cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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clk-master.c (22687B)


      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 *  Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com>
      4 */
      5
      6#include <linux/clk-provider.h>
      7#include <linux/clkdev.h>
      8#include <linux/clk.h>
      9#include <linux/clk/at91_pmc.h>
     10#include <linux/of.h>
     11#include <linux/mfd/syscon.h>
     12#include <linux/regmap.h>
     13
     14#include "pmc.h"
     15
     16#define MASTER_PRES_MASK	0x7
     17#define MASTER_PRES_MAX		MASTER_PRES_MASK
     18#define MASTER_DIV_SHIFT	8
     19#define MASTER_DIV_MASK		0x7
     20
     21#define PMC_MCR_CSS_SHIFT	(16)
     22
     23#define MASTER_MAX_ID		4
     24
     25#define to_clk_master(hw) container_of(hw, struct clk_master, hw)
     26
     27struct clk_master {
     28	struct clk_hw hw;
     29	struct regmap *regmap;
     30	spinlock_t *lock;
     31	const struct clk_master_layout *layout;
     32	const struct clk_master_characteristics *characteristics;
     33	struct at91_clk_pms pms;
     34	u32 *mux_table;
     35	u32 mckr;
     36	int chg_pid;
     37	u8 id;
     38	u8 parent;
     39	u8 div;
     40	u32 safe_div;
     41};
     42
     43/* MCK div reference to be used by notifier. */
     44static struct clk_master *master_div;
     45
     46static inline bool clk_master_ready(struct clk_master *master)
     47{
     48	unsigned int bit = master->id ? AT91_PMC_MCKXRDY : AT91_PMC_MCKRDY;
     49	unsigned int status;
     50
     51	regmap_read(master->regmap, AT91_PMC_SR, &status);
     52
     53	return !!(status & bit);
     54}
     55
     56static int clk_master_prepare(struct clk_hw *hw)
     57{
     58	struct clk_master *master = to_clk_master(hw);
     59	unsigned long flags;
     60
     61	spin_lock_irqsave(master->lock, flags);
     62
     63	while (!clk_master_ready(master))
     64		cpu_relax();
     65
     66	spin_unlock_irqrestore(master->lock, flags);
     67
     68	return 0;
     69}
     70
     71static int clk_master_is_prepared(struct clk_hw *hw)
     72{
     73	struct clk_master *master = to_clk_master(hw);
     74	unsigned long flags;
     75	bool status;
     76
     77	spin_lock_irqsave(master->lock, flags);
     78	status = clk_master_ready(master);
     79	spin_unlock_irqrestore(master->lock, flags);
     80
     81	return status;
     82}
     83
     84static unsigned long clk_master_div_recalc_rate(struct clk_hw *hw,
     85						unsigned long parent_rate)
     86{
     87	u8 div;
     88	unsigned long flags, rate = parent_rate;
     89	struct clk_master *master = to_clk_master(hw);
     90	const struct clk_master_layout *layout = master->layout;
     91	const struct clk_master_characteristics *characteristics =
     92						master->characteristics;
     93	unsigned int mckr;
     94
     95	spin_lock_irqsave(master->lock, flags);
     96	regmap_read(master->regmap, master->layout->offset, &mckr);
     97	spin_unlock_irqrestore(master->lock, flags);
     98
     99	mckr &= layout->mask;
    100
    101	div = (mckr >> MASTER_DIV_SHIFT) & MASTER_DIV_MASK;
    102
    103	rate /= characteristics->divisors[div];
    104
    105	if (rate < characteristics->output.min)
    106		pr_warn("master clk div is underclocked");
    107	else if (rate > characteristics->output.max)
    108		pr_warn("master clk div is overclocked");
    109
    110	return rate;
    111}
    112
    113static int clk_master_div_save_context(struct clk_hw *hw)
    114{
    115	struct clk_master *master = to_clk_master(hw);
    116	struct clk_hw *parent_hw = clk_hw_get_parent(hw);
    117	unsigned long flags;
    118	unsigned int mckr, div;
    119
    120	spin_lock_irqsave(master->lock, flags);
    121	regmap_read(master->regmap, master->layout->offset, &mckr);
    122	spin_unlock_irqrestore(master->lock, flags);
    123
    124	mckr &= master->layout->mask;
    125	div = (mckr >> MASTER_DIV_SHIFT) & MASTER_DIV_MASK;
    126	div = master->characteristics->divisors[div];
    127
    128	master->pms.parent_rate = clk_hw_get_rate(parent_hw);
    129	master->pms.rate = DIV_ROUND_CLOSEST(master->pms.parent_rate, div);
    130
    131	return 0;
    132}
    133
    134static void clk_master_div_restore_context(struct clk_hw *hw)
    135{
    136	struct clk_master *master = to_clk_master(hw);
    137	unsigned long flags;
    138	unsigned int mckr;
    139	u8 div;
    140
    141	spin_lock_irqsave(master->lock, flags);
    142	regmap_read(master->regmap, master->layout->offset, &mckr);
    143	spin_unlock_irqrestore(master->lock, flags);
    144
    145	mckr &= master->layout->mask;
    146	div = (mckr >> MASTER_DIV_SHIFT) & MASTER_DIV_MASK;
    147	div = master->characteristics->divisors[div];
    148
    149	if (div != DIV_ROUND_CLOSEST(master->pms.parent_rate, master->pms.rate))
    150		pr_warn("MCKR DIV not configured properly by firmware!\n");
    151}
    152
    153static const struct clk_ops master_div_ops = {
    154	.prepare = clk_master_prepare,
    155	.is_prepared = clk_master_is_prepared,
    156	.recalc_rate = clk_master_div_recalc_rate,
    157	.save_context = clk_master_div_save_context,
    158	.restore_context = clk_master_div_restore_context,
    159};
    160
    161/* This function must be called with lock acquired. */
    162static int clk_master_div_set(struct clk_master *master,
    163			      unsigned long parent_rate, int div)
    164{
    165	const struct clk_master_characteristics *characteristics =
    166						master->characteristics;
    167	unsigned long rate = parent_rate;
    168	unsigned int max_div = 0, div_index = 0, max_div_index = 0;
    169	unsigned int i, mckr, tmp;
    170	int ret;
    171
    172	for (i = 0; i < ARRAY_SIZE(characteristics->divisors); i++) {
    173		if (!characteristics->divisors[i])
    174			break;
    175
    176		if (div == characteristics->divisors[i])
    177			div_index = i;
    178
    179		if (max_div < characteristics->divisors[i]) {
    180			max_div = characteristics->divisors[i];
    181			max_div_index = i;
    182		}
    183	}
    184
    185	if (div > max_div)
    186		div_index = max_div_index;
    187
    188	ret = regmap_read(master->regmap, master->layout->offset, &mckr);
    189	if (ret)
    190		return ret;
    191
    192	mckr &= master->layout->mask;
    193	tmp = (mckr >> MASTER_DIV_SHIFT) & MASTER_DIV_MASK;
    194	if (tmp == div_index)
    195		return 0;
    196
    197	rate /= characteristics->divisors[div_index];
    198	if (rate < characteristics->output.min)
    199		pr_warn("master clk div is underclocked");
    200	else if (rate > characteristics->output.max)
    201		pr_warn("master clk div is overclocked");
    202
    203	mckr &= ~(MASTER_DIV_MASK << MASTER_DIV_SHIFT);
    204	mckr |= (div_index << MASTER_DIV_SHIFT);
    205	ret = regmap_write(master->regmap, master->layout->offset, mckr);
    206	if (ret)
    207		return ret;
    208
    209	while (!clk_master_ready(master))
    210		cpu_relax();
    211
    212	master->div = characteristics->divisors[div_index];
    213
    214	return 0;
    215}
    216
    217static unsigned long clk_master_div_recalc_rate_chg(struct clk_hw *hw,
    218						    unsigned long parent_rate)
    219{
    220	struct clk_master *master = to_clk_master(hw);
    221
    222	return DIV_ROUND_CLOSEST_ULL(parent_rate, master->div);
    223}
    224
    225static void clk_master_div_restore_context_chg(struct clk_hw *hw)
    226{
    227	struct clk_master *master = to_clk_master(hw);
    228	unsigned long flags;
    229	int ret;
    230
    231	spin_lock_irqsave(master->lock, flags);
    232	ret = clk_master_div_set(master, master->pms.parent_rate,
    233				 DIV_ROUND_CLOSEST(master->pms.parent_rate,
    234						   master->pms.rate));
    235	spin_unlock_irqrestore(master->lock, flags);
    236	if (ret)
    237		pr_warn("Failed to restore MCK DIV clock\n");
    238}
    239
    240static const struct clk_ops master_div_ops_chg = {
    241	.prepare = clk_master_prepare,
    242	.is_prepared = clk_master_is_prepared,
    243	.recalc_rate = clk_master_div_recalc_rate_chg,
    244	.save_context = clk_master_div_save_context,
    245	.restore_context = clk_master_div_restore_context_chg,
    246};
    247
    248static int clk_master_div_notifier_fn(struct notifier_block *notifier,
    249				      unsigned long code, void *data)
    250{
    251	const struct clk_master_characteristics *characteristics =
    252						master_div->characteristics;
    253	struct clk_notifier_data *cnd = data;
    254	unsigned long flags, new_parent_rate, new_rate;
    255	unsigned int mckr, div, new_div = 0;
    256	int ret, i;
    257	long tmp_diff;
    258	long best_diff = -1;
    259
    260	spin_lock_irqsave(master_div->lock, flags);
    261	switch (code) {
    262	case PRE_RATE_CHANGE:
    263		/*
    264		 * We want to avoid any overclocking of MCK DIV domain. To do
    265		 * this we set a safe divider (the underclocking is not of
    266		 * interest as we can go as low as 32KHz). The relation
    267		 * b/w this clock and its parents are as follows:
    268		 *
    269		 * FRAC PLL -> DIV PLL -> MCK DIV
    270		 *
    271		 * With the proper safe divider we should be good even with FRAC
    272		 * PLL at its maximum value.
    273		 */
    274		ret = regmap_read(master_div->regmap, master_div->layout->offset,
    275				  &mckr);
    276		if (ret) {
    277			ret = NOTIFY_STOP_MASK;
    278			goto unlock;
    279		}
    280
    281		mckr &= master_div->layout->mask;
    282		div = (mckr >> MASTER_DIV_SHIFT) & MASTER_DIV_MASK;
    283
    284		/* Switch to safe divider. */
    285		clk_master_div_set(master_div,
    286				   cnd->old_rate * characteristics->divisors[div],
    287				   master_div->safe_div);
    288		break;
    289
    290	case POST_RATE_CHANGE:
    291		/*
    292		 * At this point we want to restore MCK DIV domain to its maximum
    293		 * allowed rate.
    294		 */
    295		ret = regmap_read(master_div->regmap, master_div->layout->offset,
    296				  &mckr);
    297		if (ret) {
    298			ret = NOTIFY_STOP_MASK;
    299			goto unlock;
    300		}
    301
    302		mckr &= master_div->layout->mask;
    303		div = (mckr >> MASTER_DIV_SHIFT) & MASTER_DIV_MASK;
    304		new_parent_rate = cnd->new_rate * characteristics->divisors[div];
    305
    306		for (i = 0; i < ARRAY_SIZE(characteristics->divisors); i++) {
    307			if (!characteristics->divisors[i])
    308				break;
    309
    310			new_rate = DIV_ROUND_CLOSEST_ULL(new_parent_rate,
    311							 characteristics->divisors[i]);
    312
    313			tmp_diff = characteristics->output.max - new_rate;
    314			if (tmp_diff < 0)
    315				continue;
    316
    317			if (best_diff < 0 || best_diff > tmp_diff) {
    318				new_div = characteristics->divisors[i];
    319				best_diff = tmp_diff;
    320			}
    321
    322			if (!tmp_diff)
    323				break;
    324		}
    325
    326		if (!new_div) {
    327			ret = NOTIFY_STOP_MASK;
    328			goto unlock;
    329		}
    330
    331		/* Update the div to preserve MCK DIV clock rate. */
    332		clk_master_div_set(master_div, new_parent_rate,
    333				   new_div);
    334
    335		ret = NOTIFY_OK;
    336		break;
    337
    338	default:
    339		ret = NOTIFY_DONE;
    340		break;
    341	}
    342
    343unlock:
    344	spin_unlock_irqrestore(master_div->lock, flags);
    345
    346	return ret;
    347}
    348
    349static struct notifier_block clk_master_div_notifier = {
    350	.notifier_call = clk_master_div_notifier_fn,
    351};
    352
    353static void clk_sama7g5_master_best_diff(struct clk_rate_request *req,
    354					 struct clk_hw *parent,
    355					 unsigned long parent_rate,
    356					 long *best_rate,
    357					 long *best_diff,
    358					 u32 div)
    359{
    360	unsigned long tmp_rate, tmp_diff;
    361
    362	if (div == MASTER_PRES_MAX)
    363		tmp_rate = parent_rate / 3;
    364	else
    365		tmp_rate = parent_rate >> div;
    366
    367	tmp_diff = abs(req->rate - tmp_rate);
    368
    369	if (*best_diff < 0 || *best_diff >= tmp_diff) {
    370		*best_rate = tmp_rate;
    371		*best_diff = tmp_diff;
    372		req->best_parent_rate = parent_rate;
    373		req->best_parent_hw = parent;
    374	}
    375}
    376
    377static unsigned long clk_master_pres_recalc_rate(struct clk_hw *hw,
    378						 unsigned long parent_rate)
    379{
    380	struct clk_master *master = to_clk_master(hw);
    381	const struct clk_master_characteristics *characteristics =
    382						master->characteristics;
    383	unsigned long flags;
    384	unsigned int val, pres;
    385
    386	spin_lock_irqsave(master->lock, flags);
    387	regmap_read(master->regmap, master->layout->offset, &val);
    388	spin_unlock_irqrestore(master->lock, flags);
    389
    390	val &= master->layout->mask;
    391	pres = (val >> master->layout->pres_shift) & MASTER_PRES_MASK;
    392	if (pres == MASTER_PRES_MAX && characteristics->have_div3_pres)
    393		pres = 3;
    394	else
    395		pres = (1 << pres);
    396
    397	return DIV_ROUND_CLOSEST_ULL(parent_rate, pres);
    398}
    399
    400static u8 clk_master_pres_get_parent(struct clk_hw *hw)
    401{
    402	struct clk_master *master = to_clk_master(hw);
    403	unsigned long flags;
    404	unsigned int mckr;
    405
    406	spin_lock_irqsave(master->lock, flags);
    407	regmap_read(master->regmap, master->layout->offset, &mckr);
    408	spin_unlock_irqrestore(master->lock, flags);
    409
    410	mckr &= master->layout->mask;
    411
    412	return mckr & AT91_PMC_CSS;
    413}
    414
    415static int clk_master_pres_save_context(struct clk_hw *hw)
    416{
    417	struct clk_master *master = to_clk_master(hw);
    418	struct clk_hw *parent_hw = clk_hw_get_parent(hw);
    419	unsigned long flags;
    420	unsigned int val, pres;
    421
    422	spin_lock_irqsave(master->lock, flags);
    423	regmap_read(master->regmap, master->layout->offset, &val);
    424	spin_unlock_irqrestore(master->lock, flags);
    425
    426	val &= master->layout->mask;
    427	pres = (val >> master->layout->pres_shift) & MASTER_PRES_MASK;
    428	if (pres == MASTER_PRES_MAX && master->characteristics->have_div3_pres)
    429		pres = 3;
    430	else
    431		pres = (1 << pres);
    432
    433	master->pms.parent = val & AT91_PMC_CSS;
    434	master->pms.parent_rate = clk_hw_get_rate(parent_hw);
    435	master->pms.rate = DIV_ROUND_CLOSEST_ULL(master->pms.parent_rate, pres);
    436
    437	return 0;
    438}
    439
    440static void clk_master_pres_restore_context(struct clk_hw *hw)
    441{
    442	struct clk_master *master = to_clk_master(hw);
    443	unsigned long flags;
    444	unsigned int val, pres;
    445
    446	spin_lock_irqsave(master->lock, flags);
    447	regmap_read(master->regmap, master->layout->offset, &val);
    448	spin_unlock_irqrestore(master->lock, flags);
    449
    450	val &= master->layout->mask;
    451	pres = (val >> master->layout->pres_shift) & MASTER_PRES_MASK;
    452	if (pres == MASTER_PRES_MAX && master->characteristics->have_div3_pres)
    453		pres = 3;
    454	else
    455		pres = (1 << pres);
    456
    457	if (master->pms.rate !=
    458	    DIV_ROUND_CLOSEST_ULL(master->pms.parent_rate, pres) ||
    459	    (master->pms.parent != (val & AT91_PMC_CSS)))
    460		pr_warn("MCKR PRES was not configured properly by firmware!\n");
    461}
    462
    463static const struct clk_ops master_pres_ops = {
    464	.prepare = clk_master_prepare,
    465	.is_prepared = clk_master_is_prepared,
    466	.recalc_rate = clk_master_pres_recalc_rate,
    467	.get_parent = clk_master_pres_get_parent,
    468	.save_context = clk_master_pres_save_context,
    469	.restore_context = clk_master_pres_restore_context,
    470};
    471
    472static struct clk_hw * __init
    473at91_clk_register_master_internal(struct regmap *regmap,
    474		const char *name, int num_parents,
    475		const char **parent_names,
    476		const struct clk_master_layout *layout,
    477		const struct clk_master_characteristics *characteristics,
    478		const struct clk_ops *ops, spinlock_t *lock, u32 flags)
    479{
    480	struct clk_master *master;
    481	struct clk_init_data init;
    482	struct clk_hw *hw;
    483	unsigned int mckr;
    484	unsigned long irqflags;
    485	int ret;
    486
    487	if (!name || !num_parents || !parent_names || !lock)
    488		return ERR_PTR(-EINVAL);
    489
    490	master = kzalloc(sizeof(*master), GFP_KERNEL);
    491	if (!master)
    492		return ERR_PTR(-ENOMEM);
    493
    494	init.name = name;
    495	init.ops = ops;
    496	init.parent_names = parent_names;
    497	init.num_parents = num_parents;
    498	init.flags = flags;
    499
    500	master->hw.init = &init;
    501	master->layout = layout;
    502	master->characteristics = characteristics;
    503	master->regmap = regmap;
    504	master->lock = lock;
    505
    506	if (ops == &master_div_ops_chg) {
    507		spin_lock_irqsave(master->lock, irqflags);
    508		regmap_read(master->regmap, master->layout->offset, &mckr);
    509		spin_unlock_irqrestore(master->lock, irqflags);
    510
    511		mckr &= layout->mask;
    512		mckr = (mckr >> MASTER_DIV_SHIFT) & MASTER_DIV_MASK;
    513		master->div = characteristics->divisors[mckr];
    514	}
    515
    516	hw = &master->hw;
    517	ret = clk_hw_register(NULL, &master->hw);
    518	if (ret) {
    519		kfree(master);
    520		hw = ERR_PTR(ret);
    521	}
    522
    523	return hw;
    524}
    525
    526struct clk_hw * __init
    527at91_clk_register_master_pres(struct regmap *regmap,
    528		const char *name, int num_parents,
    529		const char **parent_names,
    530		const struct clk_master_layout *layout,
    531		const struct clk_master_characteristics *characteristics,
    532		spinlock_t *lock)
    533{
    534	return at91_clk_register_master_internal(regmap, name, num_parents,
    535						 parent_names, layout,
    536						 characteristics,
    537						 &master_pres_ops,
    538						 lock, CLK_SET_RATE_GATE);
    539}
    540
    541struct clk_hw * __init
    542at91_clk_register_master_div(struct regmap *regmap,
    543		const char *name, const char *parent_name,
    544		const struct clk_master_layout *layout,
    545		const struct clk_master_characteristics *characteristics,
    546		spinlock_t *lock, u32 flags, u32 safe_div)
    547{
    548	const struct clk_ops *ops;
    549	struct clk_hw *hw;
    550
    551	if (flags & CLK_SET_RATE_GATE)
    552		ops = &master_div_ops;
    553	else
    554		ops = &master_div_ops_chg;
    555
    556	hw = at91_clk_register_master_internal(regmap, name, 1,
    557					       &parent_name, layout,
    558					       characteristics, ops,
    559					       lock, flags);
    560
    561	if (!IS_ERR(hw) && safe_div) {
    562		master_div = to_clk_master(hw);
    563		master_div->safe_div = safe_div;
    564		clk_notifier_register(hw->clk,
    565				      &clk_master_div_notifier);
    566	}
    567
    568	return hw;
    569}
    570
    571static unsigned long
    572clk_sama7g5_master_recalc_rate(struct clk_hw *hw,
    573			       unsigned long parent_rate)
    574{
    575	struct clk_master *master = to_clk_master(hw);
    576
    577	return DIV_ROUND_CLOSEST_ULL(parent_rate, (1 << master->div));
    578}
    579
    580static int clk_sama7g5_master_determine_rate(struct clk_hw *hw,
    581					     struct clk_rate_request *req)
    582{
    583	struct clk_master *master = to_clk_master(hw);
    584	struct clk_rate_request req_parent = *req;
    585	struct clk_hw *parent;
    586	long best_rate = LONG_MIN, best_diff = LONG_MIN;
    587	unsigned long parent_rate;
    588	unsigned int div, i;
    589
    590	/* First: check the dividers of MCR. */
    591	for (i = 0; i < clk_hw_get_num_parents(hw); i++) {
    592		parent = clk_hw_get_parent_by_index(hw, i);
    593		if (!parent)
    594			continue;
    595
    596		parent_rate = clk_hw_get_rate(parent);
    597		if (!parent_rate)
    598			continue;
    599
    600		for (div = 0; div < MASTER_PRES_MAX + 1; div++) {
    601			clk_sama7g5_master_best_diff(req, parent, parent_rate,
    602						     &best_rate, &best_diff,
    603						     div);
    604			if (!best_diff)
    605				break;
    606		}
    607
    608		if (!best_diff)
    609			break;
    610	}
    611
    612	/* Second: try to request rate form changeable parent. */
    613	if (master->chg_pid < 0)
    614		goto end;
    615
    616	parent = clk_hw_get_parent_by_index(hw, master->chg_pid);
    617	if (!parent)
    618		goto end;
    619
    620	for (div = 0; div < MASTER_PRES_MAX + 1; div++) {
    621		if (div == MASTER_PRES_MAX)
    622			req_parent.rate = req->rate * 3;
    623		else
    624			req_parent.rate = req->rate << div;
    625
    626		if (__clk_determine_rate(parent, &req_parent))
    627			continue;
    628
    629		clk_sama7g5_master_best_diff(req, parent, req_parent.rate,
    630					     &best_rate, &best_diff, div);
    631
    632		if (!best_diff)
    633			break;
    634	}
    635
    636end:
    637	pr_debug("MCK: %s, best_rate = %ld, parent clk: %s @ %ld\n",
    638		 __func__, best_rate,
    639		 __clk_get_name((req->best_parent_hw)->clk),
    640		req->best_parent_rate);
    641
    642	if (best_rate < 0)
    643		return -EINVAL;
    644
    645	req->rate = best_rate;
    646
    647	return 0;
    648}
    649
    650static u8 clk_sama7g5_master_get_parent(struct clk_hw *hw)
    651{
    652	struct clk_master *master = to_clk_master(hw);
    653	unsigned long flags;
    654	u8 index;
    655
    656	spin_lock_irqsave(master->lock, flags);
    657	index = clk_mux_val_to_index(&master->hw, master->mux_table, 0,
    658				     master->parent);
    659	spin_unlock_irqrestore(master->lock, flags);
    660
    661	return index;
    662}
    663
    664static int clk_sama7g5_master_set_parent(struct clk_hw *hw, u8 index)
    665{
    666	struct clk_master *master = to_clk_master(hw);
    667	unsigned long flags;
    668
    669	if (index >= clk_hw_get_num_parents(hw))
    670		return -EINVAL;
    671
    672	spin_lock_irqsave(master->lock, flags);
    673	master->parent = clk_mux_index_to_val(master->mux_table, 0, index);
    674	spin_unlock_irqrestore(master->lock, flags);
    675
    676	return 0;
    677}
    678
    679static void clk_sama7g5_master_set(struct clk_master *master,
    680				   unsigned int status)
    681{
    682	unsigned long flags;
    683	unsigned int val, cparent;
    684	unsigned int enable = status ? AT91_PMC_MCR_V2_EN : 0;
    685	unsigned int parent = master->parent << PMC_MCR_CSS_SHIFT;
    686	unsigned int div = master->div << MASTER_DIV_SHIFT;
    687
    688	spin_lock_irqsave(master->lock, flags);
    689
    690	regmap_write(master->regmap, AT91_PMC_MCR_V2,
    691		     AT91_PMC_MCR_V2_ID(master->id));
    692	regmap_read(master->regmap, AT91_PMC_MCR_V2, &val);
    693	regmap_update_bits(master->regmap, AT91_PMC_MCR_V2,
    694			   enable | AT91_PMC_MCR_V2_CSS | AT91_PMC_MCR_V2_DIV |
    695			   AT91_PMC_MCR_V2_CMD | AT91_PMC_MCR_V2_ID_MSK,
    696			   enable | parent | div | AT91_PMC_MCR_V2_CMD |
    697			   AT91_PMC_MCR_V2_ID(master->id));
    698
    699	cparent = (val & AT91_PMC_MCR_V2_CSS) >> PMC_MCR_CSS_SHIFT;
    700
    701	/* Wait here only if parent is being changed. */
    702	while ((cparent != master->parent) && !clk_master_ready(master))
    703		cpu_relax();
    704
    705	spin_unlock_irqrestore(master->lock, flags);
    706}
    707
    708static int clk_sama7g5_master_enable(struct clk_hw *hw)
    709{
    710	struct clk_master *master = to_clk_master(hw);
    711
    712	clk_sama7g5_master_set(master, 1);
    713
    714	return 0;
    715}
    716
    717static void clk_sama7g5_master_disable(struct clk_hw *hw)
    718{
    719	struct clk_master *master = to_clk_master(hw);
    720	unsigned long flags;
    721
    722	spin_lock_irqsave(master->lock, flags);
    723
    724	regmap_write(master->regmap, AT91_PMC_MCR_V2, master->id);
    725	regmap_update_bits(master->regmap, AT91_PMC_MCR_V2,
    726			   AT91_PMC_MCR_V2_EN | AT91_PMC_MCR_V2_CMD |
    727			   AT91_PMC_MCR_V2_ID_MSK,
    728			   AT91_PMC_MCR_V2_CMD |
    729			   AT91_PMC_MCR_V2_ID(master->id));
    730
    731	spin_unlock_irqrestore(master->lock, flags);
    732}
    733
    734static int clk_sama7g5_master_is_enabled(struct clk_hw *hw)
    735{
    736	struct clk_master *master = to_clk_master(hw);
    737	unsigned long flags;
    738	unsigned int val;
    739
    740	spin_lock_irqsave(master->lock, flags);
    741
    742	regmap_write(master->regmap, AT91_PMC_MCR_V2, master->id);
    743	regmap_read(master->regmap, AT91_PMC_MCR_V2, &val);
    744
    745	spin_unlock_irqrestore(master->lock, flags);
    746
    747	return !!(val & AT91_PMC_MCR_V2_EN);
    748}
    749
    750static int clk_sama7g5_master_set_rate(struct clk_hw *hw, unsigned long rate,
    751				       unsigned long parent_rate)
    752{
    753	struct clk_master *master = to_clk_master(hw);
    754	unsigned long div, flags;
    755
    756	div = DIV_ROUND_CLOSEST(parent_rate, rate);
    757	if ((div > (1 << (MASTER_PRES_MAX - 1))) || (div & (div - 1)))
    758		return -EINVAL;
    759
    760	if (div == 3)
    761		div = MASTER_PRES_MAX;
    762	else if (div)
    763		div = ffs(div) - 1;
    764
    765	spin_lock_irqsave(master->lock, flags);
    766	master->div = div;
    767	spin_unlock_irqrestore(master->lock, flags);
    768
    769	return 0;
    770}
    771
    772static int clk_sama7g5_master_save_context(struct clk_hw *hw)
    773{
    774	struct clk_master *master = to_clk_master(hw);
    775
    776	master->pms.status = clk_sama7g5_master_is_enabled(hw);
    777
    778	return 0;
    779}
    780
    781static void clk_sama7g5_master_restore_context(struct clk_hw *hw)
    782{
    783	struct clk_master *master = to_clk_master(hw);
    784
    785	if (master->pms.status)
    786		clk_sama7g5_master_set(master, master->pms.status);
    787}
    788
    789static const struct clk_ops sama7g5_master_ops = {
    790	.enable = clk_sama7g5_master_enable,
    791	.disable = clk_sama7g5_master_disable,
    792	.is_enabled = clk_sama7g5_master_is_enabled,
    793	.recalc_rate = clk_sama7g5_master_recalc_rate,
    794	.determine_rate = clk_sama7g5_master_determine_rate,
    795	.set_rate = clk_sama7g5_master_set_rate,
    796	.get_parent = clk_sama7g5_master_get_parent,
    797	.set_parent = clk_sama7g5_master_set_parent,
    798	.save_context = clk_sama7g5_master_save_context,
    799	.restore_context = clk_sama7g5_master_restore_context,
    800};
    801
    802struct clk_hw * __init
    803at91_clk_sama7g5_register_master(struct regmap *regmap,
    804				 const char *name, int num_parents,
    805				 const char **parent_names,
    806				 u32 *mux_table,
    807				 spinlock_t *lock, u8 id,
    808				 bool critical, int chg_pid)
    809{
    810	struct clk_master *master;
    811	struct clk_hw *hw;
    812	struct clk_init_data init;
    813	unsigned long flags;
    814	unsigned int val;
    815	int ret;
    816
    817	if (!name || !num_parents || !parent_names || !mux_table ||
    818	    !lock || id > MASTER_MAX_ID)
    819		return ERR_PTR(-EINVAL);
    820
    821	master = kzalloc(sizeof(*master), GFP_KERNEL);
    822	if (!master)
    823		return ERR_PTR(-ENOMEM);
    824
    825	init.name = name;
    826	init.ops = &sama7g5_master_ops;
    827	init.parent_names = parent_names;
    828	init.num_parents = num_parents;
    829	init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE;
    830	if (chg_pid >= 0)
    831		init.flags |= CLK_SET_RATE_PARENT;
    832	if (critical)
    833		init.flags |= CLK_IS_CRITICAL;
    834
    835	master->hw.init = &init;
    836	master->regmap = regmap;
    837	master->id = id;
    838	master->chg_pid = chg_pid;
    839	master->lock = lock;
    840	master->mux_table = mux_table;
    841
    842	spin_lock_irqsave(master->lock, flags);
    843	regmap_write(master->regmap, AT91_PMC_MCR_V2, master->id);
    844	regmap_read(master->regmap, AT91_PMC_MCR_V2, &val);
    845	master->parent = (val & AT91_PMC_MCR_V2_CSS) >> PMC_MCR_CSS_SHIFT;
    846	master->div = (val & AT91_PMC_MCR_V2_DIV) >> MASTER_DIV_SHIFT;
    847	spin_unlock_irqrestore(master->lock, flags);
    848
    849	hw = &master->hw;
    850	ret = clk_hw_register(NULL, &master->hw);
    851	if (ret) {
    852		kfree(master);
    853		hw = ERR_PTR(ret);
    854	}
    855
    856	return hw;
    857}
    858
    859const struct clk_master_layout at91rm9200_master_layout = {
    860	.mask = 0x31F,
    861	.pres_shift = 2,
    862	.offset = AT91_PMC_MCKR,
    863};
    864
    865const struct clk_master_layout at91sam9x5_master_layout = {
    866	.mask = 0x373,
    867	.pres_shift = 4,
    868	.offset = AT91_PMC_MCKR,
    869};