1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * spi driver for rockchip
4 *
5 * (C) 2019 Theobroma Systems Design und Consulting GmbH
6 *
7 * (C) Copyright 2015 Google, Inc
8 *
9 * (C) Copyright 2008-2013 Rockchip Electronics
10 * Peter, Software Engineering, <superpeter.cai@gmail.com>.
11 */
12
13 #include <common.h>
14 #include <clk.h>
15 #include <dm.h>
16 #include <dt-structs.h>
17 #include <errno.h>
18 #include <spi.h>
19 #include <time.h>
20 #include <linux/errno.h>
21 #include <asm/io.h>
22 #include <asm/arch-rockchip/clock.h>
23 #include <asm/arch-rockchip/periph.h>
24 #include <dm/pinctrl.h>
25 #include "rk_spi.h"
26
27 /* Change to 1 to output registers at the start of each transaction */
28 #define DEBUG_RK_SPI 0
29
30 /*
31 * ctrlr1 is 16-bits, so we should support lengths of 0xffff + 1. However,
32 * the controller seems to hang when given 0x10000, so stick with this for now.
33 */
34 #define ROCKCHIP_SPI_MAX_TRANLEN 0xffff
35
36 struct rockchip_spi_params {
37 /* RXFIFO overruns and TXFIFO underruns stop the master clock */
38 bool master_manages_fifo;
39 };
40
41 struct rockchip_spi_platdata {
42 #if CONFIG_IS_ENABLED(OF_PLATDATA)
43 struct dtd_rockchip_rk3288_spi of_plat;
44 #endif
45 s32 frequency; /* Default clock frequency, -1 for none */
46 fdt_addr_t base;
47 uint deactivate_delay_us; /* Delay to wait after deactivate */
48 uint activate_delay_us; /* Delay to wait after activate */
49 };
50
51 struct rockchip_spi_priv {
52 struct rockchip_spi *regs;
53 struct clk clk;
54 unsigned int max_freq;
55 unsigned int mode;
56 ulong last_transaction_us; /* Time of last transaction end */
57 unsigned int speed_hz;
58 unsigned int last_speed_hz;
59 uint input_rate;
60 };
61
62 #define SPI_FIFO_DEPTH 32
63
rkspi_dump_regs(struct rockchip_spi * regs)64 static void rkspi_dump_regs(struct rockchip_spi *regs)
65 {
66 debug("ctrl0: \t\t0x%08x\n", readl(®s->ctrlr0));
67 debug("ctrl1: \t\t0x%08x\n", readl(®s->ctrlr1));
68 debug("ssienr: \t\t0x%08x\n", readl(®s->enr));
69 debug("ser: \t\t0x%08x\n", readl(®s->ser));
70 debug("baudr: \t\t0x%08x\n", readl(®s->baudr));
71 debug("txftlr: \t\t0x%08x\n", readl(®s->txftlr));
72 debug("rxftlr: \t\t0x%08x\n", readl(®s->rxftlr));
73 debug("txflr: \t\t0x%08x\n", readl(®s->txflr));
74 debug("rxflr: \t\t0x%08x\n", readl(®s->rxflr));
75 debug("sr: \t\t0x%08x\n", readl(®s->sr));
76 debug("imr: \t\t0x%08x\n", readl(®s->imr));
77 debug("isr: \t\t0x%08x\n", readl(®s->isr));
78 debug("dmacr: \t\t0x%08x\n", readl(®s->dmacr));
79 debug("dmatdlr: \t0x%08x\n", readl(®s->dmatdlr));
80 debug("dmardlr: \t0x%08x\n", readl(®s->dmardlr));
81 }
82
rkspi_enable_chip(struct rockchip_spi * regs,bool enable)83 static void rkspi_enable_chip(struct rockchip_spi *regs, bool enable)
84 {
85 writel(enable ? 1 : 0, ®s->enr);
86 }
87
rkspi_set_clk(struct rockchip_spi_priv * priv,uint speed)88 static void rkspi_set_clk(struct rockchip_spi_priv *priv, uint speed)
89 {
90 /*
91 * We should try not to exceed the speed requested by the caller:
92 * when selecting a divider, we need to make sure we round up.
93 */
94 uint clk_div = DIV_ROUND_UP(priv->input_rate, speed);
95
96 /* The baudrate register (BAUDR) is defined as a 32bit register where
97 * the upper 16bit are reserved and having 'Fsclk_out' in the lower
98 * 16bits with 'Fsclk_out' defined as follows:
99 *
100 * Fsclk_out = Fspi_clk/ SCKDV
101 * Where SCKDV is any even value between 2 and 65534.
102 */
103 if (clk_div > 0xfffe) {
104 clk_div = 0xfffe;
105 debug("%s: can't divide down to %d Hz (actual will be %d Hz)\n",
106 __func__, speed, priv->input_rate / clk_div);
107 }
108
109 /* Round up to the next even 16bit number */
110 clk_div = (clk_div + 1) & 0xfffe;
111
112 debug("spi speed %u, div %u\n", speed, clk_div);
113
114 clrsetbits_le32(&priv->regs->baudr, 0xffff, clk_div);
115 priv->last_speed_hz = speed;
116 }
117
rkspi_wait_till_not_busy(struct rockchip_spi * regs)118 static int rkspi_wait_till_not_busy(struct rockchip_spi *regs)
119 {
120 unsigned long start;
121
122 start = get_timer(0);
123 while (readl(®s->sr) & SR_BUSY) {
124 if (get_timer(start) > ROCKCHIP_SPI_TIMEOUT_MS) {
125 debug("RK SPI: Status keeps busy for 1000us after a read/write!\n");
126 return -ETIMEDOUT;
127 }
128 }
129
130 return 0;
131 }
132
spi_cs_activate(struct udevice * dev,uint cs)133 static void spi_cs_activate(struct udevice *dev, uint cs)
134 {
135 struct udevice *bus = dev->parent;
136 struct rockchip_spi_platdata *plat = bus->platdata;
137 struct rockchip_spi_priv *priv = dev_get_priv(bus);
138 struct rockchip_spi *regs = priv->regs;
139
140 /* If it's too soon to do another transaction, wait */
141 if (plat->deactivate_delay_us && priv->last_transaction_us) {
142 ulong delay_us; /* The delay completed so far */
143 delay_us = timer_get_us() - priv->last_transaction_us;
144 if (delay_us < plat->deactivate_delay_us) {
145 ulong additional_delay_us =
146 plat->deactivate_delay_us - delay_us;
147 debug("%s: delaying by %ld us\n",
148 __func__, additional_delay_us);
149 udelay(additional_delay_us);
150 }
151 }
152
153 debug("activate cs%u\n", cs);
154 writel(1 << cs, ®s->ser);
155 if (plat->activate_delay_us)
156 udelay(plat->activate_delay_us);
157 }
158
spi_cs_deactivate(struct udevice * dev,uint cs)159 static void spi_cs_deactivate(struct udevice *dev, uint cs)
160 {
161 struct udevice *bus = dev->parent;
162 struct rockchip_spi_platdata *plat = bus->platdata;
163 struct rockchip_spi_priv *priv = dev_get_priv(bus);
164 struct rockchip_spi *regs = priv->regs;
165
166 debug("deactivate cs%u\n", cs);
167 writel(0, ®s->ser);
168
169 /* Remember time of this transaction so we can honour the bus delay */
170 if (plat->deactivate_delay_us)
171 priv->last_transaction_us = timer_get_us();
172 }
173
174 #if CONFIG_IS_ENABLED(OF_PLATDATA)
conv_of_platdata(struct udevice * dev)175 static int conv_of_platdata(struct udevice *dev)
176 {
177 struct rockchip_spi_platdata *plat = dev->platdata;
178 struct dtd_rockchip_rk3288_spi *dtplat = &plat->of_plat;
179 struct rockchip_spi_priv *priv = dev_get_priv(dev);
180 int ret;
181
182 plat->base = dtplat->reg[0];
183 plat->frequency = 20000000;
184 ret = clk_get_by_index_platdata(dev, 0, dtplat->clocks, &priv->clk);
185 if (ret < 0)
186 return ret;
187 dev->req_seq = 0;
188
189 return 0;
190 }
191 #endif
192
rockchip_spi_ofdata_to_platdata(struct udevice * bus)193 static int rockchip_spi_ofdata_to_platdata(struct udevice *bus)
194 {
195 #if !CONFIG_IS_ENABLED(OF_PLATDATA)
196 struct rockchip_spi_platdata *plat = dev_get_platdata(bus);
197 struct rockchip_spi_priv *priv = dev_get_priv(bus);
198 int ret;
199
200 plat->base = dev_read_addr(bus);
201
202 ret = clk_get_by_index(bus, 0, &priv->clk);
203 if (ret < 0) {
204 debug("%s: Could not get clock for %s: %d\n", __func__,
205 bus->name, ret);
206 return ret;
207 }
208
209 plat->frequency =
210 dev_read_u32_default(bus, "spi-max-frequency", 50000000);
211 plat->deactivate_delay_us =
212 dev_read_u32_default(bus, "spi-deactivate-delay", 0);
213 plat->activate_delay_us =
214 dev_read_u32_default(bus, "spi-activate-delay", 0);
215
216 debug("%s: base=%x, max-frequency=%d, deactivate_delay=%d\n",
217 __func__, (uint)plat->base, plat->frequency,
218 plat->deactivate_delay_us);
219 #endif
220
221 return 0;
222 }
223
rockchip_spi_calc_modclk(ulong max_freq)224 static int rockchip_spi_calc_modclk(ulong max_freq)
225 {
226 /*
227 * While this is not strictly correct for the RK3368, as the
228 * GPLL will be 576MHz, things will still work, as the
229 * clk_set_rate(...) implementation in our clock-driver will
230 * chose the next closest rate not exceeding what we request
231 * based on the output of this function.
232 */
233
234 unsigned div;
235 const unsigned long gpll_hz = 594000000UL;
236
237 /*
238 * We need to find an input clock that provides at least twice
239 * the maximum frequency and can be generated from the assumed
240 * speed of GPLL (594MHz) using an integer divider.
241 *
242 * To give us more achievable bitrates at higher speeds (these
243 * are generated by dividing by an even 16-bit integer from
244 * this frequency), we try to have an input frequency of at
245 * least 4x our max_freq.
246 */
247
248 div = DIV_ROUND_UP(gpll_hz, max_freq * 4);
249 return gpll_hz / div;
250 }
251
rockchip_spi_probe(struct udevice * bus)252 static int rockchip_spi_probe(struct udevice *bus)
253 {
254 struct rockchip_spi_platdata *plat = dev_get_platdata(bus);
255 struct rockchip_spi_priv *priv = dev_get_priv(bus);
256 int ret;
257
258 debug("%s: probe\n", __func__);
259 #if CONFIG_IS_ENABLED(OF_PLATDATA)
260 ret = conv_of_platdata(bus);
261 if (ret)
262 return ret;
263 #endif
264 priv->regs = (struct rockchip_spi *)plat->base;
265
266 priv->last_transaction_us = timer_get_us();
267 priv->max_freq = plat->frequency;
268
269 /* Clamp the value from the DTS against any hardware limits */
270 if (priv->max_freq > ROCKCHIP_SPI_MAX_RATE)
271 priv->max_freq = ROCKCHIP_SPI_MAX_RATE;
272
273 /* Find a module-input clock that fits with the max_freq setting */
274 ret = clk_set_rate(&priv->clk,
275 rockchip_spi_calc_modclk(priv->max_freq));
276 if (ret < 0) {
277 debug("%s: Failed to set clock: %d\n", __func__, ret);
278 return ret;
279 }
280 priv->input_rate = ret;
281 debug("%s: rate = %u\n", __func__, priv->input_rate);
282
283 return 0;
284 }
285
rockchip_spi_claim_bus(struct udevice * dev)286 static int rockchip_spi_claim_bus(struct udevice *dev)
287 {
288 struct udevice *bus = dev->parent;
289 struct rockchip_spi_priv *priv = dev_get_priv(bus);
290 struct rockchip_spi *regs = priv->regs;
291 uint ctrlr0;
292
293 /* Disable the SPI hardware */
294 rkspi_enable_chip(regs, false);
295
296 if (priv->speed_hz != priv->last_speed_hz)
297 rkspi_set_clk(priv, priv->speed_hz);
298
299 /* Operation Mode */
300 ctrlr0 = OMOD_MASTER << OMOD_SHIFT;
301
302 /* Data Frame Size */
303 ctrlr0 |= DFS_8BIT << DFS_SHIFT;
304
305 /* set SPI mode 0..3 */
306 if (priv->mode & SPI_CPOL)
307 ctrlr0 |= SCOL_HIGH << SCOL_SHIFT;
308 if (priv->mode & SPI_CPHA)
309 ctrlr0 |= SCPH_TOGSTA << SCPH_SHIFT;
310
311 /* Chip Select Mode */
312 ctrlr0 |= CSM_KEEP << CSM_SHIFT;
313
314 /* SSN to Sclk_out delay */
315 ctrlr0 |= SSN_DELAY_ONE << SSN_DELAY_SHIFT;
316
317 /* Serial Endian Mode */
318 ctrlr0 |= SEM_LITTLE << SEM_SHIFT;
319
320 /* First Bit Mode */
321 ctrlr0 |= FBM_MSB << FBM_SHIFT;
322
323 /* Byte and Halfword Transform */
324 ctrlr0 |= HALF_WORD_OFF << HALF_WORD_TX_SHIFT;
325
326 /* Rxd Sample Delay */
327 ctrlr0 |= 0 << RXDSD_SHIFT;
328
329 /* Frame Format */
330 ctrlr0 |= FRF_SPI << FRF_SHIFT;
331
332 /* Tx and Rx mode */
333 ctrlr0 |= TMOD_TR << TMOD_SHIFT;
334
335 writel(ctrlr0, ®s->ctrlr0);
336
337 return 0;
338 }
339
rockchip_spi_release_bus(struct udevice * dev)340 static int rockchip_spi_release_bus(struct udevice *dev)
341 {
342 struct udevice *bus = dev->parent;
343 struct rockchip_spi_priv *priv = dev_get_priv(bus);
344
345 rkspi_enable_chip(priv->regs, false);
346
347 return 0;
348 }
349
rockchip_spi_16bit_reader(struct udevice * dev,u8 ** din,int * len)350 static inline int rockchip_spi_16bit_reader(struct udevice *dev,
351 u8 **din, int *len)
352 {
353 struct udevice *bus = dev->parent;
354 const struct rockchip_spi_params * const data =
355 (void *)dev_get_driver_data(bus);
356 struct rockchip_spi_priv *priv = dev_get_priv(bus);
357 struct rockchip_spi *regs = priv->regs;
358 const u32 saved_ctrlr0 = readl(®s->ctrlr0);
359 #if defined(DEBUG)
360 u32 statistics_rxlevels[33] = { };
361 #endif
362 u32 frames = *len / 2;
363 u8 *in = (u8 *)(*din);
364 u32 max_chunk_size = SPI_FIFO_DEPTH;
365
366 if (!frames)
367 return 0;
368
369 /*
370 * If we know that the hardware will manage RXFIFO overruns
371 * (i.e. stop the SPI clock until there's space in the FIFO),
372 * we the allow largest possible chunk size that can be
373 * represented in CTRLR1.
374 */
375 if (data && data->master_manages_fifo)
376 max_chunk_size = ROCKCHIP_SPI_MAX_TRANLEN;
377
378 // rockchip_spi_configure(dev, mode, size)
379 rkspi_enable_chip(regs, false);
380 clrsetbits_le32(®s->ctrlr0,
381 TMOD_MASK << TMOD_SHIFT,
382 TMOD_RO << TMOD_SHIFT);
383 /* 16bit data frame size */
384 clrsetbits_le32(®s->ctrlr0, DFS_MASK, DFS_16BIT);
385
386 /* Update caller's context */
387 const u32 bytes_to_process = 2 * frames;
388 *din += bytes_to_process;
389 *len -= bytes_to_process;
390
391 /* Process our frames */
392 while (frames) {
393 u32 chunk_size = min(frames, max_chunk_size);
394
395 frames -= chunk_size;
396
397 writew(chunk_size - 1, ®s->ctrlr1);
398 rkspi_enable_chip(regs, true);
399
400 do {
401 u32 rx_level = readw(®s->rxflr);
402 #if defined(DEBUG)
403 statistics_rxlevels[rx_level]++;
404 #endif
405 chunk_size -= rx_level;
406 while (rx_level--) {
407 u16 val = readw(regs->rxdr);
408 *in++ = val & 0xff;
409 *in++ = val >> 8;
410 }
411 } while (chunk_size);
412
413 rkspi_enable_chip(regs, false);
414 }
415
416 #if defined(DEBUG)
417 debug("%s: observed rx_level during processing:\n", __func__);
418 for (int i = 0; i <= 32; ++i)
419 if (statistics_rxlevels[i])
420 debug("\t%2d: %d\n", i, statistics_rxlevels[i]);
421 #endif
422 /* Restore the original transfer setup and return error-free. */
423 writel(saved_ctrlr0, ®s->ctrlr0);
424 return 0;
425 }
426
rockchip_spi_xfer(struct udevice * dev,unsigned int bitlen,const void * dout,void * din,unsigned long flags)427 static int rockchip_spi_xfer(struct udevice *dev, unsigned int bitlen,
428 const void *dout, void *din, unsigned long flags)
429 {
430 struct udevice *bus = dev->parent;
431 struct rockchip_spi_priv *priv = dev_get_priv(bus);
432 struct rockchip_spi *regs = priv->regs;
433 struct dm_spi_slave_platdata *slave_plat = dev_get_parent_platdata(dev);
434 int len = bitlen >> 3;
435 const u8 *out = dout;
436 u8 *in = din;
437 int toread, towrite;
438 int ret = 0;
439
440 debug("%s: dout=%p, din=%p, len=%x, flags=%lx\n", __func__, dout, din,
441 len, flags);
442 if (DEBUG_RK_SPI)
443 rkspi_dump_regs(regs);
444
445 /* Assert CS before transfer */
446 if (flags & SPI_XFER_BEGIN)
447 spi_cs_activate(dev, slave_plat->cs);
448
449 /*
450 * To ensure fast loading of firmware images (e.g. full U-Boot
451 * stage, ATF, Linux kernel) from SPI flash, we optimise the
452 * case of read-only transfers by using the full 16bits of each
453 * FIFO element.
454 */
455 if (!out)
456 ret = rockchip_spi_16bit_reader(dev, &in, &len);
457
458 /* This is the original 8bit reader/writer code */
459 while (len > 0) {
460 int todo = min(len, ROCKCHIP_SPI_MAX_TRANLEN);
461
462 rkspi_enable_chip(regs, false);
463 writel(todo - 1, ®s->ctrlr1);
464 rkspi_enable_chip(regs, true);
465
466 toread = todo;
467 towrite = todo;
468 while (toread || towrite) {
469 u32 status = readl(®s->sr);
470
471 if (towrite && !(status & SR_TF_FULL)) {
472 writel(out ? *out++ : 0, regs->txdr);
473 towrite--;
474 }
475 if (toread && !(status & SR_RF_EMPT)) {
476 u32 byte = readl(regs->rxdr);
477
478 if (in)
479 *in++ = byte;
480 toread--;
481 }
482 }
483
484 /*
485 * In case that there's a transmit-component, we need to wait
486 * until the control goes idle before we can disable the SPI
487 * control logic (as this will implictly flush the FIFOs).
488 */
489 if (out) {
490 ret = rkspi_wait_till_not_busy(regs);
491 if (ret)
492 break;
493 }
494
495 len -= todo;
496 }
497
498 /* Deassert CS after transfer */
499 if (flags & SPI_XFER_END)
500 spi_cs_deactivate(dev, slave_plat->cs);
501
502 rkspi_enable_chip(regs, false);
503
504 return ret;
505 }
506
rockchip_spi_set_speed(struct udevice * bus,uint speed)507 static int rockchip_spi_set_speed(struct udevice *bus, uint speed)
508 {
509 struct rockchip_spi_priv *priv = dev_get_priv(bus);
510
511 /* Clamp to the maximum frequency specified in the DTS */
512 if (speed > priv->max_freq)
513 speed = priv->max_freq;
514
515 priv->speed_hz = speed;
516
517 return 0;
518 }
519
rockchip_spi_set_mode(struct udevice * bus,uint mode)520 static int rockchip_spi_set_mode(struct udevice *bus, uint mode)
521 {
522 struct rockchip_spi_priv *priv = dev_get_priv(bus);
523
524 priv->mode = mode;
525
526 return 0;
527 }
528
529 static const struct dm_spi_ops rockchip_spi_ops = {
530 .claim_bus = rockchip_spi_claim_bus,
531 .release_bus = rockchip_spi_release_bus,
532 .xfer = rockchip_spi_xfer,
533 .set_speed = rockchip_spi_set_speed,
534 .set_mode = rockchip_spi_set_mode,
535 /*
536 * cs_info is not needed, since we require all chip selects to be
537 * in the device tree explicitly
538 */
539 };
540
541 const struct rockchip_spi_params rk3399_spi_params = {
542 .master_manages_fifo = true,
543 };
544
545 static const struct udevice_id rockchip_spi_ids[] = {
546 { .compatible = "rockchip,rk3288-spi" },
547 { .compatible = "rockchip,rk3368-spi",
548 .data = (ulong)&rk3399_spi_params },
549 { .compatible = "rockchip,rk3399-spi",
550 .data = (ulong)&rk3399_spi_params },
551 { }
552 };
553
554 U_BOOT_DRIVER(rockchip_spi) = {
555 #if CONFIG_IS_ENABLED(OF_PLATDATA)
556 .name = "rockchip_rk3288_spi",
557 #else
558 .name = "rockchip_spi",
559 #endif
560 .id = UCLASS_SPI,
561 .of_match = rockchip_spi_ids,
562 .ops = &rockchip_spi_ops,
563 .ofdata_to_platdata = rockchip_spi_ofdata_to_platdata,
564 .platdata_auto_alloc_size = sizeof(struct rockchip_spi_platdata),
565 .priv_auto_alloc_size = sizeof(struct rockchip_spi_priv),
566 .probe = rockchip_spi_probe,
567 };
568