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