1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2
3 /*
4 * A generic romstage (pre-ram) driver for Nuvoton variant Super I/O chips.
5 *
6 * The following is derived directly from the vendor Nuvoton's data-sheets:
7 *
8 * To toggle between `configuration mode` and `normal operation mode` as to
9 * manipulate the various LDN's in Nuvoton Super I/O's we are required to
10 * pass magic numbers `passwords keys`.
11 *
12 * NUVOTON_ENTRY_KEY := enable configuration : 0x87
13 * NUVOTON_EXIT_KEY := disable configuration : 0xAA
14 *
15 * To modify a LDN's configuration register, we use the index port to select
16 * the index of the LDN and then write to the data port to alter the
17 * parameters. A default index, data port pair is 0x4E, 0x4F respectively, a
18 * user modified pair is 0x2E, 0x2F respectively.
19 *
20 */
21
22 #include <arch/io.h>
23 #include <device/pnp_ops.h>
24 #include <device/pnp.h>
25 #include <stdint.h>
26 #include "nuvoton.h"
27
28 #define NUVOTON_ENTRY_KEY 0x87
29 #define NUVOTON_EXIT_KEY 0xAA
30
31 /* Enable configuration: pass entry key '0x87' into index port dev
32 * two times. */
nuvoton_pnp_enter_conf_state(pnp_devfn_t dev)33 void nuvoton_pnp_enter_conf_state(pnp_devfn_t dev)
34 {
35 u16 port = dev >> 8;
36 outb(NUVOTON_ENTRY_KEY, port);
37 outb(NUVOTON_ENTRY_KEY, port);
38 }
39
40 /* Disable configuration: pass exit key '0xAA' into index port dev. */
nuvoton_pnp_exit_conf_state(pnp_devfn_t dev)41 void nuvoton_pnp_exit_conf_state(pnp_devfn_t dev)
42 {
43 u16 port = dev >> 8;
44 outb(NUVOTON_EXIT_KEY, port);
45 }
46
47 /* Bring up early serial debugging output before the RAM is initialized. */
nuvoton_enable_serial(pnp_devfn_t dev,u16 iobase)48 void nuvoton_enable_serial(pnp_devfn_t dev, u16 iobase)
49 {
50 if (!CONFIG(CONSOLE_SERIAL))
51 return;
52
53 nuvoton_pnp_enter_conf_state(dev);
54
55 if (CONFIG(SUPERIO_NUVOTON_COMMON_COM_A))
56 /* Route COM A to GPIO8 pin group */
57 pnp_unset_and_set_config(dev, 0x2a, 1 << 7, 0);
58
59 pnp_set_logical_device(dev);
60 pnp_set_enable(dev, 0);
61 pnp_set_iobase(dev, PNP_IDX_IO0, iobase);
62 pnp_set_enable(dev, 1);
63 nuvoton_pnp_exit_conf_state(dev);
64 }
65