xref: /openbmc/u-boot/drivers/clk/at91/clk-h32mx.c (revision ee943655)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2016 Atmel Corporation
4  *               Wenyou.Yang <wenyou.yang@atmel.com>
5  */
6 
7 #include <common.h>
8 #include <clk-uclass.h>
9 #include <dm.h>
10 #include <dm/util.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 H32MX_MAX_FREQ	90000000
18 
19 static ulong sama5d4_h32mx_clk_get_rate(struct clk *clk)
20 {
21 	struct pmc_platdata *plat = dev_get_platdata(clk->dev);
22 	struct at91_pmc *pmc = plat->reg_base;
23 	ulong rate = gd->arch.mck_rate_hz;
24 
25 	if (readl(&pmc->mckr) & AT91_PMC_MCKR_H32MXDIV)
26 		rate /= 2;
27 
28 	if (rate > H32MX_MAX_FREQ)
29 		dm_warn("H32MX clock is too fast\n");
30 
31 	return rate;
32 }
33 
34 static struct clk_ops sama5d4_h32mx_clk_ops = {
35 	.get_rate = sama5d4_h32mx_clk_get_rate,
36 };
37 
38 static int sama5d4_h32mx_clk_probe(struct udevice *dev)
39 {
40 	return at91_pmc_core_probe(dev);
41 }
42 
43 static const struct udevice_id sama5d4_h32mx_clk_match[] = {
44 	{ .compatible = "atmel,sama5d4-clk-h32mx" },
45 	{}
46 };
47 
48 U_BOOT_DRIVER(sama5d4_h32mx_clk) = {
49 	.name = "sama5d4-h32mx-clk",
50 	.id = UCLASS_CLK,
51 	.of_match = sama5d4_h32mx_clk_match,
52 	.probe = sama5d4_h32mx_clk_probe,
53 	.platdata_auto_alloc_size = sizeof(struct pmc_platdata),
54 	.ops = &sama5d4_h32mx_clk_ops,
55 };
56