// SPDX-License-Identifier: GPL-2.0-only
/*
 * Low-level I/O functions.
 *
 * Copyright (c) 2017-2020, Silicon Laboratories, Inc.
 * Copyright (c) 2010, ST-Ericsson
 */
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/slab.h>

#include "hwio.h"
#include "wfx.h"
#include "bus.h"
#include "traces.h"

/*
 * Internal helpers.
 *
 * About CONFIG_VMAP_STACK:
 * When CONFIG_VMAP_STACK is enabled, it is not possible to run DMA on stack
 * allocated data. Functions below that work with registers (aka functions
 * ending with "32") automatically reallocate buffers with kmalloc. However,
 * functions that work with arbitrary length buffers let's caller to handle
 * memory location. In doubt, enable CONFIG_DEBUG_SG to detect badly located
 * buffer.
 */

static int read32(struct wfx_dev *wdev, int reg, u32 *val)
{
	int ret;
	__le32 *tmp = kmalloc(sizeof(u32), GFP_KERNEL);

	*val = ~0; /* Never return undefined value */
	if (!tmp)
		return -ENOMEM;
	ret = wdev->hwbus_ops->copy_from_io(wdev->hwbus_priv, reg, tmp,
					    sizeof(u32));
	if (ret >= 0)
		*val = le32_to_cpu(*tmp);
	kfree(tmp);
	if (ret)
		dev_err(wdev->dev, "%s: bus communication error: %d\n",
			__func__, ret);
	return ret;
}

static int write32(struct wfx_dev *wdev, int reg, u32 val)
{
	int ret;
	__le32 *tmp = kmalloc(sizeof(u32), GFP_KERNEL);

	if (!tmp)
		return -ENOMEM;
	*tmp = cpu_to_le32(val);
	ret = wdev->hwbus_ops->copy_to_io(wdev->hwbus_priv, reg, tmp,
					  sizeof(u32));
	kfree(tmp);
	if (ret)
		dev_err(wdev->dev, "%s: bus communication error: %d\n",
			__func__, ret);
	return ret;
}

static int read32_locked(struct wfx_dev *wdev, int reg, u32 *val)
{
	int ret;

	wdev->hwbus_ops->lock(wdev->hwbus_priv);
	ret = read32(wdev, reg, val);
	_trace_io_read32(reg, *val);
	wdev->hwbus_ops->unlock(wdev->hwbus_priv);
	return ret;
}

static int write32_locked(struct wfx_dev *wdev, int reg, u32 val)
{
	int ret;

	wdev->hwbus_ops->lock(wdev->hwbus_priv);
	ret = write32(wdev, reg, val);
	_trace_io_write32(reg, val);
	wdev->hwbus_ops->unlock(wdev->hwbus_priv);
	return ret;
}

static int write32_bits_locked(struct wfx_dev *wdev, int reg, u32 mask, u32 val)
{
	int ret;
	u32 val_r, val_w;

	WARN_ON(~mask & val);
	val &= mask;
	wdev->hwbus_ops->lock(wdev->hwbus_priv);
	ret = read32(wdev, reg, &val_r);
	_trace_io_read32(reg, val_r);
	if (ret < 0)
		goto err;
	val_w = (val_r & ~mask) | val;
	if (val_w != val_r) {
		ret = write32(wdev, reg, val_w);
		_trace_io_write32(reg, val_w);
	}
err:
	wdev->hwbus_ops->unlock(wdev->hwbus_priv);
	return ret;
}

static int indirect_read(struct wfx_dev *wdev, int reg, u32 addr,
			 void *buf, size_t len)
{
	int ret;
	int i;
	u32 cfg;
	u32 prefetch;

	WARN_ON(len >= 0x2000);
	WARN_ON(reg != WFX_REG_AHB_DPORT && reg != WFX_REG_SRAM_DPORT);

	if (reg == WFX_REG_AHB_DPORT)
		prefetch = CFG_PREFETCH_AHB;
	else if (reg == WFX_REG_SRAM_DPORT)
		prefetch = CFG_PREFETCH_SRAM;
	else
		return -ENODEV;

	ret = write32(wdev, WFX_REG_BASE_ADDR, addr);
	if (ret < 0)
		goto err;

	ret = read32(wdev, WFX_REG_CONFIG, &cfg);
	if (ret < 0)
		goto err;

	ret = write32(wdev, WFX_REG_CONFIG, cfg | prefetch);
	if (ret < 0)
		goto err;

	for (i = 0; i < 20; i++) {
		ret = read32(wdev, WFX_REG_CONFIG, &cfg);
		if (ret < 0)
			goto err;
		if (!(cfg & prefetch))
			break;
		usleep_range(200, 250);
	}
	if (i == 20) {
		ret = -ETIMEDOUT;
		goto err;
	}

	ret = wdev->hwbus_ops->copy_from_io(wdev->hwbus_priv, reg, buf, len);

err:
	if (ret < 0)
		memset(buf, 0xFF, len); /* Never return undefined value */
	return ret;
}

static int indirect_write(struct wfx_dev *wdev, int reg, u32 addr,
			  const void *buf, size_t len)
{
	int ret;

	WARN_ON(len >= 0x2000);
	WARN_ON(reg != WFX_REG_AHB_DPORT && reg != WFX_REG_SRAM_DPORT);
	ret = write32(wdev, WFX_REG_BASE_ADDR, addr);
	if (ret < 0)
		return ret;

	return wdev->hwbus_ops->copy_to_io(wdev->hwbus_priv, reg, buf, len);
}

static int indirect_read_locked(struct wfx_dev *wdev, int reg, u32 addr,
				void *buf, size_t len)
{
	int ret;

	wdev->hwbus_ops->lock(wdev->hwbus_priv);
	ret = indirect_read(wdev, reg, addr, buf, len);
	_trace_io_ind_read(reg, addr, buf, len);
	wdev->hwbus_ops->unlock(wdev->hwbus_priv);
	return ret;
}

static int indirect_write_locked(struct wfx_dev *wdev, int reg, u32 addr,
				 const void *buf, size_t len)
{
	int ret;

	wdev->hwbus_ops->lock(wdev->hwbus_priv);
	ret = indirect_write(wdev, reg, addr, buf, len);
	_trace_io_ind_write(reg, addr, buf, len);
	wdev->hwbus_ops->unlock(wdev->hwbus_priv);
	return ret;
}

static int indirect_read32_locked(struct wfx_dev *wdev, int reg,
				  u32 addr, u32 *val)
{
	int ret;
	__le32 *tmp = kmalloc(sizeof(u32), GFP_KERNEL);

	if (!tmp)
		return -ENOMEM;
	wdev->hwbus_ops->lock(wdev->hwbus_priv);
	ret = indirect_read(wdev, reg, addr, tmp, sizeof(u32));
	*val = le32_to_cpu(*tmp);
	_trace_io_ind_read32(reg, addr, *val);
	wdev->hwbus_ops->unlock(wdev->hwbus_priv);
	kfree(tmp);
	return ret;
}

static int indirect_write32_locked(struct wfx_dev *wdev, int reg,
				   u32 addr, u32 val)
{
	int ret;
	__le32 *tmp = kmalloc(sizeof(u32), GFP_KERNEL);

	if (!tmp)
		return -ENOMEM;
	*tmp = cpu_to_le32(val);
	wdev->hwbus_ops->lock(wdev->hwbus_priv);
	ret = indirect_write(wdev, reg, addr, tmp, sizeof(u32));
	_trace_io_ind_write32(reg, addr, val);
	wdev->hwbus_ops->unlock(wdev->hwbus_priv);
	kfree(tmp);
	return ret;
}

int wfx_data_read(struct wfx_dev *wdev, void *buf, size_t len)
{
	int ret;

	WARN((long)buf & 3, "%s: unaligned buffer", __func__);
	wdev->hwbus_ops->lock(wdev->hwbus_priv);
	ret = wdev->hwbus_ops->copy_from_io(wdev->hwbus_priv,
					    WFX_REG_IN_OUT_QUEUE, buf, len);
	_trace_io_read(WFX_REG_IN_OUT_QUEUE, buf, len);
	wdev->hwbus_ops->unlock(wdev->hwbus_priv);
	if (ret)
		dev_err(wdev->dev, "%s: bus communication error: %d\n",
			__func__, ret);
	return ret;
}

int wfx_data_write(struct wfx_dev *wdev, const void *buf, size_t len)
{
	int ret;

	WARN((long)buf & 3, "%s: unaligned buffer", __func__);
	wdev->hwbus_ops->lock(wdev->hwbus_priv);
	ret = wdev->hwbus_ops->copy_to_io(wdev->hwbus_priv,
					  WFX_REG_IN_OUT_QUEUE, buf, len);
	_trace_io_write(WFX_REG_IN_OUT_QUEUE, buf, len);
	wdev->hwbus_ops->unlock(wdev->hwbus_priv);
	if (ret)
		dev_err(wdev->dev, "%s: bus communication error: %d\n",
			__func__, ret);
	return ret;
}

int sram_buf_read(struct wfx_dev *wdev, u32 addr, void *buf, size_t len)
{
	return indirect_read_locked(wdev, WFX_REG_SRAM_DPORT, addr, buf, len);
}

int ahb_buf_read(struct wfx_dev *wdev, u32 addr, void *buf, size_t len)
{
	return indirect_read_locked(wdev, WFX_REG_AHB_DPORT, addr, buf, len);
}

int sram_buf_write(struct wfx_dev *wdev, u32 addr, const void *buf, size_t len)
{
	return indirect_write_locked(wdev, WFX_REG_SRAM_DPORT, addr, buf, len);
}

int ahb_buf_write(struct wfx_dev *wdev, u32 addr, const void *buf, size_t len)
{
	return indirect_write_locked(wdev, WFX_REG_AHB_DPORT, addr, buf, len);
}

int sram_reg_read(struct wfx_dev *wdev, u32 addr, u32 *val)
{
	return indirect_read32_locked(wdev, WFX_REG_SRAM_DPORT, addr, val);
}

int ahb_reg_read(struct wfx_dev *wdev, u32 addr, u32 *val)
{
	return indirect_read32_locked(wdev, WFX_REG_AHB_DPORT, addr, val);
}

int sram_reg_write(struct wfx_dev *wdev, u32 addr, u32 val)
{
	return indirect_write32_locked(wdev, WFX_REG_SRAM_DPORT, addr, val);
}

int ahb_reg_write(struct wfx_dev *wdev, u32 addr, u32 val)
{
	return indirect_write32_locked(wdev, WFX_REG_AHB_DPORT, addr, val);
}

int config_reg_read(struct wfx_dev *wdev, u32 *val)
{
	return read32_locked(wdev, WFX_REG_CONFIG, val);
}

int config_reg_write(struct wfx_dev *wdev, u32 val)
{
	return write32_locked(wdev, WFX_REG_CONFIG, val);
}

int config_reg_write_bits(struct wfx_dev *wdev, u32 mask, u32 val)
{
	return write32_bits_locked(wdev, WFX_REG_CONFIG, mask, val);
}

int control_reg_read(struct wfx_dev *wdev, u32 *val)
{
	return read32_locked(wdev, WFX_REG_CONTROL, val);
}

int control_reg_write(struct wfx_dev *wdev, u32 val)
{
	return write32_locked(wdev, WFX_REG_CONTROL, val);
}

int control_reg_write_bits(struct wfx_dev *wdev, u32 mask, u32 val)
{
	return write32_bits_locked(wdev, WFX_REG_CONTROL, mask, val);
}

int igpr_reg_read(struct wfx_dev *wdev, int index, u32 *val)
{
	int ret;

	*val = ~0; /* Never return undefined value */
	ret = write32_locked(wdev, WFX_REG_SET_GEN_R_W, IGPR_RW | index << 24);
	if (ret)
		return ret;
	ret = read32_locked(wdev, WFX_REG_SET_GEN_R_W, val);
	if (ret)
		return ret;
	*val &= IGPR_VALUE;
	return ret;
}

int igpr_reg_write(struct wfx_dev *wdev, int index, u32 val)
{
	return write32_locked(wdev, WFX_REG_SET_GEN_R_W, index << 24 | val);
}