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acpi: Add support for writing UART device descriptors

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This change adds support for generating the device descriptor that
corresponds to the UARTSerialBusV2() ACPI macro.

The resulting ACPI code for ACPI_UART_RAW_DEVICE(115200, 64) is:

UartSerialBusV2 (0x0001C200, DataBitsEight, StopBitsOne,
                 0x00, LittleEndian, ParityTypeNone, FlowControlNone,
                 0x0040, 0x0040, "\\_SB.PCI0.UAR2",
                 0x00, ResourceConsumer, , Exclusive)

Change-Id: I671ce2a499d74717d8677528c46ab3fbc1d7faf5
Signed-off-by: Duncan Laurie <dlaurie@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41792
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
This commit is contained in:
Duncan Laurie
2020-05-27 12:29:51 -07:00
committed by Furquan Shaikh
parent 84fac41d35
commit dccef0da0c
2 changed files with 163 additions and 0 deletions
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74
src/acpi/device.c
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@ -523,6 +523,80 @@ void acpi_device_write_spi(const struct acpi_spi *spi)
acpi_device_fill_len(desc_length);
}
/* UART Serial Bus - UARTSerialBusV2() */
void acpi_device_write_uart(const struct acpi_uart *uart)
{
void *desc_length, *type_length;
uint16_t flags;
/* Byte 0: Descriptor Type */
acpigen_emit_byte(ACPI_DESCRIPTOR_SERIAL_BUS);
/* Byte 1+2: Length (filled in later) */
desc_length = acpi_device_write_zero_len();
/* Byte 3: Revision ID */
acpigen_emit_byte(ACPI_UART_SERIAL_BUS_REVISION_ID);
/* Byte 4: Resource Source Index is Reserved */
acpigen_emit_byte(0);
/* Byte 5: Serial Bus Type is UART */
acpigen_emit_byte(ACPI_SERIAL_BUS_TYPE_UART);
/*
* Byte 6: Flags
* [7:2]: 0 => Reserved
* [1]: 1 => ResourceConsumer
* [0]: 0 => ControllerInitiated
*/
acpigen_emit_byte(BIT(1));
/*
* Byte 7-8: Type Specific Flags
* [15:8]: 0 => Reserved
* [7]: 0 => Little Endian, 1 => Big Endian
* [6:4]: Data bits
* [3:2]: Stop bits
* [1:0]: Flow control
*/
flags = uart->flow_control & 3;
flags |= (uart->stop_bits & 3) << 2;
flags |= (uart->data_bits & 7) << 4;
flags |= (uart->endian & 1) << 7;
acpigen_emit_word(flags);
/* Byte 9: Type Specific Revision ID */
acpigen_emit_byte(ACPI_UART_TYPE_SPECIFIC_REVISION_ID);
/* Byte 10-11: Type Data Length */
type_length = acpi_device_write_zero_len();
/* Byte 12-15: Initial Baud Rate */
acpigen_emit_dword(uart->initial_baud_rate);
/* Byte 16-17: RX FIFO size */
acpigen_emit_word(uart->rx_fifo_bytes);
/* Byte 18-19: TX FIFO size */
acpigen_emit_word(uart->tx_fifo_bytes);
/* Byte 20: Parity */
acpigen_emit_byte(uart->parity);
/* Byte 21: Lines Enabled */
acpigen_emit_byte(uart->lines_in_use);
/* Fill in Type Data Length */
acpi_device_fill_len(type_length);
/* Byte 22+: ResourceSource */
acpigen_emit_string(uart->resource);
/* Fill in Descriptor Length */
acpi_device_fill_len(desc_length);
}
/* PowerResource() with Enable and/or Reset control */
void acpi_device_add_power_res(const struct acpi_power_res_params *params)
{