diff options
Diffstat (limited to 'kernel/drivers/ps2/ps2.c')
| -rw-r--r-- | kernel/drivers/ps2/ps2.c | 229 |
1 files changed, 229 insertions, 0 deletions
diff --git a/kernel/drivers/ps2/ps2.c b/kernel/drivers/ps2/ps2.c new file mode 100644 index 0000000..1c73855 --- /dev/null +++ b/kernel/drivers/ps2/ps2.c @@ -0,0 +1,229 @@ +// MIT License, Copyright (c) 2021 Marvin Borner + +#include <assert.h> +#include <cpu.h> +#include <def.h> +#include <print.h> +#include <ps2.h> + +#define PS2_TIMEOUT 100000 + +struct ps2_status ps2_read_status(void) +{ + u8 byte = inb(0x64); + return *(struct ps2_status *)&byte; +} + +static u8 ps2_wait_readable(void) +{ + u32 time_out = PS2_TIMEOUT; + while (time_out--) + if (ps2_read_status().in_full) + return 1; + /* print("PS/2 readable timeout\n"); */ + return 0; +} + +static u8 ps2_wait_writable(void) +{ + u32 time_out = PS2_TIMEOUT; + while (time_out--) + if (!ps2_read_status().out_full) + return 1; + /* print("PS/2 writable timeout\n"); */ + return 0; +} + +u8 ps2_read_data(void) +{ + if (ps2_wait_readable()) { + return inb(0x60); + } else { + return 0; + } +} + +u8 ps2_write_data(u8 byte) +{ + if (ps2_wait_writable()) { + outb(0x60, byte); + return 1; + } else { + return 0; + } +} + +u8 ps2_write_command(u8 byte) +{ + if (ps2_wait_writable()) { + outb(0x64, byte); + return 1; + } else { + return 0; + } +} + +CLEAR static struct ps2_config ps2_read_config(void) +{ + assert(ps2_write_command(0x20)); + u8 config = ps2_read_data(); + return *(struct ps2_config *)&config; +} + +CLEAR static u8 ps2_write_config(struct ps2_config config) +{ + // Select first byte + if (!ps2_write_command(0x60)) + return 0; + + return ps2_write_data(*(u8 *)&config); +} + +#define PS2_TYPE_STANDARD_MOUSE 0x0000 +#define PS2_TYPE_WHEEL_MOUSE 0x0003 +#define PS2_TYPE_BUTTON_MOUSE 0x0004 +#define PS2_TYPE_TRANSLATION_KEYBOARD1 0xab41 +#define PS2_TYPE_TRANSLATION_KEYBOARD2 0xabc1 +#define PS2_TYPE_STANDARD_KEYBOARD 0xab83 + +PROTECTED static struct { + u8 detected : 1; + struct { + u8 exists : 1; + u16 type; + } first; + struct { + u8 exists : 1; + u16 type; + } second; +} info = { 0 }; + +CLEAR static u8 ps2_write_device(u8 device, u8 data) +{ + u8 resp = PS2_RESEND; + for (u8 i = 0; resp == PS2_RESEND && i < 3; i++) { + if (device == 1) + ps2_write_command(0xd4); + ps2_write_data(data); + resp = ps2_read_data(); + } + + if (resp != PS2_ACK) + return 0; + + return 1; +} + +CLEAR static u8 ps2_device_keyboard(u16 type) +{ + return type == PS2_TYPE_TRANSLATION_KEYBOARD1 || type == PS2_TYPE_TRANSLATION_KEYBOARD2 || + type == PS2_TYPE_STANDARD_KEYBOARD; +} + +CLEAR static u8 ps2_device_mouse(u16 type) +{ + return type == PS2_TYPE_STANDARD_MOUSE || type == PS2_TYPE_WHEEL_MOUSE || + type == PS2_TYPE_BUTTON_MOUSE; +} + +CLEAR u8 ps2_keyboard_support(void) +{ + if (!info.detected) + return 0; + + // Find, reset and self-test + if ((info.first.exists && ps2_device_keyboard(info.first.type) && + ps2_write_device(0, 0xff)) || + (info.second.exists && ps2_device_keyboard(info.second.type) && + ps2_write_device(1, 0xff))) + return ps2_read_data() == 0xaa; + + return 0; +} + +CLEAR u8 ps2_mouse_support(void) +{ + if (!info.detected) + return 0; + + // Find, reset and self-test + if ((info.first.exists && ps2_device_mouse(info.first.type) && ps2_write_device(0, 0xff)) || + (info.second.exists && ps2_device_mouse(info.second.type) && ps2_write_device(1, 0xff))) + return ps2_read_data() == 0xaa; + + return 0; +} + +CLEAR void ps2_detect(void) +{ + // TODO: Read ACPI 8042 flag in FADT to verify PS/2 support + + // Disable PS/2 ports + ps2_write_command(0xad); + ps2_write_command(0xa7); + + // Get config and disable IRQs + struct ps2_config config = ps2_read_config(); + assert(!config.zero1 && !config.zero2); + config.first_int = 0; + config.second_int = 0; + ps2_write_config(config); + + // Test PS/2 controller + ps2_write_command(0xaa); + if (ps2_read_data() != 0x55) + return; + ps2_write_config(config); + + // Test first PS/2 port + ps2_write_command(0xab); + if (ps2_read_data() == 0x0) { + // Enable first port + ps2_write_command(0xae); + config.first_int = 1; + config.first_clock_disabled = 0; + info.first.exists = 1; + } + + // Test and enable second PS/2 port if available + if (config.second_clock_disabled) { + ps2_write_command(0xa9); + if (ps2_read_data() == 0x0) { + // Enable second port + ps2_write_command(0xa8); + config.second_int = 1; + config.second_clock_disabled = 0; + info.second.exists = 1; + } + } + + ps2_write_config(config); + + // Detect device type of first port + if (info.first.exists) { + if (!ps2_write_device(0, 0xf5)) + return; + + if (!ps2_write_device(0, 0xf2)) + return; + + u8 first = ps2_read_data(); + u8 second = ps2_read_data(); + info.first.type = (first << 8) | second; + } + + // Detect device type of second port + if (info.second.exists) { + if (!ps2_write_device(1, 0xf5)) + return; + + if (!ps2_write_device(1, 0xf2)) + return; + + u8 first = ps2_read_data(); + u8 second = ps2_read_data(); // This shall timeout if it's a mouse + info.second.type = (first << 8) | second; + } + + info.detected = 1; +} |