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Improve PS/2 initialization.

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This commit is contained in:
Enrico Fraccaroli
2022-01-24 14:16:26 -05:00
parent f95c361283
commit 30637c3a51
1 changed files with 60 additions and 23 deletions
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mentos/src/drivers/ps2.c
+60 -23
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@@ -21,22 +21,44 @@
#define PS2_STATUS 0x64
#define PS2_COMMAND 0x64
#define PS2_CTRL_TEST_CONTROLLER 0xAA ///< Test PS/2 Controller. 0x55 passed, 0xFC failed.
#define PS2_CTRL_P1_ENABLE 0xAE ///< Enable first PS/2 port. No response.
#define PS2_CTRL_P1_DISABLE 0xAD ///< Disable first PS/2 port. No response.
#define PS2_CTRL_P1_TEST 0xAB ///< Test first PS/2 port.
#define PS2_CTRL_P2_ENABLE 0xA8 ///< Enable second PS/2 port. No response.
#define PS2_CTRL_P2_DISABLE 0xA7 ///< Disable second PS/2 port. No response.
#define PS2_CTRL_P2_TEST 0xA9 ///< Test second PS/2 port (only if 2 PS/2 ports supported).
#define PS2_TEST_SUCCESS 0xAA
#define PS2_ECHO_RES 0xEE
#define PS2_ACK 0xFA
#define PS2_TEST_FAIL1 0xFC
#define PS2_TEST_FAIL2 0xFD
#define PS2_RESEND 0xFE
// PS/2 Controller Configuration Byte
// Bit | Meaning
// 0 | First PS/2 port interrupt (1 = enabled, 0 = disabled)
// 1 | Second PS/2 port interrupt (1 = enabled, 0 = disabled, only if 2 PS/2 ports supported)
// 2 | System Flag (1 = system passed POST, 0 = your OS shouldn't be running)
// 3 | Should be zero
// 4 | First PS/2 port clock (1 = disabled, 0 = enabled)
// 5 | Second PS/2 port clock (1 = disabled, 0 = enabled, only if 2 PS/2 ports supported)
// 6 | First PS/2 port translation (1 = enabled, 0 = disabled)
// 7 | Must be zero
/// @brief Polling until we can receive bytes from the device.
static inline void __ps2_wait_read()
{
int _time_out = 100000;
while (((inportb(PS2_STATUS) & 0x01) == 0x00) && (_time_out--)) {
while (!bit_check(inportb(PS2_STATUS), 0))
pause();
}
}
/// @brief Polling until we can send bytes to the device.
static inline void __ps2_wait_write()
{
int _time_out = 100000;
while (((inportb(PS2_STATUS) & 0x02) != 0x00) && (_time_out--)) {
while (bit_check(inportb(PS2_STATUS), 1))
pause();
}
}
void ps2_write(unsigned char data)
@@ -76,22 +98,22 @@ static inline int __ps2_is_dual_channel()
static inline void __ps2_enable_first_port()
{
__ps2_write_command(0xAE);
__ps2_write_command(PS2_CTRL_P1_ENABLE);
}
static inline void __ps2_enable_second_port()
{
__ps2_write_command(0xA8);
__ps2_write_command(PS2_CTRL_P2_ENABLE);
}
static inline void __ps2_disable_first_port()
{
__ps2_write_command(0xAD);
__ps2_write_command(PS2_CTRL_P1_DISABLE);
}
static inline void __ps2_disable_second_port()
{
__ps2_write_command(0xA7);
__ps2_write_command(PS2_CTRL_P2_DISABLE);
}
static inline void __ps2_write_first_port(unsigned char byte)
@@ -105,6 +127,19 @@ static inline void __ps2_write_second_port(unsigned char byte)
ps2_write(byte);
}
static const char *__ps2_get_response_error_message(unsigned response)
{
if (response == 0x01)
return "clock line stuck low";
if (response == 0x02)
return "clock line stuck high";
if (response == 0x03)
return "data line stuck low";
if (response == 0x04)
return "data line stuck high";
return "unknown error";
}
int ps2_initialize()
{
unsigned char status, response;
@@ -171,10 +206,10 @@ int ps2_initialize()
// based on the above table or restore the value read before issuing 0xAA.
// Send 0xAA to the controller.
__ps2_write_command(0xAA);
__ps2_write_command(PS2_CTRL_TEST_CONTROLLER);
// Read the response.
if ((response = ps2_read()) != 0x55) {
pr_err("Self-test failed : %d\n", response);
if ((response = ps2_read()) == PS2_TEST_FAIL1) {
pr_err("Self-test failed : 0x%02x\n", response);
return 1;
}
// Restore the value read before issuing 0xAA.
@@ -211,16 +246,18 @@ int ps2_initialize()
// Note: If one of the PS/2 ports on a dual PS/2 controller fails, then you
// can still keep using/supporting the other PS/2 port.
__ps2_write_command(0xAB);
if ((response = ps2_read())) {
pr_err("Interface test failed on first port : %d\n", response);
__ps2_write_command(PS2_CTRL_P1_TEST);
if ((response = ps2_read()) && (response >= 0x01) && (response <= 0x04)) {
pr_err("Interface test failed on first port : %02x\n", response);
pr_err("Reason: %s.\n", __ps2_get_response_error_message(response));
return 1;
}
// If it is a dual channel, check the second port.
if (dual) {
__ps2_write_command(0xA9);
if ((response = ps2_read())) {
pr_err("Interface test failed on second port : %d\n", response);
__ps2_write_command(PS2_CTRL_P2_TEST);
if ((response = ps2_read()) && (response >= 0x01) && (response <= 0x04)) {
pr_err("Interface test failed on second port : %02x\n", response);
pr_err("Reason: %s.\n", __ps2_get_response_error_message(response));
return 1;
}
}
@@ -263,12 +300,12 @@ int ps2_initialize()
// Reset first port.
__ps2_write_first_port(0xFF);
// Wait for `command acknowledged`.
if ((response = ps2_read()) != 0xFA) {
if ((response = ps2_read()) != PS2_ACK) {
pr_err("Failed to reset first PS/2 port: %d\n", response);
return 1;
}
// Wait for `self test successful`.
if ((response = ps2_read()) != 0xAA) {
if ((response = ps2_read()) != PS2_TEST_SUCCESS) {
pr_err("Failed to reset first PS/2 port: %d\n", response);
return 1;
}
@@ -276,12 +313,12 @@ int ps2_initialize()
// Reset second port.
__ps2_write_second_port(0xFF);
// Wait for `command acknowledged`.
if ((response = ps2_read()) != 0xFA) {
if ((response = ps2_read()) != PS2_ACK) {
pr_err("Failed to reset first PS/2 port: %d\n", response);
return 1;
}
// Wait for `self test successful`.
if ((response = ps2_read()) != 0xAA) {
if ((response = ps2_read()) != PS2_TEST_SUCCESS) {
pr_err("Failed to reset first PS/2 port: %d\n", response);
return 1;
}