1 /* 2 * NVIDIA Tegra SPI-SLINK controller 3 * 4 * Copyright (c) 2010-2013 NVIDIA Corporation 5 * 6 * SPDX-License-Identifier: GPL-2.0 7 */ 8 9 #include <common.h> 10 #include <dm.h> 11 #include <asm/io.h> 12 #include <asm/arch/clock.h> 13 #include <asm/arch-tegra/clk_rst.h> 14 #include <spi.h> 15 #include <fdtdec.h> 16 #include "tegra_spi.h" 17 18 DECLARE_GLOBAL_DATA_PTR; 19 20 /* COMMAND */ 21 #define SLINK_CMD_ENB BIT(31) 22 #define SLINK_CMD_GO BIT(30) 23 #define SLINK_CMD_M_S BIT(28) 24 #define SLINK_CMD_IDLE_SCLK_DRIVE_LOW (0 << 24) 25 #define SLINK_CMD_IDLE_SCLK_DRIVE_HIGH BIT(24) 26 #define SLINK_CMD_IDLE_SCLK_PULL_LOW (2 << 24) 27 #define SLINK_CMD_IDLE_SCLK_PULL_HIGH (3 << 24) 28 #define SLINK_CMD_IDLE_SCLK_MASK (3 << 24) 29 #define SLINK_CMD_CK_SDA BIT(21) 30 #define SLINK_CMD_CS_POL BIT(13) 31 #define SLINK_CMD_CS_VAL BIT(12) 32 #define SLINK_CMD_CS_SOFT BIT(11) 33 #define SLINK_CMD_BIT_LENGTH BIT(4) 34 #define SLINK_CMD_BIT_LENGTH_MASK GENMASK(4, 0) 35 /* COMMAND2 */ 36 #define SLINK_CMD2_TXEN BIT(30) 37 #define SLINK_CMD2_RXEN BIT(31) 38 #define SLINK_CMD2_SS_EN BIT(18) 39 #define SLINK_CMD2_SS_EN_SHIFT 18 40 #define SLINK_CMD2_SS_EN_MASK GENMASK(19, 18) 41 #define SLINK_CMD2_CS_ACTIVE_BETWEEN BIT(17) 42 /* STATUS */ 43 #define SLINK_STAT_BSY BIT(31) 44 #define SLINK_STAT_RDY BIT(30) 45 #define SLINK_STAT_ERR BIT(29) 46 #define SLINK_STAT_RXF_FLUSH BIT(27) 47 #define SLINK_STAT_TXF_FLUSH BIT(26) 48 #define SLINK_STAT_RXF_OVF BIT(25) 49 #define SLINK_STAT_TXF_UNR BIT(24) 50 #define SLINK_STAT_RXF_EMPTY BIT(23) 51 #define SLINK_STAT_RXF_FULL BIT(22) 52 #define SLINK_STAT_TXF_EMPTY BIT(21) 53 #define SLINK_STAT_TXF_FULL BIT(20) 54 #define SLINK_STAT_TXF_OVF BIT(19) 55 #define SLINK_STAT_RXF_UNR BIT(18) 56 #define SLINK_STAT_CUR_BLKCNT BIT(15) 57 /* STATUS2 */ 58 #define SLINK_STAT2_RXF_FULL_CNT BIT(16) 59 #define SLINK_STAT2_TXF_FULL_CNT BIT(0) 60 61 #define SPI_TIMEOUT 1000 62 #define TEGRA_SPI_MAX_FREQ 52000000 63 64 struct spi_regs { 65 u32 command; /* SLINK_COMMAND_0 register */ 66 u32 command2; /* SLINK_COMMAND2_0 reg */ 67 u32 status; /* SLINK_STATUS_0 register */ 68 u32 reserved; /* Reserved offset 0C */ 69 u32 mas_data; /* SLINK_MAS_DATA_0 reg */ 70 u32 slav_data; /* SLINK_SLAVE_DATA_0 reg */ 71 u32 dma_ctl; /* SLINK_DMA_CTL_0 register */ 72 u32 status2; /* SLINK_STATUS2_0 reg */ 73 u32 rsvd[56]; /* 0x20 to 0xFF reserved */ 74 u32 tx_fifo; /* SLINK_TX_FIFO_0 reg off 100h */ 75 u32 rsvd2[31]; /* 0x104 to 0x17F reserved */ 76 u32 rx_fifo; /* SLINK_RX_FIFO_0 reg off 180h */ 77 }; 78 79 struct tegra30_spi_priv { 80 struct spi_regs *regs; 81 unsigned int freq; 82 unsigned int mode; 83 int periph_id; 84 int valid; 85 int last_transaction_us; 86 }; 87 88 struct tegra_spi_slave { 89 struct spi_slave slave; 90 struct tegra30_spi_priv *ctrl; 91 }; 92 93 static int tegra30_spi_ofdata_to_platdata(struct udevice *bus) 94 { 95 struct tegra_spi_platdata *plat = bus->platdata; 96 const void *blob = gd->fdt_blob; 97 int node = dev_of_offset(bus); 98 99 plat->base = devfdt_get_addr(bus); 100 plat->periph_id = clock_decode_periph_id(bus); 101 102 if (plat->periph_id == PERIPH_ID_NONE) { 103 debug("%s: could not decode periph id %d\n", __func__, 104 plat->periph_id); 105 return -FDT_ERR_NOTFOUND; 106 } 107 108 /* Use 500KHz as a suitable default */ 109 plat->frequency = fdtdec_get_int(blob, node, "spi-max-frequency", 110 500000); 111 plat->deactivate_delay_us = fdtdec_get_int(blob, node, 112 "spi-deactivate-delay", 0); 113 debug("%s: base=%#08lx, periph_id=%d, max-frequency=%d, deactivate_delay=%d\n", 114 __func__, plat->base, plat->periph_id, plat->frequency, 115 plat->deactivate_delay_us); 116 117 return 0; 118 } 119 120 static int tegra30_spi_probe(struct udevice *bus) 121 { 122 struct tegra_spi_platdata *plat = dev_get_platdata(bus); 123 struct tegra30_spi_priv *priv = dev_get_priv(bus); 124 125 priv->regs = (struct spi_regs *)plat->base; 126 127 priv->last_transaction_us = timer_get_us(); 128 priv->freq = plat->frequency; 129 priv->periph_id = plat->periph_id; 130 131 /* Change SPI clock to correct frequency, PLLP_OUT0 source */ 132 clock_start_periph_pll(priv->periph_id, CLOCK_ID_PERIPH, 133 priv->freq); 134 135 return 0; 136 } 137 138 static int tegra30_spi_claim_bus(struct udevice *dev) 139 { 140 struct udevice *bus = dev->parent; 141 struct tegra30_spi_priv *priv = dev_get_priv(bus); 142 struct spi_regs *regs = priv->regs; 143 u32 reg; 144 145 /* Change SPI clock to correct frequency, PLLP_OUT0 source */ 146 clock_start_periph_pll(priv->periph_id, CLOCK_ID_PERIPH, 147 priv->freq); 148 149 /* Clear stale status here */ 150 reg = SLINK_STAT_RDY | SLINK_STAT_RXF_FLUSH | SLINK_STAT_TXF_FLUSH | \ 151 SLINK_STAT_RXF_UNR | SLINK_STAT_TXF_OVF; 152 writel(reg, ®s->status); 153 debug("%s: STATUS = %08x\n", __func__, readl(®s->status)); 154 155 /* Set master mode and sw controlled CS */ 156 reg = readl(®s->command); 157 reg |= SLINK_CMD_M_S | SLINK_CMD_CS_SOFT; 158 writel(reg, ®s->command); 159 debug("%s: COMMAND = %08x\n", __func__, readl(®s->command)); 160 161 return 0; 162 } 163 164 static void spi_cs_activate(struct udevice *dev) 165 { 166 struct udevice *bus = dev->parent; 167 struct tegra_spi_platdata *pdata = dev_get_platdata(bus); 168 struct tegra30_spi_priv *priv = dev_get_priv(bus); 169 170 /* If it's too soon to do another transaction, wait */ 171 if (pdata->deactivate_delay_us && 172 priv->last_transaction_us) { 173 ulong delay_us; /* The delay completed so far */ 174 delay_us = timer_get_us() - priv->last_transaction_us; 175 if (delay_us < pdata->deactivate_delay_us) 176 udelay(pdata->deactivate_delay_us - delay_us); 177 } 178 179 /* CS is negated on Tegra, so drive a 1 to get a 0 */ 180 setbits_le32(&priv->regs->command, SLINK_CMD_CS_VAL); 181 } 182 183 static void spi_cs_deactivate(struct udevice *dev) 184 { 185 struct udevice *bus = dev->parent; 186 struct tegra_spi_platdata *pdata = dev_get_platdata(bus); 187 struct tegra30_spi_priv *priv = dev_get_priv(bus); 188 189 /* CS is negated on Tegra, so drive a 0 to get a 1 */ 190 clrbits_le32(&priv->regs->command, SLINK_CMD_CS_VAL); 191 192 /* Remember time of this transaction so we can honour the bus delay */ 193 if (pdata->deactivate_delay_us) 194 priv->last_transaction_us = timer_get_us(); 195 } 196 197 static int tegra30_spi_xfer(struct udevice *dev, unsigned int bitlen, 198 const void *data_out, void *data_in, 199 unsigned long flags) 200 { 201 struct udevice *bus = dev->parent; 202 struct tegra30_spi_priv *priv = dev_get_priv(bus); 203 struct spi_regs *regs = priv->regs; 204 u32 reg, tmpdout, tmpdin = 0; 205 const u8 *dout = data_out; 206 u8 *din = data_in; 207 int num_bytes; 208 int ret; 209 210 debug("%s: slave %u:%u dout %p din %p bitlen %u\n", 211 __func__, bus->seq, spi_chip_select(dev), dout, din, bitlen); 212 if (bitlen % 8) 213 return -1; 214 num_bytes = bitlen / 8; 215 216 ret = 0; 217 218 reg = readl(®s->status); 219 writel(reg, ®s->status); /* Clear all SPI events via R/W */ 220 debug("%s entry: STATUS = %08x\n", __func__, reg); 221 222 reg = readl(®s->status2); 223 writel(reg, ®s->status2); /* Clear all STATUS2 events via R/W */ 224 debug("%s entry: STATUS2 = %08x\n", __func__, reg); 225 226 debug("%s entry: COMMAND = %08x\n", __func__, readl(®s->command)); 227 228 clrsetbits_le32(®s->command2, SLINK_CMD2_SS_EN_MASK, 229 SLINK_CMD2_TXEN | SLINK_CMD2_RXEN | 230 (spi_chip_select(dev) << SLINK_CMD2_SS_EN_SHIFT)); 231 debug("%s entry: COMMAND2 = %08x\n", __func__, readl(®s->command2)); 232 233 if (flags & SPI_XFER_BEGIN) 234 spi_cs_activate(dev); 235 236 /* handle data in 32-bit chunks */ 237 while (num_bytes > 0) { 238 int bytes; 239 int is_read = 0; 240 int tm, i; 241 242 tmpdout = 0; 243 bytes = (num_bytes > 4) ? 4 : num_bytes; 244 245 if (dout != NULL) { 246 for (i = 0; i < bytes; ++i) 247 tmpdout = (tmpdout << 8) | dout[i]; 248 dout += bytes; 249 } 250 251 num_bytes -= bytes; 252 253 clrsetbits_le32(®s->command, SLINK_CMD_BIT_LENGTH_MASK, 254 bytes * 8 - 1); 255 writel(tmpdout, ®s->tx_fifo); 256 setbits_le32(®s->command, SLINK_CMD_GO); 257 258 /* 259 * Wait for SPI transmit FIFO to empty, or to time out. 260 * The RX FIFO status will be read and cleared last 261 */ 262 for (tm = 0, is_read = 0; tm < SPI_TIMEOUT; ++tm) { 263 u32 status; 264 265 status = readl(®s->status); 266 267 /* We can exit when we've had both RX and TX activity */ 268 if (is_read && (status & SLINK_STAT_TXF_EMPTY)) 269 break; 270 271 if ((status & (SLINK_STAT_BSY | SLINK_STAT_RDY)) != 272 SLINK_STAT_RDY) 273 tm++; 274 275 else if (!(status & SLINK_STAT_RXF_EMPTY)) { 276 tmpdin = readl(®s->rx_fifo); 277 is_read = 1; 278 279 /* swap bytes read in */ 280 if (din != NULL) { 281 for (i = bytes - 1; i >= 0; --i) { 282 din[i] = tmpdin & 0xff; 283 tmpdin >>= 8; 284 } 285 din += bytes; 286 } 287 } 288 } 289 290 if (tm >= SPI_TIMEOUT) 291 ret = tm; 292 293 /* clear ACK RDY, etc. bits */ 294 writel(readl(®s->status), ®s->status); 295 } 296 297 if (flags & SPI_XFER_END) 298 spi_cs_deactivate(dev); 299 300 debug("%s: transfer ended. Value=%08x, status = %08x\n", 301 __func__, tmpdin, readl(®s->status)); 302 303 if (ret) { 304 printf("%s: timeout during SPI transfer, tm %d\n", 305 __func__, ret); 306 return -1; 307 } 308 309 return 0; 310 } 311 312 static int tegra30_spi_set_speed(struct udevice *bus, uint speed) 313 { 314 struct tegra_spi_platdata *plat = bus->platdata; 315 struct tegra30_spi_priv *priv = dev_get_priv(bus); 316 317 if (speed > plat->frequency) 318 speed = plat->frequency; 319 priv->freq = speed; 320 debug("%s: regs=%p, speed=%d\n", __func__, priv->regs, priv->freq); 321 322 return 0; 323 } 324 325 static int tegra30_spi_set_mode(struct udevice *bus, uint mode) 326 { 327 struct tegra30_spi_priv *priv = dev_get_priv(bus); 328 struct spi_regs *regs = priv->regs; 329 u32 reg; 330 331 reg = readl(®s->command); 332 333 /* Set CPOL and CPHA */ 334 reg &= ~(SLINK_CMD_IDLE_SCLK_MASK | SLINK_CMD_CK_SDA); 335 if (mode & SPI_CPHA) 336 reg |= SLINK_CMD_CK_SDA; 337 338 if (mode & SPI_CPOL) 339 reg |= SLINK_CMD_IDLE_SCLK_DRIVE_HIGH; 340 else 341 reg |= SLINK_CMD_IDLE_SCLK_DRIVE_LOW; 342 343 writel(reg, ®s->command); 344 345 priv->mode = mode; 346 debug("%s: regs=%p, mode=%d\n", __func__, priv->regs, priv->mode); 347 348 return 0; 349 } 350 351 static const struct dm_spi_ops tegra30_spi_ops = { 352 .claim_bus = tegra30_spi_claim_bus, 353 .xfer = tegra30_spi_xfer, 354 .set_speed = tegra30_spi_set_speed, 355 .set_mode = tegra30_spi_set_mode, 356 /* 357 * cs_info is not needed, since we require all chip selects to be 358 * in the device tree explicitly 359 */ 360 }; 361 362 static const struct udevice_id tegra30_spi_ids[] = { 363 { .compatible = "nvidia,tegra20-slink" }, 364 { } 365 }; 366 367 U_BOOT_DRIVER(tegra30_spi) = { 368 .name = "tegra20_slink", 369 .id = UCLASS_SPI, 370 .of_match = tegra30_spi_ids, 371 .ops = &tegra30_spi_ops, 372 .ofdata_to_platdata = tegra30_spi_ofdata_to_platdata, 373 .platdata_auto_alloc_size = sizeof(struct tegra_spi_platdata), 374 .priv_auto_alloc_size = sizeof(struct tegra30_spi_priv), 375 .probe = tegra30_spi_probe, 376 }; 377