aboutsummaryrefslogtreecommitdiff
path: root/drivers/clk/imx/clk-pllv4.c
blob: d7e62c3620d36941f498e3519bc2f03e203a26a3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (C) 2016 Freescale Semiconductor, Inc.
 * Copyright 2017~2018 NXP
 *
 * Author: Dong Aisheng <aisheng.dong@nxp.com>
 *
 */

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

#include "clk.h"

/* PLL Control Status Register (xPLLCSR) */
#define PLL_CSR_OFFSET		0x0
#define PLL_VLD			BIT(24)
#define PLL_EN			BIT(0)

/* PLL Configuration Register (xPLLCFG) */
#define PLL_CFG_OFFSET		0x08
#define BP_PLL_MULT		16
#define BM_PLL_MULT		(0x7f << 16)

/* PLL Numerator Register (xPLLNUM) */
#define PLL_NUM_OFFSET		0x10

/* PLL Denominator Register (xPLLDENOM) */
#define PLL_DENOM_OFFSET	0x14

#define MAX_MFD			0x3fffffff
#define DEFAULT_MFD		1000000

struct clk_pllv4 {
	struct clk_hw	hw;
	void __iomem	*base;
};

/* Valid PLL MULT Table */
static const int pllv4_mult_table[] = {33, 27, 22, 20, 17, 16};

#define to_clk_pllv4(__hw) container_of(__hw, struct clk_pllv4, hw)

#define LOCK_TIMEOUT_US		USEC_PER_MSEC

static inline int clk_pllv4_wait_lock(struct clk_pllv4 *pll)
{
	u32 csr;

	return readl_poll_timeout(pll->base  + PLL_CSR_OFFSET,
				  csr, csr & PLL_VLD, 0, LOCK_TIMEOUT_US);
}

static int clk_pllv4_is_enabled(struct clk_hw *hw)
{
	struct clk_pllv4 *pll = to_clk_pllv4(hw);

	if (readl_relaxed(pll->base) & PLL_EN)
		return 1;

	return 0;
}

static unsigned long clk_pllv4_recalc_rate(struct clk_hw *hw,
					   unsigned long parent_rate)
{
	struct clk_pllv4 *pll = to_clk_pllv4(hw);
	u32 mult, mfn, mfd;
	u64 temp64;

	mult = readl_relaxed(pll->base + PLL_CFG_OFFSET);
	mult &= BM_PLL_MULT;
	mult >>= BP_PLL_MULT;

	mfn = readl_relaxed(pll->base + PLL_NUM_OFFSET);
	mfd = readl_relaxed(pll->base + PLL_DENOM_OFFSET);
	temp64 = parent_rate;
	temp64 *= mfn;
	do_div(temp64, mfd);

	return (parent_rate * mult) + (u32)temp64;
}

static long clk_pllv4_round_rate(struct clk_hw *hw, unsigned long rate,
				 unsigned long *prate)
{
	unsigned long parent_rate = *prate;
	unsigned long round_rate, i;
	u32 mfn, mfd = DEFAULT_MFD;
	bool found = false;
	u64 temp64;

	for (i = 0; i < ARRAY_SIZE(pllv4_mult_table); i++) {
		round_rate = parent_rate * pllv4_mult_table[i];
		if (rate >= round_rate) {
			found = true;
			break;
		}
	}

	if (!found) {
		pr_warn("%s: unable to round rate %lu, parent rate %lu\n",
			clk_hw_get_name(hw), rate, parent_rate);
		return 0;
	}

	if (parent_rate <= MAX_MFD)
		mfd = parent_rate;

	temp64 = (u64)(rate - round_rate);
	temp64 *= mfd;
	do_div(temp64, parent_rate);
	mfn = temp64;

	/*
	 * NOTE: The value of numerator must always be configured to be
	 * less than the value of the denominator. If we can't get a proper
	 * pair of mfn/mfd, we simply return the round_rate without using
	 * the frac part.
	 */
	if (mfn >= mfd)
		return round_rate;

	temp64 = (u64)parent_rate;
	temp64 *= mfn;
	do_div(temp64, mfd);

	return round_rate + (u32)temp64;
}

static bool clk_pllv4_is_valid_mult(unsigned int mult)
{
	int i;

	/* check if mult is in valid MULT table */
	for (i = 0; i < ARRAY_SIZE(pllv4_mult_table); i++) {
		if (pllv4_mult_table[i] == mult)
			return true;
	}

	return false;
}

static int clk_pllv4_set_rate(struct clk_hw *hw, unsigned long rate,
			      unsigned long parent_rate)
{
	struct clk_pllv4 *pll = to_clk_pllv4(hw);
	u32 val, mult, mfn, mfd = DEFAULT_MFD;
	u64 temp64;

	mult = rate / parent_rate;

	if (!clk_pllv4_is_valid_mult(mult))
		return -EINVAL;

	if (parent_rate <= MAX_MFD)
		mfd = parent_rate;

	temp64 = (u64)(rate - mult * parent_rate);
	temp64 *= mfd;
	do_div(temp64, parent_rate);
	mfn = temp64;

	val = readl_relaxed(pll->base + PLL_CFG_OFFSET);
	val &= ~BM_PLL_MULT;
	val |= mult << BP_PLL_MULT;
	writel_relaxed(val, pll->base + PLL_CFG_OFFSET);

	writel_relaxed(mfn, pll->base + PLL_NUM_OFFSET);
	writel_relaxed(mfd, pll->base + PLL_DENOM_OFFSET);

	return 0;
}

static int clk_pllv4_enable(struct clk_hw *hw)
{
	u32 val;
	struct clk_pllv4 *pll = to_clk_pllv4(hw);

	val = readl_relaxed(pll->base);
	val |= PLL_EN;
	writel_relaxed(val, pll->base);

	return clk_pllv4_wait_lock(pll);
}

static void clk_pllv4_disable(struct clk_hw *hw)
{
	u32 val;
	struct clk_pllv4 *pll = to_clk_pllv4(hw);

	val = readl_relaxed(pll->base);
	val &= ~PLL_EN;
	writel_relaxed(val, pll->base);
}

static const struct clk_ops clk_pllv4_ops = {
	.recalc_rate	= clk_pllv4_recalc_rate,
	.round_rate	= clk_pllv4_round_rate,
	.set_rate	= clk_pllv4_set_rate,
	.enable		= clk_pllv4_enable,
	.disable	= clk_pllv4_disable,
	.is_enabled	= clk_pllv4_is_enabled,
};

struct clk_hw *imx_clk_pllv4(const char *name, const char *parent_name,
			  void __iomem *base)
{
	struct clk_pllv4 *pll;
	struct clk_hw *hw;
	struct clk_init_data init;
	int ret;

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

	pll->base = base;

	init.name = name;
	init.ops = &clk_pllv4_ops;
	init.parent_names = &parent_name;
	init.num_parents = 1;
	init.flags = CLK_SET_RATE_GATE;

	pll->hw.init = &init;

	hw = &pll->hw;
	ret = clk_hw_register(NULL, hw);
	if (ret) {
		kfree(pll);
		hw = ERR_PTR(ret);
	}

	return hw;
}