diff options
Diffstat (limited to 'skey.c')
| -rw-r--r-- | skey.c | 71 |
1 files changed, 41 insertions, 30 deletions
@@ -2,6 +2,9 @@ #include <linux/module.h> #include <linux/gpio.h> #include <linux/timer.h> +#include <linux/kthread.h> +#include <linux/delay.h> +#include <linux/sched.h> /* * Unsigned ints containing the BCM pin numbers for the pins used, __initdata * helps with the loading and unloading of data in memory @@ -14,35 +17,46 @@ static __initdata unsigned int row_pins[3] = {3, 6, 5}; static __initdata char * clabels[10] = {"C0", "C1", "C2", "C3", "C4", "C5", "C6", "C7", "C8", "C9",}; static __initdata char * rlabels[3] = {"R0", "R1", "R2"}; /* - * timer period in ms and timer struct + * variables for setting up the thread */ -static struct timer_list update_timer; -static int update_period = 5; + +struct task_struct *update_task; /* *This function is called every timer-period to actually read the keyboard */ -static void skey_update (unsigned long unused) { - printk(KERN_INFO "skey: updated keyboard\n"); - //reads the keyboard - int row_index = 0; - int column_index = 0; - while (column_index < 10) { - //sets the column pin high for reading - gpio_set_value(column_pins[column_index], 1); - //reads with all the rows - row_index = 0; - while (row_index < 3) { - if (gpio_get_value(row_pins[row_index])) { - printk(KERN_INFO "skey: key pressed at column %d, row %d\n", column_index, row_index); +int skey_update_thread (void *data) { + printk(KERN_INFO "skey: starting update thread\n"); + //thread stuff + const struct sched_param PARAM = { .sched_priority = 45}; + sched_setscheduler(current, SCHED_FIFO, &PARAM); + printk(KERN_INFO "skey: started update thread\n"); + while (1) { + //reads the keyboard + int row_index = 0; + int column_index = 0; + while (column_index < 10) { + //sets the column pin high for reading + gpio_set_value(column_pins[column_index], 1); + //reads with all the rows + row_index = 0; + while (row_index < 3) { + if (gpio_get_value(row_pins[row_index])) { + printk(KERN_INFO "skey: key pressed at column %d, row %d\n", column_index, row_index); + } + row_index++; } - row_index++; + //sets the row pin low + gpio_set_value(column_pins[column_index], 0); + column_index++; + } + //sleep 2000us= 2ms = 0.002 seconds + usleep_range(2000, 2000); + //for when the thread has to stop + if (kthread_should_stop()) { + break; } - //sets the row pin low - gpio_set_value(column_pins[column_index], 0); - column_index++; } - //updates the timer - mod_timer(&update_timer, jiffies + msecs_to_jiffies(update_period)); + return 0; } /* * This function is called when the module is loaded @@ -86,12 +100,9 @@ static int __init skey_init (void) { } j++; } - //sets up timer for keyboard read function - setup_timer(&update_timer, skey_update, 0); - if (mod_timer(&update_timer, jiffies + msecs_to_jiffies(update_period))) { - printk(KERN_ALERT "skey: failed to set up timer\n"); - return -EINVAL; - } + //sets up update thread + printk("skey: setting up update thread...\n"); + update_task = kthread_run(skey_update_thread, NULL, "skey_update_thread"); printk(KERN_INFO "skey: module finished initiating\n"); return 0; } @@ -112,8 +123,8 @@ static void __exit skey_exit (void) { gpio_free(row_pins[j]); j++; } - //deletes update timer - del_timer(&update_timer); + //deletes the thread + kthread_stop(update_task); printk(KERN_INFO "skey: module exited\n"); return; } |