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