xref: /openbmc/u-boot/drivers/spi/tegra210_qspi.c (revision 6e87ae1c)
1 /*
2  * NVIDIA Tegra210 QSPI controller driver
3  *
4  * (C) Copyright 2015 NVIDIA Corporation <www.nvidia.com>
5  *
6  * SPDX-License-Identifier:     GPL-2.0+
7  */
8 
9 #include <common.h>
10 #include <dm.h>
11 #include <asm/io.h>
12 #include <asm/arch/clock.h>
13 #include <asm/arch-tegra/clk_rst.h>
14 #include <spi.h>
15 #include <fdtdec.h>
16 #include "tegra_spi.h"
17 
18 DECLARE_GLOBAL_DATA_PTR;
19 
20 /* COMMAND1 */
21 #define QSPI_CMD1_GO			BIT(31)
22 #define QSPI_CMD1_M_S			BIT(30)
23 #define QSPI_CMD1_MODE_MASK		GENMASK(1,0)
24 #define QSPI_CMD1_MODE_SHIFT		28
25 #define QSPI_CMD1_CS_SEL_MASK		GENMASK(1,0)
26 #define QSPI_CMD1_CS_SEL_SHIFT		26
27 #define QSPI_CMD1_CS_POL_INACTIVE0	BIT(22)
28 #define QSPI_CMD1_CS_SW_HW		BIT(21)
29 #define QSPI_CMD1_CS_SW_VAL		BIT(20)
30 #define QSPI_CMD1_IDLE_SDA_MASK		GENMASK(1,0)
31 #define QSPI_CMD1_IDLE_SDA_SHIFT	18
32 #define QSPI_CMD1_BIDIR			BIT(17)
33 #define QSPI_CMD1_LSBI_FE		BIT(16)
34 #define QSPI_CMD1_LSBY_FE		BIT(15)
35 #define QSPI_CMD1_BOTH_EN_BIT		BIT(14)
36 #define QSPI_CMD1_BOTH_EN_BYTE		BIT(13)
37 #define QSPI_CMD1_RX_EN			BIT(12)
38 #define QSPI_CMD1_TX_EN			BIT(11)
39 #define QSPI_CMD1_PACKED		BIT(5)
40 #define QSPI_CMD1_BITLEN_MASK		GENMASK(4,0)
41 #define QSPI_CMD1_BITLEN_SHIFT		0
42 
43 /* COMMAND2 */
44 #define QSPI_CMD2_TX_CLK_TAP_DELAY	BIT(6)
45 #define QSPI_CMD2_TX_CLK_TAP_DELAY_MASK	GENMASK(11,6)
46 #define QSPI_CMD2_RX_CLK_TAP_DELAY	BIT(0)
47 #define QSPI_CMD2_RX_CLK_TAP_DELAY_MASK	GENMASK(5,0)
48 
49 /* TRANSFER STATUS */
50 #define QSPI_XFER_STS_RDY		BIT(30)
51 
52 /* FIFO STATUS */
53 #define QSPI_FIFO_STS_CS_INACTIVE	BIT(31)
54 #define QSPI_FIFO_STS_FRAME_END		BIT(30)
55 #define QSPI_FIFO_STS_RX_FIFO_FLUSH	BIT(15)
56 #define QSPI_FIFO_STS_TX_FIFO_FLUSH	BIT(14)
57 #define QSPI_FIFO_STS_ERR		BIT(8)
58 #define QSPI_FIFO_STS_TX_FIFO_OVF	BIT(7)
59 #define QSPI_FIFO_STS_TX_FIFO_UNR	BIT(6)
60 #define QSPI_FIFO_STS_RX_FIFO_OVF	BIT(5)
61 #define QSPI_FIFO_STS_RX_FIFO_UNR	BIT(4)
62 #define QSPI_FIFO_STS_TX_FIFO_FULL	BIT(3)
63 #define QSPI_FIFO_STS_TX_FIFO_EMPTY	BIT(2)
64 #define QSPI_FIFO_STS_RX_FIFO_FULL	BIT(1)
65 #define QSPI_FIFO_STS_RX_FIFO_EMPTY	BIT(0)
66 
67 #define QSPI_TIMEOUT		1000
68 
69 struct qspi_regs {
70 	u32 command1;	/* 000:QSPI_COMMAND1 register */
71 	u32 command2;	/* 004:QSPI_COMMAND2 register */
72 	u32 timing1;	/* 008:QSPI_CS_TIM1 register */
73 	u32 timing2;	/* 00c:QSPI_CS_TIM2 register */
74 	u32 xfer_status;/* 010:QSPI_TRANS_STATUS register */
75 	u32 fifo_status;/* 014:QSPI_FIFO_STATUS register */
76 	u32 tx_data;	/* 018:QSPI_TX_DATA register */
77 	u32 rx_data;	/* 01c:QSPI_RX_DATA register */
78 	u32 dma_ctl;	/* 020:QSPI_DMA_CTL register */
79 	u32 dma_blk;	/* 024:QSPI_DMA_BLK register */
80 	u32 rsvd[56];	/* 028-107 reserved */
81 	u32 tx_fifo;	/* 108:QSPI_FIFO1 register */
82 	u32 rsvd2[31];	/* 10c-187 reserved */
83 	u32 rx_fifo;	/* 188:QSPI_FIFO2 register */
84 	u32 spare_ctl;	/* 18c:QSPI_SPARE_CTRL register */
85 };
86 
87 struct tegra210_qspi_priv {
88 	struct qspi_regs *regs;
89 	unsigned int freq;
90 	unsigned int mode;
91 	int periph_id;
92 	int valid;
93 	int last_transaction_us;
94 };
95 
96 static int tegra210_qspi_ofdata_to_platdata(struct udevice *bus)
97 {
98 	struct tegra_spi_platdata *plat = bus->platdata;
99 	const void *blob = gd->fdt_blob;
100 	int node = dev_of_offset(bus);
101 
102 	plat->base = devfdt_get_addr(bus);
103 	plat->periph_id = clock_decode_periph_id(blob, node);
104 
105 	if (plat->periph_id == PERIPH_ID_NONE) {
106 		debug("%s: could not decode periph id %d\n", __func__,
107 		      plat->periph_id);
108 		return -FDT_ERR_NOTFOUND;
109 	}
110 
111 	/* Use 500KHz as a suitable default */
112 	plat->frequency = fdtdec_get_int(blob, node, "spi-max-frequency",
113 					500000);
114 	plat->deactivate_delay_us = fdtdec_get_int(blob, node,
115 					"spi-deactivate-delay", 0);
116 	debug("%s: base=%#08lx, periph_id=%d, max-frequency=%d, deactivate_delay=%d\n",
117 	      __func__, plat->base, plat->periph_id, plat->frequency,
118 	      plat->deactivate_delay_us);
119 
120 	return 0;
121 }
122 
123 static int tegra210_qspi_probe(struct udevice *bus)
124 {
125 	struct tegra_spi_platdata *plat = dev_get_platdata(bus);
126 	struct tegra210_qspi_priv *priv = dev_get_priv(bus);
127 
128 	priv->regs = (struct qspi_regs *)plat->base;
129 
130 	priv->last_transaction_us = timer_get_us();
131 	priv->freq = plat->frequency;
132 	priv->periph_id = plat->periph_id;
133 
134 	/* Change SPI clock to correct frequency, PLLP_OUT0 source */
135 	clock_start_periph_pll(priv->periph_id, CLOCK_ID_PERIPH, priv->freq);
136 
137 	return 0;
138 }
139 
140 static int tegra210_qspi_claim_bus(struct udevice *bus)
141 {
142 	struct tegra210_qspi_priv *priv = dev_get_priv(bus);
143 	struct qspi_regs *regs = priv->regs;
144 
145 	/* Change SPI clock to correct frequency, PLLP_OUT0 source */
146 	clock_start_periph_pll(priv->periph_id, CLOCK_ID_PERIPH, priv->freq);
147 
148 	debug("%s: FIFO STATUS = %08x\n", __func__, readl(&regs->fifo_status));
149 
150 	/* Set master mode and sw controlled CS */
151 	setbits_le32(&regs->command1, QSPI_CMD1_M_S | QSPI_CMD1_CS_SW_HW |
152 		     (priv->mode << QSPI_CMD1_MODE_SHIFT));
153 	debug("%s: COMMAND1 = %08x\n", __func__, readl(&regs->command1));
154 
155 	return 0;
156 }
157 
158 /**
159  * Activate the CS by driving it LOW
160  *
161  * @param slave	Pointer to spi_slave to which controller has to
162  *		communicate with
163  */
164 static void spi_cs_activate(struct udevice *dev)
165 {
166 	struct udevice *bus = dev->parent;
167 	struct tegra_spi_platdata *pdata = dev_get_platdata(bus);
168 	struct tegra210_qspi_priv *priv = dev_get_priv(bus);
169 
170 	/* If it's too soon to do another transaction, wait */
171 	if (pdata->deactivate_delay_us &&
172 	    priv->last_transaction_us) {
173 		ulong delay_us;		/* The delay completed so far */
174 		delay_us = timer_get_us() - priv->last_transaction_us;
175 		if (delay_us < pdata->deactivate_delay_us)
176 			udelay(pdata->deactivate_delay_us - delay_us);
177 	}
178 
179 	clrbits_le32(&priv->regs->command1, QSPI_CMD1_CS_SW_VAL);
180 }
181 
182 /**
183  * Deactivate the CS by driving it HIGH
184  *
185  * @param slave	Pointer to spi_slave to which controller has to
186  *		communicate with
187  */
188 static void spi_cs_deactivate(struct udevice *dev)
189 {
190 	struct udevice *bus = dev->parent;
191 	struct tegra_spi_platdata *pdata = dev_get_platdata(bus);
192 	struct tegra210_qspi_priv *priv = dev_get_priv(bus);
193 
194 	setbits_le32(&priv->regs->command1, QSPI_CMD1_CS_SW_VAL);
195 
196 	/* Remember time of this transaction so we can honour the bus delay */
197 	if (pdata->deactivate_delay_us)
198 		priv->last_transaction_us = timer_get_us();
199 
200 	debug("Deactivate CS, bus '%s'\n", bus->name);
201 }
202 
203 static int tegra210_qspi_xfer(struct udevice *dev, unsigned int bitlen,
204 			     const void *data_out, void *data_in,
205 			     unsigned long flags)
206 {
207 	struct udevice *bus = dev->parent;
208 	struct tegra210_qspi_priv *priv = dev_get_priv(bus);
209 	struct qspi_regs *regs = priv->regs;
210 	u32 reg, tmpdout, tmpdin = 0;
211 	const u8 *dout = data_out;
212 	u8 *din = data_in;
213 	int num_bytes, tm, ret;
214 
215 	debug("%s: slave %u:%u dout %p din %p bitlen %u\n",
216 	      __func__, bus->seq, spi_chip_select(dev), dout, din, bitlen);
217 	if (bitlen % 8)
218 		return -1;
219 	num_bytes = bitlen / 8;
220 
221 	ret = 0;
222 
223 	/* clear all error status bits */
224 	reg = readl(&regs->fifo_status);
225 	writel(reg, &regs->fifo_status);
226 
227 	/* flush RX/TX FIFOs */
228 	setbits_le32(&regs->fifo_status,
229 		     (QSPI_FIFO_STS_RX_FIFO_FLUSH |
230 		      QSPI_FIFO_STS_TX_FIFO_FLUSH));
231 
232 	tm = QSPI_TIMEOUT;
233 	while ((tm && readl(&regs->fifo_status) &
234 		      (QSPI_FIFO_STS_RX_FIFO_FLUSH |
235 		       QSPI_FIFO_STS_TX_FIFO_FLUSH))) {
236 		tm--;
237 		udelay(1);
238 	}
239 
240 	if (!tm) {
241 		printf("%s: timeout during QSPI FIFO flush!\n",
242 		       __func__);
243 		return -1;
244 	}
245 
246 	/*
247 	 * Notes:
248 	 *   1. don't set LSBY_FE, so no need to swap bytes from/to TX/RX FIFOs;
249 	 *   2. don't set RX_EN and TX_EN yet.
250 	 *      (SW needs to make sure that while programming the blk_size,
251 	 *       tx_en and rx_en bits must be zero)
252 	 *      [TODO] I (Yen Lin) have problems when both RX/TX EN bits are set
253 	 *	       i.e., both dout and din are not NULL.
254 	 */
255 	clrsetbits_le32(&regs->command1,
256 			(QSPI_CMD1_LSBI_FE | QSPI_CMD1_LSBY_FE |
257 			 QSPI_CMD1_RX_EN | QSPI_CMD1_TX_EN),
258 			(spi_chip_select(dev) << QSPI_CMD1_CS_SEL_SHIFT));
259 
260 	/* set xfer size to 1 block (32 bits) */
261 	writel(0, &regs->dma_blk);
262 
263 	if (flags & SPI_XFER_BEGIN)
264 		spi_cs_activate(dev);
265 
266 	/* handle data in 32-bit chunks */
267 	while (num_bytes > 0) {
268 		int bytes;
269 
270 		tmpdout = 0;
271 		bytes = (num_bytes > 4) ?  4 : num_bytes;
272 
273 		if (dout != NULL) {
274 			memcpy((void *)&tmpdout, (void *)dout, bytes);
275 			dout += bytes;
276 			num_bytes -= bytes;
277 			writel(tmpdout, &regs->tx_fifo);
278 			setbits_le32(&regs->command1, QSPI_CMD1_TX_EN);
279 		}
280 
281 		if (din != NULL)
282 			setbits_le32(&regs->command1, QSPI_CMD1_RX_EN);
283 
284 		/* clear ready bit */
285 		setbits_le32(&regs->xfer_status, QSPI_XFER_STS_RDY);
286 
287 		clrsetbits_le32(&regs->command1,
288 				QSPI_CMD1_BITLEN_MASK << QSPI_CMD1_BITLEN_SHIFT,
289 				(bytes * 8 - 1) << QSPI_CMD1_BITLEN_SHIFT);
290 
291 		/* Need to stabilize other reg bits before GO bit set.
292 		 * As per the TRM:
293 		 * "For successful operation at various freq combinations,
294 		 * a minimum of 4-5 spi_clk cycle delay might be required
295 		 * before enabling the PIO or DMA bits. The worst case delay
296 		 * calculation can be done considering slowest qspi_clk as
297 		 * 1MHz. Based on that 1us delay should be enough before
298 		 * enabling PIO or DMA." Padded another 1us for safety.
299 		 */
300 		udelay(2);
301 		setbits_le32(&regs->command1, QSPI_CMD1_GO);
302 		udelay(1);
303 
304 		/*
305 		 * Wait for SPI transmit FIFO to empty, or to time out.
306 		 * The RX FIFO status will be read and cleared last
307 		 */
308 		for (tm = 0; tm < QSPI_TIMEOUT; ++tm) {
309 			u32 fifo_status, xfer_status;
310 
311 			xfer_status = readl(&regs->xfer_status);
312 			if (!(xfer_status & QSPI_XFER_STS_RDY))
313 				continue;
314 
315 			fifo_status = readl(&regs->fifo_status);
316 			if (fifo_status & QSPI_FIFO_STS_ERR) {
317 				debug("%s: got a fifo error: ", __func__);
318 				if (fifo_status & QSPI_FIFO_STS_TX_FIFO_OVF)
319 					debug("tx FIFO overflow ");
320 				if (fifo_status & QSPI_FIFO_STS_TX_FIFO_UNR)
321 					debug("tx FIFO underrun ");
322 				if (fifo_status & QSPI_FIFO_STS_RX_FIFO_OVF)
323 					debug("rx FIFO overflow ");
324 				if (fifo_status & QSPI_FIFO_STS_RX_FIFO_UNR)
325 					debug("rx FIFO underrun ");
326 				if (fifo_status & QSPI_FIFO_STS_TX_FIFO_FULL)
327 					debug("tx FIFO full ");
328 				if (fifo_status & QSPI_FIFO_STS_TX_FIFO_EMPTY)
329 					debug("tx FIFO empty ");
330 				if (fifo_status & QSPI_FIFO_STS_RX_FIFO_FULL)
331 					debug("rx FIFO full ");
332 				if (fifo_status & QSPI_FIFO_STS_RX_FIFO_EMPTY)
333 					debug("rx FIFO empty ");
334 				debug("\n");
335 				break;
336 			}
337 
338 			if (!(fifo_status & QSPI_FIFO_STS_RX_FIFO_EMPTY)) {
339 				tmpdin = readl(&regs->rx_fifo);
340 				if (din != NULL) {
341 					memcpy(din, &tmpdin, bytes);
342 					din += bytes;
343 					num_bytes -= bytes;
344 				}
345 			}
346 			break;
347 		}
348 
349 		if (tm >= QSPI_TIMEOUT)
350 			ret = tm;
351 
352 		/* clear ACK RDY, etc. bits */
353 		writel(readl(&regs->fifo_status), &regs->fifo_status);
354 	}
355 
356 	if (flags & SPI_XFER_END)
357 		spi_cs_deactivate(dev);
358 
359 	debug("%s: transfer ended. Value=%08x, fifo_status = %08x\n",
360 	      __func__, tmpdin, readl(&regs->fifo_status));
361 
362 	if (ret) {
363 		printf("%s: timeout during SPI transfer, tm %d\n",
364 		       __func__, ret);
365 		return -1;
366 	}
367 
368 	return ret;
369 }
370 
371 static int tegra210_qspi_set_speed(struct udevice *bus, uint speed)
372 {
373 	struct tegra_spi_platdata *plat = bus->platdata;
374 	struct tegra210_qspi_priv *priv = dev_get_priv(bus);
375 
376 	if (speed > plat->frequency)
377 		speed = plat->frequency;
378 	priv->freq = speed;
379 	debug("%s: regs=%p, speed=%d\n", __func__, priv->regs, priv->freq);
380 
381 	return 0;
382 }
383 
384 static int tegra210_qspi_set_mode(struct udevice *bus, uint mode)
385 {
386 	struct tegra210_qspi_priv *priv = dev_get_priv(bus);
387 
388 	priv->mode = mode;
389 	debug("%s: regs=%p, mode=%d\n", __func__, priv->regs, priv->mode);
390 
391 	return 0;
392 }
393 
394 static const struct dm_spi_ops tegra210_qspi_ops = {
395 	.claim_bus	= tegra210_qspi_claim_bus,
396 	.xfer		= tegra210_qspi_xfer,
397 	.set_speed	= tegra210_qspi_set_speed,
398 	.set_mode	= tegra210_qspi_set_mode,
399 	/*
400 	 * cs_info is not needed, since we require all chip selects to be
401 	 * in the device tree explicitly
402 	 */
403 };
404 
405 static const struct udevice_id tegra210_qspi_ids[] = {
406 	{ .compatible = "nvidia,tegra210-qspi" },
407 	{ }
408 };
409 
410 U_BOOT_DRIVER(tegra210_qspi) = {
411 	.name = "tegra210-qspi",
412 	.id = UCLASS_SPI,
413 	.of_match = tegra210_qspi_ids,
414 	.ops = &tegra210_qspi_ops,
415 	.ofdata_to_platdata = tegra210_qspi_ofdata_to_platdata,
416 	.platdata_auto_alloc_size = sizeof(struct tegra_spi_platdata),
417 	.priv_auto_alloc_size = sizeof(struct tegra210_qspi_priv),
418 	.per_child_auto_alloc_size = sizeof(struct spi_slave),
419 	.probe = tegra210_qspi_probe,
420 };
421