From: Peter Henn <Peter.Henn@web.de>
Date: Mon, 23 Apr 2018 22:58:44 +0000 (+0000)
Subject: First support PL2303-HXD GPIO 2 & 3
X-Git-Url: http://git.linex4red.de/pub/pl2303-ft232-gpio.git/commitdiff_plain?ds=inline

First support PL2303-HXD GPIO 2 & 3

- extend pl2303 to support GPIO 2 & 3
- adjust TODO file
---

diff --git a/TODO b/TODO
index cf3e410..b1a8717 100644
--- a/TODO
+++ b/TODO
@@ -1,6 +1,5 @@
 TODO:
-- add support for GPIO2 and GPIO3 of PL2303, see also
-  https://patchwork.kernel.org/patch/4815351/
+- add GPIO number range check, depending on device
 - add debug code for testing FT232R, especially reading GPIO configuration
 - test mixed input and output with FT232R and PL2303
 - ...
diff --git a/pl2303.c b/pl2303.c
index fb17c19..d1ddcc6 100644
--- a/pl2303.c
+++ b/pl2303.c
@@ -27,6 +27,12 @@
 #define VENDOR_WRITE_REQUEST_TYPE	0x40
 #define VENDOR_WRITE_REQUEST		0x01
 
+#define GPIO_01_RD_CTRL		0x0081
+#define GPIO_01_WR_CTRL		0x0001
+#define GPIO_23_DIR_RD_CTRL	0x8c8c
+#define GPIO_23_DIR_WR_CTRL	0x0c0c
+#define GPIO_23_VAL_RD_CTRL	0x8d8d
+#define GPIO_23_VAL_WR_CTRL	0x0d0d
 
 int get_device_vid()
 {
@@ -39,83 +45,109 @@ int get_device_pid()
 }
 
 /* Get current GPIO register from PL2303 */
-char gpio_read_reg(libusb_device_handle *h)
+char gpio_read_reg(libusb_device_handle *h, unsigned short ctrl)
 {
 	char buf;
 	int bytes = libusb_control_transfer(
 		h,             // handle obtained with usb_open()
 		VENDOR_READ_REQUEST_TYPE, // bRequestType
 		VENDOR_READ_REQUEST,      // bRequest
-		0x0081,              // wValue
-		0,              // wIndex
-		&buf,             // pointer to destination buffer
-		1,  // wLength
+		ctrl,          // wValue
+		0,             // wIndex
+		&buf,          // pointer to destination buffer
+		1,             // wLength
 		1000
 		);
 	handle_error(bytes);
 	return buf;
 }
 
-void gpio_write_reg(libusb_device_handle *h, unsigned char reg)
+void gpio_write_reg(libusb_device_handle *h, unsigned short ctrl, unsigned char reg)
 {
 	int bytes = libusb_control_transfer(
 		h,             // handle obtained with usb_open()
 		VENDOR_WRITE_REQUEST_TYPE, // bRequestType
 		VENDOR_WRITE_REQUEST,      // bRequest
-		1,              // wValue
-		reg,              // wIndex
+		ctrl,          // wValue
+		reg,           // wIndex
 		0,             // pointer to destination buffer
-		0,  // wLength
+		0,             // wLength
 		1000
 		);
 	handle_error(bytes);
-	
 }
 
-int gpio_dir_shift(int gpio) {
-	if (gpio == 0) 
-		return 4;
-	if (gpio == 1) 
-		return 5;
-	return 4; /* default to 0 */
+int gpio_dir_mask(int gpio) {
+	switch (gpio) {
+		case 0: return 0x10;
+		case 1: return 0x20;
+		case 2: return 0x03;
+		case 3: return 0x0c;
+	}
+	return 0x10; /* default to gpio 0 */
 }
 
 int gpio_val_shift(int gpio) {
-	if (gpio == 0) 
-		return 6;
-	if (gpio == 1) 
-		return 7;
-	return 6; /* default to 0 */
+	switch (gpio) {
+		case 0: return 6;
+		case 1: return 7;
+		case 2: return 0;
+		case 3: return 1;
+	}
+	return 6; /* default to gpio 0 */
 }
 
 
 void gpio_out(libusb_device_handle *h, int gpio, int value)
 {
-	int shift_dir = gpio_dir_shift(gpio);
  	int shift_val = gpio_val_shift(gpio);
-	unsigned char reg = gpio_read_reg(h);
-	reg |= (1 << shift_dir);
-	reg &= ~(1 << shift_val);
-	reg |= (value << shift_val);
-	gpio_write_reg(h, reg);
+	unsigned char reg;
+
+	if (2 > gpio) {
+		reg = gpio_read_reg(h, GPIO_01_RD_CTRL);
+		reg |= gpio_dir_mask(gpio);  /* set output direction */
+		reg &= ~(1 << shift_val);    /* reset gpio */
+		reg |= (value << shift_val); /* set gpio to value */
+		gpio_write_reg(h, GPIO_01_WR_CTRL, reg);
+	} else {
+		reg = gpio_read_reg(h, GPIO_23_VAL_RD_CTRL);
+		reg &= ~(1 << shift_val);    /* reset gpio */
+		reg |= (value << shift_val); /* set gpio to value */
+		gpio_write_reg(h, GPIO_23_VAL_WR_CTRL, reg);
+
+		reg = gpio_read_reg(h, GPIO_23_DIR_RD_CTRL);
+		reg |= gpio_dir_mask(gpio);  /* set output direction */
+		gpio_write_reg(h, GPIO_23_DIR_WR_CTRL, reg);
+	}
 }
 
 void gpio_in(libusb_device_handle *h, int gpio, int pullup)
 {
-	int shift_dir = gpio_dir_shift(gpio);
  	int shift_val = gpio_val_shift(gpio);
-
-	unsigned char reg = gpio_read_reg(h);
-	reg &= ~(1 << shift_dir);
-	reg &= ~(1 << shift_val);
-	reg |= (pullup << shift_val);
-	gpio_write_reg(h, reg);
+	unsigned char reg;
+
+	if (2 > gpio) {
+		reg = gpio_read_reg(h, GPIO_01_RD_CTRL);
+		reg &= ~(gpio_dir_mask(gpio));	/* set input direction */
+		reg &= ~(1 << shift_val);	/* reset gpio value */
+		reg |= (pullup << shift_val);	/* pullup gpio value */
+		gpio_write_reg(h, GPIO_01_WR_CTRL, reg);
+	} else {
+		reg = gpio_read_reg(h, GPIO_23_DIR_RD_CTRL);
+		reg &= ~(gpio_dir_mask(gpio));	/* set input direction */
+		gpio_write_reg(h, GPIO_23_DIR_WR_CTRL, reg);
+
+		reg = gpio_read_reg(h, GPIO_23_VAL_RD_CTRL);
+		reg &= ~(1 << shift_val);	/* reset gpio value */
+		reg |= (pullup << shift_val);	/* pullup gpio value */
+		gpio_write_reg(h, GPIO_23_VAL_WR_CTRL, reg);
+	}
 }
 
 int gpio_read(libusb_device_handle *h, int gpio)
 {
-	unsigned char r = gpio_read_reg(h);
+	unsigned char r = gpio_read_reg(h, (2 > gpio) ? GPIO_01_RD_CTRL : GPIO_23_VAL_RD_CTRL);
 	int shift = gpio_val_shift(gpio);
-	return (r & (1<<shift));
+	return (r & (1 << shift));
 }