xref: /openbmc/u-boot/drivers/spi/tegra210_qspi.c (revision 8ee59472)
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