xref: /openbmc/u-boot/drivers/spi/bcm63xx_hsspi.c (revision 8664ab7d)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2017 Álvaro Fernández Rojas <noltari@gmail.com>
4  *
5  * Derived from linux/drivers/spi/spi-bcm63xx-hsspi.c:
6  *	Copyright (C) 2000-2010 Broadcom Corporation
7  *	Copyright (C) 2012-2013 Jonas Gorski <jogo@openwrt.org>
8  */
9 
10 #include <common.h>
11 #include <clk.h>
12 #include <dm.h>
13 #include <spi.h>
14 #include <reset.h>
15 #include <wait_bit.h>
16 #include <asm/io.h>
17 
18 #define HSSPI_PP			0
19 
20 #define SPI_MAX_SYNC_CLOCK		30000000
21 
22 /* SPI Control register */
23 #define SPI_CTL_REG			0x000
24 #define SPI_CTL_CS_POL_SHIFT		0
25 #define SPI_CTL_CS_POL_MASK		(0xff << SPI_CTL_CS_POL_SHIFT)
26 #define SPI_CTL_CLK_GATE_SHIFT		16
27 #define SPI_CTL_CLK_GATE_MASK		(1 << SPI_CTL_CLK_GATE_SHIFT)
28 #define SPI_CTL_CLK_POL_SHIFT		17
29 #define SPI_CTL_CLK_POL_MASK		(1 << SPI_CTL_CLK_POL_SHIFT)
30 
31 /* SPI Interrupts registers */
32 #define SPI_IR_STAT_REG			0x008
33 #define SPI_IR_ST_MASK_REG		0x00c
34 #define SPI_IR_MASK_REG			0x010
35 
36 #define SPI_IR_CLEAR_ALL		0xff001f1f
37 
38 /* SPI Ping-Pong Command registers */
39 #define SPI_CMD_REG			(0x080 + (0x40 * (HSSPI_PP)) + 0x00)
40 #define SPI_CMD_OP_SHIFT		0
41 #define SPI_CMD_OP_START		(0x1 << SPI_CMD_OP_SHIFT)
42 #define SPI_CMD_PFL_SHIFT		8
43 #define SPI_CMD_PFL_MASK		(0x7 << SPI_CMD_PFL_SHIFT)
44 #define SPI_CMD_SLAVE_SHIFT		12
45 #define SPI_CMD_SLAVE_MASK		(0x7 << SPI_CMD_SLAVE_SHIFT)
46 
47 /* SPI Ping-Pong Status registers */
48 #define SPI_STAT_REG			(0x080 + (0x40 * (HSSPI_PP)) + 0x04)
49 #define SPI_STAT_SRCBUSY_SHIFT		1
50 #define SPI_STAT_SRCBUSY_MASK		(1 << SPI_STAT_SRCBUSY_SHIFT)
51 
52 /* SPI Profile Clock registers */
53 #define SPI_PFL_CLK_REG(x)		(0x100 + (0x20 * (x)) + 0x00)
54 #define SPI_PFL_CLK_FREQ_SHIFT		0
55 #define SPI_PFL_CLK_FREQ_MASK		(0x3fff << SPI_PFL_CLK_FREQ_SHIFT)
56 #define SPI_PFL_CLK_RSTLOOP_SHIFT	15
57 #define SPI_PFL_CLK_RSTLOOP_MASK	(1 << SPI_PFL_CLK_RSTLOOP_SHIFT)
58 
59 /* SPI Profile Signal registers */
60 #define SPI_PFL_SIG_REG(x)		(0x100 + (0x20 * (x)) + 0x04)
61 #define SPI_PFL_SIG_LATCHRIS_SHIFT	12
62 #define SPI_PFL_SIG_LATCHRIS_MASK	(1 << SPI_PFL_SIG_LATCHRIS_SHIFT)
63 #define SPI_PFL_SIG_LAUNCHRIS_SHIFT	13
64 #define SPI_PFL_SIG_LAUNCHRIS_MASK	(1 << SPI_PFL_SIG_LAUNCHRIS_SHIFT)
65 #define SPI_PFL_SIG_ASYNCIN_SHIFT	16
66 #define SPI_PFL_SIG_ASYNCIN_MASK	(1 << SPI_PFL_SIG_ASYNCIN_SHIFT)
67 
68 /* SPI Profile Mode registers */
69 #define SPI_PFL_MODE_REG(x)		(0x100 + (0x20 * (x)) + 0x08)
70 #define SPI_PFL_MODE_FILL_SHIFT		0
71 #define SPI_PFL_MODE_FILL_MASK		(0xff << SPI_PFL_MODE_FILL_SHIFT)
72 #define SPI_PFL_MODE_MDRDSZ_SHIFT	16
73 #define SPI_PFL_MODE_MDRDSZ_MASK	(1 << SPI_PFL_MODE_MDRDSZ_SHIFT)
74 #define SPI_PFL_MODE_MDWRSZ_SHIFT	18
75 #define SPI_PFL_MODE_MDWRSZ_MASK	(1 << SPI_PFL_MODE_MDWRSZ_SHIFT)
76 #define SPI_PFL_MODE_3WIRE_SHIFT	20
77 #define SPI_PFL_MODE_3WIRE_MASK		(1 << SPI_PFL_MODE_3WIRE_SHIFT)
78 
79 /* SPI Ping-Pong FIFO registers */
80 #define HSSPI_FIFO_SIZE			0x200
81 #define HSSPI_FIFO_BASE			(0x200 + \
82 					 (HSSPI_FIFO_SIZE * HSSPI_PP))
83 
84 /* SPI Ping-Pong FIFO OP register */
85 #define HSSPI_FIFO_OP_SIZE		0x2
86 #define HSSPI_FIFO_OP_REG		(HSSPI_FIFO_BASE + 0x00)
87 #define HSSPI_FIFO_OP_BYTES_SHIFT	0
88 #define HSSPI_FIFO_OP_BYTES_MASK	(0x3ff << HSSPI_FIFO_OP_BYTES_SHIFT)
89 #define HSSPI_FIFO_OP_MBIT_SHIFT	11
90 #define HSSPI_FIFO_OP_MBIT_MASK		(1 << HSSPI_FIFO_OP_MBIT_SHIFT)
91 #define HSSPI_FIFO_OP_CODE_SHIFT	13
92 #define HSSPI_FIFO_OP_READ_WRITE	(1 << HSSPI_FIFO_OP_CODE_SHIFT)
93 #define HSSPI_FIFO_OP_CODE_W		(2 << HSSPI_FIFO_OP_CODE_SHIFT)
94 #define HSSPI_FIFO_OP_CODE_R		(3 << HSSPI_FIFO_OP_CODE_SHIFT)
95 
96 struct bcm63xx_hsspi_priv {
97 	void __iomem *regs;
98 	ulong clk_rate;
99 	uint8_t num_cs;
100 	uint8_t cs_pols;
101 	uint speed;
102 };
103 
104 static int bcm63xx_hsspi_cs_info(struct udevice *bus, uint cs,
105 			   struct spi_cs_info *info)
106 {
107 	struct bcm63xx_hsspi_priv *priv = dev_get_priv(bus);
108 
109 	if (cs >= priv->num_cs) {
110 		printf("no cs %u\n", cs);
111 		return -ENODEV;
112 	}
113 
114 	return 0;
115 }
116 
117 static int bcm63xx_hsspi_set_mode(struct udevice *bus, uint mode)
118 {
119 	struct bcm63xx_hsspi_priv *priv = dev_get_priv(bus);
120 
121 	/* clock polarity */
122 	if (mode & SPI_CPOL)
123 		setbits_be32(priv->regs + SPI_CTL_REG, SPI_CTL_CLK_POL_MASK);
124 	else
125 		clrbits_be32(priv->regs + SPI_CTL_REG, SPI_CTL_CLK_POL_MASK);
126 
127 	return 0;
128 }
129 
130 static int bcm63xx_hsspi_set_speed(struct udevice *bus, uint speed)
131 {
132 	struct bcm63xx_hsspi_priv *priv = dev_get_priv(bus);
133 
134 	priv->speed = speed;
135 
136 	return 0;
137 }
138 
139 static void bcm63xx_hsspi_activate_cs(struct bcm63xx_hsspi_priv *priv,
140 				   struct dm_spi_slave_platdata *plat)
141 {
142 	uint32_t clr, set;
143 
144 	/* profile clock */
145 	set = DIV_ROUND_UP(priv->clk_rate, priv->speed);
146 	set = DIV_ROUND_UP(2048, set);
147 	set &= SPI_PFL_CLK_FREQ_MASK;
148 	set |= SPI_PFL_CLK_RSTLOOP_MASK;
149 	writel_be(set, priv->regs + SPI_PFL_CLK_REG(plat->cs));
150 
151 	/* profile signal */
152 	set = 0;
153 	clr = SPI_PFL_SIG_LAUNCHRIS_MASK |
154 	      SPI_PFL_SIG_LATCHRIS_MASK |
155 	      SPI_PFL_SIG_ASYNCIN_MASK;
156 
157 	/* latch/launch config */
158 	if (plat->mode & SPI_CPHA)
159 		set |= SPI_PFL_SIG_LAUNCHRIS_MASK;
160 	else
161 		set |= SPI_PFL_SIG_LATCHRIS_MASK;
162 
163 	/* async clk */
164 	if (priv->speed > SPI_MAX_SYNC_CLOCK)
165 		set |= SPI_PFL_SIG_ASYNCIN_MASK;
166 
167 	clrsetbits_be32(priv->regs + SPI_PFL_SIG_REG(plat->cs), clr, set);
168 
169 	/* global control */
170 	set = 0;
171 	clr = 0;
172 
173 	/* invert cs polarity */
174 	if (priv->cs_pols & BIT(plat->cs))
175 		clr |= BIT(plat->cs);
176 	else
177 		set |= BIT(plat->cs);
178 
179 	/* invert dummy cs polarity */
180 	if (priv->cs_pols & BIT(!plat->cs))
181 		clr |= BIT(!plat->cs);
182 	else
183 		set |= BIT(!plat->cs);
184 
185 	clrsetbits_be32(priv->regs + SPI_CTL_REG, clr, set);
186 }
187 
188 static void bcm63xx_hsspi_deactivate_cs(struct bcm63xx_hsspi_priv *priv)
189 {
190 	/* restore cs polarities */
191 	clrsetbits_be32(priv->regs + SPI_CTL_REG, SPI_CTL_CS_POL_MASK,
192 			priv->cs_pols);
193 }
194 
195 /*
196  * BCM63xx HSSPI driver doesn't allow keeping CS active between transfers
197  * because they are controlled by HW.
198  * However, it provides a mechanism to prepend write transfers prior to read
199  * transfers (with a maximum prepend of 15 bytes), which is usually enough for
200  * SPI-connected flashes since reading requires prepending a write transfer of
201  * 5 bytes. On the other hand it also provides a way to invert each CS
202  * polarity, not only between transfers like the older BCM63xx SPI driver, but
203  * also the rest of the time.
204  *
205  * Instead of using the prepend mechanism, this implementation inverts the
206  * polarity of both the desired CS and another dummy CS when the bus is
207  * claimed. This way, the dummy CS is restored to its inactive value when
208  * transfers are issued and the desired CS is preserved in its active value
209  * all the time. This hack is also used in the upstream linux driver and
210  * allows keeping CS active between trasnfers even if the HW doesn't give
211  * this possibility.
212  */
213 static int bcm63xx_hsspi_xfer(struct udevice *dev, unsigned int bitlen,
214 		const void *dout, void *din, unsigned long flags)
215 {
216 	struct bcm63xx_hsspi_priv *priv = dev_get_priv(dev->parent);
217 	struct dm_spi_slave_platdata *plat = dev_get_parent_platdata(dev);
218 	size_t data_bytes = bitlen / 8;
219 	size_t step_size = HSSPI_FIFO_SIZE;
220 	uint16_t opcode = 0;
221 	uint32_t val;
222 	const uint8_t *tx = dout;
223 	uint8_t *rx = din;
224 
225 	if (flags & SPI_XFER_BEGIN)
226 		bcm63xx_hsspi_activate_cs(priv, plat);
227 
228 	/* fifo operation */
229 	if (tx && rx)
230 		opcode = HSSPI_FIFO_OP_READ_WRITE;
231 	else if (rx)
232 		opcode = HSSPI_FIFO_OP_CODE_R;
233 	else if (tx)
234 		opcode = HSSPI_FIFO_OP_CODE_W;
235 
236 	if (opcode != HSSPI_FIFO_OP_CODE_R)
237 		step_size -= HSSPI_FIFO_OP_SIZE;
238 
239 	/* dual mode */
240 	if ((opcode == HSSPI_FIFO_OP_CODE_R && plat->mode == SPI_RX_DUAL) ||
241 	    (opcode == HSSPI_FIFO_OP_CODE_W && plat->mode == SPI_TX_DUAL))
242 		opcode |= HSSPI_FIFO_OP_MBIT_MASK;
243 
244 	/* profile mode */
245 	val = SPI_PFL_MODE_FILL_MASK |
246 	      SPI_PFL_MODE_MDRDSZ_MASK |
247 	      SPI_PFL_MODE_MDWRSZ_MASK;
248 	if (plat->mode & SPI_3WIRE)
249 		val |= SPI_PFL_MODE_3WIRE_MASK;
250 	writel_be(val, priv->regs + SPI_PFL_MODE_REG(plat->cs));
251 
252 	/* transfer loop */
253 	while (data_bytes > 0) {
254 		size_t curr_step = min(step_size, data_bytes);
255 		int ret;
256 
257 		/* copy tx data */
258 		if (tx) {
259 			memcpy_toio(priv->regs + HSSPI_FIFO_BASE +
260 				    HSSPI_FIFO_OP_SIZE, tx, curr_step);
261 			tx += curr_step;
262 		}
263 
264 		/* set fifo operation */
265 		writew_be(opcode | (curr_step & HSSPI_FIFO_OP_BYTES_MASK),
266 			  priv->regs + HSSPI_FIFO_OP_REG);
267 
268 		/* issue the transfer */
269 		val = SPI_CMD_OP_START;
270 		val |= (plat->cs << SPI_CMD_PFL_SHIFT) &
271 		       SPI_CMD_PFL_MASK;
272 		val |= (!plat->cs << SPI_CMD_SLAVE_SHIFT) &
273 		       SPI_CMD_SLAVE_MASK;
274 		writel_be(val, priv->regs + SPI_CMD_REG);
275 
276 		/* wait for completion */
277 		ret = wait_for_bit_be32(priv->regs + SPI_STAT_REG,
278 					SPI_STAT_SRCBUSY_MASK, false,
279 					1000, false);
280 		if (ret) {
281 			printf("interrupt timeout\n");
282 			return ret;
283 		}
284 
285 		/* copy rx data */
286 		if (rx) {
287 			memcpy_fromio(rx, priv->regs + HSSPI_FIFO_BASE,
288 				      curr_step);
289 			rx += curr_step;
290 		}
291 
292 		data_bytes -= curr_step;
293 	}
294 
295 	if (flags & SPI_XFER_END)
296 		bcm63xx_hsspi_deactivate_cs(priv);
297 
298 	return 0;
299 }
300 
301 static const struct dm_spi_ops bcm63xx_hsspi_ops = {
302 	.cs_info = bcm63xx_hsspi_cs_info,
303 	.set_mode = bcm63xx_hsspi_set_mode,
304 	.set_speed = bcm63xx_hsspi_set_speed,
305 	.xfer = bcm63xx_hsspi_xfer,
306 };
307 
308 static const struct udevice_id bcm63xx_hsspi_ids[] = {
309 	{ .compatible = "brcm,bcm6328-hsspi", },
310 	{ /* sentinel */ }
311 };
312 
313 static int bcm63xx_hsspi_child_pre_probe(struct udevice *dev)
314 {
315 	struct bcm63xx_hsspi_priv *priv = dev_get_priv(dev->parent);
316 	struct dm_spi_slave_platdata *plat = dev_get_parent_platdata(dev);
317 
318 	/* check cs */
319 	if (plat->cs >= priv->num_cs) {
320 		printf("no cs %u\n", plat->cs);
321 		return -ENODEV;
322 	}
323 
324 	/* cs polarity */
325 	if (plat->mode & SPI_CS_HIGH)
326 		priv->cs_pols |= BIT(plat->cs);
327 	else
328 		priv->cs_pols &= ~BIT(plat->cs);
329 
330 	return 0;
331 }
332 
333 static int bcm63xx_hsspi_probe(struct udevice *dev)
334 {
335 	struct bcm63xx_hsspi_priv *priv = dev_get_priv(dev);
336 	struct reset_ctl rst_ctl;
337 	struct clk clk;
338 	int ret;
339 
340 	priv->regs = dev_remap_addr(dev);
341 	if (!priv->regs)
342 		return -EINVAL;
343 
344 	priv->num_cs = dev_read_u32_default(dev, "num-cs", 8);
345 
346 	/* enable clock */
347 	ret = clk_get_by_name(dev, "hsspi", &clk);
348 	if (ret < 0)
349 		return ret;
350 
351 	ret = clk_enable(&clk);
352 	if (ret < 0)
353 		return ret;
354 
355 	ret = clk_free(&clk);
356 	if (ret < 0)
357 		return ret;
358 
359 	/* get clock rate */
360 	ret = clk_get_by_name(dev, "pll", &clk);
361 	if (ret < 0)
362 		return ret;
363 
364 	priv->clk_rate = clk_get_rate(&clk);
365 
366 	ret = clk_free(&clk);
367 	if (ret < 0)
368 		return ret;
369 
370 	/* perform reset */
371 	ret = reset_get_by_index(dev, 0, &rst_ctl);
372 	if (ret < 0)
373 		return ret;
374 
375 	ret = reset_deassert(&rst_ctl);
376 	if (ret < 0)
377 		return ret;
378 
379 	ret = reset_free(&rst_ctl);
380 	if (ret < 0)
381 		return ret;
382 
383 	/* initialize hardware */
384 	writel_be(0, priv->regs + SPI_IR_MASK_REG);
385 
386 	/* clear pending interrupts */
387 	writel_be(SPI_IR_CLEAR_ALL, priv->regs + SPI_IR_STAT_REG);
388 
389 	/* enable clk gate */
390 	setbits_be32(priv->regs + SPI_CTL_REG, SPI_CTL_CLK_GATE_MASK);
391 
392 	/* read default cs polarities */
393 	priv->cs_pols = readl_be(priv->regs + SPI_CTL_REG) &
394 			SPI_CTL_CS_POL_MASK;
395 
396 	return 0;
397 }
398 
399 U_BOOT_DRIVER(bcm63xx_hsspi) = {
400 	.name = "bcm63xx_hsspi",
401 	.id = UCLASS_SPI,
402 	.of_match = bcm63xx_hsspi_ids,
403 	.ops = &bcm63xx_hsspi_ops,
404 	.priv_auto_alloc_size = sizeof(struct bcm63xx_hsspi_priv),
405 	.child_pre_probe = bcm63xx_hsspi_child_pre_probe,
406 	.probe = bcm63xx_hsspi_probe,
407 };
408