SPEAr320 design contains two boards: a) CPU board (which houses the ARM926ejs CPU and DDR in addition to some other interfaces like USB host etc..) b) Application PLC board (which contains two Bosch CCAN IPs that are interfaced to APB bus in addition to other interfaces like UART etc..) [See details here: http://www.st.com/stonline/products/families/embedded_mpu/spear_mpus/spear320_single_core.htm]
The SPEAr CAN driver relies on 'platform data/board specific details' that are passed by means of relevant evb files present in 'arch/arm/mach-spear3xx' directory. Signed-off-by: Bhupesh Sharma <[email protected]> Index: spear320_can.c =================================================================== --- spear320_can.c (revision 0) +++ spear320_can.c (revision 0) @@ -0,0 +1,203 @@ +/* + * drivers/net/can/spear320_can.c + * + * CAN bus driver for SPEAr320 SoC that houses two independent + * Bosch CCAN controllers. + * + * Copyright (C) 2010 ST Microelectronics + * Bhupesh Sharma <[email protected]> + * + * Borrowed heavily from the original code written for Hynix7202 by: + * - Sascha Hauer, Marc Kleine-Budde, Pengutronix <[email protected]> + * - Simon Kallweit, intefo AG <[email protected]> + * which can be viewed here: + * http://svn.berlios.de/svnroot/repos/socketcan/trunk/kernel/2.6/ + * drivers/net/can/old/ccan/ + * + * TODO: + * - Power Management support to be added + * + * This file is licensed under the terms of the GNU General Public + * License version 2. This program is licensed "as is" without any + * warranty of any kind, whether express or implied. + */ + +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/interrupt.h> +#include <linux/platform_device.h> +#include <linux/netdevice.h> +#include <socketcan/can.h> +#include <socketcan/can/dev.h> + +#include "bosch_ccan.h" + +#define DRV_NAME "spear_can" +#define CAN_ENABLE 0x0e + +static u16 spear320_can_read_reg(const struct bosch_ccan_priv *priv, + enum ccan_regs reg) +{ + u16 val; + + /* shifting 1 place because 16 bit registers are word aligned */ + val = readw(priv->reg_base + (reg << 1)); + return val; +} + +static void spear320_can_write_reg(const struct bosch_ccan_priv *priv, + enum ccan_regs reg, u16 val) +{ + /* shifting 1 place because 16 bit registers are word aligned */ + writew(val, priv->reg_base + (reg << 1)); +} + +static int spear320_can_drv_probe(struct platform_device *pdev) +{ + int ret; + void __iomem *addr; + struct net_device *dev; + struct bosch_ccan_priv *priv; + struct resource *mem, *irq; + struct clk *clk; + + /* get the appropriate clk */ + clk = clk_get(&pdev->dev, NULL); + if (IS_ERR(clk)) { + dev_err(&pdev->dev, "no clock defined\n"); + ret = -ENODEV; + goto exit; + } + + /* get the platform data */ + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); + irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0); + if (!mem || !irq) { + ret = -ENODEV; + goto exit_free_clk; + } + + if (!request_mem_region(mem->start, resource_size(mem), DRV_NAME)) { + dev_err(&pdev->dev, "resource unavailable\n"); + ret = -ENODEV; + goto exit_free_clk; + } + + addr = ioremap(mem->start, resource_size(mem)); + if (!addr) { + dev_err(&pdev->dev, "failed to map can port\n"); + ret = -ENOMEM; + goto exit_release_mem; + } + + /* allocate the ccan device */ + dev = alloc_bosch_ccandev(0); + if (!dev) { + clk_put(clk); + ret = -ENOMEM; + goto exit_iounmap; + } + + priv = netdev_priv(dev); + dev->irq = irq->start; + priv->irq_flags = irq->flags; + priv->reg_base = addr; + priv->can.clock.freq = clk_get_rate(clk); + priv->read_reg = spear320_can_read_reg; + priv->write_reg = spear320_can_write_reg; + priv->clk = clk; + + platform_set_drvdata(pdev, dev); + SET_NETDEV_DEV(dev, &pdev->dev); + + /* register ccan */ + spear320_can_write_reg(priv, CAN_ENABLE, 1); + ret = register_bosch_ccandev(dev); + if (ret) { + dev_err(&pdev->dev, "registering %s failed (err=%d)\n", + DRV_NAME, ret); + goto exit_free_device; + } + + dev_info(&pdev->dev, "%s device registered (reg_base=%p, irq=%d)\n", + DRV_NAME, priv->reg_base, dev->irq); + return 0; + +exit_free_device: + platform_set_drvdata(pdev, NULL); + free_bosch_ccandev(dev); +exit_iounmap: + iounmap(addr); +exit_release_mem: + release_mem_region(mem->start, resource_size(mem)); +exit_free_clk: + clk_put(clk); +exit: + dev_err(&pdev->dev, "probe failed\n"); + + return ret; +} + +static int spear320_can_drv_remove(struct platform_device *pdev) +{ + struct net_device *dev = platform_get_drvdata(pdev); + struct bosch_ccan_priv *priv = netdev_priv(dev); + struct resource *mem; + + unregister_bosch_ccandev(dev); + platform_set_drvdata(pdev, NULL); + + if (priv->reg_base) + iounmap(priv->reg_base); + + clk_put(priv->clk); + + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); + release_mem_region(mem->start, resource_size(mem)); + + free_bosch_ccandev(dev); + + return 0; +} + +#ifdef CONFIG_PM +static int spear320_can_drv_suspend(struct platform_device *pdev, + pm_message_t state) +{ + return 0; +} + +static int spear320_can_drv_resume(struct platform_device *pdev) +{ + return 0; +} +#endif /* CONFIG_PM */ + +static struct platform_driver spear320_can_driver = { + .driver = { + .name = DRV_NAME, + }, + .probe = spear320_can_drv_probe, + .remove = spear320_can_drv_remove, +#ifdef CONFIG_PM + .suspend = spear320_can_drv_suspend, + .resume = spear320_can_drv_resume, +#endif /* CONFIG_PM */ +}; + +static int __init spear320_can_init(void) +{ + return platform_driver_register(&spear320_can_driver); +} +module_init(spear320_can_init); + +static void __exit spear320_can_cleanup(void) +{ + platform_driver_unregister(&spear320_can_driver); +} +module_exit(spear320_can_cleanup); + +MODULE_AUTHOR("Bhupesh Sharma <[email protected]>"); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("CAN bus driver for SPEAr320 which has 2 CCAN controllers"); _______________________________________________ Socketcan-core mailing list [email protected] https://lists.berlios.de/mailman/listinfo/socketcan-core
