Add basic device interaction to get revision and firmware version.

linux_driver/ai2c_interface.h

+../arduino_sketch/ai2c_interface.h
\ No newline at end of file

linux_driver/arduino_i2c.c

@@ -39,6 +39,7 @@
  */
 #include "ai2c.h"
 #include "ai2c_platform_data.h"
+#include "ai2c_interface.h"
 
 #define IRQ_GPIO_PIN	9
 #define GPIO_IRQ_NAME	"ai2c_keyboard_irq"
@@ -51,6 +52,42 @@ static LIST_HEAD(driver_list);
 static DEFINE_MUTEX(driver_list_lock);
 
 static void
+device_write_register(struct i2c_client *client, uint8_t raddr, uint8_t value) {
+	uint8_t tmp[2];
+
+	tmp[0] = raddr;
+	tmp[1] = value;
+	i2c_master_send(client, tmp, 2);
+}
+
+#if 0
+static uint8_t
+device_read_byte(struct i2c_client *client) {
+	uint8_t tmp;
+
+	i2c_master_recv(client, &tmp, 1);
+
+	return tmp;
+}
+
+static uint16_t
+device_read_word(struct i2c_client *client) {
+	uint16_t tmp;
+
+	i2c_master_recv(client, (unsigned char *)&tmp, 1);
+
+	return tmp;
+}
+#endif
+
+static void
+device_read_register(struct i2c_client *client, void *buffer, uint8_t raddr, uint8_t len) {
+	device_write_register(client, AI2C_REGISTER_READ_ADDR, raddr);
+	device_write_register(client, AI2C_REGISTER_READ_BYTES, len);
+	i2c_master_recv(client, (unsigned char *)buffer, len);
+}
+
+static void
 ai2c_intr(struct work_struct *work) {
 	arduino_i2c_driver_data_t *drv_info = container_of(
 			work, arduino_i2c_driver_data_t, intr_upper_work);
@@ -81,8 +118,12 @@ ai2c_intr_lower(int irq, void *data) {
 
 static int
 ai2c_probe(struct i2c_client *client, const struct i2c_device_id *id) {
+	int i;
 	int ret = 0;
 	int flags = 0;
+	uint16_t dev_id;
+	uint8_t dev_rev;
+	char dev_build_str[AI2C_VER_STR_LEN];
 	const arduino_i2c_keyboard_platform_data_t *pdata =
 		dev_get_platdata(&client->dev);
 	arduino_i2c_driver_data_t *drv_info = NULL;
@@ -94,6 +135,19 @@ ai2c_probe(struct i2c_client *client, const struct i2c_device_id *id) {
 		goto out;
 	}
 
+	/*
+	 * Get/validate/print device information
+	 */
+	device_read_register(client, &dev_id, AI2C_REGISTER_ID_LOW, 2);
+	device_read_register(client, &dev_rev, AI2C_REGISTER_REG_REV, 1);
+	for (i = 0; i < AI2C_VER_STR_LEN; i++) {
+		device_read_register(client, &(dev_build_str[i]), AI2C_REGISTER_VERS_STR + i, 1);
+	}
+	dev_build_str[sizeof(dev_build_str) - 1] = '\0';
+
+	dev_info(&client->dev, "Device ID: 0x%04x\nDevice Revision: 0x%02x\nDevice Firmware Build: \"%s\"\n",
+			dev_id, dev_rev, dev_build_str);
+
 	drv_info = (arduino_i2c_driver_data_t *)kmalloc(sizeof(arduino_i2c_driver_data_t), GFP_KERNEL);
 	if (!drv_info) {
 		dev_err(&client->dev, "Unable to allocate driver memory");