acpi.c

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/* SPDX-License-Identifier: GPL-2.0-or-later */
 
#include <acpi/acpigen.h>
#include <string.h>
#include "i915.h"
 
void
drivers_intel_gma_displays_ssdt_generate(const struct i915_gpu_controller_info *conf)
{
        size_t i;
        const char *names[] = { "UNK", "VGA", "TV", "DVI", "LCD" };
        int counters[ARRAY_SIZE(names)] = { 0 };
 
        if (!conf->ndid)
                return;
 
        acpigen_write_scope("\\_SB.PCI0.GFX0");
 
        /*
          Method (_DOD, 0)
          {
                Return (Package() {
                                0x5a5a5a5a,
                                0x5a5a5a5a,
                                0x5a5a5a5a
                        })
          }
        */
        acpigen_write_method("_DOD", 0);
 
        acpigen_emit_byte(RETURN_OP);
        acpigen_write_package(conf->ndid);
        for (i = 0; i < conf->ndid; i++) {
                acpigen_write_dword (conf->did[i] | 0x80010000);
        }
        acpigen_pop_len(); /* End Package. */
 
        acpigen_pop_len(); /* End Method. */
 
        for (i = 0; i < conf->ndid; i++) {
                char name[5];
                int kind;
 
                kind = (conf->did[i] >> 8) & 0xf;
                if (kind >= ARRAY_SIZE(names)) {
                        kind = 0;
                }
 
                snprintf(name, sizeof(name), "%s%d", names[kind], counters[kind]);
                counters[kind]++;
 
                /* Device (LCD0) */
                acpigen_write_device(name);
 
                /* Name (_ADR, 0x0410) */
                acpigen_write_name_dword("_ADR", conf->did[i] & 0xffff);
 
                /* ACPI brightness for LCD.  */
                if (kind == 4) {
                        /*
                          Method (_BCL, 0, NotSerialized)
                          {
                                Return (^^XBCL())
                          }
                        */
                        acpigen_write_method("_BCL", 0);
                        acpigen_emit_byte(RETURN_OP);
                        acpigen_emit_namestring("^^XBCL");
                        acpigen_pop_len();
 
                        /*
                          Method (_BCM, 1, NotSerialized)
                          {
                                ^^XBCM(Arg0)
                          }
                        */
                        acpigen_write_method("_BCM", 1);
                        acpigen_emit_namestring("^^XBCM");
                        acpigen_emit_byte(ARG0_OP);
                        acpigen_pop_len();
 
                        /*
                          Method (_BQC, 0, NotSerialized)
                          {
                                Return (^^XBQC())
                          }
                        */
                        acpigen_write_method("_BQC", 0);
                        acpigen_emit_byte(RETURN_OP);
                        acpigen_emit_namestring("^^XBQC");
                        acpigen_pop_len();
                }
 
                /*
                 * _DCS, _DGS and _DSS are required by specification. However,
                 * we never implemented them properly, and no OS driver com-
                 * plained yet. So we stub them out and keep the traditional
                 * behavior in case an OS driver checks for their existence.
                 */
 
                /*
                  Method(_DCS, 0)
                  {
                        Return (0x1d)
                  }
                */
                acpigen_write_method("_DCS", 0);
                acpigen_write_return_integer(0x1d);
                acpigen_pop_len();
 
                /*
                  Method(_DGS, 0)
                  {
                        Return (0)
                  }
                */
                acpigen_write_method("_DGS", 0);
                acpigen_write_return_integer(0);
                acpigen_pop_len();
 
                /*
                  Method(_DSS, 1)
                  {
                  }
                */
                acpigen_write_method("_DSS", 1);
                acpigen_pop_len();
 
                acpigen_pop_len(); /* End Device. */
        }
 
        acpigen_pop_len(); /* End Scope. */
}