diff options
Diffstat (limited to 'driver/fopdrv.c')
-rw-r--r-- | driver/fopdrv.c | 70 |
1 files changed, 0 insertions, 70 deletions
diff --git a/driver/fopdrv.c b/driver/fopdrv.c deleted file mode 100644 index 87aa30e..0000000 --- a/driver/fopdrv.c +++ /dev/null @@ -1,70 +0,0 @@ -#include <linux/io.h> - -#include "fopdrv.h" -#include "config.h" - -bool printed = false; - -// driver/char/mem.c read_null (/dev/null) -ssize_t fop_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) { - if (count < 2) return 0; - if (printed) return 0; - - ti_am335x_word_t* gpio1 = ioremap(TI_AM335X_GPIO1_ADDR, GPIO_REG_SIZE); - barrier(); - - ti_am335x_word_t gpio = ioread32(gpio1 + GPIO_DATAIN); rmb(); - bool on = (gpio & (1<<PIN)) > 0; - - char output[10]; - snprintf(output, 10, "%d\n", on); - - if (copy_to_user(buf, output + *ppos, 2)) - return -EFAULT; - *ppos += 2; - printed = true; - return 2; -} - -ssize_t fop_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { - // only allow single character as input - if (count < 1) return count; - if (count > 2) return count; - - // copy buffer for reading (see [kernel-labs-chrdev] in ../readme.md) - char input_buf[10]; - if (copy_from_user(input_buf + *ppos, buf, count)) - return -EFAULT; - - ti_am335x_word_t* gpio1 = ioremap(TI_AM335X_GPIO1_ADDR, GPIO_REG_SIZE); - barrier(); - - if (input_buf[0] == '0') { - printk(DRV_NAME": OUTPUT OFF\n"); - iowrite32((1<<PIN), gpio1 + GPIO_CLEARDATAOUT); wmb(); - } - if (input_buf[0] == '1') { - printk(DRV_NAME": OUTPUT ON\n"); - iowrite32((1<<PIN), gpio1 + GPIO_SETDATAOUT); wmb(); - } - - iounmap(gpio1); - - return count; -} - -int fop_open(struct inode * inode, struct file * file) { - printed = false; - return 0; - // 0 seems to be a safe return value as it's used in driver/char/mem.c. The - // manual page for open(2) says that the system call returns a nonnegative - // integer representing the file descriptor on success, but it does not - // appears to be required. -} - -int fop_release(struct inode * inode, struct file * file) { - return 0; - // same as above, but found in driver/char/lp.c -} - - |