* [net-next-2.6 PATCH 3/3] can: sja1000: generic OF platform bus driver
[not found] <20090530175547.772116783@denx.de>
@ 2009-05-30 17:55 ` Wolfgang Grandegger
0 siblings, 0 replies; only message in thread
From: Wolfgang Grandegger @ 2009-05-30 17:55 UTC (permalink / raw)
To: netdev; +Cc: socketcan-core, devicetree-discuss, Wolfgang Grandegger
[-- Attachment #1: sja1000-of-platform-driver.patch --]
[-- Type: text/plain, Size: 11735 bytes --]
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>
---
Documentation/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(+)
Index: net-next-2.6/drivers/net/can/Kconfig
===================================================================
--- net-next-2.6.orig/drivers/net/can/Kconfig 2009-05-30 19:48:32.736721524 +0200
+++ net-next-2.6/drivers/net/can/Kconfig 2009-05-30 19:48:40.388719327 +0200
@@ -51,6 +51,15 @@
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
Index: net-next-2.6/drivers/net/can/sja1000/Makefile
===================================================================
--- net-next-2.6.orig/drivers/net/can/sja1000/Makefile 2009-05-30 19:48:32.737720828 +0200
+++ net-next-2.6/drivers/net/can/sja1000/Makefile 2009-05-30 19:48:40.389719190 +0200
@@ -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
Index: net-next-2.6/drivers/net/can/sja1000/sja1000_of_platform.c
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ net-next-2.6/drivers/net/can/sja1000/sja1000_of_platform.c 2009-05-30 19:48:40.397718650 +0200
@@ -0,0 +1,233 @@
+/*
+ * 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, 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 <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/netdevice.h>
+#include <linux/delay.h>
+#include <linux/can.h>
+#include <linux/can/dev.h>
+
+#include <linux/of_platform.h>
+#include <asm/prom.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 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);
Index: net-next-2.6/Documentation/powerpc/dts-bindings/can/sja1000.txt
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ net-next-2.6/Documentation/powerpc/dts-bindings/can/sja1000.txt 2009-05-30 19:48:40.399720890 +0200
@@ -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>;
+};
+
Index: net-next-2.6/include/linux/can/platform/sja1000.h
===================================================================
--- net-next-2.6.orig/include/linux/can/platform/sja1000.h 2009-05-30 19:48:32.738720411 +0200
+++ net-next-2.6/include/linux/can/platform/sja1000.h 2009-05-30 19:48:40.402720478 +0200
@@ -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 */
^ permalink raw reply [flat|nested] only message in thread