xref: /openbmc/u-boot/drivers/clk/at91/clk-h32mx.c (revision b24a8ec1)
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 <dm/util.h>
12 #include <linux/io.h>
13 #include <mach/at91_pmc.h>
14 #include "pmc.h"
15 
16 DECLARE_GLOBAL_DATA_PTR;
17 
18 #define H32MX_MAX_FREQ	90000000
19 
20 static ulong sama5d4_h32mx_clk_get_rate(struct clk *clk)
21 {
22 	struct pmc_platdata *plat = dev_get_platdata(clk->dev);
23 	struct at91_pmc *pmc = plat->reg_base;
24 	ulong rate = gd->arch.mck_rate_hz;
25 
26 	if (readl(&pmc->mckr) & AT91_PMC_MCKR_H32MXDIV)
27 		rate /= 2;
28 
29 	if (rate > H32MX_MAX_FREQ)
30 		dm_warn("H32MX clock is too fast\n");
31 
32 	return rate;
33 }
34 
35 static struct clk_ops sama5d4_h32mx_clk_ops = {
36 	.get_rate = sama5d4_h32mx_clk_get_rate,
37 };
38 
39 static int sama5d4_h32mx_clk_probe(struct udevice *dev)
40 {
41 	return at91_pmc_core_probe(dev);
42 }
43 
44 static const struct udevice_id sama5d4_h32mx_clk_match[] = {
45 	{ .compatible = "atmel,sama5d4-clk-h32mx" },
46 	{}
47 };
48 
49 U_BOOT_DRIVER(sama5d4_h32mx_clk) = {
50 	.name = "sama5d4-h32mx-clk",
51 	.id = UCLASS_CLK,
52 	.of_match = sama5d4_h32mx_clk_match,
53 	.probe = sama5d4_h32mx_clk_probe,
54 	.platdata_auto_alloc_size = sizeof(struct pmc_platdata),
55 	.ops = &sama5d4_h32mx_clk_ops,
56 };
57