From e553f182d55bd268fea3f106368e2344141c212a Mon Sep 17 00:00:00 2001 From: Michael Hennerich Date: Thu, 1 Mar 2012 10:51:03 +0100 Subject: [PATCH] staging: iio: core: Introduce debugfs support, add support for direct register access Changes since V1: Exclude iio debugfs code in case CONFIG_DEBUG_FS isn't enabled. Introduce helper function iio_get_debugfs_dentry. Document additions to struct iio_dev iio_debugfs_read_reg: Use snprintf. Use a shorter fixed length. Introduce len instead of pointer math. iio_debugfs_write_reg: Fix return value use PT_ERR. Changes since V2: Use debugfs_remove. Fix whitespace damage. Signed-off-by: Michael Hennerich Acked-by: Jonathan Cameron Signed-off-by: Greg Kroah-Hartman --- drivers/staging/iio/iio.h | 27 ++++- drivers/staging/iio/industrialio-core.c | 137 +++++++++++++++++++++++- 2 files changed, 162 insertions(+), 2 deletions(-) diff --git a/drivers/staging/iio/iio.h b/drivers/staging/iio/iio.h index 6aa31e52c26d..b9cd454f69e2 100644 --- a/drivers/staging/iio/iio.h +++ b/drivers/staging/iio/iio.h @@ -286,6 +286,9 @@ struct iio_info { struct iio_trigger *trig); int (*update_scan_mode)(struct iio_dev *indio_dev, const unsigned long *scan_mask); + int (*debugfs_reg_access)(struct iio_dev *indio_dev, + unsigned reg, unsigned writeval, + unsigned *readval); }; /** @@ -332,7 +335,9 @@ struct iio_buffer_setup_ops { * @groups: [INTERN] attribute groups * @groupcounter: [INTERN] index of next attribute group * @flags: [INTERN] file ops related flags including busy flag. - **/ + * @debugfs_dentry: [INTERN] device specific debugfs dentry. + * @cached_reg_addr: [INTERN] cached register address for debugfs reads. + */ struct iio_dev { int id; @@ -366,6 +371,10 @@ struct iio_dev { int groupcounter; unsigned long flags; +#if defined(CONFIG_DEBUG_FS) + struct dentry *debugfs_dentry; + unsigned cached_reg_addr; +#endif }; /** @@ -443,4 +452,20 @@ static inline bool iio_buffer_enabled(struct iio_dev *indio_dev) & (INDIO_BUFFER_TRIGGERED | INDIO_BUFFER_HARDWARE); }; +/** + * iio_get_debugfs_dentry() - helper function to get the debugfs_dentry + * @indio_dev: IIO device info structure for device + **/ +#if defined(CONFIG_DEBUG_FS) +static inline struct dentry *iio_get_debugfs_dentry(struct iio_dev *indio_dev) +{ + return indio_dev->debugfs_dentry; +}; +#else +static inline struct dentry *iio_get_debugfs_dentry(struct iio_dev *indio_dev) +{ + return NULL; +}; +#endif + #endif /* _INDUSTRIAL_IO_H_ */ diff --git a/drivers/staging/iio/industrialio-core.c b/drivers/staging/iio/industrialio-core.c index 0b8ba8f1483b..868e36672001 100644 --- a/drivers/staging/iio/industrialio-core.c +++ b/drivers/staging/iio/industrialio-core.c @@ -22,6 +22,7 @@ #include #include #include +#include #include "iio.h" #include "iio_core.h" #include "iio_core_trigger.h" @@ -39,6 +40,8 @@ struct bus_type iio_bus_type = { }; EXPORT_SYMBOL(iio_bus_type); +static struct dentry *iio_debugfs_dentry; + static const char * const iio_data_type_name[] = { [IIO_RAW] = "raw", [IIO_PROCESSED] = "input", @@ -129,6 +132,8 @@ static int __init iio_init(void) goto error_unregister_bus_type; } + iio_debugfs_dentry = debugfs_create_dir("iio", NULL); + return 0; error_unregister_bus_type: @@ -142,6 +147,84 @@ static void __exit iio_exit(void) if (iio_devt) unregister_chrdev_region(iio_devt, IIO_DEV_MAX); bus_unregister(&iio_bus_type); + debugfs_remove(iio_debugfs_dentry); +} + +#if defined(CONFIG_DEBUG_FS) +static int iio_debugfs_open(struct inode *inode, struct file *file) +{ + if (inode->i_private) + file->private_data = inode->i_private; + + return 0; +} + +static ssize_t iio_debugfs_read_reg(struct file *file, char __user *userbuf, + size_t count, loff_t *ppos) +{ + struct iio_dev *indio_dev = file->private_data; + char buf[20]; + unsigned val = 0; + ssize_t len; + int ret; + + ret = indio_dev->info->debugfs_reg_access(indio_dev, + indio_dev->cached_reg_addr, + 0, &val); + if (ret) + dev_err(indio_dev->dev.parent, "%s: read failed\n", __func__); + + len = snprintf(buf, sizeof(buf), "0x%X\n", val); + + return simple_read_from_buffer(userbuf, count, ppos, buf, len); +} + +static ssize_t iio_debugfs_write_reg(struct file *file, + const char __user *userbuf, size_t count, loff_t *ppos) +{ + struct iio_dev *indio_dev = file->private_data; + unsigned reg, val; + char buf[80]; + int ret; + + count = min_t(size_t, count, (sizeof(buf)-1)); + if (copy_from_user(buf, userbuf, count)) + return -EFAULT; + + buf[count] = 0; + + ret = sscanf(buf, "%i %i", ®, &val); + + switch (ret) { + case 1: + indio_dev->cached_reg_addr = reg; + break; + case 2: + indio_dev->cached_reg_addr = reg; + ret = indio_dev->info->debugfs_reg_access(indio_dev, reg, + val, NULL); + if (ret) { + dev_err(indio_dev->dev.parent, "%s: write failed\n", + __func__); + return ret; + } + break; + default: + return -EINVAL; + } + + return count; +} + +static const struct file_operations iio_debugfs_reg_fops = { + .open = iio_debugfs_open, + .read = iio_debugfs_read_reg, + .write = iio_debugfs_write_reg, +}; + +static void iio_device_unregister_debugfs(struct iio_dev *indio_dev) +{ + debugfs_remove_recursive(indio_dev->debugfs_dentry); } static ssize_t iio_read_channel_ext_info(struct device *dev, @@ -171,6 +254,49 @@ static ssize_t iio_write_channel_ext_info(struct device *dev, return ext_info->write(indio_dev, this_attr->c, buf, len); } +static int iio_device_register_debugfs(struct iio_dev *indio_dev) +{ + struct dentry *d; + + if (indio_dev->info->debugfs_reg_access == NULL) + return 0; + + if (IS_ERR(iio_debugfs_dentry)) + return 0; + + indio_dev->debugfs_dentry = + debugfs_create_dir(dev_name(&indio_dev->dev), + iio_debugfs_dentry); + if (IS_ERR(indio_dev->debugfs_dentry)) + return PTR_ERR(indio_dev->debugfs_dentry); + + if (indio_dev->debugfs_dentry == NULL) { + dev_warn(indio_dev->dev.parent, + "Failed to create debugfs directory\n"); + return -EFAULT; + } + + d = debugfs_create_file("direct_reg_access", 0644, + indio_dev->debugfs_dentry, + indio_dev, &iio_debugfs_reg_fops); + if (!d) { + iio_device_unregister_debugfs(indio_dev); + return -ENOMEM; + } + + return 0; +} +#else +static int iio_device_register_debugfs(struct iio_dev *indio_dev) +{ + return 0; +} + +static void iio_device_unregister_debugfs(struct iio_dev *indio_dev) +{ +} +#endif /* CONFIG_DEBUG_FS */ + static ssize_t iio_read_channel_info(struct device *dev, struct device_attribute *attr, char *buf) @@ -618,6 +744,7 @@ static void iio_dev_release(struct device *device) iio_device_unregister_trigger_consumer(indio_dev); iio_device_unregister_eventset(indio_dev); iio_device_unregister_sysfs(indio_dev); + iio_device_unregister_debugfs(indio_dev); } static struct device_type iio_dev_type = { @@ -734,11 +861,17 @@ int iio_device_register(struct iio_dev *indio_dev) /* configure elements for the chrdev */ indio_dev->dev.devt = MKDEV(MAJOR(iio_devt), indio_dev->id); + ret = iio_device_register_debugfs(indio_dev); + if (ret) { + dev_err(indio_dev->dev.parent, + "Failed to register debugfs interfaces\n"); + goto error_ret; + } ret = iio_device_register_sysfs(indio_dev); if (ret) { dev_err(indio_dev->dev.parent, "Failed to register sysfs interfaces\n"); - goto error_ret; + goto error_unreg_debugfs; } ret = iio_device_register_eventset(indio_dev); if (ret) { @@ -765,6 +898,8 @@ error_unreg_eventset: iio_device_unregister_eventset(indio_dev); error_free_sysfs: iio_device_unregister_sysfs(indio_dev); +error_unreg_debugfs: + iio_device_unregister_debugfs(indio_dev); error_ret: return ret; } -- 2.30.2