xref: /openbmc/u-boot/drivers/spi/bcm63xx_hsspi.c (revision 85187b80)
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 DECLARE_GLOBAL_DATA_PTR;
19 
20 #define HSSPI_PP			0
21 
22 #define SPI_MAX_SYNC_CLOCK		30000000
23 
24 /* SPI Control register */
25 #define SPI_CTL_REG			0x000
26 #define SPI_CTL_CS_POL_SHIFT		0
27 #define SPI_CTL_CS_POL_MASK		(0xff << SPI_CTL_CS_POL_SHIFT)
28 #define SPI_CTL_CLK_GATE_SHIFT		16
29 #define SPI_CTL_CLK_GATE_MASK		(1 << SPI_CTL_CLK_GATE_SHIFT)
30 #define SPI_CTL_CLK_POL_SHIFT		17
31 #define SPI_CTL_CLK_POL_MASK		(1 << SPI_CTL_CLK_POL_SHIFT)
32 
33 /* SPI Interrupts registers */
34 #define SPI_IR_STAT_REG			0x008
35 #define SPI_IR_ST_MASK_REG		0x00c
36 #define SPI_IR_MASK_REG			0x010
37 
38 #define SPI_IR_CLEAR_ALL		0xff001f1f
39 
40 /* SPI Ping-Pong Command registers */
41 #define SPI_CMD_REG			(0x080 + (0x40 * (HSSPI_PP)) + 0x00)
42 #define SPI_CMD_OP_SHIFT		0
43 #define SPI_CMD_OP_START		(0x1 << SPI_CMD_OP_SHIFT)
44 #define SPI_CMD_PFL_SHIFT		8
45 #define SPI_CMD_PFL_MASK		(0x7 << SPI_CMD_PFL_SHIFT)
46 #define SPI_CMD_SLAVE_SHIFT		12
47 #define SPI_CMD_SLAVE_MASK		(0x7 << SPI_CMD_SLAVE_SHIFT)
48 
49 /* SPI Ping-Pong Status registers */
50 #define SPI_STAT_REG			(0x080 + (0x40 * (HSSPI_PP)) + 0x04)
51 #define SPI_STAT_SRCBUSY_SHIFT		1
52 #define SPI_STAT_SRCBUSY_MASK		(1 << SPI_STAT_SRCBUSY_SHIFT)
53 
54 /* SPI Profile Clock registers */
55 #define SPI_PFL_CLK_REG(x)		(0x100 + (0x20 * (x)) + 0x00)
56 #define SPI_PFL_CLK_FREQ_SHIFT		0
57 #define SPI_PFL_CLK_FREQ_MASK		(0x3fff << SPI_PFL_CLK_FREQ_SHIFT)
58 #define SPI_PFL_CLK_RSTLOOP_SHIFT	15
59 #define SPI_PFL_CLK_RSTLOOP_MASK	(1 << SPI_PFL_CLK_RSTLOOP_SHIFT)
60 
61 /* SPI Profile Signal registers */
62 #define SPI_PFL_SIG_REG(x)		(0x100 + (0x20 * (x)) + 0x04)
63 #define SPI_PFL_SIG_LATCHRIS_SHIFT	12
64 #define SPI_PFL_SIG_LATCHRIS_MASK	(1 << SPI_PFL_SIG_LATCHRIS_SHIFT)
65 #define SPI_PFL_SIG_LAUNCHRIS_SHIFT	13
66 #define SPI_PFL_SIG_LAUNCHRIS_MASK	(1 << SPI_PFL_SIG_LAUNCHRIS_SHIFT)
67 #define SPI_PFL_SIG_ASYNCIN_SHIFT	16
68 #define SPI_PFL_SIG_ASYNCIN_MASK	(1 << SPI_PFL_SIG_ASYNCIN_SHIFT)
69 
70 /* SPI Profile Mode registers */
71 #define SPI_PFL_MODE_REG(x)		(0x100 + (0x20 * (x)) + 0x08)
72 #define SPI_PFL_MODE_FILL_SHIFT		0
73 #define SPI_PFL_MODE_FILL_MASK		(0xff << SPI_PFL_MODE_FILL_SHIFT)
74 #define SPI_PFL_MODE_MDRDSZ_SHIFT	16
75 #define SPI_PFL_MODE_MDRDSZ_MASK	(1 << SPI_PFL_MODE_MDRDSZ_SHIFT)
76 #define SPI_PFL_MODE_MDWRSZ_SHIFT	18
77 #define SPI_PFL_MODE_MDWRSZ_MASK	(1 << SPI_PFL_MODE_MDWRSZ_SHIFT)
78 #define SPI_PFL_MODE_3WIRE_SHIFT	20
79 #define SPI_PFL_MODE_3WIRE_MASK		(1 << SPI_PFL_MODE_3WIRE_SHIFT)
80 
81 /* SPI Ping-Pong FIFO registers */
82 #define HSSPI_FIFO_SIZE			0x200
83 #define HSSPI_FIFO_BASE			(0x200 + \
84 					 (HSSPI_FIFO_SIZE * HSSPI_PP))
85 
86 /* SPI Ping-Pong FIFO OP register */
87 #define HSSPI_FIFO_OP_SIZE		0x2
88 #define HSSPI_FIFO_OP_REG		(HSSPI_FIFO_BASE + 0x00)
89 #define HSSPI_FIFO_OP_BYTES_SHIFT	0
90 #define HSSPI_FIFO_OP_BYTES_MASK	(0x3ff << HSSPI_FIFO_OP_BYTES_SHIFT)
91 #define HSSPI_FIFO_OP_MBIT_SHIFT	11
92 #define HSSPI_FIFO_OP_MBIT_MASK		(1 << HSSPI_FIFO_OP_MBIT_SHIFT)
93 #define HSSPI_FIFO_OP_CODE_SHIFT	13
94 #define HSSPI_FIFO_OP_READ_WRITE	(1 << HSSPI_FIFO_OP_CODE_SHIFT)
95 #define HSSPI_FIFO_OP_CODE_W		(2 << HSSPI_FIFO_OP_CODE_SHIFT)
96 #define HSSPI_FIFO_OP_CODE_R		(3 << HSSPI_FIFO_OP_CODE_SHIFT)
97 
98 struct bcm63xx_hsspi_priv {
99 	void __iomem *regs;
100 	ulong clk_rate;
101 	uint8_t num_cs;
102 	uint8_t cs_pols;
103 	uint speed;
104 };
105 
106 static int bcm63xx_hsspi_cs_info(struct udevice *bus, uint cs,
107 			   struct spi_cs_info *info)
108 {
109 	struct bcm63xx_hsspi_priv *priv = dev_get_priv(bus);
110 
111 	if (cs >= priv->num_cs) {
112 		printf("no cs %u\n", cs);
113 		return -ENODEV;
114 	}
115 
116 	return 0;
117 }
118 
119 static int bcm63xx_hsspi_set_mode(struct udevice *bus, uint mode)
120 {
121 	struct bcm63xx_hsspi_priv *priv = dev_get_priv(bus);
122 
123 	/* clock polarity */
124 	if (mode & SPI_CPOL)
125 		setbits_be32(priv->regs + SPI_CTL_REG, SPI_CTL_CLK_POL_MASK);
126 	else
127 		clrbits_be32(priv->regs + SPI_CTL_REG, SPI_CTL_CLK_POL_MASK);
128 
129 	return 0;
130 }
131 
132 static int bcm63xx_hsspi_set_speed(struct udevice *bus, uint speed)
133 {
134 	struct bcm63xx_hsspi_priv *priv = dev_get_priv(bus);
135 
136 	priv->speed = speed;
137 
138 	return 0;
139 }
140 
141 static void bcm63xx_hsspi_activate_cs(struct bcm63xx_hsspi_priv *priv,
142 				   struct dm_spi_slave_platdata *plat)
143 {
144 	uint32_t clr, set;
145 
146 	/* profile clock */
147 	set = DIV_ROUND_UP(priv->clk_rate, priv->speed);
148 	set = DIV_ROUND_UP(2048, set);
149 	set &= SPI_PFL_CLK_FREQ_MASK;
150 	set |= SPI_PFL_CLK_RSTLOOP_MASK;
151 	writel_be(set, priv->regs + SPI_PFL_CLK_REG(plat->cs));
152 
153 	/* profile signal */
154 	set = 0;
155 	clr = SPI_PFL_SIG_LAUNCHRIS_MASK |
156 	      SPI_PFL_SIG_LATCHRIS_MASK |
157 	      SPI_PFL_SIG_ASYNCIN_MASK;
158 
159 	/* latch/launch config */
160 	if (plat->mode & SPI_CPHA)
161 		set |= SPI_PFL_SIG_LAUNCHRIS_MASK;
162 	else
163 		set |= SPI_PFL_SIG_LATCHRIS_MASK;
164 
165 	/* async clk */
166 	if (priv->speed > SPI_MAX_SYNC_CLOCK)
167 		set |= SPI_PFL_SIG_ASYNCIN_MASK;
168 
169 	clrsetbits_be32(priv->regs + SPI_PFL_SIG_REG(plat->cs), clr, set);
170 
171 	/* global control */
172 	set = 0;
173 	clr = 0;
174 
175 	/* invert cs polarity */
176 	if (priv->cs_pols & BIT(plat->cs))
177 		clr |= BIT(plat->cs);
178 	else
179 		set |= BIT(plat->cs);
180 
181 	/* invert dummy cs polarity */
182 	if (priv->cs_pols & BIT(!plat->cs))
183 		clr |= BIT(!plat->cs);
184 	else
185 		set |= BIT(!plat->cs);
186 
187 	clrsetbits_be32(priv->regs + SPI_CTL_REG, clr, set);
188 }
189 
190 static void bcm63xx_hsspi_deactivate_cs(struct bcm63xx_hsspi_priv *priv)
191 {
192 	/* restore cs polarities */
193 	clrsetbits_be32(priv->regs + SPI_CTL_REG, SPI_CTL_CS_POL_MASK,
194 			priv->cs_pols);
195 }
196 
197 /*
198  * BCM63xx HSSPI driver doesn't allow keeping CS active between transfers
199  * because they are controlled by HW.
200  * However, it provides a mechanism to prepend write transfers prior to read
201  * transfers (with a maximum prepend of 15 bytes), which is usually enough for
202  * SPI-connected flashes since reading requires prepending a write transfer of
203  * 5 bytes. On the other hand it also provides a way to invert each CS
204  * polarity, not only between transfers like the older BCM63xx SPI driver, but
205  * also the rest of the time.
206  *
207  * Instead of using the prepend mechanism, this implementation inverts the
208  * polarity of both the desired CS and another dummy CS when the bus is
209  * claimed. This way, the dummy CS is restored to its inactive value when
210  * transfers are issued and the desired CS is preserved in its active value
211  * all the time. This hack is also used in the upstream linux driver and
212  * allows keeping CS active between trasnfers even if the HW doesn't give
213  * this possibility.
214  */
215 static int bcm63xx_hsspi_xfer(struct udevice *dev, unsigned int bitlen,
216 		const void *dout, void *din, unsigned long flags)
217 {
218 	struct bcm63xx_hsspi_priv *priv = dev_get_priv(dev->parent);
219 	struct dm_spi_slave_platdata *plat = dev_get_parent_platdata(dev);
220 	size_t data_bytes = bitlen / 8;
221 	size_t step_size = HSSPI_FIFO_SIZE;
222 	uint16_t opcode = 0;
223 	uint32_t val;
224 	const uint8_t *tx = dout;
225 	uint8_t *rx = din;
226 
227 	if (flags & SPI_XFER_BEGIN)
228 		bcm63xx_hsspi_activate_cs(priv, plat);
229 
230 	/* fifo operation */
231 	if (tx && rx)
232 		opcode = HSSPI_FIFO_OP_READ_WRITE;
233 	else if (rx)
234 		opcode = HSSPI_FIFO_OP_CODE_R;
235 	else if (tx)
236 		opcode = HSSPI_FIFO_OP_CODE_W;
237 
238 	if (opcode != HSSPI_FIFO_OP_CODE_R)
239 		step_size -= HSSPI_FIFO_OP_SIZE;
240 
241 	/* dual mode */
242 	if ((opcode == HSSPI_FIFO_OP_CODE_R && plat->mode == SPI_RX_DUAL) ||
243 	    (opcode == HSSPI_FIFO_OP_CODE_W && plat->mode == SPI_TX_DUAL))
244 		opcode |= HSSPI_FIFO_OP_MBIT_MASK;
245 
246 	/* profile mode */
247 	val = SPI_PFL_MODE_FILL_MASK |
248 	      SPI_PFL_MODE_MDRDSZ_MASK |
249 	      SPI_PFL_MODE_MDWRSZ_MASK;
250 	if (plat->mode & SPI_3WIRE)
251 		val |= SPI_PFL_MODE_3WIRE_MASK;
252 	writel_be(val, priv->regs + SPI_PFL_MODE_REG(plat->cs));
253 
254 	/* transfer loop */
255 	while (data_bytes > 0) {
256 		size_t curr_step = min(step_size, data_bytes);
257 		int ret;
258 
259 		/* copy tx data */
260 		if (tx) {
261 			memcpy_toio(priv->regs + HSSPI_FIFO_BASE +
262 				    HSSPI_FIFO_OP_SIZE, tx, curr_step);
263 			tx += curr_step;
264 		}
265 
266 		/* set fifo operation */
267 		writew_be(opcode | (curr_step & HSSPI_FIFO_OP_BYTES_MASK),
268 			  priv->regs + HSSPI_FIFO_OP_REG);
269 
270 		/* issue the transfer */
271 		val = SPI_CMD_OP_START;
272 		val |= (plat->cs << SPI_CMD_PFL_SHIFT) &
273 		       SPI_CMD_PFL_MASK;
274 		val |= (!plat->cs << SPI_CMD_SLAVE_SHIFT) &
275 		       SPI_CMD_SLAVE_MASK;
276 		writel_be(val, priv->regs + SPI_CMD_REG);
277 
278 		/* wait for completion */
279 		ret = wait_for_bit_be32(priv->regs + SPI_STAT_REG,
280 					SPI_STAT_SRCBUSY_MASK, false,
281 					1000, false);
282 		if (ret) {
283 			printf("interrupt timeout\n");
284 			return ret;
285 		}
286 
287 		/* copy rx data */
288 		if (rx) {
289 			memcpy_fromio(rx, priv->regs + HSSPI_FIFO_BASE,
290 				      curr_step);
291 			rx += curr_step;
292 		}
293 
294 		data_bytes -= curr_step;
295 	}
296 
297 	if (flags & SPI_XFER_END)
298 		bcm63xx_hsspi_deactivate_cs(priv);
299 
300 	return 0;
301 }
302 
303 static const struct dm_spi_ops bcm63xx_hsspi_ops = {
304 	.cs_info = bcm63xx_hsspi_cs_info,
305 	.set_mode = bcm63xx_hsspi_set_mode,
306 	.set_speed = bcm63xx_hsspi_set_speed,
307 	.xfer = bcm63xx_hsspi_xfer,
308 };
309 
310 static const struct udevice_id bcm63xx_hsspi_ids[] = {
311 	{ .compatible = "brcm,bcm6328-hsspi", },
312 	{ /* sentinel */ }
313 };
314 
315 static int bcm63xx_hsspi_child_pre_probe(struct udevice *dev)
316 {
317 	struct bcm63xx_hsspi_priv *priv = dev_get_priv(dev->parent);
318 	struct dm_spi_slave_platdata *plat = dev_get_parent_platdata(dev);
319 
320 	/* check cs */
321 	if (plat->cs >= priv->num_cs) {
322 		printf("no cs %u\n", plat->cs);
323 		return -ENODEV;
324 	}
325 
326 	/* cs polarity */
327 	if (plat->mode & SPI_CS_HIGH)
328 		priv->cs_pols |= BIT(plat->cs);
329 	else
330 		priv->cs_pols &= ~BIT(plat->cs);
331 
332 	return 0;
333 }
334 
335 static int bcm63xx_hsspi_probe(struct udevice *dev)
336 {
337 	struct bcm63xx_hsspi_priv *priv = dev_get_priv(dev);
338 	struct reset_ctl rst_ctl;
339 	struct clk clk;
340 	fdt_addr_t addr;
341 	fdt_size_t size;
342 	int ret;
343 
344 	addr = devfdt_get_addr_size_index(dev, 0, &size);
345 	if (addr == FDT_ADDR_T_NONE)
346 		return -EINVAL;
347 
348 	priv->regs = ioremap(addr, size);
349 	priv->num_cs = fdtdec_get_uint(gd->fdt_blob, dev_of_offset(dev),
350 				       "num-cs", 8);
351 
352 	/* enable clock */
353 	ret = clk_get_by_name(dev, "hsspi", &clk);
354 	if (ret < 0)
355 		return ret;
356 
357 	ret = clk_enable(&clk);
358 	if (ret < 0)
359 		return ret;
360 
361 	ret = clk_free(&clk);
362 	if (ret < 0)
363 		return ret;
364 
365 	/* get clock rate */
366 	ret = clk_get_by_name(dev, "pll", &clk);
367 	if (ret < 0)
368 		return ret;
369 
370 	priv->clk_rate = clk_get_rate(&clk);
371 
372 	ret = clk_free(&clk);
373 	if (ret < 0)
374 		return ret;
375 
376 	/* perform reset */
377 	ret = reset_get_by_index(dev, 0, &rst_ctl);
378 	if (ret < 0)
379 		return ret;
380 
381 	ret = reset_deassert(&rst_ctl);
382 	if (ret < 0)
383 		return ret;
384 
385 	ret = reset_free(&rst_ctl);
386 	if (ret < 0)
387 		return ret;
388 
389 	/* initialize hardware */
390 	writel_be(0, priv->regs + SPI_IR_MASK_REG);
391 
392 	/* clear pending interrupts */
393 	writel_be(SPI_IR_CLEAR_ALL, priv->regs + SPI_IR_STAT_REG);
394 
395 	/* enable clk gate */
396 	setbits_be32(priv->regs + SPI_CTL_REG, SPI_CTL_CLK_GATE_MASK);
397 
398 	/* read default cs polarities */
399 	priv->cs_pols = readl_be(priv->regs + SPI_CTL_REG) &
400 			SPI_CTL_CS_POL_MASK;
401 
402 	return 0;
403 }
404 
405 U_BOOT_DRIVER(bcm63xx_hsspi) = {
406 	.name = "bcm63xx_hsspi",
407 	.id = UCLASS_SPI,
408 	.of_match = bcm63xx_hsspi_ids,
409 	.ops = &bcm63xx_hsspi_ops,
410 	.priv_auto_alloc_size = sizeof(struct bcm63xx_hsspi_priv),
411 	.child_pre_probe = bcm63xx_hsspi_child_pre_probe,
412 	.probe = bcm63xx_hsspi_probe,
413 };
414