drivers/net/can/cc770/cc770_platform.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Driver for CC770 and AN82527 CAN controllers on the platform bus
   4  *
   5  * Copyright (C) 2009, 2011 Wolfgang Grandegger <[email protected]>
   6  */
   7
   8 /*
   9  * If platform data are used you should have similar definitions
  10  * in your board-specific code:
  11  *
  12  *   static struct cc770_platform_data myboard_cc770_pdata = {
  13  *           .osc_freq = 16000000,
  14  *           .cir = 0x41,
  15  *           .cor = 0x20,
  16  *           .bcr = 0x40,
  17  *   };
  18  *
  19  * Please see include/linux/can/platform/cc770.h for description of
  20  * above fields.
  21  *
  22  * If the device tree is used, you need a CAN node definition in your
  23  * DTS file similar to:
  24  *
  25  *   can@3,100 {
  26  *           compatible = "bosch,cc770";
  27  *           reg = <3 0x100 0x80>;
  28  *           interrupts = <2 0>;
  29  *           interrupt-parent = <&mpic>;
  30  *           bosch,external-clock-frequency = <16000000>;
  31  *   };
  32  *
  33  * See "Documentation/devicetree/bindings/net/can/cc770.txt" for further
  34  * information.
  35  */
  36
  37 #include <linux/kernel.h>
  38 #include <linux/module.h>
  39 #include <linux/interrupt.h>
  40 #include <linux/netdevice.h>
  41 #include <linux/delay.h>
  42 #include <linux/platform_device.h>
  43 #include <linux/of.h>
  44 #include <linux/can.h>
  45 #include <linux/can/dev.h>
  46 #include <linux/can/platform/cc770.h>
  47
  48 #include "cc770.h"
  49
  50 #define DRV_NAME "cc770_platform"
  51
  52 MODULE_AUTHOR("Wolfgang Grandegger <[email protected]>");
  53 MODULE_DESCRIPTION("Socket-CAN driver for CC770 on the platform bus");
  54 MODULE_LICENSE("GPL v2");
  55 MODULE_ALIAS("platform:" DRV_NAME);
  56
  57 #define CC770_PLATFORM_CAN_CLOCK  16000000
  58
  59 static u8 cc770_platform_read_reg(const struct cc770_priv *priv, int reg)
  60 {
  61         return ioread8(priv->reg_base + reg);
  62 }
  63
  64 static void cc770_platform_write_reg(const struct cc770_priv *priv, int reg,
  65                                      u8 val)
  66 {
  67         iowrite8(val, priv->reg_base + reg);
  68 }
  69
  70 static int cc770_get_of_node_data(struct platform_device *pdev,
  71                                   struct cc770_priv *priv)
  72 {
  73         u32 clkext = CC770_PLATFORM_CAN_CLOCK, clkout = 0;
  74         struct device_node *np = pdev->dev.of_node;
  75
  76         of_property_read_u32(np, "bosch,external-clock-frequency", &clkext);
  77         priv->can.clock.freq = clkext;
  78
  79         /* The system clock may not exceed 10 MHz */
  80         if (priv->can.clock.freq > 10000000) {
  81                 priv->cpu_interface |= CPUIF_DSC;
  82                 priv->can.clock.freq /= 2;
  83         }
  84
  85         /* The memory clock may not exceed 8 MHz */
  86         if (priv->can.clock.freq > 8000000)
  87                 priv->cpu_interface |= CPUIF_DMC;
  88
  89         if (of_property_read_bool(np, "bosch,divide-memory-clock"))
  90                 priv->cpu_interface |= CPUIF_DMC;
  91         if (of_property_read_bool(np, "bosch,iso-low-speed-mux"))
  92                 priv->cpu_interface |= CPUIF_MUX;
  93
  94         if (!of_property_read_bool(np, "bosch,no-comperator-bypass"))
  95                 priv->bus_config |= BUSCFG_CBY;
  96         if (of_property_read_bool(np, "bosch,disconnect-rx0-input"))
  97                 priv->bus_config |= BUSCFG_DR0;
  98         if (of_property_read_bool(np, "bosch,disconnect-rx1-input"))
  99                 priv->bus_config |= BUSCFG_DR1;
 100         if (of_property_read_bool(np, "bosch,disconnect-tx1-output"))
 101                 priv->bus_config |= BUSCFG_DT1;
 102         if (of_property_read_bool(np, "bosch,polarity-dominant"))
 103                 priv->bus_config |= BUSCFG_POL;
 104
 105         of_property_read_u32(np, "bosch,clock-out-frequency", &clkout);
 106         if (clkout > 0) {
 107                 u32 cdv = clkext / clkout;
 108
 109                 if (cdv > 0 && cdv < 16) {
 110                         u32 slew;
 111
 112                         priv->cpu_interface |= CPUIF_CEN;
 113                         priv->clkout |= (cdv - 1) & CLKOUT_CD_MASK;
 114
 115                         if (of_property_read_u32(np, "bosch,slew-rate", &slew)) {
 116                                 /* Determine default slew rate */
 117                                 slew = (CLKOUT_SL_MASK >>
 118                                         CLKOUT_SL_SHIFT) -
 119                                         ((cdv * clkext - 1) / 8000000);
 120                                 if (slew > (CLKOUT_SL_MASK >> CLKOUT_SL_SHIFT))
 121                                         slew = 0;
 122                         }
 123                         priv->clkout |= (slew << CLKOUT_SL_SHIFT) &
 124                                 CLKOUT_SL_MASK;
 125                 } else {
 126                         dev_dbg(&pdev->dev, "invalid clock-out-frequency\n");
 127                 }
 128         }
 129
 130         return 0;
 131 }
 132
 133 static int cc770_get_platform_data(struct platform_device *pdev,
 134                                    struct cc770_priv *priv)
 135 {
 136
 137         struct cc770_platform_data *pdata = dev_get_platdata(&pdev->dev);
 138
 139         priv->can.clock.freq = pdata->osc_freq;
 140         if (priv->cpu_interface & CPUIF_DSC)
 141                 priv->can.clock.freq /= 2;
 142         priv->clkout = pdata->cor;
 143         priv->bus_config = pdata->bcr;
 144         priv->cpu_interface = pdata->cir;
 145
 146         return 0;
 147 }
 148
 149 static int cc770_platform_probe(struct platform_device *pdev)
 150 {
 151         struct net_device *dev;
 152         struct cc770_priv *priv;
 153         struct resource *mem;
 154         resource_size_t mem_size;
 155         void __iomem *base;
 156         int err, irq;
 157
 158         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 159         irq = platform_get_irq(pdev, 0);
 160         if (!mem || irq <= 0)
 161                 return -ENODEV;
 162
 163         mem_size = resource_size(mem);
 164         if (!request_mem_region(mem->start, mem_size, pdev->name))
 165                 return -EBUSY;
 166
 167         base = ioremap(mem->start, mem_size);
 168         if (!base) {
 169                 err = -ENOMEM;
 170                 goto exit_release_mem;
 171         }
 172
 173         dev = alloc_cc770dev(0);
 174         if (!dev) {
 175                 err = -ENOMEM;
 176                 goto exit_unmap_mem;
 177         }
 178
 179         dev->irq = irq;
 180         priv = netdev_priv(dev);
 181         priv->read_reg = cc770_platform_read_reg;
 182         priv->write_reg = cc770_platform_write_reg;
 183         priv->irq_flags = IRQF_SHARED;
 184         priv->reg_base = base;
 185
 186         if (pdev->dev.of_node)
 187                 err = cc770_get_of_node_data(pdev, priv);
 188         else if (dev_get_platdata(&pdev->dev))
 189                 err = cc770_get_platform_data(pdev, priv);
 190         else
 191                 err = -ENODEV;
 192         if (err)
 193                 goto exit_free_cc770;
 194
 195         dev_dbg(&pdev->dev,
 196                  "reg_base=0x%p irq=%d clock=%d cpu_interface=0x%02x "
 197                  "bus_config=0x%02x clkout=0x%02x\n",
 198                  priv->reg_base, dev->irq, priv->can.clock.freq,
 199                  priv->cpu_interface, priv->bus_config, priv->clkout);
 200
 201         platform_set_drvdata(pdev, dev);
 202         SET_NETDEV_DEV(dev, &pdev->dev);
 203
 204         err = register_cc770dev(dev);
 205         if (err) {
 206                 dev_err(&pdev->dev,
 207                         "couldn't register CC700 device (err=%d)\n", err);
 208                 goto exit_free_cc770;
 209         }
 210
 211         return 0;
 212
 213 exit_free_cc770:
 214         free_cc770dev(dev);
 215 exit_unmap_mem:
 216         iounmap(base);
 217 exit_release_mem:
 218         release_mem_region(mem->start, mem_size);
 219
 220         return err;
 221 }
 222
 223 static void cc770_platform_remove(struct platform_device *pdev)
 224 {
 225         struct net_device *dev = platform_get_drvdata(pdev);
 226         struct cc770_priv *priv = netdev_priv(dev);
 227         struct resource *mem;
 228
 229         unregister_cc770dev(dev);
 230         iounmap(priv->reg_base);
 231         free_cc770dev(dev);
 232
 233         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 234         release_mem_region(mem->start, resource_size(mem));
 235 }
 236
 237 static const struct of_device_id cc770_platform_table[] = {
 238         {.compatible = "bosch,cc770"}, /* CC770 from Bosch */
 239         {.compatible = "intc,82527"},  /* AN82527 from Intel CP */
 240         {},
 241 };
 242 MODULE_DEVICE_TABLE(of, cc770_platform_table);
 243
 244 static struct platform_driver cc770_platform_driver = {
 245         .driver = {
 246                 .name = DRV_NAME,
 247                 .of_match_table = cc770_platform_table,
 248         },
 249         .probe = cc770_platform_probe,
 250         .remove = cc770_platform_remove,
 251 };
 252
 253 module_platform_driver(cc770_platform_driver);