diff options
| -rw-r--r-- | drivers/char/Kconfig | 9 | ||||
| -rw-r--r-- | drivers/tty/hvc/Makefile | 1 | ||||
| -rw-r--r-- | drivers/tty/hvc/hvc_bfin_jtag.c | 105 |
3 files changed, 115 insertions, 0 deletions
diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig index b7980a83ce2d..17f9b968b988 100644 --- a/drivers/char/Kconfig +++ b/drivers/char/Kconfig @@ -691,6 +691,15 @@ config HVC_DCC driver. This console is used through a JTAG only on ARM. If you don't have a JTAG then you probably don't want this option. +config HVC_BFIN_JTAG + bool "Blackfin JTAG console" + depends on BLACKFIN + select HVC_DRIVER + help + This console uses the Blackfin JTAG to create a console under the + the HVC driver. If you don't have JTAG, then you probably don't + want this option. + config VIRTIO_CONSOLE tristate "Virtio console" depends on VIRTIO diff --git a/drivers/tty/hvc/Makefile b/drivers/tty/hvc/Makefile index e6bed5f177ff..7b0edbce9009 100644 --- a/drivers/tty/hvc/Makefile +++ b/drivers/tty/hvc/Makefile @@ -9,5 +9,6 @@ obj-$(CONFIG_HVC_IRQ) += hvc_irq.o obj-$(CONFIG_HVC_XEN) += hvc_xen.o obj-$(CONFIG_HVC_IUCV) += hvc_iucv.o obj-$(CONFIG_HVC_UDBG) += hvc_udbg.o +obj-$(CONFIG_HVC_BFIN_JTAG) += hvc_bfin_jtag.o obj-$(CONFIG_HVCS) += hvcs.o obj-$(CONFIG_VIRTIO_CONSOLE) += virtio_console.o diff --git a/drivers/tty/hvc/hvc_bfin_jtag.c b/drivers/tty/hvc/hvc_bfin_jtag.c new file mode 100644 index 000000000000..31d6cc6a77af --- /dev/null +++ b/drivers/tty/hvc/hvc_bfin_jtag.c @@ -0,0 +1,105 @@ +/* + * Console via Blackfin JTAG Communication + * + * Copyright 2008-2011 Analog Devices Inc. + * + * Enter bugs at http://blackfin.uclinux.org/ + * + * Licensed under the GPL-2 or later. + */ + +#include <linux/console.h> +#include <linux/delay.h> +#include <linux/err.h> +#include <linux/init.h> +#include <linux/moduleparam.h> +#include <linux/types.h> + +#include "hvc_console.h" + +/* See the Debug/Emulation chapter in the HRM */ +#define EMUDOF 0x00000001 /* EMUDAT_OUT full & valid */ +#define EMUDIF 0x00000002 /* EMUDAT_IN full & valid */ +#define EMUDOOVF 0x00000004 /* EMUDAT_OUT overflow */ +#define EMUDIOVF 0x00000008 /* EMUDAT_IN overflow */ + +/* Helper functions to glue the register API to simple C operations */ +static inline uint32_t bfin_write_emudat(uint32_t emudat) +{ + __asm__ __volatile__("emudat = %0;" : : "d"(emudat)); + return emudat; +} + +static inline uint32_t bfin_read_emudat(void) +{ + uint32_t emudat; + __asm__ __volatile__("%0 = emudat;" : "=d"(emudat)); + return emudat; +} + +/* Send data to the host */ +static int hvc_bfin_put_chars(uint32_t vt, const char *buf, int count) +{ + static uint32_t outbound_len; + uint32_t emudat; + int ret; + + if (bfin_read_DBGSTAT() & EMUDOF) + return 0; + + if (!outbound_len) { + outbound_len = count; + bfin_write_emudat(outbound_len); + return 0; + } + + ret = min(outbound_len, (uint32_t)4); + memcpy(&emudat, buf, ret); + bfin_write_emudat(emudat); + outbound_len -= ret; + + return ret; +} + +/* Receive data from the host */ +static int hvc_bfin_get_chars(uint32_t vt, char *buf, int count) +{ + static uint32_t inbound_len; + uint32_t emudat; + int ret; + + if (!(bfin_read_DBGSTAT() & EMUDIF)) + return 0; + emudat = bfin_read_emudat(); + + if (!inbound_len) { + inbound_len = emudat; + return 0; + } + + ret = min(inbound_len, (uint32_t)4); + memcpy(buf, &emudat, ret); + inbound_len -= ret; + + return ret; +} + +/* Glue the HVC layers to the Blackfin layers */ +static const struct hv_ops hvc_bfin_get_put_ops = { + .get_chars = hvc_bfin_get_chars, + .put_chars = hvc_bfin_put_chars, +}; + +static int __init hvc_bfin_console_init(void) +{ + hvc_instantiate(0, 0, &hvc_bfin_get_put_ops); + return 0; +} +console_initcall(hvc_bfin_console_init); + +static int __init hvc_bfin_init(void) +{ + hvc_alloc(0, 0, &hvc_bfin_get_put_ops, 128); + return 0; +} +device_initcall(hvc_bfin_init); |