projects / linux-2.6-block.git / blame
| Commit | Line | Data |
|---|---|---|
| 5427bcf5 MF |
1 | /* |
| 2 | * Console via Blackfin JTAG Communication | |
| 3 | * | |
| 4 | * Copyright 2008-2011 Analog Devices Inc. | |
| 5 | * | |
| 6 | * Enter bugs at http://blackfin.uclinux.org/ | |
| 7 | * | |
| 8 | * Licensed under the GPL-2 or later. | |
| 9 | */ | |
| 10 | ||
| 11 | #include <linux/console.h> | |
| 12 | #include <linux/delay.h> | |
| 13 | #include <linux/err.h> | |
| 14 | #include <linux/init.h> | |
| 15 | #include <linux/moduleparam.h> | |
| 16 | #include <linux/types.h> | |
| 17 | ||
| 18 | #include "hvc_console.h" | |
| 19 | ||
| 20 | /* See the Debug/Emulation chapter in the HRM */ | |
| 21 | #define EMUDOF 0x00000001 /* EMUDAT_OUT full & valid */ | |
| 22 | #define EMUDIF 0x00000002 /* EMUDAT_IN full & valid */ | |
| 23 | #define EMUDOOVF 0x00000004 /* EMUDAT_OUT overflow */ | |
| 24 | #define EMUDIOVF 0x00000008 /* EMUDAT_IN overflow */ | |
| 25 | ||
| 26 | /* Helper functions to glue the register API to simple C operations */ | |
| 27 | static inline uint32_t bfin_write_emudat(uint32_t emudat) | |
| 28 | { | |
| 29 | __asm__ __volatile__("emudat = %0;" : : "d"(emudat)); | |
| 30 | return emudat; | |
| 31 | } | |
| 32 | ||
| 33 | static inline uint32_t bfin_read_emudat(void) | |
| 34 | { | |
| 35 | uint32_t emudat; | |
| 36 | __asm__ __volatile__("%0 = emudat;" : "=d"(emudat)); | |
| 37 | return emudat; | |
| 38 | } | |
| 39 | ||
| 40 | /* Send data to the host */ | |
| 41 | static int hvc_bfin_put_chars(uint32_t vt, const char *buf, int count) | |
| 42 | { | |
| 43 | static uint32_t outbound_len; | |
| 44 | uint32_t emudat; | |
| 45 | int ret; | |
| 46 | ||
| 47 | if (bfin_read_DBGSTAT() & EMUDOF) | |
| 48 | return 0; | |
| 49 | ||
| 50 | if (!outbound_len) { | |
| 51 | outbound_len = count; | |
| 52 | bfin_write_emudat(outbound_len); | |
| 53 | return 0; | |
| 54 | } | |
| 55 | ||
| 56 | ret = min(outbound_len, (uint32_t)4); | |
| 57 | memcpy(&emudat, buf, ret); | |
| 58 | bfin_write_emudat(emudat); | |
| 59 | outbound_len -= ret; | |
| 60 | ||
| 61 | return ret; | |
| 62 | } | |
| 63 | ||
| 64 | /* Receive data from the host */ | |
| 65 | static int hvc_bfin_get_chars(uint32_t vt, char *buf, int count) | |
| 66 | { | |
| 67 | static uint32_t inbound_len; | |
| 68 | uint32_t emudat; | |
| 69 | int ret; | |
| 70 | ||
| 71 | if (!(bfin_read_DBGSTAT() & EMUDIF)) | |
| 72 | return 0; | |
| 73 | emudat = bfin_read_emudat(); | |
| 74 | ||
| 75 | if (!inbound_len) { | |
| 76 | inbound_len = emudat; | |
| 77 | return 0; | |
| 78 | } | |
| 79 | ||
| 80 | ret = min(inbound_len, (uint32_t)4); | |
| 81 | memcpy(buf, &emudat, ret); | |
| 82 | inbound_len -= ret; | |
| 83 | ||
| 84 | return ret; | |
| 85 | } | |
| 86 | ||
| 87 | /* Glue the HVC layers to the Blackfin layers */ | |
| 88 | static const struct hv_ops hvc_bfin_get_put_ops = { | |
| 89 | .get_chars = hvc_bfin_get_chars, | |
| 90 | .put_chars = hvc_bfin_put_chars, | |
| 91 | }; | |
| 92 | ||
| 93 | static int __init hvc_bfin_console_init(void) | |
| 94 | { | |
| 95 | hvc_instantiate(0, 0, &hvc_bfin_get_put_ops); | |
| 96 | return 0; | |
| 97 | } | |
| 98 | console_initcall(hvc_bfin_console_init); | |
| 99 | ||
| 100 | static int __init hvc_bfin_init(void) | |
| 101 | { | |
| 102 | hvc_alloc(0, 0, &hvc_bfin_get_put_ops, 128); | |
| 103 | return 0; | |
| 104 | } | |
| 105 | device_initcall(hvc_bfin_init); |