1 files changed, 157 insertions, 0 deletions

diff --git a/drivers/i2c/busses/i2c-simtec.c b/drivers/i2c/busses/i2c-simtec.c
new file mode 100644
index 000000000..877017447
--- /dev/null
+++ b/drivers/i2c/busses/i2c-simtec.c
@@ -0,0 +1,157 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2005 Simtec Electronics
+ *	Ben Dooks <ben@simtec.co.uk>
+ *
+ * Simtec Generic I2C Controller
+*/
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+
+#include <linux/i2c.h>
+#include <linux/i2c-algo-bit.h>
+
+struct simtec_i2c_data {
+	struct resource		*ioarea;
+	void __iomem		*reg;
+	struct i2c_adapter	 adap;
+	struct i2c_algo_bit_data bit;
+};
+
+#define CMD_SET_SDA	(1<<2)
+#define CMD_SET_SCL	(1<<3)
+
+#define STATE_SDA	(1<<0)
+#define STATE_SCL	(1<<1)
+
+/* i2c bit-bus functions */
+
+static void simtec_i2c_setsda(void *pw, int state)
+{
+	struct simtec_i2c_data *pd = pw;
+	writeb(CMD_SET_SDA | (state ? STATE_SDA : 0), pd->reg);
+}
+
+static void simtec_i2c_setscl(void *pw, int state)
+{
+	struct simtec_i2c_data *pd = pw;
+	writeb(CMD_SET_SCL | (state ? STATE_SCL : 0), pd->reg);
+}
+
+static int simtec_i2c_getsda(void *pw)
+{
+	struct simtec_i2c_data *pd = pw;
+	return readb(pd->reg) & STATE_SDA ? 1 : 0;
+}
+
+static int simtec_i2c_getscl(void *pw)
+{
+	struct simtec_i2c_data *pd = pw;
+	return readb(pd->reg) & STATE_SCL ? 1 : 0;
+}
+
+/* device registration */
+
+static int simtec_i2c_probe(struct platform_device *dev)
+{
+	struct simtec_i2c_data *pd;
+	struct resource *res;
+	int size;
+	int ret;
+
+	pd = kzalloc(sizeof(struct simtec_i2c_data), GFP_KERNEL);
+	if (pd == NULL)
+		return -ENOMEM;
+
+	platform_set_drvdata(dev, pd);
+
+	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
+	if (res == NULL) {
+		dev_err(&dev->dev, "cannot find IO resource\n");
+		ret = -ENOENT;
+		goto err;
+	}
+
+	size = resource_size(res);
+
+	pd->ioarea = request_mem_region(res->start, size, dev->name);
+	if (pd->ioarea == NULL) {
+		dev_err(&dev->dev, "cannot request IO\n");
+		ret = -ENXIO;
+		goto err;
+	}
+
+	pd->reg = ioremap(res->start, size);
+	if (pd->reg == NULL) {
+		dev_err(&dev->dev, "cannot map IO\n");
+		ret = -ENXIO;
+		goto err_res;
+	}
+
+	/* setup the private data */
+
+	pd->adap.owner = THIS_MODULE;
+	pd->adap.algo_data = &pd->bit;
+	pd->adap.dev.parent = &dev->dev;
+
+	strscpy(pd->adap.name, "Simtec I2C", sizeof(pd->adap.name));
+
+	pd->bit.data = pd;
+	pd->bit.setsda = simtec_i2c_setsda;
+	pd->bit.setscl = simtec_i2c_setscl;
+	pd->bit.getsda = simtec_i2c_getsda;
+	pd->bit.getscl = simtec_i2c_getscl;
+	pd->bit.timeout = HZ;
+	pd->bit.udelay = 20;
+
+	ret = i2c_bit_add_bus(&pd->adap);
+	if (ret)
+		goto err_all;
+
+	return 0;
+
+ err_all:
+	iounmap(pd->reg);
+
+ err_res:
+	release_mem_region(pd->ioarea->start, size);
+
+ err:
+	kfree(pd);
+	return ret;
+}
+
+static int simtec_i2c_remove(struct platform_device *dev)
+{
+	struct simtec_i2c_data *pd = platform_get_drvdata(dev);
+
+	i2c_del_adapter(&pd->adap);
+
+	iounmap(pd->reg);
+	release_mem_region(pd->ioarea->start, resource_size(pd->ioarea));
+	kfree(pd);
+
+	return 0;
+}
+
+/* device driver */
+
+static struct platform_driver simtec_i2c_driver = {
+	.driver		= {
+		.name		= "simtec-i2c",
+	},
+	.probe		= simtec_i2c_probe,
+	.remove		= simtec_i2c_remove,
+};
+
+module_platform_driver(simtec_i2c_driver);
+
+MODULE_DESCRIPTION("Simtec Generic I2C Bus driver");
+MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:simtec-i2c");