1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * MPC5200 PSC serial console support. |
4 | * |
5 | * Author: Grant Likely <grant.likely@secretlab.ca> |
6 | * |
7 | * Copyright (c) 2007 Secret Lab Technologies Ltd. |
8 | * Copyright (c) 2007 Freescale Semiconductor, Inc. |
9 | * |
10 | * It is assumed that the firmware (or the platform file) has already set |
11 | * up the port. |
12 | */ |
13 | |
14 | #include "types.h" |
15 | #include "io.h" |
16 | #include "ops.h" |
17 | |
18 | /* Programmable Serial Controller (PSC) status register bits */ |
19 | #define MPC52xx_PSC_SR 0x04 |
20 | #define MPC52xx_PSC_SR_RXRDY 0x0100 |
21 | #define MPC52xx_PSC_SR_RXFULL 0x0200 |
22 | #define MPC52xx_PSC_SR_TXRDY 0x0400 |
23 | #define MPC52xx_PSC_SR_TXEMP 0x0800 |
24 | |
25 | #define MPC52xx_PSC_BUFFER 0x0C |
26 | |
27 | static void *psc; |
28 | |
29 | static int psc_open(void) |
30 | { |
31 | /* Assume the firmware has already configured the PSC into |
32 | * uart mode */ |
33 | return 0; |
34 | } |
35 | |
36 | static void psc_putc(unsigned char c) |
37 | { |
38 | while (!(in_be16(addr: psc + MPC52xx_PSC_SR) & MPC52xx_PSC_SR_TXRDY)) ; |
39 | out_8(addr: psc + MPC52xx_PSC_BUFFER, val: c); |
40 | } |
41 | |
42 | static unsigned char psc_tstc(void) |
43 | { |
44 | return (in_be16(addr: psc + MPC52xx_PSC_SR) & MPC52xx_PSC_SR_RXRDY) != 0; |
45 | } |
46 | |
47 | static unsigned char psc_getc(void) |
48 | { |
49 | while (!(in_be16(addr: psc + MPC52xx_PSC_SR) & MPC52xx_PSC_SR_RXRDY)) ; |
50 | return in_8(addr: psc + MPC52xx_PSC_BUFFER); |
51 | } |
52 | |
53 | int mpc5200_psc_console_init(void *devp, struct serial_console_data *scdp) |
54 | { |
55 | /* Get the base address of the psc registers */ |
56 | if (dt_get_virtual_reg(node: devp, addr: &psc, nres: 1) < 1) |
57 | return -1; |
58 | |
59 | scdp->open = psc_open; |
60 | scdp->putc = psc_putc; |
61 | scdp->getc = psc_getc; |
62 | scdp->tstc = psc_tstc; |
63 | |
64 | return 0; |
65 | } |
66 | |