#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <asm/prom.h>
#include <linux/avm_hw_config.h>
#include <linux/of_avm_dt.h>
#include <linux/errno.h>
#include <linux/of_fdt.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/bootmem.h>
#include <linux/memblock.h>
#include <linux/slab.h>
//#include <linux/avm_hw_config_def.h>

/*
 * Reads the GPIO config from an "avm,avm_gpio_generic" compatible node and
 * copies the data into the given struct _avm_hw_config
 */
static int read_avm_gpio_generic(struct device_node *gpio_node,
		struct _avm_hw_config *hw_cfg)
{
	const uint32_t *prop __maybe_unused;
	uint32_t prop_found, tmp, numElems __maybe_unused;
	int i;

	pr_debug("[%s] Called. gpio_node: %p hw_cfg: %p\n", __func__, gpio_node, hw_cfg);

	// clear target hw_cfg
	memset(hw_cfg, 0x0, sizeof(*hw_cfg));

	//read the name
	hw_cfg->name = (char *) of_get_property(gpio_node, "name", &i);
	pr_debug("[DTB] read gpio %s\n", hw_cfg->name);
	if (!(hw_cfg->name)) {
		//couldn't read name
		return -ENOMSG;
	}

	//read the value
	prop_found = of_property_read_u32(gpio_node, "value", &tmp);
	if (!prop_found) {
		hw_cfg->value = tmp;
	}

	//read the param
	prop_found = of_property_read_u32(gpio_node, "param", &tmp);
	if (!prop_found) {
		hw_cfg->param = tmp;
	} else {
		hw_cfg->param = avm_hw_param_no_param;
	}

#if defined(CONFIG_AVM_PWM)
	if (hw_cfg->param == avm_hw_param_gpio_out_rgb || hw_cfg->param == avm_hw_param_gpio_out_rgb_active_low) {
		prop_found = of_property_read_u32(gpio_node, "red", &tmp);
		if (!prop_found) {
			hw_cfg->rgb_gpio_red = tmp;
		}
		prop_found = of_property_read_u32(gpio_node, "green", &tmp);
		if (!prop_found) {
			hw_cfg->rgb_gpio_green = tmp;
		}
		prop_found = of_property_read_u32(gpio_node, "blue", &tmp);
		if (!prop_found) {
			hw_cfg->rgb_gpio_blue = tmp;
		}
	}
	prop_found = of_property_read_u32(gpio_node, "value_overwrite", &tmp);
	if (!prop_found) {
		hw_cfg->value_overwrite = tmp;
	} else {
		hw_cfg->value_overwrite = -1;
	}
#endif

	return 0;
}

/*
 * Finds all AVM GPIO Entries in the device tree and generates the hw_config_table from it
 */
int avm_generate_hw_config_table_from_device_tree(void)
{
	struct device_node *node;
	uint8_t populated;
	int gpio_cnt, result;
	const char *of_compatible = "avm,avm_gpio_generic";
	struct device_node *gpio_node;

	pr_err("Creating Config Table\n");
	//loop through device tree, find all avm gpios, count them, allocate memory
	populated = of_have_populated_dt();

	if (!populated) {
		pr_err("[DTB] No populated device tree found\n");
		mdelay(10);
		panic("[DTB] No populated device tree found\n");
	}

	gpio_cnt = 0;

	//loop over all compatible nodes, check there module_id and increment gpio_cnt if the module_id is greater than zero
	node = NULL;
	while (NULL != (node = of_find_compatible_node(node, NULL, of_compatible))) {
		gpio_cnt += of_get_child_count(node);
	}
	pr_debug("[%s] gpio_cnt: %d\n", __func__, gpio_cnt);

	// allocate one more GPIO than actually needed to have an end of config marker in the
	// config table, where the name is NULL
	avm_current_hw_config = kzalloc((gpio_cnt + 1) * sizeof(struct _avm_hw_config),
									GFP_KERNEL);
	if (!avm_current_hw_config) {
		panic("[DTB] Error allocating mem for config table\n");
	}

	// copy device tree data to hw_config
	if (gpio_cnt > 0) {
		gpio_cnt = 0;
		node = NULL;
		while (NULL != (node = of_find_compatible_node(node, NULL, of_compatible))) {
			for_each_child_of_node(node, gpio_node) {
				result = read_avm_gpio_generic(gpio_node,
											   &(avm_current_hw_config[gpio_cnt]));
				if (result != 0) {
					pr_err("[DTB] Error reading GPIO from device tree\n");
					return -ENOMSG;
				}

				gpio_cnt++;
			}
		}
	}

	pr_debug("[DTB] Found %i compatible gpios 'avm,avm_gpio_generic' with module_id>0\n",
			 gpio_cnt);
	pr_debug("[DTB] Device Table generated\n");

	init_gpio_config();

	pr_debug("[DTB] GPIOs configurated.\n");

	return 0;
}
postcore_initcall(avm_generate_hw_config_table_from_device_tree);

/*
 * Reads Interrupt Information from the Device Tree
 * Finds the Interrupt specified by irq_name and stores the information in cpu_used, cpu_mask and int_num
 * @param int_name: the name of the interrupt to find
 * @param cpu_used: pointer to store the cpu_used information
 * @param cpu_mask: pointer to store the cpu_mask information
 * @param int_num: pointer to store the int_num information
 */
int get_interrupt_info_from_device_tree(const char *int_name,
		int32_t *cpu_used, int32_t *cpu_mask,
		int32_t *int_num)
{
	struct device_node *node, *child;
	uint8_t populated;
	uint32_t prop_found;
	int len, result;
	char *namecmp;
	const char *of_compatible = "avm,avm_interrupt";

	result = -ENOENT;

	populated = of_have_populated_dt();
	if (!populated) {
		pr_debug("[%s]Device Tree not populated, cannot read interrupt information\n", __func__);
		result = -ENOMSG;
		goto err_out;
	}

	node = NULL;
	while (NULL != (node = of_find_compatible_node(node, NULL, of_compatible))
	      && result != 0) {
		for_each_child_of_node(node, child) {

			namecmp = (char *) of_get_property(child, "name", &len);
			if (namecmp == NULL) {
				continue;
			}

			if (strcmp(namecmp, int_name)) {
				continue;
			}

			//names match, read info
			if (cpu_used) {
				prop_found = of_property_read_u32(child, "cpu_used", cpu_used);
				if (prop_found) {
					pr_debug("[DTB] Couldn't read cpu_used property!\n");
					result = -ENOMSG;
					goto err_out;
				}
			}

			if (cpu_mask) {
				prop_found = of_property_read_u32(child, "cpu_mask", cpu_mask);
				if (prop_found) {
					pr_debug("[DTB] Couldn't read cpu_mask property!\n");
					result = -ENOMSG;
					goto err_out;
				}
			}

			if (int_num) {
				prop_found = of_property_read_u32(child, "int_num", int_num);
				if (prop_found) {
					pr_debug("[DTB] Couldn't read int_num property!\n");
					result = -ENOMSG;
					goto err_out;
				}
			}

			result = 0;
		}
	}

err_out:
	return result;
}