xref: /openbmc/u-boot/drivers/spi/atcspi200_spi.c (revision c0fb2fc0)
1 /*
2  * Andestech ATCSPI200 SPI controller driver.
3  *
4  * Copyright 2017 Andes Technology, Inc.
5  * Author: Rick Chen (rick@andestech.com)
6  *
7  * SPDX-License-Identifier:	GPL-2.0+
8  */
9 
10 #include <clk.h>
11 #include <common.h>
12 #include <malloc.h>
13 #include <spi.h>
14 #include <asm/io.h>
15 #include <dm.h>
16 
17 DECLARE_GLOBAL_DATA_PTR;
18 
19 #define MAX_TRANSFER_LEN	512
20 #define CHUNK_SIZE		1
21 #define SPI_TIMEOUT		0x100000
22 #define SPI0_BUS		0
23 #define SPI1_BUS		1
24 #define SPI0_BASE		0xf0b00000
25 #define SPI1_BASE		0xf0f00000
26 #define NSPI_MAX_CS_NUM		1
27 
28 struct atcspi200_spi_regs {
29 	u32	rev;
30 	u32	reserve1[3];
31 	u32	format;		/* 0x10 */
32 #define DATA_LENGTH(x)	((x-1)<<8)
33 	u32	pio;
34 	u32	reserve2[2];
35 	u32	tctrl;		/* 0x20 */
36 #define TRAMODE_OFFSET	24
37 #define TRAMODE_MASK	(0x0F<<TRAMODE_OFFSET)
38 #define TRAMODE_WR_SYNC	(0<<TRAMODE_OFFSET)
39 #define TRAMODE_WO	(1<<TRAMODE_OFFSET)
40 #define TRAMODE_RO	(2<<TRAMODE_OFFSET)
41 #define TRAMODE_WR	(3<<TRAMODE_OFFSET)
42 #define TRAMODE_RW	(4<<TRAMODE_OFFSET)
43 #define TRAMODE_WDR	(5<<TRAMODE_OFFSET)
44 #define TRAMODE_RDW	(6<<TRAMODE_OFFSET)
45 #define TRAMODE_NONE	(7<<TRAMODE_OFFSET)
46 #define TRAMODE_DW	(8<<TRAMODE_OFFSET)
47 #define TRAMODE_DR	(9<<TRAMODE_OFFSET)
48 #define WCNT_OFFSET	12
49 #define WCNT_MASK	(0x1FF<<WCNT_OFFSET)
50 #define RCNT_OFFSET	0
51 #define RCNT_MASK	(0x1FF<<RCNT_OFFSET)
52 	u32	cmd;
53 	u32	addr;
54 	u32	data;
55 	u32	ctrl;		/* 0x30 */
56 #define TXFTH_OFFSET	16
57 #define RXFTH_OFFSET	8
58 #define TXDMAEN		(1<<4)
59 #define RXDMAEN		(1<<3)
60 #define TXFRST		(1<<2)
61 #define RXFRST		(1<<1)
62 #define SPIRST		(1<<0)
63 	u32	status;
64 #define TXFFL		(1<<23)
65 #define TXEPTY		(1<<22)
66 #define TXFVE_MASK	(0x1F<<16)
67 #define RXFEM		(1<<14)
68 #define RXFVE_OFFSET	(8)
69 #define RXFVE_MASK	(0x1F<<RXFVE_OFFSET)
70 #define SPIBSY		(1<<0)
71 	u32	inten;
72 	u32	intsta;
73 	u32	timing;		/* 0x40 */
74 #define SCLK_DIV_MASK	0xFF
75 };
76 
77 struct nds_spi_slave {
78 	volatile struct atcspi200_spi_regs *regs;
79 	int		to;
80 	unsigned int	freq;
81 	ulong		clock;
82 	unsigned int	mode;
83 	u8 		num_cs;
84 	unsigned int	mtiming;
85 	size_t		cmd_len;
86 	u8		cmd_buf[16];
87 	size_t		data_len;
88 	size_t		tran_len;
89 	u8		*din;
90 	u8		*dout;
91 	unsigned int    max_transfer_length;
92 };
93 
94 static int __atcspi200_spi_set_speed(struct nds_spi_slave *ns)
95 {
96 	u32 tm;
97 	u8 div;
98 	tm = ns->regs->timing;
99 	tm &= ~SCLK_DIV_MASK;
100 
101 	if(ns->freq >= ns->clock)
102 		div =0xff;
103 	else{
104 		for (div = 0; div < 0xff; div++) {
105 			if (ns->freq >= ns->clock / (2 * (div + 1)))
106 				break;
107 		}
108 	}
109 
110 	tm |= div;
111 	ns->regs->timing = tm;
112 
113 	return 0;
114 
115 }
116 
117 static int __atcspi200_spi_claim_bus(struct nds_spi_slave *ns)
118 {
119 		unsigned int format=0;
120 		ns->regs->ctrl |= (TXFRST|RXFRST|SPIRST);
121 		while((ns->regs->ctrl &(TXFRST|RXFRST|SPIRST))&&(ns->to--))
122 			if(!ns->to)
123 				return -EINVAL;
124 
125 		ns->cmd_len = 0;
126 		format = ns->mode|DATA_LENGTH(8);
127 		ns->regs->format = format;
128 		__atcspi200_spi_set_speed(ns);
129 
130 		return 0;
131 }
132 
133 static int __atcspi200_spi_release_bus(struct nds_spi_slave *ns)
134 {
135 	/* do nothing */
136 	return 0;
137 }
138 
139 static int __atcspi200_spi_start(struct nds_spi_slave *ns)
140 {
141 	int i,olen=0;
142 	int tc = ns->regs->tctrl;
143 
144 	tc &= ~(WCNT_MASK|RCNT_MASK|TRAMODE_MASK);
145 	if ((ns->din)&&(ns->cmd_len))
146 		tc |= TRAMODE_WR;
147 	else if (ns->din)
148 		tc |= TRAMODE_RO;
149 	else
150 		tc |= TRAMODE_WO;
151 
152 	if(ns->dout)
153 		olen = ns->tran_len;
154 	tc |= (ns->cmd_len+olen-1) << WCNT_OFFSET;
155 
156 	if(ns->din)
157 		tc |= (ns->tran_len-1) << RCNT_OFFSET;
158 
159 	ns->regs->tctrl = tc;
160 	ns->regs->cmd = 1;
161 
162 	for (i=0;i<ns->cmd_len;i++)
163 		ns->regs->data = ns->cmd_buf[i];
164 
165 	return 0;
166 }
167 
168 static int __atcspi200_spi_stop(struct nds_spi_slave *ns)
169 {
170 	ns->regs->timing = ns->mtiming;
171 	while ((ns->regs->status & SPIBSY)&&(ns->to--))
172 		if (!ns->to)
173 			return -EINVAL;
174 
175 	return 0;
176 }
177 
178 static void __nspi_espi_tx(struct nds_spi_slave *ns, const void *dout)
179 {
180 	ns->regs->data = *(u8 *)dout;
181 }
182 
183 static int __nspi_espi_rx(struct nds_spi_slave *ns, void *din, unsigned int bytes)
184 {
185 	*(u8 *)din = ns->regs->data;
186 	return bytes;
187 }
188 
189 
190 static int __atcspi200_spi_xfer(struct nds_spi_slave *ns,
191 		unsigned int bitlen,  const void *data_out, void *data_in,
192 		unsigned long flags)
193 {
194 		unsigned int event, rx_bytes;
195 		const void *dout = NULL;
196 		void *din = NULL;
197 		int num_blks, num_chunks, max_tran_len, tran_len;
198 		int num_bytes;
199 		u8 *cmd_buf = ns->cmd_buf;
200 		size_t cmd_len = ns->cmd_len;
201 		size_t data_len = bitlen / 8;
202 		int rf_cnt;
203 		int ret = 0;
204 
205 		max_tran_len = ns->max_transfer_length;
206 		switch (flags) {
207 		case SPI_XFER_BEGIN:
208 			cmd_len = ns->cmd_len = data_len;
209 			memcpy(cmd_buf, data_out, cmd_len);
210 			return 0;
211 
212 		case 0:
213 		case SPI_XFER_END:
214 			if (bitlen == 0) {
215 				return 0;
216 			}
217 			ns->data_len = data_len;
218 			ns->din = (u8 *)data_in;
219 			ns->dout = (u8 *)data_out;
220 			break;
221 
222 		case SPI_XFER_BEGIN | SPI_XFER_END:
223 			ns->data_len = 0;
224 			ns->din = 0;
225 			ns->dout = 0;
226 			cmd_len = ns->cmd_len = data_len;
227 			memcpy(cmd_buf, data_out, cmd_len);
228 			data_out = 0;
229 			data_len = 0;
230 			__atcspi200_spi_start(ns);
231 			break;
232 		}
233 		debug("spi_xfer: data_out %08X(%p) data_in %08X(%p) data_len %u\n",
234 		      *(uint *)data_out, data_out, *(uint *)data_in, data_in, data_len);
235 		num_chunks = DIV_ROUND_UP(data_len, max_tran_len);
236 		din = data_in;
237 		dout = data_out;
238 		while (num_chunks--) {
239 			tran_len = min(data_len, (size_t)max_tran_len);
240 			ns->tran_len = tran_len;
241 			num_blks = DIV_ROUND_UP(tran_len , CHUNK_SIZE);
242 			num_bytes = (tran_len) % CHUNK_SIZE;
243 			if(num_bytes == 0)
244 				num_bytes = CHUNK_SIZE;
245 			__atcspi200_spi_start(ns);
246 
247 			while (num_blks) {
248 				event = in_le32(&ns->regs->status);
249 				if ((event & TXEPTY) && (data_out)) {
250 					__nspi_espi_tx(ns, dout);
251 					num_blks -= CHUNK_SIZE;
252 					dout += CHUNK_SIZE;
253 				}
254 
255 				if ((event & RXFVE_MASK) && (data_in)) {
256 					rf_cnt = ((event & RXFVE_MASK)>> RXFVE_OFFSET);
257 					if (rf_cnt >= CHUNK_SIZE)
258 						rx_bytes = CHUNK_SIZE;
259 					else if (num_blks == 1 && rf_cnt == num_bytes)
260 						rx_bytes = num_bytes;
261 					else
262 						continue;
263 
264 					if (__nspi_espi_rx(ns, din, rx_bytes) == rx_bytes) {
265 						num_blks -= CHUNK_SIZE;
266 						din = (unsigned char *)din + rx_bytes;
267 					}
268 				}
269 			}
270 
271 			data_len -= tran_len;
272 			if(data_len)
273 			{
274 				ns->cmd_buf[1] += ((tran_len>>16)&0xff);
275 				ns->cmd_buf[2] += ((tran_len>>8)&0xff);
276 				ns->cmd_buf[3] += ((tran_len)&0xff);
277 				ns->data_len = data_len;
278 			}
279 			ret = __atcspi200_spi_stop(ns);
280 		}
281 		ret = __atcspi200_spi_stop(ns);
282 
283 		return ret;
284 }
285 
286 static int atcspi200_spi_set_speed(struct udevice *bus, uint max_hz)
287 {
288 	struct nds_spi_slave *ns = dev_get_priv(bus);
289 
290 	debug("%s speed %u\n", __func__, max_hz);
291 
292 	ns->freq = max_hz;
293 	__atcspi200_spi_set_speed(ns);
294 
295 	return 0;
296 }
297 
298 static int atcspi200_spi_set_mode(struct udevice *bus, uint mode)
299 {
300 	struct nds_spi_slave *ns = dev_get_priv(bus);
301 
302 	debug("%s mode %u\n", __func__, mode);
303 	ns->mode = mode;
304 
305 	return 0;
306 }
307 
308 static int atcspi200_spi_claim_bus(struct udevice *dev)
309 {
310 	struct dm_spi_slave_platdata *slave_plat =
311 		dev_get_parent_platdata(dev);
312 	struct udevice *bus = dev->parent;
313 	struct nds_spi_slave *ns = dev_get_priv(bus);
314 
315 	if (slave_plat->cs >= ns->num_cs) {
316 		printf("Invalid SPI chipselect\n");
317 		return -EINVAL;
318 	}
319 
320 	return __atcspi200_spi_claim_bus(ns);
321 }
322 
323 static int atcspi200_spi_release_bus(struct udevice *dev)
324 {
325 	struct nds_spi_slave *ns = dev_get_priv(dev->parent);
326 
327 	return __atcspi200_spi_release_bus(ns);
328 }
329 
330 static int atcspi200_spi_xfer(struct udevice *dev, unsigned int bitlen,
331 			    const void *dout, void *din,
332 			    unsigned long flags)
333 {
334 	struct udevice *bus = dev->parent;
335 	struct nds_spi_slave *ns = dev_get_priv(bus);
336 
337 	return __atcspi200_spi_xfer(ns, bitlen, dout, din, flags);
338 }
339 
340 static int atcspi200_spi_get_clk(struct udevice *bus)
341 {
342 	struct nds_spi_slave *ns = dev_get_priv(bus);
343 	struct clk clk;
344 	ulong clk_rate;
345 	int ret;
346 
347 	ret = clk_get_by_index(bus, 0, &clk);
348 	if (ret)
349 		return -EINVAL;
350 
351 	clk_rate = clk_get_rate(&clk);
352 	if (!clk_rate)
353 		return -EINVAL;
354 
355 	ns->clock = clk_rate;
356 	clk_free(&clk);
357 
358 	return 0;
359 }
360 
361 static int atcspi200_spi_probe(struct udevice *bus)
362 {
363 	struct nds_spi_slave *ns = dev_get_priv(bus);
364 
365 	ns->to = SPI_TIMEOUT;
366 	ns->max_transfer_length = MAX_TRANSFER_LEN;
367 	ns->mtiming = ns->regs->timing;
368 	atcspi200_spi_get_clk(bus);
369 
370 	return 0;
371 }
372 
373 static int atcspi200_ofdata_to_platadata(struct udevice *bus)
374 {
375 	struct nds_spi_slave *ns = dev_get_priv(bus);
376 	const void *blob = gd->fdt_blob;
377 	int node = dev_of_offset(bus);
378 
379 	ns->regs = map_physmem(devfdt_get_addr(bus),
380 				 sizeof(struct atcspi200_spi_regs),
381 				 MAP_NOCACHE);
382 	if (!ns->regs) {
383 		printf("%s: could not map device address\n", __func__);
384 		return -EINVAL;
385 	}
386 	ns->num_cs = fdtdec_get_int(blob, node, "num-cs", 4);
387 
388 	return 0;
389 }
390 
391 static const struct dm_spi_ops atcspi200_spi_ops = {
392 	.claim_bus	= atcspi200_spi_claim_bus,
393 	.release_bus	= atcspi200_spi_release_bus,
394 	.xfer		= atcspi200_spi_xfer,
395 	.set_speed	= atcspi200_spi_set_speed,
396 	.set_mode	= atcspi200_spi_set_mode,
397 };
398 
399 static const struct udevice_id atcspi200_spi_ids[] = {
400 	{ .compatible = "andestech,atcspi200" },
401 	{ }
402 };
403 
404 U_BOOT_DRIVER(atcspi200_spi) = {
405 	.name = "atcspi200_spi",
406 	.id = UCLASS_SPI,
407 	.of_match = atcspi200_spi_ids,
408 	.ops = &atcspi200_spi_ops,
409 	.ofdata_to_platdata = atcspi200_ofdata_to_platadata,
410 	.priv_auto_alloc_size = sizeof(struct nds_spi_slave),
411 	.probe = atcspi200_spi_probe,
412 };
413