq;
142	init_waitqueue_head(&clkmain->wait);
143	irq_set_status_flags(clkmain->irq, IRQ_NOAUTOEN);
144	ret = request_irq(clkmain->irq, clk_main_irq_handler,
145	IRQF_TRIGGER_HIGH, "clk-main", clkmain);
146	if (ret)
147	return ERR_PTR(ret);
148
149	clk = clk_register(NULL, &clkmain->hw);
150	if (IS_ERR(clk)) {
151	free_irq(clkmain->irq, clkmain);
152	kfree(clkmain);
153	}
154
155	return clk;
156	}
157
158
159
160	static void __init
161	of_at91_clk_main_setup(struct device_node np, struct at91_pmc pmc)
162	{
163	struct clk *clk;
164	unsigned int irq;
165	const char *parent_name;
166	const char *name = np->name;
167	u32 rate = 0;
168
169	parent_name = of_clk_get_parent_name(np, 0);
170	of_property_read_string(np, "clock-output-names", &name);
171	of_property_read_u32(np, "clock-frequency", &rate);
172	irq = irq_of_parse_and_map(np, 0);
173	if (!irq)
174	return;
175
176	clk = at91_clk_register_main(pmc, irq, name, parent_name, rate);
177	if (IS_ERR(clk))
178	return;
179
180	of_clk_add_provider(np, of_clk_src_simple_get, clk);
181	}
182
183	void __init of_at91rm9200_clk_main_setup(struct device_node *np,
184	struct at91_pmc *pmc)
185	{
186	of_at91_clk_main_setup(np, pmc);
187	}