xref: /openbmc/u-boot/drivers/spi/atcspi200_spi.c (revision 8ee59472)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Andestech ATCSPI200 SPI controller driver.
4  *
5  * Copyright 2017 Andes Technology, Inc.
6  * Author: Rick Chen (rick@andestech.com)
7  */
8 
9 #include <clk.h>
10 #include <common.h>
11 #include <malloc.h>
12 #include <spi.h>
13 #include <asm/io.h>
14 #include <dm.h>
15 
16 DECLARE_GLOBAL_DATA_PTR;
17 
18 #define MAX_TRANSFER_LEN	512
19 #define CHUNK_SIZE		1
20 #define SPI_TIMEOUT		0x100000
21 #define SPI0_BUS		0
22 #define SPI1_BUS		1
23 #define SPI0_BASE		0xf0b00000
24 #define SPI1_BASE		0xf0f00000
25 #define NSPI_MAX_CS_NUM		1
26 
27 struct atcspi200_spi_regs {
28 	u32	rev;
29 	u32	reserve1[3];
30 	u32	format;		/* 0x10 */
31 #define DATA_LENGTH(x)	((x-1)<<8)
32 	u32	pio;
33 	u32	reserve2[2];
34 	u32	tctrl;		/* 0x20 */
35 #define TRAMODE_OFFSET	24
36 #define TRAMODE_MASK	(0x0F<<TRAMODE_OFFSET)
37 #define TRAMODE_WR_SYNC	(0<<TRAMODE_OFFSET)
38 #define TRAMODE_WO	(1<<TRAMODE_OFFSET)
39 #define TRAMODE_RO	(2<<TRAMODE_OFFSET)
40 #define TRAMODE_WR	(3<<TRAMODE_OFFSET)
41 #define TRAMODE_RW	(4<<TRAMODE_OFFSET)
42 #define TRAMODE_WDR	(5<<TRAMODE_OFFSET)
43 #define TRAMODE_RDW	(6<<TRAMODE_OFFSET)
44 #define TRAMODE_NONE	(7<<TRAMODE_OFFSET)
45 #define TRAMODE_DW	(8<<TRAMODE_OFFSET)
46 #define TRAMODE_DR	(9<<TRAMODE_OFFSET)
47 #define WCNT_OFFSET	12
48 #define WCNT_MASK	(0x1FF<<WCNT_OFFSET)
49 #define RCNT_OFFSET	0
50 #define RCNT_MASK	(0x1FF<<RCNT_OFFSET)
51 	u32	cmd;
52 	u32	addr;
53 	u32	data;
54 	u32	ctrl;		/* 0x30 */
55 #define TXFTH_OFFSET	16
56 #define RXFTH_OFFSET	8
57 #define TXDMAEN		(1<<4)
58 #define RXDMAEN		(1<<3)
59 #define TXFRST		(1<<2)
60 #define RXFRST		(1<<1)
61 #define SPIRST		(1<<0)
62 	u32	status;
63 #define TXFFL		(1<<23)
64 #define TXEPTY		(1<<22)
65 #define TXFVE_MASK	(0x1F<<16)
66 #define RXFEM		(1<<14)
67 #define RXFVE_OFFSET	(8)
68 #define RXFVE_MASK	(0x1F<<RXFVE_OFFSET)
69 #define SPIBSY		(1<<0)
70 	u32	inten;
71 	u32	intsta;
72 	u32	timing;		/* 0x40 */
73 #define SCLK_DIV_MASK	0xFF
74 };
75 
76 struct nds_spi_slave {
77 	volatile struct atcspi200_spi_regs *regs;
78 	int		to;
79 	unsigned int	freq;
80 	ulong		clock;
81 	unsigned int	mode;
82 	u8 		num_cs;
83 	unsigned int	mtiming;
84 	size_t		cmd_len;
85 	u8		cmd_buf[16];
86 	size_t		data_len;
87 	size_t		tran_len;
88 	u8		*din;
89 	u8		*dout;
90 	unsigned int    max_transfer_length;
91 };
92 
93 static int __atcspi200_spi_set_speed(struct nds_spi_slave *ns)
94 {
95 	u32 tm;
96 	u8 div;
97 	tm = ns->regs->timing;
98 	tm &= ~SCLK_DIV_MASK;
99 
100 	if(ns->freq >= ns->clock)
101 		div =0xff;
102 	else{
103 		for (div = 0; div < 0xff; div++) {
104 			if (ns->freq >= ns->clock / (2 * (div + 1)))
105 				break;
106 		}
107 	}
108 
109 	tm |= div;
110 	ns->regs->timing = tm;
111 
112 	return 0;
113 
114 }
115 
116 static int __atcspi200_spi_claim_bus(struct nds_spi_slave *ns)
117 {
118 		unsigned int format=0;
119 		ns->regs->ctrl |= (TXFRST|RXFRST|SPIRST);
120 		while((ns->regs->ctrl &(TXFRST|RXFRST|SPIRST))&&(ns->to--))
121 			if(!ns->to)
122 				return -EINVAL;
123 
124 		ns->cmd_len = 0;
125 		format = ns->mode|DATA_LENGTH(8);
126 		ns->regs->format = format;
127 		__atcspi200_spi_set_speed(ns);
128 
129 		return 0;
130 }
131 
132 static int __atcspi200_spi_release_bus(struct nds_spi_slave *ns)
133 {
134 	/* do nothing */
135 	return 0;
136 }
137 
138 static int __atcspi200_spi_start(struct nds_spi_slave *ns)
139 {
140 	int i,olen=0;
141 	int tc = ns->regs->tctrl;
142 
143 	tc &= ~(WCNT_MASK|RCNT_MASK|TRAMODE_MASK);
144 	if ((ns->din)&&(ns->cmd_len))
145 		tc |= TRAMODE_WR;
146 	else if (ns->din)
147 		tc |= TRAMODE_RO;
148 	else
149 		tc |= TRAMODE_WO;
150 
151 	if(ns->dout)
152 		olen = ns->tran_len;
153 	tc |= (ns->cmd_len+olen-1) << WCNT_OFFSET;
154 
155 	if(ns->din)
156 		tc |= (ns->tran_len-1) << RCNT_OFFSET;
157 
158 	ns->regs->tctrl = tc;
159 	ns->regs->cmd = 1;
160 
161 	for (i=0;i<ns->cmd_len;i++)
162 		ns->regs->data = ns->cmd_buf[i];
163 
164 	return 0;
165 }
166 
167 static int __atcspi200_spi_stop(struct nds_spi_slave *ns)
168 {
169 	ns->regs->timing = ns->mtiming;
170 	while ((ns->regs->status & SPIBSY)&&(ns->to--))
171 		if (!ns->to)
172 			return -EINVAL;
173 
174 	return 0;
175 }
176 
177 static void __nspi_espi_tx(struct nds_spi_slave *ns, const void *dout)
178 {
179 	ns->regs->data = *(u8 *)dout;
180 }
181 
182 static int __nspi_espi_rx(struct nds_spi_slave *ns, void *din, unsigned int bytes)
183 {
184 	*(u8 *)din = ns->regs->data;
185 	return bytes;
186 }
187 
188 
189 static int __atcspi200_spi_xfer(struct nds_spi_slave *ns,
190 		unsigned int bitlen,  const void *data_out, void *data_in,
191 		unsigned long flags)
192 {
193 		unsigned int event, rx_bytes;
194 		const void *dout = NULL;
195 		void *din = NULL;
196 		int num_blks, num_chunks, max_tran_len, tran_len;
197 		int num_bytes;
198 		u8 *cmd_buf = ns->cmd_buf;
199 		size_t cmd_len = ns->cmd_len;
200 		size_t data_len = bitlen / 8;
201 		int rf_cnt;
202 		int ret = 0;
203 
204 		max_tran_len = ns->max_transfer_length;
205 		switch (flags) {
206 		case SPI_XFER_BEGIN:
207 			cmd_len = ns->cmd_len = data_len;
208 			memcpy(cmd_buf, data_out, cmd_len);
209 			return 0;
210 
211 		case 0:
212 		case SPI_XFER_END:
213 			if (bitlen == 0) {
214 				return 0;
215 			}
216 			ns->data_len = data_len;
217 			ns->din = (u8 *)data_in;
218 			ns->dout = (u8 *)data_out;
219 			break;
220 
221 		case SPI_XFER_BEGIN | SPI_XFER_END:
222 			ns->data_len = 0;
223 			ns->din = 0;
224 			ns->dout = 0;
225 			cmd_len = ns->cmd_len = data_len;
226 			memcpy(cmd_buf, data_out, cmd_len);
227 			data_out = 0;
228 			data_len = 0;
229 			__atcspi200_spi_start(ns);
230 			break;
231 		}
232 		debug("spi_xfer: data_out %08X(%p) data_in %08X(%p) data_len %u\n",
233 		      *(uint *)data_out, data_out, *(uint *)data_in, data_in, data_len);
234 		num_chunks = DIV_ROUND_UP(data_len, max_tran_len);
235 		din = data_in;
236 		dout = data_out;
237 		while (num_chunks--) {
238 			tran_len = min(data_len, (size_t)max_tran_len);
239 			ns->tran_len = tran_len;
240 			num_blks = DIV_ROUND_UP(tran_len , CHUNK_SIZE);
241 			num_bytes = (tran_len) % CHUNK_SIZE;
242 			if(num_bytes == 0)
243 				num_bytes = CHUNK_SIZE;
244 			__atcspi200_spi_start(ns);
245 
246 			while (num_blks) {
247 				event = in_le32(&ns->regs->status);
248 				if ((event & TXEPTY) && (data_out)) {
249 					__nspi_espi_tx(ns, dout);
250 					num_blks -= CHUNK_SIZE;
251 					dout += CHUNK_SIZE;
252 				}
253 
254 				if ((event & RXFVE_MASK) && (data_in)) {
255 					rf_cnt = ((event & RXFVE_MASK)>> RXFVE_OFFSET);
256 					if (rf_cnt >= CHUNK_SIZE)
257 						rx_bytes = CHUNK_SIZE;
258 					else if (num_blks == 1 && rf_cnt == num_bytes)
259 						rx_bytes = num_bytes;
260 					else
261 						continue;
262 
263 					if (__nspi_espi_rx(ns, din, rx_bytes) == rx_bytes) {
264 						num_blks -= CHUNK_SIZE;
265 						din = (unsigned char *)din + rx_bytes;
266 					}
267 				}
268 			}
269 
270 			data_len -= tran_len;
271 			if(data_len)
272 			{
273 				ns->cmd_buf[1] += ((tran_len>>16)&0xff);
274 				ns->cmd_buf[2] += ((tran_len>>8)&0xff);
275 				ns->cmd_buf[3] += ((tran_len)&0xff);
276 				ns->data_len = data_len;
277 			}
278 			ret = __atcspi200_spi_stop(ns);
279 		}
280 		ret = __atcspi200_spi_stop(ns);
281 
282 		return ret;
283 }
284 
285 static int atcspi200_spi_set_speed(struct udevice *bus, uint max_hz)
286 {
287 	struct nds_spi_slave *ns = dev_get_priv(bus);
288 
289 	debug("%s speed %u\n", __func__, max_hz);
290 
291 	ns->freq = max_hz;
292 	__atcspi200_spi_set_speed(ns);
293 
294 	return 0;
295 }
296 
297 static int atcspi200_spi_set_mode(struct udevice *bus, uint mode)
298 {
299 	struct nds_spi_slave *ns = dev_get_priv(bus);
300 
301 	debug("%s mode %u\n", __func__, mode);
302 	ns->mode = mode;
303 
304 	return 0;
305 }
306 
307 static int atcspi200_spi_claim_bus(struct udevice *dev)
308 {
309 	struct dm_spi_slave_platdata *slave_plat =
310 		dev_get_parent_platdata(dev);
311 	struct udevice *bus = dev->parent;
312 	struct nds_spi_slave *ns = dev_get_priv(bus);
313 
314 	if (slave_plat->cs >= ns->num_cs) {
315 		printf("Invalid SPI chipselect\n");
316 		return -EINVAL;
317 	}
318 
319 	return __atcspi200_spi_claim_bus(ns);
320 }
321 
322 static int atcspi200_spi_release_bus(struct udevice *dev)
323 {
324 	struct nds_spi_slave *ns = dev_get_priv(dev->parent);
325 
326 	return __atcspi200_spi_release_bus(ns);
327 }
328 
329 static int atcspi200_spi_xfer(struct udevice *dev, unsigned int bitlen,
330 			    const void *dout, void *din,
331 			    unsigned long flags)
332 {
333 	struct udevice *bus = dev->parent;
334 	struct nds_spi_slave *ns = dev_get_priv(bus);
335 
336 	return __atcspi200_spi_xfer(ns, bitlen, dout, din, flags);
337 }
338 
339 static int atcspi200_spi_get_clk(struct udevice *bus)
340 {
341 	struct nds_spi_slave *ns = dev_get_priv(bus);
342 	struct clk clk;
343 	ulong clk_rate;
344 	int ret;
345 
346 	ret = clk_get_by_index(bus, 0, &clk);
347 	if (ret)
348 		return -EINVAL;
349 
350 	clk_rate = clk_get_rate(&clk);
351 	if (!clk_rate)
352 		return -EINVAL;
353 
354 	ns->clock = clk_rate;
355 	clk_free(&clk);
356 
357 	return 0;
358 }
359 
360 static int atcspi200_spi_probe(struct udevice *bus)
361 {
362 	struct nds_spi_slave *ns = dev_get_priv(bus);
363 
364 	ns->to = SPI_TIMEOUT;
365 	ns->max_transfer_length = MAX_TRANSFER_LEN;
366 	ns->mtiming = ns->regs->timing;
367 	atcspi200_spi_get_clk(bus);
368 
369 	return 0;
370 }
371 
372 static int atcspi200_ofdata_to_platadata(struct udevice *bus)
373 {
374 	struct nds_spi_slave *ns = dev_get_priv(bus);
375 	const void *blob = gd->fdt_blob;
376 	int node = dev_of_offset(bus);
377 
378 	ns->regs = map_physmem(devfdt_get_addr(bus),
379 				 sizeof(struct atcspi200_spi_regs),
380 				 MAP_NOCACHE);
381 	if (!ns->regs) {
382 		printf("%s: could not map device address\n", __func__);
383 		return -EINVAL;
384 	}
385 	ns->num_cs = fdtdec_get_int(blob, node, "num-cs", 4);
386 
387 	return 0;
388 }
389 
390 static const struct dm_spi_ops atcspi200_spi_ops = {
391 	.claim_bus	= atcspi200_spi_claim_bus,
392 	.release_bus	= atcspi200_spi_release_bus,
393 	.xfer		= atcspi200_spi_xfer,
394 	.set_speed	= atcspi200_spi_set_speed,
395 	.set_mode	= atcspi200_spi_set_mode,
396 };
397 
398 static const struct udevice_id atcspi200_spi_ids[] = {
399 	{ .compatible = "andestech,atcspi200" },
400 	{ }
401 };
402 
403 U_BOOT_DRIVER(atcspi200_spi) = {
404 	.name = "atcspi200_spi",
405 	.id = UCLASS_SPI,
406 	.of_match = atcspi200_spi_ids,
407 	.ops = &atcspi200_spi_ops,
408 	.ofdata_to_platdata = atcspi200_ofdata_to_platadata,
409 	.priv_auto_alloc_size = sizeof(struct nds_spi_slave),
410 	.probe = atcspi200_spi_probe,
411 };
412