root/drivers/media/platform/marvell-ccic/mmp-driver.c

DEFINITIONS

1. mcam_to_cam
2. mmpcam_add_device
3. mmpcam_remove_device
4. mmpcam_find_device
5. mmpcam_calc_dphy
6. mmpcam_irq
7. mcam_init_clk
8. mmpcam_probe
9. mmpcam_remove
10. mmpcam_platform_remove
11. mmpcam_suspend
12. mmpcam_resume
13. mmpcam_init_module
14. mmpcam_exit_module

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Support for the camera device found on Marvell MMP processors; known
   4  * to work with the Armada 610 as used in the OLPC 1.75 system.
   5  *
   6  * Copyright 2011 Jonathan Corbet <corbet@lwn.net>
   7  * Copyright 2018 Lubomir Rintel <lkundrak@v3.sk>
   8  */
   9 
  10 #include <linux/init.h>
  11 #include <linux/kernel.h>
  12 #include <linux/module.h>
  13 #include <linux/interrupt.h>
  14 #include <linux/spinlock.h>
  15 #include <linux/slab.h>
  16 #include <linux/videodev2.h>
  17 #include <media/v4l2-device.h>
  18 #include <linux/platform_data/media/mmp-camera.h>
  19 #include <linux/device.h>
  20 #include <linux/of.h>
  21 #include <linux/of_platform.h>
  22 #include <linux/platform_device.h>
  23 #include <linux/io.h>
  24 #include <linux/list.h>
  25 #include <linux/pm.h>
  26 #include <linux/clk.h>
  27 
  28 #include "mcam-core.h"
  29 
  30 MODULE_ALIAS("platform:mmp-camera");
  31 MODULE_AUTHOR("Jonathan Corbet <corbet@lwn.net>");
  32 MODULE_LICENSE("GPL");
  33 
  34 static char *mcam_clks[] = {"axi", "func", "phy"};
  35 
  36 struct mmp_camera {
  37         struct platform_device *pdev;
  38         struct mcam_camera mcam;
  39         struct list_head devlist;
  40         struct clk *mipi_clk;
  41         int irq;
  42 };
  43 
  44 static inline struct mmp_camera *mcam_to_cam(struct mcam_camera *mcam)
  45 {
  46         return container_of(mcam, struct mmp_camera, mcam);
  47 }
  48 
  49 /*
  50  * A silly little infrastructure so we can keep track of our devices.
  51  * Chances are that we will never have more than one of them, but
  52  * the Armada 610 *does* have two controllers...
  53  */
  54 
  55 static LIST_HEAD(mmpcam_devices);
  56 static struct mutex mmpcam_devices_lock;
  57 
  58 static void mmpcam_add_device(struct mmp_camera *cam)
  59 {
  60         mutex_lock(&mmpcam_devices_lock);
  61         list_add(&cam->devlist, &mmpcam_devices);
  62         mutex_unlock(&mmpcam_devices_lock);
  63 }
  64 
  65 static void mmpcam_remove_device(struct mmp_camera *cam)
  66 {
  67         mutex_lock(&mmpcam_devices_lock);
  68         list_del(&cam->devlist);
  69         mutex_unlock(&mmpcam_devices_lock);
  70 }
  71 
  72 /*
  73  * Platform dev remove passes us a platform_device, and there's
  74  * no handy unused drvdata to stash a backpointer in.  So just
  75  * dig it out of our list.
  76  */
  77 static struct mmp_camera *mmpcam_find_device(struct platform_device *pdev)
  78 {
  79         struct mmp_camera *cam;
  80 
  81         mutex_lock(&mmpcam_devices_lock);
  82         list_for_each_entry(cam, &mmpcam_devices, devlist) {
  83                 if (cam->pdev == pdev) {
  84                         mutex_unlock(&mmpcam_devices_lock);
  85                         return cam;
  86                 }
  87         }
  88         mutex_unlock(&mmpcam_devices_lock);
  89         return NULL;
  90 }
  91 
  92 /*
  93  * calc the dphy register values
  94  * There are three dphy registers being used.
  95  * dphy[0] - CSI2_DPHY3
  96  * dphy[1] - CSI2_DPHY5
  97  * dphy[2] - CSI2_DPHY6
  98  * CSI2_DPHY3 and CSI2_DPHY6 can be set with a default value
  99  * or be calculated dynamically
 100  */
 101 static void mmpcam_calc_dphy(struct mcam_camera *mcam)
 102 {
 103         struct mmp_camera *cam = mcam_to_cam(mcam);
 104         struct mmp_camera_platform_data *pdata = cam->pdev->dev.platform_data;
 105         struct device *dev = &cam->pdev->dev;
 106         unsigned long tx_clk_esc;
 107 
 108         /*
 109          * If CSI2_DPHY3 is calculated dynamically,
 110          * pdata->lane_clk should be already set
 111          * either in the board driver statically
 112          * or in the sensor driver dynamically.
 113          */
 114         /*
 115          * dphy[0] - CSI2_DPHY3:
 116          *  bit 0 ~ bit 7: HS Term Enable.
 117          *   defines the time that the DPHY
 118          *   wait before enabling the data
 119          *   lane termination after detecting
 120          *   that the sensor has driven the data
 121          *   lanes to the LP00 bridge state.
 122          *   The value is calculated by:
 123          *   (Max T(D_TERM_EN)/Period(DDR)) - 1
 124          *  bit 8 ~ bit 15: HS_SETTLE
 125          *   Time interval during which the HS
 126          *   receiver shall ignore any Data Lane
 127          *   HS transitions.
 128          *   The value has been calibrated on
 129          *   different boards. It seems to work well.
 130          *
 131          *  More detail please refer
 132          *  MIPI Alliance Spectification for D-PHY
 133          *  document for explanation of HS-SETTLE
 134          *  and D-TERM-EN.
 135          */
 136         switch (pdata->dphy3_algo) {
 137         case DPHY3_ALGO_PXA910:
 138                 /*
 139                  * Calculate CSI2_DPHY3 algo for PXA910
 140                  */
 141                 pdata->dphy[0] =
 142                         (((1 + (pdata->lane_clk * 80) / 1000) & 0xff) << 8)
 143                         | (1 + pdata->lane_clk * 35 / 1000);
 144                 break;
 145         case DPHY3_ALGO_PXA2128:
 146                 /*
 147                  * Calculate CSI2_DPHY3 algo for PXA2128
 148                  */
 149                 pdata->dphy[0] =
 150                         (((2 + (pdata->lane_clk * 110) / 1000) & 0xff) << 8)
 151                         | (1 + pdata->lane_clk * 35 / 1000);
 152                 break;
 153         default:
 154                 /*
 155                  * Use default CSI2_DPHY3 value for PXA688/PXA988
 156                  */
 157                 dev_dbg(dev, "camera: use the default CSI2_DPHY3 value\n");
 158         }
 159 
 160         /*
 161          * mipi_clk will never be changed, it is a fixed value on MMP
 162          */
 163         if (IS_ERR(cam->mipi_clk))
 164                 return;
 165 
 166         /* get the escape clk, this is hard coded */
 167         clk_prepare_enable(cam->mipi_clk);
 168         tx_clk_esc = (clk_get_rate(cam->mipi_clk) / 1000000) / 12;
 169         clk_disable_unprepare(cam->mipi_clk);
 170         /*
 171          * dphy[2] - CSI2_DPHY6:
 172          * bit 0 ~ bit 7: CK Term Enable
 173          *  Time for the Clock Lane receiver to enable the HS line
 174          *  termination. The value is calculated similarly with
 175          *  HS Term Enable
 176          * bit 8 ~ bit 15: CK Settle
 177          *  Time interval during which the HS receiver shall ignore
 178          *  any Clock Lane HS transitions.
 179          *  The value is calibrated on the boards.
 180          */
 181         pdata->dphy[2] =
 182                 ((((534 * tx_clk_esc) / 2000 - 1) & 0xff) << 8)
 183                 | (((38 * tx_clk_esc) / 1000 - 1) & 0xff);
 184 
 185         dev_dbg(dev, "camera: DPHY sets: dphy3=0x%x, dphy5=0x%x, dphy6=0x%x\n",
 186                 pdata->dphy[0], pdata->dphy[1], pdata->dphy[2]);
 187 }
 188 
 189 static irqreturn_t mmpcam_irq(int irq, void *data)
 190 {
 191         struct mcam_camera *mcam = data;
 192         unsigned int irqs, handled;
 193 
 194         spin_lock(&mcam->dev_lock);
 195         irqs = mcam_reg_read(mcam, REG_IRQSTAT);
 196         handled = mccic_irq(mcam, irqs);
 197         spin_unlock(&mcam->dev_lock);
 198         return IRQ_RETVAL(handled);
 199 }
 200 
 201 static void mcam_init_clk(struct mcam_camera *mcam)
 202 {
 203         unsigned int i;
 204 
 205         for (i = 0; i < NR_MCAM_CLK; i++) {
 206                 if (mcam_clks[i] != NULL) {
 207                         /* Some clks are not necessary on some boards
 208                          * We still try to run even it fails getting clk
 209                          */
 210                         mcam->clk[i] = devm_clk_get(mcam->dev, mcam_clks[i]);
 211                         if (IS_ERR(mcam->clk[i]))
 212                                 dev_warn(mcam->dev, "Could not get clk: %s\n",
 213                                                 mcam_clks[i]);
 214                 }
 215         }
 216 }
 217 
 218 static int mmpcam_probe(struct platform_device *pdev)
 219 {
 220         struct mmp_camera *cam;
 221         struct mcam_camera *mcam;
 222         struct resource *res;
 223         struct fwnode_handle *ep;
 224         struct mmp_camera_platform_data *pdata;
 225         int ret;
 226 
 227         cam = devm_kzalloc(&pdev->dev, sizeof(*cam), GFP_KERNEL);
 228         if (cam == NULL)
 229                 return -ENOMEM;
 230         cam->pdev = pdev;
 231         INIT_LIST_HEAD(&cam->devlist);
 232 
 233         mcam = &cam->mcam;
 234         mcam->calc_dphy = mmpcam_calc_dphy;
 235         mcam->dev = &pdev->dev;
 236         pdata = pdev->dev.platform_data;
 237         if (pdata) {
 238                 mcam->mclk_src = pdata->mclk_src;
 239                 mcam->mclk_div = pdata->mclk_div;
 240                 mcam->bus_type = pdata->bus_type;
 241                 mcam->dphy = pdata->dphy;
 242                 mcam->lane = pdata->lane;
 243         } else {
 244                 /*
 245                  * These are values that used to be hardcoded in mcam-core and
 246                  * work well on a OLPC XO 1.75 with a parallel bus sensor.
 247                  * If it turns out other setups make sense, the values should
 248                  * be obtained from the device tree.
 249                  */
 250                 mcam->mclk_src = 3;
 251                 mcam->mclk_div = 2;
 252         }
 253         if (mcam->bus_type == V4L2_MBUS_CSI2_DPHY) {
 254                 cam->mipi_clk = devm_clk_get(mcam->dev, "mipi");
 255                 if ((IS_ERR(cam->mipi_clk) && mcam->dphy[2] == 0))
 256                         return PTR_ERR(cam->mipi_clk);
 257         }
 258         mcam->mipi_enabled = false;
 259         mcam->chip_id = MCAM_ARMADA610;
 260         mcam->buffer_mode = B_DMA_sg;
 261         strscpy(mcam->bus_info, "platform:mmp-camera", sizeof(mcam->bus_info));
 262         spin_lock_init(&mcam->dev_lock);
 263         /*
 264          * Get our I/O memory.
 265          */
 266         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 267         mcam->regs = devm_ioremap_resource(&pdev->dev, res);
 268         if (IS_ERR(mcam->regs))
 269                 return PTR_ERR(mcam->regs);
 270         mcam->regs_size = resource_size(res);
 271 
 272         mcam_init_clk(mcam);
 273 
 274         /*
 275          * Create a match of the sensor against its OF node.
 276          */
 277         ep = fwnode_graph_get_next_endpoint(of_fwnode_handle(pdev->dev.of_node),
 278                                             NULL);
 279         if (!ep)
 280                 return -ENODEV;
 281 
 282         mcam->asd.match_type = V4L2_ASYNC_MATCH_FWNODE;
 283         mcam->asd.match.fwnode = fwnode_graph_get_remote_port_parent(ep);
 284 
 285         fwnode_handle_put(ep);
 286 
 287         /*
 288          * Register the device with the core.
 289          */
 290         ret = mccic_register(mcam);
 291         if (ret)
 292                 return ret;
 293 
 294         /*
 295          * Add OF clock provider.
 296          */
 297         ret = of_clk_add_provider(pdev->dev.of_node, of_clk_src_simple_get,
 298                                                                 mcam->mclk);
 299         if (ret) {
 300                 dev_err(&pdev->dev, "can't add DT clock provider\n");
 301                 goto out;
 302         }
 303 
 304         /*
 305          * Finally, set up our IRQ now that the core is ready to
 306          * deal with it.
 307          */
 308         res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
 309         if (res == NULL) {
 310                 ret = -ENODEV;
 311                 goto out;
 312         }
 313         cam->irq = res->start;
 314         ret = devm_request_irq(&pdev->dev, cam->irq, mmpcam_irq, IRQF_SHARED,
 315                                         "mmp-camera", mcam);
 316         if (ret == 0) {
 317                 mmpcam_add_device(cam);
 318                 return 0;
 319         }
 320 
 321 out:
 322         fwnode_handle_put(mcam->asd.match.fwnode);
 323         mccic_shutdown(mcam);
 324 
 325         return ret;
 326 }
 327 
 328 
 329 static int mmpcam_remove(struct mmp_camera *cam)
 330 {
 331         struct mcam_camera *mcam = &cam->mcam;
 332 
 333         mmpcam_remove_device(cam);
 334         mccic_shutdown(mcam);
 335         return 0;
 336 }
 337 
 338 static int mmpcam_platform_remove(struct platform_device *pdev)
 339 {
 340         struct mmp_camera *cam = mmpcam_find_device(pdev);
 341 
 342         if (cam == NULL)
 343                 return -ENODEV;
 344         return mmpcam_remove(cam);
 345 }
 346 
 347 /*
 348  * Suspend/resume support.
 349  */
 350 #ifdef CONFIG_PM
 351 
 352 static int mmpcam_suspend(struct platform_device *pdev, pm_message_t state)
 353 {
 354         struct mmp_camera *cam = mmpcam_find_device(pdev);
 355 
 356         if (state.event != PM_EVENT_SUSPEND)
 357                 return 0;
 358         mccic_suspend(&cam->mcam);
 359         return 0;
 360 }
 361 
 362 static int mmpcam_resume(struct platform_device *pdev)
 363 {
 364         struct mmp_camera *cam = mmpcam_find_device(pdev);
 365 
 366         return mccic_resume(&cam->mcam);
 367 }
 368 
 369 #endif
 370 
 371 static const struct of_device_id mmpcam_of_match[] = {
 372         { .compatible = "marvell,mmp2-ccic", },
 373         {},
 374 };
 375 MODULE_DEVICE_TABLE(of, mmpcam_of_match);
 376 
 377 static struct platform_driver mmpcam_driver = {
 378         .probe          = mmpcam_probe,
 379         .remove         = mmpcam_platform_remove,
 380 #ifdef CONFIG_PM
 381         .suspend        = mmpcam_suspend,
 382         .resume         = mmpcam_resume,
 383 #endif
 384         .driver = {
 385                 .name   = "mmp-camera",
 386                 .of_match_table = of_match_ptr(mmpcam_of_match),
 387         }
 388 };
 389 
 390 
 391 static int __init mmpcam_init_module(void)
 392 {
 393         mutex_init(&mmpcam_devices_lock);
 394         return platform_driver_register(&mmpcam_driver);
 395 }
 396 
 397 static void __exit mmpcam_exit_module(void)
 398 {
 399         platform_driver_unregister(&mmpcam_driver);
 400         /*
 401          * platform_driver_unregister() should have emptied the list
 402          */
 403         if (!list_empty(&mmpcam_devices))
 404                 printk(KERN_ERR "mmp_camera leaving devices behind\n");
 405 }
 406 
 407 module_init(mmpcam_init_module);
 408 module_exit(mmpcam_exit_module);