From d1a277c584d0862dbf51991baea947ea5f2ce6bf Mon Sep 17 00:00:00 2001 From: Wolfgang Grandegger Date: Sat, 30 May 2009 07:55:50 +0000 Subject: [PATCH] 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 Signed-off-by: David S. Miller --- .../powerpc/dts-bindings/can/sja1000.txt | 53 ++++ drivers/net/can/Kconfig | 9 + drivers/net/can/sja1000/Makefile | 1 + drivers/net/can/sja1000/sja1000_of_platform.c | 233 ++++++++++++++++++ include/linux/can/platform/sja1000.h | 3 + 5 files changed, 299 insertions(+) create mode 100644 Documentation/powerpc/dts-bindings/can/sja1000.txt create mode 100644 drivers/net/can/sja1000/sja1000_of_platform.c diff --git a/Documentation/powerpc/dts-bindings/can/sja1000.txt b/Documentation/powerpc/dts-bindings/can/sja1000.txt new file mode 100644 index 000000000000..d6d209ded937 --- /dev/null +++ b/Documentation/powerpc/dts-bindings/can/sja1000.txt @@ -0,0 +1,53 @@ +Memory mapped SJA1000 CAN controller from NXP (formerly Philips) + +Required properties: + +- compatible : should be "nxp,sja1000". + +- reg : should specify the chip select, address offset and size required + to map the registers of the SJA1000. The size is usually 0x80. + +- interrupts: property with a value describing the interrupt source + (number and sensitivity) required for the SJA1000. + +Optional properties: + +- nxp,external-clock-frequency : Frequency of the external oscillator + clock in Hz. Note that the internal clock frequency used by the + SJA1000 is half of that value. If not specified, a default value + of 16000000 (16 MHz) is used. + +- nxp,tx-output-mode : operation mode of the TX output control logic: + <0x0> : bi-phase output mode + <0x1> : normal output mode (default) + <0x2> : test output mode + <0x3> : clock output mode + +- nxp,tx-output-config : TX output pin configuration: + <0x01> : TX0 invert + <0x02> : TX0 pull-down (default) + <0x04> : TX0 pull-up + <0x06> : TX0 push-pull + <0x08> : TX1 invert + <0x10> : TX1 pull-down + <0x20> : TX1 pull-up + <0x30> : TX1 push-pull + +- nxp,clock-out-frequency : clock frequency in Hz on the CLKOUT pin. + If not specified or if the specified value is 0, the CLKOUT pin + will be disabled. + +- nxp,no-comparator-bypass : Allows to disable the CAN input comperator. + +For futher information, please have a look to the SJA1000 data sheet. + +Examples: + +can@3,100 { + compatible = "nxp,sja1000"; + reg = <3 0x100 0x80>; + interrupts = <2 0>; + interrupt-parent = <&mpic>; + nxp,external-clock-frequency = <16000000>; +}; + diff --git a/drivers/net/can/Kconfig b/drivers/net/can/Kconfig index cfd6c5a285fa..d5e18812bf49 100644 --- a/drivers/net/can/Kconfig +++ b/drivers/net/can/Kconfig @@ -51,6 +51,15 @@ config CAN_SJA1000_PLATFORM boards from Phytec (http://www.phytec.de) like the PCM027, PCM038. +config CAN_SJA1000_OF_PLATFORM + depends on CAN_SJA1000 && PPC_OF + tristate "Generic OF Platform Bus based SJA1000 driver" + ---help--- + This driver adds support for the SJA1000 chips connected to + the OpenFirmware "platform bus" found on embedded systems with + OpenFirmware bindings, e.g. if you have a PowerPC based system + you may want to enable this option. + config CAN_EMS_PCI tristate "EMS CPC-PCI and CPC-PCIe Card" depends on PCI && CAN_SJA1000 diff --git a/drivers/net/can/sja1000/Makefile b/drivers/net/can/sja1000/Makefile index d6c631f9e665..9d0c08da273c 100644 --- a/drivers/net/can/sja1000/Makefile +++ b/drivers/net/can/sja1000/Makefile @@ -4,6 +4,7 @@ obj-$(CONFIG_CAN_SJA1000) += sja1000.o obj-$(CONFIG_CAN_SJA1000_PLATFORM) += sja1000_platform.o +obj-$(CONFIG_CAN_SJA1000_OF_PLATFORM) += sja1000_of_platform.o obj-$(CONFIG_CAN_EMS_PCI) += ems_pci.o obj-$(CONFIG_CAN_KVASER_PCI) += kvaser_pci.o diff --git a/drivers/net/can/sja1000/sja1000_of_platform.c b/drivers/net/can/sja1000/sja1000_of_platform.c new file mode 100644 index 000000000000..aa953fb4b8d0 --- /dev/null +++ b/drivers/net/can/sja1000/sja1000_of_platform.c @@ -0,0 +1,233 @@ +/* + * Driver for SJA1000 CAN controllers on the OpenFirmware platform bus + * + * Copyright (C) 2008-2009 Wolfgang Grandegger + * + * 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, write to the Free Software Foundation, + * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + */ + +/* 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/powerpc/dts-bindings/can/sja1000.txt" for further + * information. + */ + +#include +#include +#include +#include +#include +#include +#include + +#include +#include + +#include "sja1000.h" + +#define DRV_NAME "sja1000_of_platform" + +MODULE_AUTHOR("Wolfgang Grandegger "); +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 in_8(priv->reg_base + reg); +} + +static void sja1000_ofp_write_reg(const struct sja1000_priv *priv, + int reg, u8 val) +{ + out_8(priv->reg_base + reg, val); +} + +static int __devexit sja1000_ofp_remove(struct of_device *ofdev) +{ + struct net_device *dev = dev_get_drvdata(&ofdev->dev); + struct sja1000_priv *priv = netdev_priv(dev); + struct device_node *np = ofdev->node; + struct resource res; + + dev_set_drvdata(&ofdev->dev, NULL); + + 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 __devinit sja1000_ofp_probe(struct of_device *ofdev, + const struct of_device_id *id) +{ + struct device_node *np = ofdev->node; + struct net_device *dev; + struct sja1000_priv *priv; + struct resource res; + const u32 *prop; + int err, irq, res_size, prop_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 %#x..%#x\n", + res.start, res.end); + return -EBUSY; + } + + base = ioremap_nocache(res.start, res_size); + if (!base) { + dev_err(&ofdev->dev, "couldn't ioremap %#x..%#x\n", + res.start, res.end); + err = -ENOMEM; + goto exit_release_mem; + } + + irq = irq_of_parse_and_map(np, 0); + if (irq == NO_IRQ) { + 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; + + prop = of_get_property(np, "nxp,external-clock-frequency", &prop_size); + if (prop && (prop_size == sizeof(u32))) + priv->can.clock.freq = *prop / 2; + else + priv->can.clock.freq = SJA1000_OFP_CAN_CLOCK; /* default */ + + prop = of_get_property(np, "nxp,tx-output-mode", &prop_size); + if (prop && (prop_size == sizeof(u32))) + priv->ocr |= *prop & OCR_MODE_MASK; + else + priv->ocr |= OCR_MODE_NORMAL; /* default */ + + prop = of_get_property(np, "nxp,tx-output-config", &prop_size); + if (prop && (prop_size == sizeof(u32))) + priv->ocr |= (*prop << OCR_TX_SHIFT) & OCR_TX_MASK; + else + priv->ocr |= OCR_TX0_PULLDOWN; /* default */ + + prop = of_get_property(np, "nxp,clock-out-frequency", &prop_size); + if (prop && (prop_size == sizeof(u32)) && *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 */ + } + + prop = of_get_property(np, "nxp,no-comparator-bypass", NULL); + if (!prop) + 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); + + dev_set_drvdata(&ofdev->dev, 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 __devinitdata sja1000_ofp_table[] = { + {.compatible = "nxp,sja1000"}, + {}, +}; + +static struct of_platform_driver sja1000_ofp_driver = { + .owner = THIS_MODULE, + .name = DRV_NAME, + .probe = sja1000_ofp_probe, + .remove = __devexit_p(sja1000_ofp_remove), + .match_table = sja1000_ofp_table, +}; + +static int __init sja1000_ofp_init(void) +{ + return of_register_platform_driver(&sja1000_ofp_driver); +} +module_init(sja1000_ofp_init); + +static void __exit sja1000_ofp_exit(void) +{ + return of_unregister_platform_driver(&sja1000_ofp_driver); +}; +module_exit(sja1000_ofp_exit); diff --git a/include/linux/can/platform/sja1000.h b/include/linux/can/platform/sja1000.h index 37966e630ff5..01ee2aeb048d 100644 --- a/include/linux/can/platform/sja1000.h +++ b/include/linux/can/platform/sja1000.h @@ -13,6 +13,7 @@ #define OCR_MODE_TEST 0x01 #define OCR_MODE_NORMAL 0x02 #define OCR_MODE_CLOCK 0x03 +#define OCR_MODE_MASK 0x07 #define OCR_TX0_INVERT 0x04 #define OCR_TX0_PULLDOWN 0x08 #define OCR_TX0_PULLUP 0x10 @@ -21,6 +22,8 @@ #define OCR_TX1_PULLDOWN 0x40 #define OCR_TX1_PULLUP 0x80 #define OCR_TX1_PUSHPULL 0xc0 +#define OCR_TX_MASK 0xfc +#define OCR_TX_SHIFT 2 struct sja1000_platform_data { u32 clock; /* CAN bus oscillator frequency in Hz */ -- 2.39.2