xref: /openbmc/u-boot/drivers/clk/at91/clk-utmi.c (revision a22bbfda)
1 /*
2  * Copyright (C) 2016 Atmel Corporation
3  *               Wenyou.Yang <wenyou.yang@atmel.com>
4  *
5  * SPDX-License-Identifier:	GPL-2.0+
6  */
7 
8 #include <common.h>
9 #include <clk-uclass.h>
10 #include <dm.h>
11 #include <linux/io.h>
12 #include <mach/at91_pmc.h>
13 #include "pmc.h"
14 
15 DECLARE_GLOBAL_DATA_PTR;
16 
17 #define UTMI_FIXED_MUL		40
18 
19 static int utmi_clk_enable(struct clk *clk)
20 {
21 	struct pmc_platdata *plat = dev_get_platdata(clk->dev);
22 	struct at91_pmc *pmc = plat->reg_base;
23 	u32 tmp;
24 
25 	if (readl(&pmc->sr) & AT91_PMC_LOCKU)
26 		return 0;
27 
28 	tmp = readl(&pmc->uckr);
29 	tmp |= AT91_PMC_UPLLEN |
30 	       AT91_PMC_UPLLCOUNT |
31 	       AT91_PMC_BIASEN;
32 	writel(tmp, &pmc->uckr);
33 
34 	while (!(readl(&pmc->sr) & AT91_PMC_LOCKU))
35 		;
36 
37 	return 0;
38 }
39 
40 static ulong utmi_clk_get_rate(struct clk *clk)
41 {
42 	return gd->arch.main_clk_rate_hz * UTMI_FIXED_MUL;
43 }
44 
45 static struct clk_ops utmi_clk_ops = {
46 	.enable = utmi_clk_enable,
47 	.get_rate = utmi_clk_get_rate,
48 };
49 
50 static int utmi_clk_probe(struct udevice *dev)
51 {
52 	return at91_pmc_core_probe(dev);
53 }
54 
55 static const struct udevice_id utmi_clk_match[] = {
56 	{ .compatible = "atmel,at91sam9x5-clk-utmi" },
57 	{}
58 };
59 
60 U_BOOT_DRIVER(at91sam9x5_utmi_clk) = {
61 	.name = "at91sam9x5-utmi-clk",
62 	.id = UCLASS_CLK,
63 	.of_match = utmi_clk_match,
64 	.probe = utmi_clk_probe,
65 	.platdata_auto_alloc_size = sizeof(struct pmc_platdata),
66 	.ops = &utmi_clk_ops,
67 };
68