// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (c) 2011-2012 The Chromium OS Authors.
 */

#include <common.h>
#include <errno.h>
#include <fdtdec.h>
#include <os.h>
#include <asm/state.h>

/* Main state record for the sandbox */
static struct sandbox_state main_state;
static struct sandbox_state *state;     /* Pointer to current state record */

static int state_ensure_space(int extra_size)
{
        void *blob = state->state_fdt;
        int used, size, free;
        void *buf;
        int ret;

        used = fdt_off_dt_strings(blob) + fdt_size_dt_strings(blob);
        size = fdt_totalsize(blob);
        free = size - used;
        if (free > extra_size)
                return 0;

        size = used + extra_size;
        buf = os_malloc(size);
        if (!buf)
                return -ENOMEM;

        ret = fdt_open_into(blob, buf, size);
        if (ret) {
                os_free(buf);
                return -EIO;
        }

        os_free(blob);
        state->state_fdt = buf;
        return 0;
}

static int state_read_file(struct sandbox_state *state, const char *fname)
{
        loff_t size;
        int ret;
        int fd;

        ret = os_get_filesize(fname, &size);
        if (ret < 0) {
                printf("Cannot find sandbox state file '%s'\n", fname);
                return -ENOENT;
        }
        state->state_fdt = os_malloc(size);
        if (!state->state_fdt) {
                puts("No memory to read sandbox state\n");
                return -ENOMEM;
        }
        fd = os_open(fname, OS_O_RDONLY);
        if (fd < 0) {
                printf("Cannot open sandbox state file '%s'\n", fname);
                ret = -EPERM;
                goto err_open;
        }
        if (os_read(fd, state->state_fdt, size) != size) {
                printf("Cannot read sandbox state file '%s'\n", fname);
                ret = -EIO;
                goto err_read;
        }
        os_close(fd);

        return 0;
err_read:
        os_close(fd);
err_open:
        os_free(state->state_fdt);
        state->state_fdt = NULL;

        return ret;
}

/***
 * sandbox_read_state_nodes() - Read state associated with a driver
 *
 * This looks through all compatible nodes and calls the read function on
 * each one, to read in the state.
 *
 * If nothing is found, it still calls the read function once, to set up a
 * single global state for that driver.
 *
 * @state: Sandbox state
 * @io: Method to use for reading state
 * @blob: FDT containing state
 * @return 0 if OK, -EINVAL if the read function returned failure
 */
int sandbox_read_state_nodes(struct sandbox_state *state,
                             struct sandbox_state_io *io, const void *blob)
{
        int count;
        int node;
        int ret;

        debug("   - read %s\n", io->name);
        if (!io->read)
                return 0;

        node = -1;
        count = 0;
        while (blob) {
                node = fdt_node_offset_by_compatible(blob, node, io->compat);
                if (node < 0)
                        return 0;       /* No more */
                debug("   - read node '%s'\n", fdt_get_name(blob, node, NULL));
                ret = io->read(blob, node);
                if (ret) {
                        printf("Unable to read state for '%s'\n", io->compat);
                        return -EINVAL;
                }
                count++;
        }

        /*
         * If we got no saved state, call the read function once without a
         * node, to set up the global state.
         */
        if (count == 0) {
                debug("   - read global\n");
                ret = io->read(NULL, -1);
                if (ret) {
                        printf("Unable to read global state for '%s'\n",
                               io->name);
                        return -EINVAL;
                }
        }

        return 0;
}

int sandbox_read_state(struct sandbox_state *state, const char *fname)
{
        struct sandbox_state_io *io;
        const void *blob;
        bool got_err;
        int ret;

        if (state->read_state && fname) {
                ret = state_read_file(state, fname);
                if (ret == -ENOENT && state->ignore_missing_state_on_read)
                        ret = 0;
                if (ret)
                        return ret;
        }

        /* Call all the state read functions */
        got_err = false;
        blob = state->state_fdt;
        io = ll_entry_start(struct sandbox_state_io, state_io);
        for (; io < ll_entry_end(struct sandbox_state_io, state_io); io++) {
                ret = sandbox_read_state_nodes(state, io, blob);
                if (ret < 0)
                        got_err = true;
        }

        if (state->read_state && fname) {
                debug("Read sandbox state from '%s'%s\n", fname,
                      got_err ? " (with errors)" : "");
        }

        return got_err ? -1 : 0;
}

/***
 * sandbox_write_state_node() - Write state associated with a driver
 *
 * This calls the write function to write out global state for that driver.
 *
 * TODO(sjg@chromium.org): Support writing out state from multiple drivers
 * of the same time. We don't need this yet,and it will be much easier to
 * do when driver model is available.
 *
 * @state: Sandbox state
 * @io: Method to use for writing state
 * @return 0 if OK, -EIO if there is a fatal error (such as out of space
 * for adding the data), -EINVAL if the write function failed.
 */
int sandbox_write_state_node(struct sandbox_state *state,
                             struct sandbox_state_io *io)
{
        void *blob;
        int node;
        int ret;

        if (!io->write)
                return 0;

        ret = state_ensure_space(SANDBOX_STATE_MIN_SPACE);
        if (ret) {
                printf("Failed to add more space for state\n");
                return -EIO;
        }

        /* The blob location can change when the size increases */
        blob = state->state_fdt;
        node = fdt_node_offset_by_compatible(blob, -1, io->compat);
        if (node == -FDT_ERR_NOTFOUND) {
                node = fdt_add_subnode(blob, 0, io->name);
                if (node < 0) {
                        printf("Cannot create node '%s': %s\n", io->name,
                               fdt_strerror(node));
                        return -EIO;
                }

                if (fdt_setprop_string(blob, node, "compatible", io->compat)) {
                        puts("Cannot set compatible\n");
                        return -EIO;
                }
        } else if (node < 0) {
                printf("Cannot access node '%s': %s\n", io->name,
                       fdt_strerror(node));
                return -EIO;
        }
        debug("Write state for '%s' to node %d\n", io->compat, node);
        ret = io->write(blob, node);
        if (ret) {
                printf("Unable to write state for '%s'\n", io->compat);
                return -EINVAL;
        }

        return 0;
}

int sandbox_write_state(struct sandbox_state *state, const char *fname)
{
        struct sandbox_state_io *io;
        bool got_err;
        int size;
        int ret;
        int fd;

        /* Create a state FDT if we don't have one */
        if (!state->state_fdt) {
                size = 0x4000;
                state->state_fdt = os_malloc(size);
                if (!state->state_fdt) {
                        puts("No memory to create FDT\n");
                        return -ENOMEM;
                }
                ret = fdt_create_empty_tree(state->state_fdt, size);
                if (ret < 0) {
                        printf("Cannot create empty state FDT: %s\n",
                               fdt_strerror(ret));
                        ret = -EIO;
                        goto err_create;
                }
        }

        /* Call all the state write funtcions */
        got_err = false;
        io = ll_entry_start(struct sandbox_state_io, state_io);
        ret = 0;
        for (; io < ll_entry_end(struct sandbox_state_io, state_io); io++) {
                ret = sandbox_write_state_node(state, io);
                if (ret == -EIO)
                        break;
                else if (ret)
                        got_err = true;
        }

        if (ret == -EIO) {
                printf("Could not write sandbox state\n");
                goto err_create;
        }

        ret = fdt_pack(state->state_fdt);
        if (ret < 0) {
                printf("Cannot pack state FDT: %s\n", fdt_strerror(ret));
                ret = -EINVAL;
                goto err_create;
        }
        size = fdt_totalsize(state->state_fdt);
        fd = os_open(fname, OS_O_WRONLY | OS_O_CREAT);
        if (fd < 0) {
                printf("Cannot open sandbox state file '%s'\n", fname);
                ret = -EIO;
                goto err_create;
        }
        if (os_write(fd, state->state_fdt, size) != size) {
                printf("Cannot write sandbox state file '%s'\n", fname);
                ret = -EIO;
                goto err_write;
        }
        os_close(fd);

        debug("Wrote sandbox state to '%s'%s\n", fname,
              got_err ? " (with errors)" : "");

        return 0;
err_write:
        os_close(fd);
err_create:
        os_free(state->state_fdt);

        return ret;
}

int state_setprop(int node, const char *prop_name, const void *data, int size)
{
        void *blob;
        int len;
        int ret;

        fdt_getprop(state->state_fdt, node, prop_name, &len);

        /* Add space for the new property, its name and some overhead */
        ret = state_ensure_space(size - len + strlen(prop_name) + 32);
        if (ret)
                return ret;

        /* This should succeed, barring a mutiny */
        blob = state->state_fdt;
        ret = fdt_setprop(blob, node, prop_name, data, size);
        if (ret) {
                printf("%s: Unable to set property '%s' in node '%s': %s\n",
                       __func__, prop_name, fdt_get_name(blob, node, NULL),
                        fdt_strerror(ret));
                return -ENOSPC;
        }

        return 0;
}

struct sandbox_state *state_get_current(void)
{
        assert(state);
        return state;
}

void state_set_skip_delays(bool skip_delays)
{
        struct sandbox_state *state = state_get_current();

        state->skip_delays = skip_delays;
}

bool state_get_skip_delays(void)
{
        struct sandbox_state *state = state_get_current();

        return state->skip_delays;
}

void state_reset_for_test(struct sandbox_state *state)
{
        /* No reset yet, so mark it as such. Always allow power reset */
        state->last_sysreset = SYSRESET_COUNT;
        state->sysreset_allowed[SYSRESET_POWER] = true;

        memset(&state->wdt, '\0', sizeof(state->wdt));
        memset(state->spi, '\0', sizeof(state->spi));
}

int state_init(void)
{
        state = &main_state;

        state->ram_size = CONFIG_SYS_SDRAM_SIZE;
        state->ram_buf = os_malloc(state->ram_size);
        assert(state->ram_buf);

        state_reset_for_test(state);
        /*
         * Example of how to use GPIOs:
         *
         * sandbox_gpio_set_direction(170, 0);
         * sandbox_gpio_set_value(170, 0);
         */
        return 0;
}

int state_uninit(void)
{
        int err;

        state = &main_state;

        if (state->write_ram_buf && !state->ram_buf_rm) {
                err = os_write_ram_buf(state->ram_buf_fname);
                if (err) {
                        printf("Failed to write RAM buffer\n");
                        return err;
                }
        }

        if (state->write_state) {
                if (sandbox_write_state(state, state->state_fname)) {
                        printf("Failed to write sandbox state\n");
                        return -1;
                }
        }

        /* Delete this at the last moment so as not to upset gdb too much */
        if (state->jumped_fname)
                os_unlink(state->jumped_fname);

        if (state->state_fdt)
                os_free(state->state_fdt);
        memset(state, '\0', sizeof(*state));

        return 0;
}