1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Generic serial console support 4 * 5 * Author: Mark A. Greer <mgreer@mvista.com> 6 * 7 * Code in serial_edit_cmdline() copied from <file:arch/ppc/boot/simple/misc.c> 8 * and was written by Matt Porter <mporter@kernel.crashing.org>. 9 * 10 * 2001,2006 (c) MontaVista Software, Inc. 11 */ 12 #include <stdarg.h> 13 #include <stddef.h> 14 #include "types.h" 15 #include "string.h" 16 #include "stdio.h" 17 #include "io.h" 18 #include "ops.h" 19 20 static int serial_open(void) 21 { 22 struct serial_console_data *scdp = console_ops.data; 23 return scdp->open(); 24 } 25 26 static void serial_write(const char *buf, int len) 27 { 28 struct serial_console_data *scdp = console_ops.data; 29 30 while (*buf != '\0') 31 scdp->putc(*buf++); 32 } 33 34 static void serial_edit_cmdline(char *buf, int len, unsigned int timeout) 35 { 36 int timer = 0, count; 37 char ch, *cp; 38 struct serial_console_data *scdp = console_ops.data; 39 40 cp = buf; 41 count = strlen(buf); 42 cp = &buf[count]; 43 count++; 44 45 do { 46 if (scdp->tstc()) { 47 while (((ch = scdp->getc()) != '\n') && (ch != '\r')) { 48 /* Test for backspace/delete */ 49 if ((ch == '\b') || (ch == '\177')) { 50 if (cp != buf) { 51 cp--; 52 count--; 53 printf("\b \b"); 54 } 55 /* Test for ^x/^u (and wipe the line) */ 56 } else if ((ch == '\030') || (ch == '\025')) { 57 while (cp != buf) { 58 cp--; 59 count--; 60 printf("\b \b"); 61 } 62 } else if (count < len) { 63 *cp++ = ch; 64 count++; 65 scdp->putc(ch); 66 } 67 } 68 break; /* Exit 'timer' loop */ 69 } 70 udelay(1000); /* 1 msec */ 71 } while (timer++ < timeout); 72 *cp = 0; 73 } 74 75 static void serial_close(void) 76 { 77 struct serial_console_data *scdp = console_ops.data; 78 79 if (scdp->close) 80 scdp->close(); 81 } 82 83 static void *serial_get_stdout_devp(void) 84 { 85 void *devp; 86 char devtype[MAX_PROP_LEN]; 87 char path[MAX_PATH_LEN]; 88 89 devp = finddevice("/chosen"); 90 if (devp == NULL) 91 goto err_out; 92 93 if (getprop(devp, "linux,stdout-path", path, MAX_PATH_LEN) > 0 || 94 getprop(devp, "stdout-path", path, MAX_PATH_LEN) > 0) { 95 devp = finddevice(path); 96 if (devp == NULL) 97 goto err_out; 98 99 if ((getprop(devp, "device_type", devtype, sizeof(devtype)) > 0) 100 && !strcmp(devtype, "serial")) 101 return devp; 102 } 103 err_out: 104 return NULL; 105 } 106 107 static struct serial_console_data serial_cd; 108 109 /* Node's "compatible" property determines which serial driver to use */ 110 int serial_console_init(void) 111 { 112 void *devp; 113 int rc = -1; 114 115 devp = serial_get_stdout_devp(); 116 if (devp == NULL) 117 goto err_out; 118 119 if (dt_is_compatible(devp, "ns16550") || 120 dt_is_compatible(devp, "pnpPNP,501")) 121 rc = ns16550_console_init(devp, &serial_cd); 122 #ifdef CONFIG_CPM 123 else if (dt_is_compatible(devp, "fsl,cpm1-scc-uart") || 124 dt_is_compatible(devp, "fsl,cpm1-smc-uart") || 125 dt_is_compatible(devp, "fsl,cpm2-scc-uart") || 126 dt_is_compatible(devp, "fsl,cpm2-smc-uart")) 127 rc = cpm_console_init(devp, &serial_cd); 128 #endif 129 #ifdef CONFIG_PPC_MPC52xx 130 else if (dt_is_compatible(devp, "fsl,mpc5200-psc-uart")) 131 rc = mpc5200_psc_console_init(devp, &serial_cd); 132 #endif 133 #ifdef CONFIG_PPC_POWERNV 134 else if (dt_is_compatible(devp, "ibm,opal-console-raw")) 135 rc = opal_console_init(devp, &serial_cd); 136 #endif 137 138 /* Add other serial console driver calls here */ 139 140 if (!rc) { 141 console_ops.open = serial_open; 142 console_ops.write = serial_write; 143 console_ops.close = serial_close; 144 console_ops.data = &serial_cd; 145 146 if (serial_cd.getc) 147 console_ops.edit_cmdline = serial_edit_cmdline; 148 149 return 0; 150 } 151 err_out: 152 return -1; 153 } 154