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gerrit.devboardsforandroid.linaro.org / platform / external / u-boot / 312f2c5b14fa3fac1cbf942fad3a08ab6358d025 / . / drivers / clk / at91 / clk-usb.c
blob: 24af183b55066ed0722a386e92b5523349e3859a [file] [log] [blame]
Tom Rini83d290c2018-05-06 17:58:06 -0400[diff] [blame]1// SPDX-License-Identifier: GPL-2.0+
Wenyou Yangcb0cb1b2018-02-09 11:34:50 +0800[diff] [blame]2/*
3 * Copyright (C) 2018 Microhip / Atmel Corporation
4 * Wenyou.Yang <wenyou.yang@microchip.com>
Wenyou Yangcb0cb1b2018-02-09 11:34:50 +0800[diff] [blame]5 */
6
7#include <common.h>
8#include <clk-uclass.h>
9#include <dm/device.h>
10#include <linux/io.h>
11#include <mach/at91_pmc.h>
12#include "pmc.h"
13
14DECLARE_GLOBAL_DATA_PTR;
15
16#define AT91_USB_CLK_SOURCE_MAX 2
17#define AT91_USB_CLK_MAX_DIV 15
18
19struct at91_usb_clk_priv {
20 u32 num_clksource;
21};
22
23static ulong at91_usb_clk_get_rate(struct clk *clk)
24{
25 struct pmc_platdata *plat = dev_get_platdata(clk->dev);
26 struct at91_pmc *pmc = plat->reg_base;
27 struct clk source;
28 u32 tmp, usbdiv;
29 u8 source_index;
30 int ret;
31
32 tmp = readl(&pmc->pcr);
33 source_index = (tmp >> AT91_PMC_USB_USBS_OFFSET) &
34 AT91_PMC_USB_USBS_MASK;
35 usbdiv = (tmp >> AT91_PMC_USB_DIV_OFFSET) & AT91_PMC_USB_DIV_MASK;
36
37 ret = clk_get_by_index(clk->dev, source_index, &source);
38 if (ret)
39 return 0;
40
41 return clk_get_rate(&source) / (usbdiv + 1);
42}
43
44static ulong at91_usb_clk_set_rate(struct clk *clk, ulong rate)
45{
46 struct pmc_platdata *plat = dev_get_platdata(clk->dev);
47 struct at91_pmc *pmc = plat->reg_base;
48 struct at91_usb_clk_priv *priv = dev_get_priv(clk->dev);
49 struct clk source, best_source;
50 ulong tmp_rate, best_rate = rate, source_rate;
51 int tmp_diff, best_diff = -1;
52 u32 div, best_div = 0;
53 u8 best_source_index = 0;
54 u8 i;
55 u32 tmp;
56 int ret;
57
58 for (i = 0; i < priv->num_clksource; i++) {
59 ret = clk_get_by_index(clk->dev, i, &source);
60 if (ret)
61 return ret;
62
63 source_rate = clk_get_rate(&source);
64 if (IS_ERR_VALUE(source_rate))
65 return source_rate;
66
67 for (div = 1; div < AT91_USB_CLK_MAX_DIV + 2; div++) {
68 tmp_rate = DIV_ROUND_CLOSEST(source_rate, div);
69 tmp_diff = abs(rate - tmp_rate);
70
71 if (best_diff < 0 || best_diff > tmp_diff) {
72 best_rate = tmp_rate;
73 best_diff = tmp_diff;
74
75 best_div = div - 1;
76 best_source = source;
77 best_source_index = i;
78 }
79
80 if (!best_diff || tmp_rate < rate)
81 break;
82 }
83
84 if (!best_diff)
85 break;
86 }
87
88 debug("AT91 USB: best sourc: %s, best_rate = %ld, best_div = %d\n",
89 best_source.dev->name, best_rate, best_div);
90
91 ret = clk_enable(&best_source);
92 if (ret)
93 return ret;
94
95 tmp = AT91_PMC_USB_USBS_(best_source_index) |
96 AT91_PMC_USB_DIV_(best_div);
97 writel(tmp, &pmc->usb);
98
99 return 0;
100}
101
102static struct clk_ops at91_usb_clk_ops = {
103 .get_rate = at91_usb_clk_get_rate,
104 .set_rate = at91_usb_clk_set_rate,
105};
106
107static int at91_usb_clk_ofdata_to_platdata(struct udevice *dev)
108{
109 struct at91_usb_clk_priv *priv = dev_get_priv(dev);
110 u32 cells[AT91_USB_CLK_SOURCE_MAX];
111 u32 num_clksource;
112
113 num_clksource = fdtdec_get_int_array_count(gd->fdt_blob,
114 dev_of_offset(dev),
115 "clocks", cells,
116 AT91_USB_CLK_SOURCE_MAX);
117
118 if (!num_clksource)
119 return -1;
120
121 priv->num_clksource = num_clksource;
122
123 return 0;
124}
125
126static int at91_usb_clk_probe(struct udevice *dev)
127{
128 return at91_pmc_core_probe(dev);
129}
130
131static const struct udevice_id at91_usb_clk_match[] = {
132 { .compatible = "atmel,at91sam9x5-clk-usb" },
133 {}
134};
135
136U_BOOT_DRIVER(at91_usb_clk) = {
137 .name = "at91-usb-clk",
138 .id = UCLASS_CLK,
139 .of_match = at91_usb_clk_match,
140 .probe = at91_usb_clk_probe,
141 .ofdata_to_platdata = at91_usb_clk_ofdata_to_platdata,
142 .priv_auto_alloc_size = sizeof(struct at91_usb_clk_priv),
143 .platdata_auto_alloc_size = sizeof(struct pmc_platdata),
144 .ops = &at91_usb_clk_ops,
145};