Add driver for CDS9K GPIO IP block

1 files changed, 69 insertions, 0 deletions

diff --git a/cds9k-gpio.c b/cds9k-gpio.c
new file mode 100644
index 0000000..80b56ac
--- /dev/null
+++ b/cds9k-gpio.c
@@ -0,0 +1,69 @@
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/regmap.h>
+#include <linux/gpio/regmap.h>
+
+#define GPIO_REG_PORT 0x0
+#define GPIO_REG_DIR  0x1
+
+static int cds9k_gpio_probe(struct platform_device *pdev)
+{
+	printk("Hello from the GPIO driver. Pdev name is %s\n", pdev->name);
+	struct gpio_regmap_config config = {};
+	struct regmap *regmap;
+	u32 base;
+	int ret;
+	const char *parent_name = dev_name(pdev->dev.parent);
+
+	if (!pdev->dev.parent) {
+		printk("NULL parent to platform device\n");
+		return -ENODEV;
+	}
+
+	ret = device_property_read_u32(&pdev->dev, "reg", &base);
+	if (ret) {
+		printk("Failed to get u32 reg property on platform device\n");
+		return -EINVAL;
+	}
+
+	regmap = dev_get_regmap(pdev->dev.parent, NULL);
+	if (!regmap) {
+		printk("dev_get_regmap failed\n");
+		return -ENODEV;
+	}
+
+	config.parent = &pdev->dev;
+	config.regmap = regmap;
+	/* XXX would be nice to use these if specified in DT
+	config.names =
+	config.label =
+	*/
+	config.ngpio = 8;
+	config.reg_dat_base = base + GPIO_REG_PORT;
+	config.reg_set_base = base + GPIO_REG_PORT;
+	config.reg_dir_out_base = base + GPIO_REG_DIR;
+
+	printk("About to return from probe\n");
+	return PTR_ERR_OR_ZERO(devm_gpio_regmap_register(&pdev->dev, &config));
+	//0;
+}
+
+static struct of_device_id cds9k_gpio_of_match[] = {
+	{ .compatible = "david,cds9k-gpio" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, cds9k_gpio_of_match);
+
+static struct platform_driver cds9k_gpio = {
+	.driver = {
+		.name = "cds9k-gpio",
+		.of_match_table = cds9k_gpio_of_match,
+	},
+	.probe = cds9k_gpio_probe
+};
+module_platform_driver(cds9k_gpio);
+
+MODULE_AUTHOR("David Phillips <david@yeah.nah.nz>");
+MODULE_DESCRIPTION("GPIO driver for the CDS9K board controller");
+MODULE_LICENSE("GPL v2");