kernel/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 MODULE_ALIAS("platform:" DRV_NAME);
  64
  65 #define CC770_PLATFORM_CAN_CLOCK  16000000
  66
  67 static u8 cc770_platform_read_reg(const struct cc770_priv *priv, int reg)
  68 {
  69         return ioread8(priv->reg_base + reg);
  70 }
  71
  72 static void cc770_platform_write_reg(const struct cc770_priv *priv, int reg,
  73                                      u8 val)
  74 {
  75         iowrite8(val, priv->reg_base + reg);
  76 }
  77
  78 static int cc770_get_of_node_data(struct platform_device *pdev,
  79                                   struct cc770_priv *priv)
  80 {
  81         struct device_node *np = pdev->dev.of_node;
  82         const u32 *prop;
  83         int prop_size;
  84         u32 clkext;
  85
  86         prop = of_get_property(np, "bosch,external-clock-frequency",
  87                                &prop_size);
  88         if (prop && (prop_size ==  sizeof(u32)))
  89                 clkext = *prop;
  90         else
  91                 clkext = CC770_PLATFORM_CAN_CLOCK; /* default */
  92         priv->can.clock.freq = clkext;
  93
  94         /* The system clock may not exceed 10 MHz */
  95         if (priv->can.clock.freq > 10000000) {
  96                 priv->cpu_interface |= CPUIF_DSC;
  97                 priv->can.clock.freq /= 2;
  98         }
  99
 100         /* The memory clock may not exceed 8 MHz */
 101         if (priv->can.clock.freq > 8000000)
 102                 priv->cpu_interface |= CPUIF_DMC;
 103
 104         if (of_get_property(np, "bosch,divide-memory-clock", NULL))
 105                 priv->cpu_interface |= CPUIF_DMC;
 106         if (of_get_property(np, "bosch,iso-low-speed-mux", NULL))
 107                 priv->cpu_interface |= CPUIF_MUX;
 108
 109         if (!of_get_property(np, "bosch,no-comperator-bypass", NULL))
 110                 priv->bus_config |= BUSCFG_CBY;
 111         if (of_get_property(np, "bosch,disconnect-rx0-input", NULL))
 112                 priv->bus_config |= BUSCFG_DR0;
 113         if (of_get_property(np, "bosch,disconnect-rx1-input", NULL))
 114                 priv->bus_config |= BUSCFG_DR1;
 115         if (of_get_property(np, "bosch,disconnect-tx1-output", NULL))
 116                 priv->bus_config |= BUSCFG_DT1;
 117         if (of_get_property(np, "bosch,polarity-dominant", NULL))
 118                 priv->bus_config |= BUSCFG_POL;
 119
 120         prop = of_get_property(np, "bosch,clock-out-frequency", &prop_size);
 121         if (prop && (prop_size == sizeof(u32)) && *prop > 0) {
 122                 u32 cdv = clkext / *prop;
 123                 int slew;
 124
 125                 if (cdv > 0 && cdv < 16) {
 126                         priv->cpu_interface |= CPUIF_CEN;
 127                         priv->clkout |= (cdv - 1) & CLKOUT_CD_MASK;
 128
 129                         prop = of_get_property(np, "bosch,slew-rate",
 130                                                &prop_size);
 131                         if (prop && (prop_size == sizeof(u32))) {
 132                                 slew = *prop;
 133                         } else {
 134                                 /* Determine default slew rate */
 135                                 slew = (CLKOUT_SL_MASK >>
 136                                         CLKOUT_SL_SHIFT) -
 137                                         ((cdv * clkext - 1) / 8000000);
 138                                 if (slew < 0)
 139                                         slew = 0;
 140                         }
 141                         priv->clkout |= (slew << CLKOUT_SL_SHIFT) &
 142                                 CLKOUT_SL_MASK;
 143                 } else {
 144                         dev_dbg(&pdev->dev, "invalid clock-out-frequency\n");
 145                 }
 146         }
 147
 148         return 0;
 149 }
 150
 151 static int cc770_get_platform_data(struct platform_device *pdev,
 152                                    struct cc770_priv *priv)
 153 {
 154
 155         struct cc770_platform_data *pdata = dev_get_platdata(&pdev->dev);
 156
 157         priv->can.clock.freq = pdata->osc_freq;
 158         if (priv->cpu_interface & CPUIF_DSC)
 159                 priv->can.clock.freq /= 2;
 160         priv->clkout = pdata->cor;
 161         priv->bus_config = pdata->bcr;
 162         priv->cpu_interface = pdata->cir;
 163
 164         return 0;
 165 }
 166
 167 static int cc770_platform_probe(struct platform_device *pdev)
 168 {
 169         struct net_device *dev;
 170         struct cc770_priv *priv;
 171         struct resource *mem;
 172         resource_size_t mem_size;
 173         void __iomem *base;
 174         int err, irq;
 175
 176         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 177         irq = platform_get_irq(pdev, 0);
 178         if (!mem || irq <= 0)
 179                 return -ENODEV;
 180
 181         mem_size = resource_size(mem);
 182         if (!request_mem_region(mem->start, mem_size, pdev->name))
 183                 return -EBUSY;
 184
 185         base = ioremap(mem->start, mem_size);
 186         if (!base) {
 187                 err = -ENOMEM;
 188                 goto exit_release_mem;
 189         }
 190
 191         dev = alloc_cc770dev(0);
 192         if (!dev) {
 193                 err = -ENOMEM;
 194                 goto exit_unmap_mem;
 195         }
 196
 197         dev->irq = irq;
 198         priv = netdev_priv(dev);
 199         priv->read_reg = cc770_platform_read_reg;
 200         priv->write_reg = cc770_platform_write_reg;
 201         priv->irq_flags = IRQF_SHARED;
 202         priv->reg_base = base;
 203
 204         if (pdev->dev.of_node)
 205                 err = cc770_get_of_node_data(pdev, priv);
 206         else if (dev_get_platdata(&pdev->dev))
 207                 err = cc770_get_platform_data(pdev, priv);
 208         else
 209                 err = -ENODEV;
 210         if (err)
 211                 goto exit_free_cc770;
 212
 213         dev_dbg(&pdev->dev,
 214                  "reg_base=0x%p irq=%d clock=%d cpu_interface=0x%02x "
 215                  "bus_config=0x%02x clkout=0x%02x\n",
 216                  priv->reg_base, dev->irq, priv->can.clock.freq,
 217                  priv->cpu_interface, priv->bus_config, priv->clkout);
 218
 219         platform_set_drvdata(pdev, dev);
 220         SET_NETDEV_DEV(dev, &pdev->dev);
 221
 222         err = register_cc770dev(dev);
 223         if (err) {
 224                 dev_err(&pdev->dev,
 225                         "couldn't register CC700 device (err=%d)\n", err);
 226                 goto exit_free_cc770;
 227         }
 228
 229         return 0;
 230
 231 exit_free_cc770:
 232         free_cc770dev(dev);
 233 exit_unmap_mem:
 234         iounmap(base);
 235 exit_release_mem:
 236         release_mem_region(mem->start, mem_size);
 237
 238         return err;
 239 }
 240
 241 static int cc770_platform_remove(struct platform_device *pdev)
 242 {
 243         struct net_device *dev = platform_get_drvdata(pdev);
 244         struct cc770_priv *priv = netdev_priv(dev);
 245         struct resource *mem;
 246
 247         unregister_cc770dev(dev);
 248         iounmap(priv->reg_base);
 249         free_cc770dev(dev);
 250
 251         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 252         release_mem_region(mem->start, resource_size(mem));
 253
 254         return 0;
 255 }
 256
 257 static const struct of_device_id cc770_platform_table[] = {
 258         {.compatible = "bosch,cc770"}, /* CC770 from Bosch */
 259         {.compatible = "intc,82527"},  /* AN82527 from Intel CP */
 260         {},
 261 };
 262 MODULE_DEVICE_TABLE(of, cc770_platform_table);
 263
 264 static struct platform_driver cc770_platform_driver = {
 265         .driver = {
 266                 .name = DRV_NAME,
 267                 .of_match_table = cc770_platform_table,
 268         },
 269         .probe = cc770_platform_probe,
 270         .remove = cc770_platform_remove,
 271 };
 272
 273 module_platform_driver(cc770_platform_driver);