drivers/net/can/cc770/cc770_platform.c

   1 /*
   2  * Driver for CC770 and AN82527 CAN controllers on the platform bus
   3  *
   4  * Copyright (C) 2009, 2011 Wolfgang Grandegger <wg@grandegger.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the version 2 of the GNU General Public License
   8  * as published by the Free Software Foundation
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  */
  15
  16 /*
  17  * If platform data are used you should have similar definitions
  18  * in your board-specific code:
  19  *
  20  *   static struct cc770_platform_data myboard_cc770_pdata = {
  21  *           .osc_freq = 16000000,
  22  *           .cir = 0x41,
  23  *           .cor = 0x20,
  24  *           .bcr = 0x40,
  25  *   };
  26  *
  27  * Please see include/linux/can/platform/cc770.h for description of
  28  * above fields.
  29  *
  30  * If the device tree is used, you need a CAN node definition in your
  31  * DTS file similar to:
  32  *
  33  *   can@3,100 {
  34  *           compatible = "bosch,cc770";
  35  *           reg = <3 0x100 0x80>;
  36  *           interrupts = <2 0>;
  37  *           interrupt-parent = <&mpic>;
  38  *           bosch,external-clock-frequency = <16000000>;
  39  *   };
  40  *
  41  * See "Documentation/devicetree/bindings/net/can/cc770.txt" for further
  42  * information.
  43  */
  44
  45 #include <linux/kernel.h>
  46 #include <linux/module.h>
  47 #include <linux/interrupt.h>
  48 #include <linux/netdevice.h>
  49 #include <linux/delay.h>
  50 #include <linux/platform_device.h>
  51 #include <linux/of.h>
  52 #include <linux/can.h>
  53 #include <linux/can/dev.h>
  54 #include <linux/can/platform/cc770.h>
  55
  56 #include "cc770.h"
  57
  58 #define DRV_NAME "cc770_platform"
  59
  60 MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
  61 MODULE_DESCRIPTION("Socket-CAN driver for CC770 on the platform bus");
  62 MODULE_LICENSE("GPL v2");
  63
  64 #define CC770_PLATFORM_CAN_CLOCK  16000000
  65
  66 static u8 cc770_platform_read_reg(const struct cc770_priv *priv, int reg)
  67 {
  68         return ioread8(priv->reg_base + reg);
  69 }
  70
  71 static void cc770_platform_write_reg(const struct cc770_priv *priv, int reg,
  72                                      u8 val)
  73 {
  74         iowrite8(val, priv->reg_base + reg);
  75 }
  76
  77 static int __devinit cc770_get_of_node_data(struct platform_device *pdev,
  78                                             struct cc770_priv *priv)
  79 {
  80         struct device_node *np = pdev->dev.of_node;
  81         const u32 *prop;
  82         int prop_size;
  83         u32 clkext;
  84
  85         prop = of_get_property(np, "bosch,external-clock-frequency",
  86                                &prop_size);
  87         if (prop && (prop_size ==  sizeof(u32)))
  88                 clkext = *prop;
  89         else
  90                 clkext = CC770_PLATFORM_CAN_CLOCK; /* default */
  91         priv->can.clock.freq = clkext;
  92
  93         /* The system clock may not exceed 10 MHz */
  94         if (priv->can.clock.freq > 10000000) {
  95                 priv->cpu_interface |= CPUIF_DSC;
  96                 priv->can.clock.freq /= 2;
  97         }
  98
  99         /* The memory clock may not exceed 8 MHz */
 100         if (priv->can.clock.freq > 8000000)
 101                 priv->cpu_interface |= CPUIF_DMC;
 102
 103         if (of_get_property(np, "bosch,divide-memory-clock", NULL))
 104                 priv->cpu_interface |= CPUIF_DMC;
 105         if (of_get_property(np, "bosch,iso-low-speed-mux", NULL))
 106                 priv->cpu_interface |= CPUIF_MUX;
 107
 108         if (!of_get_property(np, "bosch,no-comperator-bypass", NULL))
 109                 priv->bus_config |= BUSCFG_CBY;
 110         if (of_get_property(np, "bosch,disconnect-rx0-input", NULL))
 111                 priv->bus_config |= BUSCFG_DR0;
 112         if (of_get_property(np, "bosch,disconnect-rx1-input", NULL))
 113                 priv->bus_config |= BUSCFG_DR1;
 114         if (of_get_property(np, "bosch,disconnect-tx1-output", NULL))
 115                 priv->bus_config |= BUSCFG_DT1;
 116         if (of_get_property(np, "bosch,polarity-dominant", NULL))
 117                 priv->bus_config |= BUSCFG_POL;
 118
 119         prop = of_get_property(np, "bosch,clock-out-frequency", &prop_size);
 120         if (prop && (prop_size == sizeof(u32)) && *prop > 0) {
 121                 u32 cdv = clkext / *prop;
 122                 int slew;
 123
 124                 if (cdv > 0 && cdv < 16) {
 125                         priv->cpu_interface |= CPUIF_CEN;
 126                         priv->clkout |= (cdv - 1) & CLKOUT_CD_MASK;
 127
 128                         prop = of_get_property(np, "bosch,slew-rate",
 129                                                &prop_size);
 130                         if (prop && (prop_size == sizeof(u32))) {
 131                                 slew = *prop;
 132                         } else {
 133                                 /* Determine default slew rate */
 134                                 slew = (CLKOUT_SL_MASK >>
 135                                         CLKOUT_SL_SHIFT) -
 136                                         ((cdv * clkext - 1) / 8000000);
 137                                 if (slew < 0)
 138                                         slew = 0;
 139                         }
 140                         priv->clkout |= (slew << CLKOUT_SL_SHIFT) &
 141                                 CLKOUT_SL_MASK;
 142                 } else {
 143                         dev_dbg(&pdev->dev, "invalid clock-out-frequency\n");
 144                 }
 145         }
 146
 147         return 0;
 148 }
 149
 150 static int __devinit cc770_get_platform_data(struct platform_device *pdev,
 151                                              struct cc770_priv *priv)
 152 {
 153
 154         struct cc770_platform_data *pdata = pdev->dev.platform_data;
 155
 156         priv->can.clock.freq = pdata->osc_freq;
 157         if (priv->cpu_interface | CPUIF_DSC)
 158                 priv->can.clock.freq /= 2;
 159         priv->clkout = pdata->cor;
 160         priv->bus_config = pdata->bcr;
 161         priv->cpu_interface = pdata->cir;
 162
 163         return 0;
 164 }
 165
 166 static int __devinit cc770_platform_probe(struct platform_device *pdev)
 167 {
 168         struct net_device *dev;
 169         struct cc770_priv *priv;
 170         struct resource *mem;
 171         resource_size_t mem_size;
 172         void __iomem *base;
 173         int err, irq;
 174
 175         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 176         irq = platform_get_irq(pdev, 0);
 177         if (!mem || irq <= 0)
 178                 return -ENODEV;
 179
 180         mem_size = resource_size(mem);
 181         if (!request_mem_region(mem->start, mem_size, pdev->name))
 182                 return -EBUSY;
 183
 184         base = ioremap(mem->start, mem_size);
 185         if (!base) {
 186                 err = -ENOMEM;
 187                 goto exit_release_mem;
 188         }
 189
 190         dev = alloc_cc770dev(0);
 191         if (!dev) {
 192                 err = -ENOMEM;
 193                 goto exit_unmap_mem;
 194         }
 195
 196         dev->irq = irq;
 197         priv = netdev_priv(dev);
 198         priv->read_reg = cc770_platform_read_reg;
 199         priv->write_reg = cc770_platform_write_reg;
 200         priv->irq_flags = IRQF_SHARED;
 201         priv->reg_base = base;
 202
 203         if (pdev->dev.of_node)
 204                 err = cc770_get_of_node_data(pdev, priv);
 205         else if (pdev->dev.platform_data)
 206                 err = cc770_get_platform_data(pdev, priv);
 207         else
 208                 err = -ENODEV;
 209         if (err)
 210                 goto exit_free_cc770;
 211
 212         dev_dbg(&pdev->dev,
 213                  "reg_base=0x%p irq=%d clock=%d cpu_interface=0x%02x "
 214                  "bus_config=0x%02x clkout=0x%02x\n",
 215                  priv->reg_base, dev->irq, priv->can.clock.freq,
 216                  priv->cpu_interface, priv->bus_config, priv->clkout);
 217
 218         dev_set_drvdata(&pdev->dev, dev);
 219         SET_NETDEV_DEV(dev, &pdev->dev);
 220
 221         err = register_cc770dev(dev);
 222         if (err) {
 223                 dev_err(&pdev->dev,
 224                         "couldn't register CC700 device (err=%d)\n", err);
 225                 goto exit_free_cc770;
 226         }
 227
 228         return 0;
 229
 230 exit_free_cc770:
 231         free_cc770dev(dev);
 232 exit_unmap_mem:
 233         iounmap(base);
 234 exit_release_mem:
 235         release_mem_region(mem->start, mem_size);
 236
 237         return err;
 238 }
 239
 240 static int __devexit cc770_platform_remove(struct platform_device *pdev)
 241 {
 242         struct net_device *dev = dev_get_drvdata(&pdev->dev);
 243         struct cc770_priv *priv = netdev_priv(dev);
 244         struct resource *mem;
 245
 246         unregister_cc770dev(dev);
 247         iounmap(priv->reg_base);
 248         free_cc770dev(dev);
 249
 250         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 251         release_mem_region(mem->start, resource_size(mem));
 252
 253         return 0;
 254 }
 255
 256 static struct of_device_id __devinitdata cc770_platform_table[] = {
 257         {.compatible = "bosch,cc770"}, /* CC770 from Bosch */
 258         {.compatible = "intc,82527"},  /* AN82527 from Intel CP */
 259         {},
 260 };
 261
 262 static struct platform_driver cc770_platform_driver = {
 263         .driver = {
 264                 .name = DRV_NAME,
 265                 .owner = THIS_MODULE,
 266                 .of_match_table = cc770_platform_table,
 267         },
 268         .probe = cc770_platform_probe,
 269         .remove = __devexit_p(cc770_platform_remove),
 270 };
 271
 272 module_platform_driver(cc770_platform_driver);