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/*
* Driver for SJA1000 CAN controllers on the OpenFirmware platform bus
*
* Copyright (C) 2008-2009 Wolfgang Grandegger <wg@grandegger.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the version 2 of the GNU General Public License
* as published by the Free Software Foundation
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
/* This is a generic driver for SJA1000 chips on the OpenFirmware platform
* bus found on embedded PowerPC systems. You need a SJA1000 CAN node
* definition in your flattened device tree source (DTS) file similar to:
*
* can@3,100 {
* compatible = "nxp,sja1000";
* reg = <3 0x100 0x80>;
* interrupts = <2 0>;
* interrupt-parent = <&mpic>;
* nxp,external-clock-frequency = <16000000>;
* };
*
* See "Documentation/devicetree/bindings/net/can/sja1000.txt" for further
* information.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/netdevice.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/can/dev.h>
#include <linux/of_platform.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include "sja1000.h"
#define DRV_NAME "sja1000_of_platform"
MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
MODULE_DESCRIPTION("Socket-CAN driver for SJA1000 on the OF platform bus");
MODULE_LICENSE("GPL v2");
#define SJA1000_OFP_CAN_CLOCK (16000000 / 2)
#define SJA1000_OFP_OCR OCR_TX0_PULLDOWN
#define SJA1000_OFP_CDR (CDR_CBP | CDR_CLK_OFF)
static u8 sja1000_ofp_read_reg(const struct sja1000_priv *priv, int reg)
{
return ioread8(priv->reg_base + reg);
}
static void sja1000_ofp_write_reg(const struct sja1000_priv *priv,
int reg, u8 val)
{
iowrite8(val, priv->reg_base + reg);
}
static int sja1000_ofp_remove(struct platform_device *ofdev)
{
struct net_device *dev = platform_get_drvdata(ofdev);
struct sja1000_priv *priv = netdev_priv(dev);
struct device_node *np = ofdev->dev.of_node;
struct resource res;
unregister_sja1000dev(dev);
free_sja1000dev(dev);
iounmap(priv->reg_base);
irq_dispose_mapping(dev->irq);
of_address_to_resource(np, 0, &res);
release_mem_region(res.start, resource_size(&res));
return 0;
}
static int sja1000_ofp_probe(struct platform_device *ofdev)
{
struct device_node *np = ofdev->dev.of_node;
struct net_device *dev;
struct sja1000_priv *priv;
struct resource res;
u32 prop;
int err, irq, res_size;
void __iomem *base;
err = of_address_to_resource(np, 0, &res);
if (err) {
dev_err(&ofdev->dev, "invalid address\n");
return err;
}
res_size = resource_size(&res);
if (!request_mem_region(res.start, res_size, DRV_NAME)) {
dev_err(&ofdev->dev, "couldn't request %pR\n", &res);
return -EBUSY;
}
base = ioremap_nocache(res.start, res_size);
if (!base) {
dev_err(&ofdev->dev, "couldn't ioremap %pR\n", &res);
err = -ENOMEM;
goto exit_release_mem;
}
irq = irq_of_parse_and_map(np, 0);
if (irq == 0) {
dev_err(&ofdev->dev, "no irq found\n");
err = -ENODEV;
goto exit_unmap_mem;
}
dev = alloc_sja1000dev(0);
if (!dev) {
err = -ENOMEM;
goto exit_dispose_irq;
}
priv = netdev_priv(dev);
priv->read_reg = sja1000_ofp_read_reg;
priv->write_reg = sja1000_ofp_write_reg;
err = of_property_read_u32(np, "nxp,external-clock-frequency", &prop);
if (!err)
priv->can.clock.freq = prop / 2;
else
priv->can.clock.freq = SJA1000_OFP_CAN_CLOCK; /* default */
err = of_property_read_u32(np, "nxp,tx-output-mode", &prop);
if (!err)
priv->ocr |= prop & OCR_MODE_MASK;
else
priv->ocr |= OCR_MODE_NORMAL; /* default */
err = of_property_read_u32(np, "nxp,tx-output-config", &prop);
if (!err)
priv->ocr |= (prop << OCR_TX_SHIFT) & OCR_TX_MASK;
else
priv->ocr |= OCR_TX0_PULLDOWN; /* default */
err = of_property_read_u32(np, "nxp,clock-out-frequency", &prop);
if (!err && prop) {
u32 divider = priv->can.clock.freq * 2 / prop;
if (divider > 1)
priv->cdr |= divider / 2 - 1;
else
priv->cdr |= CDR_CLKOUT_MASK;
} else {
priv->cdr |= CDR_CLK_OFF; /* default */
}
if (!of_property_read_bool(np, "nxp,no-comparator-bypass"))
priv->cdr |= CDR_CBP; /* default */
priv->irq_flags = IRQF_SHARED;
priv->reg_base = base;
dev->irq = irq;
dev_info(&ofdev->dev,
"reg_base=0x%p irq=%d clock=%d ocr=0x%02x cdr=0x%02x\n",
priv->reg_base, dev->irq, priv->can.clock.freq,
priv->ocr, priv->cdr);
platform_set_drvdata(ofdev, dev);
SET_NETDEV_DEV(dev, &ofdev->dev);
err = register_sja1000dev(dev);
if (err) {
dev_err(&ofdev->dev, "registering %s failed (err=%d)\n",
DRV_NAME, err);
goto exit_free_sja1000;
}
return 0;
exit_free_sja1000:
free_sja1000dev(dev);
exit_dispose_irq:
irq_dispose_mapping(irq);
exit_unmap_mem:
iounmap(base);
exit_release_mem:
release_mem_region(res.start, res_size);
return err;
}
static struct of_device_id sja1000_ofp_table[] = {
{.compatible = "nxp,sja1000"},
{},
};
MODULE_DEVICE_TABLE(of, sja1000_ofp_table);
static struct platform_driver sja1000_ofp_driver = {
.driver = {
.owner = THIS_MODULE,
.name = DRV_NAME,
.of_match_table = sja1000_ofp_table,
},
.probe = sja1000_ofp_probe,
.remove = sja1000_ofp_remove,
};
module_platform_driver(sja1000_ofp_driver);
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