#include <linux/init.h>
#include <linux/kconfig.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/env.h>
#include <linux/genhd.h>
#include <linux/pagemap.h>
#include <linux/delay.h>
#include <linux/mount.h>
#include <linux/blkdev.h>

#include <asm/prom.h>

#include <avm/enh/fw_info.h>


/*----------------------------------------------------------------------------*\
\*----------------------------------------------------------------------------*/
#if IS_ENABLED(CONFIG_OF_AVM_DT_ENV)
#include <linux/of_fdt.h>
#include <linux/of.h>
#include <linux/of_platform.h>
/*
 *  Retrieves the AVM Environment Variables from the Device Tree
 */
char *__must_check prom_getenv_device_tree(char *envname)
{
	/* Check if we have a device tree */
	if (of_have_populated_dt()) {
		struct device_node *node;
		char *string = 0;
		/* Go to the chosen node where the environment is stored */
		node =  of_find_node_by_path("/chosen");
		if (!node) {
			pr_err("Chosen node not found\n");
			return 0;
		}
		/* check if the is a property with the name specified by
		 * envname
		 */
		if (of_property_read_string(node, envname,
					(const char **) &string) == 0) {
			pr_debug("Found env %s\n", string);
			return string;
		}

		pr_err("Could not find Env '%s' in the device tree\n", envname);
		return 0;
	}

	pr_err("Device Tree not populated\n");
	return NULL;
}

#else
/* === Support for old urlader env mechanism used for scorpion et al. === */
#include <asm/prom.h>

char *dst_env[64 * 2] __attribute__ ((section(".init.data")));
char *dst_config[4] __attribute__ ((section(".init.data")));
char dst_env_buff[2048] __attribute__((section(".init.data")));
char *dst_cmdline[COMMAND_LINE_SIZE] __attribute__ ((section(".init.data")));
char dst_cmdline_buff[64 * 1024] __attribute__((section(".init.data")));

/* --- #define DEBUG_PROM_INIT --- */

#if defined(DEBUG_PROM_INIT)
#define PROM_PRINTK(...) printk(__VA_ARGS__)
#else
#define PROM_PRINTK(...)
#endif

#define prom_envp(index) ((char *)(long)_prom_envp[(index)])

static char env_buffer[2048];
static char *_local_envp[64 * 2];
unsigned int fritz_box_hw_revision;
int *_prom_envp;

#if defined(DEBUG_PROM_INIT)
void print_env(char **myenv)
{
	int i = 0;

	PROM_PRINTK("myenvp=%p\n", myenv);
	while (myenv[i] && myenv[i+1]) {
		PROM_PRINTK("(%p)%s : (%p)%s\n", myenv[i], myenv[i], myenv[i+1], myenv[i+1]);
		i += 2;
	}
}

#if defined(CONFIG_MIPS)
void print_cmdline(int argc, char **argv)
{

	int i = 0;

	PROM_PRINTK("argc=%d argv=%p\n", argc, argv);
	for (i = 0; i < argc; i++) {
		PROM_PRINTK("[%d]: %s\n", i, argv[i]);
	}
}
#include <asm/bootinfo.h>
#endif /*--- #if defined(CONFIG_MIPS) ---*/
#endif /*--- #if defined(DEBUG_PROM_INIT) ---*/

void __init env_init(int *fw_arg2, enum _env_location env_location)
{
	unsigned int i;
	char *p;
	struct _avm_kernel_urlader_env *urlader_env;
	static unsigned int once;

	if (once)
		return;
	once = 1;

	if (env_location == ENV_LOCATION_AVM_CONF) {
		urlader_env = (struct _avm_kernel_urlader_env *) fw_arg2;
		for (i = 0; urlader_env[i].name[0] && i < 64; i++) {
			_local_envp[2 * i] = (urlader_env[i].name);
			_local_envp[2 * i + 1] = (urlader_env[i].value);
		}
		i *= 2;
	} else {
		_prom_envp = fw_arg2;

#if defined(DEBUG_PROM_INIT)
		print_env((char **)_prom_envp);
#if defined(CONFIG_MIPS)
		print_cmdline(fw_arg0, (char **)fw_arg1);
#endif /*--- #if defined(CONFIG_MIPS) ---*/
#endif /*--- #if defined(DEBUG_PROM_INIT) ---*/

		PROM_PRINTK("[prom_init] 0\n");

		env_buffer[0] = '\0';
		p = env_buffer;

		/* copy envp values from urlader memory to (non init) kernel
		 * memory.
		 */
		for (i = 0 ; _prom_envp && _prom_envp[i] && _prom_envp[i + 1] ; i += 2) {
#if defined(DEBUG_PROM_INIT)
			PROM_PRINTK("[prom_init] envp[%u]= \"%s\"=\"%s\"\n", i, (char *)_prom_envp[i], (char *)_prom_envp[i + 1]);
#endif /*--- #if defined(DEBUG_PROM_INIT) ---*/
			_local_envp[i] = p;
			strcat(p, (char *)(_prom_envp[i]));
			p += strlen((char *)(_prom_envp[i])) + 1;
			/*--- align auf naechstes wort ---*/
			while ((unsigned int)p & 0x3)
				*p++ = '\0';

			_local_envp[i + 1] = p;
			switch (env_location) {
			case ENV_LOCATION_FLASH:
				strcat(p, (char *)_prom_envp[i + 1]);
				p += strlen((char *)_prom_envp[i + 1]) + 1;
				break;
			case ENV_LOCATION_PHY_RAM:
				strcat(p, (char *)phys_to_virt(_prom_envp[i + 1]));
				p += strlen((char *)phys_to_virt(_prom_envp[i + 1])) + 1;
				break;
			case ENV_LOCATION_VIRT_RAM:
				strcat(p, (char *)(_prom_envp[i + 1]));
				p += strlen((char *)(_prom_envp[i + 1])) + 1;
				break;
			case ENV_LOCATION_AVM_CONF:
				/* Can not happen !! */
				break;
			}
			/*--- align auf naechstes wort ---*/
			while ((unsigned int)p & 0x3)
				*p++ = '\0';
		}
	}
	_local_envp[i] = NULL;
	_local_envp[i + 1] = NULL;
	_prom_envp = (int *)_local_envp;

	fritz_box_hw_revision = simple_strtoul(prom_getenv("HWRevision"),
			NULL, 10);
}
#endif


char *__must_check prom_getenv(char *envname)
{
	/*
	 * Return a pointer to the given environment variable.
	 * In 64-bit mode: we're using 64-bit pointers, but all pointers
	 * in the PROM structures are only 32-bit, so we need some
	 * workarounds, if we are running in 64-bit mode.
	 */

#if IS_ENABLED(CONFIG_OF_AVM_DT_ENV)
	pr_debug("Retrieving %s from device tree\n", envname);
	return prom_getenv_device_tree(envname);
#else
	int i, index = 0;

	if (!_prom_envp)
		return NULL;

	i = strlen(envname);

	while (prom_envp(index)) {
		if (strncmp(envname, prom_envp(index), i) == 0) {
			return prom_envp(index+1);
		}
		index += 2;
	}

	return NULL;
#endif
}
EXPORT_SYMBOL(prom_getenv);