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   1/*
   2 * Copyright (c) 2016, The Linux Foundation. All rights reserved.
   3 *
   4 * This software is licensed under the terms of the GNU General Public
   5 * License version 2, as published by the Free Software Foundation, and
   6 * may be copied, distributed, and modified under those terms.
   7 *
   8 * This program is distributed in the hope that it will be useful,
   9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11 * GNU General Public License for more details.
  12 */
  13
  14#include <linux/clk.h>
  15#include <linux/slab.h>
  16#include <linux/bitops.h>
  17#include <linux/dma-mapping.h>
  18#include <linux/dmaengine.h>
  19#include <linux/module.h>
  20#include <linux/mtd/nand.h>
  21#include <linux/mtd/partitions.h>
  22#include <linux/of.h>
  23#include <linux/of_device.h>
  24#include <linux/delay.h>
  25
  26/* NANDc reg offsets */
  27#define	NAND_FLASH_CMD			0x00
  28#define	NAND_ADDR0			0x04
  29#define	NAND_ADDR1			0x08
  30#define	NAND_FLASH_CHIP_SELECT		0x0c
  31#define	NAND_EXEC_CMD			0x10
  32#define	NAND_FLASH_STATUS		0x14
  33#define	NAND_BUFFER_STATUS		0x18
  34#define	NAND_DEV0_CFG0			0x20
  35#define	NAND_DEV0_CFG1			0x24
  36#define	NAND_DEV0_ECC_CFG		0x28
  37#define	NAND_DEV1_ECC_CFG		0x2c
  38#define	NAND_DEV1_CFG0			0x30
  39#define	NAND_DEV1_CFG1			0x34
  40#define	NAND_READ_ID			0x40
  41#define	NAND_READ_STATUS		0x44
  42#define	NAND_DEV_CMD0			0xa0
  43#define	NAND_DEV_CMD1			0xa4
  44#define	NAND_DEV_CMD2			0xa8
  45#define	NAND_DEV_CMD_VLD		0xac
  46#define	SFLASHC_BURST_CFG		0xe0
  47#define	NAND_ERASED_CW_DETECT_CFG	0xe8
  48#define	NAND_ERASED_CW_DETECT_STATUS	0xec
  49#define	NAND_EBI2_ECC_BUF_CFG		0xf0
  50#define	FLASH_BUF_ACC			0x100
  51
  52#define	NAND_CTRL			0xf00
  53#define	NAND_VERSION			0xf08
  54#define	NAND_READ_LOCATION_0		0xf20
  55#define	NAND_READ_LOCATION_1		0xf24
  56
  57/* dummy register offsets, used by write_reg_dma */
  58#define	NAND_DEV_CMD1_RESTORE		0xdead
  59#define	NAND_DEV_CMD_VLD_RESTORE	0xbeef
  60
  61/* NAND_FLASH_CMD bits */
  62#define	PAGE_ACC			BIT(4)
  63#define	LAST_PAGE			BIT(5)
  64
  65/* NAND_FLASH_CHIP_SELECT bits */
  66#define	NAND_DEV_SEL			0
  67#define	DM_EN				BIT(2)
  68
  69/* NAND_FLASH_STATUS bits */
  70#define	FS_OP_ERR			BIT(4)
  71#define	FS_READY_BSY_N			BIT(5)
  72#define	FS_MPU_ERR			BIT(8)
  73#define	FS_DEVICE_STS_ERR		BIT(16)
  74#define	FS_DEVICE_WP			BIT(23)
  75
  76/* NAND_BUFFER_STATUS bits */
  77#define	BS_UNCORRECTABLE_BIT		BIT(8)
  78#define	BS_CORRECTABLE_ERR_MSK		0x1f
  79
  80/* NAND_DEVn_CFG0 bits */
  81#define	DISABLE_STATUS_AFTER_WRITE	4
  82#define	CW_PER_PAGE			6
  83#define	UD_SIZE_BYTES			9
  84#define	ECC_PARITY_SIZE_BYTES_RS	19
  85#define	SPARE_SIZE_BYTES		23
  86#define	NUM_ADDR_CYCLES			27
  87#define	STATUS_BFR_READ			30
  88#define	SET_RD_MODE_AFTER_STATUS	31
  89
  90/* NAND_DEVn_CFG0 bits */
  91#define	DEV0_CFG1_ECC_DISABLE		0
  92#define	WIDE_FLASH			1
  93#define	NAND_RECOVERY_CYCLES		2
  94#define	CS_ACTIVE_BSY			5
  95#define	BAD_BLOCK_BYTE_NUM		6
  96#define	BAD_BLOCK_IN_SPARE_AREA		16
  97#define	WR_RD_BSY_GAP			17
  98#define	ENABLE_BCH_ECC			27
  99
 100/* NAND_DEV0_ECC_CFG bits */
 101#define	ECC_CFG_ECC_DISABLE		0
 102#define	ECC_SW_RESET			1
 103#define	ECC_MODE			4
 104#define	ECC_PARITY_SIZE_BYTES_BCH	8
 105#define	ECC_NUM_DATA_BYTES		16
 106#define	ECC_FORCE_CLK_OPEN		30
 107
 108/* NAND_DEV_CMD1 bits */
 109#define	READ_ADDR			0
 110
 111/* NAND_DEV_CMD_VLD bits */
 112#define	READ_START_VLD			0
 113
 114/* NAND_EBI2_ECC_BUF_CFG bits */
 115#define	NUM_STEPS			0
 116
 117/* NAND_ERASED_CW_DETECT_CFG bits */
 118#define	ERASED_CW_ECC_MASK		1
 119#define	AUTO_DETECT_RES			0
 120#define	MASK_ECC			(1 << ERASED_CW_ECC_MASK)
 121#define	RESET_ERASED_DET		(1 << AUTO_DETECT_RES)
 122#define	ACTIVE_ERASED_DET		(0 << AUTO_DETECT_RES)
 123#define	CLR_ERASED_PAGE_DET		(RESET_ERASED_DET | MASK_ECC)
 124#define	SET_ERASED_PAGE_DET		(ACTIVE_ERASED_DET | MASK_ECC)
 125
 126/* NAND_ERASED_CW_DETECT_STATUS bits */
 127#define	PAGE_ALL_ERASED			BIT(7)
 128#define	CODEWORD_ALL_ERASED		BIT(6)
 129#define	PAGE_ERASED			BIT(5)
 130#define	CODEWORD_ERASED			BIT(4)
 131#define	ERASED_PAGE			(PAGE_ALL_ERASED | PAGE_ERASED)
 132#define	ERASED_CW			(CODEWORD_ALL_ERASED | CODEWORD_ERASED)
 133
 134/* Version Mask */
 135#define	NAND_VERSION_MAJOR_MASK		0xf0000000
 136#define	NAND_VERSION_MAJOR_SHIFT	28
 137#define	NAND_VERSION_MINOR_MASK		0x0fff0000
 138#define	NAND_VERSION_MINOR_SHIFT	16
 139
 140/* NAND OP_CMDs */
 141#define	PAGE_READ			0x2
 142#define	PAGE_READ_WITH_ECC		0x3
 143#define	PAGE_READ_WITH_ECC_SPARE	0x4
 144#define	PROGRAM_PAGE			0x6
 145#define	PAGE_PROGRAM_WITH_ECC		0x7
 146#define	PROGRAM_PAGE_SPARE		0x9
 147#define	BLOCK_ERASE			0xa
 148#define	FETCH_ID			0xb
 149#define	RESET_DEVICE			0xd
 150
 151/*
 152 * the NAND controller performs reads/writes with ECC in 516 byte chunks.
 153 * the driver calls the chunks 'step' or 'codeword' interchangeably
 154 */
 155#define	NANDC_STEP_SIZE			512
 156
 157/*
 158 * the largest page size we support is 8K, this will have 16 steps/codewords
 159 * of 512 bytes each
 160 */
 161#define	MAX_NUM_STEPS			(SZ_8K / NANDC_STEP_SIZE)
 162
 163/* we read at most 3 registers per codeword scan */
 164#define	MAX_REG_RD			(3 * MAX_NUM_STEPS)
 165
 166/* ECC modes supported by the controller */
 167#define	ECC_NONE	BIT(0)
 168#define	ECC_RS_4BIT	BIT(1)
 169#define	ECC_BCH_4BIT	BIT(2)
 170#define	ECC_BCH_8BIT	BIT(3)
 171
 172struct desc_info {
 173	struct list_head node;
 174
 175	enum dma_data_direction dir;
 176	struct scatterlist sgl;
 177	struct dma_async_tx_descriptor *dma_desc;
 178};
 179
 180/*
 181 * holds the current register values that we want to write. acts as a contiguous
 182 * chunk of memory which we use to write the controller registers through DMA.
 183 */
 184struct nandc_regs {
 185	__le32 cmd;
 186	__le32 addr0;
 187	__le32 addr1;
 188	__le32 chip_sel;
 189	__le32 exec;
 190
 191	__le32 cfg0;
 192	__le32 cfg1;
 193	__le32 ecc_bch_cfg;
 194
 195	__le32 clrflashstatus;
 196	__le32 clrreadstatus;
 197
 198	__le32 cmd1;
 199	__le32 vld;
 200
 201	__le32 orig_cmd1;
 202	__le32 orig_vld;
 203
 204	__le32 ecc_buf_cfg;
 205};
 206
 207/*
 208 * NAND controller data struct
 209 *
 210 * @controller:			base controller structure
 211 * @host_list:			list containing all the chips attached to the
 212 *				controller
 213 * @dev:			parent device
 214 * @base:			MMIO base
 215 * @base_dma:			physical base address of controller registers
 216 * @core_clk:			controller clock
 217 * @aon_clk:			another controller clock
 218 *
 219 * @chan:			dma channel
 220 * @cmd_crci:			ADM DMA CRCI for command flow control
 221 * @data_crci:			ADM DMA CRCI for data flow control
 222 * @desc_list:			DMA descriptor list (list of desc_infos)
 223 *
 224 * @data_buffer:		our local DMA buffer for page read/writes,
 225 *				used when we can't use the buffer provided
 226 *				by upper layers directly
 227 * @buf_size/count/start:	markers for chip->read_buf/write_buf functions
 228 * @reg_read_buf:		local buffer for reading back registers via DMA
 229 * @reg_read_pos:		marker for data read in reg_read_buf
 230 *
 231 * @regs:			a contiguous chunk of memory for DMA register
 232 *				writes. contains the register values to be
 233 *				written to controller
 234 * @cmd1/vld:			some fixed controller register values
 235 * @ecc_modes:			supported ECC modes by the current controller,
 236 *				initialized via DT match data
 237 */
 238struct qcom_nand_controller {
 239	struct nand_hw_control controller;
 240	struct list_head host_list;
 241
 242	struct device *dev;
 243
 244	void __iomem *base;
 245	dma_addr_t base_dma;
 246
 247	struct clk *core_clk;
 248	struct clk *aon_clk;
 249
 250	struct dma_chan *chan;
 251	unsigned int cmd_crci;
 252	unsigned int data_crci;
 253	struct list_head desc_list;
 254
 255	u8		*data_buffer;
 256	int		buf_size;
 257	int		buf_count;
 258	int		buf_start;
 259
 260	__le32 *reg_read_buf;
 261	int reg_read_pos;
 262
 263	struct nandc_regs *regs;
 264
 265	u32 cmd1, vld;
 266	u32 ecc_modes;
 267};
 268
 269/*
 270 * NAND chip structure
 271 *
 272 * @chip:			base NAND chip structure
 273 * @node:			list node to add itself to host_list in
 274 *				qcom_nand_controller
 275 *
 276 * @cs:				chip select value for this chip
 277 * @cw_size:			the number of bytes in a single step/codeword
 278 *				of a page, consisting of all data, ecc, spare
 279 *				and reserved bytes
 280 * @cw_data:			the number of bytes within a codeword protected
 281 *				by ECC
 282 * @use_ecc:			request the controller to use ECC for the
 283 *				upcoming read/write
 284 * @bch_enabled:		flag to tell whether BCH ECC mode is used
 285 * @ecc_bytes_hw:		ECC bytes used by controller hardware for this
 286 *				chip
 287 * @status:			value to be returned if NAND_CMD_STATUS command
 288 *				is executed
 289 * @last_command:		keeps track of last command on this chip. used
 290 *				for reading correct status
 291 *
 292 * @cfg0, cfg1, cfg0_raw..:	NANDc register configurations needed for
 293 *				ecc/non-ecc mode for the current nand flash
 294 *				device
 295 */
 296struct qcom_nand_host {
 297	struct nand_chip chip;
 298	struct list_head node;
 299
 300	int cs;
 301	int cw_size;
 302	int cw_data;
 303	bool use_ecc;
 304	bool bch_enabled;
 305	int ecc_bytes_hw;
 306	int spare_bytes;
 307	int bbm_size;
 308	u8 status;
 309	int last_command;
 310
 311	u32 cfg0, cfg1;
 312	u32 cfg0_raw, cfg1_raw;
 313	u32 ecc_buf_cfg;
 314	u32 ecc_bch_cfg;
 315	u32 clrflashstatus;
 316	u32 clrreadstatus;
 317};
 318
 319static inline struct qcom_nand_host *to_qcom_nand_host(struct nand_chip *chip)
 320{
 321	return container_of(chip, struct qcom_nand_host, chip);
 322}
 323
 324static inline struct qcom_nand_controller *
 325get_qcom_nand_controller(struct nand_chip *chip)
 326{
 327	return container_of(chip->controller, struct qcom_nand_controller,
 328			    controller);
 329}
 330
 331static inline u32 nandc_read(struct qcom_nand_controller *nandc, int offset)
 332{
 333	return ioread32(nandc->base + offset);
 334}
 335
 336static inline void nandc_write(struct qcom_nand_controller *nandc, int offset,
 337			       u32 val)
 338{
 339	iowrite32(val, nandc->base + offset);
 340}
 341
 342static __le32 *offset_to_nandc_reg(struct nandc_regs *regs, int offset)
 343{
 344	switch (offset) {
 345	case NAND_FLASH_CMD:
 346		return &regs->cmd;
 347	case NAND_ADDR0:
 348		return &regs->addr0;
 349	case NAND_ADDR1:
 350		return &regs->addr1;
 351	case NAND_FLASH_CHIP_SELECT:
 352		return &regs->chip_sel;
 353	case NAND_EXEC_CMD:
 354		return &regs->exec;
 355	case NAND_FLASH_STATUS:
 356		return &regs->clrflashstatus;
 357	case NAND_DEV0_CFG0:
 358		return &regs->cfg0;
 359	case NAND_DEV0_CFG1:
 360		return &regs->cfg1;
 361	case NAND_DEV0_ECC_CFG:
 362		return &regs->ecc_bch_cfg;
 363	case NAND_READ_STATUS:
 364		return &regs->clrreadstatus;
 365	case NAND_DEV_CMD1:
 366		return &regs->cmd1;
 367	case NAND_DEV_CMD1_RESTORE:
 368		return &regs->orig_cmd1;
 369	case NAND_DEV_CMD_VLD:
 370		return &regs->vld;
 371	case NAND_DEV_CMD_VLD_RESTORE:
 372		return &regs->orig_vld;
 373	case NAND_EBI2_ECC_BUF_CFG:
 374		return &regs->ecc_buf_cfg;
 375	default:
 376		return NULL;
 377	}
 378}
 379
 380static void nandc_set_reg(struct qcom_nand_controller *nandc, int offset,
 381			  u32 val)
 382{
 383	struct nandc_regs *regs = nandc->regs;
 384	__le32 *reg;
 385
 386	reg = offset_to_nandc_reg(regs, offset);
 387
 388	if (reg)
 389		*reg = cpu_to_le32(val);
 390}
 391
 392/* helper to configure address register values */
 393static void set_address(struct qcom_nand_host *host, u16 column, int page)
 394{
 395	struct nand_chip *chip = &host->chip;
 396	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
 397
 398	if (chip->options & NAND_BUSWIDTH_16)
 399		column >>= 1;
 400
 401	nandc_set_reg(nandc, NAND_ADDR0, page << 16 | column);
 402	nandc_set_reg(nandc, NAND_ADDR1, page >> 16 & 0xff);
 403}
 404
 405/*
 406 * update_rw_regs:	set up read/write register values, these will be
 407 *			written to the NAND controller registers via DMA
 408 *
 409 * @num_cw:		number of steps for the read/write operation
 410 * @read:		read or write operation
 411 */
 412static void update_rw_regs(struct qcom_nand_host *host, int num_cw, bool read)
 413{
 414	struct nand_chip *chip = &host->chip;
 415	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
 416	u32 cmd, cfg0, cfg1, ecc_bch_cfg;
 417
 418	if (read) {
 419		if (host->use_ecc)
 420			cmd = PAGE_READ_WITH_ECC | PAGE_ACC | LAST_PAGE;
 421		else
 422			cmd = PAGE_READ | PAGE_ACC | LAST_PAGE;
 423	} else {
 424			cmd = PROGRAM_PAGE | PAGE_ACC | LAST_PAGE;
 425	}
 426
 427	if (host->use_ecc) {
 428		cfg0 = (host->cfg0 & ~(7U << CW_PER_PAGE)) |
 429				(num_cw - 1) << CW_PER_PAGE;
 430
 431		cfg1 = host->cfg1;
 432		ecc_bch_cfg = host->ecc_bch_cfg;
 433	} else {
 434		cfg0 = (host->cfg0_raw & ~(7U << CW_PER_PAGE)) |
 435				(num_cw - 1) << CW_PER_PAGE;
 436
 437		cfg1 = host->cfg1_raw;
 438		ecc_bch_cfg = 1 << ECC_CFG_ECC_DISABLE;
 439	}
 440
 441	nandc_set_reg(nandc, NAND_FLASH_CMD, cmd);
 442	nandc_set_reg(nandc, NAND_DEV0_CFG0, cfg0);
 443	nandc_set_reg(nandc, NAND_DEV0_CFG1, cfg1);
 444	nandc_set_reg(nandc, NAND_DEV0_ECC_CFG, ecc_bch_cfg);
 445	nandc_set_reg(nandc, NAND_EBI2_ECC_BUF_CFG, host->ecc_buf_cfg);
 446	nandc_set_reg(nandc, NAND_FLASH_STATUS, host->clrflashstatus);
 447	nandc_set_reg(nandc, NAND_READ_STATUS, host->clrreadstatus);
 448	nandc_set_reg(nandc, NAND_EXEC_CMD, 1);
 449}
 450
 451static int prep_dma_desc(struct qcom_nand_controller *nandc, bool read,
 452			 int reg_off, const void *vaddr, int size,
 453			 bool flow_control)
 454{
 455	struct desc_info *desc;
 456	struct dma_async_tx_descriptor *dma_desc;
 457	struct scatterlist *sgl;
 458	struct dma_slave_config slave_conf;
 459	enum dma_transfer_direction dir_eng;
 460	int ret;
 461
 462	desc = kzalloc(sizeof(*desc), GFP_KERNEL);
 463	if (!desc)
 464		return -ENOMEM;
 465
 466	sgl = &desc->sgl;
 467
 468	sg_init_one(sgl, vaddr, size);
 469
 470	if (read) {
 471		dir_eng = DMA_DEV_TO_MEM;
 472		desc->dir = DMA_FROM_DEVICE;
 473	} else {
 474		dir_eng = DMA_MEM_TO_DEV;
 475		desc->dir = DMA_TO_DEVICE;
 476	}
 477
 478	ret = dma_map_sg(nandc->dev, sgl, 1, desc->dir);
 479	if (ret == 0) {
 480		ret = -ENOMEM;
 481		goto err;
 482	}
 483
 484	memset(&slave_conf, 0x00, sizeof(slave_conf));
 485
 486	slave_conf.device_fc = flow_control;
 487	if (read) {
 488		slave_conf.src_maxburst = 16;
 489		slave_conf.src_addr = nandc->base_dma + reg_off;
 490		slave_conf.slave_id = nandc->data_crci;
 491	} else {
 492		slave_conf.dst_maxburst = 16;
 493		slave_conf.dst_addr = nandc->base_dma + reg_off;
 494		slave_conf.slave_id = nandc->cmd_crci;
 495	}
 496
 497	ret = dmaengine_slave_config(nandc->chan, &slave_conf);
 498	if (ret) {
 499		dev_err(nandc->dev, "failed to configure dma channel\n");
 500		goto err;
 501	}
 502
 503	dma_desc = dmaengine_prep_slave_sg(nandc->chan, sgl, 1, dir_eng, 0);
 504	if (!dma_desc) {
 505		dev_err(nandc->dev, "failed to prepare desc\n");
 506		ret = -EINVAL;
 507		goto err;
 508	}
 509
 510	desc->dma_desc = dma_desc;
 511
 512	list_add_tail(&desc->node, &nandc->desc_list);
 513
 514	return 0;
 515err:
 516	kfree(desc);
 517
 518	return ret;
 519}
 520
 521/*
 522 * read_reg_dma:	prepares a descriptor to read a given number of
 523 *			contiguous registers to the reg_read_buf pointer
 524 *
 525 * @first:		offset of the first register in the contiguous block
 526 * @num_regs:		number of registers to read
 527 */
 528static int read_reg_dma(struct qcom_nand_controller *nandc, int first,
 529			int num_regs)
 530{
 531	bool flow_control = false;
 532	void *vaddr;
 533	int size;
 534
 535	if (first == NAND_READ_ID || first == NAND_FLASH_STATUS)
 536		flow_control = true;
 537
 538	size = num_regs * sizeof(u32);
 539	vaddr = nandc->reg_read_buf + nandc->reg_read_pos;
 540	nandc->reg_read_pos += num_regs;
 541
 542	return prep_dma_desc(nandc, true, first, vaddr, size, flow_control);
 543}
 544
 545/*
 546 * write_reg_dma:	prepares a descriptor to write a given number of
 547 *			contiguous registers
 548 *
 549 * @first:		offset of the first register in the contiguous block
 550 * @num_regs:		number of registers to write
 551 */
 552static int write_reg_dma(struct qcom_nand_controller *nandc, int first,
 553			 int num_regs)
 554{
 555	bool flow_control = false;
 556	struct nandc_regs *regs = nandc->regs;
 557	void *vaddr;
 558	int size;
 559
 560	vaddr = offset_to_nandc_reg(regs, first);
 561
 562	if (first == NAND_FLASH_CMD)
 563		flow_control = true;
 564
 565	if (first == NAND_DEV_CMD1_RESTORE)
 566		first = NAND_DEV_CMD1;
 567
 568	if (first == NAND_DEV_CMD_VLD_RESTORE)
 569		first = NAND_DEV_CMD_VLD;
 570
 571	size = num_regs * sizeof(u32);
 572
 573	return prep_dma_desc(nandc, false, first, vaddr, size, flow_control);
 574}
 575
 576/*
 577 * read_data_dma:	prepares a DMA descriptor to transfer data from the
 578 *			controller's internal buffer to the buffer 'vaddr'
 579 *
 580 * @reg_off:		offset within the controller's data buffer
 581 * @vaddr:		virtual address of the buffer we want to write to
 582 * @size:		DMA transaction size in bytes
 583 */
 584static int read_data_dma(struct qcom_nand_controller *nandc, int reg_off,
 585			 const u8 *vaddr, int size)
 586{
 587	return prep_dma_desc(nandc, true, reg_off, vaddr, size, false);
 588}
 589
 590/*
 591 * write_data_dma:	prepares a DMA descriptor to transfer data from
 592 *			'vaddr' to the controller's internal buffer
 593 *
 594 * @reg_off:		offset within the controller's data buffer
 595 * @vaddr:		virtual address of the buffer we want to read from
 596 * @size:		DMA transaction size in bytes
 597 */
 598static int write_data_dma(struct qcom_nand_controller *nandc, int reg_off,
 599			  const u8 *vaddr, int size)
 600{
 601	return prep_dma_desc(nandc, false, reg_off, vaddr, size, false);
 602}
 603
 604/*
 605 * helper to prepare dma descriptors to configure registers needed for reading a
 606 * codeword/step in a page
 607 */
 608static void config_cw_read(struct qcom_nand_controller *nandc)
 609{
 610	write_reg_dma(nandc, NAND_FLASH_CMD, 3);
 611	write_reg_dma(nandc, NAND_DEV0_CFG0, 3);
 612	write_reg_dma(nandc, NAND_EBI2_ECC_BUF_CFG, 1);
 613
 614	write_reg_dma(nandc, NAND_EXEC_CMD, 1);
 615
 616	read_reg_dma(nandc, NAND_FLASH_STATUS, 2);
 617	read_reg_dma(nandc, NAND_ERASED_CW_DETECT_STATUS, 1);
 618}
 619
 620/*
 621 * helpers to prepare dma descriptors used to configure registers needed for
 622 * writing a codeword/step in a page
 623 */
 624static void config_cw_write_pre(struct qcom_nand_controller *nandc)
 625{
 626	write_reg_dma(nandc, NAND_FLASH_CMD, 3);
 627	write_reg_dma(nandc, NAND_DEV0_CFG0, 3);
 628	write_reg_dma(nandc, NAND_EBI2_ECC_BUF_CFG, 1);
 629}
 630
 631static void config_cw_write_post(struct qcom_nand_controller *nandc)
 632{
 633	write_reg_dma(nandc, NAND_EXEC_CMD, 1);
 634
 635	read_reg_dma(nandc, NAND_FLASH_STATUS, 1);
 636
 637	write_reg_dma(nandc, NAND_FLASH_STATUS, 1);
 638	write_reg_dma(nandc, NAND_READ_STATUS, 1);
 639}
 640
 641/*
 642 * the following functions are used within chip->cmdfunc() to perform different
 643 * NAND_CMD_* commands
 644 */
 645
 646/* sets up descriptors for NAND_CMD_PARAM */
 647static int nandc_param(struct qcom_nand_host *host)
 648{
 649	struct nand_chip *chip = &host->chip;
 650	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
 651
 652	/*
 653	 * NAND_CMD_PARAM is called before we know much about the FLASH chip
 654	 * in use. we configure the controller to perform a raw read of 512
 655	 * bytes to read onfi params
 656	 */
 657	nandc_set_reg(nandc, NAND_FLASH_CMD, PAGE_READ | PAGE_ACC | LAST_PAGE);
 658	nandc_set_reg(nandc, NAND_ADDR0, 0);
 659	nandc_set_reg(nandc, NAND_ADDR1, 0);
 660	nandc_set_reg(nandc, NAND_DEV0_CFG0, 0 << CW_PER_PAGE
 661					| 512 << UD_SIZE_BYTES
 662					| 5 << NUM_ADDR_CYCLES
 663					| 0 << SPARE_SIZE_BYTES);
 664	nandc_set_reg(nandc, NAND_DEV0_CFG1, 7 << NAND_RECOVERY_CYCLES
 665					| 0 << CS_ACTIVE_BSY
 666					| 17 << BAD_BLOCK_BYTE_NUM
 667					| 1 << BAD_BLOCK_IN_SPARE_AREA
 668					| 2 << WR_RD_BSY_GAP
 669					| 0 << WIDE_FLASH
 670					| 1 << DEV0_CFG1_ECC_DISABLE);
 671	nandc_set_reg(nandc, NAND_EBI2_ECC_BUF_CFG, 1 << ECC_CFG_ECC_DISABLE);
 672
 673	/* configure CMD1 and VLD for ONFI param probing */
 674	nandc_set_reg(nandc, NAND_DEV_CMD_VLD,
 675		      (nandc->vld & ~(1 << READ_START_VLD))
 676		      | 0 << READ_START_VLD);
 677	nandc_set_reg(nandc, NAND_DEV_CMD1,
 678		      (nandc->cmd1 & ~(0xFF << READ_ADDR))
 679		      | NAND_CMD_PARAM << READ_ADDR);
 680
 681	nandc_set_reg(nandc, NAND_EXEC_CMD, 1);
 682
 683	nandc_set_reg(nandc, NAND_DEV_CMD1_RESTORE, nandc->cmd1);
 684	nandc_set_reg(nandc, NAND_DEV_CMD_VLD_RESTORE, nandc->vld);
 685
 686	write_reg_dma(nandc, NAND_DEV_CMD_VLD, 1);
 687	write_reg_dma(nandc, NAND_DEV_CMD1, 1);
 688
 689	nandc->buf_count = 512;
 690	memset(nandc->data_buffer, 0xff, nandc->buf_count);
 691
 692	config_cw_read(nandc);
 693
 694	read_data_dma(nandc, FLASH_BUF_ACC, nandc->data_buffer,
 695		      nandc->buf_count);
 696
 697	/* restore CMD1 and VLD regs */
 698	write_reg_dma(nandc, NAND_DEV_CMD1_RESTORE, 1);
 699	write_reg_dma(nandc, NAND_DEV_CMD_VLD_RESTORE, 1);
 700
 701	return 0;
 702}
 703
 704/* sets up descriptors for NAND_CMD_ERASE1 */
 705static int erase_block(struct qcom_nand_host *host, int page_addr)
 706{
 707	struct nand_chip *chip = &host->chip;
 708	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
 709
 710	nandc_set_reg(nandc, NAND_FLASH_CMD,
 711		      BLOCK_ERASE | PAGE_ACC | LAST_PAGE);
 712	nandc_set_reg(nandc, NAND_ADDR0, page_addr);
 713	nandc_set_reg(nandc, NAND_ADDR1, 0);
 714	nandc_set_reg(nandc, NAND_DEV0_CFG0,
 715		      host->cfg0_raw & ~(7 << CW_PER_PAGE));
 716	nandc_set_reg(nandc, NAND_DEV0_CFG1, host->cfg1_raw);
 717	nandc_set_reg(nandc, NAND_EXEC_CMD, 1);
 718	nandc_set_reg(nandc, NAND_FLASH_STATUS, host->clrflashstatus);
 719	nandc_set_reg(nandc, NAND_READ_STATUS, host->clrreadstatus);
 720
 721	write_reg_dma(nandc, NAND_FLASH_CMD, 3);
 722	write_reg_dma(nandc, NAND_DEV0_CFG0, 2);
 723	write_reg_dma(nandc, NAND_EXEC_CMD, 1);
 724
 725	read_reg_dma(nandc, NAND_FLASH_STATUS, 1);
 726
 727	write_reg_dma(nandc, NAND_FLASH_STATUS, 1);
 728	write_reg_dma(nandc, NAND_READ_STATUS, 1);
 729
 730	return 0;
 731}
 732
 733/* sets up descriptors for NAND_CMD_READID */
 734static int read_id(struct qcom_nand_host *host, int column)
 735{
 736	struct nand_chip *chip = &host->chip;
 737	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
 738
 739	if (column == -1)
 740		return 0;
 741
 742	nandc_set_reg(nandc, NAND_FLASH_CMD, FETCH_ID);
 743	nandc_set_reg(nandc, NAND_ADDR0, column);
 744	nandc_set_reg(nandc, NAND_ADDR1, 0);
 745	nandc_set_reg(nandc, NAND_FLASH_CHIP_SELECT, DM_EN);
 746	nandc_set_reg(nandc, NAND_EXEC_CMD, 1);
 747
 748	write_reg_dma(nandc, NAND_FLASH_CMD, 4);
 749	write_reg_dma(nandc, NAND_EXEC_CMD, 1);
 750
 751	read_reg_dma(nandc, NAND_READ_ID, 1);
 752
 753	return 0;
 754}
 755
 756/* sets up descriptors for NAND_CMD_RESET */
 757static int reset(struct qcom_nand_host *host)
 758{
 759	struct nand_chip *chip = &host->chip;
 760	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
 761
 762	nandc_set_reg(nandc, NAND_FLASH_CMD, RESET_DEVICE);
 763	nandc_set_reg(nandc, NAND_EXEC_CMD, 1);
 764
 765	write_reg_dma(nandc, NAND_FLASH_CMD, 1);
 766	write_reg_dma(nandc, NAND_EXEC_CMD, 1);
 767
 768	read_reg_dma(nandc, NAND_FLASH_STATUS, 1);
 769
 770	return 0;
 771}
 772
 773/* helpers to submit/free our list of dma descriptors */
 774static int submit_descs(struct qcom_nand_controller *nandc)
 775{
 776	struct desc_info *desc;
 777	dma_cookie_t cookie = 0;
 778
 779	list_for_each_entry(desc, &nandc->desc_list, node)
 780		cookie = dmaengine_submit(desc->dma_desc);
 781
 782	if (dma_sync_wait(nandc->chan, cookie) != DMA_COMPLETE)
 783		return -ETIMEDOUT;
 784
 785	return 0;
 786}
 787
 788static void free_descs(struct qcom_nand_controller *nandc)
 789{
 790	struct desc_info *desc, *n;
 791
 792	list_for_each_entry_safe(desc, n, &nandc->desc_list, node) {
 793		list_del(&desc->node);
 794		dma_unmap_sg(nandc->dev, &desc->sgl, 1, desc->dir);
 795		kfree(desc);
 796	}
 797}
 798
 799/* reset the register read buffer for next NAND operation */
 800static void clear_read_regs(struct qcom_nand_controller *nandc)
 801{
 802	nandc->reg_read_pos = 0;
 803	memset(nandc->reg_read_buf, 0,
 804	       MAX_REG_RD * sizeof(*nandc->reg_read_buf));
 805}
 806
 807static void pre_command(struct qcom_nand_host *host, int command)
 808{
 809	struct nand_chip *chip = &host->chip;
 810	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
 811
 812	nandc->buf_count = 0;
 813	nandc->buf_start = 0;
 814	host->use_ecc = false;
 815	host->last_command = command;
 816
 817	clear_read_regs(nandc);
 818}
 819
 820/*
 821 * this is called after NAND_CMD_PAGEPROG and NAND_CMD_ERASE1 to set our
 822 * privately maintained status byte, this status byte can be read after
 823 * NAND_CMD_STATUS is called
 824 */
 825static void parse_erase_write_errors(struct qcom_nand_host *host, int command)
 826{
 827	struct nand_chip *chip = &host->chip;
 828	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
 829	struct nand_ecc_ctrl *ecc = &chip->ecc;
 830	int num_cw;
 831	int i;
 832
 833	num_cw = command == NAND_CMD_PAGEPROG ? ecc->steps : 1;
 834
 835	for (i = 0; i < num_cw; i++) {
 836		u32 flash_status = le32_to_cpu(nandc->reg_read_buf[i]);
 837
 838		if (flash_status & FS_MPU_ERR)
 839			host->status &= ~NAND_STATUS_WP;
 840
 841		if (flash_status & FS_OP_ERR || (i == (num_cw - 1) &&
 842						 (flash_status &
 843						  FS_DEVICE_STS_ERR)))
 844			host->status |= NAND_STATUS_FAIL;
 845	}
 846}
 847
 848static void post_command(struct qcom_nand_host *host, int command)
 849{
 850	struct nand_chip *chip = &host->chip;
 851	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
 852
 853	switch (command) {
 854	case NAND_CMD_READID:
 855		memcpy(nandc->data_buffer, nandc->reg_read_buf,
 856		       nandc->buf_count);
 857		break;
 858	case NAND_CMD_PAGEPROG:
 859	case NAND_CMD_ERASE1:
 860		parse_erase_write_errors(host, command);
 861		break;
 862	default:
 863		break;
 864	}
 865}
 866
 867/*
 868 * Implements chip->cmdfunc. It's  only used for a limited set of commands.
 869 * The rest of the commands wouldn't be called by upper layers. For example,
 870 * NAND_CMD_READOOB would never be called because we have our own versions
 871 * of read_oob ops for nand_ecc_ctrl.
 872 */
 873static void qcom_nandc_command(struct mtd_info *mtd, unsigned int command,
 874			       int column, int page_addr)
 875{
 876	struct nand_chip *chip = mtd_to_nand(mtd);
 877	struct qcom_nand_host *host = to_qcom_nand_host(chip);
 878	struct nand_ecc_ctrl *ecc = &chip->ecc;
 879	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
 880	bool wait = false;
 881	int ret = 0;
 882
 883	pre_command(host, command);
 884
 885	switch (command) {
 886	case NAND_CMD_RESET:
 887		ret = reset(host);
 888		wait = true;
 889		break;
 890
 891	case NAND_CMD_READID:
 892		nandc->buf_count = 4;
 893		ret = read_id(host, column);
 894		wait = true;
 895		break;
 896
 897	case NAND_CMD_PARAM:
 898		ret = nandc_param(host);
 899		wait = true;
 900		break;
 901
 902	case NAND_CMD_ERASE1:
 903		ret = erase_block(host, page_addr);
 904		wait = true;
 905		break;
 906
 907	case NAND_CMD_READ0:
 908		/* we read the entire page for now */
 909		WARN_ON(column != 0);
 910
 911		host->use_ecc = true;
 912		set_address(host, 0, page_addr);
 913		update_rw_regs(host, ecc->steps, true);
 914		break;
 915
 916	case NAND_CMD_SEQIN:
 917		WARN_ON(column != 0);
 918		set_address(host, 0, page_addr);
 919		break;
 920
 921	case NAND_CMD_PAGEPROG:
 922	case NAND_CMD_STATUS:
 923	case NAND_CMD_NONE:
 924	default:
 925		break;
 926	}
 927
 928	if (ret) {
 929		dev_err(nandc->dev, "failure executing command %d\n",
 930			command);
 931		free_descs(nandc);
 932		return;
 933	}
 934
 935	if (wait) {
 936		ret = submit_descs(nandc);
 937		if (ret)
 938			dev_err(nandc->dev,
 939				"failure submitting descs for command %d\n",
 940				command);
 941	}
 942
 943	free_descs(nandc);
 944
 945	post_command(host, command);
 946}
 947
 948/*
 949 * when using BCH ECC, the HW flags an error in NAND_FLASH_STATUS if it read
 950 * an erased CW, and reports an erased CW in NAND_ERASED_CW_DETECT_STATUS.
 951 *
 952 * when using RS ECC, the HW reports the same erros when reading an erased CW,
 953 * but it notifies that it is an erased CW by placing special characters at
 954 * certain offsets in the buffer.
 955 *
 956 * verify if the page is erased or not, and fix up the page for RS ECC by
 957 * replacing the special characters with 0xff.
 958 */
 959static bool erased_chunk_check_and_fixup(u8 *data_buf, int data_len)
 960{
 961	u8 empty1, empty2;
 962
 963	/*
 964	 * an erased page flags an error in NAND_FLASH_STATUS, check if the page
 965	 * is erased by looking for 0x54s at offsets 3 and 175 from the
 966	 * beginning of each codeword
 967	 */
 968
 969	empty1 = data_buf[3];
 970	empty2 = data_buf[175];
 971
 972	/*
 973	 * if the erased codework markers, if they exist override them with
 974	 * 0xffs
 975	 */
 976	if ((empty1 == 0x54 && empty2 == 0xff) ||
 977	    (empty1 == 0xff && empty2 == 0x54)) {
 978		data_buf[3] = 0xff;
 979		data_buf[175] = 0xff;
 980	}
 981
 982	/*
 983	 * check if the entire chunk contains 0xffs or not. if it doesn't, then
 984	 * restore the original values at the special offsets
 985	 */
 986	if (memchr_inv(data_buf, 0xff, data_len)) {
 987		data_buf[3] = empty1;
 988		data_buf[175] = empty2;
 989
 990		return false;
 991	}
 992
 993	return true;
 994}
 995
 996struct read_stats {
 997	__le32 flash;
 998	__le32 buffer;
 999	__le32 erased_cw;
1000};
1001
1002/*
1003 * reads back status registers set by the controller to notify page read
1004 * errors. this is equivalent to what 'ecc->correct()' would do.
1005 */
1006static int parse_read_errors(struct qcom_nand_host *host, u8 *data_buf,
1007			     u8 *oob_buf)
1008{
1009	struct nand_chip *chip = &host->chip;
1010	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
1011	struct mtd_info *mtd = nand_to_mtd(chip);
1012	struct nand_ecc_ctrl *ecc = &chip->ecc;
1013	unsigned int max_bitflips = 0;
1014	struct read_stats *buf;
1015	int i;
1016
1017	buf = (struct read_stats *)nandc->reg_read_buf;
1018
1019	for (i = 0; i < ecc->steps; i++, buf++) {
1020		u32 flash, buffer, erased_cw;
1021		int data_len, oob_len;
1022
1023		if (i == (ecc->steps - 1)) {
1024			data_len = ecc->size - ((ecc->steps - 1) << 2);
1025			oob_len = ecc->steps << 2;
1026		} else {
1027			data_len = host->cw_data;
1028			oob_len = 0;
1029		}
1030
1031		flash = le32_to_cpu(buf->flash);
1032		buffer = le32_to_cpu(buf->buffer);
1033		erased_cw = le32_to_cpu(buf->erased_cw);
1034
1035		if (flash & (FS_OP_ERR | FS_MPU_ERR)) {
1036			bool erased;
1037
1038			/* ignore erased codeword errors */
1039			if (host->bch_enabled) {
1040				erased = (erased_cw & ERASED_CW) == ERASED_CW ?
1041					 true : false;
1042			} else {
1043				erased = erased_chunk_check_and_fixup(data_buf,
1044								      data_len);
1045			}
1046
1047			if (erased) {
1048				data_buf += data_len;
1049				if (oob_buf)
1050					oob_buf += oob_len + ecc->bytes;
1051				continue;
1052			}
1053
1054			if (buffer & BS_UNCORRECTABLE_BIT) {
1055				int ret, ecclen, extraooblen;
1056				void *eccbuf;
1057
1058				eccbuf = oob_buf ? oob_buf + oob_len : NULL;
1059				ecclen = oob_buf ? host->ecc_bytes_hw : 0;
1060				extraooblen = oob_buf ? oob_len : 0;
1061
1062				/*
1063				 * make sure it isn't an erased page reported
1064				 * as not-erased by HW because of a few bitflips
1065				 */
1066				ret = nand_check_erased_ecc_chunk(data_buf,
1067					data_len, eccbuf, ecclen, oob_buf,
1068					extraooblen, ecc->strength);
1069				if (ret < 0) {
1070					mtd->ecc_stats.failed++;
1071				} else {
1072					mtd->ecc_stats.corrected += ret;
1073					max_bitflips =
1074						max_t(unsigned int, max_bitflips, ret);
1075				}
1076			}
1077		} else {
1078			unsigned int stat;
1079
1080			stat = buffer & BS_CORRECTABLE_ERR_MSK;
1081			mtd->ecc_stats.corrected += stat;
1082			max_bitflips = max(max_bitflips, stat);
1083		}
1084
1085		data_buf += data_len;
1086		if (oob_buf)
1087			oob_buf += oob_len + ecc->bytes;
1088	}
1089
1090	return max_bitflips;
1091}
1092
1093/*
1094 * helper to perform the actual page read operation, used by ecc->read_page(),
1095 * ecc->read_oob()
1096 */
1097static int read_page_ecc(struct qcom_nand_host *host, u8 *data_buf,
1098			 u8 *oob_buf)
1099{
1100	struct nand_chip *chip = &host->chip;
1101	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
1102	struct nand_ecc_ctrl *ecc = &chip->ecc;
1103	int i, ret;
1104
1105	/* queue cmd descs for each codeword */
1106	for (i = 0; i < ecc->steps; i++) {
1107		int data_size, oob_size;
1108
1109		if (i == (ecc->steps - 1)) {
1110			data_size = ecc->size - ((ecc->steps - 1) << 2);
1111			oob_size = (ecc->steps << 2) + host->ecc_bytes_hw +
1112				   host->spare_bytes;
1113		} else {
1114			data_size = host->cw_data;
1115			oob_size = host->ecc_bytes_hw + host->spare_bytes;
1116		}
1117
1118		config_cw_read(nandc);
1119
1120		if (data_buf)
1121			read_data_dma(nandc, FLASH_BUF_ACC, data_buf,
1122				      data_size);
1123
1124		/*
1125		 * when ecc is enabled, the controller doesn't read the real
1126		 * or dummy bad block markers in each chunk. To maintain a
1127		 * consistent layout across RAW and ECC reads, we just
1128		 * leave the real/dummy BBM offsets empty (i.e, filled with
1129		 * 0xffs)
1130		 */
1131		if (oob_buf) {
1132			int j;
1133
1134			for (j = 0; j < host->bbm_size; j++)
1135				*oob_buf++ = 0xff;
1136
1137			read_data_dma(nandc, FLASH_BUF_ACC + data_size,
1138				      oob_buf, oob_size);
1139		}
1140
1141		if (data_buf)
1142			data_buf += data_size;
1143		if (oob_buf)
1144			oob_buf += oob_size;
1145	}
1146
1147	ret = submit_descs(nandc);
1148	if (ret)
1149		dev_err(nandc->dev, "failure to read page/oob\n");
1150
1151	free_descs(nandc);
1152
1153	return ret;
1154}
1155
1156/*
1157 * a helper that copies the last step/codeword of a page (containing free oob)
1158 * into our local buffer
1159 */
1160static int copy_last_cw(struct qcom_nand_host *host, int page)
1161{
1162	struct nand_chip *chip = &host->chip;
1163	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
1164	struct nand_ecc_ctrl *ecc = &chip->ecc;
1165	int size;
1166	int ret;
1167
1168	clear_read_regs(nandc);
1169
1170	size = host->use_ecc ? host->cw_data : host->cw_size;
1171
1172	/* prepare a clean read buffer */
1173	memset(nandc->data_buffer, 0xff, size);
1174
1175	set_address(host, host->cw_size * (ecc->steps - 1), page);
1176	update_rw_regs(host, 1, true);
1177
1178	config_cw_read(nandc);
1179
1180	read_data_dma(nandc, FLASH_BUF_ACC, nandc->data_buffer, size);
1181
1182	ret = submit_descs(nandc);
1183	if (ret)
1184		dev_err(nandc->dev, "failed to copy last codeword\n");
1185
1186	free_descs(nandc);
1187
1188	return ret;
1189}
1190
1191/* implements ecc->read_page() */
1192static int qcom_nandc_read_page(struct mtd_info *mtd, struct nand_chip *chip,
1193				uint8_t *buf, int oob_required, int page)
1194{
1195	struct qcom_nand_host *host = to_qcom_nand_host(chip);
1196	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
1197	u8 *data_buf, *oob_buf = NULL;
1198	int ret;
1199
1200	data_buf = buf;
1201	oob_buf = oob_required ? chip->oob_poi : NULL;
1202
1203	ret = read_page_ecc(host, data_buf, oob_buf);
1204	if (ret) {
1205		dev_err(nandc->dev, "failure to read page\n");
1206		return ret;
1207	}
1208
1209	return parse_read_errors(host, data_buf, oob_buf);
1210}
1211
1212/* implements ecc->read_page_raw() */
1213static int qcom_nandc_read_page_raw(struct mtd_info *mtd,
1214				    struct nand_chip *chip, uint8_t *buf,
1215				    int oob_required, int page)
1216{
1217	struct qcom_nand_host *host = to_qcom_nand_host(chip);
1218	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
1219	u8 *data_buf, *oob_buf;
1220	struct nand_ecc_ctrl *ecc = &chip->ecc;
1221	int i, ret;
1222
1223	data_buf = buf;
1224	oob_buf = chip->oob_poi;
1225
1226	host->use_ecc = false;
1227	update_rw_regs(host, ecc->steps, true);
1228
1229	for (i = 0; i < ecc->steps; i++) {
1230		int data_size1, data_size2, oob_size1, oob_size2;
1231		int reg_off = FLASH_BUF_ACC;
1232
1233		data_size1 = mtd->writesize - host->cw_size * (ecc->steps - 1);
1234		oob_size1 = host->bbm_size;
1235
1236		if (i == (ecc->steps - 1)) {
1237			data_size2 = ecc->size - data_size1 -
1238				     ((ecc->steps - 1) << 2);
1239			oob_size2 = (ecc->steps << 2) + host->ecc_bytes_hw +
1240				    host->spare_bytes;
1241		} else {
1242			data_size2 = host->cw_data - data_size1;
1243			oob_size2 = host->ecc_bytes_hw + host->spare_bytes;
1244		}
1245
1246		config_cw_read(nandc);
1247
1248		read_data_dma(nandc, reg_off, data_buf, data_size1);
1249		reg_off += data_size1;
1250		data_buf += data_size1;
1251
1252		read_data_dma(nandc, reg_off, oob_buf, oob_size1);
1253		reg_off += oob_size1;
1254		oob_buf += oob_size1;
1255
1256		read_data_dma(nandc, reg_off, data_buf, data_size2);
1257		reg_off += data_size2;
1258		data_buf += data_size2;
1259
1260		read_data_dma(nandc, reg_off, oob_buf, oob_size2);
1261		oob_buf += oob_size2;
1262	}
1263
1264	ret = submit_descs(nandc);
1265	if (ret)
1266		dev_err(nandc->dev, "failure to read raw page\n");
1267
1268	free_descs(nandc);
1269
1270	return 0;
1271}
1272
1273/* implements ecc->read_oob() */
1274static int qcom_nandc_read_oob(struct mtd_info *mtd, struct nand_chip *chip,
1275			       int page)
1276{
1277	struct qcom_nand_host *host = to_qcom_nand_host(chip);
1278	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
1279	struct nand_ecc_ctrl *ecc = &chip->ecc;
1280	int ret;
1281
1282	clear_read_regs(nandc);
1283
1284	host->use_ecc = true;
1285	set_address(host, 0, page);
1286	update_rw_regs(host, ecc->steps, true);
1287
1288	ret = read_page_ecc(host, NULL, chip->oob_poi);
1289	if (ret)
1290		dev_err(nandc->dev, "failure to read oob\n");
1291
1292	return ret;
1293}
1294
1295/* implements ecc->write_page() */
1296static int qcom_nandc_write_page(struct mtd_info *mtd, struct nand_chip *chip,
1297				 const uint8_t *buf, int oob_required, int page)
1298{
1299	struct qcom_nand_host *host = to_qcom_nand_host(chip);
1300	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
1301	struct nand_ecc_ctrl *ecc = &chip->ecc;
1302	u8 *data_buf, *oob_buf;
1303	int i, ret;
1304
1305	clear_read_regs(nandc);
1306
1307	data_buf = (u8 *)buf;
1308	oob_buf = chip->oob_poi;
1309
1310	host->use_ecc = true;
1311	update_rw_regs(host, ecc->steps, false);
1312
1313	for (i = 0; i < ecc->steps; i++) {
1314		int data_size, oob_size;
1315
1316		if (i == (ecc->steps - 1)) {
1317			data_size = ecc->size - ((ecc->steps - 1) << 2);
1318			oob_size = (ecc->steps << 2) + host->ecc_bytes_hw +
1319				   host->spare_bytes;
1320		} else {
1321			data_size = host->cw_data;
1322			oob_size = ecc->bytes;
1323		}
1324
1325		config_cw_write_pre(nandc);
1326
1327		write_data_dma(nandc, FLASH_BUF_ACC, data_buf, data_size);
1328
1329		/*
1330		 * when ECC is enabled, we don't really need to write anything
1331		 * to oob for the first n - 1 codewords since these oob regions
1332		 * just contain ECC bytes that's written by the controller
1333		 * itself. For the last codeword, we skip the bbm positions and
1334		 * write to the free oob area.
1335		 */
1336		if (i == (ecc->steps - 1)) {
1337			oob_buf += host->bbm_size;
1338
1339			write_data_dma(nandc, FLASH_BUF_ACC + data_size,
1340				       oob_buf, oob_size);
1341		}
1342
1343		config_cw_write_post(nandc);
1344
1345		data_buf += data_size;
1346		oob_buf += oob_size;
1347	}
1348
1349	ret = submit_descs(nandc);
1350	if (ret)
1351		dev_err(nandc->dev, "failure to write page\n");
1352
1353	free_descs(nandc);
1354
1355	return ret;
1356}
1357
1358/* implements ecc->write_page_raw() */
1359static int qcom_nandc_write_page_raw(struct mtd_info *mtd,
1360				     struct nand_chip *chip, const uint8_t *buf,
1361				     int oob_required, int page)
1362{
1363	struct qcom_nand_host *host = to_qcom_nand_host(chip);
1364	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
1365	struct nand_ecc_ctrl *ecc = &chip->ecc;
1366	u8 *data_buf, *oob_buf;
1367	int i, ret;
1368
1369	clear_read_regs(nandc);
1370
1371	data_buf = (u8 *)buf;
1372	oob_buf = chip->oob_poi;
1373
1374	host->use_ecc = false;
1375	update_rw_regs(host, ecc->steps, false);
1376
1377	for (i = 0; i < ecc->steps; i++) {
1378		int data_size1, data_size2, oob_size1, oob_size2;
1379		int reg_off = FLASH_BUF_ACC;
1380
1381		data_size1 = mtd->writesize - host->cw_size * (ecc->steps - 1);
1382		oob_size1 = host->bbm_size;
1383
1384		if (i == (ecc->steps - 1)) {
1385			data_size2 = ecc->size - data_size1 -
1386				     ((ecc->steps - 1) << 2);
1387			oob_size2 = (ecc->steps << 2) + host->ecc_bytes_hw +
1388				    host->spare_bytes;
1389		} else {
1390			data_size2 = host->cw_data - data_size1;
1391			oob_size2 = host->ecc_bytes_hw + host->spare_bytes;
1392		}
1393
1394		config_cw_write_pre(nandc);
1395
1396		write_data_dma(nandc, reg_off, data_buf, data_size1);
1397		reg_off += data_size1;
1398		data_buf += data_size1;
1399
1400		write_data_dma(nandc, reg_off, oob_buf, oob_size1);
1401		reg_off += oob_size1;
1402		oob_buf += oob_size1;
1403
1404		write_data_dma(nandc, reg_off, data_buf, data_size2);
1405		reg_off += data_size2;
1406		data_buf += data_size2;
1407
1408		write_data_dma(nandc, reg_off, oob_buf, oob_size2);
1409		oob_buf += oob_size2;
1410
1411		config_cw_write_post(nandc);
1412	}
1413
1414	ret = submit_descs(nandc);
1415	if (ret)
1416		dev_err(nandc->dev, "failure to write raw page\n");
1417
1418	free_descs(nandc);
1419
1420	return ret;
1421}
1422
1423/*
1424 * implements ecc->write_oob()
1425 *
1426 * the NAND controller cannot write only data or only oob within a codeword,
1427 * since ecc is calculated for the combined codeword. we first copy the
1428 * entire contents for the last codeword(data + oob), replace the old oob
1429 * with the new one in chip->oob_poi, and then write the entire codeword.
1430 * this read-copy-write operation results in a slight performance loss.
1431 */
1432static int qcom_nandc_write_oob(struct mtd_info *mtd, struct nand_chip *chip,
1433				int page)
1434{
1435	struct qcom_nand_host *host = to_qcom_nand_host(chip);
1436	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
1437	struct nand_ecc_ctrl *ecc = &chip->ecc;
1438	u8 *oob = chip->oob_poi;
1439	int data_size, oob_size;
1440	int ret, status = 0;
1441
1442	host->use_ecc = true;
1443
1444	ret = copy_last_cw(host, page);
1445	if (ret)
1446		return ret;
1447
1448	clear_read_regs(nandc);
1449
1450	/* calculate the data and oob size for the last codeword/step */
1451	data_size = ecc->size - ((ecc->steps - 1) << 2);
1452	oob_size = mtd->oobavail;
1453
1454	/* override new oob content to last codeword */
1455	mtd_ooblayout_get_databytes(mtd, nandc->data_buffer + data_size, oob,
1456				    0, mtd->oobavail);
1457
1458	set_address(host, host->cw_size * (ecc->steps - 1), page);
1459	update_rw_regs(host, 1, false);
1460
1461	config_cw_write_pre(nandc);
1462	write_data_dma(nandc, FLASH_BUF_ACC, nandc->data_buffer,
1463		       data_size + oob_size);
1464	config_cw_write_post(nandc);
1465
1466	ret = submit_descs(nandc);
1467
1468	free_descs(nandc);
1469
1470	if (ret) {
1471		dev_err(nandc->dev, "failure to write oob\n");
1472		return -EIO;
1473	}
1474
1475	chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
1476
1477	status = chip->waitfunc(mtd, chip);
1478
1479	return status & NAND_STATUS_FAIL ? -EIO : 0;
1480}
1481
1482static int qcom_nandc_block_bad(struct mtd_info *mtd, loff_t ofs)
1483{
1484	struct nand_chip *chip = mtd_to_nand(mtd);
1485	struct qcom_nand_host *host = to_qcom_nand_host(chip);
1486	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
1487	struct nand_ecc_ctrl *ecc = &chip->ecc;
1488	int page, ret, bbpos, bad = 0;
1489	u32 flash_status;
1490
1491	page = (int)(ofs >> chip->page_shift) & chip->pagemask;
1492
1493	/*
1494	 * configure registers for a raw sub page read, the address is set to
1495	 * the beginning of the last codeword, we don't care about reading ecc
1496	 * portion of oob. we just want the first few bytes from this codeword
1497	 * that contains the BBM
1498	 */
1499	host->use_ecc = false;
1500
1501	ret = copy_last_cw(host, page);
1502	if (ret)
1503		goto err;
1504
1505	flash_status = le32_to_cpu(nandc->reg_read_buf[0]);
1506
1507	if (flash_status & (FS_OP_ERR | FS_MPU_ERR)) {
1508		dev_warn(nandc->dev, "error when trying to read BBM\n");
1509		goto err;
1510	}
1511
1512	bbpos = mtd->writesize - host->cw_size * (ecc->steps - 1);
1513
1514	bad = nandc->data_buffer[bbpos] != 0xff;
1515
1516	if (chip->options & NAND_BUSWIDTH_16)
1517		bad = bad || (nandc->data_buffer[bbpos + 1] != 0xff);
1518err:
1519	return bad;
1520}
1521
1522static int qcom_nandc_block_markbad(struct mtd_info *mtd, loff_t ofs)
1523{
1524	struct nand_chip *chip = mtd_to_nand(mtd);
1525	struct qcom_nand_host *host = to_qcom_nand_host(chip);
1526	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
1527	struct nand_ecc_ctrl *ecc = &chip->ecc;
1528	int page, ret, status = 0;
1529
1530	clear_read_regs(nandc);
1531
1532	/*
1533	 * to mark the BBM as bad, we flash the entire last codeword with 0s.
1534	 * we don't care about the rest of the content in the codeword since
1535	 * we aren't going to use this block again
1536	 */
1537	memset(nandc->data_buffer, 0x00, host->cw_size);
1538
1539	page = (int)(ofs >> chip->page_shift) & chip->pagemask;
1540
1541	/* prepare write */
1542	host->use_ecc = false;
1543	set_address(host, host->cw_size * (ecc->steps - 1), page);
1544	update_rw_regs(host, 1, false);
1545
1546	config_cw_write_pre(nandc);
1547	write_data_dma(nandc, FLASH_BUF_ACC, nandc->data_buffer, host->cw_size);
1548	config_cw_write_post(nandc);
1549
1550	ret = submit_descs(nandc);
1551
1552	free_descs(nandc);
1553
1554	if (ret) {
1555		dev_err(nandc->dev, "failure to update BBM\n");
1556		return -EIO;
1557	}
1558
1559	chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
1560
1561	status = chip->waitfunc(mtd, chip);
1562
1563	return status & NAND_STATUS_FAIL ? -EIO : 0;
1564}
1565
1566/*
1567 * the three functions below implement chip->read_byte(), chip->read_buf()
1568 * and chip->write_buf() respectively. these aren't used for
1569 * reading/writing page data, they are used for smaller data like reading
1570 * id, status etc
1571 */
1572static uint8_t qcom_nandc_read_byte(struct mtd_info *mtd)
1573{
1574	struct nand_chip *chip = mtd_to_nand(mtd);
1575	struct qcom_nand_host *host = to_qcom_nand_host(chip);
1576	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
1577	u8 *buf = nandc->data_buffer;
1578	u8 ret = 0x0;
1579
1580	if (host->last_command == NAND_CMD_STATUS) {
1581		ret = host->status;
1582
1583		host->status = NAND_STATUS_READY | NAND_STATUS_WP;
1584
1585		return ret;
1586	}
1587
1588	if (nandc->buf_start < nandc->buf_count)
1589		ret = buf[nandc->buf_start++];
1590
1591	return ret;
1592}
1593
1594static void qcom_nandc_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
1595{
1596	struct nand_chip *chip = mtd_to_nand(mtd);
1597	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
1598	int real_len = min_t(size_t, len, nandc->buf_count - nandc->buf_start);
1599
1600	memcpy(buf, nandc->data_buffer + nandc->buf_start, real_len);
1601	nandc->buf_start += real_len;
1602}
1603
1604static void qcom_nandc_write_buf(struct mtd_info *mtd, const uint8_t *buf,
1605				 int len)
1606{
1607	struct nand_chip *chip = mtd_to_nand(mtd);
1608	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
1609	int real_len = min_t(size_t, len, nandc->buf_count - nandc->buf_start);
1610
1611	memcpy(nandc->data_buffer + nandc->buf_start, buf, real_len);
1612
1613	nandc->buf_start += real_len;
1614}
1615
1616/* we support only one external chip for now */
1617static void qcom_nandc_select_chip(struct mtd_info *mtd, int chipnr)
1618{
1619	struct nand_chip *chip = mtd_to_nand(mtd);
1620	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
1621
1622	if (chipnr <= 0)
1623		return;
1624
1625	dev_warn(nandc->dev, "invalid chip select\n");
1626}
1627
1628/*
1629 * NAND controller page layout info
1630 *
1631 * Layout with ECC enabled:
1632 *
1633 * |----------------------|  |---------------------------------|
1634 * |           xx.......yy|  |             *********xx.......yy|
1635 * |    DATA   xx..ECC..yy|  |    DATA     **SPARE**xx..ECC..yy|
1636 * |   (516)   xx.......yy|  |  (516-n*4)  **(n*4)**xx.......yy|
1637 * |           xx.......yy|  |             *********xx.......yy|
1638 * |----------------------|  |---------------------------------|
1639 *     codeword 1,2..n-1                  codeword n
1640 *  <---(528/532 Bytes)-->    <-------(528/532 Bytes)--------->
1641 *
1642 * n = Number of codewords in the page
1643 * . = ECC bytes
1644 * * = Spare/free bytes
1645 * x = Unused byte(s)
1646 * y = Reserved byte(s)
1647 *
1648 * 2K page: n = 4, spare = 16 bytes
1649 * 4K page: n = 8, spare = 32 bytes
1650 * 8K page: n = 16, spare = 64 bytes
1651 *
1652 * the qcom nand controller operates at a sub page/codeword level. each
1653 * codeword is 528 and 532 bytes for 4 bit and 8 bit ECC modes respectively.
1654 * the number of ECC bytes vary based on the ECC strength and the bus width.
1655 *
1656 * the first n - 1 codewords contains 516 bytes of user data, the remaining
1657 * 12/16 bytes consist of ECC and reserved data. The nth codeword contains
1658 * both user data and spare(oobavail) bytes that sum up to 516 bytes.
1659 *
1660 * When we access a page with ECC enabled, the reserved bytes(s) are not
1661 * accessible at all. When reading, we fill up these unreadable positions
1662 * with 0xffs. When writing, the controller skips writing the inaccessible
1663 * bytes.
1664 *
1665 * Layout with ECC disabled:
1666 *
1667 * |------------------------------|  |---------------------------------------|
1668 * |         yy          xx.......|  |         bb          *********xx.......|
1669 * |  DATA1  yy  DATA2   xx..ECC..|  |  DATA1  bb  DATA2   **SPARE**xx..ECC..|
1670 * | (size1) yy (size2)  xx.......|  | (size1) bb (size2)  **(n*4)**xx.......|
1671 * |         yy          xx.......|  |         bb          *********xx.......|
1672 * |------------------------------|  |---------------------------------------|
1673 *         codeword 1,2..n-1                        codeword n
1674 *  <-------(528/532 Bytes)------>    <-----------(528/532 Bytes)----------->
1675 *
1676 * n = Number of codewords in the page
1677 * . = ECC bytes
1678 * * = Spare/free bytes
1679 * x = Unused byte(s)
1680 * y = Dummy Bad Bock byte(s)
1681 * b = Real Bad Block byte(s)
1682 * size1/size2 = function of codeword size and 'n'
1683 *
1684 * when the ECC block is disabled, one reserved byte (or two for 16 bit bus
1685 * width) is now accessible. For the first n - 1 codewords, these are dummy Bad
1686 * Block Markers. In the last codeword, this position contains the real BBM
1687 *
1688 * In order to have a consistent layout between RAW and ECC modes, we assume
1689 * the following OOB layout arrangement:
1690 *
1691 * |-----------|  |--------------------|
1692 * |yyxx.......|  |bb*********xx.......|
1693 * |yyxx..ECC..|  |bb*FREEOOB*xx..ECC..|
1694 * |yyxx.......|  |bb*********xx.......|
1695 * |yyxx.......|  |bb*********xx.......|
1696 * |-----------|  |--------------------|
1697 *  first n - 1       nth OOB region
1698 *  OOB regions
1699 *
1700 * n = Number of codewords in the page
1701 * . = ECC bytes
1702 * * = FREE OOB bytes
1703 * y = Dummy bad block byte(s) (inaccessible when ECC enabled)
1704 * x = Unused byte(s)
1705 * b = Real bad block byte(s) (inaccessible when ECC enabled)
1706 *
1707 * This layout is read as is when ECC is disabled. When ECC is enabled, the
1708 * inaccessible Bad Block byte(s) are ignored when we write to a page/oob,
1709 * and assumed as 0xffs when we read a page/oob. The ECC, unused and
1710 * dummy/real bad block bytes are grouped as ecc bytes (i.e, ecc->bytes is
1711 * the sum of the three).
1712 */
1713static int qcom_nand_ooblayout_ecc(struct mtd_info *mtd, int section,
1714				   struct mtd_oob_region *oobregion)
1715{
1716	struct nand_chip *chip = mtd_to_nand(mtd);
1717	struct qcom_nand_host *host = to_qcom_nand_host(chip);
1718	struct nand_ecc_ctrl *ecc = &chip->ecc;
1719
1720	if (section > 1)
1721		return -ERANGE;
1722
1723	if (!section) {
1724		oobregion->length = (ecc->bytes * (ecc->steps - 1)) +
1725				    host->bbm_size;
1726		oobregion->offset = 0;
1727	} else {
1728		oobregion->length = host->ecc_bytes_hw + host->spare_bytes;
1729		oobregion->offset = mtd->oobsize - oobregion->length;
1730	}
1731
1732	return 0;
1733}
1734
1735static int qcom_nand_ooblayout_free(struct mtd_info *mtd, int section,
1736				     struct mtd_oob_region *oobregion)
1737{
1738	struct nand_chip *chip = mtd_to_nand(mtd);
1739	struct qcom_nand_host *host = to_qcom_nand_host(chip);
1740	struct nand_ecc_ctrl *ecc = &chip->ecc;
1741
1742	if (section)
1743		return -ERANGE;
1744
1745	oobregion->length = ecc->steps * 4;
1746	oobregion->offset = ((ecc->steps - 1) * ecc->bytes) + host->bbm_size;
1747
1748	return 0;
1749}
1750
1751static const struct mtd_ooblayout_ops qcom_nand_ooblayout_ops = {
1752	.ecc = qcom_nand_ooblayout_ecc,
1753	.free = qcom_nand_ooblayout_free,
1754};
1755
1756static int qcom_nand_host_setup(struct qcom_nand_host *host)
1757{
1758	struct nand_chip *chip = &host->chip;
1759	struct mtd_info *mtd = nand_to_mtd(chip);
1760	struct nand_ecc_ctrl *ecc = &chip->ecc;
1761	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
1762	int cwperpage, bad_block_byte;
1763	bool wide_bus;
1764	int ecc_mode = 1;
1765
1766	/*
1767	 * the controller requires each step consists of 512 bytes of data.
1768	 * bail out if DT has populated a wrong step size.
1769	 */
1770	if (ecc->size != NANDC_STEP_SIZE) {
1771		dev_err(nandc->dev, "invalid ecc size\n");
1772		return -EINVAL;
1773	}
1774
1775	wide_bus = chip->options & NAND_BUSWIDTH_16 ? true : false;
1776
1777	if (ecc->strength >= 8) {
1778		/* 8 bit ECC defaults to BCH ECC on all platforms */
1779		host->bch_enabled = true;
1780		ecc_mode = 1;
1781
1782		if (wide_bus) {
1783			host->ecc_bytes_hw = 14;
1784			host->spare_bytes = 0;
1785			host->bbm_size = 2;
1786		} else {
1787			host->ecc_bytes_hw = 13;
1788			host->spare_bytes = 2;
1789			host->bbm_size = 1;
1790		}
1791	} else {
1792		/*
1793		 * if the controller supports BCH for 4 bit ECC, the controller
1794		 * uses lesser bytes for ECC. If RS is used, the ECC bytes is
1795		 * always 10 bytes
1796		 */
1797		if (nandc->ecc_modes & ECC_BCH_4BIT) {
1798			/* BCH */
1799			host->bch_enabled = true;
1800			ecc_mode = 0;
1801
1802			if (wide_bus) {
1803				host->ecc_bytes_hw = 8;
1804				host->spare_bytes = 2;
1805				host->bbm_size = 2;
1806			} else {
1807				host->ecc_bytes_hw = 7;
1808				host->spare_bytes = 4;
1809				host->bbm_size = 1;
1810			}
1811		} else {
1812			/* RS */
1813			host->ecc_bytes_hw = 10;
1814
1815			if (wide_bus) {
1816				host->spare_bytes = 0;
1817				host->bbm_size = 2;
1818			} else {
1819				host->spare_bytes = 1;
1820				host->bbm_size = 1;
1821			}
1822		}
1823	}
1824
1825	/*
1826	 * we consider ecc->bytes as the sum of all the non-data content in a
1827	 * step. It gives us a clean representation of the oob area (even if
1828	 * all the bytes aren't used for ECC).It is always 16 bytes for 8 bit
1829	 * ECC and 12 bytes for 4 bit ECC
1830	 */
1831	ecc->bytes = host->ecc_bytes_hw + host->spare_bytes + host->bbm_size;
1832
1833	ecc->read_page		= qcom_nandc_read_page;
1834	ecc->read_page_raw	= qcom_nandc_read_page_raw;
1835	ecc->read_oob		= qcom_nandc_read_oob;
1836	ecc->write_page		= qcom_nandc_write_page;
1837	ecc->write_page_raw	= qcom_nandc_write_page_raw;
1838	ecc->write_oob		= qcom_nandc_write_oob;
1839
1840	ecc->mode = NAND_ECC_HW;
1841
1842	mtd_set_ooblayout(mtd, &qcom_nand_ooblayout_ops);
1843
1844	cwperpage = mtd->writesize / ecc->size;
1845
1846	/*
1847	 * DATA_UD_BYTES varies based on whether the read/write command protects
1848	 * spare data with ECC too. We protect spare data by default, so we set
1849	 * it to main + spare data, which are 512 and 4 bytes respectively.
1850	 */
1851	host->cw_data = 516;
1852
1853	/*
1854	 * total bytes in a step, either 528 bytes for 4 bit ECC, or 532 bytes
1855	 * for 8 bit ECC
1856	 */
1857	host->cw_size = host->cw_data + ecc->bytes;
1858
1859	if (ecc->bytes * (mtd->writesize / ecc->size) > mtd->oobsize) {
1860		dev_err(nandc->dev, "ecc data doesn't fit in OOB area\n");
1861		return -EINVAL;
1862	}
1863
1864	bad_block_byte = mtd->writesize - host->cw_size * (cwperpage - 1) + 1;
1865
1866	host->cfg0 = (cwperpage - 1) << CW_PER_PAGE
1867				| host->cw_data << UD_SIZE_BYTES
1868				| 0 << DISABLE_STATUS_AFTER_WRITE
1869				| 5 << NUM_ADDR_CYCLES
1870				| host->ecc_bytes_hw << ECC_PARITY_SIZE_BYTES_RS
1871				| 0 << STATUS_BFR_READ
1872				| 1 << SET_RD_MODE_AFTER_STATUS
1873				| host->spare_bytes << SPARE_SIZE_BYTES;
1874
1875	host->cfg1 = 7 << NAND_RECOVERY_CYCLES
1876				| 0 <<  CS_ACTIVE_BSY
1877				| bad_block_byte << BAD_BLOCK_BYTE_NUM
1878				| 0 << BAD_BLOCK_IN_SPARE_AREA
1879				| 2 << WR_RD_BSY_GAP
1880				| wide_bus << WIDE_FLASH
1881				| host->bch_enabled << ENABLE_BCH_ECC;
1882
1883	host->cfg0_raw = (cwperpage - 1) << CW_PER_PAGE
1884				| host->cw_size << UD_SIZE_BYTES
1885				| 5 << NUM_ADDR_CYCLES
1886				| 0 << SPARE_SIZE_BYTES;
1887
1888	host->cfg1_raw = 7 << NAND_RECOVERY_CYCLES
1889				| 0 << CS_ACTIVE_BSY
1890				| 17 << BAD_BLOCK_BYTE_NUM
1891				| 1 << BAD_BLOCK_IN_SPARE_AREA
1892				| 2 << WR_RD_BSY_GAP
1893				| wide_bus << WIDE_FLASH
1894				| 1 << DEV0_CFG1_ECC_DISABLE;
1895
1896	host->ecc_bch_cfg = host->bch_enabled << ECC_CFG_ECC_DISABLE
1897				| 0 << ECC_SW_RESET
1898				| host->cw_data << ECC_NUM_DATA_BYTES
1899				| 1 << ECC_FORCE_CLK_OPEN
1900				| ecc_mode << ECC_MODE
1901				| host->ecc_bytes_hw << ECC_PARITY_SIZE_BYTES_BCH;
1902
1903	host->ecc_buf_cfg = 0x203 << NUM_STEPS;
1904
1905	host->clrflashstatus = FS_READY_BSY_N;
1906	host->clrreadstatus = 0xc0;
1907
1908	dev_dbg(nandc->dev,
1909		"cfg0 %x cfg1 %x ecc_buf_cfg %x ecc_bch cfg %x cw_size %d cw_data %d strength %d parity_bytes %d steps %d\n",
1910		host->cfg0, host->cfg1, host->ecc_buf_cfg, host->ecc_bch_cfg,
1911		host->cw_size, host->cw_data, ecc->strength, ecc->bytes,
1912		cwperpage);
1913
1914	return 0;
1915}
1916
1917static int qcom_nandc_alloc(struct qcom_nand_controller *nandc)
1918{
1919	int ret;
1920
1921	ret = dma_set_coherent_mask(nandc->dev, DMA_BIT_MASK(32));
1922	if (ret) {
1923		dev_err(nandc->dev, "failed to set DMA mask\n");
1924		return ret;
1925	}
1926
1927	/*
1928	 * we use the internal buffer for reading ONFI params, reading small
1929	 * data like ID and status, and preforming read-copy-write operations
1930	 * when writing to a codeword partially. 532 is the maximum possible
1931	 * size of a codeword for our nand controller
1932	 */
1933	nandc->buf_size = 532;
1934
1935	nandc->data_buffer = devm_kzalloc(nandc->dev, nandc->buf_size,
1936					GFP_KERNEL);
1937	if (!nandc->data_buffer)
1938		return -ENOMEM;
1939
1940	nandc->regs = devm_kzalloc(nandc->dev, sizeof(*nandc->regs),
1941					GFP_KERNEL);
1942	if (!nandc->regs)
1943		return -ENOMEM;
1944
1945	nandc->reg_read_buf = devm_kzalloc(nandc->dev,
1946				MAX_REG_RD * sizeof(*nandc->reg_read_buf),
1947				GFP_KERNEL);
1948	if (!nandc->reg_read_buf)
1949		return -ENOMEM;
1950
1951	nandc->chan = dma_request_slave_channel(nandc->dev, "rxtx");
1952	if (!nandc->chan) {
1953		dev_err(nandc->dev, "failed to request slave channel\n");
1954		return -ENODEV;
1955	}
1956
1957	INIT_LIST_HEAD(&nandc->desc_list);
1958	INIT_LIST_HEAD(&nandc->host_list);
1959
1960	nand_hw_control_init(&nandc->controller);
1961
1962	return 0;
1963}
1964
1965static void qcom_nandc_unalloc(struct qcom_nand_controller *nandc)
1966{
1967	dma_release_channel(nandc->chan);
1968}
1969
1970/* one time setup of a few nand controller registers */
1971static int qcom_nandc_setup(struct qcom_nand_controller *nandc)
1972{
1973	/* kill onenand */
1974	nandc_write(nandc, SFLASHC_BURST_CFG, 0);
1975
1976	/* enable ADM DMA */
1977	nandc_write(nandc, NAND_FLASH_CHIP_SELECT, DM_EN);
1978
1979	/* save the original values of these registers */
1980	nandc->cmd1 = nandc_read(nandc, NAND_DEV_CMD1);
1981	nandc->vld = nandc_read(nandc, NAND_DEV_CMD_VLD);
1982
1983	return 0;
1984}
1985
1986static int qcom_nand_host_init(struct qcom_nand_controller *nandc,
1987			       struct qcom_nand_host *host,
1988			       struct device_node *dn)
1989{
1990	struct nand_chip *chip = &host->chip;
1991	struct mtd_info *mtd = nand_to_mtd(chip);
1992	struct device *dev = nandc->dev;
1993	int ret;
1994
1995	ret = of_property_read_u32(dn, "reg", &host->cs);
1996	if (ret) {
1997		dev_err(dev, "can't get chip-select\n");
1998		return -ENXIO;
1999	}
2000
2001	nand_set_flash_node(chip, dn);
2002	mtd->name = devm_kasprintf(dev, GFP_KERNEL, "qcom_nand.%d", host->cs);
2003	mtd->owner = THIS_MODULE;
2004	mtd->dev.parent = dev;
2005
2006	chip->cmdfunc		= qcom_nandc_command;
2007	chip->select_chip	= qcom_nandc_select_chip;
2008	chip->read_byte		= qcom_nandc_read_byte;
2009	chip->read_buf		= qcom_nandc_read_buf;
2010	chip->write_buf		= qcom_nandc_write_buf;
2011
2012	/*
2013	 * the bad block marker is readable only when we read the last codeword
2014	 * of a page with ECC disabled. currently, the nand_base and nand_bbt
2015	 * helpers don't allow us to read BB from a nand chip with ECC
2016	 * disabled (MTD_OPS_PLACE_OOB is set by default). use the block_bad
2017	 * and block_markbad helpers until we permanently switch to using
2018	 * MTD_OPS_RAW for all drivers (with the help of badblockbits)
2019	 */
2020	chip->block_bad		= qcom_nandc_block_bad;
2021	chip->block_markbad	= qcom_nandc_block_markbad;
2022
2023	chip->controller = &nandc->controller;
2024	chip->options |= NAND_NO_SUBPAGE_WRITE | NAND_USE_BOUNCE_BUFFER |
2025			 NAND_SKIP_BBTSCAN;
2026
2027	/* set up initial status value */
2028	host->status = NAND_STATUS_READY | NAND_STATUS_WP;
2029
2030	ret = nand_scan_ident(mtd, 1, NULL);
2031	if (ret)
2032		return ret;
2033
2034	ret = qcom_nand_host_setup(host);
2035	if (ret)
2036		return ret;
2037
2038	ret = nand_scan_tail(mtd);
2039	if (ret)
2040		return ret;
2041
2042	return mtd_device_register(mtd, NULL, 0);
2043}
2044
2045/* parse custom DT properties here */
2046static int qcom_nandc_parse_dt(struct platform_device *pdev)
2047{
2048	struct qcom_nand_controller *nandc = platform_get_drvdata(pdev);
2049	struct device_node *np = nandc->dev->of_node;
2050	int ret;
2051
2052	ret = of_property_read_u32(np, "qcom,cmd-crci", &nandc->cmd_crci);
2053	if (ret) {
2054		dev_err(nandc->dev, "command CRCI unspecified\n");
2055		return ret;
2056	}
2057
2058	ret = of_property_read_u32(np, "qcom,data-crci", &nandc->data_crci);
2059	if (ret) {
2060		dev_err(nandc->dev, "data CRCI unspecified\n");
2061		return ret;
2062	}
2063
2064	return 0;
2065}
2066
2067static int qcom_nandc_probe(struct platform_device *pdev)
2068{
2069	struct qcom_nand_controller *nandc;
2070	struct qcom_nand_host *host;
2071	const void *dev_data;
2072	struct device *dev = &pdev->dev;
2073	struct device_node *dn = dev->of_node, *child;
2074	struct resource *res;
2075	int ret;
2076
2077	nandc = devm_kzalloc(&pdev->dev, sizeof(*nandc), GFP_KERNEL);
2078	if (!nandc)
2079		return -ENOMEM;
2080
2081	platform_set_drvdata(pdev, nandc);
2082	nandc->dev = dev;
2083
2084	dev_data = of_device_get_match_data(dev);
2085	if (!dev_data) {
2086		dev_err(&pdev->dev, "failed to get device data\n");
2087		return -ENODEV;
2088	}
2089
2090	nandc->ecc_modes = (unsigned long)dev_data;
2091
2092	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
2093	nandc->base = devm_ioremap_resource(dev, res);
2094	if (IS_ERR(nandc->base))
2095		return PTR_ERR(nandc->base);
2096
2097	nandc->base_dma = phys_to_dma(dev, (phys_addr_t)res->start);
2098
2099	nandc->core_clk = devm_clk_get(dev, "core");
2100	if (IS_ERR(nandc->core_clk))
2101		return PTR_ERR(nandc->core_clk);
2102
2103	nandc->aon_clk = devm_clk_get(dev, "aon");
2104	if (IS_ERR(nandc->aon_clk))
2105		return PTR_ERR(nandc->aon_clk);
2106
2107	ret = qcom_nandc_parse_dt(pdev);
2108	if (ret)
2109		return ret;
2110
2111	ret = qcom_nandc_alloc(nandc);
2112	if (ret)
2113		return ret;
2114
2115	ret = clk_prepare_enable(nandc->core_clk);
2116	if (ret)
2117		goto err_core_clk;
2118
2119	ret = clk_prepare_enable(nandc->aon_clk);
2120	if (ret)
2121		goto err_aon_clk;
2122
2123	ret = qcom_nandc_setup(nandc);
2124	if (ret)
2125		goto err_setup;
2126
2127	for_each_available_child_of_node(dn, child) {
2128		if (of_device_is_compatible(child, "qcom,nandcs")) {
2129			host = devm_kzalloc(dev, sizeof(*host), GFP_KERNEL);
2130			if (!host) {
2131				of_node_put(child);
2132				ret = -ENOMEM;
2133				goto err_cs_init;
2134			}
2135
2136			ret = qcom_nand_host_init(nandc, host, child);
2137			if (ret) {
2138				devm_kfree(dev, host);
2139				continue;
2140			}
2141
2142			list_add_tail(&host->node, &nandc->host_list);
2143		}
2144	}
2145
2146	if (list_empty(&nandc->host_list)) {
2147		ret = -ENODEV;
2148		goto err_cs_init;
2149	}
2150
2151	return 0;
2152
2153err_cs_init:
2154	list_for_each_entry(host, &nandc->host_list, node)
2155		nand_release(nand_to_mtd(&host->chip));
2156err_setup:
2157	clk_disable_unprepare(nandc->aon_clk);
2158err_aon_clk:
2159	clk_disable_unprepare(nandc->core_clk);
2160err_core_clk:
2161	qcom_nandc_unalloc(nandc);
2162
2163	return ret;
2164}
2165
2166static int qcom_nandc_remove(struct platform_device *pdev)
2167{
2168	struct qcom_nand_controller *nandc = platform_get_drvdata(pdev);
2169	struct qcom_nand_host *host;
2170
2171	list_for_each_entry(host, &nandc->host_list, node)
2172		nand_release(nand_to_mtd(&host->chip));
2173
2174	qcom_nandc_unalloc(nandc);
2175
2176	clk_disable_unprepare(nandc->aon_clk);
2177	clk_disable_unprepare(nandc->core_clk);
2178
2179	return 0;
2180}
2181
2182#define EBI2_NANDC_ECC_MODES	(ECC_RS_4BIT | ECC_BCH_8BIT)
2183
2184/*
2185 * data will hold a struct pointer containing more differences once we support
2186 * more controller variants
2187 */
2188static const struct of_device_id qcom_nandc_of_match[] = {
2189	{	.compatible = "qcom,ipq806x-nand",
2190		.data = (void *)EBI2_NANDC_ECC_MODES,
2191	},
2192	{}
2193};
2194MODULE_DEVICE_TABLE(of, qcom_nandc_of_match);
2195
2196static struct platform_driver qcom_nandc_driver = {
2197	.driver = {
2198		.name = "qcom-nandc",
2199		.of_match_table = qcom_nandc_of_match,
2200	},
2201	.probe   = qcom_nandc_probe,
2202	.remove  = qcom_nandc_remove,
2203};
2204module_platform_driver(qcom_nandc_driver);
2205
2206MODULE_AUTHOR("Archit Taneja <architt@codeaurora.org>");
2207MODULE_DESCRIPTION("Qualcomm NAND Controller driver");
2208MODULE_LICENSE("GPL v2");