ramstage.c

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/* SPDX-License-Identifier: GPL-2.0-or-later */
 
#include <bootstate.h>
#include <arch/mmio.h>
#include <delay.h>
#include <bootmode.h>
#include <device/device.h>
#include <device/pci.h>
#include <soc/pci_devs.h>
#include <drivers/intel/gma/i915_reg.h>
 
static void panel_power_on(uintptr_t igd_bar)
{
        setbits32((void *)(igd_bar + PCH_PP_CONTROL), PANEL_POWER_ON);
}
 
static void panel_reset_assert(uintptr_t igd_bar)
{
        clrsetbits32((void *)(igd_bar + PCH_GPIOB),
                GPIO_CLOCK_VAL_OUT,
                GPIO_CLOCK_DIR_MASK | GPIO_CLOCK_DIR_OUT | GPIO_CLOCK_VAL_MASK);
}
 
static void panel_reset_deassert(uintptr_t igd_bar)
{
        const uint32_t data32 = GPIO_CLOCK_VAL_OUT |
                GPIO_CLOCK_DIR_MASK | GPIO_CLOCK_DIR_OUT | GPIO_CLOCK_VAL_MASK;
        setbits32((void *)(igd_bar + PCH_GPIOB), data32);
}
 
/*
 * Bugzzy uses panel-built-in touch screen, it needs to set panel power and
 * reset signal to high for touch screen to work.
 * On user mode, coreboot doesn't initialize graphics since there is no screen
 * display before OS. We would add this WA to initialize required signals on
 * user mode.
 */
static void wa_init_display_signal(void *unused)
{
        struct device *igd_dev = pcidev_path_on_root(SA_DEVFN_IGD);
        uintptr_t igd_bar;
 
        if (display_init_required() || !igd_dev)
                return;
 
        igd_bar = find_resource(igd_dev, PCI_BASE_ADDRESS_0)->base;
        if (!igd_bar)
                return;
 
        panel_power_on(igd_bar);
        mdelay(20);
        panel_reset_deassert(igd_bar);
        mdelay(2);
        panel_reset_assert(igd_bar);
        mdelay(2);
        panel_reset_deassert(igd_bar);
}
 
BOOT_STATE_INIT_ENTRY(BS_POST_DEVICE, BS_ON_ENTRY, wa_init_display_signal, NULL);