drivers/misc/xilinx_sdfec.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Xilinx SDFEC
   4  *
   5  * Copyright (C) 2019 Xilinx, Inc.
   6  *
   7  * Description:
   8  * This driver is developed for SDFEC16 (Soft Decision FEC 16nm)
   9  * IP. It exposes a char device which supports file operations
  10  * like  open(), close() and ioctl().
  11  */
  12
  13 #include <linux/miscdevice.h>
  14 #include <linux/io.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/kernel.h>
  17 #include <linux/module.h>
  18 #include <linux/of_platform.h>
  19 #include <linux/poll.h>
  20 #include <linux/slab.h>
  21 #include <linux/clk.h>
  22
  23 #define DEV_NAME_LEN 12
  24
  25 static struct idr dev_idr;
  26 static struct mutex dev_idr_lock;
  27
  28 /**
  29  * struct xsdfec_clks - For managing SD-FEC clocks
  30  * @core_clk: Main processing clock for core
  31  * @axi_clk: AXI4-Lite memory-mapped clock
  32  * @din_words_clk: DIN Words AXI4-Stream Slave clock
  33  * @din_clk: DIN AXI4-Stream Slave clock
  34  * @dout_clk: DOUT Words AXI4-Stream Slave clock
  35  * @dout_words_clk: DOUT AXI4-Stream Slave clock
  36  * @ctrl_clk: Control AXI4-Stream Slave clock
  37  * @status_clk: Status AXI4-Stream Slave clock
  38  */
  39 struct xsdfec_clks {
  40         struct clk *core_clk;
  41         struct clk *axi_clk;
  42         struct clk *din_words_clk;
  43         struct clk *din_clk;
  44         struct clk *dout_clk;
  45         struct clk *dout_words_clk;
  46         struct clk *ctrl_clk;
  47         struct clk *status_clk;
  48 };
  49
  50 /**
  51  * struct xsdfec_dev - Driver data for SDFEC
  52  * @regs: device physical base address
  53  * @dev: pointer to device struct
  54  * @miscdev: Misc device handle
  55  * @error_data_lock: Error counter and states spinlock
  56  * @clks: Clocks managed by the SDFEC driver
  57  * @dev_name: Device name
  58  * @dev_id: Device ID
  59  *
  60  * This structure contains necessary state for SDFEC driver to operate
  61  */
  62 struct xsdfec_dev {
  63         void __iomem *regs;
  64         struct device *dev;
  65         struct miscdevice miscdev;
  66         /* Spinlock to protect state_updated and stats_updated */
  67         spinlock_t error_data_lock;
  68         struct xsdfec_clks clks;
  69         char dev_name[DEV_NAME_LEN];
  70         int dev_id;
  71 };
  72
  73 static const struct file_operations xsdfec_fops = {
  74         .owner = THIS_MODULE,
  75 };
  76
  77 static int xsdfec_clk_init(struct platform_device *pdev,
  78                            struct xsdfec_clks *clks)
  79 {
  80         int err;
  81
  82         clks->core_clk = devm_clk_get(&pdev->dev, "core_clk");
  83         if (IS_ERR(clks->core_clk)) {
  84                 dev_err(&pdev->dev, "failed to get core_clk");
  85                 return PTR_ERR(clks->core_clk);
  86         }
  87
  88         clks->axi_clk = devm_clk_get(&pdev->dev, "s_axi_aclk");
  89         if (IS_ERR(clks->axi_clk)) {
  90                 dev_err(&pdev->dev, "failed to get axi_clk");
  91                 return PTR_ERR(clks->axi_clk);
  92         }
  93
  94         clks->din_words_clk = devm_clk_get(&pdev->dev, "s_axis_din_words_aclk");
  95         if (IS_ERR(clks->din_words_clk)) {
  96                 if (PTR_ERR(clks->din_words_clk) != -ENOENT) {
  97                         err = PTR_ERR(clks->din_words_clk);
  98                         return err;
  99                 }
 100                 clks->din_words_clk = NULL;
 101         }
 102
 103         clks->din_clk = devm_clk_get(&pdev->dev, "s_axis_din_aclk");
 104         if (IS_ERR(clks->din_clk)) {
 105                 if (PTR_ERR(clks->din_clk) != -ENOENT) {
 106                         err = PTR_ERR(clks->din_clk);
 107                         return err;
 108                 }
 109                 clks->din_clk = NULL;
 110         }
 111
 112         clks->dout_clk = devm_clk_get(&pdev->dev, "m_axis_dout_aclk");
 113         if (IS_ERR(clks->dout_clk)) {
 114                 if (PTR_ERR(clks->dout_clk) != -ENOENT) {
 115                         err = PTR_ERR(clks->dout_clk);
 116                         return err;
 117                 }
 118                 clks->dout_clk = NULL;
 119         }
 120
 121         clks->dout_words_clk =
 122                 devm_clk_get(&pdev->dev, "s_axis_dout_words_aclk");
 123         if (IS_ERR(clks->dout_words_clk)) {
 124                 if (PTR_ERR(clks->dout_words_clk) != -ENOENT) {
 125                         err = PTR_ERR(clks->dout_words_clk);
 126                         return err;
 127                 }
 128                 clks->dout_words_clk = NULL;
 129         }
 130
 131         clks->ctrl_clk = devm_clk_get(&pdev->dev, "s_axis_ctrl_aclk");
 132         if (IS_ERR(clks->ctrl_clk)) {
 133                 if (PTR_ERR(clks->ctrl_clk) != -ENOENT) {
 134                         err = PTR_ERR(clks->ctrl_clk);
 135                         return err;
 136                 }
 137                 clks->ctrl_clk = NULL;
 138         }
 139
 140         clks->status_clk = devm_clk_get(&pdev->dev, "m_axis_status_aclk");
 141         if (IS_ERR(clks->status_clk)) {
 142                 if (PTR_ERR(clks->status_clk) != -ENOENT) {
 143                         err = PTR_ERR(clks->status_clk);
 144                         return err;
 145                 }
 146                 clks->status_clk = NULL;
 147         }
 148
 149         err = clk_prepare_enable(clks->core_clk);
 150         if (err) {
 151                 dev_err(&pdev->dev, "failed to enable core_clk (%d)", err);
 152                 return err;
 153         }
 154
 155         err = clk_prepare_enable(clks->axi_clk);
 156         if (err) {
 157                 dev_err(&pdev->dev, "failed to enable axi_clk (%d)", err);
 158                 goto err_disable_core_clk;
 159         }
 160
 161         err = clk_prepare_enable(clks->din_clk);
 162         if (err) {
 163                 dev_err(&pdev->dev, "failed to enable din_clk (%d)", err);
 164                 goto err_disable_axi_clk;
 165         }
 166
 167         err = clk_prepare_enable(clks->din_words_clk);
 168         if (err) {
 169                 dev_err(&pdev->dev, "failed to enable din_words_clk (%d)", err);
 170                 goto err_disable_din_clk;
 171         }
 172
 173         err = clk_prepare_enable(clks->dout_clk);
 174         if (err) {
 175                 dev_err(&pdev->dev, "failed to enable dout_clk (%d)", err);
 176                 goto err_disable_din_words_clk;
 177         }
 178
 179         err = clk_prepare_enable(clks->dout_words_clk);
 180         if (err) {
 181                 dev_err(&pdev->dev, "failed to enable dout_words_clk (%d)",
 182                         err);
 183                 goto err_disable_dout_clk;
 184         }
 185
 186         err = clk_prepare_enable(clks->ctrl_clk);
 187         if (err) {
 188                 dev_err(&pdev->dev, "failed to enable ctrl_clk (%d)", err);
 189                 goto err_disable_dout_words_clk;
 190         }
 191
 192         err = clk_prepare_enable(clks->status_clk);
 193         if (err) {
 194                 dev_err(&pdev->dev, "failed to enable status_clk (%d)\n", err);
 195                 goto err_disable_ctrl_clk;
 196         }
 197
 198         return err;
 199
 200 err_disable_ctrl_clk:
 201         clk_disable_unprepare(clks->ctrl_clk);
 202 err_disable_dout_words_clk:
 203         clk_disable_unprepare(clks->dout_words_clk);
 204 err_disable_dout_clk:
 205         clk_disable_unprepare(clks->dout_clk);
 206 err_disable_din_words_clk:
 207         clk_disable_unprepare(clks->din_words_clk);
 208 err_disable_din_clk:
 209         clk_disable_unprepare(clks->din_clk);
 210 err_disable_axi_clk:
 211         clk_disable_unprepare(clks->axi_clk);
 212 err_disable_core_clk:
 213         clk_disable_unprepare(clks->core_clk);
 214
 215         return err;
 216 }
 217
 218 static void xsdfec_disable_all_clks(struct xsdfec_clks *clks)
 219 {
 220         clk_disable_unprepare(clks->status_clk);
 221         clk_disable_unprepare(clks->ctrl_clk);
 222         clk_disable_unprepare(clks->dout_words_clk);
 223         clk_disable_unprepare(clks->dout_clk);
 224         clk_disable_unprepare(clks->din_words_clk);
 225         clk_disable_unprepare(clks->din_clk);
 226         clk_disable_unprepare(clks->core_clk);
 227         clk_disable_unprepare(clks->axi_clk);
 228 }
 229
 230 static void xsdfec_idr_remove(struct xsdfec_dev *xsdfec)
 231 {
 232         mutex_lock(&dev_idr_lock);
 233         idr_remove(&dev_idr, xsdfec->dev_id);
 234         mutex_unlock(&dev_idr_lock);
 235 }
 236
 237 static int xsdfec_probe(struct platform_device *pdev)
 238 {
 239         struct xsdfec_dev *xsdfec;
 240         struct device *dev;
 241         struct resource *res;
 242         int err;
 243
 244         xsdfec = devm_kzalloc(&pdev->dev, sizeof(*xsdfec), GFP_KERNEL);
 245         if (!xsdfec)
 246                 return -ENOMEM;
 247
 248         xsdfec->dev = &pdev->dev;
 249         spin_lock_init(&xsdfec->error_data_lock);
 250
 251         err = xsdfec_clk_init(pdev, &xsdfec->clks);
 252         if (err)
 253                 return err;
 254
 255         dev = xsdfec->dev;
 256         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 257         xsdfec->regs = devm_ioremap_resource(dev, res);
 258         if (IS_ERR(xsdfec->regs)) {
 259                 err = PTR_ERR(xsdfec->regs);
 260                 goto err_xsdfec_dev;
 261         }
 262
 263         /* Save driver private data */
 264         platform_set_drvdata(pdev, xsdfec);
 265
 266         mutex_lock(&dev_idr_lock);
 267         err = idr_alloc(&dev_idr, xsdfec->dev_name, 0, 0, GFP_KERNEL);
 268         mutex_unlock(&dev_idr_lock);
 269         if (err < 0)
 270                 goto err_xsdfec_dev;
 271         xsdfec->dev_id = err;
 272
 273         snprintf(xsdfec->dev_name, DEV_NAME_LEN, "xsdfec%d", xsdfec->dev_id);
 274         xsdfec->miscdev.minor = MISC_DYNAMIC_MINOR;
 275         xsdfec->miscdev.name = xsdfec->dev_name;
 276         xsdfec->miscdev.fops = &xsdfec_fops;
 277         xsdfec->miscdev.parent = dev;
 278         err = misc_register(&xsdfec->miscdev);
 279         if (err) {
 280                 dev_err(dev, "error:%d. Unable to register device", err);
 281                 goto err_xsdfec_idr;
 282         }
 283         return 0;
 284
 285 err_xsdfec_idr:
 286         xsdfec_idr_remove(xsdfec);
 287 err_xsdfec_dev:
 288         xsdfec_disable_all_clks(&xsdfec->clks);
 289         return err;
 290 }
 291
 292 static int xsdfec_remove(struct platform_device *pdev)
 293 {
 294         struct xsdfec_dev *xsdfec;
 295
 296         xsdfec = platform_get_drvdata(pdev);
 297         misc_deregister(&xsdfec->miscdev);
 298         xsdfec_idr_remove(xsdfec);
 299         xsdfec_disable_all_clks(&xsdfec->clks);
 300         return 0;
 301 }
 302
 303 static const struct of_device_id xsdfec_of_match[] = {
 304         {
 305                 .compatible = "xlnx,sd-fec-1.1",
 306         },
 307         { /* end of table */ }
 308 };
 309 MODULE_DEVICE_TABLE(of, xsdfec_of_match);
 310
 311 static struct platform_driver xsdfec_driver = {
 312         .driver = {
 313                 .name = "xilinx-sdfec",
 314                 .of_match_table = xsdfec_of_match,
 315         },
 316         .probe = xsdfec_probe,
 317         .remove =  xsdfec_remove,
 318 };
 319
 320 static int __init xsdfec_init(void)
 321 {
 322         int err;
 323
 324         mutex_init(&dev_idr_lock);
 325         idr_init(&dev_idr);
 326         err = platform_driver_register(&xsdfec_driver);
 327         if (err < 0) {
 328                 pr_err("%s Unabled to register SDFEC driver", __func__);
 329                 return err;
 330         }
 331         return 0;
 332 }
 333
 334 static void __exit xsdfec_exit(void)
 335 {
 336         platform_driver_unregister(&xsdfec_driver);
 337         idr_destroy(&dev_idr);
 338 }
 339
 340 module_init(xsdfec_init);
 341 module_exit(xsdfec_exit);
 342
 343 MODULE_AUTHOR("Xilinx, Inc");
 344 MODULE_DESCRIPTION("Xilinx SD-FEC16 Driver");
 345 MODULE_LICENSE("GPL");