1 // SPDX-License-Identifier: GPL-2.0+
3 * spi driver for rockchip
5 * (C) 2019 Theobroma Systems Design und Consulting GmbH
7 * (C) Copyright 2015 Google, Inc
9 * (C) Copyright 2008-2013 Rockchip Electronics
10 * Peter, Software Engineering, <superpeter.cai@gmail.com>.
16 #include <dt-structs.h>
21 #include <linux/delay.h>
22 #include <linux/errno.h>
24 #include <asm/arch-rockchip/clock.h>
25 #include <asm/arch-rockchip/periph.h>
26 #include <dm/pinctrl.h>
29 /* Change to 1 to output registers at the start of each transaction */
30 #define DEBUG_RK_SPI 0
33 * ctrlr1 is 16-bits, so we should support lengths of 0xffff + 1. However,
34 * the controller seems to hang when given 0x10000, so stick with this for now.
36 #define ROCKCHIP_SPI_MAX_TRANLEN 0xffff
38 struct rockchip_spi_params {
39 /* RXFIFO overruns and TXFIFO underruns stop the master clock */
40 bool master_manages_fifo;
43 struct rockchip_spi_platdata {
44 #if CONFIG_IS_ENABLED(OF_PLATDATA)
45 struct dtd_rockchip_rk3288_spi of_plat;
47 s32 frequency; /* Default clock frequency, -1 for none */
49 uint deactivate_delay_us; /* Delay to wait after deactivate */
50 uint activate_delay_us; /* Delay to wait after activate */
53 struct rockchip_spi_priv {
54 struct rockchip_spi *regs;
56 unsigned int max_freq;
58 ulong last_transaction_us; /* Time of last transaction end */
59 unsigned int speed_hz;
60 unsigned int last_speed_hz;
64 #define SPI_FIFO_DEPTH 32
66 static void rkspi_dump_regs(struct rockchip_spi *regs)
68 debug("ctrl0: \t\t0x%08x\n", readl(®s->ctrlr0));
69 debug("ctrl1: \t\t0x%08x\n", readl(®s->ctrlr1));
70 debug("ssienr: \t\t0x%08x\n", readl(®s->enr));
71 debug("ser: \t\t0x%08x\n", readl(®s->ser));
72 debug("baudr: \t\t0x%08x\n", readl(®s->baudr));
73 debug("txftlr: \t\t0x%08x\n", readl(®s->txftlr));
74 debug("rxftlr: \t\t0x%08x\n", readl(®s->rxftlr));
75 debug("txflr: \t\t0x%08x\n", readl(®s->txflr));
76 debug("rxflr: \t\t0x%08x\n", readl(®s->rxflr));
77 debug("sr: \t\t0x%08x\n", readl(®s->sr));
78 debug("imr: \t\t0x%08x\n", readl(®s->imr));
79 debug("isr: \t\t0x%08x\n", readl(®s->isr));
80 debug("dmacr: \t\t0x%08x\n", readl(®s->dmacr));
81 debug("dmatdlr: \t0x%08x\n", readl(®s->dmatdlr));
82 debug("dmardlr: \t0x%08x\n", readl(®s->dmardlr));
85 static void rkspi_enable_chip(struct rockchip_spi *regs, bool enable)
87 writel(enable ? 1 : 0, ®s->enr);
90 static void rkspi_set_clk(struct rockchip_spi_priv *priv, uint speed)
93 * We should try not to exceed the speed requested by the caller:
94 * when selecting a divider, we need to make sure we round up.
96 uint clk_div = DIV_ROUND_UP(priv->input_rate, speed);
98 /* The baudrate register (BAUDR) is defined as a 32bit register where
99 * the upper 16bit are reserved and having 'Fsclk_out' in the lower
100 * 16bits with 'Fsclk_out' defined as follows:
102 * Fsclk_out = Fspi_clk/ SCKDV
103 * Where SCKDV is any even value between 2 and 65534.
105 if (clk_div > 0xfffe) {
107 debug("%s: can't divide down to %d Hz (actual will be %d Hz)\n",
108 __func__, speed, priv->input_rate / clk_div);
111 /* Round up to the next even 16bit number */
112 clk_div = (clk_div + 1) & 0xfffe;
114 debug("spi speed %u, div %u\n", speed, clk_div);
116 clrsetbits_le32(&priv->regs->baudr, 0xffff, clk_div);
117 priv->last_speed_hz = speed;
120 static int rkspi_wait_till_not_busy(struct rockchip_spi *regs)
124 start = get_timer(0);
125 while (readl(®s->sr) & SR_BUSY) {
126 if (get_timer(start) > ROCKCHIP_SPI_TIMEOUT_MS) {
127 debug("RK SPI: Status keeps busy for 1000us after a read/write!\n");
135 static void spi_cs_activate(struct udevice *dev, uint cs)
137 struct udevice *bus = dev->parent;
138 struct rockchip_spi_platdata *plat = bus->platdata;
139 struct rockchip_spi_priv *priv = dev_get_priv(bus);
140 struct rockchip_spi *regs = priv->regs;
142 /* If it's too soon to do another transaction, wait */
143 if (plat->deactivate_delay_us && priv->last_transaction_us) {
144 ulong delay_us; /* The delay completed so far */
145 delay_us = timer_get_us() - priv->last_transaction_us;
146 if (delay_us < plat->deactivate_delay_us) {
147 ulong additional_delay_us =
148 plat->deactivate_delay_us - delay_us;
149 debug("%s: delaying by %ld us\n",
150 __func__, additional_delay_us);
151 udelay(additional_delay_us);
155 debug("activate cs%u\n", cs);
156 writel(1 << cs, ®s->ser);
157 if (plat->activate_delay_us)
158 udelay(plat->activate_delay_us);
161 static void spi_cs_deactivate(struct udevice *dev, uint cs)
163 struct udevice *bus = dev->parent;
164 struct rockchip_spi_platdata *plat = bus->platdata;
165 struct rockchip_spi_priv *priv = dev_get_priv(bus);
166 struct rockchip_spi *regs = priv->regs;
168 debug("deactivate cs%u\n", cs);
169 writel(0, ®s->ser);
171 /* Remember time of this transaction so we can honour the bus delay */
172 if (plat->deactivate_delay_us)
173 priv->last_transaction_us = timer_get_us();
176 #if CONFIG_IS_ENABLED(OF_PLATDATA)
177 static int conv_of_platdata(struct udevice *dev)
179 struct rockchip_spi_platdata *plat = dev->platdata;
180 struct dtd_rockchip_rk3288_spi *dtplat = &plat->of_plat;
181 struct rockchip_spi_priv *priv = dev_get_priv(dev);
184 plat->base = dtplat->reg[0];
185 plat->frequency = 20000000;
186 ret = clk_get_by_driver_info(dev, dtplat->clocks, &priv->clk);
195 static int rockchip_spi_ofdata_to_platdata(struct udevice *bus)
197 #if !CONFIG_IS_ENABLED(OF_PLATDATA)
198 struct rockchip_spi_platdata *plat = dev_get_platdata(bus);
199 struct rockchip_spi_priv *priv = dev_get_priv(bus);
202 plat->base = dev_read_addr(bus);
204 ret = clk_get_by_index(bus, 0, &priv->clk);
206 debug("%s: Could not get clock for %s: %d\n", __func__,
212 dev_read_u32_default(bus, "spi-max-frequency", 50000000);
213 plat->deactivate_delay_us =
214 dev_read_u32_default(bus, "spi-deactivate-delay", 0);
215 plat->activate_delay_us =
216 dev_read_u32_default(bus, "spi-activate-delay", 0);
218 debug("%s: base=%x, max-frequency=%d, deactivate_delay=%d\n",
219 __func__, (uint)plat->base, plat->frequency,
220 plat->deactivate_delay_us);
226 static int rockchip_spi_calc_modclk(ulong max_freq)
229 * While this is not strictly correct for the RK3368, as the
230 * GPLL will be 576MHz, things will still work, as the
231 * clk_set_rate(...) implementation in our clock-driver will
232 * chose the next closest rate not exceeding what we request
233 * based on the output of this function.
237 const unsigned long gpll_hz = 594000000UL;
240 * We need to find an input clock that provides at least twice
241 * the maximum frequency and can be generated from the assumed
242 * speed of GPLL (594MHz) using an integer divider.
244 * To give us more achievable bitrates at higher speeds (these
245 * are generated by dividing by an even 16-bit integer from
246 * this frequency), we try to have an input frequency of at
247 * least 4x our max_freq.
250 div = DIV_ROUND_UP(gpll_hz, max_freq * 4);
251 return gpll_hz / div;
254 static int rockchip_spi_probe(struct udevice *bus)
256 struct rockchip_spi_platdata *plat = dev_get_platdata(bus);
257 struct rockchip_spi_priv *priv = dev_get_priv(bus);
260 debug("%s: probe\n", __func__);
261 #if CONFIG_IS_ENABLED(OF_PLATDATA)
262 ret = conv_of_platdata(bus);
266 priv->regs = (struct rockchip_spi *)plat->base;
268 priv->last_transaction_us = timer_get_us();
269 priv->max_freq = plat->frequency;
271 /* Clamp the value from the DTS against any hardware limits */
272 if (priv->max_freq > ROCKCHIP_SPI_MAX_RATE)
273 priv->max_freq = ROCKCHIP_SPI_MAX_RATE;
275 /* Find a module-input clock that fits with the max_freq setting */
276 ret = clk_set_rate(&priv->clk,
277 rockchip_spi_calc_modclk(priv->max_freq));
279 debug("%s: Failed to set clock: %d\n", __func__, ret);
282 priv->input_rate = ret;
283 debug("%s: rate = %u\n", __func__, priv->input_rate);
288 static int rockchip_spi_claim_bus(struct udevice *dev)
290 struct udevice *bus = dev->parent;
291 struct rockchip_spi_priv *priv = dev_get_priv(bus);
292 struct rockchip_spi *regs = priv->regs;
295 /* Disable the SPI hardware */
296 rkspi_enable_chip(regs, false);
298 if (priv->speed_hz != priv->last_speed_hz)
299 rkspi_set_clk(priv, priv->speed_hz);
302 ctrlr0 = OMOD_MASTER << OMOD_SHIFT;
304 /* Data Frame Size */
305 ctrlr0 |= DFS_8BIT << DFS_SHIFT;
307 /* set SPI mode 0..3 */
308 if (priv->mode & SPI_CPOL)
309 ctrlr0 |= SCOL_HIGH << SCOL_SHIFT;
310 if (priv->mode & SPI_CPHA)
311 ctrlr0 |= SCPH_TOGSTA << SCPH_SHIFT;
313 /* Chip Select Mode */
314 ctrlr0 |= CSM_KEEP << CSM_SHIFT;
316 /* SSN to Sclk_out delay */
317 ctrlr0 |= SSN_DELAY_ONE << SSN_DELAY_SHIFT;
319 /* Serial Endian Mode */
320 ctrlr0 |= SEM_LITTLE << SEM_SHIFT;
323 ctrlr0 |= FBM_MSB << FBM_SHIFT;
325 /* Byte and Halfword Transform */
326 ctrlr0 |= HALF_WORD_OFF << HALF_WORD_TX_SHIFT;
328 /* Rxd Sample Delay */
329 ctrlr0 |= 0 << RXDSD_SHIFT;
332 ctrlr0 |= FRF_SPI << FRF_SHIFT;
335 ctrlr0 |= TMOD_TR << TMOD_SHIFT;
337 writel(ctrlr0, ®s->ctrlr0);
342 static int rockchip_spi_release_bus(struct udevice *dev)
344 struct udevice *bus = dev->parent;
345 struct rockchip_spi_priv *priv = dev_get_priv(bus);
347 rkspi_enable_chip(priv->regs, false);
352 static inline int rockchip_spi_16bit_reader(struct udevice *dev,
355 struct udevice *bus = dev->parent;
356 const struct rockchip_spi_params * const data =
357 (void *)dev_get_driver_data(bus);
358 struct rockchip_spi_priv *priv = dev_get_priv(bus);
359 struct rockchip_spi *regs = priv->regs;
360 const u32 saved_ctrlr0 = readl(®s->ctrlr0);
362 u32 statistics_rxlevels[33] = { };
364 u32 frames = *len / 2;
365 u8 *in = (u8 *)(*din);
366 u32 max_chunk_size = SPI_FIFO_DEPTH;
372 * If we know that the hardware will manage RXFIFO overruns
373 * (i.e. stop the SPI clock until there's space in the FIFO),
374 * we the allow largest possible chunk size that can be
375 * represented in CTRLR1.
377 if (data && data->master_manages_fifo)
378 max_chunk_size = ROCKCHIP_SPI_MAX_TRANLEN;
380 // rockchip_spi_configure(dev, mode, size)
381 rkspi_enable_chip(regs, false);
382 clrsetbits_le32(®s->ctrlr0,
383 TMOD_MASK << TMOD_SHIFT,
384 TMOD_RO << TMOD_SHIFT);
385 /* 16bit data frame size */
386 clrsetbits_le32(®s->ctrlr0, DFS_MASK, DFS_16BIT);
388 /* Update caller's context */
389 const u32 bytes_to_process = 2 * frames;
390 *din += bytes_to_process;
391 *len -= bytes_to_process;
393 /* Process our frames */
395 u32 chunk_size = min(frames, max_chunk_size);
397 frames -= chunk_size;
399 writew(chunk_size - 1, ®s->ctrlr1);
400 rkspi_enable_chip(regs, true);
403 u32 rx_level = readw(®s->rxflr);
405 statistics_rxlevels[rx_level]++;
407 chunk_size -= rx_level;
409 u16 val = readw(regs->rxdr);
413 } while (chunk_size);
415 rkspi_enable_chip(regs, false);
419 debug("%s: observed rx_level during processing:\n", __func__);
420 for (int i = 0; i <= 32; ++i)
421 if (statistics_rxlevels[i])
422 debug("\t%2d: %d\n", i, statistics_rxlevels[i]);
424 /* Restore the original transfer setup and return error-free. */
425 writel(saved_ctrlr0, ®s->ctrlr0);
429 static int rockchip_spi_xfer(struct udevice *dev, unsigned int bitlen,
430 const void *dout, void *din, unsigned long flags)
432 struct udevice *bus = dev->parent;
433 struct rockchip_spi_priv *priv = dev_get_priv(bus);
434 struct rockchip_spi *regs = priv->regs;
435 struct dm_spi_slave_platdata *slave_plat = dev_get_parent_platdata(dev);
436 int len = bitlen >> 3;
437 const u8 *out = dout;
442 debug("%s: dout=%p, din=%p, len=%x, flags=%lx\n", __func__, dout, din,
445 rkspi_dump_regs(regs);
447 /* Assert CS before transfer */
448 if (flags & SPI_XFER_BEGIN)
449 spi_cs_activate(dev, slave_plat->cs);
452 * To ensure fast loading of firmware images (e.g. full U-Boot
453 * stage, ATF, Linux kernel) from SPI flash, we optimise the
454 * case of read-only transfers by using the full 16bits of each
458 ret = rockchip_spi_16bit_reader(dev, &in, &len);
460 /* This is the original 8bit reader/writer code */
462 int todo = min(len, ROCKCHIP_SPI_MAX_TRANLEN);
464 rkspi_enable_chip(regs, false);
465 writel(todo - 1, ®s->ctrlr1);
466 rkspi_enable_chip(regs, true);
470 while (toread || towrite) {
471 u32 status = readl(®s->sr);
473 if (towrite && !(status & SR_TF_FULL)) {
474 writel(out ? *out++ : 0, regs->txdr);
477 if (toread && !(status & SR_RF_EMPT)) {
478 u32 byte = readl(regs->rxdr);
487 * In case that there's a transmit-component, we need to wait
488 * until the control goes idle before we can disable the SPI
489 * control logic (as this will implictly flush the FIFOs).
492 ret = rkspi_wait_till_not_busy(regs);
500 /* Deassert CS after transfer */
501 if (flags & SPI_XFER_END)
502 spi_cs_deactivate(dev, slave_plat->cs);
504 rkspi_enable_chip(regs, false);
509 static int rockchip_spi_set_speed(struct udevice *bus, uint speed)
511 struct rockchip_spi_priv *priv = dev_get_priv(bus);
513 /* Clamp to the maximum frequency specified in the DTS */
514 if (speed > priv->max_freq)
515 speed = priv->max_freq;
517 priv->speed_hz = speed;
522 static int rockchip_spi_set_mode(struct udevice *bus, uint mode)
524 struct rockchip_spi_priv *priv = dev_get_priv(bus);
531 static const struct dm_spi_ops rockchip_spi_ops = {
532 .claim_bus = rockchip_spi_claim_bus,
533 .release_bus = rockchip_spi_release_bus,
534 .xfer = rockchip_spi_xfer,
535 .set_speed = rockchip_spi_set_speed,
536 .set_mode = rockchip_spi_set_mode,
538 * cs_info is not needed, since we require all chip selects to be
539 * in the device tree explicitly
543 const struct rockchip_spi_params rk3399_spi_params = {
544 .master_manages_fifo = true,
547 static const struct udevice_id rockchip_spi_ids[] = {
548 { .compatible = "rockchip,rk3066-spi" },
549 { .compatible = "rockchip,rk3288-spi" },
550 { .compatible = "rockchip,rk3328-spi" },
551 { .compatible = "rockchip,rk3368-spi",
552 .data = (ulong)&rk3399_spi_params },
553 { .compatible = "rockchip,rk3399-spi",
554 .data = (ulong)&rk3399_spi_params },
558 U_BOOT_DRIVER(rockchip_rk3288_spi) = {
559 .name = "rockchip_rk3288_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,
569 U_BOOT_DRIVER_ALIAS(rockchip_rk3288_spi, rockchip_rk3368_spi)