forked from Minki/linux
can: sja1000: generic OF platform bus driver
This patch adds a generic driver for SJA1000 chips on the OpenFirmware
platform bus found on embedded PowerPC systems. You need a SJA1000 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 also Documentation/powerpc/dts-bindings/can/sja1000.txt.
CC: devicetree-discuss@ozlabs.org
Signed-off-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Wolfgang Grandegger
David S. Miller
parent
255a915431
commit
d1a277c584
53
Documentation/powerpc/dts-bindings/can/sja1000.txt
Normal file
53
Documentation/powerpc/dts-bindings/can/sja1000.txt
Normal file
@ -0,0 +1,53 @@
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Memory mapped SJA1000 CAN controller from NXP (formerly Philips)
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Required properties:
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- compatible : should be "nxp,sja1000".
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- reg : should specify the chip select, address offset and size required
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to map the registers of the SJA1000. The size is usually 0x80.
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- interrupts: property with a value describing the interrupt source
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(number and sensitivity) required for the SJA1000.
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Optional properties:
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- nxp,external-clock-frequency : Frequency of the external oscillator
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clock in Hz. Note that the internal clock frequency used by the
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SJA1000 is half of that value. If not specified, a default value
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of 16000000 (16 MHz) is used.
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- nxp,tx-output-mode : operation mode of the TX output control logic:
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<0x0> : bi-phase output mode
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<0x1> : normal output mode (default)
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<0x2> : test output mode
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<0x3> : clock output mode
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- nxp,tx-output-config : TX output pin configuration:
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<0x01> : TX0 invert
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<0x02> : TX0 pull-down (default)
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<0x04> : TX0 pull-up
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<0x06> : TX0 push-pull
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<0x08> : TX1 invert
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<0x10> : TX1 pull-down
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<0x20> : TX1 pull-up
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<0x30> : TX1 push-pull
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- nxp,clock-out-frequency : clock frequency in Hz on the CLKOUT pin.
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If not specified or if the specified value is 0, the CLKOUT pin
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will be disabled.
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- nxp,no-comparator-bypass : Allows to disable the CAN input comperator.
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For futher information, please have a look to the SJA1000 data sheet.
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Examples:
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can@3,100 {
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compatible = "nxp,sja1000";
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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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nxp,external-clock-frequency = <16000000>;
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};
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@ -51,6 +51,15 @@ config CAN_SJA1000_PLATFORM
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boards from Phytec (http://www.phytec.de) like the PCM027,
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PCM038.
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config CAN_SJA1000_OF_PLATFORM
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depends on CAN_SJA1000 && PPC_OF
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tristate "Generic OF Platform Bus based SJA1000 driver"
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---help---
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This driver adds support for the SJA1000 chips connected to
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the OpenFirmware "platform bus" found on embedded systems with
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OpenFirmware bindings, e.g. if you have a PowerPC based system
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you may want to enable this option.
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config CAN_EMS_PCI
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tristate "EMS CPC-PCI and CPC-PCIe Card"
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depends on PCI && CAN_SJA1000
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@ -4,6 +4,7 @@
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obj-$(CONFIG_CAN_SJA1000) += sja1000.o
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obj-$(CONFIG_CAN_SJA1000_PLATFORM) += sja1000_platform.o
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obj-$(CONFIG_CAN_SJA1000_OF_PLATFORM) += sja1000_of_platform.o
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obj-$(CONFIG_CAN_EMS_PCI) += ems_pci.o
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obj-$(CONFIG_CAN_KVASER_PCI) += kvaser_pci.o
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233
drivers/net/can/sja1000/sja1000_of_platform.c
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233
drivers/net/can/sja1000/sja1000_of_platform.c
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@ -0,0 +1,233 @@
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/*
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* Driver for SJA1000 CAN controllers on the OpenFirmware platform bus
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*
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* Copyright (C) 2008-2009 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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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software Foundation,
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* Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*/
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/* This is a generic driver for SJA1000 chips on the OpenFirmware platform
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* bus found on embedded PowerPC systems. You need a SJA1000 CAN node
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* definition in your flattened device tree source (DTS) file similar to:
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*
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* can@3,100 {
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* compatible = "nxp,sja1000";
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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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* nxp,external-clock-frequency = <16000000>;
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* };
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*
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* See "Documentation/powerpc/dts-bindings/can/sja1000.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/can.h>
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#include <linux/can/dev.h>
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#include <linux/of_platform.h>
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#include <asm/prom.h>
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#include "sja1000.h"
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#define DRV_NAME "sja1000_of_platform"
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MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
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MODULE_DESCRIPTION("Socket-CAN driver for SJA1000 on the OF platform bus");
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MODULE_LICENSE("GPL v2");
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#define SJA1000_OFP_CAN_CLOCK (16000000 / 2)
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#define SJA1000_OFP_OCR OCR_TX0_PULLDOWN
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#define SJA1000_OFP_CDR (CDR_CBP | CDR_CLK_OFF)
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static u8 sja1000_ofp_read_reg(const struct sja1000_priv *priv, int reg)
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{
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return in_8(priv->reg_base + reg);
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}
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static void sja1000_ofp_write_reg(const struct sja1000_priv *priv,
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int reg, u8 val)
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{
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out_8(priv->reg_base + reg, val);
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}
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static int __devexit sja1000_ofp_remove(struct of_device *ofdev)
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{
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struct net_device *dev = dev_get_drvdata(&ofdev->dev);
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struct sja1000_priv *priv = netdev_priv(dev);
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struct device_node *np = ofdev->node;
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struct resource res;
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dev_set_drvdata(&ofdev->dev, NULL);
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unregister_sja1000dev(dev);
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free_sja1000dev(dev);
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iounmap(priv->reg_base);
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irq_dispose_mapping(dev->irq);
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of_address_to_resource(np, 0, &res);
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release_mem_region(res.start, resource_size(&res));
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return 0;
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}
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static int __devinit sja1000_ofp_probe(struct of_device *ofdev,
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const struct of_device_id *id)
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{
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struct device_node *np = ofdev->node;
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struct net_device *dev;
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struct sja1000_priv *priv;
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struct resource res;
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const u32 *prop;
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int err, irq, res_size, prop_size;
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void __iomem *base;
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err = of_address_to_resource(np, 0, &res);
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if (err) {
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dev_err(&ofdev->dev, "invalid address\n");
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return err;
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}
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res_size = resource_size(&res);
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if (!request_mem_region(res.start, res_size, DRV_NAME)) {
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dev_err(&ofdev->dev, "couldn't request %#x..%#x\n",
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res.start, res.end);
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return -EBUSY;
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}
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base = ioremap_nocache(res.start, res_size);
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if (!base) {
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dev_err(&ofdev->dev, "couldn't ioremap %#x..%#x\n",
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res.start, res.end);
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err = -ENOMEM;
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goto exit_release_mem;
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}
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irq = irq_of_parse_and_map(np, 0);
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if (irq == NO_IRQ) {
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dev_err(&ofdev->dev, "no irq found\n");
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err = -ENODEV;
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goto exit_unmap_mem;
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}
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dev = alloc_sja1000dev(0);
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if (!dev) {
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err = -ENOMEM;
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goto exit_dispose_irq;
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}
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priv = netdev_priv(dev);
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priv->read_reg = sja1000_ofp_read_reg;
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priv->write_reg = sja1000_ofp_write_reg;
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prop = of_get_property(np, "nxp,external-clock-frequency", &prop_size);
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if (prop && (prop_size == sizeof(u32)))
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priv->can.clock.freq = *prop / 2;
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else
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priv->can.clock.freq = SJA1000_OFP_CAN_CLOCK; /* default */
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prop = of_get_property(np, "nxp,tx-output-mode", &prop_size);
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if (prop && (prop_size == sizeof(u32)))
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priv->ocr |= *prop & OCR_MODE_MASK;
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else
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priv->ocr |= OCR_MODE_NORMAL; /* default */
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prop = of_get_property(np, "nxp,tx-output-config", &prop_size);
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if (prop && (prop_size == sizeof(u32)))
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priv->ocr |= (*prop << OCR_TX_SHIFT) & OCR_TX_MASK;
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else
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priv->ocr |= OCR_TX0_PULLDOWN; /* default */
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prop = of_get_property(np, "nxp,clock-out-frequency", &prop_size);
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if (prop && (prop_size == sizeof(u32)) && *prop) {
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u32 divider = priv->can.clock.freq * 2 / *prop;
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if (divider > 1)
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priv->cdr |= divider / 2 - 1;
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else
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priv->cdr |= CDR_CLKOUT_MASK;
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} else {
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priv->cdr |= CDR_CLK_OFF; /* default */
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}
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prop = of_get_property(np, "nxp,no-comparator-bypass", NULL);
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if (!prop)
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priv->cdr |= CDR_CBP; /* default */
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priv->irq_flags = IRQF_SHARED;
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priv->reg_base = base;
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dev->irq = irq;
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dev_info(&ofdev->dev,
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"reg_base=0x%p irq=%d clock=%d ocr=0x%02x cdr=0x%02x\n",
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priv->reg_base, dev->irq, priv->can.clock.freq,
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priv->ocr, priv->cdr);
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dev_set_drvdata(&ofdev->dev, dev);
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SET_NETDEV_DEV(dev, &ofdev->dev);
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err = register_sja1000dev(dev);
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if (err) {
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dev_err(&ofdev->dev, "registering %s failed (err=%d)\n",
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DRV_NAME, err);
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goto exit_free_sja1000;
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}
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return 0;
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exit_free_sja1000:
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free_sja1000dev(dev);
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exit_dispose_irq:
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irq_dispose_mapping(irq);
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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(res.start, res_size);
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return err;
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}
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static struct of_device_id __devinitdata sja1000_ofp_table[] = {
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{.compatible = "nxp,sja1000"},
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{},
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};
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static struct of_platform_driver sja1000_ofp_driver = {
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.owner = THIS_MODULE,
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.name = DRV_NAME,
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.probe = sja1000_ofp_probe,
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.remove = __devexit_p(sja1000_ofp_remove),
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.match_table = sja1000_ofp_table,
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};
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static int __init sja1000_ofp_init(void)
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{
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return of_register_platform_driver(&sja1000_ofp_driver);
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}
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module_init(sja1000_ofp_init);
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static void __exit sja1000_ofp_exit(void)
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{
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return of_unregister_platform_driver(&sja1000_ofp_driver);
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};
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module_exit(sja1000_ofp_exit);
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@ -13,6 +13,7 @@
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#define OCR_MODE_TEST 0x01
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#define OCR_MODE_NORMAL 0x02
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#define OCR_MODE_CLOCK 0x03
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#define OCR_MODE_MASK 0x07
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#define OCR_TX0_INVERT 0x04
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#define OCR_TX0_PULLDOWN 0x08
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#define OCR_TX0_PULLUP 0x10
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@ -21,6 +22,8 @@
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#define OCR_TX1_PULLDOWN 0x40
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#define OCR_TX1_PULLUP 0x80
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#define OCR_TX1_PUSHPULL 0xc0
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#define OCR_TX_MASK 0xfc
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#define OCR_TX_SHIFT 2
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struct sja1000_platform_data {
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u32 clock; /* CAN bus oscillator frequency in Hz */
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