chromeos.c

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/* SPDX-License-Identifier: GPL-2.0-only */
 
#include <boardid.h>
#include <bootmode.h>
#include <boot/coreboot_tables.h>
#include <console/console.h>
#include <delay.h>
#include <drivers/i2c/ww_ring/ww_ring.h>
#include <gpio.h>
#include <soc/cdp.h>
#include <soc/gsbi.h>
#include <timer.h>
 
#define DEV_SW 15
#define REC_SW 16
#define WP_SW  17
 
static int read_gpio(gpio_t gpio_num)
{
        gpio_tlmm_config_set(gpio_num, GPIO_FUNC_DISABLE,
                             GPIO_NO_PULL, GPIO_2MA, GPIO_DISABLE);
        udelay(10); /* Should be enough to settle. */
        return gpio_get(gpio_num);
}
 
void fill_lb_gpios(struct lb_gpios *gpios)
{
        struct lb_gpio chromeos_gpios[] = {
                {DEV_SW, ACTIVE_LOW, read_gpio(REC_SW), "presence"},
                {-1, ACTIVE_LOW, 1, "power"},
                {-1, ACTIVE_LOW, 0, "lid"},
        };
        lb_add_gpios(gpios, chromeos_gpios, ARRAY_SIZE(chromeos_gpios));
}
 
/*
 * The recovery switch on storm is overloaded: it needs to be pressed for a
 * certain duration at startup to signal different requests:
 *
 * - keeping it pressed for 8 to 16 seconds after startup signals the need for
 *   factory reset (wipeout);
 * - keeping it pressed for longer than 16 seconds signals the need for Chrome
 *   OS recovery.
 *
 * The state is read once and cached for following inquiries. The below enum
 * lists possible states.
 */
enum switch_state {
        not_probed = -1,
        no_req,
        recovery_req,
        wipeout_req
};
 
static void display_pattern(int pattern)
{
        if (board_id() == BOARD_ID_WHIRLWIND_SP5)
                ww_ring_display_pattern(GSBI_ID_7, pattern);
}
 
#define WIPEOUT_MODE_DELAY_MS (8 * 1000)
#define RECOVERY_MODE_EXTRA_DELAY_MS (8 * 1000)
 
static enum switch_state get_switch_state(void)
{
        struct stopwatch sw;
        int sampled_value;
        static enum switch_state saved_state = not_probed;
 
        if (saved_state != not_probed)
                return saved_state;
 
        sampled_value = !read_gpio(REC_SW);
 
        if (!sampled_value) {
                saved_state = no_req;
                display_pattern(WWR_NORMAL_BOOT);
                return saved_state;
        }
 
        display_pattern(WWR_RECOVERY_PUSHED);
        printk(BIOS_INFO, "recovery button pressed\n");
 
        stopwatch_init_msecs_expire(&sw, WIPEOUT_MODE_DELAY_MS);
 
        do {
                sampled_value = !read_gpio(REC_SW);
                if (!sampled_value)
                        break;
        } while (!stopwatch_expired(&sw));
 
        if (sampled_value) {
                display_pattern(WWR_WIPEOUT_REQUEST);
                printk(BIOS_INFO, "wipeout requested, checking recovery\n");
                stopwatch_init_msecs_expire(&sw, RECOVERY_MODE_EXTRA_DELAY_MS);
                do {
                        sampled_value = !read_gpio(REC_SW);
                        if (!sampled_value)
                                break;
                } while (!stopwatch_expired(&sw));
 
                if (sampled_value) {
                        saved_state = recovery_req;
                        display_pattern(WWR_RECOVERY_REQUEST);
                        printk(BIOS_INFO, "recovery requested\n");
                } else {
                        saved_state = wipeout_req;
                }
        } else {
                saved_state = no_req;
                display_pattern(WWR_NORMAL_BOOT);
        }
 
        return saved_state;
}
 
int get_recovery_mode_switch(void)
{
        return get_switch_state() == recovery_req;
}
 
int get_wipeout_mode_switch(void)
{
        return get_switch_state() == wipeout_req;
}
 
int get_write_protect_state(void)
{
        return !read_gpio(WP_SW);
}
 
int get_ec_is_trusted(void)
{
        /* Do not have a Chrome EC involved in entering recovery mode;
           Always return trusted. */
        return 1;
}