1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * (C) Copyright 2019, Microchip Technology, Inc.
4 * Author: Eugen Hristev <eugen.hristev@microchip.com>
5 */
6
7 #include <common.h>
8 #include <dm.h>
9 #include <errno.h>
10 #include <log.h>
11 #include <misc.h>
12 #include <asm/io.h>
13 #include <linux/err.h>
14
15 struct microchip_flexcom_regs {
16 u32 cr;
17 };
18
19 struct microchip_flexcom_plat {
20 struct microchip_flexcom_regs *regs;
21 u32 flexcom_mode;
22 };
23
microchip_flexcom_of_to_plat(struct udevice * dev)24 static int microchip_flexcom_of_to_plat(struct udevice *dev)
25 {
26 struct microchip_flexcom_plat *plat = dev_get_plat(dev);
27 int ret;
28
29 plat->regs = map_physmem(dev_read_addr(dev),
30 sizeof(struct microchip_flexcom_regs),
31 MAP_NOCACHE);
32
33 ret = dev_read_u32(dev, "atmel,flexcom-mode", &plat->flexcom_mode);
34
35 if (IS_ERR_VALUE(ret)) {
36 debug("Missing atmel,flexcom-mode property\n");
37 return ret;
38 }
39
40 /*
41 * The mode must have only 2 bits. If any other bits are set,
42 * the value is not supported.
43 */
44 if (plat->flexcom_mode & 0xfffffffc) {
45 debug("Wrong atmel,flexcom-mode property\n");
46 return -EINVAL;
47 }
48
49 writel(plat->flexcom_mode, &plat->regs->cr);
50
51 return 0;
52 }
53
54 static const struct udevice_id microchip_flexcom_ids[] = {
55 { .compatible = "atmel,sama5d2-flexcom" },
56 { .compatible = "microchip,flexcom" },
57 {}
58 };
59
60 U_BOOT_DRIVER(microchip_flexcom) = {
61 .name = "microchip_flexcom",
62 .id = UCLASS_MISC,
63 .of_match = microchip_flexcom_ids,
64 .of_to_plat = microchip_flexcom_of_to_plat,
65 .plat_auto = sizeof(struct microchip_flexcom_plat),
66 };
67