diff options
| -rw-r--r-- | Documentation/acpi/gpio.md | 9 | ||||
| -rw-r--r-- | src/arch/x86/acpigen.c | 17 | ||||
| -rw-r--r-- | src/arch/x86/include/arch/acpigen.h | 10 |
3 files changed, 36 insertions, 0 deletions
diff --git a/Documentation/acpi/gpio.md b/Documentation/acpi/gpio.md index d42042f36f..abde3a0d3d 100644 --- a/Documentation/acpi/gpio.md +++ b/Documentation/acpi/gpio.md @@ -73,6 +73,15 @@ calling the platform specific acpigen_soc_{set,clear}_tx_gpio functions internally. Thus, all the ACPI AML calling conventions for the platform functions apply to these helper functions as well. +3. Get Rx GPIO + int acpigen_get_rx_gpio(struct acpi_gpio gpio) + +This function takes as input, an struct acpi_gpio type and outputs +AML code to read the *logical* value of a gpio (after taking its +polarity into consideration), into the Local0 variable. It calls +the platform specific acpigen_soc_read_rx_gpio() to actually read +the raw Rx gpio value. + ## Implementation Details ACPI library in coreboot will provide weak definitions for all the diff --git a/src/arch/x86/acpigen.c b/src/arch/x86/acpigen.c index 72605bb766..9162cdb371 100644 --- a/src/arch/x86/acpigen.c +++ b/src/arch/x86/acpigen.c @@ -1203,6 +1203,15 @@ void acpigen_write_or(uint8_t arg1, uint8_t arg2, uint8_t res) acpigen_emit_byte(res); } +/* Xor (arg1, arg2, res) */ +void acpigen_write_xor(uint8_t arg1, uint8_t arg2, uint8_t res) +{ + acpigen_emit_byte(XOR_OP); + acpigen_emit_byte(arg1); + acpigen_emit_byte(arg2); + acpigen_emit_byte(res); +} + /* And (arg1, arg2, res) */ void acpigen_write_and(uint8_t arg1, uint8_t arg2, uint8_t res) { @@ -1759,6 +1768,14 @@ int acpigen_disable_tx_gpio(struct acpi_gpio *gpio) return acpigen_soc_clear_tx_gpio(gpio->pins[0]); } +void acpigen_get_rx_gpio(struct acpi_gpio *gpio) +{ + acpigen_soc_read_rx_gpio(gpio->pins[0]); + + if (gpio->polarity == ACPI_GPIO_ACTIVE_LOW) + acpigen_write_xor(LOCAL0_OP, 1, LOCAL0_OP); +} + /* refer to ACPI 6.4.3.5.3 Word Address Space Descriptor section for details */ void acpigen_resource_word(u16 res_type, u16 gen_flags, u16 type_flags, u16 gran, u16 range_min, u16 range_max, u16 translation, u16 length) diff --git a/src/arch/x86/include/arch/acpigen.h b/src/arch/x86/include/arch/acpigen.h index 08075585ca..34c5197468 100644 --- a/src/arch/x86/include/arch/acpigen.h +++ b/src/arch/x86/include/arch/acpigen.h @@ -361,6 +361,7 @@ void acpigen_write_sleep(uint64_t sleep_ms); void acpigen_write_store(void); void acpigen_write_store_ops(uint8_t src, uint8_t dst); void acpigen_write_or(uint8_t arg1, uint8_t arg2, uint8_t res); +void acpigen_write_xor(uint8_t arg1, uint8_t arg2, uint8_t res); void acpigen_write_and(uint8_t arg1, uint8_t arg2, uint8_t res); void acpigen_write_not(uint8_t arg, uint8_t res); void acpigen_write_debug_string(const char *str); @@ -472,6 +473,14 @@ int acpigen_soc_clear_tx_gpio(unsigned int gpio_num); int acpigen_enable_tx_gpio(struct acpi_gpio *gpio); int acpigen_disable_tx_gpio(struct acpi_gpio *gpio); +/* + * Helper function for getting a RX GPIO value based on the GPIO polarity. + * The return value is stored in Local0 variable. + * This function ends up calling acpigen_soc_get_rx_gpio to make callbacks + * into SoC acpigen code + */ +void acpigen_get_rx_gpio(struct acpi_gpio *gpio); + /* refer to ACPI 6.4.3.5.3 Word Address Space Descriptor section for details */ void acpigen_resource_word(u16 res_type, u16 gen_flags, u16 type_flags, u16 gran, u16 range_min, u16 range_max, u16 translation, u16 length); @@ -481,4 +490,5 @@ void acpigen_resource_dword(u16 res_type, u16 gen_flags, u16 type_flags, /* refer to ACPI 6.4.3.5.1 QWord Address Space Descriptor section for details */ void acpigen_resource_qword(u16 res_type, u16 gen_flags, u16 type_flags, u64 gran, u64 range_min, u64 range_max, u64 translation, u64 length); + #endif |