From: Michael Büsch Date: Wed, 11 Feb 2009 18:56:51 +0000 (+0000) Subject: ucmb: Experimental SPI-GPIO based communication channel X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=df77d3b06d061404cf3210c4da185b65f77e42e6;p=openwrt%2Fstaging%2Frobimarko.git ucmb: Experimental SPI-GPIO based communication channel SVN-Revision: 14478 --- diff --git a/package/ucmb/Makefile b/package/ucmb/Makefile new file mode 100644 index 0000000000..b0b569ebc8 --- /dev/null +++ b/package/ucmb/Makefile @@ -0,0 +1,39 @@ +# +# Copyright (C) 2009 OpenWrt.org +# +# This is free software, licensed under the GNU General Public License v2. +# See /LICENSE for more information. + +include $(TOPDIR)/rules.mk +include $(INCLUDE_DIR)/kernel.mk + +PKG_NAME:=ucmb +PKG_RELEASE:=1 + +include $(INCLUDE_DIR)/package.mk + +define KernelPackage/ucmb + SUBMENU:=Other modules + DEPENDS:=@LINUX_2_6 +kmod-spi-gpio + KCONFIG:=CONFIG_SPI=y \ + CONFIG_SPI_MASTER=y + TITLE:=Microcontroller Message Bus (EXPERIMENTAL) + FILES:=$(PKG_BUILD_DIR)/ucmb.$(LINUX_KMOD_SUFFIX) + AUTOLOAD:=$(call AutoLoad,93,ucmb) +endef + +define Build/Prepare + mkdir -p $(PKG_BUILD_DIR) + $(CP) ./src/* $(PKG_BUILD_DIR)/ +endef + +define Build/Compile + $(MAKE) -C "$(LINUX_DIR)" \ + CROSS_COMPILE="$(TARGET_CROSS)" \ + ARCH="$(LINUX_KARCH)" \ + SUBDIRS="$(PKG_BUILD_DIR)" \ + EXTRA_CFLAGS="$(BUILDFLAGS)" \ + modules +endef + +$(eval $(call KernelPackage,ucmb)) diff --git a/package/ucmb/src/Makefile b/package/ucmb/src/Makefile new file mode 100644 index 0000000000..a232a4a096 --- /dev/null +++ b/package/ucmb/src/Makefile @@ -0,0 +1 @@ +obj-m := ucmb.o diff --git a/package/ucmb/src/ucmb.c b/package/ucmb/src/ucmb.c new file mode 100644 index 0000000000..4807f95ce3 --- /dev/null +++ b/package/ucmb/src/ucmb.c @@ -0,0 +1,328 @@ +/* + * Microcontroller Message Bus + * + * Copyright (c) 2009 Michael Buesch + * + * Licensed under the GNU/GPL. See COPYING for details. + */ + +#include "ucmb.h" + +#include +#include +#include +#include +#include +#include +#include +#include + + +#define PFX "ucmb: " + + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Microcontroller Message Bus"); +MODULE_AUTHOR("Michael Buesch"); + + +struct ucmb { + /* Misc character device driver */ + struct miscdevice mdev; + struct file_operations mdev_fops; + + /* SPI driver */ + struct spi_device *sdev; + + /* SPI-GPIO driver */ + struct spi_gpio_platform_data spi_gpio_pdata; + struct platform_device spi_gpio_pdev; +}; + +static int ucmb_spi_busnum_count = 1337; + + +static struct ucmb_platform_data ucmb_list[] = { + { //FIXME don't define it here. + .name = "ucmb", + .gpio_sck = 0, + .gpio_miso = 1, + .gpio_mosi = 2, + }, +}; + + +static int __devinit ucmb_spi_probe(struct spi_device *sdev) +{ + return 0; +} + +static int __devexit ucmb_spi_remove(struct spi_device *sdev) +{ + return 0; +} + +static struct spi_driver ucmb_spi_driver = { + .driver = { + .name = "ucmb", + .bus = &spi_bus_type, + .owner = THIS_MODULE, + }, + .probe = ucmb_spi_probe, + .remove = __devexit_p(ucmb_spi_remove), +}; + +static inline struct ucmb * filp_to_ucmb(struct file *filp) +{ + return container_of(filp->f_op, struct ucmb, mdev_fops); +} + +/* FIXME offp */ +static ssize_t ucmb_read(struct file *filp, char __user *user_buf, + size_t size, loff_t *offp) +{ + struct ucmb *ucmb = filp_to_ucmb(filp); + u8 *buf; + int err; + + err = -E2BIG; + if (size > PAGE_SIZE) + goto out; + + err = -ENOMEM; + buf = (char *)__get_free_page(GFP_KERNEL); + if (!buf) + goto out; + + err = spi_read(ucmb->sdev, buf, size); + if (err) + goto out_free; + + err = -EFAULT; + if (copy_to_user(user_buf, buf, size)) + goto out_free; + + err = 0; + +out_free: + __free_page((unsigned long)buf); +out: + return err ? err : size; +} + +/* FIXME offp */ +static ssize_t ucmb_write(struct file *filp, const char __user *user_buf, + size_t size, loff_t *offp) +{ + struct ucmb *ucmb = filp_to_ucmb(filp); + u8 *buf; + int err; + + err = -ENOMEM; + buf = (char *)__get_free_page(GFP_KERNEL); + if (!buf) + goto out; + + size = min(PAGE_SIZE, size); + err = -EFAULT; + if (copy_from_user(buf, user_buf, size)) + goto out_free; + + err = spi_write(ucmb->sdev, buf, size); + +out_free: + __free_page((unsigned long)buf); +out: + return err ? err : size; +} + +static int __devinit ucmb_probe(struct platform_device *pdev) +{ + struct ucmb_platform_data *pdata; + struct ucmb *ucmb; + int err; + const int bus_num = ucmb_spi_busnum_count++; + struct spi_bitbang *bb; + + pdata = pdev->dev.platform_data; + if (!pdata) + return -ENXIO; + + ucmb = kzalloc(sizeof(struct ucmb), GFP_KERNEL); + if (!ucmb) + return -ENOMEM; + + /* Create the SPI GPIO bus master. */ + +#ifdef CONFIG_SPI_GPIO_MODULE + err = request_module("spi_gpio"); + if (err) + printk(KERN_WARNING PFX "Failed to request spi_gpio module\n"); +#endif /* CONFIG_SPI_GPIO_MODULE */ + + ucmb->spi_gpio_pdata.sck = pdata->gpio_sck; + ucmb->spi_gpio_pdata.mosi = pdata->gpio_mosi; + ucmb->spi_gpio_pdata.miso = pdata->gpio_miso; + ucmb->spi_gpio_pdata.num_chipselect = 1; + + ucmb->spi_gpio_pdev.name = "spi_gpio"; + ucmb->spi_gpio_pdev.id = bus_num; + ucmb->spi_gpio_pdev.dev.platform_data = &ucmb->spi_gpio_pdata; + + err = platform_device_register(&ucmb->spi_gpio_pdev); + if (err) { + printk(KERN_ERR PFX "Failed to register SPI-GPIO platform device\n"); + goto err_free_ucmb; + } + bb = platform_get_drvdata(&ucmb->spi_gpio_pdev); + if (!bb || !bb->master) { + printk(KERN_ERR PFX "No bitbanged master device found.\n"); + goto err_unreg_spi_gpio_pdev; + } + + /* Create the SPI device. */ + + ucmb->sdev = spi_alloc_device(bb->master); + if (!ucmb->sdev) { + printk(KERN_ERR PFX "Failed to allocate SPI device\n"); + goto err_unreg_spi_gpio_pdev; + } + ucmb->sdev->max_speed_hz = 5000000; + ucmb->sdev->chip_select = 0; + ucmb->sdev->mode = SPI_MODE_0; + strlcpy(ucmb->sdev->modalias, "ucmb", /* We are the SPI driver. */ + sizeof(ucmb->sdev->modalias)); + ucmb->sdev->controller_data = (void *)SPI_GPIO_NO_CHIPSELECT; + err = spi_add_device(ucmb->sdev); + if (err) { + printk(KERN_ERR PFX "Failed to add SPI device\n"); + goto err_free_spi_device; + } + + /* Create the Misc char device. */ + + ucmb->mdev.minor = MISC_DYNAMIC_MINOR; + ucmb->mdev.name = pdata->name; + ucmb->mdev.parent = &pdev->dev; + ucmb->mdev_fops.read = ucmb_read; + ucmb->mdev_fops.write = ucmb_write; + ucmb->mdev.fops = &ucmb->mdev_fops; + + err = misc_register(&ucmb->mdev); + if (err) { + printk(KERN_ERR PFX "Failed to register miscdev %s\n", + ucmb->mdev.name); + goto err_unreg_spi_device; + } + + platform_set_drvdata(pdev, ucmb); + + printk(KERN_INFO PFX "Registered message bus \"%s\"\n", pdata->name); + + return 0; + +err_unreg_spi_device: + spi_unregister_device(ucmb->sdev); +err_free_spi_device: + spi_dev_put(ucmb->sdev); +err_unreg_spi_gpio_pdev: + platform_device_unregister(&ucmb->spi_gpio_pdev); +err_free_ucmb: + kfree(ucmb); + + return err; +} + +static int __devexit ucmb_remove(struct platform_device *pdev) +{ + struct ucmb *ucmb = platform_get_drvdata(pdev); + int err; + + err = misc_deregister(&ucmb->mdev); + if (err) { + printk(KERN_ERR PFX "Failed to unregister miscdev %s\n", + ucmb->mdev.name); + } + spi_unregister_device(ucmb->sdev); + spi_dev_put(ucmb->sdev); + platform_device_unregister(&ucmb->spi_gpio_pdev); + + kfree(ucmb); + platform_set_drvdata(pdev, NULL); + + return 0; +} + +static struct platform_driver ucmb_driver = { + .driver = { + .name = "ucmb", + .owner = THIS_MODULE, + }, + .probe = ucmb_probe, + .remove = __devexit_p(ucmb_probe), +}; + +static int ucmb_modinit(void) +{ + struct ucmb_platform_data *pdata; + struct platform_device *pdev; + int err, i; + + printk(KERN_INFO "Microcontroller message bus driver\n"); + + err = platform_driver_register(&ucmb_driver); + if (err) { + printk(KERN_ERR PFX "Failed to register platform driver\n"); + return err; + } + err = spi_register_driver(&ucmb_spi_driver); + if (err) { + printk(KERN_ERR PFX "Failed to register SPI driver\n"); + platform_driver_unregister(&ucmb_driver); + return err; + } + + for (i = 0; i < ARRAY_SIZE(ucmb_list); i++) { + pdata = &ucmb_list[i]; + + pdev = platform_device_alloc("ucmb", i); + if (!pdev) { + printk(KERN_ERR PFX "Failed to allocate platform device.\n"); + break; + } + err = platform_device_add_data(pdev, pdata, sizeof(*pdata)); + if (err) { + printk(KERN_ERR PFX "Failed to add platform data.\n"); + platform_device_put(pdev); + break; + } + err = platform_device_add(pdev); + if (err) { + printk(KERN_ERR PFX "Failed to register platform device.\n"); + platform_device_put(pdev); + break; + } + pdata->pdev = pdev; + } + + return 0; +} +module_init(ucmb_modinit); + +static void ucmb_modexit(void) +{ + struct ucmb_platform_data *pdata; + int i; + + for (i = 0; i < ARRAY_SIZE(ucmb_list); i++) { + pdata = &ucmb_list[i]; + + if (pdata->pdev) { + platform_device_unregister(pdata->pdev); + platform_device_put(pdata->pdev); + } + } + spi_unregister_driver(&ucmb_spi_driver); + platform_driver_unregister(&ucmb_driver); +} +module_exit(ucmb_modexit); diff --git a/package/ucmb/src/ucmb.h b/package/ucmb/src/ucmb.h new file mode 100644 index 0000000000..f1a92836f8 --- /dev/null +++ b/package/ucmb/src/ucmb.h @@ -0,0 +1,13 @@ +#ifndef LINUX_UCMB_H_ +#define LINUX_UCMB_H_ + +struct ucmb_platform_data { + const char *name; + unsigned int gpio_sck; + unsigned int gpio_miso; + unsigned int gpio_mosi; + + struct platform_device *pdev; /* internal */ +}; + +#endif /* LINUX_UCMB_H_ */