can/cc770/cc770_platform.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * Driver for CC770 and AN82527 CAN controllers on the platform bus
0004  *
0005  * Copyright (C) 2009, 2011 Wolfgang Grandegger <wg@grandegger.com>
0006  */
0007
0008 /*
0009  * If platform data are used you should have similar definitions
0010  * in your board-specific code:
0011  *
0012  *   static struct cc770_platform_data myboard_cc770_pdata = {
0013  *           .osc_freq = 16000000,
0014  *           .cir = 0x41,
0015  *           .cor = 0x20,
0016  *           .bcr = 0x40,
0017  *   };
0018  *
0019  * Please see include/linux/can/platform/cc770.h for description of
0020  * above fields.
0021  *
0022  * If the device tree is used, you need a CAN node definition in your
0023  * DTS file similar to:
0024  *
0025  *   can@3,100 {
0026  *           compatible = "bosch,cc770";
0027  *           reg = <3 0x100 0x80>;
0028  *           interrupts = <2 0>;
0029  *           interrupt-parent = <&mpic>;
0030  *           bosch,external-clock-frequency = <16000000>;
0031  *   };
0032  *
0033  * See "Documentation/devicetree/bindings/net/can/cc770.txt" for further
0034  * information.
0035  */
0036
0037 #include <linux/kernel.h>
0038 #include <linux/module.h>
0039 #include <linux/interrupt.h>
0040 #include <linux/netdevice.h>
0041 #include <linux/delay.h>
0042 #include <linux/platform_device.h>
0043 #include <linux/of.h>
0044 #include <linux/can.h>
0045 #include <linux/can/dev.h>
0046 #include <linux/can/platform/cc770.h>
0047
0048 #include "cc770.h"
0049
0050 #define DRV_NAME "cc770_platform"
0051
0052 MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
0053 MODULE_DESCRIPTION("Socket-CAN driver for CC770 on the platform bus");
0054 MODULE_LICENSE("GPL v2");
0055 MODULE_ALIAS("platform:" DRV_NAME);
0056
0057 #define CC770_PLATFORM_CAN_CLOCK  16000000
0058
0059 static u8 cc770_platform_read_reg(const struct cc770_priv *priv, int reg)
0060 {
0061     return ioread8(priv->reg_base + reg);
0062 }
0063
0064 static void cc770_platform_write_reg(const struct cc770_priv *priv, int reg,
0065                      u8 val)
0066 {
0067     iowrite8(val, priv->reg_base + reg);
0068 }
0069
0070 static int cc770_get_of_node_data(struct platform_device *pdev,
0071                   struct cc770_priv *priv)
0072 {
0073     struct device_node *np = pdev->dev.of_node;
0074     const u32 *prop;
0075     int prop_size;
0076     u32 clkext;
0077
0078     prop = of_get_property(np, "bosch,external-clock-frequency",
0079                    &prop_size);
0080     if (prop && (prop_size ==  sizeof(u32)))
0081         clkext = *prop;
0082     else
0083         clkext = CC770_PLATFORM_CAN_CLOCK; /* default */
0084     priv->can.clock.freq = clkext;
0085
0086     /* The system clock may not exceed 10 MHz */
0087     if (priv->can.clock.freq > 10000000) {
0088         priv->cpu_interface |= CPUIF_DSC;
0089         priv->can.clock.freq /= 2;
0090     }
0091
0092     /* The memory clock may not exceed 8 MHz */
0093     if (priv->can.clock.freq > 8000000)
0094         priv->cpu_interface |= CPUIF_DMC;
0095
0096     if (of_get_property(np, "bosch,divide-memory-clock", NULL))
0097         priv->cpu_interface |= CPUIF_DMC;
0098     if (of_get_property(np, "bosch,iso-low-speed-mux", NULL))
0099         priv->cpu_interface |= CPUIF_MUX;
0100
0101     if (!of_get_property(np, "bosch,no-comperator-bypass", NULL))
0102         priv->bus_config |= BUSCFG_CBY;
0103     if (of_get_property(np, "bosch,disconnect-rx0-input", NULL))
0104         priv->bus_config |= BUSCFG_DR0;
0105     if (of_get_property(np, "bosch,disconnect-rx1-input", NULL))
0106         priv->bus_config |= BUSCFG_DR1;
0107     if (of_get_property(np, "bosch,disconnect-tx1-output", NULL))
0108         priv->bus_config |= BUSCFG_DT1;
0109     if (of_get_property(np, "bosch,polarity-dominant", NULL))
0110         priv->bus_config |= BUSCFG_POL;
0111
0112     prop = of_get_property(np, "bosch,clock-out-frequency", &prop_size);
0113     if (prop && (prop_size == sizeof(u32)) && *prop > 0) {
0114         u32 cdv = clkext / *prop;
0115         int slew;
0116
0117         if (cdv > 0 && cdv < 16) {
0118             priv->cpu_interface |= CPUIF_CEN;
0119             priv->clkout |= (cdv - 1) & CLKOUT_CD_MASK;
0120
0121             prop = of_get_property(np, "bosch,slew-rate",
0122                            &prop_size);
0123             if (prop && (prop_size == sizeof(u32))) {
0124                 slew = *prop;
0125             } else {
0126                 /* Determine default slew rate */
0127                 slew = (CLKOUT_SL_MASK >>
0128                     CLKOUT_SL_SHIFT) -
0129                     ((cdv * clkext - 1) / 8000000);
0130                 if (slew < 0)
0131                     slew = 0;
0132             }
0133             priv->clkout |= (slew << CLKOUT_SL_SHIFT) &
0134                 CLKOUT_SL_MASK;
0135         } else {
0136             dev_dbg(&pdev->dev, "invalid clock-out-frequency\n");
0137         }
0138     }
0139
0140     return 0;
0141 }
0142
0143 static int cc770_get_platform_data(struct platform_device *pdev,
0144                    struct cc770_priv *priv)
0145 {
0146
0147     struct cc770_platform_data *pdata = dev_get_platdata(&pdev->dev);
0148
0149     priv->can.clock.freq = pdata->osc_freq;
0150     if (priv->cpu_interface & CPUIF_DSC)
0151         priv->can.clock.freq /= 2;
0152     priv->clkout = pdata->cor;
0153     priv->bus_config = pdata->bcr;
0154     priv->cpu_interface = pdata->cir;
0155
0156     return 0;
0157 }
0158
0159 static int cc770_platform_probe(struct platform_device *pdev)
0160 {
0161     struct net_device *dev;
0162     struct cc770_priv *priv;
0163     struct resource *mem;
0164     resource_size_t mem_size;
0165     void __iomem *base;
0166     int err, irq;
0167
0168     mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
0169     irq = platform_get_irq(pdev, 0);
0170     if (!mem || irq <= 0)
0171         return -ENODEV;
0172
0173     mem_size = resource_size(mem);
0174     if (!request_mem_region(mem->start, mem_size, pdev->name))
0175         return -EBUSY;
0176
0177     base = ioremap(mem->start, mem_size);
0178     if (!base) {
0179         err = -ENOMEM;
0180         goto exit_release_mem;
0181     }
0182
0183     dev = alloc_cc770dev(0);
0184     if (!dev) {
0185         err = -ENOMEM;
0186         goto exit_unmap_mem;
0187     }
0188
0189     dev->irq = irq;
0190     priv = netdev_priv(dev);
0191     priv->read_reg = cc770_platform_read_reg;
0192     priv->write_reg = cc770_platform_write_reg;
0193     priv->irq_flags = IRQF_SHARED;
0194     priv->reg_base = base;
0195
0196     if (pdev->dev.of_node)
0197         err = cc770_get_of_node_data(pdev, priv);
0198     else if (dev_get_platdata(&pdev->dev))
0199         err = cc770_get_platform_data(pdev, priv);
0200     else
0201         err = -ENODEV;
0202     if (err)
0203         goto exit_free_cc770;
0204
0205     dev_dbg(&pdev->dev,
0206          "reg_base=0x%p irq=%d clock=%d cpu_interface=0x%02x "
0207          "bus_config=0x%02x clkout=0x%02x\n",
0208          priv->reg_base, dev->irq, priv->can.clock.freq,
0209          priv->cpu_interface, priv->bus_config, priv->clkout);
0210
0211     platform_set_drvdata(pdev, dev);
0212     SET_NETDEV_DEV(dev, &pdev->dev);
0213
0214     err = register_cc770dev(dev);
0215     if (err) {
0216         dev_err(&pdev->dev,
0217             "couldn't register CC700 device (err=%d)\n", err);
0218         goto exit_free_cc770;
0219     }
0220
0221     return 0;
0222
0223 exit_free_cc770:
0224     free_cc770dev(dev);
0225 exit_unmap_mem:
0226     iounmap(base);
0227 exit_release_mem:
0228     release_mem_region(mem->start, mem_size);
0229
0230     return err;
0231 }
0232
0233 static int cc770_platform_remove(struct platform_device *pdev)
0234 {
0235     struct net_device *dev = platform_get_drvdata(pdev);
0236     struct cc770_priv *priv = netdev_priv(dev);
0237     struct resource *mem;
0238
0239     unregister_cc770dev(dev);
0240     iounmap(priv->reg_base);
0241     free_cc770dev(dev);
0242
0243     mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
0244     release_mem_region(mem->start, resource_size(mem));
0245
0246     return 0;
0247 }
0248
0249 static const struct of_device_id cc770_platform_table[] = {
0250     {.compatible = "bosch,cc770"}, /* CC770 from Bosch */
0251     {.compatible = "intc,82527"},  /* AN82527 from Intel CP */
0252     {},
0253 };
0254 MODULE_DEVICE_TABLE(of, cc770_platform_table);
0255
0256 static struct platform_driver cc770_platform_driver = {
0257     .driver = {
0258         .name = DRV_NAME,
0259         .of_match_table = cc770_platform_table,
0260     },
0261     .probe = cc770_platform_probe,
0262     .remove = cc770_platform_remove,
0263 };
0264
0265 module_platform_driver(cc770_platform_driver);