[mirror_ubuntu-jammy-kernel.git] / drivers / clk / at91 / clk-generated.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  Copyright (C) 2015 Atmel Corporation,
 *                     Nicolas Ferre <nicolas.ferre@atmel.com>
 *
 * Based on clk-programmable & clk-peripheral drivers by Boris BREZILLON.
 */

#include <linux/bitfield.h>
#include <linux/clk-provider.h>
#include <linux/clkdev.h>
#include <linux/clk/at91_pmc.h>
#include <linux/of.h>
#include <linux/mfd/syscon.h>
#include <linux/regmap.h>

#include "pmc.h"

#define GENERATED_MAX_DIV	255

#define GCK_INDEX_DT_AUDIO_PLL	5

struct clk_generated {
	struct clk_hw hw;
	struct regmap *regmap;
	struct clk_range range;
	spinlock_t *lock;
	u32 id;
	u32 gckdiv;
	const struct clk_pcr_layout *layout;
	u8 parent_id;
	bool audio_pll_allowed;
};

#define to_clk_generated(hw) \
	container_of(hw, struct clk_generated, hw)

static int clk_generated_enable(struct clk_hw *hw)
{
	struct clk_generated *gck = to_clk_generated(hw);
	unsigned long flags;

	pr_debug("GCLK: %s, gckdiv = %d, parent id = %d\n",
		 __func__, gck->gckdiv, gck->parent_id);

	spin_lock_irqsave(gck->lock, flags);
	regmap_write(gck->regmap, gck->layout->offset,
		     (gck->id & gck->layout->pid_mask));
	regmap_update_bits(gck->regmap, gck->layout->offset,
			   AT91_PMC_PCR_GCKDIV_MASK | gck->layout->gckcss_mask |
			   gck->layout->cmd | AT91_PMC_PCR_GCKEN,
			   field_prep(gck->layout->gckcss_mask, gck->parent_id) |
			   gck->layout->cmd |
			   FIELD_PREP(AT91_PMC_PCR_GCKDIV_MASK, gck->gckdiv) |
			   AT91_PMC_PCR_GCKEN);
	spin_unlock_irqrestore(gck->lock, flags);
	return 0;
}

static void clk_generated_disable(struct clk_hw *hw)
{
	struct clk_generated *gck = to_clk_generated(hw);
	unsigned long flags;

	spin_lock_irqsave(gck->lock, flags);
	regmap_write(gck->regmap, gck->layout->offset,
		     (gck->id & gck->layout->pid_mask));
	regmap_update_bits(gck->regmap, gck->layout->offset,
			   gck->layout->cmd | AT91_PMC_PCR_GCKEN,
			   gck->layout->cmd);
	spin_unlock_irqrestore(gck->lock, flags);
}

static int clk_generated_is_enabled(struct clk_hw *hw)
{
	struct clk_generated *gck = to_clk_generated(hw);
	unsigned long flags;
	unsigned int status;

	spin_lock_irqsave(gck->lock, flags);
	regmap_write(gck->regmap, gck->layout->offset,
		     (gck->id & gck->layout->pid_mask));
	regmap_read(gck->regmap, gck->layout->offset, &status);
	spin_unlock_irqrestore(gck->lock, flags);

	return status & AT91_PMC_PCR_GCKEN ? 1 : 0;
}

static unsigned long
clk_generated_recalc_rate(struct clk_hw *hw,
			  unsigned long parent_rate)
{
	struct clk_generated *gck = to_clk_generated(hw);

	return DIV_ROUND_CLOSEST(parent_rate, gck->gckdiv + 1);
}

static void clk_generated_best_diff(struct clk_rate_request *req,
				    struct clk_hw *parent,
				    unsigned long parent_rate, u32 div,
				    int *best_diff, long *best_rate)
{
	unsigned long tmp_rate;
	int tmp_diff;

	if (!div)
		tmp_rate = parent_rate;
	else
		tmp_rate = parent_rate / div;
	tmp_diff = abs(req->rate - tmp_rate);

	if (*best_diff < 0 || *best_diff > tmp_diff) {
		*best_rate = tmp_rate;
		*best_diff = tmp_diff;
		req->best_parent_rate = parent_rate;
		req->best_parent_hw = parent;
	}
}

static int clk_generated_determine_rate(struct clk_hw *hw,
					struct clk_rate_request *req)
{
	struct clk_generated *gck = to_clk_generated(hw);
	struct clk_hw *parent = NULL;
	struct clk_rate_request req_parent = *req;
	long best_rate = -EINVAL;
	unsigned long min_rate, parent_rate;
	int best_diff = -1;
	int i;
	u32 div;

	for (i = 0; i < clk_hw_get_num_parents(hw) - 1; i++) {
		parent = clk_hw_get_parent_by_index(hw, i);
		if (!parent)
			continue;

		parent_rate = clk_hw_get_rate(parent);
		min_rate = DIV_ROUND_CLOSEST(parent_rate, GENERATED_MAX_DIV + 1);
		if (!parent_rate ||
		    (gck->range.max && min_rate > gck->range.max))
			continue;

		div = DIV_ROUND_CLOSEST(parent_rate, req->rate);
		if (div > GENERATED_MAX_DIV + 1)
			div = GENERATED_MAX_DIV + 1;

		clk_generated_best_diff(req, parent, parent_rate, div,
					&best_diff, &best_rate);

		if (!best_diff)
			break;
	}

	/*
	 * The audio_pll rate can be modified, unlike the five others clocks
	 * that should never be altered.
	 * The audio_pll can technically be used by multiple consumers. However,
	 * with the rate locking, the first consumer to enable to clock will be
	 * the one definitely setting the rate of the clock.
	 * Since audio IPs are most likely to request the same rate, we enforce
	 * that the only clks able to modify gck rate are those of audio IPs.
	 */

	if (!gck->audio_pll_allowed)
		goto end;

	parent = clk_hw_get_parent_by_index(hw, GCK_INDEX_DT_AUDIO_PLL);
	if (!parent)
		goto end;

	for (div = 1; div < GENERATED_MAX_DIV + 2; div++) {
		req_parent.rate = req->rate * div;
		__clk_determine_rate(parent, &req_parent);
		clk_generated_best_diff(req, parent, req_parent.rate, div,
					&best_diff, &best_rate);

		if (!best_diff)
			break;
	}

end:
	pr_debug("GCLK: %s, best_rate = %ld, parent clk: %s @ %ld\n",
		 __func__, best_rate,
		 __clk_get_name((req->best_parent_hw)->clk),
		 req->best_parent_rate);

	if (best_rate < 0)
		return best_rate;

	req->rate = best_rate;
	return 0;
}

/* No modification of hardware as we have the flag CLK_SET_PARENT_GATE set */
static int clk_generated_set_parent(struct clk_hw *hw, u8 index)
{
	struct clk_generated *gck = to_clk_generated(hw);

	if (index >= clk_hw_get_num_parents(hw))
		return -EINVAL;

	gck->parent_id = index;
	return 0;
}

static u8 clk_generated_get_parent(struct clk_hw *hw)
{
	struct clk_generated *gck = to_clk_generated(hw);

	return gck->parent_id;
}

/* No modification of hardware as we have the flag CLK_SET_RATE_GATE set */
static int clk_generated_set_rate(struct clk_hw *hw,
				  unsigned long rate,
				  unsigned long parent_rate)
{
	struct clk_generated *gck = to_clk_generated(hw);
	u32 div;

	if (!rate)
		return -EINVAL;

	if (gck->range.max && rate > gck->range.max)
		return -EINVAL;

	div = DIV_ROUND_CLOSEST(parent_rate, rate);
	if (div > GENERATED_MAX_DIV + 1 || !div)
		return -EINVAL;

	gck->gckdiv = div - 1;
	return 0;
}

static const struct clk_ops generated_ops = {
	.enable = clk_generated_enable,
	.disable = clk_generated_disable,
	.is_enabled = clk_generated_is_enabled,
	.recalc_rate = clk_generated_recalc_rate,
	.determine_rate = clk_generated_determine_rate,
	.get_parent = clk_generated_get_parent,
	.set_parent = clk_generated_set_parent,
	.set_rate = clk_generated_set_rate,
};

/**
 * clk_generated_startup - Initialize a given clock to its default parent and
 * divisor parameter.
 *
 * @gck:	Generated clock to set the startup parameters for.
 *
 * Take parameters from the hardware and update local clock configuration
 * accordingly.
 */
static void clk_generated_startup(struct clk_generated *gck)
{
	u32 tmp;
	unsigned long flags;

	spin_lock_irqsave(gck->lock, flags);
	regmap_write(gck->regmap, gck->layout->offset,
		     (gck->id & gck->layout->pid_mask));
	regmap_read(gck->regmap, gck->layout->offset, &tmp);
	spin_unlock_irqrestore(gck->lock, flags);

	gck->parent_id = field_get(gck->layout->gckcss_mask, tmp);
	gck->gckdiv = FIELD_GET(AT91_PMC_PCR_GCKDIV_MASK, tmp);
}

struct clk_hw * __init
at91_clk_register_generated(struct regmap *regmap, spinlock_t *lock,
			    const struct clk_pcr_layout *layout,
			    const char *name, const char **parent_names,
			    u8 num_parents, u8 id, bool pll_audio,
			    const struct clk_range *range)
{
	struct clk_generated *gck;
	struct clk_init_data init;
	struct clk_hw *hw;
	int ret;

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

	init.name = name;
	init.ops = &generated_ops;
	init.parent_names = parent_names;
	init.num_parents = num_parents;
	init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE |
		CLK_SET_RATE_PARENT;

	gck->id = id;
	gck->hw.init = &init;
	gck->regmap = regmap;
	gck->lock = lock;
	gck->range = *range;
	gck->audio_pll_allowed = pll_audio;
	gck->layout = layout;

	clk_generated_startup(gck);
	hw = &gck->hw;
	ret = clk_hw_register(NULL, &gck->hw);
	if (ret) {
		kfree(gck);
		hw = ERR_PTR(ret);
	} else {
		pmc_register_id(id);
	}

	return hw;
}
Commit	Line	Data
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
df70aeef NF	2	/*
	3	* Copyright (C) 2015 Atmel Corporation,
	4	* Nicolas Ferre <nicolas.ferre@atmel.com>
	5	*
	6	* Based on clk-programmable & clk-peripheral drivers by Boris BREZILLON.
df70aeef NF	7	*/
df70aeef NF	8
e4cfb823	9	#include <linux/bitfield.h>
df70aeef NF	10	#include <linux/clk-provider.h>
	11	#include <linux/clkdev.h>
	12	#include <linux/clk/at91_pmc.h>
	13	#include <linux/of.h>
1bdf0232 BB	14	#include <linux/mfd/syscon.h>
1bdf0232 BB	15	#include <linux/regmap.h>
df70aeef NF	16
	17	#include "pmc.h"
	18
df70aeef NF	19	#define GENERATED_MAX_DIV 255
df70aeef NF	20
1a1a36d7 QS	21	#define GCK_INDEX_DT_AUDIO_PLL 5
1a1a36d7 QS	22
df70aeef NF	23	struct clk_generated {
df70aeef NF	24	struct clk_hw hw;
1bdf0232	25	struct regmap *regmap;
df70aeef	26	struct clk_range range;
1bdf0232	27	spinlock_t *lock;
df70aeef NF	28	u32 id;
df70aeef NF	29	u32 gckdiv;
e4cfb823	30	const struct clk_pcr_layout *layout;
df70aeef	31	u8 parent_id;
1a1a36d7	32	bool audio_pll_allowed;
df70aeef NF	33	};
	34
	35	#define to_clk_generated(hw) \
	36	container_of(hw, struct clk_generated, hw)
	37
	38	static int clk_generated_enable(struct clk_hw *hw)
	39	{
	40	struct clk_generated *gck = to_clk_generated(hw);
1bdf0232	41	unsigned long flags;
df70aeef NF	42
	43	pr_debug("GCLK: %s, gckdiv = %d, parent id = %d\n",
	44	__func__, gck->gckdiv, gck->parent_id);
	45
1bdf0232	46	spin_lock_irqsave(gck->lock, flags);
e4cfb823 AB	47	regmap_write(gck->regmap, gck->layout->offset,
	48	(gck->id & gck->layout->pid_mask));
	49	regmap_update_bits(gck->regmap, gck->layout->offset,
	50	AT91_PMC_PCR_GCKDIV_MASK \| gck->layout->gckcss_mask \|
	51	gck->layout->cmd \| AT91_PMC_PCR_GCKEN,
	52	field_prep(gck->layout->gckcss_mask, gck->parent_id) \|
	53	gck->layout->cmd \|
	54	FIELD_PREP(AT91_PMC_PCR_GCKDIV_MASK, gck->gckdiv) \|
1bdf0232 BB	55	AT91_PMC_PCR_GCKEN);
1bdf0232 BB	56	spin_unlock_irqrestore(gck->lock, flags);
df70aeef NF	57	return 0;
	58	}
	59
	60	static void clk_generated_disable(struct clk_hw *hw)
	61	{
	62	struct clk_generated *gck = to_clk_generated(hw);
1bdf0232 BB	63	unsigned long flags;
	64
	65	spin_lock_irqsave(gck->lock, flags);
e4cfb823 AB	66	regmap_write(gck->regmap, gck->layout->offset,
	67	(gck->id & gck->layout->pid_mask));
	68	regmap_update_bits(gck->regmap, gck->layout->offset,
	69	gck->layout->cmd \| AT91_PMC_PCR_GCKEN,
	70	gck->layout->cmd);
1bdf0232	71	spin_unlock_irqrestore(gck->lock, flags);
df70aeef NF	72	}
	73
	74	static int clk_generated_is_enabled(struct clk_hw *hw)
	75	{
	76	struct clk_generated *gck = to_clk_generated(hw);
1bdf0232 BB	77	unsigned long flags;
1bdf0232 BB	78	unsigned int status;
df70aeef	79
1bdf0232	80	spin_lock_irqsave(gck->lock, flags);
e4cfb823 AB	81	regmap_write(gck->regmap, gck->layout->offset,
	82	(gck->id & gck->layout->pid_mask));
	83	regmap_read(gck->regmap, gck->layout->offset, &status);
1bdf0232	84	spin_unlock_irqrestore(gck->lock, flags);
df70aeef	85
1bdf0232	86	return status & AT91_PMC_PCR_GCKEN ? 1 : 0;
df70aeef NF	87	}
	88
	89	static unsigned long
	90	clk_generated_recalc_rate(struct clk_hw *hw,
	91	unsigned long parent_rate)
	92	{
	93	struct clk_generated *gck = to_clk_generated(hw);
	94
	95	return DIV_ROUND_CLOSEST(parent_rate, gck->gckdiv + 1);
	96	}
	97
8a8f4bf0 QS	98	static void clk_generated_best_diff(struct clk_rate_request *req,
	99	struct clk_hw *parent,
	100	unsigned long parent_rate, u32 div,
	101	int best_diff, long best_rate)
	102	{
	103	unsigned long tmp_rate;
	104	int tmp_diff;
	105
	106	if (!div)
	107	tmp_rate = parent_rate;
	108	else
	109	tmp_rate = parent_rate / div;
	110	tmp_diff = abs(req->rate - tmp_rate);
	111
	112	if (best_diff < 0 \|\| best_diff > tmp_diff) {
	113	*best_rate = tmp_rate;
	114	*best_diff = tmp_diff;
	115	req->best_parent_rate = parent_rate;
	116	req->best_parent_hw = parent;
	117	}
	118	}
	119
df70aeef NF	120	static int clk_generated_determine_rate(struct clk_hw *hw,
	121	struct clk_rate_request *req)
	122	{
	123	struct clk_generated *gck = to_clk_generated(hw);
	124	struct clk_hw *parent = NULL;
1a1a36d7	125	struct clk_rate_request req_parent = *req;
df70aeef	126	long best_rate = -EINVAL;
1a1a36d7	127	unsigned long min_rate, parent_rate;
df70aeef	128	int best_diff = -1;
df70aeef	129	int i;
1a1a36d7	130	u32 div;
df70aeef	131
1a1a36d7	132	for (i = 0; i < clk_hw_get_num_parents(hw) - 1; i++) {
df70aeef NF	133	parent = clk_hw_get_parent_by_index(hw, i);
	134	if (!parent)
	135	continue;
	136
	137	parent_rate = clk_hw_get_rate(parent);
	138	min_rate = DIV_ROUND_CLOSEST(parent_rate, GENERATED_MAX_DIV + 1);
	139	if (!parent_rate \|\|
	140	(gck->range.max && min_rate > gck->range.max))
	141	continue;
	142
8c7aa632	143	div = DIV_ROUND_CLOSEST(parent_rate, req->rate);
1573eebe CC	144	if (div > GENERATED_MAX_DIV + 1)
1573eebe CC	145	div = GENERATED_MAX_DIV + 1;
8a8f4bf0 QS	146
	147	clk_generated_best_diff(req, parent, parent_rate, div,
	148	&best_diff, &best_rate);
	149
1a1a36d7 QS	150	if (!best_diff)
	151	break;
	152	}
	153
	154	/*
	155	* The audio_pll rate can be modified, unlike the five others clocks
	156	* that should never be altered.
	157	* The audio_pll can technically be used by multiple consumers. However,
	158	* with the rate locking, the first consumer to enable to clock will be
	159	* the one definitely setting the rate of the clock.
	160	* Since audio IPs are most likely to request the same rate, we enforce
	161	* that the only clks able to modify gck rate are those of audio IPs.
	162	*/
	163
	164	if (!gck->audio_pll_allowed)
	165	goto end;
	166
	167	parent = clk_hw_get_parent_by_index(hw, GCK_INDEX_DT_AUDIO_PLL);
	168	if (!parent)
	169	goto end;
	170
	171	for (div = 1; div < GENERATED_MAX_DIV + 2; div++) {
	172	req_parent.rate = req->rate * div;
	173	__clk_determine_rate(parent, &req_parent);
	174	clk_generated_best_diff(req, parent, req_parent.rate, div,
	175	&best_diff, &best_rate);
df70aeef NF	176
	177	if (!best_diff)
	178	break;
	179	}
	180
1a1a36d7	181	end:
df70aeef NF	182	pr_debug("GCLK: %s, best_rate = %ld, parent clk: %s @ %ld\n",
	183	__func__, best_rate,
	184	__clk_get_name((req->best_parent_hw)->clk),
	185	req->best_parent_rate);
	186
	187	if (best_rate < 0)
	188	return best_rate;
	189
	190	req->rate = best_rate;
	191	return 0;
	192	}
	193
	194	/* No modification of hardware as we have the flag CLK_SET_PARENT_GATE set */
	195	static int clk_generated_set_parent(struct clk_hw *hw, u8 index)
	196	{
	197	struct clk_generated *gck = to_clk_generated(hw);
	198
	199	if (index >= clk_hw_get_num_parents(hw))
	200	return -EINVAL;
	201
	202	gck->parent_id = index;
	203	return 0;
	204	}
	205
	206	static u8 clk_generated_get_parent(struct clk_hw *hw)
	207	{
	208	struct clk_generated *gck = to_clk_generated(hw);
	209
	210	return gck->parent_id;
	211	}
	212
	213	/* No modification of hardware as we have the flag CLK_SET_RATE_GATE set */
	214	static int clk_generated_set_rate(struct clk_hw *hw,
	215	unsigned long rate,
	216	unsigned long parent_rate)
	217	{
	218	struct clk_generated *gck = to_clk_generated(hw);
	219	u32 div;
	220
	221	if (!rate)
	222	return -EINVAL;
	223
	224	if (gck->range.max && rate > gck->range.max)
	225	return -EINVAL;
	226
	227	div = DIV_ROUND_CLOSEST(parent_rate, rate);
	228	if (div > GENERATED_MAX_DIV + 1 \|\| !div)
	229	return -EINVAL;
	230
	231	gck->gckdiv = div - 1;
	232	return 0;
	233	}
	234
	235	static const struct clk_ops generated_ops = {
	236	.enable = clk_generated_enable,
	237	.disable = clk_generated_disable,
	238	.is_enabled = clk_generated_is_enabled,
	239	.recalc_rate = clk_generated_recalc_rate,
	240	.determine_rate = clk_generated_determine_rate,
	241	.get_parent = clk_generated_get_parent,
	242	.set_parent = clk_generated_set_parent,
	243	.set_rate = clk_generated_set_rate,
	244	};
	245
246	/**
247	* clk_generated_startup - Initialize a given clock to its default parent and
248	* divisor parameter.
249	*
250	* @gck: Generated clock to set the startup parameters for.
251	*
252	* Take parameters from the hardware and update local clock configuration
253	* accordingly.
254	*/
255	static void clk_generated_startup(struct clk_generated *gck)
256	{
df70aeef	257	u32 tmp;
1bdf0232	258	unsigned long flags;
df70aeef	259
1bdf0232	260	spin_lock_irqsave(gck->lock, flags);
e4cfb823 AB	261	regmap_write(gck->regmap, gck->layout->offset,
	262	(gck->id & gck->layout->pid_mask));
	263	regmap_read(gck->regmap, gck->layout->offset, &tmp);
1bdf0232	264	spin_unlock_irqrestore(gck->lock, flags);
df70aeef	265
e4cfb823 AB	266	gck->parent_id = field_get(gck->layout->gckcss_mask, tmp);
e4cfb823 AB	267	gck->gckdiv = FIELD_GET(AT91_PMC_PCR_GCKDIV_MASK, tmp);
df70aeef NF	268	}
df70aeef NF	269
b2e39dc0	270	struct clk_hw * __init
f5644f10	271	at91_clk_register_generated(struct regmap regmap, spinlock_t lock,
e4cfb823	272	const struct clk_pcr_layout *layout,
f5644f10	273	const char name, const char *parent_names,
c1e4580a	274	u8 num_parents, u8 id, bool pll_audio,
f5644f10	275	const struct clk_range *range)
df70aeef NF	276	{
df70aeef NF	277	struct clk_generated *gck;
df70aeef	278	struct clk_init_data init;
f5644f10 SB	279	struct clk_hw *hw;
f5644f10 SB	280	int ret;
df70aeef NF	281
	282	gck = kzalloc(sizeof(*gck), GFP_KERNEL);
	283	if (!gck)
	284	return ERR_PTR(-ENOMEM);
	285
	286	init.name = name;
	287	init.ops = &generated_ops;
	288	init.parent_names = parent_names;
	289	init.num_parents = num_parents;
1a1a36d7 QS	290	init.flags = CLK_SET_RATE_GATE \| CLK_SET_PARENT_GATE \|
1a1a36d7 QS	291	CLK_SET_RATE_PARENT;
df70aeef NF	292
	293	gck->id = id;
	294	gck->hw.init = &init;
1bdf0232 BB	295	gck->regmap = regmap;
1bdf0232 BB	296	gck->lock = lock;
df70aeef	297	gck->range = *range;
c1e4580a	298	gck->audio_pll_allowed = pll_audio;
e4cfb823	299	gck->layout = layout;
df70aeef	300
8e56133e	301	clk_generated_startup(gck);
f5644f10 SB	302	hw = &gck->hw;
	303	ret = clk_hw_register(NULL, &gck->hw);
	304	if (ret) {
df70aeef	305	kfree(gck);
f5644f10	306	hw = ERR_PTR(ret);
b3b02eac AB	307	} else {
b3b02eac AB	308	pmc_register_id(id);
4a5f06a0	309	}
df70aeef	310
f5644f10	311	return hw;
df70aeef	312	}