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 #include <linux/pinctrl/consumer.h>
  36
  37 #include <linux/can/dev.h>
  38
  39 #include "c_can.h"
  40
  41 #define CAN_RAMINIT_START_MASK(i)       (1 << (i))
  42
  43 /*
  44  * 16-bit c_can registers can be arranged differently in the memory
  45  * architecture of different implementations. For example: 16-bit
  46  * registers can be aligned to a 16-bit boundary or 32-bit boundary etc.
  47  * Handle the same by providing a common read/write interface.
  48  */
  49 static u16 c_can_plat_read_reg_aligned_to_16bit(struct c_can_priv *priv,
  50                                                 enum reg index)
  51 {
  52         return readw(priv->base + priv->regs[index]);
  53 }
  54
  55 static void c_can_plat_write_reg_aligned_to_16bit(struct c_can_priv *priv,
  56                                                 enum reg index, u16 val)
  57 {
  58         writew(val, priv->base + priv->regs[index]);
  59 }
  60
  61 static u16 c_can_plat_read_reg_aligned_to_32bit(struct c_can_priv *priv,
  62                                                 enum reg index)
  63 {
  64         return readw(priv->base + 2 * priv->regs[index]);
  65 }
  66
  67 static void c_can_plat_write_reg_aligned_to_32bit(struct c_can_priv *priv,
  68                                                 enum reg index, u16 val)
  69 {
  70         writew(val, priv->base + 2 * priv->regs[index]);
  71 }
  72
  73 static void c_can_hw_raminit(const struct c_can_priv *priv, bool enable)
  74 {
  75         u32 val;
  76
  77         val = readl(priv->raminit_ctrlreg);
  78         if (enable)
  79                 val |= CAN_RAMINIT_START_MASK(priv->instance);
  80         else
  81                 val &= ~CAN_RAMINIT_START_MASK(priv->instance);
  82         writel(val, priv->raminit_ctrlreg);
  83 }
  84
  85 static struct platform_device_id c_can_id_table[] = {
  86         [BOSCH_C_CAN_PLATFORM] = {
  87                 .name = KBUILD_MODNAME,
  88                 .driver_data = BOSCH_C_CAN,
  89         },
  90         [BOSCH_C_CAN] = {
  91                 .name = "c_can",
  92                 .driver_data = BOSCH_C_CAN,
  93         },
  94         [BOSCH_D_CAN] = {
  95                 .name = "d_can",
  96                 .driver_data = BOSCH_D_CAN,
  97         }, {
  98         }
  99 };
 100 MODULE_DEVICE_TABLE(platform, c_can_id_table);
 101
 102 static const struct of_device_id c_can_of_table[] = {
 103         { .compatible = "bosch,c_can", .data = &c_can_id_table[BOSCH_C_CAN] },
 104         { .compatible = "bosch,d_can", .data = &c_can_id_table[BOSCH_D_CAN] },
 105         { /* sentinel */ },
 106 };
 107 MODULE_DEVICE_TABLE(of, c_can_of_table);
 108
 109 static int c_can_plat_probe(struct platform_device *pdev)
 110 {
 111         int ret;
 112         void __iomem *addr;
 113         struct net_device *dev;
 114         struct c_can_priv *priv;
 115         const struct of_device_id *match;
 116         const struct platform_device_id *id;
 117         struct pinctrl *pinctrl;
 118         struct resource *mem, *res;
 119         int irq;
 120         struct clk *clk;
 121
 122         if (pdev->dev.of_node) {
 123                 match = of_match_device(c_can_of_table, &pdev->dev);
 124                 if (!match) {
 125                         dev_err(&pdev->dev, "Failed to find matching dt id\n");
 126                         ret = -EINVAL;
 127                         goto exit;
 128                 }
 129                 id = match->data;
 130         } else {
 131                 id = platform_get_device_id(pdev);
 132         }
 133
 134         pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
 135         if (IS_ERR(pinctrl))
 136                 dev_warn(&pdev->dev,
 137                         "failed to configure pins from driver\n");
 138
 139         /* get the appropriate clk */
 140         clk = clk_get(&pdev->dev, NULL);
 141         if (IS_ERR(clk)) {
 142                 dev_err(&pdev->dev, "no clock defined\n");
 143                 ret = -ENODEV;
 144                 goto exit;
 145         }
 146
 147         /* get the platform data */
 148         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 149         irq = platform_get_irq(pdev, 0);
 150         if (!mem || irq <= 0) {
 151                 ret = -ENODEV;
 152                 goto exit_free_clk;
 153         }
 154
 155         if (!request_mem_region(mem->start, resource_size(mem),
 156                                 KBUILD_MODNAME)) {
 157                 dev_err(&pdev->dev, "resource unavailable\n");
 158                 ret = -ENODEV;
 159                 goto exit_free_clk;
 160         }
 161
 162         addr = ioremap(mem->start, resource_size(mem));
 163         if (!addr) {
 164                 dev_err(&pdev->dev, "failed to map can port\n");
 165                 ret = -ENOMEM;
 166                 goto exit_release_mem;
 167         }
 168
 169         /* allocate the c_can device */
 170         dev = alloc_c_can_dev();
 171         if (!dev) {
 172                 ret = -ENOMEM;
 173                 goto exit_iounmap;
 174         }
 175
 176         priv = netdev_priv(dev);
 177         switch (id->driver_data) {
 178         case BOSCH_C_CAN:
 179                 priv->regs = reg_map_c_can;
 180                 switch (mem->flags & IORESOURCE_MEM_TYPE_MASK) {
 181                 case IORESOURCE_MEM_32BIT:
 182                         priv->read_reg = c_can_plat_read_reg_aligned_to_32bit;
 183                         priv->write_reg = c_can_plat_write_reg_aligned_to_32bit;
 184                         break;
 185                 case IORESOURCE_MEM_16BIT:
 186                 default:
 187                         priv->read_reg = c_can_plat_read_reg_aligned_to_16bit;
 188                         priv->write_reg = c_can_plat_write_reg_aligned_to_16bit;
 189                         break;
 190                 }
 191                 break;
 192         case BOSCH_D_CAN:
 193                 priv->regs = reg_map_d_can;
 194                 priv->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES;
 195                 priv->read_reg = c_can_plat_read_reg_aligned_to_16bit;
 196                 priv->write_reg = c_can_plat_write_reg_aligned_to_16bit;
 197
 198                 if (pdev->dev.of_node)
 199                         priv->instance = of_alias_get_id(pdev->dev.of_node, "d_can");
 200                 else
 201                         priv->instance = pdev->id;
 202
 203                 res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 204                 priv->raminit_ctrlreg = devm_ioremap_resource(&pdev->dev, res);
 205                 if (IS_ERR(priv->raminit_ctrlreg) || priv->instance < 0)
 206                         dev_info(&pdev->dev, "control memory is not used for raminit\n");
 207                 else
 208                         priv->raminit = c_can_hw_raminit;
 209                 break;
 210         default:
 211                 ret = -EINVAL;
 212                 goto exit_free_device;
 213         }
 214
 215         dev->irq = irq;
 216         priv->base = addr;
 217         priv->device = &pdev->dev;
 218         priv->can.clock.freq = clk_get_rate(clk);
 219         priv->priv = clk;
 220         priv->type = id->driver_data;
 221
 222         platform_set_drvdata(pdev, dev);
 223         SET_NETDEV_DEV(dev, &pdev->dev);
 224
 225         ret = register_c_can_dev(dev);
 226         if (ret) {
 227                 dev_err(&pdev->dev, "registering %s failed (err=%d)\n",
 228                         KBUILD_MODNAME, ret);
 229                 goto exit_free_device;
 230         }
 231
 232         dev_info(&pdev->dev, "%s device registered (regs=%p, irq=%d)\n",
 233                  KBUILD_MODNAME, priv->base, dev->irq);
 234         return 0;
 235
 236 exit_free_device:
 237         free_c_can_dev(dev);
 238 exit_iounmap:
 239         iounmap(addr);
 240 exit_release_mem:
 241         release_mem_region(mem->start, resource_size(mem));
 242 exit_free_clk:
 243         clk_put(clk);
 244 exit:
 245         dev_err(&pdev->dev, "probe failed\n");
 246
 247         return ret;
 248 }
 249
 250 static int c_can_plat_remove(struct platform_device *pdev)
 251 {
 252         struct net_device *dev = platform_get_drvdata(pdev);
 253         struct c_can_priv *priv = netdev_priv(dev);
 254         struct resource *mem;
 255
 256         unregister_c_can_dev(dev);
 257
 258         free_c_can_dev(dev);
 259         iounmap(priv->base);
 260
 261         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 262         release_mem_region(mem->start, resource_size(mem));
 263
 264         clk_put(priv->priv);
 265
 266         return 0;
 267 }
 268
 269 #ifdef CONFIG_PM
 270 static int c_can_suspend(struct platform_device *pdev, pm_message_t state)
 271 {
 272         int ret;
 273         struct net_device *ndev = platform_get_drvdata(pdev);
 274         struct c_can_priv *priv = netdev_priv(ndev);
 275
 276         if (priv->type != BOSCH_D_CAN) {
 277                 dev_warn(&pdev->dev, "Not supported\n");
 278                 return 0;
 279         }
 280
 281         if (netif_running(ndev)) {
 282                 netif_stop_queue(ndev);
 283                 netif_device_detach(ndev);
 284         }
 285
 286         ret = c_can_power_down(ndev);
 287         if (ret) {
 288                 netdev_err(ndev, "failed to enter power down mode\n");
 289                 return ret;
 290         }
 291
 292         priv->can.state = CAN_STATE_SLEEPING;
 293
 294         return 0;
 295 }
 296
 297 static int c_can_resume(struct platform_device *pdev)
 298 {
 299         int ret;
 300         struct net_device *ndev = platform_get_drvdata(pdev);
 301         struct c_can_priv *priv = netdev_priv(ndev);
 302
 303         if (priv->type != BOSCH_D_CAN) {
 304                 dev_warn(&pdev->dev, "Not supported\n");
 305                 return 0;
 306         }
 307
 308         ret = c_can_power_up(ndev);
 309         if (ret) {
 310                 netdev_err(ndev, "Still in power down mode\n");
 311                 return ret;
 312         }
 313
 314         priv->can.state = CAN_STATE_ERROR_ACTIVE;
 315
 316         if (netif_running(ndev)) {
 317                 netif_device_attach(ndev);
 318                 netif_start_queue(ndev);
 319         }
 320
 321         return 0;
 322 }
 323 #else
 324 #define c_can_suspend NULL
 325 #define c_can_resume NULL
 326 #endif
 327
 328 static struct platform_driver c_can_plat_driver = {
 329         .driver = {
 330                 .name = KBUILD_MODNAME,
 331                 .owner = THIS_MODULE,
 332                 .of_match_table = of_match_ptr(c_can_of_table),
 333         },
 334         .probe = c_can_plat_probe,
 335         .remove = c_can_plat_remove,
 336         .suspend = c_can_suspend,
 337         .resume = c_can_resume,
 338         .id_table = c_can_id_table,
 339 };
 340
 341 module_platform_driver(c_can_plat_driver);
 342
 343 MODULE_AUTHOR("Bhupesh Sharma <bhupesh.sharma@st.com>");
 344 MODULE_LICENSE("GPL v2");
 345 MODULE_DESCRIPTION("Platform CAN bus driver for Bosch C_CAN controller");