ioc: Add reset GPIO

ioc/kernel-driver/device-tree-opi-pc.patch

@@ -1,18 +1,41 @@
 diff --git a/arch/arm/boot/dts/sun8i-h3-orangepi-pc.dts b/arch/arm/boot/dts/sun8i-h3-orangepi-pc.dts
-index 5aff8ecc66cb..c8201e79dff3 100644
+index c8201e79dff3..5407742acad6 100644
 --- a/arch/arm/boot/dts/sun8i-h3-orangepi-pc.dts
 +++ b/arch/arm/boot/dts/sun8i-h3-orangepi-pc.dts
-@@ -211,9 +211,12 @@
+@@ -210,12 +210,22 @@ &uart0 {
+ 	status = "okay";
  };
  
++&pio {
++	lw35ioc_pins: lw35ioc-pins {
++		pins = "PA10";
++		function = "gpio_out";
++	};
++};
++
  &uart1 {
-+	status = "okay";
+ 	status = "okay";
  	pinctrl-names = "default";
  	pinctrl-0 = <&uart1_pins>;
--	status = "disabled";
+ 	lw35ioc@0 {
-+	lw35ioc@0 {
+ 		compatible = "brother,lw35";
-+		compatible = "brother,lw35";
++		pinctrl-names = "default";
-+	};
++		pinctrl-0 = <&lw35ioc_pins>;
++		rst-gpios = <&pio 0 10 GPIO_ACTIVE_LOW>;
+ 	};
  };
  
- &uart2 {
+@@ -242,3 +252,13 @@ &usbphy {
+ 	/* VBUS on USB host ports are always on */
+ 	status = "okay";
+ };
++
++&spi0 {
++	status = "okay";
++	lmg6202ulyt@0 {
++		compatible = "hitachi,lmg6202ulyt";
++		reg = <0x0>;
++		spi-max-frequency = <2000000>;
++		cs-gpios = <0>, <&pio 0 3 GPIO_ACTIVE_LOW>;
++	};
++};

ioc/kernel-driver/lw35ioc.c

@@ -7,6 +7,7 @@
 #include <linux/serdev.h>
 #include <linux/types.h>
 #include <linux/input.h>
+#include <linux/gpio/consumer.h>
 
 // #define ENABLE_DEBUG ENABLE_DEBUG
 
@@ -43,20 +44,25 @@ static int keycode_map[] = {
 	KEY_SYSRQ
 };
 
-enum lw35ioc_state {SYNC, TYPE, KEYBOARD, PRINTER};
+enum lw35ioc_state {PASSIVE, PASSTHROUGH, ACTIVE};
+
+enum lw35ioc_packet_state {SYNC, TYPE, KEYBOARD, PRINTER};
 
 struct lw35ioc_packet {
-	enum lw35ioc_state state;
+	enum lw35ioc_packet_state state;
 };
 
 struct lw35ioc_priv {
 	struct serdev_device *serdev;
 	struct input_dev *input_dev;
+	struct gpio_desc *gpio_rst; /* GPIO to reset both AVRs */
 	
+	enum lw35ioc_state state;
 	struct lw35ioc_packet packet;
 };
 
-static int lw35ioc_receive_buf(struct serdev_device *serdev,
+
+static int lw35ioc_process_buf(struct serdev_device *serdev,
 			       const unsigned char *data,
 			       size_t count)
 {
@@ -107,6 +113,17 @@ static int lw35ioc_receive_buf(struct serdev_device *serdev,
 	return i;
 }
 
+static int lw35ioc_receive_buf(struct serdev_device *serdev,
+			       const unsigned char *data,
+			       size_t count)
+{
+	struct lw35ioc_priv *priv = serdev_device_get_drvdata(serdev);
+	if (priv->state == ACTIVE)
+		return lw35ioc_process_buf(serdev, data, count);
+
+	return count; /* Pretend we read all data */
+}
+
 static void lw35ioc_write_wakeup(struct serdev_device *serdev)
 {
 	dev_info(&serdev->dev, "Write wakeup\n");
@@ -118,6 +135,14 @@ static struct serdev_device_ops lw35ioc_serdev_ops = {
 	.write_wakeup = lw35ioc_write_wakeup,
 };
 
+static void lw35ioc_set_hw_reset(struct serdev_device *serdev,
+				 int reset_active)
+{
+	struct lw35ioc_priv *priv = serdev_device_get_drvdata(serdev);
+
+	gpiod_set_value(priv->gpio_rst, !reset_active);
+}
+
 static int lw35ioc_probe(struct serdev_device *serdev)
 {
 	struct lw35ioc_priv *priv = NULL;
@@ -128,6 +153,7 @@ static int lw35ioc_probe(struct serdev_device *serdev)
 
 	printk(KERN_INFO "lw35ioc: probe\n");
 
+	/* Allocate memory */
 	priv = devm_kzalloc(&serdev->dev,
 			    sizeof(struct lw35ioc_priv),
 			    GFP_KERNEL);
@@ -135,11 +161,13 @@ static int lw35ioc_probe(struct serdev_device *serdev)
 		printk(KERN_ERR "lw35ioc: Not enough memory.\n");
 		return -ENOMEM;
 	}
+	priv->state = PASSIVE;
 	priv->serdev = serdev;
 	priv->packet.state = SYNC;
 	serdev_device_set_drvdata(serdev, priv);
 	serdev_device_set_client_ops(serdev, &lw35ioc_serdev_ops);
 
+	/* Register input device */
 	input_dev = devm_input_allocate_device(&serdev->dev);
 	if (!input_dev) {
 		dev_err(&serdev->dev, "Unable to allocate input device.\n");
@@ -156,25 +184,37 @@ static int lw35ioc_probe(struct serdev_device *serdev)
 	ret = input_register_device(input_dev);
 	if (ret) {
 		dev_err(&serdev->dev, "Unable to register input device.\n");
-		goto fail0;
+		goto fail_input;
 	}
 
 	ret = serdev_device_open(serdev);
 	if (ret) {
 		dev_err(&serdev->dev, "Unable to open device.\n");
-		goto fail1;
+		goto fail_serdev;
 	}
 
 	speed = serdev_device_set_baudrate(serdev, speed);
 	dev_info(&serdev->dev, "Using baudrate: %u\n", speed);
 
+	/* Register GPIO */
+	priv->gpio_rst = gpiod_get_index(&serdev->dev,
+					 "rst",
+					 0,
+					 GPIOD_OUT_LOW);
+	lw35ioc_set_hw_reset(serdev, 0);
+
+	if (IS_ERR(priv->gpio_rst)) {
+		dev_err(&serdev->dev, "Unable to get reset GPIO.\n");
+		ret = -ENODEV;
+		goto fail_gpio;
+	}
 	dev_info(&serdev->dev, "Loaded driver.\n");
 
 	return 0;
-
+fail_gpio:
-fail1:
+fail_serdev:
 	input_unregister_device(input_dev);
-fail0:
+fail_input:
 	devm_kfree(&serdev->dev, input_dev);
 	return ret;
 }
@@ -183,6 +223,8 @@ static void lw35ioc_remove(struct serdev_device *serdev)
 {
 	struct lw35ioc_priv *priv = serdev_device_get_drvdata(serdev);
 
+	lw35ioc_set_hw_reset(serdev, 1);
+	gpiod_put(priv->gpio_rst);
 	serdev_device_close(priv->serdev);
 	input_unregister_device(priv->input_dev);