1 files changed, 127 insertions, 0 deletions
diff --git a/snd-alpx-dkms/snd-alpx/alpx_gpio.c b/snd-alpx-dkms/snd-alpx/alpx_gpio.c
new file mode 100644
index 0000000..4734057
--- /dev/null
+++ b/snd-alpx-dkms/snd-alpx/alpx_gpio.c
@@ -0,0 +1,127 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+*  Support for Digigram AlpX PCI-e boards
+*
+*  Copyright (c) 2024 Digigram Digital (info@digigram.com)
+*/
+
+
+#include "alpx_gpio.h"
+
+#include <linux/io.h>
+
+static inline bool alpx_gpio_is_an_input (struct alpx_device *alpx_dev, unsigned offset)
+{
+	return offset < alpx_dev->variant->gpios.inputs_qty;
+}
+
+
+int alpx_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+	struct alpx_device *alpx_dev = gpiochip_get_data(chip);
+	u32 value;
+	
+	if (alpx_gpio_is_an_input(alpx_dev, offset)) {
+		value = readl(alpx_dev->base + alpx_dev->variant->gpios.base + alpx_dev->variant->gpios.inputs_reg_offset);
+		
+		dev_dbg( alpx_dev->dev,"[0x%08x] =>[0x%08x]\n", alpx_dev->variant->gpios.base + alpx_dev->variant->gpios.inputs_reg_offset,  value);
+	}
+	else {
+		value = readl(alpx_dev->base + alpx_dev->variant->gpios.base + alpx_dev->variant->gpios.outputs_reg_offset);
+		
+		dev_dbg( alpx_dev->dev,"[0x%08x] =>[0x%08x]\n", alpx_dev->variant->gpios.base + alpx_dev->variant->gpios.outputs_reg_offset,  value);
+		//translate offset -> bit rank
+		offset -= alpx_dev->variant->gpios.inputs_qty;
+	}
+	
+	return ALPX_GPIO_VALUE(offset, value);
+}
+
+void alpx_gpio_set(struct gpio_chip *chip, unsigned offset,
+			int gpio_value)
+{
+	struct alpx_device *alpx_dev = gpiochip_get_data(chip);
+	unsigned int value;
+	
+		
+	if (alpx_gpio_is_an_input(alpx_dev, offset))
+		return;
+
+	//translate Offset to bit rank
+	offset -= alpx_dev->variant->gpios.inputs_qty;
+
+	value = readl(alpx_dev->base + alpx_dev->variant->gpios.base + alpx_dev->variant->gpios.outputs_reg_offset );
+	
+	dev_dbg( alpx_dev->dev,"read [0x%08x] =>0x%08x\n",alpx_dev->variant->gpios.base + alpx_dev->variant->gpios.outputs_reg_offset,  value);
+
+
+	value &= ~ALPX_GPIO_MASK(offset);
+	value |= ALPX_GPIO_SEL(offset, gpio_value);
+	
+	dev_dbg( alpx_dev->dev,"write 0x%08x =>[0x%08x]\n", value , alpx_dev->variant->gpios.base + alpx_dev->variant->gpios.outputs_reg_offset);
+	
+	writel(value, alpx_dev->base + alpx_dev->variant->gpios.base + alpx_dev->variant->gpios.outputs_reg_offset);
+}
+
+int alpx_gpio_get_direction(struct gpio_chip *chip, unsigned offset)
+{
+	struct alpx_device *alpx_dev = gpiochip_get_data(chip);
+	
+	if (offset >= chip->ngpio)
+		return -EINVAL;
+	
+	dev_dbg( alpx_dev->dev,"Offset %d is %s\n", 
+			 offset, alpx_gpio_is_an_input(alpx_dev, offset) ? "INPUT" : "OUTPUT");
+	
+	return alpx_gpio_is_an_input(alpx_dev, offset) ? GPIOF_DIR_IN : GPIOF_DIR_OUT;
+}
+
+int alpx_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
+					int gpio_value)
+{
+	struct alpx_device *alpx_dev = gpiochip_get_data(chip);
+	if (alpx_gpio_is_an_input(alpx_dev, offset))
+		return -EINVAL;
+
+	alpx_gpio_set(chip, offset, gpio_value);
+
+	return 0;
+}
+
+int alpx_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
+{
+	/* All ports handle INPUTs operations */
+	return 0;
+}
+
+int alpx_gpio_register(struct alpx_device *alpx_dev, const char* card_name)
+{
+	struct gpio_chip *chip = &alpx_dev->gpio_chip;
+
+	chip->parent = alpx_dev->dev;
+	chip->owner = THIS_MODULE;
+	chip->label = card_name;
+	chip->base = -1;
+
+	chip->ngpio = alpx_dev->variant->gpios.inputs_qty + alpx_dev->variant->gpios.outputs_qty;
+	chip->get = alpx_gpio_get;
+	chip->set = alpx_gpio_set;
+	chip->get_direction = alpx_gpio_get_direction;
+	chip->direction_output = alpx_gpio_direction_output;
+	chip->direction_input = alpx_gpio_direction_input;
+	
+	dev_dbg( alpx_dev->dev,"%s(): creating GP(%d)I(%d)O for %s.\n", __func__, 
+			alpx_dev->variant->gpios.inputs_qty,
+			alpx_dev->variant->gpios.outputs_qty,
+			chip->label);
+
+	return gpiochip_add_data(chip, alpx_dev);
+}
+
+void alpx_gpio_unregister(struct alpx_device *alpx_dev)
+{
+	struct gpio_chip* const chip = &alpx_dev->gpio_chip;	
+	if (chip->parent == alpx_dev->dev)
+		gpiochip_remove(chip);
+}
+