1 /* 2 * spi driver for rockchip 3 * 4 * (C) Copyright 2015 Google, Inc 5 * 6 * (C) Copyright 2008-2013 Rockchip Electronics 7 * Peter, Software Engineering, <superpeter.cai@gmail.com>. 8 * 9 * SPDX-License-Identifier: GPL-2.0+ 10 */ 11 12 #include <common.h> 13 #include <clk.h> 14 #include <dm.h> 15 #include <errno.h> 16 #include <spi.h> 17 #include <linux/errno.h> 18 #include <asm/io.h> 19 #include <asm/arch/clock.h> 20 #include <asm/arch/periph.h> 21 #include <dm/pinctrl.h> 22 #include "rk_spi.h" 23 24 DECLARE_GLOBAL_DATA_PTR; 25 26 /* Change to 1 to output registers at the start of each transaction */ 27 #define DEBUG_RK_SPI 0 28 29 struct rockchip_spi_platdata { 30 s32 frequency; /* Default clock frequency, -1 for none */ 31 fdt_addr_t base; 32 uint deactivate_delay_us; /* Delay to wait after deactivate */ 33 uint activate_delay_us; /* Delay to wait after activate */ 34 }; 35 36 struct rockchip_spi_priv { 37 struct rockchip_spi *regs; 38 struct clk clk; 39 unsigned int max_freq; 40 unsigned int mode; 41 ulong last_transaction_us; /* Time of last transaction end */ 42 u8 bits_per_word; /* max 16 bits per word */ 43 u8 n_bytes; 44 unsigned int speed_hz; 45 unsigned int last_speed_hz; 46 unsigned int tmode; 47 uint input_rate; 48 }; 49 50 #define SPI_FIFO_DEPTH 32 51 52 static void rkspi_dump_regs(struct rockchip_spi *regs) 53 { 54 debug("ctrl0: \t\t0x%08x\n", readl(®s->ctrlr0)); 55 debug("ctrl1: \t\t0x%08x\n", readl(®s->ctrlr1)); 56 debug("ssienr: \t\t0x%08x\n", readl(®s->enr)); 57 debug("ser: \t\t0x%08x\n", readl(®s->ser)); 58 debug("baudr: \t\t0x%08x\n", readl(®s->baudr)); 59 debug("txftlr: \t\t0x%08x\n", readl(®s->txftlr)); 60 debug("rxftlr: \t\t0x%08x\n", readl(®s->rxftlr)); 61 debug("txflr: \t\t0x%08x\n", readl(®s->txflr)); 62 debug("rxflr: \t\t0x%08x\n", readl(®s->rxflr)); 63 debug("sr: \t\t0x%08x\n", readl(®s->sr)); 64 debug("imr: \t\t0x%08x\n", readl(®s->imr)); 65 debug("isr: \t\t0x%08x\n", readl(®s->isr)); 66 debug("dmacr: \t\t0x%08x\n", readl(®s->dmacr)); 67 debug("dmatdlr: \t0x%08x\n", readl(®s->dmatdlr)); 68 debug("dmardlr: \t0x%08x\n", readl(®s->dmardlr)); 69 } 70 71 static void rkspi_enable_chip(struct rockchip_spi *regs, bool enable) 72 { 73 writel(enable ? 1 : 0, ®s->enr); 74 } 75 76 static void rkspi_set_clk(struct rockchip_spi_priv *priv, uint speed) 77 { 78 uint clk_div; 79 80 clk_div = clk_get_divisor(priv->input_rate, speed); 81 debug("spi speed %u, div %u\n", speed, clk_div); 82 83 writel(clk_div, &priv->regs->baudr); 84 priv->last_speed_hz = speed; 85 } 86 87 static int rkspi_wait_till_not_busy(struct rockchip_spi *regs) 88 { 89 unsigned long start; 90 91 start = get_timer(0); 92 while (readl(®s->sr) & SR_BUSY) { 93 if (get_timer(start) > ROCKCHIP_SPI_TIMEOUT_MS) { 94 debug("RK SPI: Status keeps busy for 1000us after a read/write!\n"); 95 return -ETIMEDOUT; 96 } 97 } 98 99 return 0; 100 } 101 102 static void spi_cs_activate(struct udevice *dev, uint cs) 103 { 104 struct udevice *bus = dev->parent; 105 struct rockchip_spi_platdata *plat = bus->platdata; 106 struct rockchip_spi_priv *priv = dev_get_priv(bus); 107 struct rockchip_spi *regs = priv->regs; 108 109 debug("activate cs%u\n", cs); 110 writel(1 << cs, ®s->ser); 111 if (plat->activate_delay_us) 112 udelay(plat->activate_delay_us); 113 } 114 115 static void spi_cs_deactivate(struct udevice *dev, uint cs) 116 { 117 struct udevice *bus = dev->parent; 118 struct rockchip_spi_platdata *plat = bus->platdata; 119 struct rockchip_spi_priv *priv = dev_get_priv(bus); 120 struct rockchip_spi *regs = priv->regs; 121 122 debug("deactivate cs%u\n", cs); 123 writel(0, ®s->ser); 124 125 /* Remember time of this transaction so we can honour the bus delay */ 126 if (plat->deactivate_delay_us) 127 priv->last_transaction_us = timer_get_us(); 128 } 129 130 static int rockchip_spi_ofdata_to_platdata(struct udevice *bus) 131 { 132 struct rockchip_spi_platdata *plat = bus->platdata; 133 struct rockchip_spi_priv *priv = dev_get_priv(bus); 134 const void *blob = gd->fdt_blob; 135 int node = bus->of_offset; 136 int ret; 137 138 plat->base = dev_get_addr(bus); 139 140 ret = clk_get_by_index(bus, 0, &priv->clk); 141 if (ret < 0) { 142 debug("%s: Could not get clock for %s: %d\n", __func__, 143 bus->name, ret); 144 return ret; 145 } 146 147 plat->frequency = fdtdec_get_int(blob, node, "spi-max-frequency", 148 50000000); 149 plat->deactivate_delay_us = fdtdec_get_int(blob, node, 150 "spi-deactivate-delay", 0); 151 plat->activate_delay_us = fdtdec_get_int(blob, node, 152 "spi-activate-delay", 0); 153 debug("%s: base=%x, max-frequency=%d, deactivate_delay=%d\n", 154 __func__, (uint)plat->base, plat->frequency, 155 plat->deactivate_delay_us); 156 157 return 0; 158 } 159 160 static int rockchip_spi_probe(struct udevice *bus) 161 { 162 struct rockchip_spi_platdata *plat = dev_get_platdata(bus); 163 struct rockchip_spi_priv *priv = dev_get_priv(bus); 164 int ret; 165 166 debug("%s: probe\n", __func__); 167 priv->regs = (struct rockchip_spi *)plat->base; 168 169 priv->last_transaction_us = timer_get_us(); 170 priv->max_freq = plat->frequency; 171 172 /* 173 * Use 99 MHz as our clock since it divides nicely into 594 MHz which 174 * is the assumed speed for CLK_GENERAL. 175 */ 176 ret = clk_set_rate(&priv->clk, 99000000); 177 if (ret < 0) { 178 debug("%s: Failed to set clock: %d\n", __func__, ret); 179 return ret; 180 } 181 priv->input_rate = ret; 182 debug("%s: rate = %u\n", __func__, priv->input_rate); 183 priv->bits_per_word = 8; 184 priv->tmode = TMOD_TR; /* Tx & Rx */ 185 186 return 0; 187 } 188 189 static int rockchip_spi_claim_bus(struct udevice *dev) 190 { 191 struct udevice *bus = dev->parent; 192 struct rockchip_spi_priv *priv = dev_get_priv(bus); 193 struct rockchip_spi *regs = priv->regs; 194 u8 spi_dfs, spi_tf; 195 uint ctrlr0; 196 197 /* Disable the SPI hardware */ 198 rkspi_enable_chip(regs, 0); 199 200 switch (priv->bits_per_word) { 201 case 8: 202 priv->n_bytes = 1; 203 spi_dfs = DFS_8BIT; 204 spi_tf = HALF_WORD_OFF; 205 break; 206 case 16: 207 priv->n_bytes = 2; 208 spi_dfs = DFS_16BIT; 209 spi_tf = HALF_WORD_ON; 210 break; 211 default: 212 debug("%s: unsupported bits: %dbits\n", __func__, 213 priv->bits_per_word); 214 return -EPROTONOSUPPORT; 215 } 216 217 if (priv->speed_hz != priv->last_speed_hz) 218 rkspi_set_clk(priv, priv->speed_hz); 219 220 /* Operation Mode */ 221 ctrlr0 = OMOD_MASTER << OMOD_SHIFT; 222 223 /* Data Frame Size */ 224 ctrlr0 |= spi_dfs << DFS_SHIFT; 225 226 /* set SPI mode 0..3 */ 227 if (priv->mode & SPI_CPOL) 228 ctrlr0 |= SCOL_HIGH << SCOL_SHIFT; 229 if (priv->mode & SPI_CPHA) 230 ctrlr0 |= SCPH_TOGSTA << SCPH_SHIFT; 231 232 /* Chip Select Mode */ 233 ctrlr0 |= CSM_KEEP << CSM_SHIFT; 234 235 /* SSN to Sclk_out delay */ 236 ctrlr0 |= SSN_DELAY_ONE << SSN_DELAY_SHIFT; 237 238 /* Serial Endian Mode */ 239 ctrlr0 |= SEM_LITTLE << SEM_SHIFT; 240 241 /* First Bit Mode */ 242 ctrlr0 |= FBM_MSB << FBM_SHIFT; 243 244 /* Byte and Halfword Transform */ 245 ctrlr0 |= spi_tf << HALF_WORD_TX_SHIFT; 246 247 /* Rxd Sample Delay */ 248 ctrlr0 |= 0 << RXDSD_SHIFT; 249 250 /* Frame Format */ 251 ctrlr0 |= FRF_SPI << FRF_SHIFT; 252 253 /* Tx and Rx mode */ 254 ctrlr0 |= (priv->tmode & TMOD_MASK) << TMOD_SHIFT; 255 256 writel(ctrlr0, ®s->ctrlr0); 257 258 return 0; 259 } 260 261 static int rockchip_spi_release_bus(struct udevice *dev) 262 { 263 struct udevice *bus = dev->parent; 264 struct rockchip_spi_priv *priv = dev_get_priv(bus); 265 266 rkspi_enable_chip(priv->regs, false); 267 268 return 0; 269 } 270 271 static int rockchip_spi_xfer(struct udevice *dev, unsigned int bitlen, 272 const void *dout, void *din, unsigned long flags) 273 { 274 struct udevice *bus = dev->parent; 275 struct rockchip_spi_priv *priv = dev_get_priv(bus); 276 struct rockchip_spi *regs = priv->regs; 277 struct dm_spi_slave_platdata *slave_plat = dev_get_parent_platdata(dev); 278 int len = bitlen >> 3; 279 const u8 *out = dout; 280 u8 *in = din; 281 int toread, towrite; 282 int ret; 283 284 debug("%s: dout=%p, din=%p, len=%x, flags=%lx\n", __func__, dout, din, 285 len, flags); 286 if (DEBUG_RK_SPI) 287 rkspi_dump_regs(regs); 288 289 /* Assert CS before transfer */ 290 if (flags & SPI_XFER_BEGIN) 291 spi_cs_activate(dev, slave_plat->cs); 292 293 while (len > 0) { 294 int todo = min(len, 0xffff); 295 296 rkspi_enable_chip(regs, false); 297 writel(todo - 1, ®s->ctrlr1); 298 rkspi_enable_chip(regs, true); 299 300 toread = todo; 301 towrite = todo; 302 while (toread || towrite) { 303 u32 status = readl(®s->sr); 304 305 if (towrite && !(status & SR_TF_FULL)) { 306 writel(out ? *out++ : 0, regs->txdr); 307 towrite--; 308 } 309 if (toread && !(status & SR_RF_EMPT)) { 310 u32 byte = readl(regs->rxdr); 311 312 if (in) 313 *in++ = byte; 314 toread--; 315 } 316 } 317 ret = rkspi_wait_till_not_busy(regs); 318 if (ret) 319 break; 320 len -= todo; 321 } 322 323 /* Deassert CS after transfer */ 324 if (flags & SPI_XFER_END) 325 spi_cs_deactivate(dev, slave_plat->cs); 326 327 rkspi_enable_chip(regs, false); 328 329 return ret; 330 } 331 332 static int rockchip_spi_set_speed(struct udevice *bus, uint speed) 333 { 334 struct rockchip_spi_priv *priv = dev_get_priv(bus); 335 336 if (speed > ROCKCHIP_SPI_MAX_RATE) 337 return -EINVAL; 338 if (speed > priv->max_freq) 339 speed = priv->max_freq; 340 priv->speed_hz = speed; 341 342 return 0; 343 } 344 345 static int rockchip_spi_set_mode(struct udevice *bus, uint mode) 346 { 347 struct rockchip_spi_priv *priv = dev_get_priv(bus); 348 349 priv->mode = mode; 350 351 return 0; 352 } 353 354 static const struct dm_spi_ops rockchip_spi_ops = { 355 .claim_bus = rockchip_spi_claim_bus, 356 .release_bus = rockchip_spi_release_bus, 357 .xfer = rockchip_spi_xfer, 358 .set_speed = rockchip_spi_set_speed, 359 .set_mode = rockchip_spi_set_mode, 360 /* 361 * cs_info is not needed, since we require all chip selects to be 362 * in the device tree explicitly 363 */ 364 }; 365 366 static const struct udevice_id rockchip_spi_ids[] = { 367 { .compatible = "rockchip,rk3288-spi" }, 368 { } 369 }; 370 371 U_BOOT_DRIVER(rockchip_spi) = { 372 .name = "rockchip_spi", 373 .id = UCLASS_SPI, 374 .of_match = rockchip_spi_ids, 375 .ops = &rockchip_spi_ops, 376 .ofdata_to_platdata = rockchip_spi_ofdata_to_platdata, 377 .platdata_auto_alloc_size = sizeof(struct rockchip_spi_platdata), 378 .priv_auto_alloc_size = sizeof(struct rockchip_spi_priv), 379 .probe = rockchip_spi_probe, 380 }; 381