[PATCH net-next v4 3/4] can: cc770: add platform bus driver for the CC770 and AN82527
Wolfgang Grandegger
wg at grandegger.com
Tue Nov 29 20:11:29 EST 2011
This driver works with both, static platform data and device tree
bindings. It has been tested on a TQM855L board with two AN82527
CAN controllers on the local bus.
CC: Devicetree-discuss at lists.ozlabs.org
CC: linuxppc-dev at ozlabs.org
CC: Kumar Gala <galak at kernel.crashing.org>
Signed-off-by: Wolfgang Grandegger <wg at grandegger.com>
Acked-by: Marc Kleine-Budde <mkl at pengutronix.de>
---
.../devicetree/bindings/net/can/cc770.txt | 56 ++++
drivers/net/can/cc770/Kconfig | 7 +
drivers/net/can/cc770/Makefile | 1 +
drivers/net/can/cc770/cc770_platform.c | 273 ++++++++++++++++++++
4 files changed, 337 insertions(+), 0 deletions(-)
create mode 100644 Documentation/devicetree/bindings/net/can/cc770.txt
create mode 100644 drivers/net/can/cc770/cc770_platform.c
diff --git a/Documentation/devicetree/bindings/net/can/cc770.txt b/Documentation/devicetree/bindings/net/can/cc770.txt
new file mode 100644
index 0000000..01e282d
--- /dev/null
+++ b/Documentation/devicetree/bindings/net/can/cc770.txt
@@ -0,0 +1,56 @@
+Memory mapped Bosch CC770 and Intel AN82527 CAN controller
+
+Note: The CC770 is a CAN controller from Bosch, which is 100%
+compatible with the old AN82527 from Intel, but with "bugs" being fixed.
+
+Required properties:
+
+- compatible : should be "bosch,cc770" for the CC770 and "intc,82527"
+ for the AN82527.
+
+- reg : should specify the chip select, address offset and size required
+ to map the registers of the controller. The size is usually 0x80.
+
+- interrupts : property with a value describing the interrupt source
+ (number and sensitivity) required for the controller.
+
+Optional properties:
+
+- bosch,external-clock-frequency : frequency of the external oscillator
+ clock in Hz. Note that the internal clock frequency used by the
+ controller is half of that value. If not specified, a default
+ value of 16000000 (16 MHz) is used.
+
+- bosch,clock-out-frequency : slock frequency in Hz on the CLKOUT pin.
+ If not specified or if the specified value is 0, the CLKOUT pin
+ will be disabled.
+
+- bosch,slew-rate : slew rate of the CLKOUT signal. If not specified,
+ a resonable value will be calculated.
+
+- bosch,disconnect-rx0-input : see data sheet.
+
+- bosch,disconnect-rx1-input : see data sheet.
+
+- bosch,disconnect-tx1-output : see data sheet.
+
+- bosch,polarity-dominant : see data sheet.
+
+- bosch,divide-memory-clock : see data sheet.
+
+- bosch,iso-low-speed-mux : see data sheet.
+
+For further information, please have a look to the CC770 or AN82527.
+
+Examples:
+
+can at 3,100 {
+ compatible = "bosch,cc770";
+ reg = <3 0x100 0x80>;
+ interrupts = <2 0>;
+ interrupt-parent = <&mpic>;
+ bosch,external-clock-frequency = <16000000>;
+};
+
+
+
diff --git a/drivers/net/can/cc770/Kconfig b/drivers/net/can/cc770/Kconfig
index 28e4d48..22c07a8 100644
--- a/drivers/net/can/cc770/Kconfig
+++ b/drivers/net/can/cc770/Kconfig
@@ -11,4 +11,11 @@ config CAN_CC770_ISA
connected to the ISA bus using I/O port, memory mapped or
indirect access.
+config CAN_CC770_PLATFORM
+ tristate "Generic Platform Bus based CC770 driver"
+ ---help---
+ This driver adds support for the CC770 and AN82527 chips
+ connected to the "platform bus" (Linux abstraction for directly
+ to the processor attached devices).
+
endif
diff --git a/drivers/net/can/cc770/Makefile b/drivers/net/can/cc770/Makefile
index 872ecff..9fb8321 100644
--- a/drivers/net/can/cc770/Makefile
+++ b/drivers/net/can/cc770/Makefile
@@ -4,5 +4,6 @@
obj-$(CONFIG_CAN_CC770) += cc770.o
obj-$(CONFIG_CAN_CC770_ISA) += cc770_isa.o
+obj-$(CONFIG_CAN_CC770_PLATFORM) += cc770_platform.o
ccflags-$(CONFIG_CAN_DEBUG_DEVICES) := -DDEBUG
diff --git a/drivers/net/can/cc770/cc770_platform.c b/drivers/net/can/cc770/cc770_platform.c
new file mode 100644
index 0000000..fb87b22
--- /dev/null
+++ b/drivers/net/can/cc770/cc770_platform.c
@@ -0,0 +1,273 @@
+/*
+ * Driver for CC770 and AN82527 CAN controllers on the platform bus
+ *
+ * Copyright (C) 2009, 2011 Wolfgang Grandegger <wg at 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.
+ */
+
+/*
+ * If platform data are used you should have similar definitions
+ * in your board-specific code:
+ *
+ * static struct cc770_platform_data myboard_cc770_pdata = {
+ * .osc_freq = 16000000,
+ * .cir = 0x41,
+ * .cor = 0x20,
+ * .bcr = 0x40,
+ * };
+ *
+ * Please see include/linux/can/platform/cc770.h for description of
+ * above fields.
+ *
+ * If the device tree is used, you need a CAN node definition in your
+ * DTS file similar to:
+ *
+ * can at 3,100 {
+ * compatible = "bosch,cc770";
+ * reg = <3 0x100 0x80>;
+ * interrupts = <2 0>;
+ * interrupt-parent = <&mpic>;
+ * bosch,external-clock-frequency = <16000000>;
+ * };
+ *
+ * See "Documentation/devicetree/bindings/net/can/cc770.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/can/platform/cc770.h>
+
+#include <linux/of_platform.h>
+
+#include "cc770.h"
+
+#define DRV_NAME "cc770_platform"
+
+MODULE_AUTHOR("Wolfgang Grandegger <wg at grandegger.com>");
+MODULE_DESCRIPTION("Socket-CAN driver for CC770 on the platform bus");
+MODULE_LICENSE("GPL v2");
+
+#define CC770_PLATFORM_CAN_CLOCK 16000000
+
+static u8 cc770_platform_read_reg(const struct cc770_priv *priv, int reg)
+{
+ return in_8(priv->reg_base + reg);
+}
+
+static void cc770_platform_write_reg(const struct cc770_priv *priv, int reg,
+ u8 val)
+{
+ out_8(priv->reg_base + reg, val);
+}
+
+static int __devinit cc770_get_of_node_data(struct platform_device *pdev,
+ struct cc770_priv *priv)
+{
+ struct device_node *np = pdev->dev.of_node;
+ const u32 *prop;
+ int prop_size;
+ u32 clkext;
+
+ prop = of_get_property(np, "bosch,external-clock-frequency",
+ &prop_size);
+ if (prop && (prop_size == sizeof(u32)))
+ clkext = *prop;
+ else
+ clkext = CC770_PLATFORM_CAN_CLOCK; /* default */
+ priv->can.clock.freq = clkext;
+
+ /* The system clock may not exceed 10 MHz */
+ if (priv->can.clock.freq > 10000000) {
+ priv->cpu_interface |= CPUIF_DSC;
+ priv->can.clock.freq /= 2;
+ }
+
+ /* The memory clock may not exceed 8 MHz */
+ if (priv->can.clock.freq > 8000000)
+ priv->cpu_interface |= CPUIF_DMC;
+
+ if (of_get_property(np, "bosch,divide-memory-clock", NULL))
+ priv->cpu_interface |= CPUIF_DMC;
+ if (of_get_property(np, "bosch,iso-low-speed-mux", NULL))
+ priv->cpu_interface |= CPUIF_MUX;
+
+ if (!of_get_property(np, "bosch,no-comperator-bypass", NULL))
+ priv->bus_config |= BUSCFG_CBY;
+ if (of_get_property(np, "bosch,disconnect-rx0-input", NULL))
+ priv->bus_config |= BUSCFG_DR0;
+ if (of_get_property(np, "bosch,disconnect-rx1-input", NULL))
+ priv->bus_config |= BUSCFG_DR1;
+ if (of_get_property(np, "bosch,disconnect-tx1-output", NULL))
+ priv->bus_config |= BUSCFG_DT1;
+ if (of_get_property(np, "bosch,polarity-dominant", NULL))
+ priv->bus_config |= BUSCFG_POL;
+
+ prop = of_get_property(np, "bosch,clock-out-frequency", &prop_size);
+ if (prop && (prop_size == sizeof(u32)) && *prop > 0) {
+ u32 cdv = clkext / *prop;
+ int slew;
+
+ if (cdv > 0 && cdv < 16) {
+ priv->cpu_interface |= CPUIF_CEN;
+ priv->clkout |= (cdv - 1) & CLKOUT_CD_MASK;
+
+ prop = of_get_property(np, "bosch,slew-rate",
+ &prop_size);
+ if (prop && (prop_size == sizeof(u32))) {
+ slew = *prop;
+ } else {
+ /* Determine default slew rate */
+ slew = (CLKOUT_SL_MASK >>
+ CLKOUT_SL_SHIFT) -
+ ((cdv * clkext - 1) / 8000000);
+ if (slew < 0)
+ slew = 0;
+ }
+ priv->clkout |= (slew << CLKOUT_SL_SHIFT) &
+ CLKOUT_SL_MASK;
+ } else {
+ dev_dbg(&pdev->dev, "invalid clock-out-frequency\n");
+ }
+ }
+
+ return 0;
+}
+
+static int __devinit cc770_get_platform_data(struct platform_device *pdev,
+ struct cc770_priv *priv)
+{
+
+ struct cc770_platform_data *pdata = pdev->dev.platform_data;
+
+ priv->can.clock.freq = pdata->osc_freq;
+ if (priv->cpu_interface | CPUIF_DSC)
+ priv->can.clock.freq /= 2;
+ priv->clkout = pdata->cor;
+ priv->bus_config = pdata->bcr;
+ priv->cpu_interface = pdata->cir;
+
+ return 0;
+}
+
+static int __devinit cc770_platform_probe(struct platform_device *pdev)
+{
+ struct net_device *dev;
+ struct cc770_priv *priv;
+ struct resource *mem;
+ resource_size_t mem_size;
+ void __iomem *base;
+ int err, irq;
+
+ mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ irq = platform_get_irq(pdev, 0);
+ if (!mem || irq <= 0)
+ return -ENODEV;
+
+ mem_size = resource_size(mem);
+ if (!request_mem_region(mem->start, mem_size, pdev->name))
+ return -EBUSY;
+
+ base = ioremap(mem->start, mem_size);
+ if (!base) {
+ err = -ENOMEM;
+ goto exit_release_mem;
+ }
+
+ dev = alloc_cc770dev(0);
+ if (!dev) {
+ err = -ENOMEM;
+ goto exit_unmap_mem;
+ }
+
+ dev->irq = irq;
+ priv = netdev_priv(dev);
+ priv->read_reg = cc770_platform_read_reg;
+ priv->write_reg = cc770_platform_write_reg;
+ priv->irq_flags = IRQF_SHARED;
+ priv->reg_base = base;
+
+ if (pdev->dev.of_node)
+ err = cc770_get_of_node_data(pdev, priv);
+ else if (pdev->dev.platform_data)
+ err = cc770_get_platform_data(pdev, priv);
+ else
+ err = -ENODEV;
+ if (err)
+ goto exit_free_cc770;
+
+ dev_dbg(&pdev->dev,
+ "reg_base=0x%p irq=%d clock=%d cpu_interface=0x%02x "
+ "bus_config=0x%02x clkout=0x%02x\n",
+ priv->reg_base, dev->irq, priv->can.clock.freq,
+ priv->cpu_interface, priv->bus_config, priv->clkout);
+
+ dev_set_drvdata(&pdev->dev, dev);
+ SET_NETDEV_DEV(dev, &pdev->dev);
+
+ err = register_cc770dev(dev);
+ if (err) {
+ dev_err(&pdev->dev,
+ "couldn't register CC700 device (err=%d)\n", err);
+ goto exit_free_cc770;
+ }
+
+ return 0;
+
+exit_free_cc770:
+ free_cc770dev(dev);
+exit_unmap_mem:
+ iounmap(base);
+exit_release_mem:
+ release_mem_region(mem->start, mem_size);
+
+ return err;
+}
+
+static int __devexit cc770_platform_remove(struct platform_device *pdev)
+{
+ struct net_device *dev = dev_get_drvdata(&pdev->dev);
+ struct cc770_priv *priv = netdev_priv(dev);
+ struct resource *mem;
+
+ unregister_cc770dev(dev);
+ iounmap(priv->reg_base);
+ free_cc770dev(dev);
+
+ mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ release_mem_region(mem->start, resource_size(mem));
+
+ return 0;
+}
+
+static struct of_device_id __devinitdata cc770_platform_table[] = {
+ {.compatible = "bosch,cc770"}, /* CC770 from Bosch */
+ {.compatible = "intc,82527"}, /* AN82527 from Intel CP */
+ {},
+};
+
+static struct platform_driver cc770_platform_driver = {
+ .driver = {
+ .name = DRV_NAME,
+ .owner = THIS_MODULE,
+ .of_match_table = cc770_platform_table,
+ },
+ .probe = cc770_platform_probe,
+ .remove = __devexit_p(cc770_platform_remove),
+};
+
+module_platform_driver(cc770_platform_driver);
+
--
1.7.4.1
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