GNUBoot
/
coreboot-kgpe-d16
2
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

arch/x86/acpigen: Add support for interacting with GPIOs 

Since reading/toggling of GPIOs is platform-dependent task, provide an
interface with common functions to generate ACPI AML code for
manipulating GPIOs:
1. acpigen_soc_read_rx_gpio
2. acpigen_soc_get_tx_gpio
3. acpigen_soc_set_tx_gpio
4. acpigen_soc_clear_tx_gpio

Provide weak implementations of above functions. These functions are
expected to be implemented by every SoC that uses ACPI. This allows
drivers to easily generate ACPI AML code to interact GPIOs.

BUG=chrome-os-partner:55988

Change-Id: I3564f15a1cb50e6ca6132638447529648589aa0e
Signed-off-by: Furquan Shaikh <furquan@chromium.org>
Reviewed-on: https://review.coreboot.org/17080
Tested-by: build bot (Jenkins)
Reviewed-by: Duncan Laurie <dlaurie@chromium.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
This commit is contained in:
Furquan Shaikh 2016-10-20 07:12:49 -07:00 committed by Furquan Shaikh
parent fcc7a04cc8
commit 0a48aee795
2 changed files with 51 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

29
src/arch/x86/acpigen.c
View File

@ -992,3 +992,32 @@ void acpigen_write_else(void)
acpigen_emit_byte(ELSE_OP); acpigen_emit_byte(ELSE_OP);
acpigen_write_len_f(); acpigen_write_len_f();
} }
/* Soc-implemented functions -- weak definitions. */
int __attribute__((weak)) acpigen_soc_read_rx_gpio(unsigned int gpio_num)
{
printk(BIOS_ERR, "ERROR: %s not implemented\n", __func__);
acpigen_write_debug_string("read_rx_gpio not available");
return -1;
}
int __attribute__((weak)) acpigen_soc_get_tx_gpio(unsigned int gpio_num)
{
printk(BIOS_ERR, "ERROR: %s not implemented\n", __func__);
acpigen_write_debug_string("get_tx_gpio not available");
return -1;
}
int __attribute__((weak)) acpigen_soc_set_tx_gpio(unsigned int gpio_num)
{
printk(BIOS_ERR, "ERROR: %s not implemented\n", __func__);
acpigen_write_debug_string("set_tx_gpio not available");
return -1;
}
int __attribute__((weak)) acpigen_soc_clear_tx_gpio(unsigned int gpio_num)
{
printk(BIOS_ERR, "ERROR: %s not implemented\n", __func__);
acpigen_write_debug_string("clear_tx_gpio not available");
return -1;
}

22
src/arch/x86/include/arch/acpigen.h
View File

@ -160,4 +160,26 @@ void acpigen_write_else(void);
int get_cst_entries(acpi_cstate_t **); int get_cst_entries(acpi_cstate_t **);
/*
* Soc-implemented functions for generating ACPI AML code for GPIO handling. All
* these functions are expected to use only Local5, Local6 and Local7
* variables. If the functions call into another ACPI method, then there is no
* restriction on the use of Local variables. In case of get/read functions,
* return value is expected to be stored in Local0 variable.
*
* All functions return 0 on success and -1 on error.
*/
/* Generate ACPI AML code to return Rx value of GPIO in Local0. */
int acpigen_soc_read_rx_gpio(unsigned int gpio_num);
/* Generate ACPI AML code to return Tx value of GPIO in Local0. */
int acpigen_soc_get_tx_gpio(unsigned int gpio_num);
/* Generate ACPI AML code to set Tx value of GPIO to 1. */
int acpigen_soc_set_tx_gpio(unsigned int gpio_num);
/* Generate ACPI AML code to set Tx value of GPIO to 0. */
int acpigen_soc_clear_tx_gpio(unsigned int gpio_num);
#endif #endif