From e285e44d91fe5a89e0d9fe4f5dda4f9e8c8a3c7e Mon Sep 17 00:00:00 2001 From: Wolfgang Grandegger Date: Wed, 30 Nov 2011 23:41:20 +0000 Subject: [PATCH] can: cc770: add platform bus driver for the CC770 and AN82527 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 Signed-off-by: Wolfgang Grandegger Acked-by: Marc Kleine-Budde Signed-off-by: David S. Miller --- .../devicetree/bindings/net/can/cc770.txt | 53 ++++ drivers/net/can/cc770/Kconfig | 7 + drivers/net/can/cc770/Makefile | 1 + drivers/net/can/cc770/cc770_platform.c | 272 ++++++++++++++++++ 4 files changed, 333 insertions(+) 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 000000000000..77027bf6460a --- /dev/null +++ b/Documentation/devicetree/bindings/net/can/cc770.txt @@ -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>; +}; diff --git a/drivers/net/can/cc770/Kconfig b/drivers/net/can/cc770/Kconfig index 28e4d4810f44..22c07a8c8b43 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 872ecffa80b7..9fb8321b33eb 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 000000000000..53115eee8075 --- /dev/null +++ b/drivers/net/can/cc770/cc770_platform.c @@ -0,0 +1,272 @@ +/* + * Driver for CC770 and AN82527 CAN controllers on the platform bus + * + * Copyright (C) 2009, 2011 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. + */ + +/* + * 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "cc770.h" + +#define DRV_NAME "cc770_platform" + +MODULE_AUTHOR("Wolfgang Grandegger "); +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);