diff options
| -rw-r--r-- | skey.c | 136 |
1 files changed, 77 insertions, 59 deletions
@@ -6,6 +6,11 @@ #include <linux/delay.h> #include <linux/sched.h> /* + * defines whether to access the gpios so other parts of the kernel module can + * be tested on systems w/o the prerequisite GPIOs + */ +#define USE_GPIO 1 +/* * Unsigned ints containing the BCM pin numbers for the pins used, __initdata * helps with the loading and unloading of data in memory */ @@ -20,7 +25,7 @@ static __initdata char * rlabels[3] = {"R0", "R1", "R2"}; * variables for setting up the thread */ -struct task_struct *update_task; +static struct task_struct *update_task; /* *This function is called every timer-period to actually read the keyboard */ @@ -30,24 +35,29 @@ int skey_update_thread (void *data) { 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); + if (USE_GPIO) { + //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++; } - //sets the row pin low - gpio_set_value(column_pins[column_index], 0); - column_index++; + } else { + printk(KERN_ALERT "skey: currently in test mode with gpio use disabled\n"); } //sleep 2000us= 2ms = 0.002 seconds usleep_range(2000, 2000); @@ -64,41 +74,45 @@ int skey_update_thread (void *data) { */ static int __init skey_init (void) { printk(KERN_INFO "skey: module initiating...\n"); - int i = 0; - //claims the column pins - while (i < 10) { - //checks to see if the gpios are valid - if (!gpio_is_valid(column_pins[i])) { - printk(KERN_ALERT "skey: column_pins[%d], BCM %d request invalid\n", i, column_pins[i]); - return -EINVAL; - } - //requests access of the GPIO - if (gpio_request_one(column_pins[i], GPIOF_OUT_INIT_LOW ,clabels[i])) { - printk(KERN_ALERT "skey: column_pins[%d], BCM %d request failed\n", i, column_pins[i]); - return -EINVAL; - } - if (gpio_direction_output(column_pins[i], 0)) { - printk(KERN_ALERT "skey: column_pins[%d], BCM %d, set output failed\n",i, column_pins[i]); - } - i++; - } - //ditto for row pins - int j = 0; - while (j < 3) { - //checks to see if the gpios are valid - if (!gpio_is_valid(row_pins[j])) { - printk(KERN_ALERT "skey: row_pins[%d], BCM %d request invalid\n", j, row_pins[j]); - return -EINVAL; - } - //requests access of the GPIO - if (gpio_request_one(row_pins[j], GPIOF_DIR_IN ,rlabels[j])) { - printk(KERN_ALERT "skey: row_pins[%d], BCM %d request failed\n", j, row_pins[j]); - return -EINVAL; + if (USE_GPIO) { + int i = 0; + //claims the column pins + while (i < 10) { + //checks to see if the gpios are valid + if (!gpio_is_valid(column_pins[i])) { + printk(KERN_ALERT "skey: column_pins[%d], BCM %d request invalid\n", i, column_pins[i]); + return -EINVAL; + } + //requests access of the GPIO + if (gpio_request_one(column_pins[i], GPIOF_OUT_INIT_LOW ,clabels[i])) { + printk(KERN_ALERT "skey: column_pins[%d], BCM %d request failed\n", i, column_pins[i]); + return -EINVAL; + } + if (gpio_direction_output(column_pins[i], 0)) { + printk(KERN_ALERT "skey: column_pins[%d], BCM %d, set output failed\n",i, column_pins[i]); + } + i++; } - if (gpio_direction_input(row_pins[j])) { - printk(KERN_ALERT "skey: row_pins[%d], BCM %d, set output failed\n",j, row_pins[j]); + //ditto for row pins + int j = 0; + while (j < 3) { + //checks to see if the gpios are valid + if (!gpio_is_valid(row_pins[j])) { + printk(KERN_ALERT "skey: row_pins[%d], BCM %d request invalid\n", j, row_pins[j]); + return -EINVAL; + } + //requests access of the GPIO + if (gpio_request_one(row_pins[j], GPIOF_DIR_IN ,rlabels[j])) { + printk(KERN_ALERT "skey: row_pins[%d], BCM %d request failed\n", j, row_pins[j]); + return -EINVAL; + } + if (gpio_direction_input(row_pins[j])) { + printk(KERN_ALERT "skey: row_pins[%d], BCM %d, set output failed\n",j, row_pins[j]); + } + j++; } - j++; + } else { + printk(KERN_ALERT "skey: currently in test mode with gpio use disabled\n"); } //sets up update thread printk("skey: setting up update thread...\n"); @@ -112,16 +126,20 @@ static int __init skey_init (void) { */ static void __exit skey_exit (void) { printk(KERN_INFO "skey: module exiting...\n"); - //frees column and row pins - int i = 0; - while (i < 10) { - gpio_free(column_pins[i]); - i++; - } - int j = 0; - while (j < 3) { - gpio_free(row_pins[j]); - j++; + if (USE_GPIO) { + //frees column and row pins + int i = 0; + while (i < 10) { + gpio_free(column_pins[i]); + i++; + } + int j = 0; + while (j < 3) { + gpio_free(row_pins[j]); + j++; + } + } else { + printk(KERN_ALERT "skey: currently in test mode with gpio use disabled\n"); } //deletes the thread kthread_stop(update_task); |