// SPDX-License-Identifier: BSD-2-Clause
/*
 * fdt_helper.c - Flat Device Tree manipulation helper routines
 * Implement helper routines on top of libfdt for OpenSBI usage
 *
 * Copyright (C) 2020 Bin Meng <bmeng.cn@gmail.com>
 */

#include <libfdt.h>
#include <sbi/riscv_asm.h>
#include <sbi/sbi_console.h>
#include <sbi/sbi_hartmask.h>
#include <sbi/sbi_platform.h>
#include <sbi/sbi_scratch.h>
#include <sbi_utils/fdt/fdt_helper.h>
#include <sbi_utils/irqchip/plic.h>

#define DEFAULT_UART_FREQ		0
#define DEFAULT_UART_BAUD		115200
#define DEFAULT_UART_REG_SHIFT		0
#define DEFAULT_UART_REG_IO_WIDTH	1

#define DEFAULT_SIFIVE_UART_FREQ		0
#define DEFAULT_SIFIVE_UART_BAUD		115200
#define DEFAULT_SIFIVE_UART_REG_SHIFT		0
#define DEFAULT_SIFIVE_UART_REG_IO_WIDTH	4

#define DEFAULT_GAISLER_UART_REG_IO_WIDTH	4

#define DEFAULT_SHAKTI_UART_FREQ		50000000
#define DEFAULT_SHAKTI_UART_BAUD		115200

const struct fdt_match *fdt_match_node(void *fdt, int nodeoff,
				       const struct fdt_match *match_table)
{
	int ret;

	if (!fdt || nodeoff < 0 || !match_table)
		return NULL;

	while (match_table->compatible) {
		ret = fdt_node_check_compatible(fdt, nodeoff,
						match_table->compatible);
		if (!ret)
			return match_table;
		match_table++;
	}

	return NULL;
}

int fdt_find_match(void *fdt, int startoff,
		   const struct fdt_match *match_table,
		   const struct fdt_match **out_match)
{
	int nodeoff;

	if (!fdt || !match_table)
		return SBI_ENODEV;

	while (match_table->compatible) {
		nodeoff = fdt_node_offset_by_compatible(fdt, startoff,
						match_table->compatible);
		if (nodeoff >= 0) {
			if (out_match)
				*out_match = match_table;
			return nodeoff;
		}
		match_table++;
	}

	return SBI_ENODEV;
}

int fdt_parse_phandle_with_args(void *fdt, int nodeoff,
				const char *prop, const char *cells_prop,
				int index, struct fdt_phandle_args *out_args)
{
	u32 i, pcells;
	int len, pnodeoff;
	const fdt32_t *list, *list_end, *val;

	if (!fdt || (nodeoff < 0) || !prop || !cells_prop || !out_args)
		return SBI_EINVAL;

	list = fdt_getprop(fdt, nodeoff, prop, &len);
	if (!list)
		return SBI_ENOENT;
	list_end = list + (len / sizeof(*list));

	while (list < list_end) {
		pnodeoff = fdt_node_offset_by_phandle(fdt,
						fdt32_to_cpu(*list));
		if (pnodeoff < 0)
			return pnodeoff;
		list++;

		val = fdt_getprop(fdt, pnodeoff, cells_prop, &len);
		if (!val)
			return SBI_ENOENT;
		pcells = fdt32_to_cpu(*val);
		if (FDT_MAX_PHANDLE_ARGS < pcells)
			return SBI_EINVAL;
		if (list + pcells > list_end)
			return SBI_ENOENT;

		if (index > 0) {
			list += pcells;
			index--;
		} else {
			out_args->node_offset = pnodeoff;
			out_args->args_count = pcells;
			for (i = 0; i < pcells; i++)
				out_args->args[i] = fdt32_to_cpu(list[i]);
			return 0;
		}
	}

	return SBI_ENOENT;
}

static int fdt_translate_address(void *fdt, uint64_t reg, int parent,
				 uint64_t *addr)
{
	int i, rlen;
	int cell_addr, cell_size;
	const fdt32_t *ranges;
	uint64_t offset = 0, caddr = 0, paddr = 0, rsize = 0;

	cell_addr = fdt_address_cells(fdt, parent);
	if (cell_addr < 1)
		return SBI_ENODEV;

	cell_size = fdt_size_cells(fdt, parent);
	if (cell_size < 0)
		return SBI_ENODEV;

	ranges = fdt_getprop(fdt, parent, "ranges", &rlen);
	if (ranges && rlen > 0) {
		for (i = 0; i < cell_addr; i++)
			caddr = (caddr << 32) | fdt32_to_cpu(*ranges++);
		for (i = 0; i < cell_addr; i++)
			paddr = (paddr << 32) | fdt32_to_cpu(*ranges++);
		for (i = 0; i < cell_size; i++)
			rsize = (rsize << 32) | fdt32_to_cpu(*ranges++);
		if (reg < caddr || caddr >= (reg + rsize )) {
			sbi_printf("invalid address translation\n");
			return SBI_ENODEV;
		}
		offset = reg - caddr;
		*addr = paddr + offset;
	} else {
		/* No translation required */
		*addr = reg;
	}

	return 0;
}

int fdt_get_node_addr_size(void *fdt, int node, int index,
			   uint64_t *addr, uint64_t *size)
{
	int parent, len, i, rc;
	int cell_addr, cell_size;
	const fdt32_t *prop_addr, *prop_size;
	uint64_t temp = 0;

	if (!fdt || node < 0 || index < 0)
		return SBI_EINVAL;

	parent = fdt_parent_offset(fdt, node);
	if (parent < 0)
		return parent;
	cell_addr = fdt_address_cells(fdt, parent);
	if (cell_addr < 1)
		return SBI_ENODEV;

	cell_size = fdt_size_cells(fdt, parent);
	if (cell_size < 0)
		return SBI_ENODEV;

	prop_addr = fdt_getprop(fdt, node, "reg", &len);
	if (!prop_addr)
		return SBI_ENODEV;

	if ((len / sizeof(u32)) <= (index * (cell_addr + cell_size)))
		return SBI_EINVAL;

	prop_addr = prop_addr + (index * (cell_addr + cell_size));
	prop_size = prop_addr + cell_addr;

	if (addr) {
		for (i = 0; i < cell_addr; i++)
			temp = (temp << 32) | fdt32_to_cpu(*prop_addr++);
		do {
			if (parent < 0)
				break;
			rc  = fdt_translate_address(fdt, temp, parent, addr);
			if (rc)
				break;
			parent = fdt_parent_offset(fdt, parent);
			temp = *addr;
		} while (1);
	}
	temp = 0;

	if (size) {
		for (i = 0; i < cell_size; i++)
			temp = (temp << 32) | fdt32_to_cpu(*prop_size++);
		*size = temp;
	}

	return 0;
}

int fdt_parse_hart_id(void *fdt, int cpu_offset, u32 *hartid)
{
	int len;
	const void *prop;
	const fdt32_t *val;

	if (!fdt || cpu_offset < 0)
		return SBI_EINVAL;

	prop = fdt_getprop(fdt, cpu_offset, "device_type", &len);
	if (!prop || !len)
		return SBI_EINVAL;
	if (strncmp (prop, "cpu", strlen ("cpu")))
		return SBI_EINVAL;

	val = fdt_getprop(fdt, cpu_offset, "reg", &len);
	if (!val || len < sizeof(fdt32_t))
		return SBI_EINVAL;

	if (len > sizeof(fdt32_t))
		val++;

	if (hartid)
		*hartid = fdt32_to_cpu(*val);

	return 0;
}

int fdt_parse_max_hart_id(void *fdt, u32 *max_hartid)
{
	u32 hartid;
	int err, cpu_offset, cpus_offset;

	if (!fdt)
		return SBI_EINVAL;
	if (!max_hartid)
		return 0;

	*max_hartid = 0;

	cpus_offset = fdt_path_offset(fdt, "/cpus");
	if (cpus_offset < 0)
		return cpus_offset;

	fdt_for_each_subnode(cpu_offset, fdt, cpus_offset) {
		err = fdt_parse_hart_id(fdt, cpu_offset, &hartid);
		if (err)
			continue;

		if (hartid > *max_hartid)
			*max_hartid = hartid;
	}

	return 0;
}

int fdt_parse_timebase_frequency(void *fdt, unsigned long *freq)
{
	const fdt32_t *val;
	int len, cpus_offset;

	if (!fdt || !freq)
		return SBI_EINVAL;

	cpus_offset = fdt_path_offset(fdt, "/cpus");
	if (cpus_offset < 0)
		return cpus_offset;

	val = fdt_getprop(fdt, cpus_offset, "timebase-frequency", &len);
	if (len > 0 && val)
		*freq = fdt32_to_cpu(*val);
	else
		return SBI_ENOENT;

	return 0;
}

int fdt_parse_gaisler_uart_node(void *fdt, int nodeoffset,
				struct platform_uart_data *uart)
{
	int len, rc;
	const fdt32_t *val;
	uint64_t reg_addr, reg_size;

	if (nodeoffset < 0 || !uart || !fdt)
		return SBI_ENODEV;

	rc = fdt_get_node_addr_size(fdt, nodeoffset, 0,
				    &reg_addr, &reg_size);
	if (rc < 0 || !reg_addr || !reg_size)
		return SBI_ENODEV;
	uart->addr = reg_addr;

	/**
	 * UART address is mandatory. clock-frequency and current-speed
	 * may not be present. Don't return error.
	 */
	val = (fdt32_t *)fdt_getprop(fdt, nodeoffset, "clock-frequency", &len);
	if (len > 0 && val)
		uart->freq = fdt32_to_cpu(*val);
	else
		uart->freq = DEFAULT_UART_FREQ;

	val = (fdt32_t *)fdt_getprop(fdt, nodeoffset, "current-speed", &len);
	if (len > 0 && val)
		uart->baud = fdt32_to_cpu(*val);
	else
		uart->baud = DEFAULT_UART_BAUD;

	/* For Gaisler APBUART, the reg-shift and reg-io-width are fixed .*/
	uart->reg_shift	   = DEFAULT_UART_REG_SHIFT;
	uart->reg_io_width = DEFAULT_GAISLER_UART_REG_IO_WIDTH;

	return 0;
}

int fdt_parse_shakti_uart_node(void *fdt, int nodeoffset,
			       struct platform_uart_data *uart)
{
	int len, rc;
	const fdt32_t *val;
	uint64_t reg_addr, reg_size;

	if (nodeoffset < 0 || !uart || !fdt)
		return SBI_ENODEV;

	rc = fdt_get_node_addr_size(fdt, nodeoffset, 0,
				    &reg_addr, &reg_size);
	if (rc < 0 || !reg_addr || !reg_size)
		return SBI_ENODEV;
	uart->addr = reg_addr;

	/**
	 * UART address is mandaotry. clock-frequency and current-speed
	 * may not be present. Don't return error.
	 */
	val = (fdt32_t *)fdt_getprop(fdt, nodeoffset, "clock-frequency", &len);
	if (len > 0 && val)
		uart->freq = fdt32_to_cpu(*val);
	else
		uart->freq = DEFAULT_SHAKTI_UART_FREQ;

	val = (fdt32_t *)fdt_getprop(fdt, nodeoffset, "current-speed", &len);
	if (len > 0 && val)
		uart->baud = fdt32_to_cpu(*val);
	else
		uart->baud = DEFAULT_SHAKTI_UART_BAUD;

	return 0;
}

int fdt_parse_sifive_uart_node(void *fdt, int nodeoffset,
			       struct platform_uart_data *uart)
{
	int len, rc;
	const fdt32_t *val;
	uint64_t reg_addr, reg_size;

	if (nodeoffset < 0 || !uart || !fdt)
		return SBI_ENODEV;

	rc = fdt_get_node_addr_size(fdt, nodeoffset, 0,
				    &reg_addr, &reg_size);
	if (rc < 0 || !reg_addr || !reg_size)
		return SBI_ENODEV;
	uart->addr = reg_addr;

	/**
	 * UART address is mandaotry. clock-frequency and current-speed
	 * may not be present. Don't return error.
	 */
	val = (fdt32_t *)fdt_getprop(fdt, nodeoffset, "clock-frequency", &len);
	if (len > 0 && val)
		uart->freq = fdt32_to_cpu(*val);
	else
		uart->freq = DEFAULT_SIFIVE_UART_FREQ;

	val = (fdt32_t *)fdt_getprop(fdt, nodeoffset, "current-speed", &len);
	if (len > 0 && val)
		uart->baud = fdt32_to_cpu(*val);
	else
		uart->baud = DEFAULT_SIFIVE_UART_BAUD;

	/* For SiFive UART, the reg-shift and reg-io-width are fixed .*/
	uart->reg_shift = DEFAULT_SIFIVE_UART_REG_SHIFT;
	uart->reg_io_width = DEFAULT_SIFIVE_UART_REG_IO_WIDTH;

	return 0;
}

int fdt_parse_uart8250_node(void *fdt, int nodeoffset,
			    struct platform_uart_data *uart)
{
	int len, rc;
	const fdt32_t *val;
	uint64_t reg_addr, reg_size;

	if (nodeoffset < 0 || !uart || !fdt)
		return SBI_ENODEV;

	rc = fdt_get_node_addr_size(fdt, nodeoffset, 0,
				    &reg_addr, &reg_size);
	if (rc < 0 || !reg_addr || !reg_size)
		return SBI_ENODEV;
	uart->addr = reg_addr;

	/**
	 * UART address is mandaotry. clock-frequency and current-speed
	 * may not be present. Don't return error.
	 */
	val = (fdt32_t *)fdt_getprop(fdt, nodeoffset, "clock-frequency", &len);
	if (len > 0 && val)
		uart->freq = fdt32_to_cpu(*val);
	else
		uart->freq = DEFAULT_UART_FREQ;

	val = (fdt32_t *)fdt_getprop(fdt, nodeoffset, "current-speed", &len);
	if (len > 0 && val)
		uart->baud = fdt32_to_cpu(*val);
	else
		uart->baud = DEFAULT_UART_BAUD;

	val = (fdt32_t *)fdt_getprop(fdt, nodeoffset, "reg-shift", &len);
	if (len > 0 && val)
		uart->reg_shift = fdt32_to_cpu(*val);
	else
		uart->reg_shift = DEFAULT_UART_REG_SHIFT;

	val = (fdt32_t *)fdt_getprop(fdt, nodeoffset, "reg-io-width", &len);
	if (len > 0 && val)
		uart->reg_io_width = fdt32_to_cpu(*val);
	else
		uart->reg_io_width = DEFAULT_UART_REG_IO_WIDTH;

	return 0;
}

int fdt_parse_uart8250(void *fdt, struct platform_uart_data *uart,
		   const char *compatible)
{
	int nodeoffset;

	if (!compatible || !uart || !fdt)
		return SBI_ENODEV;

	nodeoffset = fdt_node_offset_by_compatible(fdt, -1, compatible);
	if (nodeoffset < 0)
		return nodeoffset;

	return fdt_parse_uart8250_node(fdt, nodeoffset, uart);
}

int fdt_parse_plic_node(void *fdt, int nodeoffset, struct plic_data *plic)
{
	int len, rc;
	const fdt32_t *val;
	uint64_t reg_addr, reg_size;

	if (nodeoffset < 0 || !plic || !fdt)
		return SBI_ENODEV;

	rc = fdt_get_node_addr_size(fdt, nodeoffset, 0,
				    &reg_addr, &reg_size);
	if (rc < 0 || !reg_addr || !reg_size)
		return SBI_ENODEV;
	plic->addr = reg_addr;

	val = fdt_getprop(fdt, nodeoffset, "riscv,ndev", &len);
	if (len > 0)
		plic->num_src = fdt32_to_cpu(*val);

	return 0;
}

int fdt_parse_plic(void *fdt, struct plic_data *plic, const char *compat)
{
	int nodeoffset;

	if (!compat || !plic || !fdt)
		return SBI_ENODEV;

	nodeoffset = fdt_node_offset_by_compatible(fdt, -1, compat);
	if (nodeoffset < 0)
		return nodeoffset;

	return fdt_parse_plic_node(fdt, nodeoffset, plic);
}

int fdt_parse_aclint_node(void *fdt, int nodeoffset, bool for_timer,
			  unsigned long *out_addr1, unsigned long *out_size1,
			  unsigned long *out_addr2, unsigned long *out_size2,
			  u32 *out_first_hartid, u32 *out_hart_count)
{
	const fdt32_t *val;
	uint64_t reg_addr, reg_size;
	int i, rc, count, cpu_offset, cpu_intc_offset;
	u32 phandle, hwirq, hartid, first_hartid, last_hartid, hart_count;
	u32 match_hwirq = (for_timer) ? IRQ_M_TIMER : IRQ_M_SOFT;

	if (nodeoffset < 0 || !fdt ||
	    !out_addr1 || !out_size1 ||
	    !out_first_hartid || !out_hart_count)
		return SBI_EINVAL;

	rc = fdt_get_node_addr_size(fdt, nodeoffset, 0,
				    &reg_addr, &reg_size);
	if (rc < 0 || !reg_size)
		return SBI_ENODEV;
	*out_addr1 = reg_addr;
	*out_size1 = reg_size;

	rc = fdt_get_node_addr_size(fdt, nodeoffset, 1,
				    &reg_addr, &reg_size);
	if (rc < 0 || !reg_size)
		reg_addr = reg_size = 0;
	if (out_addr2)
		*out_addr2 = reg_addr;
	if (out_size2)
		*out_size2 = reg_size;

	*out_first_hartid = 0;
	*out_hart_count = 0;

	val = fdt_getprop(fdt, nodeoffset, "interrupts-extended", &count);
	if (!val || count < sizeof(fdt32_t))
		return 0;
	count = count / sizeof(fdt32_t);

	first_hartid = -1U;
	hart_count = last_hartid = 0;
	for (i = 0; i < (count / 2); i++) {
		phandle = fdt32_to_cpu(val[2 * i]);
		hwirq = fdt32_to_cpu(val[(2 * i) + 1]);

		cpu_intc_offset = fdt_node_offset_by_phandle(fdt, phandle);
		if (cpu_intc_offset < 0)
			continue;

		cpu_offset = fdt_parent_offset(fdt, cpu_intc_offset);
		if (cpu_intc_offset < 0)
			continue;

		rc = fdt_parse_hart_id(fdt, cpu_offset, &hartid);
		if (rc)
			continue;

		if (SBI_HARTMASK_MAX_BITS <= hartid)
			continue;

		if (match_hwirq == hwirq) {
			if (hartid < first_hartid)
				first_hartid = hartid;
			if (hartid > last_hartid)
				last_hartid = hartid;
			hart_count++;
		}
	}

	if ((last_hartid >= first_hartid) && first_hartid != -1U) {
		*out_first_hartid = first_hartid;
		count = last_hartid - first_hartid + 1;
		*out_hart_count = (hart_count < count) ? hart_count : count;
	}

	return 0;
}

int fdt_parse_compat_addr(void *fdt, uint64_t *addr,
			  const char *compatible)
{
	int nodeoffset, rc;

	nodeoffset = fdt_node_offset_by_compatible(fdt, -1, compatible);
	if (nodeoffset < 0)
		return nodeoffset;

	rc = fdt_get_node_addr_size(fdt, nodeoffset, 0, addr, NULL);
	if (rc < 0 || !addr)
		return SBI_ENODEV;

	return 0;
}