summaryrefslogtreecommitdiff
path: root/drivers/clk/at91/clk-utmi.c
blob: 54970b949fac05efe5776ae289c4744fcafbf12f (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
/*
 * Copyright (C) 2016 Atmel Corporation
 *               Wenyou.Yang <wenyou.yang@atmel.com>
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

#include <common.h>
#include <clk-uclass.h>
#include <dm.h>
#include <syscon.h>
#include <linux/io.h>
#include <mach/at91_pmc.h>
#include <mach/sama5_sfr.h>
#include "pmc.h"

/*
 * The purpose of this clock is to generate a 480 MHz signal. A different
 * rate can't be configured.
 */
#define UTMI_RATE	480000000

static int utmi_clk_enable(struct clk *clk)
{
	struct pmc_platdata *plat = dev_get_platdata(clk->dev);
	struct at91_pmc *pmc = plat->reg_base;
	struct clk clk_dev;
	ulong clk_rate;
	u32 utmi_ref_clk_freq;
	u32 tmp;
	int err;

	if (readl(&pmc->sr) & AT91_PMC_LOCKU)
		return 0;

	/*
	 * If mainck rate is different from 12 MHz, we have to configure the
	 * FREQ field of the SFR_UTMICKTRIM register to generate properly
	 * the utmi clock.
	 */
	err = clk_get_by_index(clk->dev, 0, &clk_dev);
	if (err)
		return -EINVAL;

	clk_rate = clk_get_rate(&clk_dev);
	switch (clk_rate) {
	case 12000000:
		utmi_ref_clk_freq = 0;
		break;
	case 16000000:
		utmi_ref_clk_freq = 1;
		break;
	case 24000000:
		utmi_ref_clk_freq = 2;
		break;
	/*
	 * Not supported on SAMA5D2 but it's not an issue since MAINCK
	 * maximum value is 24 MHz.
	 */
	case 48000000:
		utmi_ref_clk_freq = 3;
		break;
	default:
		printf("UTMICK: unsupported mainck rate\n");
		return -EINVAL;
	}

	if (plat->regmap_sfr) {
		err = regmap_read(plat->regmap_sfr, AT91_SFR_UTMICKTRIM, &tmp);
		if (err)
			return -EINVAL;

		tmp &= ~AT91_UTMICKTRIM_FREQ;
		tmp |= utmi_ref_clk_freq;
		err = regmap_write(plat->regmap_sfr, AT91_SFR_UTMICKTRIM, tmp);
		if (err)
			return -EINVAL;
	} else if (utmi_ref_clk_freq) {
		printf("UTMICK: sfr node required\n");
		return -EINVAL;
	}

	tmp = readl(&pmc->uckr);
	tmp |= AT91_PMC_UPLLEN |
	       AT91_PMC_UPLLCOUNT |
	       AT91_PMC_BIASEN;
	writel(tmp, &pmc->uckr);

	while (!(readl(&pmc->sr) & AT91_PMC_LOCKU))
		;

	return 0;
}

static ulong utmi_clk_get_rate(struct clk *clk)
{
	/* UTMI clk rate is fixed. */
	return UTMI_RATE;
}

static struct clk_ops utmi_clk_ops = {
	.enable = utmi_clk_enable,
	.get_rate = utmi_clk_get_rate,
};

static int utmi_clk_ofdata_to_platdata(struct udevice *dev)
{
	struct pmc_platdata *plat = dev_get_platdata(dev);
	struct udevice *syscon;

	uclass_get_device_by_phandle(UCLASS_SYSCON, dev,
				     "regmap-sfr", &syscon);

	if (syscon)
		plat->regmap_sfr = syscon_get_regmap(syscon);

	return 0;
}

static int utmi_clk_probe(struct udevice *dev)
{
	return at91_pmc_core_probe(dev);
}

static const struct udevice_id utmi_clk_match[] = {
	{ .compatible = "atmel,at91sam9x5-clk-utmi" },
	{}
};

U_BOOT_DRIVER(at91sam9x5_utmi_clk) = {
	.name = "at91sam9x5-utmi-clk",
	.id = UCLASS_CLK,
	.of_match = utmi_clk_match,
	.probe = utmi_clk_probe,
	.ofdata_to_platdata = utmi_clk_ofdata_to_platdata,
	.platdata_auto_alloc_size = sizeof(struct pmc_platdata),
	.ops = &utmi_clk_ops,
};