drivers/misc/lattice-ecp3-config.c

   1 /*
   2  * Copyright (C) 2012 Stefan Roese <sr@denx.de>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  */
   9
  10 #include <linux/device.h>
  11 #include <linux/firmware.h>
  12 #include <linux/module.h>
  13 #include <linux/errno.h>
  14 #include <linux/kernel.h>
  15 #include <linux/init.h>
  16 #include <linux/spi/spi.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/delay.h>
  19
  20 #define FIRMWARE_NAME   "lattice-ecp3.bit"
  21
  22 /*
  23  * The JTAG ID's of the supported FPGA's. The ID is 32bit wide
  24  * reversed as noted in the manual.
  25  */
  26 #define ID_ECP3_17      0xc2088080
  27 #define ID_ECP3_35      0xc2048080
  28
  29 /* FPGA commands */
  30 #define FPGA_CMD_READ_ID        0x07    /* plus 24 bits */
  31 #define FPGA_CMD_READ_STATUS    0x09    /* plus 24 bits */
  32 #define FPGA_CMD_CLEAR          0x70
  33 #define FPGA_CMD_REFRESH        0x71
  34 #define FPGA_CMD_WRITE_EN       0x4a    /* plus 2 bits */
  35 #define FPGA_CMD_WRITE_DIS      0x4f    /* plus 8 bits */
  36 #define FPGA_CMD_WRITE_INC      0x41    /* plus 0 bits */
  37
  38 /*
  39  * The status register is 32bit revered, DONE is bit 17 from the TN1222.pdf
  40  * (LatticeECP3 Slave SPI Port User's Guide)
  41  */
  42 #define FPGA_STATUS_DONE        0x00004000
  43 #define FPGA_STATUS_CLEARED     0x00010000
  44
  45 #define FPGA_CLEAR_TIMEOUT      5000    /* max. 5000ms for FPGA clear */
  46 #define FPGA_CLEAR_MSLEEP       10
  47 #define FPGA_CLEAR_LOOP_COUNT   (FPGA_CLEAR_TIMEOUT / FPGA_CLEAR_MSLEEP)
  48
  49 struct fpga_data {
  50         struct completion fw_loaded;
  51 };
  52
  53 struct ecp3_dev {
  54         u32 jedec_id;
  55         char *name;
  56 };
  57
  58 static const struct ecp3_dev ecp3_dev[] = {
  59         {
  60                 .jedec_id = ID_ECP3_17,
  61                 .name = "Lattice ECP3-17",
  62         },
  63         {
  64                 .jedec_id = ID_ECP3_35,
  65                 .name = "Lattice ECP3-35",
  66         },
  67 };
  68
  69 static void firmware_load(const struct firmware *fw, void *context)
  70 {
  71         struct spi_device *spi = (struct spi_device *)context;
  72         struct fpga_data *data = spi_get_drvdata(spi);
  73         u8 *buffer;
  74         int ret;
  75         u8 txbuf[8];
  76         u8 rxbuf[8];
  77         int rx_len = 8;
  78         int i;
  79         u32 jedec_id;
  80         u32 status;
  81
  82         if (fw->size == 0) {
  83                 dev_err(&spi->dev, "Error: Firmware size is 0!\n");
  84                 return;
  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         ret = spi_write_then_read(spi, txbuf, 8, rxbuf, rx_len);
  95         dev_dbg(&spi->dev, "FPGA JTAG ID=%08x\n", *(u32 *)&rxbuf[4]);
  96         jedec_id = *(u32 *)&rxbuf[4];
  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                 return;
 107         }
 108
 109         dev_info(&spi->dev, "FPGA %s detected\n", ecp3_dev[i].name);
 110
 111         txbuf[0] = FPGA_CMD_READ_STATUS;
 112         ret = spi_write_then_read(spi, txbuf, 8, rxbuf, rx_len);
 113         dev_dbg(&spi->dev, "FPGA Status=%08x\n", *(u32 *)&rxbuf[4]);
 114
 115         buffer = kzalloc(fw->size + 8, GFP_KERNEL);
 116         if (!buffer) {
 117                 dev_err(&spi->dev, "Error: Can't allocate memory!\n");
 118                 return;
 119         }
 120
 121         /*
 122          * Insert WRITE_INC command into stream (one SPI frame)
 123          */
 124         buffer[0] = FPGA_CMD_WRITE_INC;
 125         buffer[1] = 0xff;
 126         buffer[2] = 0xff;
 127         buffer[3] = 0xff;
 128         memcpy(buffer + 4, fw->data, fw->size);
 129
 130         txbuf[0] = FPGA_CMD_REFRESH;
 131         ret = spi_write(spi, txbuf, 4);
 132
 133         txbuf[0] = FPGA_CMD_WRITE_EN;
 134         ret = spi_write(spi, txbuf, 4);
 135
 136         txbuf[0] = FPGA_CMD_CLEAR;
 137         ret = spi_write(spi, txbuf, 4);
 138
 139         /*
 140          * Wait for FPGA memory to become cleared
 141          */
 142         for (i = 0; i < FPGA_CLEAR_LOOP_COUNT; i++) {
 143                 txbuf[0] = FPGA_CMD_READ_STATUS;
 144                 ret = spi_write_then_read(spi, txbuf, 8, rxbuf, rx_len);
 145                 status = *(u32 *)&rxbuf[4];
 146                 if (status == FPGA_STATUS_CLEARED)
 147                         break;
 148
 149                 msleep(FPGA_CLEAR_MSLEEP);
 150         }
 151
 152         if (i == FPGA_CLEAR_LOOP_COUNT) {
 153                 dev_err(&spi->dev,
 154                         "Error: Timeout waiting for FPGA to clear (status=%08x)!\n",
 155                         status);
 156                 kfree(buffer);
 157                 return;
 158         }
 159
 160         dev_info(&spi->dev, "Configuring the FPGA...\n");
 161         ret = spi_write(spi, buffer, fw->size + 8);
 162
 163         txbuf[0] = FPGA_CMD_WRITE_DIS;
 164         ret = spi_write(spi, txbuf, 4);
 165
 166         txbuf[0] = FPGA_CMD_READ_STATUS;
 167         ret = spi_write_then_read(spi, txbuf, 8, rxbuf, rx_len);
 168         dev_dbg(&spi->dev, "FPGA Status=%08x\n", *(u32 *)&rxbuf[4]);
 169         status = *(u32 *)&rxbuf[4];
 170
 171         /* Check result */
 172         if (status & FPGA_STATUS_DONE)
 173                 dev_info(&spi->dev, "FPGA successfully configured!\n");
 174         else
 175                 dev_info(&spi->dev, "FPGA not configured (DONE not set)\n");
 176
 177         /*
 178          * Don't forget to release the firmware again
 179          */
 180         release_firmware(fw);
 181
 182         kfree(buffer);
 183
 184         complete(&data->fw_loaded);
 185 }
 186
 187 static int lattice_ecp3_probe(struct spi_device *spi)
 188 {
 189         struct fpga_data *data;
 190         int err;
 191
 192         data = devm_kzalloc(&spi->dev, sizeof(*data), GFP_KERNEL);
 193         if (!data) {
 194                 dev_err(&spi->dev, "Memory allocation for fpga_data failed\n");
 195                 return -ENOMEM;
 196         }
 197         spi_set_drvdata(spi, data);
 198
 199         init_completion(&data->fw_loaded);
 200         err = request_firmware_nowait(THIS_MODULE, FW_ACTION_NOHOTPLUG,
 201                                       FIRMWARE_NAME, &spi->dev,
 202                                       GFP_KERNEL, spi, firmware_load);
 203         if (err) {
 204                 dev_err(&spi->dev, "Firmware loading failed with %d!\n", err);
 205                 return err;
 206         }
 207
 208         dev_info(&spi->dev, "FPGA bitstream configuration driver registered\n");
 209
 210         return 0;
 211 }
 212
 213 static int lattice_ecp3_remove(struct spi_device *spi)
 214 {
 215         struct fpga_data *data = spi_get_drvdata(spi);
 216
 217         wait_for_completion(&data->fw_loaded);
 218
 219         return 0;
 220 }
 221
 222 static const struct spi_device_id lattice_ecp3_id[] = {
 223         { "ecp3-17", 0 },
 224         { "ecp3-35", 0 },
 225         { }
 226 };
 227 MODULE_DEVICE_TABLE(spi, lattice_ecp3_id);
 228
 229 static struct spi_driver lattice_ecp3_driver = {
 230         .driver = {
 231                 .name = "lattice-ecp3",
 232                 .owner = THIS_MODULE,
 233         },
 234         .probe = lattice_ecp3_probe,
 235         .remove = lattice_ecp3_remove,
 236         .id_table = lattice_ecp3_id,
 237 };
 238
 239 module_spi_driver(lattice_ecp3_driver);
 240
 241 MODULE_AUTHOR("Stefan Roese <sr@denx.de>");
 242 MODULE_DESCRIPTION("Lattice ECP3 FPGA configuration via SPI");
 243 MODULE_LICENSE("GPL");