ucmb: Experimental SPI-GPIO based communication channel
authorMichael Büsch <mb@bu3sch.de>
Wed, 11 Feb 2009 18:56:51 +0000 (18:56 +0000)
committerMichael Büsch <mb@bu3sch.de>
Wed, 11 Feb 2009 18:56:51 +0000 (18:56 +0000)
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@14478 3c298f89-4303-0410-b956-a3cf2f4a3e73

package/ucmb/Makefile [new file with mode: 0644]
package/ucmb/src/Makefile [new file with mode: 0644]
package/ucmb/src/ucmb.c [new file with mode: 0644]
package/ucmb/src/ucmb.h [new file with mode: 0644]

diff --git a/package/ucmb/Makefile b/package/ucmb/Makefile
new file mode 100644 (file)
index 0000000..b0b569e
--- /dev/null
@@ -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 (file)
index 0000000..a232a4a
--- /dev/null
@@ -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 (file)
index 0000000..4807f95
--- /dev/null
@@ -0,0 +1,328 @@
+/*
+ * Microcontroller Message Bus
+ *
+ * Copyright (c) 2009 Michael Buesch <mb@bu3sch.de>
+ *
+ * Licensed under the GNU/GPL. See COPYING for details.
+ */
+
+#include "ucmb.h"
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/miscdevice.h>
+#include <linux/fs.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/spi_gpio.h>
+#include <linux/spi/spi_bitbang.h>
+#include <linux/gfp.h>
+
+
+#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 (file)
index 0000000..f1a9283
--- /dev/null
@@ -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_ */