diff options
Diffstat (limited to 'src/ps2.c')
| -rw-r--r-- | src/ps2.c | 216 |
1 files changed, 216 insertions, 0 deletions
diff --git a/src/ps2.c b/src/ps2.c new file mode 100644 index 0000000..6491aed --- /dev/null +++ b/src/ps2.c @@ -0,0 +1,216 @@ +#include <stdbool.h> +#include <nrvn.h> +#include <acpi.h> +#include <vga.h> + +#define data_port 0x60 +#define status_reg 0x64 +#define cmd_reg 0x64 + +#define config_rcmd 0x20 +#define config_wcmd 0x60 +#define ctrl_test_cmd 0xaa + +static inline void print_port_status(bool second_port, const char *msg) { + vga_puts("ps/2 port "); + vga_puts(second_port ? "2 " : "1 "); + vga_puts(msg); +} + +static inline void send_cmd(uint8_t cmd) { + while (inb(status_reg) & 0x2); + outb(cmd_reg, cmd); +} + +static inline bool read_data(uint8_t *data_out) { + size_t counter = 50; + while (!(inb(status_reg) & 0x1) && --counter > 0); + if (counter == 0) + return false; + *data_out = inb(data_port); + return true; +} + +static inline void send_data(uint8_t data, bool second_device) { + if (second_device) + send_cmd(0xd4); + while (inb(status_reg) & 0x2); + outb(data_port, data); +} + +// TODO: ps/2 mouse interface is weird. +static bool interface_test(bool second_device) { + uint8_t rply; + + // Test port + send_cmd(second_device ? 0xa9 : 0xab); + read_data(&rply); + switch (rply) { + case 0x00: + print_port_status(second_device, "port test PASS\n"); + break; + case 0x01: + print_port_status(second_device, "FAIL clock line stuck low\n"); + return false; + case 0x02: + print_port_status(second_device, "FAIL clock line stuck high\n"); + return false; + case 0x03: + print_port_status(second_device, "FAIL data line stuck low\n"); + return false; + case 0x04: + print_port_status(second_device, "FAIL data line stuck data\n"); + return false; + } + + // Re-enable interface + send_cmd(second_device ? 0xa8 : 0xae); + + // reset and self test device + send_data(0xff, second_device); + if (!read_data(&rply)) { + print_port_status(second_device, "self-test FAIL: no reply\n"); + return false; + } + + switch (rply) { + case 0xFA: + if (read_data(&rply), rply == 0xaa) { + print_port_status(second_device, "self-test PASS\n"); + } else { + print_port_status(second_device, "self-test FAIL"); + vga_putx(rply); + vga_putc('\n'); + return false; + } + (void) inb(data_port); // PS/2 mouses send their id, we need to flush + break; + case 0xFC: + print_port_status(second_device, "self-test FAIL: "); + vga_putx(rply); + vga_putc('\n'); + return false; + default: + print_port_status(second_device, "self-test unknown reply: "); + vga_putx(rply); + vga_putc('\n'); + return false; + } + + // Disable device + print_port_status(second_device, "disabling scanning.\n"); + send_data(0xf5, second_device); + if (!read_data(&rply)) { + print_port_status( second_device, "failed to disable: "); + return false; + } + + if (rply != 0xfa && rply != 0xaa) { + print_port_status( second_device, "failed to disable: "); + vga_putx(rply); + vga_putc('\n'); + return false; + } + + print_port_status(second_device, "scanning disabled.\n"); + + print_port_status(second_device, "detecting device type.\n"); + send_data(0xf2, second_device); + if (read_data(&rply), rply != 0xfa) { + print_port_status(second_device, "failed to identify: "); + vga_putx(rply); + vga_putc('\n'); + return false; + } + print_port_status(second_device, "id ack: "); + vga_putx((read_data(&rply), rply)); + vga_putc(' '); + if (read_data(&rply)) + vga_putx(rply); + vga_putc('\n'); + + // Enable device + send_data(0xf4, second_device); + if (read_data(&rply), rply != 0xfa) { + print_port_status(second_device, "failed to enable: "); + vga_putx(rply); + vga_putc('\n'); + return false; + } + + print_port_status(second_device, "scanning enabled.\n"); + + return true; +} + +bool ps2_init(struct fadt *fadt) { + if (fadt != NULL && !(fadt->boot_arch_flags & 0x2)) { + vga_puts("fadt boot arch bit 1 not set: "); + vga_putx(fadt->boot_arch_flags); + vga_putc(' '); + vga_putx(((char*)fadt)[109]); + vga_putc('\n'); + } + + uint8_t rply; + + // Disable ps/2 devices + vga_puts("disabling first device\n"); + send_cmd(0xad); + vga_puts("disabling second device\n"); + send_cmd(0xa7); + + // flush output buffer + (void) inb(data_port); + + // set controller config, clearing bits 0, 1, and 6 + send_cmd(config_rcmd); + uint8_t config = (read_data(&rply), rply) & ~0b01000011; + + // check if dual channel is already set + bool dual_channel = !(config & 0x5); + + send_cmd(config_wcmd); + send_data(config, false); + + // perform controller self test + send_cmd(ctrl_test_cmd); + if (read_data(&rply), rply != 0x55) { + vga_puts("ps/2 controller self test failed: "); + vga_putx(rply); + vga_putc('\n'); + return false; + } + + // re-set config in case the self tests reset the device + send_cmd(config_wcmd); + send_data(config, false); + + // determine if there are two ports + if (!dual_channel) { + // attempt to enable second channel + send_cmd(0xa8); + + // check if configuration show second port + // and disable it again if it shows. + send_cmd(0x20); + if ((dual_channel = !((read_data(&rply), rply) & 0x5))) + send_cmd(0xa7); + } + + // enable and reset devices + if (!interface_test(false)) + vga_puts("failed to test port 1 interface\n"); + + if (dual_channel && !interface_test(true)) + vga_puts("failed to test port 2 interface\n"); + + // re enabled bits 1 and 2 (interrupts) + send_cmd(0x20); + config = (read_data(&rply), rply) | 0x3; + + send_cmd(0x60); + send_data(config, false); + + return true; +} |