drivers/spi/cadence_qspi.c

   1 /*
   2  * Copyright (C) 2012
   3  * Altera Corporation <www.altera.com>
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  */
   7
   8 #include <common.h>
   9 #include <dm.h>
  10 #include <fdtdec.h>
  11 #include <malloc.h>
  12 #include <spi.h>
  13 #include <linux/errno.h>
  14 #include "cadence_qspi.h"
  15
  16 #define CQSPI_STIG_READ                 0
  17 #define CQSPI_STIG_WRITE                1
  18 #define CQSPI_INDIRECT_READ             2
  19 #define CQSPI_INDIRECT_WRITE            3
  20
  21 DECLARE_GLOBAL_DATA_PTR;
  22
  23 static int cadence_spi_write_speed(struct udevice *bus, uint hz)
  24 {
  25         struct cadence_spi_platdata *plat = bus->platdata;
  26         struct cadence_spi_priv *priv = dev_get_priv(bus);
  27
  28         cadence_qspi_apb_config_baudrate_div(priv->regbase,
  29                                              CONFIG_CQSPI_REF_CLK, hz);
  30
  31         /* Reconfigure delay timing if speed is changed. */
  32         cadence_qspi_apb_delay(priv->regbase, CONFIG_CQSPI_REF_CLK, hz,
  33                                plat->tshsl_ns, plat->tsd2d_ns,
  34                                plat->tchsh_ns, plat->tslch_ns);
  35
  36         return 0;
  37 }
  38
  39 /* Calibration sequence to determine the read data capture delay register */
  40 static int spi_calibration(struct udevice *bus, uint hz)
  41 {
  42         struct cadence_spi_priv *priv = dev_get_priv(bus);
  43         void *base = priv->regbase;
  44         u8 opcode_rdid = 0x9F;
  45         unsigned int idcode = 0, temp = 0;
  46         int err = 0, i, range_lo = -1, range_hi = -1;
  47
  48         /* start with slowest clock (1 MHz) */
  49         cadence_spi_write_speed(bus, 1000000);
  50
  51         /* configure the read data capture delay register to 0 */
  52         cadence_qspi_apb_readdata_capture(base, 1, 0);
  53
  54         /* Enable QSPI */
  55         cadence_qspi_apb_controller_enable(base);
  56
  57         /* read the ID which will be our golden value */
  58         err = cadence_qspi_apb_command_read(base, 1, &opcode_rdid,
  59                 3, (u8 *)&idcode);
  60         if (err) {
  61                 puts("SF: Calibration failed (read)\n");
  62                 return err;
  63         }
  64
  65         /* use back the intended clock and find low range */
  66         cadence_spi_write_speed(bus, hz);
  67         for (i = 0; i < CQSPI_READ_CAPTURE_MAX_DELAY; i++) {
  68                 /* Disable QSPI */
  69                 cadence_qspi_apb_controller_disable(base);
  70
  71                 /* reconfigure the read data capture delay register */
  72                 cadence_qspi_apb_readdata_capture(base, 1, i);
  73
  74                 /* Enable back QSPI */
  75                 cadence_qspi_apb_controller_enable(base);
  76
  77                 /* issue a RDID to get the ID value */
  78                 err = cadence_qspi_apb_command_read(base, 1, &opcode_rdid,
  79                         3, (u8 *)&temp);
  80                 if (err) {
  81                         puts("SF: Calibration failed (read)\n");
  82                         return err;
  83                 }
  84
  85                 /* search for range lo */
  86                 if (range_lo == -1 && temp == idcode) {
  87                         range_lo = i;
  88                         continue;
  89                 }
  90
  91                 /* search for range hi */
  92                 if (range_lo != -1 && temp != idcode) {
  93                         range_hi = i - 1;
  94                         break;
  95                 }
  96                 range_hi = i;
  97         }
  98
  99         if (range_lo == -1) {
 100                 puts("SF: Calibration failed (low range)\n");
 101                 return err;
 102         }
 103
 104         /* Disable QSPI for subsequent initialization */
 105         cadence_qspi_apb_controller_disable(base);
 106
 107         /* configure the final value for read data capture delay register */
 108         cadence_qspi_apb_readdata_capture(base, 1, (range_hi + range_lo) / 2);
 109         debug("SF: Read data capture delay calibrated to %i (%i - %i)\n",
 110               (range_hi + range_lo) / 2, range_lo, range_hi);
 111
 112         /* just to ensure we do once only when speed or chip select change */
 113         priv->qspi_calibrated_hz = hz;
 114         priv->qspi_calibrated_cs = spi_chip_select(bus);
 115
 116         return 0;
 117 }
 118
 119 static int cadence_spi_set_speed(struct udevice *bus, uint hz)
 120 {
 121         struct cadence_spi_platdata *plat = bus->platdata;
 122         struct cadence_spi_priv *priv = dev_get_priv(bus);
 123         int err;
 124
 125         if (hz > plat->max_hz)
 126                 hz = plat->max_hz;
 127
 128         /* Disable QSPI */
 129         cadence_qspi_apb_controller_disable(priv->regbase);
 130
 131         /*
 132          * Calibration required for different current SCLK speed, requested
 133          * SCLK speed or chip select
 134          */
 135         if (priv->previous_hz != hz ||
 136             priv->qspi_calibrated_hz != hz ||
 137             priv->qspi_calibrated_cs != spi_chip_select(bus)) {
 138                 err = spi_calibration(bus, hz);
 139                 if (err)
 140                         return err;
 141
 142                 /* prevent calibration run when same as previous request */
 143                 priv->previous_hz = hz;
 144         }
 145
 146         /* Enable QSPI */
 147         cadence_qspi_apb_controller_enable(priv->regbase);
 148
 149         debug("%s: speed=%d\n", __func__, hz);
 150
 151         return 0;
 152 }
 153
 154 static int cadence_spi_probe(struct udevice *bus)
 155 {
 156         struct cadence_spi_platdata *plat = bus->platdata;
 157         struct cadence_spi_priv *priv = dev_get_priv(bus);
 158
 159         priv->regbase = plat->regbase;
 160         priv->ahbbase = plat->ahbbase;
 161
 162         if (!priv->qspi_is_init) {
 163                 cadence_qspi_apb_controller_init(plat);
 164                 priv->qspi_is_init = 1;
 165         }
 166
 167         return 0;
 168 }
 169
 170 static int cadence_spi_set_mode(struct udevice *bus, uint mode)
 171 {
 172         struct cadence_spi_priv *priv = dev_get_priv(bus);
 173
 174         /* Disable QSPI */
 175         cadence_qspi_apb_controller_disable(priv->regbase);
 176
 177         /* Set SPI mode */
 178         cadence_qspi_apb_set_clk_mode(priv->regbase, mode);
 179
 180         /* Enable QSPI */
 181         cadence_qspi_apb_controller_enable(priv->regbase);
 182
 183         return 0;
 184 }
 185
 186 static int cadence_spi_xfer(struct udevice *dev, unsigned int bitlen,
 187                             const void *dout, void *din, unsigned long flags)
 188 {
 189         struct udevice *bus = dev->parent;
 190         struct cadence_spi_platdata *plat = bus->platdata;
 191         struct cadence_spi_priv *priv = dev_get_priv(bus);
 192         struct dm_spi_slave_platdata *dm_plat = dev_get_parent_platdata(dev);
 193         void *base = priv->regbase;
 194         u8 *cmd_buf = priv->cmd_buf;
 195         size_t data_bytes;
 196         int err = 0;
 197         u32 mode = CQSPI_STIG_WRITE;
 198
 199         if (flags & SPI_XFER_BEGIN) {
 200                 /* copy command to local buffer */
 201                 priv->cmd_len = bitlen / 8;
 202                 memcpy(cmd_buf, dout, priv->cmd_len);
 203         }
 204
 205         if (flags == (SPI_XFER_BEGIN | SPI_XFER_END)) {
 206                 /* if start and end bit are set, the data bytes is 0. */
 207                 data_bytes = 0;
 208         } else {
 209                 data_bytes = bitlen / 8;
 210         }
 211         debug("%s: len=%d [bytes]\n", __func__, data_bytes);
 212
 213         /* Set Chip select */
 214         cadence_qspi_apb_chipselect(base, spi_chip_select(dev),
 215                                     CONFIG_CQSPI_DECODER);
 216
 217         if ((flags & SPI_XFER_END) || (flags == 0)) {
 218                 if (priv->cmd_len == 0) {
 219                         printf("QSPI: Error, command is empty.\n");
 220                         return -1;
 221                 }
 222
 223                 if (din && data_bytes) {
 224                         /* read */
 225                         /* Use STIG if no address. */
 226                         if (!CQSPI_IS_ADDR(priv->cmd_len))
 227                                 mode = CQSPI_STIG_READ;
 228                         else
 229                                 mode = CQSPI_INDIRECT_READ;
 230                 } else if (dout && !(flags & SPI_XFER_BEGIN)) {
 231                         /* write */
 232                         if (!CQSPI_IS_ADDR(priv->cmd_len))
 233                                 mode = CQSPI_STIG_WRITE;
 234                         else
 235                                 mode = CQSPI_INDIRECT_WRITE;
 236                 }
 237
 238                 switch (mode) {
 239                 case CQSPI_STIG_READ:
 240                         err = cadence_qspi_apb_command_read(
 241                                 base, priv->cmd_len, cmd_buf,
 242                                 data_bytes, din);
 243
 244                 break;
 245                 case CQSPI_STIG_WRITE:
 246                         err = cadence_qspi_apb_command_write(base,
 247                                 priv->cmd_len, cmd_buf,
 248                                 data_bytes, dout);
 249                 break;
 250                 case CQSPI_INDIRECT_READ:
 251                         err = cadence_qspi_apb_indirect_read_setup(plat,
 252                                 priv->cmd_len, dm_plat->mode, cmd_buf);
 253                         if (!err) {
 254                                 err = cadence_qspi_apb_indirect_read_execute
 255                                 (plat, data_bytes, din);
 256                         }
 257                 break;
 258                 case CQSPI_INDIRECT_WRITE:
 259                         err = cadence_qspi_apb_indirect_write_setup
 260                                 (plat, priv->cmd_len, cmd_buf);
 261                         if (!err) {
 262                                 err = cadence_qspi_apb_indirect_write_execute
 263                                 (plat, data_bytes, dout);
 264                         }
 265                 break;
 266                 default:
 267                         err = -1;
 268                         break;
 269                 }
 270
 271                 if (flags & SPI_XFER_END) {
 272                         /* clear command buffer */
 273                         memset(cmd_buf, 0, sizeof(priv->cmd_buf));
 274                         priv->cmd_len = 0;
 275                 }
 276         }
 277
 278         return err;
 279 }
 280
 281 static int cadence_spi_ofdata_to_platdata(struct udevice *bus)
 282 {
 283         struct cadence_spi_platdata *plat = bus->platdata;
 284         const void *blob = gd->fdt_blob;
 285         int node = dev_of_offset(bus);
 286         int subnode;
 287         u32 data[4];
 288         int ret;
 289
 290         /* 2 base addresses are needed, lets get them from the DT */
 291         ret = fdtdec_get_int_array(blob, node, "reg", data, ARRAY_SIZE(data));
 292         if (ret) {
 293                 printf("Error: Can't get base addresses (ret=%d)!\n", ret);
 294                 return -ENODEV;
 295         }
 296
 297         plat->regbase = (void *)data[0];
 298         plat->ahbbase = (void *)data[2];
 299         plat->sram_size = fdtdec_get_int(blob, node, "sram-size", 128);
 300
 301         /* All other paramters are embedded in the child node */
 302         subnode = fdt_first_subnode(blob, node);
 303         if (subnode < 0) {
 304                 printf("Error: subnode with SPI flash config missing!\n");
 305                 return -ENODEV;
 306         }
 307
 308         /* Use 500 KHz as a suitable default */
 309         plat->max_hz = fdtdec_get_uint(blob, subnode, "spi-max-frequency",
 310                                        500000);
 311
 312         /* Read other parameters from DT */
 313         plat->page_size = fdtdec_get_int(blob, subnode, "page-size", 256);
 314         plat->block_size = fdtdec_get_int(blob, subnode, "block-size", 16);
 315         plat->tshsl_ns = fdtdec_get_int(blob, subnode, "tshsl-ns", 200);
 316         plat->tsd2d_ns = fdtdec_get_int(blob, subnode, "tsd2d-ns", 255);
 317         plat->tchsh_ns = fdtdec_get_int(blob, subnode, "tchsh-ns", 20);
 318         plat->tslch_ns = fdtdec_get_int(blob, subnode, "tslch-ns", 20);
 319
 320         debug("%s: regbase=%p ahbbase=%p max-frequency=%d page-size=%d\n",
 321               __func__, plat->regbase, plat->ahbbase, plat->max_hz,
 322               plat->page_size);
 323
 324         return 0;
 325 }
 326
 327 static const struct dm_spi_ops cadence_spi_ops = {
 328         .xfer           = cadence_spi_xfer,
 329         .set_speed      = cadence_spi_set_speed,
 330         .set_mode       = cadence_spi_set_mode,
 331         /*
 332          * cs_info is not needed, since we require all chip selects to be
 333          * in the device tree explicitly
 334          */
 335 };
 336
 337 static const struct udevice_id cadence_spi_ids[] = {
 338         { .compatible = "cadence,qspi" },
 339         { }
 340 };
 341
 342 U_BOOT_DRIVER(cadence_spi) = {
 343         .name = "cadence_spi",
 344         .id = UCLASS_SPI,
 345         .of_match = cadence_spi_ids,
 346         .ops = &cadence_spi_ops,
 347         .ofdata_to_platdata = cadence_spi_ofdata_to_platdata,
 348         .platdata_auto_alloc_size = sizeof(struct cadence_spi_platdata),
 349         .priv_auto_alloc_size = sizeof(struct cadence_spi_priv),
 350         .probe = cadence_spi_probe,
 351 };