xref: /openbmc/u-boot/drivers/spi/bcm63xx_hsspi.c (revision 0093b3fc)
1 /*
2  * Copyright (C) 2017 Álvaro Fernández Rojas <noltari@gmail.com>
3  *
4  * Derived from linux/drivers/spi/spi-bcm63xx-hsspi.c:
5  *	Copyright (C) 2000-2010 Broadcom Corporation
6  *	Copyright (C) 2012-2013 Jonas Gorski <jogo@openwrt.org>
7  *
8  * SPDX-License-Identifier: GPL-2.0+
9  */
10 
11 #include <common.h>
12 #include <clk.h>
13 #include <dm.h>
14 #include <spi.h>
15 #include <reset.h>
16 #include <wait_bit.h>
17 #include <asm/io.h>
18 
19 DECLARE_GLOBAL_DATA_PTR;
20 
21 #define HSSPI_PP			0
22 
23 #define SPI_MAX_SYNC_CLOCK		30000000
24 
25 /* SPI Control register */
26 #define SPI_CTL_REG			0x000
27 #define SPI_CTL_CS_POL_SHIFT		0
28 #define SPI_CTL_CS_POL_MASK		(0xff << SPI_CTL_CS_POL_SHIFT)
29 #define SPI_CTL_CLK_GATE_SHIFT		16
30 #define SPI_CTL_CLK_GATE_MASK		(1 << SPI_CTL_CLK_GATE_SHIFT)
31 #define SPI_CTL_CLK_POL_SHIFT		17
32 #define SPI_CTL_CLK_POL_MASK		(1 << SPI_CTL_CLK_POL_SHIFT)
33 
34 /* SPI Interrupts registers */
35 #define SPI_IR_STAT_REG			0x008
36 #define SPI_IR_ST_MASK_REG		0x00c
37 #define SPI_IR_MASK_REG			0x010
38 
39 #define SPI_IR_CLEAR_ALL		0xff001f1f
40 
41 /* SPI Ping-Pong Command registers */
42 #define SPI_CMD_REG			(0x080 + (0x40 * (HSSPI_PP)) + 0x00)
43 #define SPI_CMD_OP_SHIFT		0
44 #define SPI_CMD_OP_START		(0x1 << SPI_CMD_OP_SHIFT)
45 #define SPI_CMD_PFL_SHIFT		8
46 #define SPI_CMD_PFL_MASK		(0x7 << SPI_CMD_PFL_SHIFT)
47 #define SPI_CMD_SLAVE_SHIFT		12
48 #define SPI_CMD_SLAVE_MASK		(0x7 << SPI_CMD_SLAVE_SHIFT)
49 
50 /* SPI Ping-Pong Status registers */
51 #define SPI_STAT_REG			(0x080 + (0x40 * (HSSPI_PP)) + 0x04)
52 #define SPI_STAT_SRCBUSY_SHIFT		1
53 #define SPI_STAT_SRCBUSY_MASK		(1 << SPI_STAT_SRCBUSY_SHIFT)
54 
55 /* SPI Profile Clock registers */
56 #define SPI_PFL_CLK_REG(x)		(0x100 + (0x20 * (x)) + 0x00)
57 #define SPI_PFL_CLK_FREQ_SHIFT		0
58 #define SPI_PFL_CLK_FREQ_MASK		(0x3fff << SPI_PFL_CLK_FREQ_SHIFT)
59 #define SPI_PFL_CLK_RSTLOOP_SHIFT	15
60 #define SPI_PFL_CLK_RSTLOOP_MASK	(1 << SPI_PFL_CLK_RSTLOOP_SHIFT)
61 
62 /* SPI Profile Signal registers */
63 #define SPI_PFL_SIG_REG(x)		(0x100 + (0x20 * (x)) + 0x04)
64 #define SPI_PFL_SIG_LATCHRIS_SHIFT	12
65 #define SPI_PFL_SIG_LATCHRIS_MASK	(1 << SPI_PFL_SIG_LATCHRIS_SHIFT)
66 #define SPI_PFL_SIG_LAUNCHRIS_SHIFT	13
67 #define SPI_PFL_SIG_LAUNCHRIS_MASK	(1 << SPI_PFL_SIG_LAUNCHRIS_SHIFT)
68 #define SPI_PFL_SIG_ASYNCIN_SHIFT	16
69 #define SPI_PFL_SIG_ASYNCIN_MASK	(1 << SPI_PFL_SIG_ASYNCIN_SHIFT)
70 
71 /* SPI Profile Mode registers */
72 #define SPI_PFL_MODE_REG(x)		(0x100 + (0x20 * (x)) + 0x08)
73 #define SPI_PFL_MODE_FILL_SHIFT		0
74 #define SPI_PFL_MODE_FILL_MASK		(0xff << SPI_PFL_MODE_FILL_SHIFT)
75 #define SPI_PFL_MODE_MDRDSZ_SHIFT	16
76 #define SPI_PFL_MODE_MDRDSZ_MASK	(1 << SPI_PFL_MODE_MDRDSZ_SHIFT)
77 #define SPI_PFL_MODE_MDWRSZ_SHIFT	18
78 #define SPI_PFL_MODE_MDWRSZ_MASK	(1 << SPI_PFL_MODE_MDWRSZ_SHIFT)
79 #define SPI_PFL_MODE_3WIRE_SHIFT	20
80 #define SPI_PFL_MODE_3WIRE_MASK		(1 << SPI_PFL_MODE_3WIRE_SHIFT)
81 
82 /* SPI Ping-Pong FIFO registers */
83 #define HSSPI_FIFO_SIZE			0x200
84 #define HSSPI_FIFO_BASE			(0x200 + \
85 					 (HSSPI_FIFO_SIZE * HSSPI_PP))
86 
87 /* SPI Ping-Pong FIFO OP register */
88 #define HSSPI_FIFO_OP_SIZE		0x2
89 #define HSSPI_FIFO_OP_REG		(HSSPI_FIFO_BASE + 0x00)
90 #define HSSPI_FIFO_OP_BYTES_SHIFT	0
91 #define HSSPI_FIFO_OP_BYTES_MASK	(0x3ff << HSSPI_FIFO_OP_BYTES_SHIFT)
92 #define HSSPI_FIFO_OP_MBIT_SHIFT	11
93 #define HSSPI_FIFO_OP_MBIT_MASK		(1 << HSSPI_FIFO_OP_MBIT_SHIFT)
94 #define HSSPI_FIFO_OP_CODE_SHIFT	13
95 #define HSSPI_FIFO_OP_READ_WRITE	(1 << HSSPI_FIFO_OP_CODE_SHIFT)
96 #define HSSPI_FIFO_OP_CODE_W		(2 << HSSPI_FIFO_OP_CODE_SHIFT)
97 #define HSSPI_FIFO_OP_CODE_R		(3 << HSSPI_FIFO_OP_CODE_SHIFT)
98 
99 struct bcm63xx_hsspi_priv {
100 	void __iomem *regs;
101 	ulong clk_rate;
102 	uint8_t num_cs;
103 	uint8_t cs_pols;
104 	uint speed;
105 };
106 
107 static int bcm63xx_hsspi_cs_info(struct udevice *bus, uint cs,
108 			   struct spi_cs_info *info)
109 {
110 	struct bcm63xx_hsspi_priv *priv = dev_get_priv(bus);
111 
112 	if (cs >= priv->num_cs) {
113 		printf("no cs %u\n", cs);
114 		return -ENODEV;
115 	}
116 
117 	return 0;
118 }
119 
120 static int bcm63xx_hsspi_set_mode(struct udevice *bus, uint mode)
121 {
122 	struct bcm63xx_hsspi_priv *priv = dev_get_priv(bus);
123 
124 	/* clock polarity */
125 	if (mode & SPI_CPOL)
126 		setbits_be32(priv->regs + SPI_CTL_REG, SPI_CTL_CLK_POL_MASK);
127 	else
128 		clrbits_be32(priv->regs + SPI_CTL_REG, SPI_CTL_CLK_POL_MASK);
129 
130 	return 0;
131 }
132 
133 static int bcm63xx_hsspi_set_speed(struct udevice *bus, uint speed)
134 {
135 	struct bcm63xx_hsspi_priv *priv = dev_get_priv(bus);
136 
137 	priv->speed = speed;
138 
139 	return 0;
140 }
141 
142 static void bcm63xx_hsspi_activate_cs(struct bcm63xx_hsspi_priv *priv,
143 				   struct dm_spi_slave_platdata *plat)
144 {
145 	uint32_t clr, set;
146 
147 	/* profile clock */
148 	set = DIV_ROUND_UP(priv->clk_rate, priv->speed);
149 	set = DIV_ROUND_UP(2048, set);
150 	set &= SPI_PFL_CLK_FREQ_MASK;
151 	set |= SPI_PFL_CLK_RSTLOOP_MASK;
152 	writel_be(set, priv->regs + SPI_PFL_CLK_REG(plat->cs));
153 
154 	/* profile signal */
155 	set = 0;
156 	clr = SPI_PFL_SIG_LAUNCHRIS_MASK |
157 	      SPI_PFL_SIG_LATCHRIS_MASK |
158 	      SPI_PFL_SIG_ASYNCIN_MASK;
159 
160 	/* latch/launch config */
161 	if (plat->mode & SPI_CPHA)
162 		set |= SPI_PFL_SIG_LAUNCHRIS_MASK;
163 	else
164 		set |= SPI_PFL_SIG_LATCHRIS_MASK;
165 
166 	/* async clk */
167 	if (priv->speed > SPI_MAX_SYNC_CLOCK)
168 		set |= SPI_PFL_SIG_ASYNCIN_MASK;
169 
170 	clrsetbits_be32(priv->regs + SPI_PFL_SIG_REG(plat->cs), clr, set);
171 
172 	/* global control */
173 	set = 0;
174 	clr = 0;
175 
176 	/* invert cs polarity */
177 	if (priv->cs_pols & BIT(plat->cs))
178 		clr |= BIT(plat->cs);
179 	else
180 		set |= BIT(plat->cs);
181 
182 	/* invert dummy cs polarity */
183 	if (priv->cs_pols & BIT(!plat->cs))
184 		clr |= BIT(!plat->cs);
185 	else
186 		set |= BIT(!plat->cs);
187 
188 	clrsetbits_be32(priv->regs + SPI_CTL_REG, clr, set);
189 }
190 
191 static void bcm63xx_hsspi_deactivate_cs(struct bcm63xx_hsspi_priv *priv)
192 {
193 	/* restore cs polarities */
194 	clrsetbits_be32(priv->regs + SPI_CTL_REG, SPI_CTL_CS_POL_MASK,
195 			priv->cs_pols);
196 }
197 
198 /*
199  * BCM63xx HSSPI driver doesn't allow keeping CS active between transfers
200  * because they are controlled by HW.
201  * However, it provides a mechanism to prepend write transfers prior to read
202  * transfers (with a maximum prepend of 15 bytes), which is usually enough for
203  * SPI-connected flashes since reading requires prepending a write transfer of
204  * 5 bytes. On the other hand it also provides a way to invert each CS
205  * polarity, not only between transfers like the older BCM63xx SPI driver, but
206  * also the rest of the time.
207  *
208  * Instead of using the prepend mechanism, this implementation inverts the
209  * polarity of both the desired CS and another dummy CS when the bus is
210  * claimed. This way, the dummy CS is restored to its inactive value when
211  * transfers are issued and the desired CS is preserved in its active value
212  * all the time. This hack is also used in the upstream linux driver and
213  * allows keeping CS active between trasnfers even if the HW doesn't give
214  * this possibility.
215  */
216 static int bcm63xx_hsspi_xfer(struct udevice *dev, unsigned int bitlen,
217 		const void *dout, void *din, unsigned long flags)
218 {
219 	struct bcm63xx_hsspi_priv *priv = dev_get_priv(dev->parent);
220 	struct dm_spi_slave_platdata *plat = dev_get_parent_platdata(dev);
221 	size_t data_bytes = bitlen / 8;
222 	size_t step_size = HSSPI_FIFO_SIZE;
223 	uint16_t opcode = 0;
224 	uint32_t val;
225 	const uint8_t *tx = dout;
226 	uint8_t *rx = din;
227 
228 	if (flags & SPI_XFER_BEGIN)
229 		bcm63xx_hsspi_activate_cs(priv, plat);
230 
231 	/* fifo operation */
232 	if (tx && rx)
233 		opcode = HSSPI_FIFO_OP_READ_WRITE;
234 	else if (rx)
235 		opcode = HSSPI_FIFO_OP_CODE_R;
236 	else if (tx)
237 		opcode = HSSPI_FIFO_OP_CODE_W;
238 
239 	if (opcode != HSSPI_FIFO_OP_CODE_R)
240 		step_size -= HSSPI_FIFO_OP_SIZE;
241 
242 	/* dual mode */
243 	if ((opcode == HSSPI_FIFO_OP_CODE_R && plat->mode == SPI_RX_DUAL) ||
244 	    (opcode == HSSPI_FIFO_OP_CODE_W && plat->mode == SPI_TX_DUAL))
245 		opcode |= HSSPI_FIFO_OP_MBIT_MASK;
246 
247 	/* profile mode */
248 	val = SPI_PFL_MODE_FILL_MASK |
249 	      SPI_PFL_MODE_MDRDSZ_MASK |
250 	      SPI_PFL_MODE_MDWRSZ_MASK;
251 	if (plat->mode & SPI_3WIRE)
252 		val |= SPI_PFL_MODE_3WIRE_MASK;
253 	writel_be(val, priv->regs + SPI_PFL_MODE_REG(plat->cs));
254 
255 	/* transfer loop */
256 	while (data_bytes > 0) {
257 		size_t curr_step = min(step_size, data_bytes);
258 		int ret;
259 
260 		/* copy tx data */
261 		if (tx) {
262 			memcpy_toio(priv->regs + HSSPI_FIFO_BASE +
263 				    HSSPI_FIFO_OP_SIZE, tx, curr_step);
264 			tx += curr_step;
265 		}
266 
267 		/* set fifo operation */
268 		writew_be(opcode | (curr_step & HSSPI_FIFO_OP_BYTES_MASK),
269 			  priv->regs + HSSPI_FIFO_OP_REG);
270 
271 		/* issue the transfer */
272 		val = SPI_CMD_OP_START;
273 		val |= (plat->cs << SPI_CMD_PFL_SHIFT) &
274 		       SPI_CMD_PFL_MASK;
275 		val |= (!plat->cs << SPI_CMD_SLAVE_SHIFT) &
276 		       SPI_CMD_SLAVE_MASK;
277 		writel_be(val, priv->regs + SPI_CMD_REG);
278 
279 		/* wait for completion */
280 		ret = wait_for_bit_be32(priv->regs + SPI_STAT_REG,
281 					SPI_STAT_SRCBUSY_MASK, false,
282 					1000, false);
283 		if (ret) {
284 			printf("interrupt timeout\n");
285 			return ret;
286 		}
287 
288 		/* copy rx data */
289 		if (rx) {
290 			memcpy_fromio(rx, priv->regs + HSSPI_FIFO_BASE,
291 				      curr_step);
292 			rx += curr_step;
293 		}
294 
295 		data_bytes -= curr_step;
296 	}
297 
298 	if (flags & SPI_XFER_END)
299 		bcm63xx_hsspi_deactivate_cs(priv);
300 
301 	return 0;
302 }
303 
304 static const struct dm_spi_ops bcm63xx_hsspi_ops = {
305 	.cs_info = bcm63xx_hsspi_cs_info,
306 	.set_mode = bcm63xx_hsspi_set_mode,
307 	.set_speed = bcm63xx_hsspi_set_speed,
308 	.xfer = bcm63xx_hsspi_xfer,
309 };
310 
311 static const struct udevice_id bcm63xx_hsspi_ids[] = {
312 	{ .compatible = "brcm,bcm6328-hsspi", },
313 	{ /* sentinel */ }
314 };
315 
316 static int bcm63xx_hsspi_child_pre_probe(struct udevice *dev)
317 {
318 	struct bcm63xx_hsspi_priv *priv = dev_get_priv(dev->parent);
319 	struct dm_spi_slave_platdata *plat = dev_get_parent_platdata(dev);
320 
321 	/* check cs */
322 	if (plat->cs >= priv->num_cs) {
323 		printf("no cs %u\n", plat->cs);
324 		return -ENODEV;
325 	}
326 
327 	/* cs polarity */
328 	if (plat->mode & SPI_CS_HIGH)
329 		priv->cs_pols |= BIT(plat->cs);
330 	else
331 		priv->cs_pols &= ~BIT(plat->cs);
332 
333 	return 0;
334 }
335 
336 static int bcm63xx_hsspi_probe(struct udevice *dev)
337 {
338 	struct bcm63xx_hsspi_priv *priv = dev_get_priv(dev);
339 	struct reset_ctl rst_ctl;
340 	struct clk clk;
341 	fdt_addr_t addr;
342 	fdt_size_t size;
343 	int ret;
344 
345 	addr = devfdt_get_addr_size_index(dev, 0, &size);
346 	if (addr == FDT_ADDR_T_NONE)
347 		return -EINVAL;
348 
349 	priv->regs = ioremap(addr, size);
350 	priv->num_cs = fdtdec_get_uint(gd->fdt_blob, dev_of_offset(dev),
351 				       "num-cs", 8);
352 
353 	/* enable clock */
354 	ret = clk_get_by_name(dev, "hsspi", &clk);
355 	if (ret < 0)
356 		return ret;
357 
358 	ret = clk_enable(&clk);
359 	if (ret < 0)
360 		return ret;
361 
362 	ret = clk_free(&clk);
363 	if (ret < 0)
364 		return ret;
365 
366 	/* get clock rate */
367 	ret = clk_get_by_name(dev, "pll", &clk);
368 	if (ret < 0)
369 		return ret;
370 
371 	priv->clk_rate = clk_get_rate(&clk);
372 
373 	ret = clk_free(&clk);
374 	if (ret < 0)
375 		return ret;
376 
377 	/* perform reset */
378 	ret = reset_get_by_index(dev, 0, &rst_ctl);
379 	if (ret < 0)
380 		return ret;
381 
382 	ret = reset_deassert(&rst_ctl);
383 	if (ret < 0)
384 		return ret;
385 
386 	ret = reset_free(&rst_ctl);
387 	if (ret < 0)
388 		return ret;
389 
390 	/* initialize hardware */
391 	writel_be(0, priv->regs + SPI_IR_MASK_REG);
392 
393 	/* clear pending interrupts */
394 	writel_be(SPI_IR_CLEAR_ALL, priv->regs + SPI_IR_STAT_REG);
395 
396 	/* enable clk gate */
397 	setbits_be32(priv->regs + SPI_CTL_REG, SPI_CTL_CLK_GATE_MASK);
398 
399 	/* read default cs polarities */
400 	priv->cs_pols = readl_be(priv->regs + SPI_CTL_REG) &
401 			SPI_CTL_CS_POL_MASK;
402 
403 	return 0;
404 }
405 
406 U_BOOT_DRIVER(bcm63xx_hsspi) = {
407 	.name = "bcm63xx_hsspi",
408 	.id = UCLASS_SPI,
409 	.of_match = bcm63xx_hsspi_ids,
410 	.ops = &bcm63xx_hsspi_ops,
411 	.priv_auto_alloc_size = sizeof(struct bcm63xx_hsspi_priv),
412 	.child_pre_probe = bcm63xx_hsspi_child_pre_probe,
413 	.probe = bcm63xx_hsspi_probe,
414 };
415