drivers/hid/intel-thc-hid/intel-thc/intel-thc-dma.c

/* SPDX-License-Identifier: GPL-2.0 */
/* Copyright (c) 2024 Intel Corporation */

#include <linux/bitfield.h>
#include <linux/delay.h>
#include <linux/overflow.h>
#include <linux/regmap.h>
#include <linux/scatterlist.h>

#include "intel-thc-dev.h"
#include "intel-thc-dma.h"
#include "intel-thc-hw.h"

static void dma_set_prd_base_addr(struct thc_device *dev, u64 physical_addr,
				  struct thc_dma_configuration *dma_config)
{
	u32 addr_high, addr_low;

	if (!dma_config->is_enabled)
		return;

	addr_high = upper_32_bits(physical_addr);
	addr_low = lower_32_bits(physical_addr);

	regmap_write(dev->thc_regmap, dma_config->prd_base_addr_high, addr_high);
	regmap_write(dev->thc_regmap, dma_config->prd_base_addr_low, addr_low);
}

static void dma_set_start_bit(struct thc_device *dev,
			      struct thc_dma_configuration *dma_config)
{
	u32 ctrl, mask, mbits, data, offset;

	if (!dma_config->is_enabled)
		return;

	switch (dma_config->dma_channel) {
	case THC_RXDMA1:
	case THC_RXDMA2:
		if (dma_config->dma_channel == THC_RXDMA2) {
			mbits = FIELD_PREP(THC_M_PRT_DEVINT_CFG_1_THC_M_PRT_INTTYP_DATA_VAL,
					   THC_BITMASK_INTERRUPT_TYPE_DATA);
			mask = THC_M_PRT_DEVINT_CFG_1_THC_M_PRT_INTTYP_DATA_VAL;
			regmap_write_bits(dev->thc_regmap,
					  THC_M_PRT_DEVINT_CFG_1_OFFSET, mask, mbits);
		}

		mbits = THC_M_PRT_READ_DMA_CNTRL_IE_EOF |
			THC_M_PRT_READ_DMA_CNTRL_SOO |
			THC_M_PRT_READ_DMA_CNTRL_IE_STALL |
			THC_M_PRT_READ_DMA_CNTRL_IE_ERROR |
			THC_M_PRT_READ_DMA_CNTRL_START;

		mask = THC_M_PRT_READ_DMA_CNTRL_TPCWP | mbits;
		mask |= THC_M_PRT_READ_DMA_CNTRL_INT_SW_DMA_EN;
		ctrl = FIELD_PREP(THC_M_PRT_READ_DMA_CNTRL_TPCWP, THC_POINTER_WRAPAROUND) | mbits;
		offset = dma_config->dma_channel == THC_RXDMA1 ?
			 THC_M_PRT_READ_DMA_CNTRL_1_OFFSET : THC_M_PRT_READ_DMA_CNTRL_2_OFFSET;
		regmap_write_bits(dev->thc_regmap, offset, mask, ctrl);
		break;

	case THC_SWDMA:
		mbits = THC_M_PRT_READ_DMA_CNTRL_IE_DMACPL |
			THC_M_PRT_READ_DMA_CNTRL_IE_IOC |
			THC_M_PRT_READ_DMA_CNTRL_SOO |
			THC_M_PRT_READ_DMA_CNTRL_START;

		mask = THC_M_PRT_READ_DMA_CNTRL_TPCWP | mbits;
		ctrl = FIELD_PREP(THC_M_PRT_READ_DMA_CNTRL_TPCWP, THC_POINTER_WRAPAROUND) | mbits;
		regmap_write_bits(dev->thc_regmap, THC_M_PRT_READ_DMA_CNTRL_SW_OFFSET,
				  mask, ctrl);
		break;

	case THC_TXDMA:
		regmap_write_bits(dev->thc_regmap, THC_M_PRT_WRITE_INT_STS_OFFSET,
				  THC_M_PRT_WRITE_INT_STS_THC_WRDMA_CMPL_STATUS,
				  THC_M_PRT_WRITE_INT_STS_THC_WRDMA_CMPL_STATUS);

		/* Select interrupt or polling method upon Write completion */
		if (dev->dma_ctx->use_write_interrupts)
			data = THC_M_PRT_WRITE_DMA_CNTRL_THC_WRDMA_IE_IOC_DMACPL;
		else
			data = 0;

		data |= THC_M_PRT_WRITE_DMA_CNTRL_THC_WRDMA_START;
		mask = THC_M_PRT_WRITE_DMA_CNTRL_THC_WRDMA_IE_IOC_DMACPL |
		       THC_M_PRT_WRITE_DMA_CNTRL_THC_WRDMA_START;
		regmap_write_bits(dev->thc_regmap, THC_M_PRT_WRITE_DMA_CNTRL_OFFSET,
				  mask, data);
		break;

	default:
		break;
	}
}

static void dma_set_prd_control(struct thc_device *dev, u8 entry_count, u8 cb_depth,
				struct thc_dma_configuration *dma_config)
{
	u32 ctrl, mask;

	if (!dma_config->is_enabled)
		return;

	if (dma_config->dma_channel == THC_TXDMA) {
		mask = THC_M_PRT_WRITE_DMA_CNTRL_THC_WRDMA_PTEC;
		ctrl = FIELD_PREP(THC_M_PRT_WRITE_DMA_CNTRL_THC_WRDMA_PTEC, entry_count);
	} else {
		mask = THC_M_PRT_RPRD_CNTRL_PTEC | THC_M_PRT_RPRD_CNTRL_PCD;
		ctrl = FIELD_PREP(THC_M_PRT_RPRD_CNTRL_PTEC, entry_count) |
		       FIELD_PREP(THC_M_PRT_RPRD_CNTRL_PCD, cb_depth);
	}

	regmap_write_bits(dev->thc_regmap, dma_config->prd_cntrl, mask, ctrl);
}

static void dma_clear_prd_control(struct thc_device *dev,
				  struct thc_dma_configuration *dma_config)
{
	u32 mask;

	if (!dma_config->is_enabled)
		return;

	if (dma_config->dma_channel == THC_TXDMA)
		mask = THC_M_PRT_WRITE_DMA_CNTRL_THC_WRDMA_PTEC;
	else
		mask = THC_M_PRT_RPRD_CNTRL_PTEC | THC_M_PRT_RPRD_CNTRL_PCD;

	regmap_write_bits(dev->thc_regmap, dma_config->prd_cntrl, mask, 0);
}

static u8 dma_get_read_pointer(struct thc_device *dev,
			       struct thc_dma_configuration *dma_config)
{
	u32 ctrl, read_pointer;

	regmap_read(dev->thc_regmap, dma_config->dma_cntrl, &ctrl);
	read_pointer = FIELD_GET(THC_M_PRT_READ_DMA_CNTRL_TPCRP, ctrl);

	dev_dbg(dev->dev, "THC_M_PRT_READ_DMA_CNTRL 0x%x offset 0x%x TPCRP 0x%x\n",
		ctrl, dma_config->dma_cntrl, read_pointer);

	return read_pointer;
}

static u8 dma_get_write_pointer(struct thc_device *dev,
				struct thc_dma_configuration *dma_config)
{
	u32 ctrl, write_pointer;

	regmap_read(dev->thc_regmap, dma_config->dma_cntrl, &ctrl);
	write_pointer = FIELD_GET(THC_M_PRT_READ_DMA_CNTRL_TPCWP, ctrl);

	dev_dbg(dev->dev, "THC_M_PRT_READ_DMA_CNTRL 0x%x offset 0x%x TPCWP 0x%x\n",
		ctrl, dma_config->dma_cntrl, write_pointer);

	return write_pointer;
}

static void dma_set_write_pointer(struct thc_device *dev, u8 value,
				  struct thc_dma_configuration *dma_config)
{
	u32 ctrl, mask;

	mask = THC_M_PRT_READ_DMA_CNTRL_TPCWP;
	ctrl = FIELD_PREP(THC_M_PRT_READ_DMA_CNTRL_TPCWP, value);
	regmap_write_bits(dev->thc_regmap, dma_config->dma_cntrl, mask, ctrl);
}

static size_t dma_get_max_packet_size(struct thc_device *dev,
				      struct thc_dma_configuration *dma_config)
{
	return dma_config->max_packet_size;
}

static void dma_set_max_packet_size(struct thc_device *dev, size_t size,
				    struct thc_dma_configuration *dma_config)
{
	if (size) {
		dma_config->max_packet_size = ALIGN(size, SZ_4K);
		dma_config->is_enabled = true;
	}
}

static void thc_copy_one_sgl_to_prd(struct thc_device *dev,
				    struct thc_dma_configuration *config,
				    unsigned int ind)
{
	struct thc_prd_table *prd_tbl;
	struct scatterlist *sg;
	int j;

	prd_tbl = &config->prd_tbls[ind];

	for_each_sg(config->sgls[ind], sg, config->sgls_nent[ind], j) {
		prd_tbl->entries[j].dest_addr =
				sg_dma_address(sg) >> THC_ADDRESS_SHIFT;
		prd_tbl->entries[j].len = sg_dma_len(sg);
		prd_tbl->entries[j].hw_status = 0;
		prd_tbl->entries[j].end_of_prd = 0;
	}

	/* Set the end_of_prd flag in the last filled entry */
	if (j > 0)
		prd_tbl->entries[j - 1].end_of_prd = 1;
}

static void thc_copy_sgls_to_prd(struct thc_device *dev,
				 struct thc_dma_configuration *config)
{
	unsigned int i;

	memset(config->prd_tbls, 0, array_size(PRD_TABLE_SIZE, config->prd_tbl_num));

	for (i = 0; i < config->prd_tbl_num; i++)
		thc_copy_one_sgl_to_prd(dev, config, i);
}

static int setup_dma_buffers(struct thc_device *dev,
			     struct thc_dma_configuration *config,
			     enum dma_data_direction dir)
{
	size_t prd_tbls_size = array_size(PRD_TABLE_SIZE, config->prd_tbl_num);
	unsigned int i, nent = PRD_ENTRIES_NUM;
	dma_addr_t dma_handle;
	void *cpu_addr;
	size_t buf_sz;
	int count;

	if (!config->is_enabled)
		return 0;

	memset(config->sgls, 0, sizeof(config->sgls));
	memset(config->sgls_nent, 0, sizeof(config->sgls_nent));

	cpu_addr = dma_alloc_coherent(dev->dev, prd_tbls_size,
				      &dma_handle, GFP_KERNEL);
	if (!cpu_addr)
		return -ENOMEM;

	config->prd_tbls = cpu_addr;
	config->prd_tbls_dma_handle = dma_handle;

	buf_sz = dma_get_max_packet_size(dev, config);

	/* Allocate and map the scatter-gather lists, one for each PRD table */
	for (i = 0; i < config->prd_tbl_num; i++) {
		config->sgls[i] = sgl_alloc(buf_sz, GFP_KERNEL, &nent);
		if (!config->sgls[i] || nent > PRD_ENTRIES_NUM) {
			dev_err_once(dev->dev, "sgl_alloc (%uth) failed, nent %u\n",
				     i, nent);
			return -ENOMEM;
		}
		count = dma_map_sg(dev->dev, config->sgls[i], nent, dir);

		config->sgls_nent[i] = count;
	}

	thc_copy_sgls_to_prd(dev, config);

	return 0;
}

static void thc_reset_dma_settings(struct thc_device *dev)
{
	/* Stop all DMA channels and reset DMA read pointers */
	regmap_write_bits(dev->thc_regmap, THC_M_PRT_READ_DMA_CNTRL_1_OFFSET,
			  THC_M_PRT_READ_DMA_CNTRL_START, 0);
	regmap_write_bits(dev->thc_regmap, THC_M_PRT_READ_DMA_CNTRL_2_OFFSET,
			  THC_M_PRT_READ_DMA_CNTRL_START, 0);
	regmap_write_bits(dev->thc_regmap, THC_M_PRT_READ_DMA_CNTRL_SW_OFFSET,
			  THC_M_PRT_READ_DMA_CNTRL_START, 0);
	regmap_write_bits(dev->thc_regmap, THC_M_PRT_WRITE_DMA_CNTRL_OFFSET,
			  THC_M_PRT_WRITE_DMA_CNTRL_THC_WRDMA_START, 0);

	regmap_write_bits(dev->thc_regmap, THC_M_PRT_READ_DMA_CNTRL_1_OFFSET,
			  THC_M_PRT_READ_DMA_CNTRL_TPCPR,
			  THC_M_PRT_READ_DMA_CNTRL_TPCPR);
	regmap_write_bits(dev->thc_regmap, THC_M_PRT_READ_DMA_CNTRL_2_OFFSET,
			  THC_M_PRT_READ_DMA_CNTRL_TPCPR,
			  THC_M_PRT_READ_DMA_CNTRL_TPCPR);
	regmap_write_bits(dev->thc_regmap, THC_M_PRT_READ_DMA_CNTRL_SW_OFFSET,
			  THC_M_PRT_READ_DMA_CNTRL_TPCPR,
			  THC_M_PRT_READ_DMA_CNTRL_TPCPR);
}

static void release_dma_buffers(struct thc_device *dev,
				struct thc_dma_configuration *config)
{
	size_t prd_tbls_size = array_size(PRD_TABLE_SIZE, config->prd_tbl_num);
	unsigned int i;

	if (!config->is_enabled)
		return;

	for (i = 0; i < config->prd_tbl_num; i++) {
		if (!config->sgls[i] | !config->sgls_nent[i])
			continue;

		dma_unmap_sg(dev->dev, config->sgls[i],
			     config->sgls_nent[i],
			     config->dir);

		sgl_free(config->sgls[i]);
		config->sgls[i] = NULL;
	}

	memset(config->prd_tbls, 0, prd_tbls_size);

	if (config->prd_tbls) {
		dma_free_coherent(dev->dev, prd_tbls_size, config->prd_tbls,
				  config->prd_tbls_dma_handle);
		config->prd_tbls = NULL;
		config->prd_tbls_dma_handle = 0;
	}
}

struct thc_dma_context *thc_dma_init(struct thc_device *dev)
{
	struct thc_dma_context *dma_ctx;

	dma_ctx = devm_kzalloc(dev->dev, sizeof(*dma_ctx), GFP_KERNEL);
	if (!dma_ctx)
		return NULL;

	dev->dma_ctx = dma_ctx;

	dma_ctx->dma_config[THC_RXDMA1].dma_channel = THC_RXDMA1;
	dma_ctx->dma_config[THC_RXDMA2].dma_channel = THC_RXDMA2;
	dma_ctx->dma_config[THC_TXDMA].dma_channel = THC_TXDMA;
	dma_ctx->dma_config[THC_SWDMA].dma_channel = THC_SWDMA;

	dma_ctx->dma_config[THC_RXDMA1].dir = DMA_FROM_DEVICE;
	dma_ctx->dma_config[THC_RXDMA2].dir = DMA_FROM_DEVICE;
	dma_ctx->dma_config[THC_TXDMA].dir = DMA_TO_DEVICE;
	dma_ctx->dma_config[THC_SWDMA].dir = DMA_FROM_DEVICE;

	dma_ctx->dma_config[THC_RXDMA1].prd_tbl_num = PRD_TABLES_NUM;
	dma_ctx->dma_config[THC_RXDMA2].prd_tbl_num = PRD_TABLES_NUM;
	dma_ctx->dma_config[THC_TXDMA].prd_tbl_num = 1;
	dma_ctx->dma_config[THC_SWDMA].prd_tbl_num = 1;

	dma_ctx->dma_config[THC_RXDMA1].prd_base_addr_high = THC_M_PRT_RPRD_BA_HI_1_OFFSET;
	dma_ctx->dma_config[THC_RXDMA2].prd_base_addr_high = THC_M_PRT_RPRD_BA_HI_2_OFFSET;
	dma_ctx->dma_config[THC_TXDMA].prd_base_addr_high = THC_M_PRT_WPRD_BA_HI_OFFSET;
	dma_ctx->dma_config[THC_SWDMA].prd_base_addr_high = THC_M_PRT_RPRD_BA_HI_SW_OFFSET;

	dma_ctx->dma_config[THC_RXDMA1].prd_base_addr_low = THC_M_PRT_RPRD_BA_LOW_1_OFFSET;
	dma_ctx->dma_config[THC_RXDMA2].prd_base_addr_low = THC_M_PRT_RPRD_BA_LOW_2_OFFSET;
	dma_ctx->dma_config[THC_TXDMA].prd_base_addr_low = THC_M_PRT_WPRD_BA_LOW_OFFSET;
	dma_ctx->dma_config[THC_SWDMA].prd_base_addr_low = THC_M_PRT_RPRD_BA_LOW_SW_OFFSET;

	dma_ctx->dma_config[THC_RXDMA1].prd_cntrl = THC_M_PRT_RPRD_CNTRL_1_OFFSET;
	dma_ctx->dma_config[THC_RXDMA2].prd_cntrl = THC_M_PRT_RPRD_CNTRL_2_OFFSET;
	dma_ctx->dma_config[THC_TXDMA].prd_cntrl = THC_M_PRT_WRITE_DMA_CNTRL_OFFSET;
	dma_ctx->dma_config[THC_SWDMA].prd_cntrl = THC_M_PRT_RPRD_CNTRL_SW_OFFSET;

	dma_ctx->dma_config[THC_RXDMA1].dma_cntrl = THC_M_PRT_READ_DMA_CNTRL_1_OFFSET;
	dma_ctx->dma_config[THC_RXDMA2].dma_cntrl = THC_M_PRT_READ_DMA_CNTRL_2_OFFSET;
	dma_ctx->dma_config[THC_TXDMA].dma_cntrl = THC_M_PRT_WRITE_DMA_CNTRL_OFFSET;
	dma_ctx->dma_config[THC_SWDMA].dma_cntrl = THC_M_PRT_READ_DMA_CNTRL_SW_OFFSET;

	/* Enable write DMA completion interrupt by default */
	dma_ctx->use_write_interrupts = 1;

	return dma_ctx;
}

/**
 * thc_dma_set_max_packet_sizes - Set max packet sizes for all DMA engines
 *
 * @dev: The pointer of THC private device context
 * @mps_read1: RxDMA1 max packet size
 * @mps_read2: RxDMA2 max packet size
 * @mps_write: TxDMA max packet size
 * @mps_swdma: Software DMA max packet size
 *
 * If mps is not 0, it means the corresponding DMA channel is used, then set
 * the flag to turn on this channel.
 *
 * Return: 0 on success, other error codes on failed.
 */
int thc_dma_set_max_packet_sizes(struct thc_device *dev, size_t mps_read1,
				 size_t mps_read2, size_t mps_write,
				 size_t mps_swdma)
{
	if (!dev->dma_ctx) {
		dev_err_once(dev->dev,
			     "Cannot set max packet sizes because DMA context is NULL!\n");
		return -EINVAL;
	}

	dma_set_max_packet_size(dev, mps_read1, &dev->dma_ctx->dma_config[THC_RXDMA1]);
	dma_set_max_packet_size(dev, mps_read2, &dev->dma_ctx->dma_config[THC_RXDMA2]);
	dma_set_max_packet_size(dev, mps_write, &dev->dma_ctx->dma_config[THC_TXDMA]);
	dma_set_max_packet_size(dev, mps_swdma, &dev->dma_ctx->dma_config[THC_SWDMA]);

	return 0;
}
EXPORT_SYMBOL_NS_GPL(thc_dma_set_max_packet_sizes, "INTEL_THC");

/**
 * thc_dma_allocate - Allocate DMA buffers for all DMA engines
 *
 * @dev: The pointer of THC private device context
 *
 * Return: 0 on success, other error codes on failed.
 */
int thc_dma_allocate(struct thc_device *dev)
{
	int ret, chan;

	for (chan = 0; chan < MAX_THC_DMA_CHANNEL; chan++) {
		ret = setup_dma_buffers(dev, &dev->dma_ctx->dma_config[chan],
					dev->dma_ctx->dma_config[chan].dir);
		if (ret < 0) {
			dev_err_once(dev->dev, "DMA setup failed for DMA channel %d\n", chan);
			goto release_bufs;
		}
	}

	return 0;

release_bufs:
	while (chan--)
		release_dma_buffers(dev, &dev->dma_ctx->dma_config[chan]);

	return ret;
}
EXPORT_SYMBOL_NS_GPL(thc_dma_allocate, "INTEL_THC");

/**
 * thc_dma_release - Release DMA buffers for all DMA engines
 *
 * @dev: The pointer of THC private device context
 */
void thc_dma_release(struct thc_device *dev)
{
	int chan;

	for (chan = 0; chan < MAX_THC_DMA_CHANNEL; chan++)
		release_dma_buffers(dev, &dev->dma_ctx->dma_config[chan]);
}
EXPORT_SYMBOL_NS_GPL(thc_dma_release, "INTEL_THC");

static int calc_prd_entries_num(struct thc_prd_table *prd_tbl,
				size_t mes_len, u8 *nent)
{
	*nent = DIV_ROUND_UP(mes_len, THC_MIN_BYTES_PER_SG_LIST_ENTRY);
	if (*nent > PRD_ENTRIES_NUM)
		return -EMSGSIZE;

	return 0;
}

static size_t calc_message_len(struct thc_prd_table *prd_tbl, u8 *nent)
{
	size_t mes_len = 0;
	unsigned int j;

	for (j = 0; j < PRD_ENTRIES_NUM; j++) {
		mes_len += prd_tbl->entries[j].len;
		if (prd_tbl->entries[j].end_of_prd)
			break;
	}

	*nent = j + 1;

	return mes_len;
}

/**
 * thc_dma_configure - Configure DMA settings for all DMA engines
 *
 * @dev: The pointer of THC private device context
 *
 * Return: 0 on success, other error codes on failed.
 */
int thc_dma_configure(struct thc_device *dev)
{
	struct thc_dma_context *dma_ctx = dev->dma_ctx;
	int chan;

	thc_reset_dma_settings(dev);

	if (!dma_ctx) {
		dev_err_once(dev->dev, "Cannot do DMA configure because DMA context is NULL\n");
		return -EINVAL;
	}

	for (chan = 0; chan < MAX_THC_DMA_CHANNEL; chan++) {
		dma_set_prd_base_addr(dev,
				      dma_ctx->dma_config[chan].prd_tbls_dma_handle,
				      &dma_ctx->dma_config[chan]);

		dma_set_prd_control(dev, PRD_ENTRIES_NUM - 1,
				    dma_ctx->dma_config[chan].prd_tbl_num - 1,
				    &dma_ctx->dma_config[chan]);
	}

	/* Start read2 DMA engine */
	dma_set_start_bit(dev, &dma_ctx->dma_config[THC_RXDMA2]);

	dev_dbg(dev->dev, "DMA configured successfully!\n");

	return 0;
}
EXPORT_SYMBOL_NS_GPL(thc_dma_configure, "INTEL_THC");

/**
 * thc_dma_unconfigure - Unconfigure DMA settings for all DMA engines
 *
 * @dev: The pointer of THC private device context
 */
void thc_dma_unconfigure(struct thc_device *dev)
{
	int chan;

	for (chan = 0; chan < MAX_THC_DMA_CHANNEL; chan++) {
		dma_set_prd_base_addr(dev, 0, &dev->dma_ctx->dma_config[chan]);
		dma_clear_prd_control(dev, &dev->dma_ctx->dma_config[chan]);
	}

	regmap_write_bits(dev->thc_regmap, THC_M_PRT_READ_DMA_CNTRL_1_OFFSET,
			  THC_M_PRT_READ_DMA_CNTRL_START, 0);

	regmap_write_bits(dev->thc_regmap, THC_M_PRT_READ_DMA_CNTRL_2_OFFSET,
			  THC_M_PRT_READ_DMA_CNTRL_START, 0);
}
EXPORT_SYMBOL_NS_GPL(thc_dma_unconfigure, "INTEL_THC");

static int thc_wait_for_dma_pause(struct thc_device *dev, enum thc_dma_channel channel)
{
	u32 ctrl_reg, sts_reg, sts;
	int ret;

	ctrl_reg = (channel == THC_RXDMA1) ? THC_M_PRT_READ_DMA_CNTRL_1_OFFSET :
			((channel == THC_RXDMA2) ? THC_M_PRT_READ_DMA_CNTRL_2_OFFSET :
						   THC_M_PRT_READ_DMA_CNTRL_SW_OFFSET);

	regmap_write_bits(dev->thc_regmap, ctrl_reg, THC_M_PRT_READ_DMA_CNTRL_START, 0);

	sts_reg = (channel == THC_RXDMA1) ? THC_M_PRT_READ_DMA_INT_STS_1_OFFSET :
			((channel == THC_RXDMA2) ? THC_M_PRT_READ_DMA_INT_STS_2_OFFSET :
						   THC_M_PRT_READ_DMA_INT_STS_SW_OFFSET);

	ret = regmap_read_poll_timeout(dev->thc_regmap, sts_reg, sts,
				       !(sts & THC_M_PRT_READ_DMA_INT_STS_ACTIVE),
				       THC_DEFAULT_RXDMA_POLLING_US_INTERVAL,
				       THC_DEFAULT_RXDMA_POLLING_US_TIMEOUT);

	if (ret) {
		dev_err_once(dev->dev,
			     "Timeout while waiting for DMA %d stop\n", channel);
		return ret;
	}

	return 0;
}

static int read_dma_buffer(struct thc_device *dev,
			   struct thc_dma_configuration *read_config,
			   u8 prd_table_index, void *read_buff)
{
	struct thc_prd_table *prd_tbl;
	struct scatterlist *sg;
	size_t mes_len, ret;
	u8 nent;

	if (prd_table_index >= read_config->prd_tbl_num) {
		dev_err_once(dev->dev, "PRD table index %d too big\n", prd_table_index);
		return -EINVAL;
	}

	prd_tbl = &read_config->prd_tbls[prd_table_index];
	mes_len = calc_message_len(prd_tbl, &nent);
	if (mes_len > read_config->max_packet_size) {
		dev_err(dev->dev,
			"Message length %zu is bigger than buffer length %lu\n",
			mes_len, read_config->max_packet_size);
		return -EMSGSIZE;
	}

	sg = read_config->sgls[prd_table_index];
	ret = sg_copy_to_buffer(sg, nent, read_buff, mes_len);
	if (ret != mes_len) {
		dev_err_once(dev->dev, "Copied %zu bytes instead of requested %zu\n",
			     ret, mes_len);
		return -EIO;
	}

	return mes_len;
}

static void update_write_pointer(struct thc_device *dev,
				 struct thc_dma_configuration *read_config)
{
	u8 write_ptr = dma_get_write_pointer(dev, read_config);

	if (write_ptr + 1 == THC_WRAPAROUND_VALUE_ODD)
		dma_set_write_pointer(dev, THC_POINTER_WRAPAROUND, read_config);
	else if (write_ptr + 1 == THC_WRAPAROUND_VALUE_EVEN)
		dma_set_write_pointer(dev, 0, read_config);
	else
		dma_set_write_pointer(dev, write_ptr + 1, read_config);
}

static int is_dma_buf_empty(struct thc_device *dev,
			    struct thc_dma_configuration *read_config,
			    u8 *read_ptr, u8 *write_ptr)
{
	*read_ptr = dma_get_read_pointer(dev, read_config);
	*write_ptr = dma_get_write_pointer(dev, read_config);

	if ((*read_ptr & THC_POINTER_MASK) == (*write_ptr & THC_POINTER_MASK))
		if (*read_ptr != *write_ptr)
			return true;

	return false;
}

static int thc_dma_read(struct thc_device *dev,
			struct thc_dma_configuration *read_config,
			void *read_buff, size_t *read_len, int *read_finished)
{
	u8 read_ptr, write_ptr, prd_table_index;
	int status;

	if (!is_dma_buf_empty(dev, read_config, &read_ptr, &write_ptr)) {
		prd_table_index = write_ptr & THC_POINTER_MASK;

		status = read_dma_buffer(dev, read_config, prd_table_index, read_buff);
		if (status <= 0) {
			dev_err_once(dev->dev, "read DMA buffer failed %d\n", status);
			return -EIO;
		}

		*read_len = status;

		/* Clear the relevant PRD table */
		thc_copy_one_sgl_to_prd(dev, read_config, prd_table_index);

		/* Increment the write pointer to let the HW know we have processed this PRD */
		update_write_pointer(dev, read_config);
	}

	/*
	 * This function only reads one frame from PRD table for each call, so we need to
	 * check if all DMAed data is read out and return the flag to the caller. Caller
	 * should repeatedly call thc_dma_read() until all DMAed data is handled.
	 */
	if (read_finished)
		*read_finished = is_dma_buf_empty(dev, read_config, &read_ptr, &write_ptr) ? 1 : 0;

	return 0;
}

/**
 * thc_rxdma_read - Read data from RXDMA buffer
 *
 * @dev: The pointer of THC private device context
 * @dma_channel: The RXDMA engine of read data source
 * @read_buff: The pointer of the read data buffer
 * @read_len: The pointer of the read data length
 * @read_finished: The pointer of the flag indicating if all pending data has been read out
 *
 * Return: 0 on success, other error codes on failed.
 */
int thc_rxdma_read(struct thc_device *dev, enum thc_dma_channel dma_channel,
		   void *read_buff, size_t *read_len, int *read_finished)
{
	struct thc_dma_configuration *dma_config;
	int ret;

	dma_config = &dev->dma_ctx->dma_config[dma_channel];

	if (!dma_config->is_enabled) {
		dev_err_once(dev->dev, "The DMA channel %d is not enabled", dma_channel);
		return -EINVAL;
	}

	if (!read_buff || !read_len) {
		dev_err(dev->dev, "Invalid input parameters, read_buff %p, read_len %p\n",
			read_buff, read_len);
		return -EINVAL;
	}

	if (dma_channel >= THC_TXDMA) {
		dev_err(dev->dev, "Unsupported DMA channel for RxDMA read, %d\n", dma_channel);
		return -EINVAL;
	}

	ret = thc_dma_read(dev, dma_config, read_buff, read_len, read_finished);

	return ret;
}
EXPORT_SYMBOL_NS_GPL(thc_rxdma_read, "INTEL_THC");

static int thc_swdma_read_start(struct thc_device *dev, void *write_buff,
				size_t write_len, u32 *prd_tbl_len)
{
	u32 mask, val, data0 = 0, data1 = 0;
	int ret;

	ret = thc_interrupt_quiesce(dev, true);
	if (ret)
		return ret;

	if (thc_wait_for_dma_pause(dev, THC_RXDMA1) || thc_wait_for_dma_pause(dev, THC_RXDMA2))
		return -EIO;

	thc_reset_dma_settings(dev);

	mask = THC_M_PRT_RPRD_CNTRL_SW_THC_SWDMA_I2C_WBC |
	       THC_M_PRT_RPRD_CNTRL_SW_THC_SWDMA_I2C_RX_DLEN_EN;
	val = FIELD_PREP(THC_M_PRT_RPRD_CNTRL_SW_THC_SWDMA_I2C_WBC, write_len) |
	      ((!prd_tbl_len) ? THC_M_PRT_RPRD_CNTRL_SW_THC_SWDMA_I2C_RX_DLEN_EN : 0);
	regmap_write_bits(dev->thc_regmap, THC_M_PRT_RPRD_CNTRL_SW_OFFSET,
			  mask, val);

	if (prd_tbl_len) {
		mask = THC_M_PRT_SW_DMA_PRD_TABLE_LEN_THC_M_PRT_SW_DMA_PRD_TABLE_LEN;
		val = FIELD_PREP(THC_M_PRT_SW_DMA_PRD_TABLE_LEN_THC_M_PRT_SW_DMA_PRD_TABLE_LEN,
				 *prd_tbl_len);
		regmap_write_bits(dev->thc_regmap, THC_M_PRT_SW_DMA_PRD_TABLE_LEN_OFFSET,
				  mask, val);
	}

	if (write_len <= sizeof(u32)) {
		for (int i = 0; i < write_len; i++)
			data0 |= *(((u8 *)write_buff) + i) << (i * 8);

		regmap_write(dev->thc_regmap, THC_M_PRT_SW_SEQ_DATA0_ADDR_OFFSET, data0);
	} else if (write_len <= 2 * sizeof(u32)) {
		data0 = *(u32 *)write_buff;
		regmap_write(dev->thc_regmap, THC_M_PRT_SW_SEQ_DATA0_ADDR_OFFSET, data0);

		for (int i = 0; i < write_len - sizeof(u32); i++)
			data1 |= *(((u8 *)write_buff) + sizeof(u32) + i) << (i * 8);

		regmap_write(dev->thc_regmap, THC_M_PRT_SW_SEQ_DATA1_OFFSET, data1);
	}
	dma_set_start_bit(dev, &dev->dma_ctx->dma_config[THC_SWDMA]);

	return 0;
}

static int thc_swdma_read_completion(struct thc_device *dev)
{
	int ret;

	ret = thc_wait_for_dma_pause(dev, THC_SWDMA);
	if (ret)
		return ret;

	thc_reset_dma_settings(dev);

	dma_set_start_bit(dev, &dev->dma_ctx->dma_config[THC_RXDMA2]);

	ret = thc_interrupt_quiesce(dev, false);

	return ret;
}

/**
 * thc_swdma_read - Use software DMA to read data from touch device
 *
 * @dev: The pointer of THC private device context
 * @write_buff: The pointer of write buffer for SWDMA sequence
 * @write_len: The write data length for SWDMA sequence
 * @prd_tbl_len: The prd table length of SWDMA engine, can be set to NULL
 * @read_buff: The pointer of the read data buffer
 * @read_len: The pointer of the read data length
 *
 * Return: 0 on success, other error codes on failed.
 */
int thc_swdma_read(struct thc_device *dev, void *write_buff, size_t write_len,
		   u32 *prd_tbl_len, void *read_buff, size_t *read_len)
{
	int ret;

	if (!(&dev->dma_ctx->dma_config[THC_SWDMA])->is_enabled) {
		dev_err_once(dev->dev, "The SWDMA channel is not enabled");
		return -EINVAL;
	}

	if (!read_buff || !read_len) {
		dev_err(dev->dev, "Invalid input parameters, read_buff %p, read_len %p\n",
			read_buff, read_len);
		return -EINVAL;
	}

	if (mutex_lock_interruptible(&dev->thc_bus_lock))
		return -EINTR;

	dev->swdma_done = false;

	ret = thc_swdma_read_start(dev, write_buff, write_len, prd_tbl_len);
	if (ret)
		goto end;

	ret = wait_event_interruptible_timeout(dev->swdma_complete_wait, dev->swdma_done, 1 * HZ);
	if (ret <= 0 || !dev->swdma_done) {
		dev_err_once(dev->dev, "timeout for waiting SWDMA completion\n");
		ret = -ETIMEDOUT;
		goto end;
	}

	ret = thc_dma_read(dev, &dev->dma_ctx->dma_config[THC_SWDMA], read_buff, read_len, NULL);
	if (ret)
		goto end;

	ret = thc_swdma_read_completion(dev);

end:
	mutex_unlock(&dev->thc_bus_lock);
	return ret;
}
EXPORT_SYMBOL_NS_GPL(thc_swdma_read, "INTEL_THC");

static int write_dma_buffer(struct thc_device *dev,
			    void *buffer, size_t buf_len)
{
	struct thc_dma_configuration *write_config = &dev->dma_ctx->dma_config[THC_TXDMA];
	struct thc_prd_table *prd_tbl;
	struct scatterlist *sg;
	unsigned long len_left;
	size_t ret;
	u8 nent;
	int i;

	/* There is only one PRD table for write */
	prd_tbl = &write_config->prd_tbls[0];

	if (calc_prd_entries_num(prd_tbl, buf_len, &nent) < 0) {
		dev_err(dev->dev, "Tx message length too big (%zu)\n", buf_len);
		return -EOVERFLOW;
	}

	sg = write_config->sgls[0];
	ret = sg_copy_from_buffer(sg, nent, buffer, buf_len);
	if (ret != buf_len) {
		dev_err_once(dev->dev, "Copied %zu bytes instead of requested %zu\n",
			     ret, buf_len);
		return -EIO;
	}

	prd_tbl = &write_config->prd_tbls[0];
	len_left = buf_len;

	for_each_sg(write_config->sgls[0], sg, write_config->sgls_nent[0], i) {
		if (sg_dma_address(sg) == 0 || sg_dma_len(sg) == 0) {
			dev_err_once(dev->dev, "SGList: zero address or length\n");
			return -EINVAL;
		}

		prd_tbl->entries[i].dest_addr =
				sg_dma_address(sg) >> THC_ADDRESS_SHIFT;

		if (len_left < sg_dma_len(sg)) {
			prd_tbl->entries[i].len = len_left;
			prd_tbl->entries[i].end_of_prd = 1;
			break;
		}

		prd_tbl->entries[i].len = sg_dma_len(sg);
		prd_tbl->entries[i].end_of_prd = 0;

		len_left -= sg_dma_len(sg);
	}

	dma_set_prd_control(dev, i, 0, write_config);

	return 0;
}

static void thc_ensure_performance_limitations(struct thc_device *dev)
{
	unsigned long delay_usec = 0;
	/*
	 * Minimum amount of delay the THC / QUICKSPI driver must wait
	 * between end of write operation and begin of read operation.
	 * This value shall be in 10us multiples.
	 */
	if (dev->perf_limit > 0) {
		delay_usec = dev->perf_limit * 10;
		udelay(delay_usec);
	}
}

static void thc_dma_write_completion(struct thc_device *dev)
{
	thc_ensure_performance_limitations(dev);
}

/**
 * thc_dma_write - Use TXDMA to write data to touch device
 *
 * @dev: The pointer of THC private device context
 * @buffer: The pointer of write data buffer
 * @buf_len: The write data length
 *
 * Return: 0 on success, other error codes on failed.
 */
int thc_dma_write(struct thc_device *dev, void *buffer, size_t buf_len)
{
	bool restore_interrupts = false;
	u32 sts, ctrl;
	int ret;

	if (!(&dev->dma_ctx->dma_config[THC_TXDMA])->is_enabled) {
		dev_err_once(dev->dev, "The TxDMA channel is not enabled\n");
		return -EINVAL;
	}

	if (!buffer || buf_len <= 0) {
		dev_err(dev->dev, "Invalid input parameters, buffer %p\n, buf_len %zu\n",
			buffer, buf_len);
		return -EINVAL;
	}

	regmap_read(dev->thc_regmap, THC_M_PRT_WRITE_INT_STS_OFFSET, &sts);
	if (sts & THC_M_PRT_WRITE_INT_STS_THC_WRDMA_ACTIVE) {
		dev_err_once(dev->dev, "THC TxDMA is till active and can't start again\n");
		return -EBUSY;
	}

	if (mutex_lock_interruptible(&dev->thc_bus_lock))
		return -EINTR;

	regmap_read(dev->thc_regmap, THC_M_PRT_CONTROL_OFFSET, &ctrl);

	ret = write_dma_buffer(dev, buffer, buf_len);
	if (ret)
		goto end;

	if (dev->perf_limit && !(ctrl & THC_M_PRT_CONTROL_THC_DEVINT_QUIESCE_HW_STS)) {
		ret = thc_interrupt_quiesce(dev, true);
		if (ret)
			goto end;

		restore_interrupts = true;
	}

	dev->write_done = false;

	dma_set_start_bit(dev, &dev->dma_ctx->dma_config[THC_TXDMA]);

	ret = wait_event_interruptible_timeout(dev->write_complete_wait, dev->write_done, 1 * HZ);
	if (ret <= 0 || !dev->write_done) {
		dev_err_once(dev->dev, "timeout for waiting TxDMA completion\n");
		ret = -ETIMEDOUT;
		goto end;
	}

	thc_dma_write_completion(dev);
	mutex_unlock(&dev->thc_bus_lock);
	return 0;

end:
	mutex_unlock(&dev->thc_bus_lock);

	if (restore_interrupts)
		ret = thc_interrupt_quiesce(dev, false);

	return ret;
}
EXPORT_SYMBOL_NS_GPL(thc_dma_write, "INTEL_THC");