1 // SPDX-License-Identifier: GPL-2.0+
3 * spi driver for rockchip
5 * (C) Copyright 2015 Google, Inc
7 * (C) Copyright 2008-2013 Rockchip Electronics
8 * Peter, Software Engineering, <superpeter.cai@gmail.com>.
14 #include <dt-structs.h>
17 #include <linux/errno.h>
19 #include <asm/arch/clock.h>
20 #include <asm/arch/periph.h>
21 #include <dm/pinctrl.h>
24 /* Change to 1 to output registers at the start of each transaction */
25 #define DEBUG_RK_SPI 0
27 struct rockchip_spi_platdata {
28 #if CONFIG_IS_ENABLED(OF_PLATDATA)
29 struct dtd_rockchip_rk3288_spi of_plat;
31 s32 frequency; /* Default clock frequency, -1 for none */
33 uint deactivate_delay_us; /* Delay to wait after deactivate */
34 uint activate_delay_us; /* Delay to wait after activate */
37 struct rockchip_spi_priv {
38 struct rockchip_spi *regs;
40 unsigned int max_freq;
42 ulong last_transaction_us; /* Time of last transaction end */
43 u8 bits_per_word; /* max 16 bits per word */
45 unsigned int speed_hz;
46 unsigned int last_speed_hz;
51 #define SPI_FIFO_DEPTH 32
53 static void rkspi_dump_regs(struct rockchip_spi *regs)
55 debug("ctrl0: \t\t0x%08x\n", readl(®s->ctrlr0));
56 debug("ctrl1: \t\t0x%08x\n", readl(®s->ctrlr1));
57 debug("ssienr: \t\t0x%08x\n", readl(®s->enr));
58 debug("ser: \t\t0x%08x\n", readl(®s->ser));
59 debug("baudr: \t\t0x%08x\n", readl(®s->baudr));
60 debug("txftlr: \t\t0x%08x\n", readl(®s->txftlr));
61 debug("rxftlr: \t\t0x%08x\n", readl(®s->rxftlr));
62 debug("txflr: \t\t0x%08x\n", readl(®s->txflr));
63 debug("rxflr: \t\t0x%08x\n", readl(®s->rxflr));
64 debug("sr: \t\t0x%08x\n", readl(®s->sr));
65 debug("imr: \t\t0x%08x\n", readl(®s->imr));
66 debug("isr: \t\t0x%08x\n", readl(®s->isr));
67 debug("dmacr: \t\t0x%08x\n", readl(®s->dmacr));
68 debug("dmatdlr: \t0x%08x\n", readl(®s->dmatdlr));
69 debug("dmardlr: \t0x%08x\n", readl(®s->dmardlr));
72 static void rkspi_enable_chip(struct rockchip_spi *regs, bool enable)
74 writel(enable ? 1 : 0, ®s->enr);
77 static void rkspi_set_clk(struct rockchip_spi_priv *priv, uint speed)
80 * We should try not to exceed the speed requested by the caller:
81 * when selecting a divider, we need to make sure we round up.
83 uint clk_div = DIV_ROUND_UP(priv->input_rate, speed);
85 /* The baudrate register (BAUDR) is defined as a 32bit register where
86 * the upper 16bit are reserved and having 'Fsclk_out' in the lower
87 * 16bits with 'Fsclk_out' defined as follows:
89 * Fsclk_out = Fspi_clk/ SCKDV
90 * Where SCKDV is any even value between 2 and 65534.
92 if (clk_div > 0xfffe) {
94 debug("%s: can't divide down to %d Hz (actual will be %d Hz)\n",
95 __func__, speed, priv->input_rate / clk_div);
98 /* Round up to the next even 16bit number */
99 clk_div = (clk_div + 1) & 0xfffe;
101 debug("spi speed %u, div %u\n", speed, clk_div);
103 clrsetbits_le32(&priv->regs->baudr, 0xffff, clk_div);
104 priv->last_speed_hz = speed;
107 static int rkspi_wait_till_not_busy(struct rockchip_spi *regs)
111 start = get_timer(0);
112 while (readl(®s->sr) & SR_BUSY) {
113 if (get_timer(start) > ROCKCHIP_SPI_TIMEOUT_MS) {
114 debug("RK SPI: Status keeps busy for 1000us after a read/write!\n");
122 static void spi_cs_activate(struct udevice *dev, uint cs)
124 struct udevice *bus = dev->parent;
125 struct rockchip_spi_platdata *plat = bus->platdata;
126 struct rockchip_spi_priv *priv = dev_get_priv(bus);
127 struct rockchip_spi *regs = priv->regs;
129 /* If it's too soon to do another transaction, wait */
130 if (plat->deactivate_delay_us && priv->last_transaction_us) {
131 ulong delay_us; /* The delay completed so far */
132 delay_us = timer_get_us() - priv->last_transaction_us;
133 if (delay_us < plat->deactivate_delay_us) {
134 ulong additional_delay_us =
135 plat->deactivate_delay_us - delay_us;
136 debug("%s: delaying by %ld us\n",
137 __func__, additional_delay_us);
138 udelay(additional_delay_us);
142 debug("activate cs%u\n", cs);
143 writel(1 << cs, ®s->ser);
144 if (plat->activate_delay_us)
145 udelay(plat->activate_delay_us);
148 static void spi_cs_deactivate(struct udevice *dev, uint cs)
150 struct udevice *bus = dev->parent;
151 struct rockchip_spi_platdata *plat = bus->platdata;
152 struct rockchip_spi_priv *priv = dev_get_priv(bus);
153 struct rockchip_spi *regs = priv->regs;
155 debug("deactivate cs%u\n", cs);
156 writel(0, ®s->ser);
158 /* Remember time of this transaction so we can honour the bus delay */
159 if (plat->deactivate_delay_us)
160 priv->last_transaction_us = timer_get_us();
163 #if CONFIG_IS_ENABLED(OF_PLATDATA)
164 static int conv_of_platdata(struct udevice *dev)
166 struct rockchip_spi_platdata *plat = dev->platdata;
167 struct dtd_rockchip_rk3288_spi *dtplat = &plat->of_plat;
168 struct rockchip_spi_priv *priv = dev_get_priv(dev);
171 plat->base = dtplat->reg[0];
172 plat->frequency = 20000000;
173 ret = clk_get_by_index_platdata(dev, 0, dtplat->clocks, &priv->clk);
182 static int rockchip_spi_ofdata_to_platdata(struct udevice *bus)
184 #if !CONFIG_IS_ENABLED(OF_PLATDATA)
185 struct rockchip_spi_platdata *plat = dev_get_platdata(bus);
186 struct rockchip_spi_priv *priv = dev_get_priv(bus);
189 plat->base = dev_read_addr(bus);
191 ret = clk_get_by_index(bus, 0, &priv->clk);
193 debug("%s: Could not get clock for %s: %d\n", __func__,
199 dev_read_u32_default(bus, "spi-max-frequency", 50000000);
200 plat->deactivate_delay_us =
201 dev_read_u32_default(bus, "spi-deactivate-delay", 0);
202 plat->activate_delay_us =
203 dev_read_u32_default(bus, "spi-activate-delay", 0);
205 debug("%s: base=%x, max-frequency=%d, deactivate_delay=%d\n",
206 __func__, (uint)plat->base, plat->frequency,
207 plat->deactivate_delay_us);
213 static int rockchip_spi_calc_modclk(ulong max_freq)
216 * While this is not strictly correct for the RK3368, as the
217 * GPLL will be 576MHz, things will still work, as the
218 * clk_set_rate(...) implementation in our clock-driver will
219 * chose the next closest rate not exceeding what we request
220 * based on the output of this function.
224 const unsigned long gpll_hz = 594000000UL;
227 * We need to find an input clock that provides at least twice
228 * the maximum frequency and can be generated from the assumed
229 * speed of GPLL (594MHz) using an integer divider.
231 * To give us more achievable bitrates at higher speeds (these
232 * are generated by dividing by an even 16-bit integer from
233 * this frequency), we try to have an input frequency of at
234 * least 4x our max_freq.
237 div = DIV_ROUND_UP(gpll_hz, max_freq * 4);
238 return gpll_hz / div;
241 static int rockchip_spi_probe(struct udevice *bus)
243 struct rockchip_spi_platdata *plat = dev_get_platdata(bus);
244 struct rockchip_spi_priv *priv = dev_get_priv(bus);
247 debug("%s: probe\n", __func__);
248 #if CONFIG_IS_ENABLED(OF_PLATDATA)
249 ret = conv_of_platdata(bus);
253 priv->regs = (struct rockchip_spi *)plat->base;
255 priv->last_transaction_us = timer_get_us();
256 priv->max_freq = plat->frequency;
258 /* Clamp the value from the DTS against any hardware limits */
259 if (priv->max_freq > ROCKCHIP_SPI_MAX_RATE)
260 priv->max_freq = ROCKCHIP_SPI_MAX_RATE;
262 /* Find a module-input clock that fits with the max_freq setting */
263 ret = clk_set_rate(&priv->clk,
264 rockchip_spi_calc_modclk(priv->max_freq));
266 debug("%s: Failed to set clock: %d\n", __func__, ret);
269 priv->input_rate = ret;
270 debug("%s: rate = %u\n", __func__, priv->input_rate);
271 priv->bits_per_word = 8;
272 priv->tmode = TMOD_TR; /* Tx & Rx */
277 static int rockchip_spi_claim_bus(struct udevice *dev)
279 struct udevice *bus = dev->parent;
280 struct rockchip_spi_priv *priv = dev_get_priv(bus);
281 struct rockchip_spi *regs = priv->regs;
285 /* Disable the SPI hardware */
286 rkspi_enable_chip(regs, 0);
288 switch (priv->bits_per_word) {
292 spi_tf = HALF_WORD_OFF;
297 spi_tf = HALF_WORD_ON;
300 debug("%s: unsupported bits: %dbits\n", __func__,
301 priv->bits_per_word);
302 return -EPROTONOSUPPORT;
305 if (priv->speed_hz != priv->last_speed_hz)
306 rkspi_set_clk(priv, priv->speed_hz);
309 ctrlr0 = OMOD_MASTER << OMOD_SHIFT;
311 /* Data Frame Size */
312 ctrlr0 |= spi_dfs << DFS_SHIFT;
314 /* set SPI mode 0..3 */
315 if (priv->mode & SPI_CPOL)
316 ctrlr0 |= SCOL_HIGH << SCOL_SHIFT;
317 if (priv->mode & SPI_CPHA)
318 ctrlr0 |= SCPH_TOGSTA << SCPH_SHIFT;
320 /* Chip Select Mode */
321 ctrlr0 |= CSM_KEEP << CSM_SHIFT;
323 /* SSN to Sclk_out delay */
324 ctrlr0 |= SSN_DELAY_ONE << SSN_DELAY_SHIFT;
326 /* Serial Endian Mode */
327 ctrlr0 |= SEM_LITTLE << SEM_SHIFT;
330 ctrlr0 |= FBM_MSB << FBM_SHIFT;
332 /* Byte and Halfword Transform */
333 ctrlr0 |= spi_tf << HALF_WORD_TX_SHIFT;
335 /* Rxd Sample Delay */
336 ctrlr0 |= 0 << RXDSD_SHIFT;
339 ctrlr0 |= FRF_SPI << FRF_SHIFT;
342 ctrlr0 |= (priv->tmode & TMOD_MASK) << TMOD_SHIFT;
344 writel(ctrlr0, ®s->ctrlr0);
349 static int rockchip_spi_release_bus(struct udevice *dev)
351 struct udevice *bus = dev->parent;
352 struct rockchip_spi_priv *priv = dev_get_priv(bus);
354 rkspi_enable_chip(priv->regs, false);
359 static int rockchip_spi_xfer(struct udevice *dev, unsigned int bitlen,
360 const void *dout, void *din, unsigned long flags)
362 struct udevice *bus = dev->parent;
363 struct rockchip_spi_priv *priv = dev_get_priv(bus);
364 struct rockchip_spi *regs = priv->regs;
365 struct dm_spi_slave_platdata *slave_plat = dev_get_parent_platdata(dev);
366 int len = bitlen >> 3;
367 const u8 *out = dout;
372 debug("%s: dout=%p, din=%p, len=%x, flags=%lx\n", __func__, dout, din,
375 rkspi_dump_regs(regs);
377 /* Assert CS before transfer */
378 if (flags & SPI_XFER_BEGIN)
379 spi_cs_activate(dev, slave_plat->cs);
382 int todo = min(len, 0xffff);
384 rkspi_enable_chip(regs, false);
385 writel(todo - 1, ®s->ctrlr1);
386 rkspi_enable_chip(regs, true);
390 while (toread || towrite) {
391 u32 status = readl(®s->sr);
393 if (towrite && !(status & SR_TF_FULL)) {
394 writel(out ? *out++ : 0, regs->txdr);
397 if (toread && !(status & SR_RF_EMPT)) {
398 u32 byte = readl(regs->rxdr);
405 ret = rkspi_wait_till_not_busy(regs);
411 /* Deassert CS after transfer */
412 if (flags & SPI_XFER_END)
413 spi_cs_deactivate(dev, slave_plat->cs);
415 rkspi_enable_chip(regs, false);
420 static int rockchip_spi_set_speed(struct udevice *bus, uint speed)
422 struct rockchip_spi_priv *priv = dev_get_priv(bus);
424 /* Clamp to the maximum frequency specified in the DTS */
425 if (speed > priv->max_freq)
426 speed = priv->max_freq;
428 priv->speed_hz = speed;
433 static int rockchip_spi_set_mode(struct udevice *bus, uint mode)
435 struct rockchip_spi_priv *priv = dev_get_priv(bus);
442 static const struct dm_spi_ops rockchip_spi_ops = {
443 .claim_bus = rockchip_spi_claim_bus,
444 .release_bus = rockchip_spi_release_bus,
445 .xfer = rockchip_spi_xfer,
446 .set_speed = rockchip_spi_set_speed,
447 .set_mode = rockchip_spi_set_mode,
449 * cs_info is not needed, since we require all chip selects to be
450 * in the device tree explicitly
454 static const struct udevice_id rockchip_spi_ids[] = {
455 { .compatible = "rockchip,rk3288-spi" },
456 { .compatible = "rockchip,rk3368-spi" },
457 { .compatible = "rockchip,rk3399-spi" },
461 U_BOOT_DRIVER(rockchip_spi) = {
462 #if CONFIG_IS_ENABLED(OF_PLATDATA)
463 .name = "rockchip_rk3288_spi",
465 .name = "rockchip_spi",
468 .of_match = rockchip_spi_ids,
469 .ops = &rockchip_spi_ops,
470 .ofdata_to_platdata = rockchip_spi_ofdata_to_platdata,
471 .platdata_auto_alloc_size = sizeof(struct rockchip_spi_platdata),
472 .priv_auto_alloc_size = sizeof(struct rockchip_spi_priv),
473 .probe = rockchip_spi_probe,