drivers/net/can/c_can/c_can_platform.c

   1 /*
   2  * Platform CAN bus driver for Bosch C_CAN controller
   3  *
   4  * Copyright (C) 2010 ST Microelectronics
   5  * Bhupesh Sharma <bhupesh.sharma@st.com>
   6  *
   7  * Borrowed heavily from the C_CAN driver originally written by:
   8  * Copyright (C) 2007
   9  * - Sascha Hauer, Marc Kleine-Budde, Pengutronix <s.hauer@pengutronix.de>
  10  * - Simon Kallweit, intefo AG <simon.kallweit@intefo.ch>
  11  *
  12  * Bosch C_CAN controller is compliant to CAN protocol version 2.0 part A and B.
  13  * Bosch C_CAN user manual can be obtained from:
  14  * http://www.semiconductors.bosch.de/media/en/pdf/ipmodules_1/c_can/
  15  * users_manual_c_can.pdf
  16  *
  17  * This file is licensed under the terms of the GNU General Public
  18  * License version 2. This program is licensed "as is" without any
  19  * warranty of any kind, whether express or implied.
  20  */
  21
  22 #include <linux/kernel.h>
  23 #include <linux/module.h>
  24 #include <linux/interrupt.h>
  25 #include <linux/delay.h>
  26 #include <linux/netdevice.h>
  27 #include <linux/if_arp.h>
  28 #include <linux/if_ether.h>
  29 #include <linux/list.h>
  30 #include <linux/io.h>
  31 #include <linux/platform_device.h>
  32 #include <linux/clk.h>
  33 #include <linux/of.h>
  34 #include <linux/of_device.h>
  35
  36 #include <linux/can/dev.h>
  37
  38 #include "c_can.h"
  39
  40 #define CAN_RAMINIT_START_MASK(i)       (0x001 << (i))
  41 #define CAN_RAMINIT_DONE_MASK(i)        (0x100 << (i))
  42 #define CAN_RAMINIT_ALL_MASK(i)         (0x101 << (i))
  43 static DEFINE_SPINLOCK(raminit_lock);
  44 /*
  45  * 16-bit c_can registers can be arranged differently in the memory
  46  * architecture of different implementations. For example: 16-bit
  47  * registers can be aligned to a 16-bit boundary or 32-bit boundary etc.
  48  * Handle the same by providing a common read/write interface.
  49  */
  50 static u16 c_can_plat_read_reg_aligned_to_16bit(struct c_can_priv *priv,
  51                                                 enum reg index)
  52 {
  53         return readw(priv->base + priv->regs[index]);
  54 }
  55
  56 static void c_can_plat_write_reg_aligned_to_16bit(struct c_can_priv *priv,
  57                                                 enum reg index, u16 val)
  58 {
  59         writew(val, priv->base + priv->regs[index]);
  60 }
  61
  62 static u16 c_can_plat_read_reg_aligned_to_32bit(struct c_can_priv *priv,
  63                                                 enum reg index)
  64 {
  65         return readw(priv->base + 2 * priv->regs[index]);
  66 }
  67
  68 static void c_can_plat_write_reg_aligned_to_32bit(struct c_can_priv *priv,
  69                                                 enum reg index, u16 val)
  70 {
  71         writew(val, priv->base + 2 * priv->regs[index]);
  72 }
  73
  74 static void c_can_hw_raminit_wait(const struct c_can_priv *priv, u32 mask,
  75                                   u32 val)
  76 {
  77         /* We look only at the bits of our instance. */
  78         val &= mask;
  79         while ((readl(priv->raminit_ctrlreg) & mask) != val)
  80                 udelay(1);
  81 }
  82
  83 static void c_can_hw_raminit(const struct c_can_priv *priv, bool enable)
  84 {
  85         u32 mask = CAN_RAMINIT_ALL_MASK(priv->instance);
  86         u32 ctrl;
  87
  88         spin_lock(&raminit_lock);
  89
  90         ctrl = readl(priv->raminit_ctrlreg);
  91         /* We clear the done and start bit first. The start bit is
  92          * looking at the 0 -> transition, but is not self clearing;
  93          * And we clear the init done bit as well.
  94          */
  95         ctrl &= ~CAN_RAMINIT_START_MASK(priv->instance);
  96         ctrl |= CAN_RAMINIT_DONE_MASK(priv->instance);
  97         writel(ctrl, priv->raminit_ctrlreg);
  98         ctrl &= ~CAN_RAMINIT_DONE_MASK(priv->instance);
  99         c_can_hw_raminit_wait(priv, ctrl, mask);
 100
 101         if (enable) {
 102                 /* Set start bit and wait for the done bit. */
 103                 ctrl |= CAN_RAMINIT_START_MASK(priv->instance);
 104                 writel(ctrl, priv->raminit_ctrlreg);
 105                 ctrl |= CAN_RAMINIT_DONE_MASK(priv->instance);
 106                 c_can_hw_raminit_wait(priv, ctrl, mask);
 107         }
 108         spin_unlock(&raminit_lock);
 109 }
 110
 111 static struct platform_device_id c_can_id_table[] = {
 112         [BOSCH_C_CAN_PLATFORM] = {
 113                 .name = KBUILD_MODNAME,
 114                 .driver_data = BOSCH_C_CAN,
 115         },
 116         [BOSCH_C_CAN] = {
 117                 .name = "c_can",
 118                 .driver_data = BOSCH_C_CAN,
 119         },
 120         [BOSCH_D_CAN] = {
 121                 .name = "d_can",
 122                 .driver_data = BOSCH_D_CAN,
 123         }, {
 124         }
 125 };
 126 MODULE_DEVICE_TABLE(platform, c_can_id_table);
 127
 128 static const struct of_device_id c_can_of_table[] = {
 129         { .compatible = "bosch,c_can", .data = &c_can_id_table[BOSCH_C_CAN] },
 130         { .compatible = "bosch,d_can", .data = &c_can_id_table[BOSCH_D_CAN] },
 131         { /* sentinel */ },
 132 };
 133 MODULE_DEVICE_TABLE(of, c_can_of_table);
 134
 135 static int c_can_plat_probe(struct platform_device *pdev)
 136 {
 137         int ret;
 138         void __iomem *addr;
 139         struct net_device *dev;
 140         struct c_can_priv *priv;
 141         const struct of_device_id *match;
 142         const struct platform_device_id *id;
 143         struct resource *mem, *res;
 144         int irq;
 145         struct clk *clk;
 146
 147         if (pdev->dev.of_node) {
 148                 match = of_match_device(c_can_of_table, &pdev->dev);
 149                 if (!match) {
 150                         dev_err(&pdev->dev, "Failed to find matching dt id\n");
 151                         ret = -EINVAL;
 152                         goto exit;
 153                 }
 154                 id = match->data;
 155         } else {
 156                 id = platform_get_device_id(pdev);
 157         }
 158
 159         /* get the appropriate clk */
 160         clk = clk_get(&pdev->dev, NULL);
 161         if (IS_ERR(clk)) {
 162                 dev_err(&pdev->dev, "no clock defined\n");
 163                 ret = -ENODEV;
 164                 goto exit;
 165         }
 166
 167         /* get the platform data */
 168         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 169         irq = platform_get_irq(pdev, 0);
 170         if (!mem || irq <= 0) {
 171                 ret = -ENODEV;
 172                 goto exit_free_clk;
 173         }
 174
 175         if (!request_mem_region(mem->start, resource_size(mem),
 176                                 KBUILD_MODNAME)) {
 177                 dev_err(&pdev->dev, "resource unavailable\n");
 178                 ret = -ENODEV;
 179                 goto exit_free_clk;
 180         }
 181
 182         addr = ioremap(mem->start, resource_size(mem));
 183         if (!addr) {
 184                 dev_err(&pdev->dev, "failed to map can port\n");
 185                 ret = -ENOMEM;
 186                 goto exit_release_mem;
 187         }
 188
 189         /* allocate the c_can device */
 190         dev = alloc_c_can_dev();
 191         if (!dev) {
 192                 ret = -ENOMEM;
 193                 goto exit_iounmap;
 194         }
 195
 196         priv = netdev_priv(dev);
 197         switch (id->driver_data) {
 198         case BOSCH_C_CAN:
 199                 priv->regs = reg_map_c_can;
 200                 switch (mem->flags & IORESOURCE_MEM_TYPE_MASK) {
 201                 case IORESOURCE_MEM_32BIT:
 202                         priv->read_reg = c_can_plat_read_reg_aligned_to_32bit;
 203                         priv->write_reg = c_can_plat_write_reg_aligned_to_32bit;
 204                         break;
 205                 case IORESOURCE_MEM_16BIT:
 206                 default:
 207                         priv->read_reg = c_can_plat_read_reg_aligned_to_16bit;
 208                         priv->write_reg = c_can_plat_write_reg_aligned_to_16bit;
 209                         break;
 210                 }
 211                 break;
 212         case BOSCH_D_CAN:
 213                 priv->regs = reg_map_d_can;
 214                 priv->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES;
 215                 priv->read_reg = c_can_plat_read_reg_aligned_to_16bit;
 216                 priv->write_reg = c_can_plat_write_reg_aligned_to_16bit;
 217
 218                 if (pdev->dev.of_node)
 219                         priv->instance = of_alias_get_id(pdev->dev.of_node, "d_can");
 220                 else
 221                         priv->instance = pdev->id;
 222
 223                 res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 224                 priv->raminit_ctrlreg = devm_ioremap_resource(&pdev->dev, res);
 225                 if (IS_ERR(priv->raminit_ctrlreg) || (int)priv->instance < 0)
 226                         dev_info(&pdev->dev, "control memory is not used for raminit\n");
 227                 else
 228                         priv->raminit = c_can_hw_raminit;
 229                 break;
 230         default:
 231                 ret = -EINVAL;
 232                 goto exit_free_device;
 233         }
 234
 235         dev->irq = irq;
 236         priv->base = addr;
 237         priv->device = &pdev->dev;
 238         priv->can.clock.freq = clk_get_rate(clk);
 239         priv->priv = clk;
 240         priv->type = id->driver_data;
 241
 242         platform_set_drvdata(pdev, dev);
 243         SET_NETDEV_DEV(dev, &pdev->dev);
 244
 245         ret = register_c_can_dev(dev);
 246         if (ret) {
 247                 dev_err(&pdev->dev, "registering %s failed (err=%d)\n",
 248                         KBUILD_MODNAME, ret);
 249                 goto exit_free_device;
 250         }
 251
 252         dev_info(&pdev->dev, "%s device registered (regs=%p, irq=%d)\n",
 253                  KBUILD_MODNAME, priv->base, dev->irq);
 254         return 0;
 255
 256 exit_free_device:
 257         free_c_can_dev(dev);
 258 exit_iounmap:
 259         iounmap(addr);
 260 exit_release_mem:
 261         release_mem_region(mem->start, resource_size(mem));
 262 exit_free_clk:
 263         clk_put(clk);
 264 exit:
 265         dev_err(&pdev->dev, "probe failed\n");
 266
 267         return ret;
 268 }
 269
 270 static int c_can_plat_remove(struct platform_device *pdev)
 271 {
 272         struct net_device *dev = platform_get_drvdata(pdev);
 273         struct c_can_priv *priv = netdev_priv(dev);
 274         struct resource *mem;
 275
 276         unregister_c_can_dev(dev);
 277
 278         free_c_can_dev(dev);
 279         iounmap(priv->base);
 280
 281         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 282         release_mem_region(mem->start, resource_size(mem));
 283
 284         clk_put(priv->priv);
 285
 286         return 0;
 287 }
 288
 289 #ifdef CONFIG_PM
 290 static int c_can_suspend(struct platform_device *pdev, pm_message_t state)
 291 {
 292         int ret;
 293         struct net_device *ndev = platform_get_drvdata(pdev);
 294         struct c_can_priv *priv = netdev_priv(ndev);
 295
 296         if (priv->type != BOSCH_D_CAN) {
 297                 dev_warn(&pdev->dev, "Not supported\n");
 298                 return 0;
 299         }
 300
 301         if (netif_running(ndev)) {
 302                 netif_stop_queue(ndev);
 303                 netif_device_detach(ndev);
 304         }
 305
 306         ret = c_can_power_down(ndev);
 307         if (ret) {
 308                 netdev_err(ndev, "failed to enter power down mode\n");
 309                 return ret;
 310         }
 311
 312         priv->can.state = CAN_STATE_SLEEPING;
 313
 314         return 0;
 315 }
 316
 317 static int c_can_resume(struct platform_device *pdev)
 318 {
 319         int ret;
 320         struct net_device *ndev = platform_get_drvdata(pdev);
 321         struct c_can_priv *priv = netdev_priv(ndev);
 322
 323         if (priv->type != BOSCH_D_CAN) {
 324                 dev_warn(&pdev->dev, "Not supported\n");
 325                 return 0;
 326         }
 327
 328         ret = c_can_power_up(ndev);
 329         if (ret) {
 330                 netdev_err(ndev, "Still in power down mode\n");
 331                 return ret;
 332         }
 333
 334         priv->can.state = CAN_STATE_ERROR_ACTIVE;
 335
 336         if (netif_running(ndev)) {
 337                 netif_device_attach(ndev);
 338                 netif_start_queue(ndev);
 339         }
 340
 341         return 0;
 342 }
 343 #else
 344 #define c_can_suspend NULL
 345 #define c_can_resume NULL
 346 #endif
 347
 348 static struct platform_driver c_can_plat_driver = {
 349         .driver = {
 350                 .name = KBUILD_MODNAME,
 351                 .owner = THIS_MODULE,
 352                 .of_match_table = c_can_of_table,
 353         },
 354         .probe = c_can_plat_probe,
 355         .remove = c_can_plat_remove,
 356         .suspend = c_can_suspend,
 357         .resume = c_can_resume,
 358         .id_table = c_can_id_table,
 359 };
 360
 361 module_platform_driver(c_can_plat_driver);
 362
 363 MODULE_AUTHOR("Bhupesh Sharma <bhupesh.sharma@st.com>");
 364 MODULE_LICENSE("GPL v2");
 365 MODULE_DESCRIPTION("Platform CAN bus driver for Bosch C_CAN controller");