diff options
Diffstat (limited to 'src/superio/winbond/common')
| -rw-r--r-- | src/superio/winbond/common/early_serial.c | 72 | ||||
| -rw-r--r-- | src/superio/winbond/common/winbond.h | 29 |
2 files changed, 101 insertions, 0 deletions
diff --git a/src/superio/winbond/common/early_serial.c b/src/superio/winbond/common/early_serial.c new file mode 100644 index 0000000000..747cc458d0 --- /dev/null +++ b/src/superio/winbond/common/early_serial.c @@ -0,0 +1,72 @@ +/* + * This file is part of the coreboot project. + * + * Copyright (C) 2014 Edward O'Callaghan <eocallaghan@alterapraxis.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + */ + +/* + * A generic romstage (pre-ram) driver for Winbond variant Super I/O chips. + * + * The following is derived directly from the vendor Winbond's data-sheets: + * + * To toggle between `configuration mode` and `normal operation mode` as to + * manipulation the various LDN's in Winbond Super I/O's we are required to + * pass magic numbers `passwords keys`. + * + * WINBOUND_ENTRY_KEY := enable configuration : 0x87 + * WINBOUND_EXIT_KEY := disable configuration : 0xAA + * + * To modify a LDN's configuration register, we use the index port to select + * the index of the LDN and then write to the data port to alter the + * parameters. A default index, data port pair is 0x4E, 0x4F respectively, a + * user modified pair is 0x2E, 0x2F respectively. + * + */ + +#include <arch/io.h> +#include <device/pnp.h> +#include <stdint.h> +#include "winbond.h" + +#define WINBOND_ENTRY_KEY 0x87 +#define WINBOND_EXIT_KEY 0xAA + +/* Enable configuration: pass entry key '0x87' into index port dev. */ +static void pnp_enter_conf_state(device_t dev) +{ + u16 port = dev >> 8; + outb(WINBOND_ENTRY_KEY, port); + outb(WINBOND_ENTRY_KEY, port); +} + +/* Disable configuration: pass exit key '0xAA' into index port dev. */ +static void pnp_exit_conf_state(device_t dev) +{ + u16 port = dev >> 8; + outb(WINBOND_EXIT_KEY, port); +} + +/* Bring up early serial debugging output before the RAM is initialized. */ +void winbond_enable_serial(device_t dev, u16 iobase) +{ + pnp_enter_conf_state(dev); + pnp_set_logical_device(dev); + pnp_set_enable(dev, 0); + pnp_set_iobase(dev, PNP_IDX_IO0, iobase); + pnp_set_enable(dev, 1); + pnp_exit_conf_state(dev); +} diff --git a/src/superio/winbond/common/winbond.h b/src/superio/winbond/common/winbond.h new file mode 100644 index 0000000000..20eefc8029 --- /dev/null +++ b/src/superio/winbond/common/winbond.h @@ -0,0 +1,29 @@ +/* + * This file is part of the coreboot project. + * + * Copyright (C) 2014 Edward O'Callaghan <eocallaghan@alterapraxis.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#ifndef SUPERIO_WINBOND_COMMON_ROMSTAGE_H +#define SUPERIO_WINBOND_COMMON_ROMSTAGE_H + +#include <arch/io.h> +#include <stdint.h> + +void winbond_enable_serial(device_t dev, u16 iobase); + +#endif /* SUPERIO_WINBOND_COMMON_ROMSTAGE_H */ |