can: cc770: add platform bus driver for the CC770 and AN82527
authorWolfgang Grandegger <wg@grandegger.com>
Wed, 30 Nov 2011 23:41:20 +0000 (23:41 +0000)
committerDavid S. Miller <davem@davemloft.net>
Thu, 1 Dec 2011 18:09:31 +0000 (13:09 -0500)
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@lists.ozlabs.org
CC: linuxppc-dev@ozlabs.org
CC: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Wolfgang Grandegger <wg@grandegger.com>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Documentation/devicetree/bindings/net/can/cc770.txt [new file with mode: 0644]
drivers/net/can/cc770/Kconfig
drivers/net/can/cc770/Makefile
drivers/net/can/cc770/cc770_platform.c [new file with mode: 0644]

diff --git a/Documentation/devicetree/bindings/net/can/cc770.txt b/Documentation/devicetree/bindings/net/can/cc770.txt
new file mode 100644 (file)
index 0000000..77027bf
--- /dev/null
@@ -0,0 +1,53 @@
+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@3,100 {
+       compatible = "bosch,cc770";
+       reg = <3 0x100 0x80>;
+       interrupts = <2 0>;
+       interrupt-parent = <&mpic>;
+       bosch,external-clock-frequency = <16000000>;
+};
index 28e4d48..22c07a8 100644 (file)
@@ -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
index 872ecff..9fb8321 100644 (file)
@@ -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 (file)
index 0000000..53115ee
--- /dev/null
@@ -0,0 +1,272 @@
+/*
+ * Driver for CC770 and AN82527 CAN controllers on the platform bus
+ *
+ * Copyright (C) 2009, 2011 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.
+ */
+
+/*
+ * 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@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/platform_device.h>
+#include <linux/of.h>
+#include <linux/can.h>
+#include <linux/can/dev.h>
+#include <linux/can/platform/cc770.h>
+
+#include "cc770.h"
+
+#define DRV_NAME "cc770_platform"
+
+MODULE_AUTHOR("Wolfgang Grandegger <wg@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 ioread8(priv->reg_base + reg);
+}
+
+static void cc770_platform_write_reg(const struct cc770_priv *priv, int reg,
+                                    u8 val)
+{
+       iowrite8(val, priv->reg_base + reg);
+}
+
+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);