drivers/fpga/altera-pr-ip-core.c

   1 /*
   2  * Driver for Altera Partial Reconfiguration IP Core
   3  *
   4  * Copyright (C) 2016-2017 Intel Corporation
   5  *
   6  * Based on socfpga-a10.c Copyright (C) 2015-2016 Altera Corporation
   7  *  by Alan Tull <atull@opensource.altera.com>
   8  *
   9  * This program is free software; you can redistribute it and/or modify it
  10  * under the terms and conditions of the GNU General Public License,
  11  * version 2, as published by the Free Software Foundation.
  12  *
  13  * This program is distributed in the hope it will be useful, but WITHOUT
  14  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  16  * more details.
  17  *
  18  * You should have received a copy of the GNU General Public License along with
  19  * this program.  If not, see <http://www.gnu.org/licenses/>.
  20  */
  21 #include <linux/delay.h>
  22 #include <linux/fpga/altera-pr-ip-core.h>
  23 #include <linux/fpga/fpga-mgr.h>
  24 #include <linux/module.h>
  25
  26 #define ALT_PR_DATA_OFST                0x00
  27 #define ALT_PR_CSR_OFST                 0x04
  28
  29 #define ALT_PR_CSR_PR_START             BIT(0)
  30 #define ALT_PR_CSR_STATUS_SFT           2
  31 #define ALT_PR_CSR_STATUS_MSK           (7 << ALT_PR_CSR_STATUS_SFT)
  32 #define ALT_PR_CSR_STATUS_NRESET        (0 << ALT_PR_CSR_STATUS_SFT)
  33 #define ALT_PR_CSR_STATUS_PR_ERR        (1 << ALT_PR_CSR_STATUS_SFT)
  34 #define ALT_PR_CSR_STATUS_CRC_ERR       (2 << ALT_PR_CSR_STATUS_SFT)
  35 #define ALT_PR_CSR_STATUS_BAD_BITS      (3 << ALT_PR_CSR_STATUS_SFT)
  36 #define ALT_PR_CSR_STATUS_PR_IN_PROG    (4 << ALT_PR_CSR_STATUS_SFT)
  37 #define ALT_PR_CSR_STATUS_PR_SUCCESS    (5 << ALT_PR_CSR_STATUS_SFT)
  38
  39 struct alt_pr_priv {
  40         void __iomem *reg_base;
  41 };
  42
  43 static enum fpga_mgr_states alt_pr_fpga_state(struct fpga_manager *mgr)
  44 {
  45         struct alt_pr_priv *priv = mgr->priv;
  46         const char *err = "unknown";
  47         enum fpga_mgr_states ret = FPGA_MGR_STATE_UNKNOWN;
  48         u32 val;
  49
  50         val = readl(priv->reg_base + ALT_PR_CSR_OFST);
  51
  52         val &= ALT_PR_CSR_STATUS_MSK;
  53
  54         switch (val) {
  55         case ALT_PR_CSR_STATUS_NRESET:
  56                 return FPGA_MGR_STATE_RESET;
  57
  58         case ALT_PR_CSR_STATUS_PR_ERR:
  59                 err = "pr error";
  60                 ret = FPGA_MGR_STATE_WRITE_ERR;
  61                 break;
  62
  63         case ALT_PR_CSR_STATUS_CRC_ERR:
  64                 err = "crc error";
  65                 ret = FPGA_MGR_STATE_WRITE_ERR;
  66                 break;
  67
  68         case ALT_PR_CSR_STATUS_BAD_BITS:
  69                 err = "bad bits";
  70                 ret = FPGA_MGR_STATE_WRITE_ERR;
  71                 break;
  72
  73         case ALT_PR_CSR_STATUS_PR_IN_PROG:
  74                 return FPGA_MGR_STATE_WRITE;
  75
  76         case ALT_PR_CSR_STATUS_PR_SUCCESS:
  77                 return FPGA_MGR_STATE_OPERATING;
  78
  79         default:
  80                 break;
  81         }
  82
  83         dev_err(&mgr->dev, "encountered error code %d (%s) in %s()\n",
  84                 val, err, __func__);
  85         return ret;
  86 }
  87
  88 static int alt_pr_fpga_write_init(struct fpga_manager *mgr,
  89                                   struct fpga_image_info *info,
  90                                   const char *buf, size_t count)
  91 {
  92         struct alt_pr_priv *priv = mgr->priv;
  93         u32 val;
  94
  95         if (!(info->flags & FPGA_MGR_PARTIAL_RECONFIG)) {
  96                 dev_err(&mgr->dev, "%s Partial Reconfiguration flag not set\n",
  97                         __func__);
  98                 return -EINVAL;
  99         }
 100
 101         val = readl(priv->reg_base + ALT_PR_CSR_OFST);
 102
 103         if (val & ALT_PR_CSR_PR_START) {
 104                 dev_err(&mgr->dev,
 105                         "%s Partial Reconfiguration already started\n",
 106                        __func__);
 107                 return -EINVAL;
 108         }
 109
 110         writel(val | ALT_PR_CSR_PR_START, priv->reg_base + ALT_PR_CSR_OFST);
 111
 112         return 0;
 113 }
 114
 115 static int alt_pr_fpga_write(struct fpga_manager *mgr, const char *buf,
 116                              size_t count)
 117 {
 118         struct alt_pr_priv *priv = mgr->priv;
 119         u32 *buffer_32 = (u32 *)buf;
 120         size_t i = 0;
 121
 122         if (count <= 0)
 123                 return -EINVAL;
 124
 125         /* Write out the complete 32-bit chunks */
 126         while (count >= sizeof(u32)) {
 127                 writel(buffer_32[i++], priv->reg_base);
 128                 count -= sizeof(u32);
 129         }
 130
 131         /* Write out remaining non 32-bit chunks */
 132         switch (count) {
 133         case 3:
 134                 writel(buffer_32[i++] & 0x00ffffff, priv->reg_base);
 135                 break;
 136         case 2:
 137                 writel(buffer_32[i++] & 0x0000ffff, priv->reg_base);
 138                 break;
 139         case 1:
 140                 writel(buffer_32[i++] & 0x000000ff, priv->reg_base);
 141                 break;
 142         case 0:
 143                 break;
 144         default:
 145                 /* This will never happen */
 146                 return -EFAULT;
 147         }
 148
 149         if (alt_pr_fpga_state(mgr) == FPGA_MGR_STATE_WRITE_ERR)
 150                 return -EIO;
 151
 152         return 0;
 153 }
 154
 155 static int alt_pr_fpga_write_complete(struct fpga_manager *mgr,
 156                                       struct fpga_image_info *info)
 157 {
 158         u32 i = 0;
 159
 160         do {
 161                 switch (alt_pr_fpga_state(mgr)) {
 162                 case FPGA_MGR_STATE_WRITE_ERR:
 163                         return -EIO;
 164
 165                 case FPGA_MGR_STATE_OPERATING:
 166                         dev_info(&mgr->dev,
 167                                  "successful partial reconfiguration\n");
 168                         return 0;
 169
 170                 default:
 171                         break;
 172                 }
 173                 udelay(1);
 174         } while (info->config_complete_timeout_us > i++);
 175
 176         dev_err(&mgr->dev, "timed out waiting for write to complete\n");
 177         return -ETIMEDOUT;
 178 }
 179
 180 static const struct fpga_manager_ops alt_pr_ops = {
 181         .state = alt_pr_fpga_state,
 182         .write_init = alt_pr_fpga_write_init,
 183         .write = alt_pr_fpga_write,
 184         .write_complete = alt_pr_fpga_write_complete,
 185 };
 186
 187 int alt_pr_register(struct device *dev, void __iomem *reg_base)
 188 {
 189         struct alt_pr_priv *priv;
 190         u32 val;
 191
 192         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 193         if (!priv)
 194                 return -ENOMEM;
 195
 196         priv->reg_base = reg_base;
 197
 198         val = readl(priv->reg_base + ALT_PR_CSR_OFST);
 199
 200         dev_dbg(dev, "%s status=%d start=%d\n", __func__,
 201                 (val & ALT_PR_CSR_STATUS_MSK) >> ALT_PR_CSR_STATUS_SFT,
 202                 (int)(val & ALT_PR_CSR_PR_START));
 203
 204         return fpga_mgr_register(dev, dev_name(dev), &alt_pr_ops, priv);
 205 }
 206 EXPORT_SYMBOL_GPL(alt_pr_register);
 207
 208 int alt_pr_unregister(struct device *dev)
 209 {
 210         dev_dbg(dev, "%s\n", __func__);
 211
 212         fpga_mgr_unregister(dev);
 213
 214         return 0;
 215 }
 216 EXPORT_SYMBOL_GPL(alt_pr_unregister);
 217
 218 MODULE_AUTHOR("Matthew Gerlach <matthew.gerlach@linux.intel.com>");
 219 MODULE_DESCRIPTION("Altera Partial Reconfiguration IP Core");
 220 MODULE_LICENSE("GPL v2");