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 <common.h>
10 #include <clk.h>
11 #include <log.h>
12 #include <malloc.h>
13 #include <spi.h>
14 #include <asm/global_data.h>
15 #include <asm/io.h>
16 #include <dm.h>
17 
18 DECLARE_GLOBAL_DATA_PTR;
19 
20 #define MAX_TRANSFER_LEN	512
21 #define CHUNK_SIZE		1
22 #define SPI_TIMEOUT		0x100000
23 #define SPI0_BUS		0
24 #define SPI1_BUS		1
25 #define SPI0_BASE		0xf0b00000
26 #define SPI1_BASE		0xf0f00000
27 #define NSPI_MAX_CS_NUM		1
28 
29 struct atcspi200_spi_regs {
30 	u32	rev;
31 	u32	reserve1[3];
32 	u32	format;		/* 0x10 */
33 #define DATA_LENGTH(x)	((x-1)<<8)
34 	u32	pio;
35 	u32	reserve2[2];
36 	u32	tctrl;		/* 0x20 */
37 #define TRAMODE_OFFSET	24
38 #define TRAMODE_MASK	(0x0F<<TRAMODE_OFFSET)
39 #define TRAMODE_WR_SYNC	(0<<TRAMODE_OFFSET)
40 #define TRAMODE_WO	(1<<TRAMODE_OFFSET)
41 #define TRAMODE_RO	(2<<TRAMODE_OFFSET)
42 #define TRAMODE_WR	(3<<TRAMODE_OFFSET)
43 #define TRAMODE_RW	(4<<TRAMODE_OFFSET)
44 #define TRAMODE_WDR	(5<<TRAMODE_OFFSET)
45 #define TRAMODE_RDW	(6<<TRAMODE_OFFSET)
46 #define TRAMODE_NONE	(7<<TRAMODE_OFFSET)
47 #define TRAMODE_DW	(8<<TRAMODE_OFFSET)
48 #define TRAMODE_DR	(9<<TRAMODE_OFFSET)
49 #define WCNT_OFFSET	12
50 #define WCNT_MASK	(0x1FF<<WCNT_OFFSET)
51 #define RCNT_OFFSET	0
52 #define RCNT_MASK	(0x1FF<<RCNT_OFFSET)
53 	u32	cmd;
54 	u32	addr;
55 	u32	data;
56 	u32	ctrl;		/* 0x30 */
57 #define TXFTH_OFFSET	16
58 #define RXFTH_OFFSET	8
59 #define TXDMAEN		(1<<4)
60 #define RXDMAEN		(1<<3)
61 #define TXFRST		(1<<2)
62 #define RXFRST		(1<<1)
63 #define SPIRST		(1<<0)
64 	u32	status;
65 #define TXFFL		(1<<23)
66 #define TXEPTY		(1<<22)
67 #define TXFVE_MASK	(0x1F<<16)
68 #define RXFEM		(1<<14)
69 #define RXFVE_OFFSET	(8)
70 #define RXFVE_MASK	(0x1F<<RXFVE_OFFSET)
71 #define SPIBSY		(1<<0)
72 	u32	inten;
73 	u32	intsta;
74 	u32	timing;		/* 0x40 */
75 #define SCLK_DIV_MASK	0xFF
76 };
77 
78 struct nds_spi_slave {
79 	volatile struct atcspi200_spi_regs *regs;
80 	int		to;
81 	unsigned int	freq;
82 	ulong		clock;
83 	unsigned int	mode;
84 	u8 		num_cs;
85 	unsigned int	mtiming;
86 	size_t		cmd_len;
87 	u8		cmd_buf[16];
88 	size_t		data_len;
89 	size_t		tran_len;
90 	u8		*din;
91 	u8		*dout;
92 	unsigned int    max_transfer_length;
93 };
94 
__atcspi200_spi_set_speed(struct nds_spi_slave * ns)95 static int __atcspi200_spi_set_speed(struct nds_spi_slave *ns)
96 {
97 	u32 tm;
98 	u8 div;
99 	tm = ns->regs->timing;
100 	tm &= ~SCLK_DIV_MASK;
101 
102 	if(ns->freq >= ns->clock)
103 		div =0xff;
104 	else{
105 		for (div = 0; div < 0xff; div++) {
106 			if (ns->freq >= ns->clock / (2 * (div + 1)))
107 				break;
108 		}
109 	}
110 
111 	tm |= div;
112 	ns->regs->timing = tm;
113 
114 	return 0;
115 
116 }
117 
__atcspi200_spi_claim_bus(struct nds_spi_slave * ns)118 static int __atcspi200_spi_claim_bus(struct nds_spi_slave *ns)
119 {
120 		unsigned int format=0;
121 		ns->regs->ctrl |= (TXFRST|RXFRST|SPIRST);
122 		while((ns->regs->ctrl &(TXFRST|RXFRST|SPIRST))&&(ns->to--))
123 			if(!ns->to)
124 				return -EINVAL;
125 
126 		ns->cmd_len = 0;
127 		format = ns->mode|DATA_LENGTH(8);
128 		ns->regs->format = format;
129 		__atcspi200_spi_set_speed(ns);
130 
131 		return 0;
132 }
133 
__atcspi200_spi_release_bus(struct nds_spi_slave * ns)134 static int __atcspi200_spi_release_bus(struct nds_spi_slave *ns)
135 {
136 	/* do nothing */
137 	return 0;
138 }
139 
__atcspi200_spi_start(struct nds_spi_slave * ns)140 static int __atcspi200_spi_start(struct nds_spi_slave *ns)
141 {
142 	int i,olen=0;
143 	int tc = ns->regs->tctrl;
144 
145 	tc &= ~(WCNT_MASK|RCNT_MASK|TRAMODE_MASK);
146 	if ((ns->din)&&(ns->cmd_len))
147 		tc |= TRAMODE_WR;
148 	else if (ns->din)
149 		tc |= TRAMODE_RO;
150 	else
151 		tc |= TRAMODE_WO;
152 
153 	if(ns->dout)
154 		olen = ns->tran_len;
155 	tc |= (ns->cmd_len+olen-1) << WCNT_OFFSET;
156 
157 	if(ns->din)
158 		tc |= (ns->tran_len-1) << RCNT_OFFSET;
159 
160 	ns->regs->tctrl = tc;
161 	ns->regs->cmd = 1;
162 
163 	for (i=0;i<ns->cmd_len;i++)
164 		ns->regs->data = ns->cmd_buf[i];
165 
166 	return 0;
167 }
168 
__atcspi200_spi_stop(struct nds_spi_slave * ns)169 static int __atcspi200_spi_stop(struct nds_spi_slave *ns)
170 {
171 	ns->regs->timing = ns->mtiming;
172 	while ((ns->regs->status & SPIBSY)&&(ns->to--))
173 		if (!ns->to)
174 			return -EINVAL;
175 
176 	return 0;
177 }
178 
__nspi_espi_tx(struct nds_spi_slave * ns,const void * dout)179 static void __nspi_espi_tx(struct nds_spi_slave *ns, const void *dout)
180 {
181 	ns->regs->data = *(u8 *)dout;
182 }
183 
__nspi_espi_rx(struct nds_spi_slave * ns,void * din,unsigned int bytes)184 static int __nspi_espi_rx(struct nds_spi_slave *ns, void *din, unsigned int bytes)
185 {
186 	*(u8 *)din = ns->regs->data;
187 	return bytes;
188 }
189 
190 
__atcspi200_spi_xfer(struct nds_spi_slave * ns,unsigned int bitlen,const void * data_out,void * data_in,unsigned long flags)191 static int __atcspi200_spi_xfer(struct nds_spi_slave *ns,
192 		unsigned int bitlen,  const void *data_out, void *data_in,
193 		unsigned long flags)
194 {
195 		unsigned int event, rx_bytes;
196 		const void *dout = NULL;
197 		void *din = NULL;
198 		int num_blks, num_chunks, max_tran_len, tran_len;
199 		int num_bytes;
200 		u8 *cmd_buf = ns->cmd_buf;
201 		size_t cmd_len = ns->cmd_len;
202 		unsigned long data_len = bitlen / 8;
203 		int rf_cnt;
204 		int ret = 0, timeout = 0;
205 
206 		max_tran_len = ns->max_transfer_length;
207 		switch (flags) {
208 		case SPI_XFER_BEGIN:
209 			cmd_len = ns->cmd_len = data_len;
210 			memcpy(cmd_buf, data_out, cmd_len);
211 			return 0;
212 
213 		case 0:
214 		case SPI_XFER_END:
215 			if (bitlen == 0) {
216 				return 0;
217 			}
218 			ns->data_len = data_len;
219 			ns->din = (u8 *)data_in;
220 			ns->dout = (u8 *)data_out;
221 			break;
222 
223 		case SPI_XFER_BEGIN | SPI_XFER_END:
224 			ns->data_len = 0;
225 			ns->din = 0;
226 			ns->dout = 0;
227 			cmd_len = ns->cmd_len = data_len;
228 			memcpy(cmd_buf, data_out, cmd_len);
229 			data_out = 0;
230 			data_len = 0;
231 			__atcspi200_spi_start(ns);
232 			break;
233 		}
234 		if (data_out)
235 			debug("spi_xfer: data_out %08X(%p) data_in %08X(%p) data_len %lu\n",
236 			      *(uint *)data_out, data_out, *(uint *)data_in,
237 			      data_in, data_len);
238 		num_chunks = DIV_ROUND_UP(data_len, max_tran_len);
239 		din = data_in;
240 		dout = data_out;
241 		while (num_chunks--) {
242 			tran_len = min((size_t)data_len, (size_t)max_tran_len);
243 			ns->tran_len = tran_len;
244 			num_blks = DIV_ROUND_UP(tran_len , CHUNK_SIZE);
245 			num_bytes = (tran_len) % CHUNK_SIZE;
246 			timeout = SPI_TIMEOUT;
247 			if(num_bytes == 0)
248 				num_bytes = CHUNK_SIZE;
249 			__atcspi200_spi_start(ns);
250 
251 			while (num_blks && (timeout--)) {
252 				event = in_le32(&ns->regs->status);
253 				if ((event & TXEPTY) && (data_out)) {
254 					__nspi_espi_tx(ns, dout);
255 					num_blks -= CHUNK_SIZE;
256 					dout += CHUNK_SIZE;
257 				}
258 
259 				if ((event & RXFVE_MASK) && (data_in)) {
260 					rf_cnt = ((event & RXFVE_MASK)>> RXFVE_OFFSET);
261 					if (rf_cnt >= CHUNK_SIZE)
262 						rx_bytes = CHUNK_SIZE;
263 					else if (num_blks == 1 && rf_cnt == num_bytes)
264 						rx_bytes = num_bytes;
265 					else
266 						continue;
267 
268 					if (__nspi_espi_rx(ns, din, rx_bytes) == rx_bytes) {
269 						num_blks -= CHUNK_SIZE;
270 						din = (unsigned char *)din + rx_bytes;
271 					}
272 				}
273 
274 				if (!timeout) {
275 					debug("spi_xfer: %s() timeout\n", __func__);
276 					break;
277 				}
278 			}
279 
280 			data_len -= tran_len;
281 			if(data_len)
282 			{
283 				ns->cmd_buf[1] += ((tran_len>>16)&0xff);
284 				ns->cmd_buf[2] += ((tran_len>>8)&0xff);
285 				ns->cmd_buf[3] += ((tran_len)&0xff);
286 				ns->data_len = data_len;
287 			}
288 			ret = __atcspi200_spi_stop(ns);
289 		}
290 		ret = __atcspi200_spi_stop(ns);
291 
292 		return ret;
293 }
294 
atcspi200_spi_set_speed(struct udevice * bus,uint max_hz)295 static int atcspi200_spi_set_speed(struct udevice *bus, uint max_hz)
296 {
297 	struct nds_spi_slave *ns = dev_get_priv(bus);
298 
299 	debug("%s speed %u\n", __func__, max_hz);
300 
301 	ns->freq = max_hz;
302 	__atcspi200_spi_set_speed(ns);
303 
304 	return 0;
305 }
306 
atcspi200_spi_set_mode(struct udevice * bus,uint mode)307 static int atcspi200_spi_set_mode(struct udevice *bus, uint mode)
308 {
309 	struct nds_spi_slave *ns = dev_get_priv(bus);
310 
311 	debug("%s mode %u\n", __func__, mode);
312 	ns->mode = mode;
313 
314 	return 0;
315 }
316 
atcspi200_spi_claim_bus(struct udevice * dev)317 static int atcspi200_spi_claim_bus(struct udevice *dev)
318 {
319 	struct dm_spi_slave_plat *slave_plat =
320 		dev_get_parent_plat(dev);
321 	struct udevice *bus = dev->parent;
322 	struct nds_spi_slave *ns = dev_get_priv(bus);
323 
324 	if (slave_plat->cs >= ns->num_cs) {
325 		printf("Invalid SPI chipselect\n");
326 		return -EINVAL;
327 	}
328 
329 	return __atcspi200_spi_claim_bus(ns);
330 }
331 
atcspi200_spi_release_bus(struct udevice * dev)332 static int atcspi200_spi_release_bus(struct udevice *dev)
333 {
334 	struct nds_spi_slave *ns = dev_get_priv(dev->parent);
335 
336 	return __atcspi200_spi_release_bus(ns);
337 }
338 
atcspi200_spi_xfer(struct udevice * dev,unsigned int bitlen,const void * dout,void * din,unsigned long flags)339 static int atcspi200_spi_xfer(struct udevice *dev, unsigned int bitlen,
340 			    const void *dout, void *din,
341 			    unsigned long flags)
342 {
343 	struct udevice *bus = dev->parent;
344 	struct nds_spi_slave *ns = dev_get_priv(bus);
345 
346 	return __atcspi200_spi_xfer(ns, bitlen, dout, din, flags);
347 }
348 
atcspi200_spi_get_clk(struct udevice * bus)349 static int atcspi200_spi_get_clk(struct udevice *bus)
350 {
351 	struct nds_spi_slave *ns = dev_get_priv(bus);
352 	struct clk clk;
353 	ulong clk_rate;
354 	int ret;
355 
356 	ret = clk_get_by_index(bus, 0, &clk);
357 	if (ret)
358 		return -EINVAL;
359 
360 	clk_rate = clk_get_rate(&clk);
361 	if (!clk_rate)
362 		return -EINVAL;
363 
364 	ns->clock = clk_rate;
365 	clk_free(&clk);
366 
367 	return 0;
368 }
369 
atcspi200_spi_probe(struct udevice * bus)370 static int atcspi200_spi_probe(struct udevice *bus)
371 {
372 	struct nds_spi_slave *ns = dev_get_priv(bus);
373 
374 	ns->to = SPI_TIMEOUT;
375 	ns->max_transfer_length = MAX_TRANSFER_LEN;
376 	ns->mtiming = ns->regs->timing;
377 	atcspi200_spi_get_clk(bus);
378 
379 	return 0;
380 }
381 
atcspi200_ofdata_to_platadata(struct udevice * bus)382 static int atcspi200_ofdata_to_platadata(struct udevice *bus)
383 {
384 	struct nds_spi_slave *ns = dev_get_priv(bus);
385 	const void *blob = gd->fdt_blob;
386 	int node = dev_of_offset(bus);
387 
388 	ns->regs = map_physmem(dev_read_addr(bus),
389 				 sizeof(struct atcspi200_spi_regs),
390 				 MAP_NOCACHE);
391 	if (!ns->regs) {
392 		printf("%s: could not map device address\n", __func__);
393 		return -EINVAL;
394 	}
395 	ns->num_cs = fdtdec_get_int(blob, node, "num-cs", 4);
396 
397 	return 0;
398 }
399 
400 static const struct dm_spi_ops atcspi200_spi_ops = {
401 	.claim_bus	= atcspi200_spi_claim_bus,
402 	.release_bus	= atcspi200_spi_release_bus,
403 	.xfer		= atcspi200_spi_xfer,
404 	.set_speed	= atcspi200_spi_set_speed,
405 	.set_mode	= atcspi200_spi_set_mode,
406 };
407 
408 static const struct udevice_id atcspi200_spi_ids[] = {
409 	{ .compatible = "andestech,atcspi200" },
410 	{ }
411 };
412 
413 U_BOOT_DRIVER(atcspi200_spi) = {
414 	.name = "atcspi200_spi",
415 	.id = UCLASS_SPI,
416 	.of_match = atcspi200_spi_ids,
417 	.ops = &atcspi200_spi_ops,
418 	.of_to_plat = atcspi200_ofdata_to_platadata,
419 	.priv_auto	= sizeof(struct nds_spi_slave),
420 	.probe = atcspi200_spi_probe,
421 };
422