tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * MPC5200 PSC serial console support.
3 *
4 * Author: Grant Likely <grant.likely@secretlab.ca>
5 *
6 * Copyright (c) 2007 Secret Lab Technologies Ltd.
7 * Copyright (c) 2007 Freescale Semiconductor, Inc.
8 *
9 * It is assumed that the firmware (or the platform file) has already set
10 * up the port.
11 */
12
13#include "types.h"
14#include "io.h"
15#include "ops.h"
16
17/* Programmable Serial Controller (PSC) status register bits */
18#define MPC52xx_PSC_SR 0x04
19#define MPC52xx_PSC_SR_RXRDY 0x0100
20#define MPC52xx_PSC_SR_RXFULL 0x0200
21#define MPC52xx_PSC_SR_TXRDY 0x0400
22#define MPC52xx_PSC_SR_TXEMP 0x0800
23
24#define MPC52xx_PSC_BUFFER 0x0C
25
26static void *psc;
27
28static int psc_open(void)
29{
30 /* Assume the firmware has already configured the PSC into
31 * uart mode */
32 return 0;
33}
34
35static void psc_putc(unsigned char c)
36{
37 while (!(in_be16(psc + MPC52xx_PSC_SR) & MPC52xx_PSC_SR_TXRDY)) ;
38 out_8(psc + MPC52xx_PSC_BUFFER, c);
39}
40
41static unsigned char psc_tstc(void)
42{
43 return (in_be16(psc + MPC52xx_PSC_SR) & MPC52xx_PSC_SR_RXRDY) != 0;
44}
45
46static unsigned char psc_getc(void)
47{
48 while (!(in_be16(psc + MPC52xx_PSC_SR) & MPC52xx_PSC_SR_RXRDY)) ;
49 return in_8(psc + MPC52xx_PSC_BUFFER);
50}
51
52int mpc5200_psc_console_init(void *devp, struct serial_console_data *scdp)
53{
54 int n;
55
56 /* Get the base address of the psc registers */
57 n = getprop(devp, "virtual-reg", &psc, sizeof(psc));
58 if (n != sizeof(psc)) {
59 if (!dt_xlate_reg(devp, 0, (void *)&psc, NULL))
60 return -1;
61 }
62
63 scdp->open = psc_open;
64 scdp->putc = psc_putc;
65 scdp->getc = psc_getc;
66 scdp->tstc = psc_tstc;
67
68 return 0;
69}