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      1 // SPDX-License-Identifier: GPL-2.0+
      2 /*
      3  * NVIDIA Tegra210 QSPI controller driver
      4  *
      5  * (C) Copyright 2015 NVIDIA Corporation <www.nvidia.com>
      6  */
      7 
      8 #include <common.h>
      9 #include <dm.h>
     10 #include <asm/io.h>
     11 #include <asm/arch/clock.h>
     12 #include <asm/arch-tegra/clk_rst.h>
     13 #include <spi.h>
     14 #include <fdtdec.h>
     15 #include "tegra_spi.h"
     16 
     17 DECLARE_GLOBAL_DATA_PTR;
     18 
     19 /* COMMAND1 */
     20 #define QSPI_CMD1_GO			BIT(31)
     21 #define QSPI_CMD1_M_S			BIT(30)
     22 #define QSPI_CMD1_MODE_MASK		GENMASK(1,0)
     23 #define QSPI_CMD1_MODE_SHIFT		28
     24 #define QSPI_CMD1_CS_SEL_MASK		GENMASK(1,0)
     25 #define QSPI_CMD1_CS_SEL_SHIFT		26
     26 #define QSPI_CMD1_CS_POL_INACTIVE0	BIT(22)
     27 #define QSPI_CMD1_CS_SW_HW		BIT(21)
     28 #define QSPI_CMD1_CS_SW_VAL		BIT(20)
     29 #define QSPI_CMD1_IDLE_SDA_MASK		GENMASK(1,0)
     30 #define QSPI_CMD1_IDLE_SDA_SHIFT	18
     31 #define QSPI_CMD1_BIDIR			BIT(17)
     32 #define QSPI_CMD1_LSBI_FE		BIT(16)
     33 #define QSPI_CMD1_LSBY_FE		BIT(15)
     34 #define QSPI_CMD1_BOTH_EN_BIT		BIT(14)
     35 #define QSPI_CMD1_BOTH_EN_BYTE		BIT(13)
     36 #define QSPI_CMD1_RX_EN			BIT(12)
     37 #define QSPI_CMD1_TX_EN			BIT(11)
     38 #define QSPI_CMD1_PACKED		BIT(5)
     39 #define QSPI_CMD1_BITLEN_MASK		GENMASK(4,0)
     40 #define QSPI_CMD1_BITLEN_SHIFT		0
     41 
     42 /* COMMAND2 */
     43 #define QSPI_CMD2_TX_CLK_TAP_DELAY	BIT(6)
     44 #define QSPI_CMD2_TX_CLK_TAP_DELAY_MASK	GENMASK(11,6)
     45 #define QSPI_CMD2_RX_CLK_TAP_DELAY	BIT(0)
     46 #define QSPI_CMD2_RX_CLK_TAP_DELAY_MASK	GENMASK(5,0)
     47 
     48 /* TRANSFER STATUS */
     49 #define QSPI_XFER_STS_RDY		BIT(30)
     50 
     51 /* FIFO STATUS */
     52 #define QSPI_FIFO_STS_CS_INACTIVE	BIT(31)
     53 #define QSPI_FIFO_STS_FRAME_END		BIT(30)
     54 #define QSPI_FIFO_STS_RX_FIFO_FLUSH	BIT(15)
     55 #define QSPI_FIFO_STS_TX_FIFO_FLUSH	BIT(14)
     56 #define QSPI_FIFO_STS_ERR		BIT(8)
     57 #define QSPI_FIFO_STS_TX_FIFO_OVF	BIT(7)
     58 #define QSPI_FIFO_STS_TX_FIFO_UNR	BIT(6)
     59 #define QSPI_FIFO_STS_RX_FIFO_OVF	BIT(5)
     60 #define QSPI_FIFO_STS_RX_FIFO_UNR	BIT(4)
     61 #define QSPI_FIFO_STS_TX_FIFO_FULL	BIT(3)
     62 #define QSPI_FIFO_STS_TX_FIFO_EMPTY	BIT(2)
     63 #define QSPI_FIFO_STS_RX_FIFO_FULL	BIT(1)
     64 #define QSPI_FIFO_STS_RX_FIFO_EMPTY	BIT(0)
     65 
     66 #define QSPI_TIMEOUT		1000
     67 
     68 struct qspi_regs {
     69 	u32 command1;	/* 000:QSPI_COMMAND1 register */
     70 	u32 command2;	/* 004:QSPI_COMMAND2 register */
     71 	u32 timing1;	/* 008:QSPI_CS_TIM1 register */
     72 	u32 timing2;	/* 00c:QSPI_CS_TIM2 register */
     73 	u32 xfer_status;/* 010:QSPI_TRANS_STATUS register */
     74 	u32 fifo_status;/* 014:QSPI_FIFO_STATUS register */
     75 	u32 tx_data;	/* 018:QSPI_TX_DATA register */
     76 	u32 rx_data;	/* 01c:QSPI_RX_DATA register */
     77 	u32 dma_ctl;	/* 020:QSPI_DMA_CTL register */
     78 	u32 dma_blk;	/* 024:QSPI_DMA_BLK register */
     79 	u32 rsvd[56];	/* 028-107 reserved */
     80 	u32 tx_fifo;	/* 108:QSPI_FIFO1 register */
     81 	u32 rsvd2[31];	/* 10c-187 reserved */
     82 	u32 rx_fifo;	/* 188:QSPI_FIFO2 register */
     83 	u32 spare_ctl;	/* 18c:QSPI_SPARE_CTRL register */
     84 };
     85 
     86 struct tegra210_qspi_priv {
     87 	struct qspi_regs *regs;
     88 	unsigned int freq;
     89 	unsigned int mode;
     90 	int periph_id;
     91 	int valid;
     92 	int last_transaction_us;
     93 };
     94 
     95 static int tegra210_qspi_ofdata_to_platdata(struct udevice *bus)
     96 {
     97 	struct tegra_spi_platdata *plat = bus->platdata;
     98 	const void *blob = gd->fdt_blob;
     99 	int node = dev_of_offset(bus);
    100 
    101 	plat->base = devfdt_get_addr(bus);
    102 	plat->periph_id = clock_decode_periph_id(bus);
    103 
    104 	if (plat->periph_id == PERIPH_ID_NONE) {
    105 		debug("%s: could not decode periph id %d\n", __func__,
    106 		      plat->periph_id);
    107 		return -FDT_ERR_NOTFOUND;
    108 	}
    109 
    110 	/* Use 500KHz as a suitable default */
    111 	plat->frequency = fdtdec_get_int(blob, node, "spi-max-frequency",
    112 					500000);
    113 	plat->deactivate_delay_us = fdtdec_get_int(blob, node,
    114 					"spi-deactivate-delay", 0);
    115 	debug("%s: base=%#08lx, periph_id=%d, max-frequency=%d, deactivate_delay=%d\n",
    116 	      __func__, plat->base, plat->periph_id, plat->frequency,
    117 	      plat->deactivate_delay_us);
    118 
    119 	return 0;
    120 }
    121 
    122 static int tegra210_qspi_probe(struct udevice *bus)
    123 {
    124 	struct tegra_spi_platdata *plat = dev_get_platdata(bus);
    125 	struct tegra210_qspi_priv *priv = dev_get_priv(bus);
    126 
    127 	priv->regs = (struct qspi_regs *)plat->base;
    128 
    129 	priv->last_transaction_us = timer_get_us();
    130 	priv->freq = plat->frequency;
    131 	priv->periph_id = plat->periph_id;
    132 
    133 	/* Change SPI clock to correct frequency, PLLP_OUT0 source */
    134 	clock_start_periph_pll(priv->periph_id, CLOCK_ID_PERIPH, priv->freq);
    135 
    136 	return 0;
    137 }
    138 
    139 static int tegra210_qspi_claim_bus(struct udevice *bus)
    140 {
    141 	struct tegra210_qspi_priv *priv = dev_get_priv(bus);
    142 	struct qspi_regs *regs = priv->regs;
    143 
    144 	/* Change SPI clock to correct frequency, PLLP_OUT0 source */
    145 	clock_start_periph_pll(priv->periph_id, CLOCK_ID_PERIPH, priv->freq);
    146 
    147 	debug("%s: FIFO STATUS = %08x\n", __func__, readl(&regs->fifo_status));
    148 
    149 	/* Set master mode and sw controlled CS */
    150 	setbits_le32(&regs->command1, QSPI_CMD1_M_S | QSPI_CMD1_CS_SW_HW |
    151 		     (priv->mode << QSPI_CMD1_MODE_SHIFT));
    152 	debug("%s: COMMAND1 = %08x\n", __func__, readl(&regs->command1));
    153 
    154 	return 0;
    155 }
    156 
    157 /**
    158  * Activate the CS by driving it LOW
    159  *
    160  * @param slave	Pointer to spi_slave to which controller has to
    161  *		communicate with
    162  */
    163 static void spi_cs_activate(struct udevice *dev)
    164 {
    165 	struct udevice *bus = dev->parent;
    166 	struct tegra_spi_platdata *pdata = dev_get_platdata(bus);
    167 	struct tegra210_qspi_priv *priv = dev_get_priv(bus);
    168 
    169 	/* If it's too soon to do another transaction, wait */
    170 	if (pdata->deactivate_delay_us &&
    171 	    priv->last_transaction_us) {
    172 		ulong delay_us;		/* The delay completed so far */
    173 		delay_us = timer_get_us() - priv->last_transaction_us;
    174 		if (delay_us < pdata->deactivate_delay_us)
    175 			udelay(pdata->deactivate_delay_us - delay_us);
    176 	}
    177 
    178 	clrbits_le32(&priv->regs->command1, QSPI_CMD1_CS_SW_VAL);
    179 }
    180 
    181 /**
    182  * Deactivate the CS by driving it HIGH
    183  *
    184  * @param slave	Pointer to spi_slave to which controller has to
    185  *		communicate with
    186  */
    187 static void spi_cs_deactivate(struct udevice *dev)
    188 {
    189 	struct udevice *bus = dev->parent;
    190 	struct tegra_spi_platdata *pdata = dev_get_platdata(bus);
    191 	struct tegra210_qspi_priv *priv = dev_get_priv(bus);
    192 
    193 	setbits_le32(&priv->regs->command1, QSPI_CMD1_CS_SW_VAL);
    194 
    195 	/* Remember time of this transaction so we can honour the bus delay */
    196 	if (pdata->deactivate_delay_us)
    197 		priv->last_transaction_us = timer_get_us();
    198 
    199 	debug("Deactivate CS, bus '%s'\n", bus->name);
    200 }
    201 
    202 static int tegra210_qspi_xfer(struct udevice *dev, unsigned int bitlen,
    203 			     const void *data_out, void *data_in,
    204 			     unsigned long flags)
    205 {
    206 	struct udevice *bus = dev->parent;
    207 	struct tegra210_qspi_priv *priv = dev_get_priv(bus);
    208 	struct qspi_regs *regs = priv->regs;
    209 	u32 reg, tmpdout, tmpdin = 0;
    210 	const u8 *dout = data_out;
    211 	u8 *din = data_in;
    212 	int num_bytes, tm, ret;
    213 
    214 	debug("%s: slave %u:%u dout %p din %p bitlen %u\n",
    215 	      __func__, bus->seq, spi_chip_select(dev), dout, din, bitlen);
    216 	if (bitlen % 8)
    217 		return -1;
    218 	num_bytes = bitlen / 8;
    219 
    220 	ret = 0;
    221 
    222 	/* clear all error status bits */
    223 	reg = readl(&regs->fifo_status);
    224 	writel(reg, &regs->fifo_status);
    225 
    226 	/* flush RX/TX FIFOs */
    227 	setbits_le32(&regs->fifo_status,
    228 		     (QSPI_FIFO_STS_RX_FIFO_FLUSH |
    229 		      QSPI_FIFO_STS_TX_FIFO_FLUSH));
    230 
    231 	tm = QSPI_TIMEOUT;
    232 	while ((tm && readl(&regs->fifo_status) &
    233 		      (QSPI_FIFO_STS_RX_FIFO_FLUSH |
    234 		       QSPI_FIFO_STS_TX_FIFO_FLUSH))) {
    235 		tm--;
    236 		udelay(1);
    237 	}
    238 
    239 	if (!tm) {
    240 		printf("%s: timeout during QSPI FIFO flush!\n",
    241 		       __func__);
    242 		return -1;
    243 	}
    244 
    245 	/*
    246 	 * Notes:
    247 	 *   1. don't set LSBY_FE, so no need to swap bytes from/to TX/RX FIFOs;
    248 	 *   2. don't set RX_EN and TX_EN yet.
    249 	 *      (SW needs to make sure that while programming the blk_size,
    250 	 *       tx_en and rx_en bits must be zero)
    251 	 *      [TODO] I (Yen Lin) have problems when both RX/TX EN bits are set
    252 	 *	       i.e., both dout and din are not NULL.
    253 	 */
    254 	clrsetbits_le32(&regs->command1,
    255 			(QSPI_CMD1_LSBI_FE | QSPI_CMD1_LSBY_FE |
    256 			 QSPI_CMD1_RX_EN | QSPI_CMD1_TX_EN),
    257 			(spi_chip_select(dev) << QSPI_CMD1_CS_SEL_SHIFT));
    258 
    259 	/* set xfer size to 1 block (32 bits) */
    260 	writel(0, &regs->dma_blk);
    261 
    262 	if (flags & SPI_XFER_BEGIN)
    263 		spi_cs_activate(dev);
    264 
    265 	/* handle data in 32-bit chunks */
    266 	while (num_bytes > 0) {
    267 		int bytes;
    268 
    269 		tmpdout = 0;
    270 		bytes = (num_bytes > 4) ?  4 : num_bytes;
    271 
    272 		if (dout != NULL) {
    273 			memcpy((void *)&tmpdout, (void *)dout, bytes);
    274 			dout += bytes;
    275 			num_bytes -= bytes;
    276 			writel(tmpdout, &regs->tx_fifo);
    277 			setbits_le32(&regs->command1, QSPI_CMD1_TX_EN);
    278 		}
    279 
    280 		if (din != NULL)
    281 			setbits_le32(&regs->command1, QSPI_CMD1_RX_EN);
    282 
    283 		/* clear ready bit */
    284 		setbits_le32(&regs->xfer_status, QSPI_XFER_STS_RDY);
    285 
    286 		clrsetbits_le32(&regs->command1,
    287 				QSPI_CMD1_BITLEN_MASK << QSPI_CMD1_BITLEN_SHIFT,
    288 				(bytes * 8 - 1) << QSPI_CMD1_BITLEN_SHIFT);
    289 
    290 		/* Need to stabilize other reg bits before GO bit set.
    291 		 * As per the TRM:
    292 		 * "For successful operation at various freq combinations,
    293 		 * a minimum of 4-5 spi_clk cycle delay might be required
    294 		 * before enabling the PIO or DMA bits. The worst case delay
    295 		 * calculation can be done considering slowest qspi_clk as
    296 		 * 1MHz. Based on that 1us delay should be enough before
    297 		 * enabling PIO or DMA." Padded another 1us for safety.
    298 		 */
    299 		udelay(2);
    300 		setbits_le32(&regs->command1, QSPI_CMD1_GO);
    301 		udelay(1);
    302 
    303 		/*
    304 		 * Wait for SPI transmit FIFO to empty, or to time out.
    305 		 * The RX FIFO status will be read and cleared last
    306 		 */
    307 		for (tm = 0; tm < QSPI_TIMEOUT; ++tm) {
    308 			u32 fifo_status, xfer_status;
    309 
    310 			xfer_status = readl(&regs->xfer_status);
    311 			if (!(xfer_status & QSPI_XFER_STS_RDY))
    312 				continue;
    313 
    314 			fifo_status = readl(&regs->fifo_status);
    315 			if (fifo_status & QSPI_FIFO_STS_ERR) {
    316 				debug("%s: got a fifo error: ", __func__);
    317 				if (fifo_status & QSPI_FIFO_STS_TX_FIFO_OVF)
    318 					debug("tx FIFO overflow ");
    319 				if (fifo_status & QSPI_FIFO_STS_TX_FIFO_UNR)
    320 					debug("tx FIFO underrun ");
    321 				if (fifo_status & QSPI_FIFO_STS_RX_FIFO_OVF)
    322 					debug("rx FIFO overflow ");
    323 				if (fifo_status & QSPI_FIFO_STS_RX_FIFO_UNR)
    324 					debug("rx FIFO underrun ");
    325 				if (fifo_status & QSPI_FIFO_STS_TX_FIFO_FULL)
    326 					debug("tx FIFO full ");
    327 				if (fifo_status & QSPI_FIFO_STS_TX_FIFO_EMPTY)
    328 					debug("tx FIFO empty ");
    329 				if (fifo_status & QSPI_FIFO_STS_RX_FIFO_FULL)
    330 					debug("rx FIFO full ");
    331 				if (fifo_status & QSPI_FIFO_STS_RX_FIFO_EMPTY)
    332 					debug("rx FIFO empty ");
    333 				debug("\n");
    334 				break;
    335 			}
    336 
    337 			if (!(fifo_status & QSPI_FIFO_STS_RX_FIFO_EMPTY)) {
    338 				tmpdin = readl(&regs->rx_fifo);
    339 				if (din != NULL) {
    340 					memcpy(din, &tmpdin, bytes);
    341 					din += bytes;
    342 					num_bytes -= bytes;
    343 				}
    344 			}
    345 			break;
    346 		}
    347 
    348 		if (tm >= QSPI_TIMEOUT)
    349 			ret = tm;
    350 
    351 		/* clear ACK RDY, etc. bits */
    352 		writel(readl(&regs->fifo_status), &regs->fifo_status);
    353 	}
    354 
    355 	if (flags & SPI_XFER_END)
    356 		spi_cs_deactivate(dev);
    357 
    358 	debug("%s: transfer ended. Value=%08x, fifo_status = %08x\n",
    359 	      __func__, tmpdin, readl(&regs->fifo_status));
    360 
    361 	if (ret) {
    362 		printf("%s: timeout during SPI transfer, tm %d\n",
    363 		       __func__, ret);
    364 		return -1;
    365 	}
    366 
    367 	return ret;
    368 }
    369 
    370 static int tegra210_qspi_set_speed(struct udevice *bus, uint speed)
    371 {
    372 	struct tegra_spi_platdata *plat = bus->platdata;
    373 	struct tegra210_qspi_priv *priv = dev_get_priv(bus);
    374 
    375 	if (speed > plat->frequency)
    376 		speed = plat->frequency;
    377 	priv->freq = speed;
    378 	debug("%s: regs=%p, speed=%d\n", __func__, priv->regs, priv->freq);
    379 
    380 	return 0;
    381 }
    382 
    383 static int tegra210_qspi_set_mode(struct udevice *bus, uint mode)
    384 {
    385 	struct tegra210_qspi_priv *priv = dev_get_priv(bus);
    386 
    387 	priv->mode = mode;
    388 	debug("%s: regs=%p, mode=%d\n", __func__, priv->regs, priv->mode);
    389 
    390 	return 0;
    391 }
    392 
    393 static const struct dm_spi_ops tegra210_qspi_ops = {
    394 	.claim_bus	= tegra210_qspi_claim_bus,
    395 	.xfer		= tegra210_qspi_xfer,
    396 	.set_speed	= tegra210_qspi_set_speed,
    397 	.set_mode	= tegra210_qspi_set_mode,
    398 	/*
    399 	 * cs_info is not needed, since we require all chip selects to be
    400 	 * in the device tree explicitly
    401 	 */
    402 };
    403 
    404 static const struct udevice_id tegra210_qspi_ids[] = {
    405 	{ .compatible = "nvidia,tegra210-qspi" },
    406 	{ }
    407 };
    408 
    409 U_BOOT_DRIVER(tegra210_qspi) = {
    410 	.name = "tegra210-qspi",
    411 	.id = UCLASS_SPI,
    412 	.of_match = tegra210_qspi_ids,
    413 	.ops = &tegra210_qspi_ops,
    414 	.ofdata_to_platdata = tegra210_qspi_ofdata_to_platdata,
    415 	.platdata_auto_alloc_size = sizeof(struct tegra_spi_platdata),
    416 	.priv_auto_alloc_size = sizeof(struct tegra210_qspi_priv),
    417 	.per_child_auto_alloc_size = sizeof(struct spi_slave),
    418 	.probe = tegra210_qspi_probe,
    419 };
    420