diff options
| -rw-r--r-- | 1/config.h | 11 | ||||
| -rw-r--r-- | 1/fopdrv.c | 20 |
2 files changed, 29 insertions, 2 deletions
@@ -2,3 +2,14 @@ #define DRV_NAME "lork" +#include <linux/types.h> + +// values from <https://www.ti.com/lit/ug/spruh73q/spruh73q.pdf> + +typedef uint32_t ti_am335x_word_t; + +// p. 180: "Control Module" +#define TI_AM335X_CM_ADDR ((ti_am335x_word_t*) 0x44E1_0000) +// p. 1459: "conf_gpmc_a3" +#define TI_AM335X_CM_GPMC_A3_ADDR ((ti_am335x_word_t*) TI_AM3358_CM_ADDR + 0x84Ch) + @@ -2,13 +2,29 @@ // driver/char/mem.c read_null (/dev/null) ssize_t fop_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) { - printk("%s(<file>, <buf>, %lu, <ppos>)\n", __PRETTY_FUNCTION__, count); + printk("%s(<file>, <buf>, %u, <ppos>)\n", __PRETTY_FUNCTION__, count); return 0; } // driver/char/mem.c write_null ssize_t fop_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { - printk("%s(<file>, <buf>, %lu, <ppos>)\n", __PRETTY_FUNCTION__, count); + printk("%s(<file>, <buf>, %u, <ppos>)\n", __PRETTY_FUNCTION__, count); + + // only allow single character as input + if (count != 1) 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; + + if (input_buf[0] == '0') { + printk("TODO: TURN OFF OUTPUT\n"); + } + if (input_buf[0] == '1') { + printk("TODO: TURN ON OUTPUT\n"); + } + return count; } |