Driver for the new range of boards from Simtec Electronics
which use an simple bitwise gpio i2c implementation in an
memory mapped CPLD
Signed-off-by: Ben Dooks <ben-linux at fluff.org>
-------------- next part --------------
--- linux-2.6.14-git10/drivers/i2c/busses/Makefile 2005-10-28 11:28:29.000000000 +0100
+++ linux-2.6.14-simtec2p1/drivers/i2c/busses/Makefile 2005-10-31 16:50:32.000000000 +0000
@@ -34,6 +34,7 @@ obj-$(CONFIG_I2C_RPXLITE) += i2c-rpx.o
obj-$(CONFIG_I2C_S3C2410) += i2c-s3c2410.o
obj-$(CONFIG_I2C_SAVAGE4) += i2c-savage4.o
obj-$(CONFIG_I2C_SIBYTE) += i2c-sibyte.o
+obj-$(CONFIG_I2C_SIMTEC) += i2c-simtec.o
obj-$(CONFIG_I2C_SIS5595) += i2c-sis5595.o
obj-$(CONFIG_I2C_SIS630) += i2c-sis630.o
obj-$(CONFIG_I2C_SIS96X) += i2c-sis96x.o
--- linux-2.6.14-git10/drivers/i2c/busses/Kconfig 2005-11-07 15:07:25.000000000 +0000
+++ linux-2.6.14-simtec2p1/drivers/i2c/busses/Kconfig 2005-11-07 15:01:53.000000000 +0000
@@ -369,6 +369,19 @@ config I2C_SIBYTE
help
Supports the SiByte SOC on-chip I2C interfaces (2 channels).
+config I2C_SIMTEC
+ tristate "Simtec Generic I2C interface"
+ depends on I2C
+ select I2C_ALGOBIT
+ help
+ If you say yes to this option, support will be inclyded for
+ the Simtec Generic I2C interface. This driver is for the
+ simple I2C bus used on newer Simtec products for general
+ I2C, such as DDC on the Simtec BBD2016A.
+
+ This driver can also be build as a module. If so, the module
+ will be called i2c-simtec.
+
config SCx200_I2C
tristate "NatSemi SCx200 I2C using GPIO pins"
depends on SCx200_GPIO && I2C
--- linux-2.6.14-git10/drivers/i2c/busses/i2c-simtec.c 1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.14-simtec2p1/drivers/i2c/busses/i2c-simtec.c 2005-11-08 10:36:28.000000000 +0000
@@ -0,0 +1,201 @@
+/* linux/drivers/i2c/busses/i2c-simtec.c
+ *
+ * Copyright (C) 2005 Simtec Electronics
+ * Ben Dooks <ben at simtec.co.uk>
+ *
+ * Simtec Generic I2C Controller
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+*/
+
+#include <linux/config.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/platform_device.h>
+
+#include <linux/i2c.h>
+#include <linux/i2c-algo-bit.h>
+
+#include <asm/io.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 device *dev)
+{
+ struct platform_device *pdev = to_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) {
+ dev_err(dev, "cannot allocate private data\n");
+ return -ENOMEM;
+ }
+
+ dev_set_drvdata(dev, pd);
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (res == NULL) {
+ dev_err(dev, "cannot find IO resource\n");
+ ret = -ENOENT;
+ goto exit_err;
+ }
+
+ size = (res->end-res->start)+1;
+
+ pd->ioarea = request_mem_region(res->start, size, pdev->name);
+
+ if (pd->ioarea == NULL) {
+ dev_err(dev, "cannot request IO\n");
+ ret = -ENXIO;
+ goto exit_err;
+ }
+
+ pd->reg = ioremap(res->start, size);
+
+ if (pd->reg == NULL) {
+ dev_err(dev, "cannot map IO\n");
+ ret = -ENXIO;
+ goto exit_err_res;
+ }
+
+ /* setup the private data */
+
+ pd->adap.owner = THIS_MODULE;
+ pd->adap.algo_data = &pd->bit;
+ pd->adap.dev.parent = dev;
+
+ strlcpy(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 exit_err_all;
+
+ return 0;
+
+ exit_err_all:
+ iounmap(pd->reg);
+
+ exit_err_res:
+ release_resource(pd->ioarea);
+ kfree(pd->ioarea);
+
+ exit_err:
+ kfree(pd);
+ return ret;
+}
+
+static int simtec_i2c_remove(struct device *dev)
+{
+ struct simtec_i2c_data *pd = dev_get_drvdata(dev);
+
+ if (pd) {
+ i2c_bit_del_bus(&pd->adap);
+
+ if (pd->reg) {
+ iounmap(pd->reg);
+ pd->reg = NULL;
+ }
+
+ if (pd->ioarea) {
+ release_resource(pd->ioarea);
+ kfree(pd->ioarea);
+ pd->ioarea = NULL;
+ }
+
+ kfree(pd);
+ }
+
+ return 0;
+}
+
+
+/* device driver */
+
+static struct device_driver simtec_i2c_driver = {
+ .name = "simtec-i2c",
+ .owner = THIS_MODULE,
+ .bus = &platform_bus_type,
+ .probe = simtec_i2c_probe,
+ .remove = simtec_i2c_remove,
+};
+
+static int __init i2c_adap_simtec_init(void)
+{
+ return driver_register(&simtec_i2c_driver);
+}
+
+static void __exit i2c_adap_simtec_exit(void)
+{
+ driver_unregister(&simtec_i2c_driver);
+}
+
+module_init(i2c_adap_simtec_init);
+module_exit(i2c_adap_simtec_exit);
+
+MODULE_DESCRIPTION("Simtec Generic I2C Bus driver");
+MODULE_AUTHOR("Ben Dooks, <ben at simtec.co.uk>");
+MODULE_LICENSE("GPL");
