target/linux/layerscape/patches-5.4/701-net-0308-staging-fsl_ppfe-add-support-for-a-char-dev-for-link.patch

   1 From a41d4af2ed4b02edca9d7f69955893d407274dc2 Mon Sep 17 00:00:00 2001
   2 From: Shreyansh Jain <shreyansh.jain@nxp.com>
   3 Date: Wed, 6 Jun 2018 14:19:34 +0530
   4 Subject: [PATCH] staging: fsl_ppfe: add support for a char dev for link status
   5
   6 Read and IOCTL support is added. Application would need to open,
   7 read/ioctl the /dev/pfe_us_cdev device.
   8 select is pending as it requires a wait_queue.
   9
  10 Signed-off-by: Shreyansh Jain <shreyansh.jain@nxp.com>
  11 Signed-off-by: Calvin Johnson <calvin.johnson@nxp.com>
  12 ---
  13  drivers/staging/fsl_ppfe/Makefile   |   3 +-
  14  drivers/staging/fsl_ppfe/pfe_cdev.c | 207 ++++++++++++++++++++++++++++++++++++
  15  drivers/staging/fsl_ppfe/pfe_cdev.h |  52 +++++++++
  16  drivers/staging/fsl_ppfe/pfe_eth.c  |  14 +++
  17  drivers/staging/fsl_ppfe/pfe_mod.c  |  14 +++
  18  5 files changed, 289 insertions(+), 1 deletion(-)
  19  create mode 100644 drivers/staging/fsl_ppfe/pfe_cdev.c
  20  create mode 100644 drivers/staging/fsl_ppfe/pfe_cdev.h
  21
  22 --- a/drivers/staging/fsl_ppfe/Makefile
  23 +++ b/drivers/staging/fsl_ppfe/Makefile
  24 @@ -16,4 +16,5 @@ pfe-y += pfe_mod.o \
  25         pfe_sysfs.o \
  26         pfe_debugfs.o \
  27         pfe_ls1012a_platform.o \
  28 -       pfe_hal.o
  29 +       pfe_hal.o \
  30 +       pfe_cdev.o
  31 --- /dev/null
  32 +++ b/drivers/staging/fsl_ppfe/pfe_cdev.c
  33 @@ -0,0 +1,207 @@
  34 +/*
  35 + * Copyright 2018 NXP
  36 + *
  37 + * This program is free software; you can redistribute it and/or modify
  38 + * it under the terms of the GNU General Public License as published by
  39 + * the Free Software Foundation; either version 2 of the License, or
  40 + * (at your option) any later version.
  41 + *
  42 + * This program is distributed in the hope that it will be useful,
  43 + * but WITHOUT ANY WARRANTY; without even the implied warranty of
  44 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  45 + * GNU General Public License for more details.
  46 + *
  47 + * You should have received a copy of the GNU General Public License
  48 + * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  49 + */
  50 +
  51 +/* @pfe_cdev.c.
  52 + *  Dummy device representing the PFE US in userspace.
  53 + *  - used for interacting with the kernel layer for link status
  54 + */
  55 +
  56 +#include "pfe_cdev.h"
  57 +
  58 +static int pfe_majno;
  59 +static struct class *pfe_char_class;
  60 +static struct device *pfe_char_dev;
  61 +
  62 +struct pfe_shared_info link_states[PFE_CDEV_ETH_COUNT];
  63 +
  64 +static int pfe_cdev_open(struct inode *inp, struct file *fp)
  65 +{
  66 +       pr_debug("PFE CDEV device opened.\n");
  67 +       return 0;
  68 +}
  69 +
  70 +static ssize_t pfe_cdev_read(struct file *fp, char *buf,
  71 +                            size_t len, loff_t *off)
  72 +{
  73 +       int ret = 0;
  74 +
  75 +       pr_info("PFE CDEV attempt copying (%lu) size of user.\n",
  76 +               sizeof(link_states));
  77 +
  78 +       pr_debug("Dump link_state on screen before copy_to_user\n");
  79 +       for (; ret < PFE_CDEV_ETH_COUNT; ret++) {
  80 +               pr_debug("%u  %u", link_states[ret].phy_id,
  81 +                        link_states[ret].state);
  82 +               pr_debug("\n");
  83 +       }
  84 +
  85 +       /* Copy to user the value in buffer sized len */
  86 +       ret = copy_to_user(buf, &link_states, sizeof(link_states));
  87 +       if (ret != 0) {
  88 +               pr_err("Failed to send (%d)bytes of (%lu) requested.\n",
  89 +                      ret, len);
  90 +               return -EFAULT;
  91 +       }
  92 +
  93 +       /* offset set back to 0 as there is contextual reading offset */
  94 +       *off = 0;
  95 +       pr_debug("Read of (%lu) bytes performed.\n", sizeof(link_states));
  96 +
  97 +       return sizeof(link_states);
  98 +}
  99 +
 100 +/**
 101 + * This function is for getting some commands from user through non-IOCTL
 102 + * channel. It can used to configure the device.
 103 + * TODO: To be filled in future, if require duplex communication with user
 104 + * space.
 105 + */
 106 +static ssize_t pfe_cdev_write(struct file *fp, const char *buf,
 107 +                             size_t len, loff_t *off)
 108 +{
 109 +       pr_info("PFE CDEV Write operation not supported!\n");
 110 +
 111 +       return -EFAULT;
 112 +}
 113 +
 114 +static int pfe_cdev_release(struct inode *inp, struct file *fp)
 115 +{
 116 +       pr_info("PFE_CDEV: Device successfully closed\n");
 117 +       return 0;
 118 +}
 119 +
 120 +static long pfe_cdev_ioctl(struct file *fp, unsigned int cmd,
 121 +                          unsigned long arg)
 122 +{
 123 +       int ret = -EFAULT;
 124 +       int __user *argp = (int __user *)arg;
 125 +
 126 +       pr_debug("PFE CDEV IOCTL Called with cmd=(%u)\n", cmd);
 127 +
 128 +       switch (cmd) {
 129 +       case PFE_CDEV_ETH0_STATE_GET:
 130 +               /* Return an unsigned int (link state) for ETH0 */
 131 +               *argp = link_states[0].state;
 132 +               pr_debug("Returning state=%d for ETH0\n", *argp);
 133 +               ret = 0;
 134 +               break;
 135 +       case PFE_CDEV_ETH1_STATE_GET:
 136 +               /* Return an unsigned int (link state) for ETH0 */
 137 +               *argp = link_states[1].state;
 138 +               pr_debug("Returning state=%d for ETH1\n", *argp);
 139 +               ret = 0;
 140 +               break;
 141 +       default:
 142 +               pr_info("Unsupport cmd (%d) for PFE CDEV.\n", cmd);
 143 +               break;
 144 +       };
 145 +
 146 +       return ret;
 147 +}
 148 +
 149 +static unsigned int pfe_cdev_poll(struct file *fp,
 150 +                                 struct poll_table_struct *wait)
 151 +{
 152 +       pr_info("PFE CDEV poll method not supported\n");
 153 +       return 0;
 154 +}
 155 +
 156 +static const struct file_operations pfe_cdev_fops = {
 157 +       .open = pfe_cdev_open,
 158 +       .read = pfe_cdev_read,
 159 +       .write = pfe_cdev_write,
 160 +       .release = pfe_cdev_release,
 161 +       .unlocked_ioctl = pfe_cdev_ioctl,
 162 +       .poll = pfe_cdev_poll,
 163 +};
 164 +
 165 +int pfe_cdev_init(void)
 166 +{
 167 +       int ret;
 168 +
 169 +       pr_debug("PFE CDEV initialization begin\n");
 170 +
 171 +       /* Register the major number for the device */
 172 +       pfe_majno = register_chrdev(0, PFE_CDEV_NAME, &pfe_cdev_fops);
 173 +       if (pfe_majno < 0) {
 174 +               pr_err("Unable to register PFE CDEV. PFE CDEV not available\n");
 175 +               ret = pfe_majno;
 176 +               goto cleanup;
 177 +       }
 178 +
 179 +       pr_debug("PFE CDEV assigned major number: %d\n", pfe_majno);
 180 +
 181 +       /* Register the class for the device */
 182 +       pfe_char_class = class_create(THIS_MODULE, PFE_CLASS_NAME);
 183 +       if (IS_ERR(pfe_char_class)) {
 184 +               pr_err(
 185 +               "Failed to init class for PFE CDEV. PFE CDEV not available.\n");
 186 +               goto cleanup;
 187 +       }
 188 +
 189 +       pr_debug("PFE CDEV Class created successfully.\n");
 190 +
 191 +       /* Create the device without any parent and without any callback data */
 192 +           pfe_char_dev = device_create(pfe_char_class, NULL,
 193 +                                        MKDEV(pfe_majno, 0), NULL,
 194 +                                        PFE_CDEV_NAME);
 195 +       if (IS_ERR(pfe_char_dev)) {
 196 +               pr_err("Unable to PFE CDEV device. PFE CDEV not available.\n");
 197 +               ret = PTR_ERR(pfe_char_dev);
 198 +               goto cleanup;
 199 +       }
 200 +
 201 +       /* Information structure being shared with the userspace */
 202 +       memset(link_states, 0, sizeof(struct pfe_shared_info) *
 203 +                       PFE_CDEV_ETH_COUNT);
 204 +
 205 +       pr_info("PFE CDEV created: %s\n", PFE_CDEV_NAME);
 206 +
 207 +       ret = 0;
 208 +       return ret;
 209 +
 210 +cleanup:
 211 +       if (!IS_ERR(pfe_char_class))
 212 +               class_destroy(pfe_char_class);
 213 +
 214 +       if (pfe_majno > 0)
 215 +               unregister_chrdev(pfe_majno, PFE_CDEV_NAME);
 216 +
 217 +       ret = -EFAULT;
 218 +       return ret;
 219 +}
 220 +
 221 +void pfe_cdev_exit(void)
 222 +{
 223 +       if (!IS_ERR(pfe_char_dev))
 224 +               device_destroy(pfe_char_class, MKDEV(pfe_majno, 0));
 225 +
 226 +       if (!IS_ERR(pfe_char_class)) {
 227 +               class_unregister(pfe_char_class);
 228 +               class_destroy(pfe_char_class);
 229 +       }
 230 +
 231 +       if (pfe_majno > 0)
 232 +               unregister_chrdev(pfe_majno, PFE_CDEV_NAME);
 233 +
 234 +       /* reset the variables */
 235 +       pfe_majno = 0;
 236 +       pfe_char_class = NULL;
 237 +       pfe_char_dev = NULL;
 238 +
 239 +       pr_info("PFE CDEV Removed.\n");
 240 +}
 241 --- /dev/null
 242 +++ b/drivers/staging/fsl_ppfe/pfe_cdev.h
 243 @@ -0,0 +1,52 @@
 244 +/*
 245 + * Copyright 2018 NXP
 246 + *
 247 + * This program is free software; you can redistribute it and/or modify
 248 + * it under the terms of the GNU General Public License as published by
 249 + * the Free Software Foundation; either version 2 of the License, or
 250 + * (at your option) any later version.
 251 + *
 252 + * This program is distributed in the hope that it will be useful,
 253 + * but WITHOUT ANY WARRANTY; without even the implied warranty of
 254 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 255 + * GNU General Public License for more details.
 256 + *
 257 + * You should have received a copy of the GNU General Public License
 258 + * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 259 + */
 260 +
 261 +#ifndef _PFE_CDEV_H_
 262 +#define _PFE_CDEV_H_
 263 +
 264 +#include <linux/init.h>
 265 +#include <linux/device.h>
 266 +#include <linux/err.h>
 267 +#include <linux/kernel.h>
 268 +#include <linux/fs.h>
 269 +#include <linux/uaccess.h>
 270 +#include <linux/poll.h>
 271 +
 272 +#define  PFE_CDEV_NAME "pfe_us_cdev"
 273 +#define  PFE_CLASS_NAME  "ppfe_us"
 274 +
 275 +/* Extracted from ls1012a_pfe_platform_data, there are 3 interfaces which are
 276 + * supported by PFE driver. Should be updated if number of eth devices are
 277 + * changed.
 278 + */
 279 +#define PFE_CDEV_ETH_COUNT 3
 280 +
 281 +struct pfe_shared_info {
 282 +       uint32_t phy_id; /* Link phy ID */
 283 +       uint8_t state;  /* Has either 0 or 1 */
 284 +};
 285 +
 286 +extern struct pfe_shared_info link_states[PFE_CDEV_ETH_COUNT];
 287 +
 288 +/* IOCTL Commands */
 289 +#define PFE_CDEV_ETH0_STATE_GET        0
 290 +#define PFE_CDEV_ETH1_STATE_GET        1
 291 +
 292 +int pfe_cdev_init(void);
 293 +void pfe_cdev_exit(void);
 294 +
 295 +#endif /* _PFE_CDEV_H_ */
 296 --- a/drivers/staging/fsl_ppfe/pfe_eth.c
 297 +++ b/drivers/staging/fsl_ppfe/pfe_eth.c
 298 @@ -55,6 +55,7 @@
 299
 300  #include "pfe_mod.h"
 301  #include "pfe_eth.h"
 302 +#include "pfe_cdev.h"
 303
 304  #define LS1012A_REV_1_0                0x87040010
 305
 306 @@ -1160,6 +1161,19 @@ static void pfe_eth_adjust_link(struct n
 307                 phy_print_status(phydev);
 308
 309         spin_unlock_irqrestore(&priv->lock, flags);
 310 +
 311 +       /* Now, dump the details to the cdev.
 312 +        * XXX: Locking would be required? (uniprocess arch)
 313 +        *      Or, maybe move it in spinlock above
 314 +        */
 315 +       if (us && priv->einfo->gem_id < PFE_CDEV_ETH_COUNT) {
 316 +               pr_debug("Changing link state from (%u) to (%u) for ID=(%u)\n",
 317 +                        link_states[priv->einfo->gem_id].state,
 318 +                        phydev->link,
 319 +                        priv->einfo->gem_id);
 320 +               link_states[priv->einfo->gem_id].phy_id = priv->einfo->gem_id;
 321 +               link_states[priv->einfo->gem_id].state = phydev->link;
 322 +       }
 323  }
 324
 325  /* pfe_phy_exit
 326 --- a/drivers/staging/fsl_ppfe/pfe_mod.c
 327 +++ b/drivers/staging/fsl_ppfe/pfe_mod.c
 328 @@ -18,6 +18,7 @@
 329
 330  #include <linux/dma-mapping.h>
 331  #include "pfe_mod.h"
 332 +#include "pfe_cdev.h"
 333
 334  unsigned int us;
 335  module_param(us, uint, 0444);
 336 @@ -92,8 +93,18 @@ firmware_init:
 337         if (rc < 0)
 338                 goto err_debugfs;
 339
 340 +       if (us) {
 341 +               /* Creating a character device */
 342 +               rc = pfe_cdev_init();
 343 +               if (rc < 0)
 344 +                       goto err_cdev;
 345 +       }
 346 +
 347         return 0;
 348
 349 +err_cdev:
 350 +       pfe_debugfs_exit(pfe);
 351 +
 352  err_debugfs:
 353         pfe_sysfs_exit(pfe);
 354
 355 @@ -129,6 +140,9 @@ int pfe_remove(struct pfe *pfe)
 356  {
 357         pr_info("%s\n", __func__);
 358
 359 +       if (us)
 360 +               pfe_cdev_exit();
 361 +
 362         pfe_debugfs_exit(pfe);
 363
 364         pfe_sysfs_exit(pfe);