ssdt.c

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/* SPDX-License-Identifier: GPL-2.0-or-later */
 
#include <superio/common/ssdt.h>
 
#include <device/device.h>
#include <device/pnp.h>
#include <acpi/acpigen.h>
#include <acpi/acpi.h>
#include <console/console.h>
#include <types.h>
#include <string.h>
 
struct superio_dev {
        const char *acpi_hid;
        u16 io_base[4];
        u8 irq[2];
};
 
static const struct superio_dev superio_devs[] = {
        {ACPI_HID_FDC, {0x3f0, 0x3f2, 0x3f7}, {6, } },
        {ACPI_HID_KEYBOARD, {60, 64, }, {1, } },
        {ACPI_HID_MOUSE, {60, 64, }, {12, } },
        {ACPI_HID_COM, {0x3f8, 0x2f8, 0x3e8, 0x2e8}, {4, 3} },
        {ACPI_HID_LPT, {0x378, }, {7, } },
};
 
static const u8 io_idx[] = {PNP_IDX_IO0, PNP_IDX_IO1, PNP_IDX_IO2, PNP_IDX_IO3};
static const u8 irq_idx[] = {PNP_IDX_IRQ0, PNP_IDX_IRQ1};
 
static const struct superio_dev *superio_guess_function(const struct device *dev)
{
        for (size_t i = 0; i < ARRAY_SIZE(io_idx); i++) {
                struct resource *res = probe_resource(dev, io_idx[i]);
                if (!res || !res->base)
                        continue;
 
                for (size_t j = 0; j < ARRAY_SIZE(superio_devs); j++) {
                        for (size_t k = 0; k < 4; k++) {
                                if (!superio_devs[j].io_base[k])
                                        continue;
                                if (superio_devs[j].io_base[k] == res->base)
                                        return &superio_devs[j];
                        }
                }
        }
        for (size_t i = 0; i < ARRAY_SIZE(irq_idx); i++) {
                struct resource *res = probe_resource(dev, irq_idx[i]);
                if (!res || !res->size)
                        continue;
                for (size_t j = 0; j < ARRAY_SIZE(superio_devs); j++) {
                        for (size_t k = 0; k < 2; k++) {
                                if (!superio_devs[j].irq[k])
                                        continue;
                                if (superio_devs[j].irq[k] == res->base)
                                        return &superio_devs[j];
                        }
                }
        }
        return NULL;
}
 
/* Return true if there are resources to report */
static bool has_resources(const struct device *dev)
{
        for (size_t i = 0; i < ARRAY_SIZE(io_idx); i++) {
                struct resource *res = probe_resource(dev, io_idx[i]);
                if (!res || !res->base || !res->size)
                        continue;
                return 1;
        }
        for (size_t i = 0; i < ARRAY_SIZE(irq_idx); i++) {
                struct resource *res = probe_resource(dev, irq_idx[i]);
                if (!res || !res->size || res->base > 16)
                        continue;
                return 1;
        }
        return 0;
}
 
/* Add IO and IRQ resources for _CRS or _PRS */
static void ldn_gen_resources(const struct device *dev)
{
        uint16_t irq = 0;
        for (size_t i = 0; i < ARRAY_SIZE(io_idx); i++) {
                struct resource *res = probe_resource(dev, io_idx[i]);
                if (!res || !res->base)
                        continue;
                resource_t base = res->base;
                resource_t size = res->size;
                while (size > 0) {
                        resource_t sz = size > 255 ? 255 : size;
                        /* TODO: Needs test with regions >= 256 bytes */
                        acpigen_write_io16(base, base, 1, sz, 1);
                        size -= sz;
                        base += sz;
                }
        }
        for (size_t i = 0; i < ARRAY_SIZE(irq_idx); i++) {
                struct resource *res = probe_resource(dev, irq_idx[i]);
                if (!res || !res->size || res->base >= 16)
                        continue;
                irq |= 1 << res->base;
        }
        if (irq)
                acpigen_write_irq(irq);
 
}
 
/* Add resource base and size for additional SuperIO code */
static void ldn_gen_resources_use(const struct device *dev)
{
        char name[5];
        for (size_t i = 0; i < ARRAY_SIZE(io_idx); i++) {
                struct resource *res = probe_resource(dev, io_idx[i]);
                if (!res || !res->base || !res->size)
                        continue;
 
                snprintf(name, sizeof(name), "IO%zXB", i);
                name[4] = '\0';
                acpigen_write_name_integer(name, res->base);
 
                snprintf(name, sizeof(name), "IO%zXS", i);
                name[4] = '\0';
                acpigen_write_name_integer(name, res->size);
        }
}
 
const char *superio_common_ldn_acpi_name(const struct device *dev)
{
        u8 ldn = dev->path.pnp.device & 0xff;
        u8 vldn = (dev->path.pnp.device >> 8) & 0x7;
        static char name[5];
 
        snprintf(name, sizeof(name), "L%02X%01X", ldn, vldn);
 
        name[4] = '\0';
 
        return name;
}
 
static const char *name_from_hid(const char *hid)
{
        static const struct {
                const char *hid;
                const char *name;
        } lookup[] = {
                {ACPI_HID_FDC, "FDC" },
                {ACPI_HID_KEYBOARD, "PS2 Keyboard" },
                {ACPI_HID_MOUSE, "PS2 Mouse"},
                {ACPI_HID_COM, "COM port" },
                {ACPI_HID_LPT, "LPT" },
                {ACPI_HID_PNP, "Generic PNP device" },
        };
 
        for (size_t i = 0; hid && i < ARRAY_SIZE(lookup); i++) {
                if (strcmp(hid, lookup[i].hid) == 0)
                        return lookup[i].name;
        }
        return "Generic device";
}
 
void superio_common_fill_ssdt_generator(const struct device *dev)
{
        if (!dev || !dev->bus || !dev->bus->dev) {
                printk(BIOS_CRIT, "BUG: Invalid argument in %s!\n", __func__);
                return;
        }
 
        const char *scope = acpi_device_scope(dev);
        const char *name = acpi_device_name(dev);
        const u8 ldn = dev->path.pnp.device & 0xff;
        const u8 vldn = (dev->path.pnp.device >> 8) & 0x7;
        const char *hid;
 
        /* Validate devicetree settings */
        bool bug = false;
        if (dev->bus->dev->path.type != DEVICE_PATH_PNP) {
                bug = true;
                printk(BIOS_CRIT, "BUG: Parent of device %s is not a PNP device\n",
                        dev_path(dev));
        } else if (dev->bus->dev->path.pnp.port != dev->path.pnp.port) {
                bug = true;
                printk(BIOS_CRIT, "BUG: Parent of device %s has wrong I/O port\n",
                        dev_path(dev));
        }
        if (bug) {
                printk(BIOS_CRIT, "BUG: Check your devicetree!\n");
                return;
        }
 
        if (!scope || !name) {
                printk(BIOS_ERR, "%s: Missing ACPI path/scope\n", dev_path(dev));
                return;
        }
        if (vldn) {
                printk(BIOS_DEBUG, "%s: Ignoring virtual LDN\n", dev_path(dev));
                return;
        }
 
        printk(BIOS_DEBUG, "%s.%s: %s\n", scope, name, dev_path(dev));
 
        /* Scope */
        acpigen_write_scope(scope);
 
        /* Device */
        acpigen_write_device(name);
 
        acpi_device_write_uid(dev);
 
        acpigen_write_name_byte("LDN", ldn);
        acpigen_write_name_byte("VLDN", vldn);
 
        acpigen_write_method("_STA", 0);
        {
                acpigen_write_store();
                acpigen_emit_namestring("^^QLDN");
                acpigen_write_integer(ldn);
                acpigen_emit_byte(LOCAL0_OP);
 
                /* Multiply (Local0, 0xf, Local0) */
                acpigen_emit_byte(MULTIPLY_OP);
                acpigen_emit_byte(LOCAL0_OP);
                acpigen_write_integer(0xf);
                acpigen_emit_byte(LOCAL0_OP);
 
                acpigen_emit_byte(RETURN_OP);
                acpigen_emit_byte(LOCAL0_OP);
 
        }
        acpigen_pop_len(); /* Method */
 
        /*
         * The ACPI6.2 spec Chapter 6.1.5 requires to set a  _HID if no _ADR
         * is present. Tests on Windows 10 showed that this is also true for
         * disabled (_STA = 0) devices, otherwise it BSODs.
         */
 
        hid = acpi_device_hid(dev);
        if (!hid) {
                printk(BIOS_ERR, "%s: SuperIO driver doesn't provide a _HID\n", dev_path(dev));
                /* Try to guess it... */
                const struct superio_dev *sdev = superio_guess_function(dev);
                if (sdev && sdev->acpi_hid) {
                        hid = sdev->acpi_hid;
                        printk(BIOS_WARNING, "%s: Guessed _HID is '%s'\n", dev_path(dev), hid);
                } else {
                        hid = ACPI_HID_PNP;
                        printk(BIOS_ERR, "%s: Failed to guessed _HID\n", dev_path(dev));
                }
        }
 
        acpigen_write_name_string("_HID", hid);
        acpigen_write_name_string("_DDN", name_from_hid(hid));
 
        acpigen_write_method("_DIS", 0);
        {
                acpigen_emit_namestring("^^DLDN");
                acpigen_write_integer(ldn);
        }
        acpigen_pop_len(); /* Method */
 
        if (dev->enabled && has_resources(dev)) {
                /* Resources - _CRS */
                acpigen_write_name("_CRS");
                acpigen_write_resourcetemplate_header();
                ldn_gen_resources(dev);
                acpigen_write_resourcetemplate_footer();
 
                /* Resources - _PRS */
                acpigen_write_name("_PRS");
                acpigen_write_resourcetemplate_header();
                ldn_gen_resources(dev);
                acpigen_write_resourcetemplate_footer();
 
                /* Resources base and size for 3rd party ACPI code */
                ldn_gen_resources_use(dev);
        }
 
        acpigen_pop_len(); /* Device */
        acpigen_pop_len(); /* Scope */
}