Linux Audio

Check our new training course

Embedded Linux Audio

Check our new training course
with Creative Commons CC-BY-SA
lecture materials

Bootlin logo

Elixir Cross Referencer

Loading...
   1
   2
   3
   4
   5
   6
   7
   8
   9
  10
  11
  12
  13
  14
  15
  16
  17
  18
  19
  20
  21
  22
  23
  24
  25
  26
  27
  28
  29
  30
  31
  32
  33
  34
  35
  36
  37
  38
  39
  40
  41
  42
  43
  44
  45
  46
  47
  48
  49
  50
  51
  52
  53
  54
  55
  56
  57
  58
  59
  60
  61
  62
  63
  64
  65
  66
  67
  68
  69
  70
  71
  72
  73
  74
  75
  76
  77
  78
  79
  80
  81
  82
  83
  84
  85
  86
  87
  88
  89
  90
  91
  92
  93
  94
  95
  96
  97
  98
  99
 100
 101
 102
 103
 104
 105
 106
 107
 108
 109
 110
 111
 112
 113
 114
 115
 116
 117
 118
 119
 120
 121
 122
 123
 124
 125
 126
 127
 128
 129
 130
 131
 132
 133
 134
 135
 136
 137
 138
 139
 140
 141
 142
 143
 144
 145
 146
 147
 148
 149
 150
 151
 152
 153
 154
 155
 156
 157
 158
 159
 160
 161
 162
 163
 164
 165
 166
 167
 168
 169
 170
 171
 172
 173
 174
 175
 176
 177
 178
 179
 180
 181
 182
 183
 184
 185
 186
 187
 188
 189
 190
 191
 192
 193
 194
 195
 196
 197
 198
 199
 200
 201
 202
 203
 204
 205
 206
 207
 208
 209
 210
 211
 212
 213
 214
 215
 216
 217
 218
 219
 220
 221
 222
 223
 224
 225
 226
 227
 228
 229
 230
 231
 232
 233
 234
 235
 236
 237
 238
 239
 240
 241
 242
 243
 244
 245
 246
 247
 248
 249
 250
 251
 252
 253
 254
 255
 256
 257
 258
 259
 260
 261
 262
 263
 264
 265
 266
 267
 268
 269
 270
 271
 272
 273
 274
 275
 276
 277
 278
 279
 280
 281
 282
 283
 284
 285
 286
 287
 288
 289
 290
 291
 292
 293
 294
 295
 296
 297
 298
 299
 300
 301
 302
 303
 304
 305
 306
 307
 308
 309
 310
 311
 312
 313
 314
 315
 316
 317
 318
 319
 320
 321
 322
 323
 324
 325
 326
 327
 328
 329
 330
 331
 332
 333
 334
 335
 336
 337
 338
 339
 340
 341
 342
 343
 344
 345
 346
 347
 348
 349
 350
 351
 352
 353
 354
 355
 356
 357
 358
 359
 360
 361
 362
 363
 364
 365
 366
 367
 368
 369
 370
 371
 372
 373
 374
 375
 376
 377
 378
 379
 380
 381
 382
 383
 384
 385
 386
 387
 388
 389
 390
 391
 392
 393
 394
 395
 396
 397
 398
 399
 400
 401
 402
 403
 404
 405
 406
 407
 408
 409
 410
 411
 412
 413
 414
 415
 416
 417
 418
 419
 420
 421
 422
 423
 424
 425
 426
 427
 428
 429
 430
 431
 432
 433
 434
 435
 436
 437
 438
 439
 440
 441
 442
 443
 444
 445
 446
 447
 448
 449
 450
 451
 452
 453
 454
 455
 456
 457
 458
 459
 460
 461
 462
 463
 464
 465
 466
 467
 468
 469
 470
 471
 472
 473
 474
 475
 476
 477
 478
 479
 480
 481
 482
 483
 484
 485
 486
 487
 488
 489
 490
 491
 492
 493
 494
 495
 496
 497
 498
 499
 500
 501
 502
 503
 504
 505
 506
 507
 508
 509
 510
 511
 512
 513
 514
 515
 516
 517
 518
 519
 520
 521
 522
 523
 524
 525
 526
 527
 528
 529
 530
 531
 532
 533
 534
 535
 536
 537
 538
 539
 540
 541
 542
 543
 544
 545
 546
 547
 548
 549
 550
 551
 552
 553
 554
 555
 556
 557
 558
 559
 560
 561
 562
 563
 564
 565
 566
 567
 568
 569
 570
 571
 572
 573
 574
 575
 576
 577
 578
 579
 580
 581
 582
 583
 584
 585
 586
 587
 588
 589
 590
 591
 592
 593
 594
 595
 596
 597
 598
 599
 600
 601
 602
 603
 604
 605
 606
 607
 608
 609
 610
 611
 612
 613
 614
 615
 616
 617
 618
 619
 620
 621
 622
 623
 624
 625
 626
 627
 628
 629
 630
 631
 632
 633
 634
 635
 636
 637
 638
 639
 640
 641
 642
 643
 644
 645
 646
 647
 648
 649
 650
 651
 652
 653
 654
 655
 656
 657
 658
 659
 660
 661
 662
 663
 664
 665
 666
 667
 668
 669
 670
 671
 672
 673
 674
 675
 676
 677
 678
 679
 680
 681
 682
 683
 684
 685
 686
 687
 688
 689
 690
 691
 692
 693
 694
 695
 696
 697
 698
 699
 700
 701
 702
 703
 704
 705
 706
 707
 708
 709
 710
 711
 712
 713
 714
 715
 716
 717
 718
 719
 720
 721
 722
 723
 724
 725
 726
 727
 728
 729
 730
 731
 732
 733
 734
 735
 736
 737
 738
 739
 740
 741
 742
 743
 744
 745
 746
 747
 748
 749
 750
 751
 752
 753
 754
 755
 756
 757
 758
 759
 760
 761
 762
 763
 764
 765
 766
 767
 768
 769
 770
 771
 772
 773
 774
 775
 776
 777
 778
 779
 780
 781
 782
 783
 784
 785
 786
 787
 788
 789
 790
 791
 792
 793
 794
 795
 796
 797
 798
 799
 800
 801
 802
 803
 804
 805
 806
 807
 808
 809
 810
 811
 812
 813
 814
 815
 816
 817
 818
 819
 820
 821
 822
 823
 824
 825
 826
 827
 828
 829
 830
 831
 832
 833
 834
 835
 836
 837
 838
 839
 840
 841
 842
 843
 844
 845
 846
 847
 848
 849
 850
 851
 852
 853
 854
 855
 856
 857
 858
 859
 860
 861
 862
 863
 864
 865
 866
 867
 868
 869
 870
 871
 872
 873
 874
 875
 876
 877
 878
 879
 880
 881
 882
 883
 884
 885
 886
 887
 888
 889
 890
 891
 892
 893
 894
 895
 896
 897
 898
 899
 900
 901
 902
 903
 904
 905
 906
 907
 908
 909
 910
 911
 912
 913
 914
 915
 916
 917
 918
 919
 920
 921
 922
 923
 924
 925
 926
 927
 928
 929
 930
 931
 932
 933
 934
 935
 936
 937
 938
 939
 940
 941
 942
 943
 944
 945
 946
 947
 948
 949
 950
 951
 952
 953
 954
 955
 956
 957
 958
 959
 960
 961
 962
 963
 964
 965
 966
 967
 968
 969
 970
 971
 972
 973
 974
 975
 976
 977
 978
 979
 980
 981
 982
 983
 984
 985
 986
 987
 988
 989
 990
 991
 992
 993
 994
 995
 996
 997
 998
 999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2015 MediaTek Inc.
 * Author: Leilk Liu <leilk.liu@mediatek.com>
 */

#include <linux/clk.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_gpio.h>
#include <linux/platform_device.h>
#include <linux/platform_data/spi-mt65xx.h>
#include <linux/pm_runtime.h>
#include <linux/spi/spi.h>
#include <linux/dma-mapping.h>

#define SPI_CFG0_REG                      0x0000
#define SPI_CFG1_REG                      0x0004
#define SPI_TX_SRC_REG                    0x0008
#define SPI_RX_DST_REG                    0x000c
#define SPI_TX_DATA_REG                   0x0010
#define SPI_RX_DATA_REG                   0x0014
#define SPI_CMD_REG                       0x0018
#define SPI_STATUS0_REG                   0x001c
#define SPI_PAD_SEL_REG                   0x0024
#define SPI_CFG2_REG                      0x0028
#define SPI_TX_SRC_REG_64                 0x002c
#define SPI_RX_DST_REG_64                 0x0030

#define SPI_CFG0_SCK_HIGH_OFFSET          0
#define SPI_CFG0_SCK_LOW_OFFSET           8
#define SPI_CFG0_CS_HOLD_OFFSET           16
#define SPI_CFG0_CS_SETUP_OFFSET          24
#define SPI_ADJUST_CFG0_CS_HOLD_OFFSET    0
#define SPI_ADJUST_CFG0_CS_SETUP_OFFSET   16

#define SPI_CFG1_CS_IDLE_OFFSET           0
#define SPI_CFG1_PACKET_LOOP_OFFSET       8
#define SPI_CFG1_PACKET_LENGTH_OFFSET     16
#define SPI_CFG1_GET_TICK_DLY_OFFSET      29
#define SPI_CFG1_GET_TICK_DLY_OFFSET_V1   30

#define SPI_CFG1_GET_TICK_DLY_MASK        0xe0000000
#define SPI_CFG1_GET_TICK_DLY_MASK_V1     0xc0000000

#define SPI_CFG1_CS_IDLE_MASK             0xff
#define SPI_CFG1_PACKET_LOOP_MASK         0xff00
#define SPI_CFG1_PACKET_LENGTH_MASK       0x3ff0000
#define SPI_CFG2_SCK_HIGH_OFFSET          0
#define SPI_CFG2_SCK_LOW_OFFSET           16

#define SPI_CMD_ACT                  BIT(0)
#define SPI_CMD_RESUME               BIT(1)
#define SPI_CMD_RST                  BIT(2)
#define SPI_CMD_PAUSE_EN             BIT(4)
#define SPI_CMD_DEASSERT             BIT(5)
#define SPI_CMD_SAMPLE_SEL           BIT(6)
#define SPI_CMD_CS_POL               BIT(7)
#define SPI_CMD_CPHA                 BIT(8)
#define SPI_CMD_CPOL                 BIT(9)
#define SPI_CMD_RX_DMA               BIT(10)
#define SPI_CMD_TX_DMA               BIT(11)
#define SPI_CMD_TXMSBF               BIT(12)
#define SPI_CMD_RXMSBF               BIT(13)
#define SPI_CMD_RX_ENDIAN            BIT(14)
#define SPI_CMD_TX_ENDIAN            BIT(15)
#define SPI_CMD_FINISH_IE            BIT(16)
#define SPI_CMD_PAUSE_IE             BIT(17)

#define MT8173_SPI_MAX_PAD_SEL 3

#define MTK_SPI_PAUSE_INT_STATUS 0x2

#define MTK_SPI_IDLE 0
#define MTK_SPI_PAUSED 1

#define MTK_SPI_MAX_FIFO_SIZE 32U
#define MTK_SPI_PACKET_SIZE 1024
#define MTK_SPI_32BITS_MASK  (0xffffffff)

#define DMA_ADDR_EXT_BITS (36)
#define DMA_ADDR_DEF_BITS (32)

struct mtk_spi_compatible {
	bool need_pad_sel;
	/* Must explicitly send dummy Tx bytes to do Rx only transfer */
	bool must_tx;
	/* some IC design adjust cfg register to enhance time accuracy */
	bool enhance_timing;
	/* some IC support DMA addr extension */
	bool dma_ext;
	/* some IC no need unprepare SPI clk */
	bool no_need_unprepare;
};

struct mtk_spi {
	void __iomem *base;
	u32 state;
	int pad_num;
	u32 *pad_sel;
	struct clk *parent_clk, *sel_clk, *spi_clk;
	struct spi_transfer *cur_transfer;
	u32 xfer_len;
	u32 num_xfered;
	struct scatterlist *tx_sgl, *rx_sgl;
	u32 tx_sgl_len, rx_sgl_len;
	const struct mtk_spi_compatible *dev_comp;
	u32 spi_clk_hz;
};

static const struct mtk_spi_compatible mtk_common_compat;

static const struct mtk_spi_compatible mt2712_compat = {
	.must_tx = true,
};

static const struct mtk_spi_compatible mt6765_compat = {
	.need_pad_sel = true,
	.must_tx = true,
	.enhance_timing = true,
	.dma_ext = true,
};

static const struct mtk_spi_compatible mt7622_compat = {
	.must_tx = true,
	.enhance_timing = true,
};

static const struct mtk_spi_compatible mt8173_compat = {
	.need_pad_sel = true,
	.must_tx = true,
};

static const struct mtk_spi_compatible mt8183_compat = {
	.need_pad_sel = true,
	.must_tx = true,
	.enhance_timing = true,
};

static const struct mtk_spi_compatible mt6893_compat = {
	.need_pad_sel = true,
	.must_tx = true,
	.enhance_timing = true,
	.dma_ext = true,
	.no_need_unprepare = true,
};

/*
 * A piece of default chip info unless the platform
 * supplies it.
 */
static const struct mtk_chip_config mtk_default_chip_info = {
	.sample_sel = 0,
	.tick_delay = 0,
};

static const struct of_device_id mtk_spi_of_match[] = {
	{ .compatible = "mediatek,mt2701-spi",
		.data = (void *)&mtk_common_compat,
	},
	{ .compatible = "mediatek,mt2712-spi",
		.data = (void *)&mt2712_compat,
	},
	{ .compatible = "mediatek,mt6589-spi",
		.data = (void *)&mtk_common_compat,
	},
	{ .compatible = "mediatek,mt6765-spi",
		.data = (void *)&mt6765_compat,
	},
	{ .compatible = "mediatek,mt7622-spi",
		.data = (void *)&mt7622_compat,
	},
	{ .compatible = "mediatek,mt7629-spi",
		.data = (void *)&mt7622_compat,
	},
	{ .compatible = "mediatek,mt8135-spi",
		.data = (void *)&mtk_common_compat,
	},
	{ .compatible = "mediatek,mt8173-spi",
		.data = (void *)&mt8173_compat,
	},
	{ .compatible = "mediatek,mt8183-spi",
		.data = (void *)&mt8183_compat,
	},
	{ .compatible = "mediatek,mt8192-spi",
		.data = (void *)&mt6765_compat,
	},
	{ .compatible = "mediatek,mt6893-spi",
		.data = (void *)&mt6893_compat,
	},
	{}
};
MODULE_DEVICE_TABLE(of, mtk_spi_of_match);

static void mtk_spi_reset(struct mtk_spi *mdata)
{
	u32 reg_val;

	/* set the software reset bit in SPI_CMD_REG. */
	reg_val = readl(mdata->base + SPI_CMD_REG);
	reg_val |= SPI_CMD_RST;
	writel(reg_val, mdata->base + SPI_CMD_REG);

	reg_val = readl(mdata->base + SPI_CMD_REG);
	reg_val &= ~SPI_CMD_RST;
	writel(reg_val, mdata->base + SPI_CMD_REG);
}

static int mtk_spi_set_hw_cs_timing(struct spi_device *spi)
{
	struct mtk_spi *mdata = spi_master_get_devdata(spi->master);
	struct spi_delay *cs_setup = &spi->cs_setup;
	struct spi_delay *cs_hold = &spi->cs_hold;
	struct spi_delay *cs_inactive = &spi->cs_inactive;
	u32 setup, hold, inactive;
	u32 reg_val;
	int delay;

	delay = spi_delay_to_ns(cs_setup, NULL);
	if (delay < 0)
		return delay;
	setup = (delay * DIV_ROUND_UP(mdata->spi_clk_hz, 1000000)) / 1000;

	delay = spi_delay_to_ns(cs_hold, NULL);
	if (delay < 0)
		return delay;
	hold = (delay * DIV_ROUND_UP(mdata->spi_clk_hz, 1000000)) / 1000;

	delay = spi_delay_to_ns(cs_inactive, NULL);
	if (delay < 0)
		return delay;
	inactive = (delay * DIV_ROUND_UP(mdata->spi_clk_hz, 1000000)) / 1000;

	if (hold || setup) {
		reg_val = readl(mdata->base + SPI_CFG0_REG);
		if (mdata->dev_comp->enhance_timing) {
			if (hold) {
				hold = min_t(u32, hold, 0x10000);
				reg_val &= ~(0xffff << SPI_ADJUST_CFG0_CS_HOLD_OFFSET);
				reg_val |= (((hold - 1) & 0xffff)
					<< SPI_ADJUST_CFG0_CS_HOLD_OFFSET);
			}
			if (setup) {
				setup = min_t(u32, setup, 0x10000);
				reg_val &= ~(0xffff << SPI_ADJUST_CFG0_CS_SETUP_OFFSET);
				reg_val |= (((setup - 1) & 0xffff)
					<< SPI_ADJUST_CFG0_CS_SETUP_OFFSET);
			}
		} else {
			if (hold) {
				hold = min_t(u32, hold, 0x100);
				reg_val &= ~(0xff << SPI_CFG0_CS_HOLD_OFFSET);
				reg_val |= (((hold - 1) & 0xff) << SPI_CFG0_CS_HOLD_OFFSET);
			}
			if (setup) {
				setup = min_t(u32, setup, 0x100);
				reg_val &= ~(0xff << SPI_CFG0_CS_SETUP_OFFSET);
				reg_val |= (((setup - 1) & 0xff)
					<< SPI_CFG0_CS_SETUP_OFFSET);
			}
		}
		writel(reg_val, mdata->base + SPI_CFG0_REG);
	}

	if (inactive) {
		inactive = min_t(u32, inactive, 0x100);
		reg_val = readl(mdata->base + SPI_CFG1_REG);
		reg_val &= ~SPI_CFG1_CS_IDLE_MASK;
		reg_val |= (((inactive - 1) & 0xff) << SPI_CFG1_CS_IDLE_OFFSET);
		writel(reg_val, mdata->base + SPI_CFG1_REG);
	}

	return 0;
}

static int mtk_spi_prepare_message(struct spi_master *master,
				   struct spi_message *msg)
{
	u16 cpha, cpol;
	u32 reg_val;
	struct spi_device *spi = msg->spi;
	struct mtk_chip_config *chip_config = spi->controller_data;
	struct mtk_spi *mdata = spi_master_get_devdata(master);

	cpha = spi->mode & SPI_CPHA ? 1 : 0;
	cpol = spi->mode & SPI_CPOL ? 1 : 0;

	reg_val = readl(mdata->base + SPI_CMD_REG);
	if (cpha)
		reg_val |= SPI_CMD_CPHA;
	else
		reg_val &= ~SPI_CMD_CPHA;
	if (cpol)
		reg_val |= SPI_CMD_CPOL;
	else
		reg_val &= ~SPI_CMD_CPOL;

	/* set the mlsbx and mlsbtx */
	if (spi->mode & SPI_LSB_FIRST) {
		reg_val &= ~SPI_CMD_TXMSBF;
		reg_val &= ~SPI_CMD_RXMSBF;
	} else {
		reg_val |= SPI_CMD_TXMSBF;
		reg_val |= SPI_CMD_RXMSBF;
	}

	/* set the tx/rx endian */
#ifdef __LITTLE_ENDIAN
	reg_val &= ~SPI_CMD_TX_ENDIAN;
	reg_val &= ~SPI_CMD_RX_ENDIAN;
#else
	reg_val |= SPI_CMD_TX_ENDIAN;
	reg_val |= SPI_CMD_RX_ENDIAN;
#endif

	if (mdata->dev_comp->enhance_timing) {
		/* set CS polarity */
		if (spi->mode & SPI_CS_HIGH)
			reg_val |= SPI_CMD_CS_POL;
		else
			reg_val &= ~SPI_CMD_CS_POL;

		if (chip_config->sample_sel)
			reg_val |= SPI_CMD_SAMPLE_SEL;
		else
			reg_val &= ~SPI_CMD_SAMPLE_SEL;
	}

	/* set finish and pause interrupt always enable */
	reg_val |= SPI_CMD_FINISH_IE | SPI_CMD_PAUSE_IE;

	/* disable dma mode */
	reg_val &= ~(SPI_CMD_TX_DMA | SPI_CMD_RX_DMA);

	/* disable deassert mode */
	reg_val &= ~SPI_CMD_DEASSERT;

	writel(reg_val, mdata->base + SPI_CMD_REG);

	/* pad select */
	if (mdata->dev_comp->need_pad_sel)
		writel(mdata->pad_sel[spi->chip_select],
		       mdata->base + SPI_PAD_SEL_REG);

	/* tick delay */
	reg_val = readl(mdata->base + SPI_CFG1_REG);
	if (mdata->dev_comp->enhance_timing) {
		reg_val &= ~SPI_CFG1_GET_TICK_DLY_MASK;
		reg_val |= ((chip_config->tick_delay & 0x7)
			    << SPI_CFG1_GET_TICK_DLY_OFFSET);
	} else {
		reg_val &= ~SPI_CFG1_GET_TICK_DLY_MASK_V1;
		reg_val |= ((chip_config->tick_delay & 0x3)
			    << SPI_CFG1_GET_TICK_DLY_OFFSET_V1);
	}
	writel(reg_val, mdata->base + SPI_CFG1_REG);

	/* set hw cs timing */
	mtk_spi_set_hw_cs_timing(spi);
	return 0;
}

static void mtk_spi_set_cs(struct spi_device *spi, bool enable)
{
	u32 reg_val;
	struct mtk_spi *mdata = spi_master_get_devdata(spi->master);

	if (spi->mode & SPI_CS_HIGH)
		enable = !enable;

	reg_val = readl(mdata->base + SPI_CMD_REG);
	if (!enable) {
		reg_val |= SPI_CMD_PAUSE_EN;
		writel(reg_val, mdata->base + SPI_CMD_REG);
	} else {
		reg_val &= ~SPI_CMD_PAUSE_EN;
		writel(reg_val, mdata->base + SPI_CMD_REG);
		mdata->state = MTK_SPI_IDLE;
		mtk_spi_reset(mdata);
	}
}

static void mtk_spi_prepare_transfer(struct spi_master *master,
				     struct spi_transfer *xfer)
{
	u32 div, sck_time, reg_val;
	struct mtk_spi *mdata = spi_master_get_devdata(master);

	if (xfer->speed_hz < mdata->spi_clk_hz / 2)
		div = DIV_ROUND_UP(mdata->spi_clk_hz, xfer->speed_hz);
	else
		div = 1;

	sck_time = (div + 1) / 2;

	if (mdata->dev_comp->enhance_timing) {
		reg_val = readl(mdata->base + SPI_CFG2_REG);
		reg_val &= ~(0xffff << SPI_CFG2_SCK_HIGH_OFFSET);
		reg_val |= (((sck_time - 1) & 0xffff)
			   << SPI_CFG2_SCK_HIGH_OFFSET);
		reg_val &= ~(0xffff << SPI_CFG2_SCK_LOW_OFFSET);
		reg_val |= (((sck_time - 1) & 0xffff)
			   << SPI_CFG2_SCK_LOW_OFFSET);
		writel(reg_val, mdata->base + SPI_CFG2_REG);
	} else {
		reg_val = readl(mdata->base + SPI_CFG0_REG);
		reg_val &= ~(0xff << SPI_CFG0_SCK_HIGH_OFFSET);
		reg_val |= (((sck_time - 1) & 0xff)
			   << SPI_CFG0_SCK_HIGH_OFFSET);
		reg_val &= ~(0xff << SPI_CFG0_SCK_LOW_OFFSET);
		reg_val |= (((sck_time - 1) & 0xff) << SPI_CFG0_SCK_LOW_OFFSET);
		writel(reg_val, mdata->base + SPI_CFG0_REG);
	}
}

static void mtk_spi_setup_packet(struct spi_master *master)
{
	u32 packet_size, packet_loop, reg_val;
	struct mtk_spi *mdata = spi_master_get_devdata(master);

	packet_size = min_t(u32, mdata->xfer_len, MTK_SPI_PACKET_SIZE);
	packet_loop = mdata->xfer_len / packet_size;

	reg_val = readl(mdata->base + SPI_CFG1_REG);
	reg_val &= ~(SPI_CFG1_PACKET_LENGTH_MASK | SPI_CFG1_PACKET_LOOP_MASK);
	reg_val |= (packet_size - 1) << SPI_CFG1_PACKET_LENGTH_OFFSET;
	reg_val |= (packet_loop - 1) << SPI_CFG1_PACKET_LOOP_OFFSET;
	writel(reg_val, mdata->base + SPI_CFG1_REG);
}

static void mtk_spi_enable_transfer(struct spi_master *master)
{
	u32 cmd;
	struct mtk_spi *mdata = spi_master_get_devdata(master);

	cmd = readl(mdata->base + SPI_CMD_REG);
	if (mdata->state == MTK_SPI_IDLE)
		cmd |= SPI_CMD_ACT;
	else
		cmd |= SPI_CMD_RESUME;
	writel(cmd, mdata->base + SPI_CMD_REG);
}

static int mtk_spi_get_mult_delta(u32 xfer_len)
{
	u32 mult_delta;

	if (xfer_len > MTK_SPI_PACKET_SIZE)
		mult_delta = xfer_len % MTK_SPI_PACKET_SIZE;
	else
		mult_delta = 0;

	return mult_delta;
}

static void mtk_spi_update_mdata_len(struct spi_master *master)
{
	int mult_delta;
	struct mtk_spi *mdata = spi_master_get_devdata(master);

	if (mdata->tx_sgl_len && mdata->rx_sgl_len) {
		if (mdata->tx_sgl_len > mdata->rx_sgl_len) {
			mult_delta = mtk_spi_get_mult_delta(mdata->rx_sgl_len);
			mdata->xfer_len = mdata->rx_sgl_len - mult_delta;
			mdata->rx_sgl_len = mult_delta;
			mdata->tx_sgl_len -= mdata->xfer_len;
		} else {
			mult_delta = mtk_spi_get_mult_delta(mdata->tx_sgl_len);
			mdata->xfer_len = mdata->tx_sgl_len - mult_delta;
			mdata->tx_sgl_len = mult_delta;
			mdata->rx_sgl_len -= mdata->xfer_len;
		}
	} else if (mdata->tx_sgl_len) {
		mult_delta = mtk_spi_get_mult_delta(mdata->tx_sgl_len);
		mdata->xfer_len = mdata->tx_sgl_len - mult_delta;
		mdata->tx_sgl_len = mult_delta;
	} else if (mdata->rx_sgl_len) {
		mult_delta = mtk_spi_get_mult_delta(mdata->rx_sgl_len);
		mdata->xfer_len = mdata->rx_sgl_len - mult_delta;
		mdata->rx_sgl_len = mult_delta;
	}
}

static void mtk_spi_setup_dma_addr(struct spi_master *master,
				   struct spi_transfer *xfer)
{
	struct mtk_spi *mdata = spi_master_get_devdata(master);

	if (mdata->tx_sgl) {
		writel((u32)(xfer->tx_dma & MTK_SPI_32BITS_MASK),
		       mdata->base + SPI_TX_SRC_REG);
#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
		if (mdata->dev_comp->dma_ext)
			writel((u32)(xfer->tx_dma >> 32),
			       mdata->base + SPI_TX_SRC_REG_64);
#endif
	}

	if (mdata->rx_sgl) {
		writel((u32)(xfer->rx_dma & MTK_SPI_32BITS_MASK),
		       mdata->base + SPI_RX_DST_REG);
#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
		if (mdata->dev_comp->dma_ext)
			writel((u32)(xfer->rx_dma >> 32),
			       mdata->base + SPI_RX_DST_REG_64);
#endif
	}
}

static int mtk_spi_fifo_transfer(struct spi_master *master,
				 struct spi_device *spi,
				 struct spi_transfer *xfer)
{
	int cnt, remainder;
	u32 reg_val;
	struct mtk_spi *mdata = spi_master_get_devdata(master);

	mdata->cur_transfer = xfer;
	mdata->xfer_len = min(MTK_SPI_MAX_FIFO_SIZE, xfer->len);
	mdata->num_xfered = 0;
	mtk_spi_prepare_transfer(master, xfer);
	mtk_spi_setup_packet(master);

	if (xfer->tx_buf) {
		cnt = xfer->len / 4;
		iowrite32_rep(mdata->base + SPI_TX_DATA_REG, xfer->tx_buf, cnt);
		remainder = xfer->len % 4;
		if (remainder > 0) {
			reg_val = 0;
			memcpy(&reg_val, xfer->tx_buf + (cnt * 4), remainder);
			writel(reg_val, mdata->base + SPI_TX_DATA_REG);
		}
	}

	mtk_spi_enable_transfer(master);

	return 1;
}

static int mtk_spi_dma_transfer(struct spi_master *master,
				struct spi_device *spi,
				struct spi_transfer *xfer)
{
	int cmd;
	struct mtk_spi *mdata = spi_master_get_devdata(master);

	mdata->tx_sgl = NULL;
	mdata->rx_sgl = NULL;
	mdata->tx_sgl_len = 0;
	mdata->rx_sgl_len = 0;
	mdata->cur_transfer = xfer;
	mdata->num_xfered = 0;

	mtk_spi_prepare_transfer(master, xfer);

	cmd = readl(mdata->base + SPI_CMD_REG);
	if (xfer->tx_buf)
		cmd |= SPI_CMD_TX_DMA;
	if (xfer->rx_buf)
		cmd |= SPI_CMD_RX_DMA;
	writel(cmd, mdata->base + SPI_CMD_REG);

	if (xfer->tx_buf)
		mdata->tx_sgl = xfer->tx_sg.sgl;
	if (xfer->rx_buf)
		mdata->rx_sgl = xfer->rx_sg.sgl;

	if (mdata->tx_sgl) {
		xfer->tx_dma = sg_dma_address(mdata->tx_sgl);
		mdata->tx_sgl_len = sg_dma_len(mdata->tx_sgl);
	}
	if (mdata->rx_sgl) {
		xfer->rx_dma = sg_dma_address(mdata->rx_sgl);
		mdata->rx_sgl_len = sg_dma_len(mdata->rx_sgl);
	}

	mtk_spi_update_mdata_len(master);
	mtk_spi_setup_packet(master);
	mtk_spi_setup_dma_addr(master, xfer);
	mtk_spi_enable_transfer(master);

	return 1;
}

static int mtk_spi_transfer_one(struct spi_master *master,
				struct spi_device *spi,
				struct spi_transfer *xfer)
{
	if (master->can_dma(master, spi, xfer))
		return mtk_spi_dma_transfer(master, spi, xfer);
	else
		return mtk_spi_fifo_transfer(master, spi, xfer);
}

static bool mtk_spi_can_dma(struct spi_master *master,
			    struct spi_device *spi,
			    struct spi_transfer *xfer)
{
	/* Buffers for DMA transactions must be 4-byte aligned */
	return (xfer->len > MTK_SPI_MAX_FIFO_SIZE &&
		(unsigned long)xfer->tx_buf % 4 == 0 &&
		(unsigned long)xfer->rx_buf % 4 == 0);
}

static int mtk_spi_setup(struct spi_device *spi)
{
	struct mtk_spi *mdata = spi_master_get_devdata(spi->master);

	if (!spi->controller_data)
		spi->controller_data = (void *)&mtk_default_chip_info;

	if (mdata->dev_comp->need_pad_sel && gpio_is_valid(spi->cs_gpio))
		gpio_direction_output(spi->cs_gpio, !(spi->mode & SPI_CS_HIGH));

	return 0;
}

static irqreturn_t mtk_spi_interrupt(int irq, void *dev_id)
{
	u32 cmd, reg_val, cnt, remainder, len;
	struct spi_master *master = dev_id;
	struct mtk_spi *mdata = spi_master_get_devdata(master);
	struct spi_transfer *trans = mdata->cur_transfer;

	reg_val = readl(mdata->base + SPI_STATUS0_REG);
	if (reg_val & MTK_SPI_PAUSE_INT_STATUS)
		mdata->state = MTK_SPI_PAUSED;
	else
		mdata->state = MTK_SPI_IDLE;

	if (!master->can_dma(master, NULL, trans)) {
		if (trans->rx_buf) {
			cnt = mdata->xfer_len / 4;
			ioread32_rep(mdata->base + SPI_RX_DATA_REG,
				     trans->rx_buf + mdata->num_xfered, cnt);
			remainder = mdata->xfer_len % 4;
			if (remainder > 0) {
				reg_val = readl(mdata->base + SPI_RX_DATA_REG);
				memcpy(trans->rx_buf +
					mdata->num_xfered +
					(cnt * 4),
					&reg_val,
					remainder);
			}
		}

		mdata->num_xfered += mdata->xfer_len;
		if (mdata->num_xfered == trans->len) {
			spi_finalize_current_transfer(master);
			return IRQ_HANDLED;
		}

		len = trans->len - mdata->num_xfered;
		mdata->xfer_len = min(MTK_SPI_MAX_FIFO_SIZE, len);
		mtk_spi_setup_packet(master);

		cnt = mdata->xfer_len / 4;
		iowrite32_rep(mdata->base + SPI_TX_DATA_REG,
				trans->tx_buf + mdata->num_xfered, cnt);

		remainder = mdata->xfer_len % 4;
		if (remainder > 0) {
			reg_val = 0;
			memcpy(&reg_val,
				trans->tx_buf + (cnt * 4) + mdata->num_xfered,
				remainder);
			writel(reg_val, mdata->base + SPI_TX_DATA_REG);
		}

		mtk_spi_enable_transfer(master);

		return IRQ_HANDLED;
	}

	if (mdata->tx_sgl)
		trans->tx_dma += mdata->xfer_len;
	if (mdata->rx_sgl)
		trans->rx_dma += mdata->xfer_len;

	if (mdata->tx_sgl && (mdata->tx_sgl_len == 0)) {
		mdata->tx_sgl = sg_next(mdata->tx_sgl);
		if (mdata->tx_sgl) {
			trans->tx_dma = sg_dma_address(mdata->tx_sgl);
			mdata->tx_sgl_len = sg_dma_len(mdata->tx_sgl);
		}
	}
	if (mdata->rx_sgl && (mdata->rx_sgl_len == 0)) {
		mdata->rx_sgl = sg_next(mdata->rx_sgl);
		if (mdata->rx_sgl) {
			trans->rx_dma = sg_dma_address(mdata->rx_sgl);
			mdata->rx_sgl_len = sg_dma_len(mdata->rx_sgl);
		}
	}

	if (!mdata->tx_sgl && !mdata->rx_sgl) {
		/* spi disable dma */
		cmd = readl(mdata->base + SPI_CMD_REG);
		cmd &= ~SPI_CMD_TX_DMA;
		cmd &= ~SPI_CMD_RX_DMA;
		writel(cmd, mdata->base + SPI_CMD_REG);

		spi_finalize_current_transfer(master);
		return IRQ_HANDLED;
	}

	mtk_spi_update_mdata_len(master);
	mtk_spi_setup_packet(master);
	mtk_spi_setup_dma_addr(master, trans);
	mtk_spi_enable_transfer(master);

	return IRQ_HANDLED;
}

static int mtk_spi_probe(struct platform_device *pdev)
{
	struct spi_master *master;
	struct mtk_spi *mdata;
	const struct of_device_id *of_id;
	int i, irq, ret, addr_bits;

	master = spi_alloc_master(&pdev->dev, sizeof(*mdata));
	if (!master) {
		dev_err(&pdev->dev, "failed to alloc spi master\n");
		return -ENOMEM;
	}

	master->auto_runtime_pm = true;
	master->dev.of_node = pdev->dev.of_node;
	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST;

	master->set_cs = mtk_spi_set_cs;
	master->prepare_message = mtk_spi_prepare_message;
	master->transfer_one = mtk_spi_transfer_one;
	master->can_dma = mtk_spi_can_dma;
	master->setup = mtk_spi_setup;
	master->set_cs_timing = mtk_spi_set_hw_cs_timing;

	of_id = of_match_node(mtk_spi_of_match, pdev->dev.of_node);
	if (!of_id) {
		dev_err(&pdev->dev, "failed to probe of_node\n");
		ret = -EINVAL;
		goto err_put_master;
	}

	mdata = spi_master_get_devdata(master);
	mdata->dev_comp = of_id->data;

	if (mdata->dev_comp->enhance_timing)
		master->mode_bits |= SPI_CS_HIGH;

	if (mdata->dev_comp->must_tx)
		master->flags = SPI_MASTER_MUST_TX;

	if (mdata->dev_comp->need_pad_sel) {
		mdata->pad_num = of_property_count_u32_elems(
			pdev->dev.of_node,
			"mediatek,pad-select");
		if (mdata->pad_num < 0) {
			dev_err(&pdev->dev,
				"No 'mediatek,pad-select' property\n");
			ret = -EINVAL;
			goto err_put_master;
		}

		mdata->pad_sel = devm_kmalloc_array(&pdev->dev, mdata->pad_num,
						    sizeof(u32), GFP_KERNEL);
		if (!mdata->pad_sel) {
			ret = -ENOMEM;
			goto err_put_master;
		}

		for (i = 0; i < mdata->pad_num; i++) {
			of_property_read_u32_index(pdev->dev.of_node,
						   "mediatek,pad-select",
						   i, &mdata->pad_sel[i]);
			if (mdata->pad_sel[i] > MT8173_SPI_MAX_PAD_SEL) {
				dev_err(&pdev->dev, "wrong pad-sel[%d]: %u\n",
					i, mdata->pad_sel[i]);
				ret = -EINVAL;
				goto err_put_master;
			}
		}
	}

	platform_set_drvdata(pdev, master);
	mdata->base = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(mdata->base)) {
		ret = PTR_ERR(mdata->base);
		goto err_put_master;
	}

	irq = platform_get_irq(pdev, 0);
	if (irq < 0) {
		ret = irq;
		goto err_put_master;
	}

	if (!pdev->dev.dma_mask)
		pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;

	ret = devm_request_irq(&pdev->dev, irq, mtk_spi_interrupt,
			       IRQF_TRIGGER_NONE, dev_name(&pdev->dev), master);
	if (ret) {
		dev_err(&pdev->dev, "failed to register irq (%d)\n", ret);
		goto err_put_master;
	}

	mdata->parent_clk = devm_clk_get(&pdev->dev, "parent-clk");
	if (IS_ERR(mdata->parent_clk)) {
		ret = PTR_ERR(mdata->parent_clk);
		dev_err(&pdev->dev, "failed to get parent-clk: %d\n", ret);
		goto err_put_master;
	}

	mdata->sel_clk = devm_clk_get(&pdev->dev, "sel-clk");
	if (IS_ERR(mdata->sel_clk)) {
		ret = PTR_ERR(mdata->sel_clk);
		dev_err(&pdev->dev, "failed to get sel-clk: %d\n", ret);
		goto err_put_master;
	}

	mdata->spi_clk = devm_clk_get(&pdev->dev, "spi-clk");
	if (IS_ERR(mdata->spi_clk)) {
		ret = PTR_ERR(mdata->spi_clk);
		dev_err(&pdev->dev, "failed to get spi-clk: %d\n", ret);
		goto err_put_master;
	}

	ret = clk_prepare_enable(mdata->spi_clk);
	if (ret < 0) {
		dev_err(&pdev->dev, "failed to enable spi_clk (%d)\n", ret);
		goto err_put_master;
	}

	ret = clk_set_parent(mdata->sel_clk, mdata->parent_clk);
	if (ret < 0) {
		dev_err(&pdev->dev, "failed to clk_set_parent (%d)\n", ret);
		clk_disable_unprepare(mdata->spi_clk);
		goto err_put_master;
	}

	mdata->spi_clk_hz = clk_get_rate(mdata->spi_clk);

	if (mdata->dev_comp->no_need_unprepare)
		clk_disable(mdata->spi_clk);
	else
		clk_disable_unprepare(mdata->spi_clk);

	pm_runtime_enable(&pdev->dev);

	if (mdata->dev_comp->need_pad_sel) {
		if (mdata->pad_num != master->num_chipselect) {
			dev_err(&pdev->dev,
				"pad_num does not match num_chipselect(%d != %d)\n",
				mdata->pad_num, master->num_chipselect);
			ret = -EINVAL;
			goto err_disable_runtime_pm;
		}

		if (!master->cs_gpios && master->num_chipselect > 1) {
			dev_err(&pdev->dev,
				"cs_gpios not specified and num_chipselect > 1\n");
			ret = -EINVAL;
			goto err_disable_runtime_pm;
		}

		if (master->cs_gpios) {
			for (i = 0; i < master->num_chipselect; i++) {
				ret = devm_gpio_request(&pdev->dev,
							master->cs_gpios[i],
							dev_name(&pdev->dev));
				if (ret) {
					dev_err(&pdev->dev,
						"can't get CS GPIO %i\n", i);
					goto err_disable_runtime_pm;
				}
			}
		}
	}

	if (mdata->dev_comp->dma_ext)
		addr_bits = DMA_ADDR_EXT_BITS;
	else
		addr_bits = DMA_ADDR_DEF_BITS;
	ret = dma_set_mask(&pdev->dev, DMA_BIT_MASK(addr_bits));
	if (ret)
		dev_notice(&pdev->dev, "SPI dma_set_mask(%d) failed, ret:%d\n",
			   addr_bits, ret);

	ret = devm_spi_register_master(&pdev->dev, master);
	if (ret) {
		dev_err(&pdev->dev, "failed to register master (%d)\n", ret);
		goto err_disable_runtime_pm;
	}

	return 0;

err_disable_runtime_pm:
	pm_runtime_disable(&pdev->dev);
err_put_master:
	spi_master_put(master);

	return ret;
}

static int mtk_spi_remove(struct platform_device *pdev)
{
	struct spi_master *master = platform_get_drvdata(pdev);
	struct mtk_spi *mdata = spi_master_get_devdata(master);

	pm_runtime_disable(&pdev->dev);

	mtk_spi_reset(mdata);

	if (mdata->dev_comp->no_need_unprepare)
		clk_unprepare(mdata->spi_clk);

	return 0;
}

#ifdef CONFIG_PM_SLEEP
static int mtk_spi_suspend(struct device *dev)
{
	int ret;
	struct spi_master *master = dev_get_drvdata(dev);
	struct mtk_spi *mdata = spi_master_get_devdata(master);

	ret = spi_master_suspend(master);
	if (ret)
		return ret;

	if (!pm_runtime_suspended(dev))
		clk_disable_unprepare(mdata->spi_clk);

	return ret;
}

static int mtk_spi_resume(struct device *dev)
{
	int ret;
	struct spi_master *master = dev_get_drvdata(dev);
	struct mtk_spi *mdata = spi_master_get_devdata(master);

	if (!pm_runtime_suspended(dev)) {
		ret = clk_prepare_enable(mdata->spi_clk);
		if (ret < 0) {
			dev_err(dev, "failed to enable spi_clk (%d)\n", ret);
			return ret;
		}
	}

	ret = spi_master_resume(master);
	if (ret < 0)
		clk_disable_unprepare(mdata->spi_clk);

	return ret;
}
#endif /* CONFIG_PM_SLEEP */

#ifdef CONFIG_PM
static int mtk_spi_runtime_suspend(struct device *dev)
{
	struct spi_master *master = dev_get_drvdata(dev);
	struct mtk_spi *mdata = spi_master_get_devdata(master);

	if (mdata->dev_comp->no_need_unprepare)
		clk_disable(mdata->spi_clk);
	else
		clk_disable_unprepare(mdata->spi_clk);

	return 0;
}

static int mtk_spi_runtime_resume(struct device *dev)
{
	struct spi_master *master = dev_get_drvdata(dev);
	struct mtk_spi *mdata = spi_master_get_devdata(master);
	int ret;

	if (mdata->dev_comp->no_need_unprepare)
		ret = clk_enable(mdata->spi_clk);
	else
		ret = clk_prepare_enable(mdata->spi_clk);
	if (ret < 0) {
		dev_err(dev, "failed to enable spi_clk (%d)\n", ret);
		return ret;
	}

	return 0;
}
#endif /* CONFIG_PM */

static const struct dev_pm_ops mtk_spi_pm = {
	SET_SYSTEM_SLEEP_PM_OPS(mtk_spi_suspend, mtk_spi_resume)
	SET_RUNTIME_PM_OPS(mtk_spi_runtime_suspend,
			   mtk_spi_runtime_resume, NULL)
};

static struct platform_driver mtk_spi_driver = {
	.driver = {
		.name = "mtk-spi",
		.pm	= &mtk_spi_pm,
		.of_match_table = mtk_spi_of_match,
	},
	.probe = mtk_spi_probe,
	.remove = mtk_spi_remove,
};

module_platform_driver(mtk_spi_driver);

MODULE_DESCRIPTION("MTK SPI Controller driver");
MODULE_AUTHOR("Leilk Liu <leilk.liu@mediatek.com>");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:mtk-spi");