mux.c

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/* SPDX-License-Identifier: GPL-2.0-only */
 
#include <acpi/acpi_device.h>
#include <acpi/acpigen.h>
#include <console/console.h>
#include <device/device.h>
#include <device/path.h>
#include <string.h>
 
#include "chip.h"
 
static const char *i2c_gpiomux_mux_acpi_name(const struct device *dev)
{
        static char name[ACPI_NAME_BUFFER_SIZE];
 
        snprintf(name, ACPI_NAME_BUFFER_SIZE, "MUX%01.1X", dev->path.generic.id);
        return name;
}
 
static void i2c_gpiomux_mux_fill_ssdt(const struct device *dev)
{
        const char *scope = acpi_device_scope(dev);
        const char *path = acpi_device_path(dev);
        struct drivers_i2c_gpiomux_mux_config *config = config_of(dev);
        struct acpi_dp *dsd = NULL;
        const char *compat_string = "i2c-mux-gpio";
        struct acpi_gpio_res_params param[MAX_NUM_MUX_GPIOS];
        int i;
 
        if (!scope || !path)
                return;
 
        /* Device */
        acpigen_write_scope(scope);
        acpigen_write_device(acpi_device_name(dev));
        acpigen_write_name_string("_HID", ACPI_DT_NAMESPACE_HID);
        acpigen_write_STA(acpi_device_status(dev));
 
        /* Resources */
        acpigen_write_name("_CRS");
        acpigen_write_resourcetemplate_header();
        for (i = 0; i < config->mux_gpio_count; i++) {
                acpi_device_write_gpio(&config->mux_gpio[i]);
                param[i].ref = path;
                param[i].index = i;
                param[i].pin = 0;
                param[i].active_low = config->mux_gpio[i].active_low;
        }
        acpigen_write_resourcetemplate_footer();
 
        /* DSD */
        dsd = acpi_dp_new_table("_DSD");
        acpi_dp_add_string(dsd, "compatible", compat_string);
        acpi_dp_add_gpio_array(dsd, "mux-gpios", param, config->mux_gpio_count);
        acpi_dp_write(dsd);
 
        acpigen_pop_len(); /* Device */
        acpigen_pop_len(); /* Scope */
 
        printk(BIOS_INFO, "%s: %s at %s\n", path, dev->chip_ops->name, dev_path(dev));
}
 
static struct device_operations i2c_gpiomux_mux_ops = {
        .read_resources         = noop_read_resources,
        .set_resources          = noop_set_resources,
        .scan_bus               = scan_static_bus,
        .acpi_name              = i2c_gpiomux_mux_acpi_name,
        .acpi_fill_ssdt         = i2c_gpiomux_mux_fill_ssdt,
};
 
static void i2c_gpiomux_mux_enable(struct device *dev)
{
        if (!dev)
                return;
 
        dev->ops = &i2c_gpiomux_mux_ops;
}
 
struct chip_operations drivers_i2c_gpiomux_mux_ops = {
        CHIP_NAME("I2C GPIO MUX Device")
        .enable_dev = i2c_gpiomux_mux_enable
};