drivers/misc/lattice-ecp3-config.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright (C) 2012 Stefan Roese <sr@denx.de>
   4  */
   5
   6 #include <linux/device.h>
   7 #include <linux/firmware.h>
   8 #include <linux/module.h>
   9 #include <linux/errno.h>
  10 #include <linux/kernel.h>
  11 #include <linux/spi/spi.h>
  12 #include <linux/platform_device.h>
  13 #include <linux/delay.h>
  14 #include <asm/unaligned.h>
  15
  16 #define FIRMWARE_NAME   "lattice-ecp3.bit"
  17
  18 /*
  19  * The JTAG ID's of the supported FPGA's. The ID is 32bit wide
  20  * reversed as noted in the manual.
  21  */
  22 #define ID_ECP3_17      0xc2088080
  23 #define ID_ECP3_35      0xc2048080
  24
  25 /* FPGA commands */
  26 #define FPGA_CMD_READ_ID        0x07    /* plus 24 bits */
  27 #define FPGA_CMD_READ_STATUS    0x09    /* plus 24 bits */
  28 #define FPGA_CMD_CLEAR          0x70
  29 #define FPGA_CMD_REFRESH        0x71
  30 #define FPGA_CMD_WRITE_EN       0x4a    /* plus 2 bits */
  31 #define FPGA_CMD_WRITE_DIS      0x4f    /* plus 8 bits */
  32 #define FPGA_CMD_WRITE_INC      0x41    /* plus 0 bits */
  33
  34 /*
  35  * The status register is 32bit revered, DONE is bit 17 from the TN1222.pdf
  36  * (LatticeECP3 Slave SPI Port User's Guide)
  37  */
  38 #define FPGA_STATUS_DONE        0x00004000
  39 #define FPGA_STATUS_CLEARED     0x00010000
  40
  41 #define FPGA_CLEAR_TIMEOUT      5000    /* max. 5000ms for FPGA clear */
  42 #define FPGA_CLEAR_MSLEEP       10
  43 #define FPGA_CLEAR_LOOP_COUNT   (FPGA_CLEAR_TIMEOUT / FPGA_CLEAR_MSLEEP)
  44
  45 struct fpga_data {
  46         struct completion fw_loaded;
  47 };
  48
  49 struct ecp3_dev {
  50         u32 jedec_id;
  51         char *name;
  52 };
  53
  54 static const struct ecp3_dev ecp3_dev[] = {
  55         {
  56                 .jedec_id = ID_ECP3_17,
  57                 .name = "Lattice ECP3-17",
  58         },
  59         {
  60                 .jedec_id = ID_ECP3_35,
  61                 .name = "Lattice ECP3-35",
  62         },
  63 };
  64
  65 static void firmware_load(const struct firmware *fw, void *context)
  66 {
  67         struct spi_device *spi = (struct spi_device *)context;
  68         struct fpga_data *data = spi_get_drvdata(spi);
  69         u8 *buffer;
  70         u8 txbuf[8];
  71         u8 rxbuf[8];
  72         int rx_len = 8;
  73         int i;
  74         u32 jedec_id;
  75         u32 status;
  76
  77         if (fw == NULL) {
  78                 dev_err(&spi->dev, "Cannot load firmware, aborting\n");
  79                 goto out;
  80         }
  81
  82         if (fw->size == 0) {
  83                 dev_err(&spi->dev, "Error: Firmware size is 0!\n");
  84                 goto out;
  85         }
  86
  87         /* Fill dummy data (24 stuffing bits for commands) */
  88         txbuf[1] = 0x00;
  89         txbuf[2] = 0x00;
  90         txbuf[3] = 0x00;
  91
  92         /* Trying to speak with the FPGA via SPI... */
  93         txbuf[0] = FPGA_CMD_READ_ID;
  94         spi_write_then_read(spi, txbuf, 8, rxbuf, rx_len);
  95         jedec_id = get_unaligned_be32(&rxbuf[4]);
  96         dev_dbg(&spi->dev, "FPGA JTAG ID=%08x\n", jedec_id);
  97
  98         for (i = 0; i < ARRAY_SIZE(ecp3_dev); i++) {
  99                 if (jedec_id == ecp3_dev[i].jedec_id)
 100                         break;
 101         }
 102         if (i == ARRAY_SIZE(ecp3_dev)) {
 103                 dev_err(&spi->dev,
 104                         "Error: No supported FPGA detected (JEDEC_ID=%08x)!\n",
 105                         jedec_id);
 106                 goto out;
 107         }
 108
 109         dev_info(&spi->dev, "FPGA %s detected\n", ecp3_dev[i].name);
 110
 111         txbuf[0] = FPGA_CMD_READ_STATUS;
 112         spi_write_then_read(spi, txbuf, 8, rxbuf, rx_len);
 113         status = get_unaligned_be32(&rxbuf[4]);
 114         dev_dbg(&spi->dev, "FPGA Status=%08x\n", status);
 115
 116         buffer = kzalloc(fw->size + 8, GFP_KERNEL);
 117         if (!buffer) {
 118                 dev_err(&spi->dev, "Error: Can't allocate memory!\n");
 119                 goto out;
 120         }
 121
 122         /*
 123          * Insert WRITE_INC command into stream (one SPI frame)
 124          */
 125         buffer[0] = FPGA_CMD_WRITE_INC;
 126         buffer[1] = 0xff;
 127         buffer[2] = 0xff;
 128         buffer[3] = 0xff;
 129         memcpy(buffer + 4, fw->data, fw->size);
 130
 131         txbuf[0] = FPGA_CMD_REFRESH;
 132         spi_write(spi, txbuf, 4);
 133
 134         txbuf[0] = FPGA_CMD_WRITE_EN;
 135         spi_write(spi, txbuf, 4);
 136
 137         txbuf[0] = FPGA_CMD_CLEAR;
 138         spi_write(spi, txbuf, 4);
 139
 140         /*
 141          * Wait for FPGA memory to become cleared
 142          */
 143         for (i = 0; i < FPGA_CLEAR_LOOP_COUNT; i++) {
 144                 txbuf[0] = FPGA_CMD_READ_STATUS;
 145                 spi_write_then_read(spi, txbuf, 8, rxbuf, rx_len);
 146                 status = get_unaligned_be32(&rxbuf[4]);
 147                 if (status == FPGA_STATUS_CLEARED)
 148                         break;
 149
 150                 msleep(FPGA_CLEAR_MSLEEP);
 151         }
 152
 153         if (i == FPGA_CLEAR_LOOP_COUNT) {
 154                 dev_err(&spi->dev,
 155                         "Error: Timeout waiting for FPGA to clear (status=%08x)!\n",
 156                         status);
 157                 kfree(buffer);
 158                 goto out;
 159         }
 160
 161         dev_info(&spi->dev, "Configuring the FPGA...\n");
 162         spi_write(spi, buffer, fw->size + 8);
 163
 164         txbuf[0] = FPGA_CMD_WRITE_DIS;
 165         spi_write(spi, txbuf, 4);
 166
 167         txbuf[0] = FPGA_CMD_READ_STATUS;
 168         spi_write_then_read(spi, txbuf, 8, rxbuf, rx_len);
 169         status = get_unaligned_be32(&rxbuf[4]);
 170         dev_dbg(&spi->dev, "FPGA Status=%08x\n", status);
 171
 172         /* Check result */
 173         if (status & FPGA_STATUS_DONE)
 174                 dev_info(&spi->dev, "FPGA successfully configured!\n");
 175         else
 176                 dev_info(&spi->dev, "FPGA not configured (DONE not set)\n");
 177
 178         /*
 179          * Don't forget to release the firmware again
 180          */
 181         release_firmware(fw);
 182
 183         kfree(buffer);
 184 out:
 185         complete(&data->fw_loaded);
 186 }
 187
 188 static int lattice_ecp3_probe(struct spi_device *spi)
 189 {
 190         struct fpga_data *data;
 191         int err;
 192
 193         data = devm_kzalloc(&spi->dev, sizeof(*data), GFP_KERNEL);
 194         if (!data) {
 195                 dev_err(&spi->dev, "Memory allocation for fpga_data failed\n");
 196                 return -ENOMEM;
 197         }
 198         spi_set_drvdata(spi, data);
 199
 200         init_completion(&data->fw_loaded);
 201         err = request_firmware_nowait(THIS_MODULE, FW_ACTION_UEVENT,
 202                                       FIRMWARE_NAME, &spi->dev,
 203                                       GFP_KERNEL, spi, firmware_load);
 204         if (err) {
 205                 dev_err(&spi->dev, "Firmware loading failed with %d!\n", err);
 206                 return err;
 207         }
 208
 209         dev_info(&spi->dev, "FPGA bitstream configuration driver registered\n");
 210
 211         return 0;
 212 }
 213
 214 static void lattice_ecp3_remove(struct spi_device *spi)
 215 {
 216         struct fpga_data *data = spi_get_drvdata(spi);
 217
 218         wait_for_completion(&data->fw_loaded);
 219 }
 220
 221 static const struct spi_device_id lattice_ecp3_id[] = {
 222         { "ecp3-17", 0 },
 223         { "ecp3-35", 0 },
 224         { }
 225 };
 226 MODULE_DEVICE_TABLE(spi, lattice_ecp3_id);
 227
 228 static struct spi_driver lattice_ecp3_driver = {
 229         .driver = {
 230                 .name = "lattice-ecp3",
 231         },
 232         .probe = lattice_ecp3_probe,
 233         .remove = lattice_ecp3_remove,
 234         .id_table = lattice_ecp3_id,
 235 };
 236
 237 module_spi_driver(lattice_ecp3_driver);
 238
 239 MODULE_AUTHOR("Stefan Roese <sr@denx.de>");
 240 MODULE_DESCRIPTION("Lattice ECP3 FPGA configuration via SPI");
 241 MODULE_LICENSE("GPL");
 242 MODULE_FIRMWARE(FIRMWARE_NAME);