274 lines
7.1 KiB
C
Executable file
274 lines
7.1 KiB
C
Executable file
/*
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* Driver for CC770 and AN82527 CAN controllers on the platform bus
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*
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* Copyright (C) 2009, 2011 Wolfgang Grandegger <wg@grandegger.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the version 2 of the GNU General Public License
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* as published by the Free Software Foundation
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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/*
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* If platform data are used you should have similar definitions
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* in your board-specific code:
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*
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* static struct cc770_platform_data myboard_cc770_pdata = {
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* .osc_freq = 16000000,
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* .cir = 0x41,
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* .cor = 0x20,
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* .bcr = 0x40,
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* };
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*
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* Please see include/linux/can/platform/cc770.h for description of
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* above fields.
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*
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* If the device tree is used, you need a CAN node definition in your
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* DTS file similar to:
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*
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* can@3,100 {
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* compatible = "bosch,cc770";
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* reg = <3 0x100 0x80>;
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* interrupts = <2 0>;
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* interrupt-parent = <&mpic>;
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* bosch,external-clock-frequency = <16000000>;
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* };
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*
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* See "Documentation/devicetree/bindings/net/can/cc770.txt" for further
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* information.
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/interrupt.h>
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#include <linux/netdevice.h>
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#include <linux/delay.h>
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#include <linux/platform_device.h>
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#include <linux/of.h>
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#include <linux/can.h>
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#include <linux/can/dev.h>
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#include <linux/can/platform/cc770.h>
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#include "cc770.h"
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#define DRV_NAME "cc770_platform"
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MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
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MODULE_DESCRIPTION("Socket-CAN driver for CC770 on the platform bus");
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MODULE_LICENSE("GPL v2");
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MODULE_ALIAS("platform:" DRV_NAME);
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#define CC770_PLATFORM_CAN_CLOCK 16000000
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static u8 cc770_platform_read_reg(const struct cc770_priv *priv, int reg)
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{
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return ioread8(priv->reg_base + reg);
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}
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static void cc770_platform_write_reg(const struct cc770_priv *priv, int reg,
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u8 val)
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{
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iowrite8(val, priv->reg_base + reg);
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}
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static int cc770_get_of_node_data(struct platform_device *pdev,
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struct cc770_priv *priv)
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{
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struct device_node *np = pdev->dev.of_node;
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const u32 *prop;
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int prop_size;
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u32 clkext;
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prop = of_get_property(np, "bosch,external-clock-frequency",
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&prop_size);
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if (prop && (prop_size == sizeof(u32)))
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clkext = *prop;
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else
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clkext = CC770_PLATFORM_CAN_CLOCK; /* default */
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priv->can.clock.freq = clkext;
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/* The system clock may not exceed 10 MHz */
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if (priv->can.clock.freq > 10000000) {
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priv->cpu_interface |= CPUIF_DSC;
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priv->can.clock.freq /= 2;
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}
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/* The memory clock may not exceed 8 MHz */
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if (priv->can.clock.freq > 8000000)
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priv->cpu_interface |= CPUIF_DMC;
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if (of_get_property(np, "bosch,divide-memory-clock", NULL))
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priv->cpu_interface |= CPUIF_DMC;
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if (of_get_property(np, "bosch,iso-low-speed-mux", NULL))
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priv->cpu_interface |= CPUIF_MUX;
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if (!of_get_property(np, "bosch,no-comperator-bypass", NULL))
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priv->bus_config |= BUSCFG_CBY;
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if (of_get_property(np, "bosch,disconnect-rx0-input", NULL))
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priv->bus_config |= BUSCFG_DR0;
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if (of_get_property(np, "bosch,disconnect-rx1-input", NULL))
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priv->bus_config |= BUSCFG_DR1;
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if (of_get_property(np, "bosch,disconnect-tx1-output", NULL))
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priv->bus_config |= BUSCFG_DT1;
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if (of_get_property(np, "bosch,polarity-dominant", NULL))
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priv->bus_config |= BUSCFG_POL;
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prop = of_get_property(np, "bosch,clock-out-frequency", &prop_size);
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if (prop && (prop_size == sizeof(u32)) && *prop > 0) {
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u32 cdv = clkext / *prop;
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int slew;
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if (cdv > 0 && cdv < 16) {
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priv->cpu_interface |= CPUIF_CEN;
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priv->clkout |= (cdv - 1) & CLKOUT_CD_MASK;
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prop = of_get_property(np, "bosch,slew-rate",
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&prop_size);
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if (prop && (prop_size == sizeof(u32))) {
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slew = *prop;
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} else {
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/* Determine default slew rate */
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slew = (CLKOUT_SL_MASK >>
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CLKOUT_SL_SHIFT) -
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((cdv * clkext - 1) / 8000000);
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if (slew < 0)
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slew = 0;
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}
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priv->clkout |= (slew << CLKOUT_SL_SHIFT) &
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CLKOUT_SL_MASK;
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} else {
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dev_dbg(&pdev->dev, "invalid clock-out-frequency\n");
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}
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}
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return 0;
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}
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static int cc770_get_platform_data(struct platform_device *pdev,
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struct cc770_priv *priv)
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{
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struct cc770_platform_data *pdata = dev_get_platdata(&pdev->dev);
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priv->can.clock.freq = pdata->osc_freq;
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if (priv->cpu_interface & CPUIF_DSC)
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priv->can.clock.freq /= 2;
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priv->clkout = pdata->cor;
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priv->bus_config = pdata->bcr;
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priv->cpu_interface = pdata->cir;
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return 0;
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}
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static int cc770_platform_probe(struct platform_device *pdev)
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{
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struct net_device *dev;
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struct cc770_priv *priv;
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struct resource *mem;
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resource_size_t mem_size;
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void __iomem *base;
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int err, irq;
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mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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irq = platform_get_irq(pdev, 0);
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if (!mem || irq <= 0)
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return -ENODEV;
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mem_size = resource_size(mem);
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if (!request_mem_region(mem->start, mem_size, pdev->name))
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return -EBUSY;
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base = ioremap(mem->start, mem_size);
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if (!base) {
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err = -ENOMEM;
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goto exit_release_mem;
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}
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dev = alloc_cc770dev(0);
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if (!dev) {
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err = -ENOMEM;
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goto exit_unmap_mem;
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}
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dev->irq = irq;
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priv = netdev_priv(dev);
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priv->read_reg = cc770_platform_read_reg;
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priv->write_reg = cc770_platform_write_reg;
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priv->irq_flags = IRQF_SHARED;
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priv->reg_base = base;
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if (pdev->dev.of_node)
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err = cc770_get_of_node_data(pdev, priv);
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else if (dev_get_platdata(&pdev->dev))
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err = cc770_get_platform_data(pdev, priv);
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else
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err = -ENODEV;
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if (err)
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goto exit_free_cc770;
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dev_dbg(&pdev->dev,
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"reg_base=0x%p irq=%d clock=%d cpu_interface=0x%02x "
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"bus_config=0x%02x clkout=0x%02x\n",
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priv->reg_base, dev->irq, priv->can.clock.freq,
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priv->cpu_interface, priv->bus_config, priv->clkout);
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platform_set_drvdata(pdev, dev);
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SET_NETDEV_DEV(dev, &pdev->dev);
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err = register_cc770dev(dev);
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if (err) {
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dev_err(&pdev->dev,
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"couldn't register CC700 device (err=%d)\n", err);
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goto exit_free_cc770;
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}
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return 0;
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exit_free_cc770:
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free_cc770dev(dev);
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exit_unmap_mem:
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iounmap(base);
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exit_release_mem:
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release_mem_region(mem->start, mem_size);
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return err;
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}
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static int cc770_platform_remove(struct platform_device *pdev)
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{
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struct net_device *dev = platform_get_drvdata(pdev);
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struct cc770_priv *priv = netdev_priv(dev);
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struct resource *mem;
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unregister_cc770dev(dev);
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iounmap(priv->reg_base);
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free_cc770dev(dev);
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mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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release_mem_region(mem->start, resource_size(mem));
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return 0;
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}
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static const struct of_device_id cc770_platform_table[] = {
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{.compatible = "bosch,cc770"}, /* CC770 from Bosch */
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{.compatible = "intc,82527"}, /* AN82527 from Intel CP */
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{},
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};
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MODULE_DEVICE_TABLE(of, cc770_platform_table);
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static struct platform_driver cc770_platform_driver = {
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.driver = {
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.name = DRV_NAME,
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.of_match_table = cc770_platform_table,
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},
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.probe = cc770_platform_probe,
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.remove = cc770_platform_remove,
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};
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module_platform_driver(cc770_platform_driver);
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