here is the updated version of the floppy controller to I2C
adapter driver, which uses the Motor Control and Disk Changed
lines to interface to an I2C bus.
I hope I fixed the style issues (except for the access to
global var from "remove" function - to keep it similar to
the i2c-parport-light for now)
of course the patch is compile and run tested on PC style
hardware with my test circuit connecting to an LM75 and
LM85 (temp/fan/pwm)
please consider for (mainline) inclusion!
TIA,
Herbert
Signed-off-by: Herbert Poetzl <[EMAIL PROTECTED]>
diff -NurpP --minimal linux-2.6.27-rc3/Documentation/i2c/busses/i2c-floppy
linux-2.6.27-rc3-fi2c-v0.2/Documentation/i2c/busses/i2c-floppy
--- linux-2.6.27-rc3/Documentation/i2c/busses/i2c-floppy 1970-01-01
01:00:00.000000000 +0100
+++ linux-2.6.27-rc3-fi2c-v0.2/Documentation/i2c/busses/i2c-floppy
2008-08-18 04:34:53.000000000 +0200
@@ -0,0 +1,38 @@
+Kernel driver i2c-floppy
+
+Author: Herbert Poetzl <[EMAIL PROTECTED]>
+
+This driver is for a simple do-it-yourself floppy controller to
+I2C adapters which uses direct I/O access to control both Motor
+Enable lines (A/B) and read back data via the Disk Changed line.
+
+The following circuit is not suited to be used together with
+a Floppy drive (which would need some logic to work properly)
+but as replacement.
+
+ +---+
+ | F | Motor Enable A [/MOTEA,10] -------------- SCL
+ | L |
+ | O | Motor Enable B [/MOTEB,16] ------+------- SDA
+ | P | |
+ | P | |
+ | Y | Disk Change [/DSKCHG,34] ------+ +-- GND
+ +-+-+ |
+ | |
+ GND GND
+
+the Motor Enable output of Floppy Disk Controllers is an open
+drain output (48mA), usually pulled up to +5V via 1k or higher,
+and the Disk Change is a Schmitt Trigger (0.8V/2.2V) input with
+max 150uA input current (data taken from the WD/FDC 37C6xx
+Floppy Disk Subsystem Controller datasheets, which basically
+combine all the necessary parts of the PC Floppy Circuit)
+
+so it should be fine to connect it to all 5V i2c devices, and
+most 3.3V devices (which are usually capable of handling 5V
+i2c bus voltages)
+
+power for those devices can be drawn from either the Floppy
+power connector (+5V/+12V) or from the SATA 3.3V lines
+(or if you prefer from some external source)
+
diff -NurpP --minimal linux-2.6.27-rc3/drivers/i2c/busses/i2c-floppy.c
linux-2.6.27-rc3-fi2c-v0.2/drivers/i2c/busses/i2c-floppy.c
--- linux-2.6.27-rc3/drivers/i2c/busses/i2c-floppy.c 1970-01-01
01:00:00.000000000 +0100
+++ linux-2.6.27-rc3-fi2c-v0.2/drivers/i2c/busses/i2c-floppy.c 2008-08-18
03:35:34.000000000 +0200
@@ -0,0 +1,261 @@
+/* ------------------------------------------------------------------------ *
+ * i2c-floppy.c I2C bus over floppy controller *
+ * ------------------------------------------------------------------------ *
+ Copyright (C) 2008 Herbert Poetzl <[EMAIL PROTECTED]>
+
+ Somewhat based on i2c-parport-light.c driver
+ Copyright (C) 2003-2007 Jean Delvare <[EMAIL PROTECTED]>
+
+ 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ * ------------------------------------------------------------------------ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/ioport.h>
+#include <linux/i2c.h>
+#include <linux/i2c-algo-bit.h>
+#include <linux/io.h>
+
+static struct platform_device *pdev;
+static unsigned char dor;
+
+static u16 base;
+module_param(base, ushort, 0);
+MODULE_PARM_DESC(base, "Base I/O address");
+
+
+#define DEFAULT_BASE 0x3F0 /* for PC style hardware */
+#define DRVNAME "i2c-floppy"
+
+
+#define FOFF_DOR 0x02
+#define FOFF_DIR 0x07
+
+#define FDOR_MOTEA 0x10
+#define FDOR_MOTEB 0x20
+
+#define FDIR_DCHNG 0x80
+
+#define SCL FDOR_MOTEA
+#define SDA FDOR_MOTEB
+#define SDA_IN FDIR_DCHNG
+
+#define LO_INV (SDA|SCL)
+#define LI_INV (SDA_IN)
+
+
+/* ----- Device list ------------------------------------------------------ */
+
+#if 0
+struct i2c_floppy_data {
+ unsigned char dor;
+};
+
+struct i2c_floppy {
+ struct i2c_adapter adapter;
+ struct i2c_algo_bit_data algo_data;
+ struct i2c_floppy_data data;
+ struct i2c_floppy *next;
+};
+#endif
+
+
+/* ----- Low-level floppy access ------------------------------------------ */
+
+static inline void port_dor_out(unsigned char d)
+{
+ outb(d ^ LO_INV, base + FOFF_DOR);
+}
+
+static inline unsigned char port_dir_in(void)
+{
+ return inb(base + FOFF_DIR) ^ LI_INV;
+}
+
+
+/* ----- I2C algorithm call-back functions and structures ----------------- */
+
+static void floppy_setscl(void *data, int state)
+{
+ if (state)
+ dor |= SCL;
+ else
+ dor &= ~SCL;
+
+ port_dor_out(dor);
+}
+
+static void floppy_setsda(void *data, int state)
+{
+ if (state)
+ dor |= SDA;
+ else
+ dor &= ~SDA;
+
+ port_dor_out(dor);
+}
+
+static int floppy_getsda(void *data)
+{
+ return port_dir_in() & SDA_IN;
+}
+
+/* Encapsulate the functions above in the correct structure
+ Note that getscl is set to NULL because SCL cannot be read
+ back with the current driver */
+static struct i2c_algo_bit_data floppy_algo_data = {
+ .setsda = floppy_setsda,
+ .setscl = floppy_setscl,
+ .getsda = floppy_getsda,
+ .udelay = 50,
+ .timeout = HZ,
+};
+
+
+/* ----- Driver registration ---------------------------------------------- */
+
+static struct i2c_adapter floppy_adapter = {
+ .owner = THIS_MODULE,
+ .class = I2C_CLASS_HWMON,
+ .algo_data = &floppy_algo_data,
+ .name = "Floppy controller adapter",
+};
+
+static int __devinit i2c_floppy_probe(struct platform_device *pdev)
+{
+ int err;
+ struct resource *res;
+
+ res = platform_get_resource(pdev, IORESOURCE_IO, 0);
+ if (!request_region(res->start, res->end - res->start + 1, DRVNAME))
+ return -EBUSY;
+
+ /* Reset hardware to a sane state (SCL and SDA high) */
+ floppy_setsda(NULL, 1);
+ floppy_setscl(NULL, 1);
+
+ floppy_adapter.dev.parent = &pdev->dev;
+ err = i2c_bit_add_bus(&floppy_adapter);
+ if (err) {
+ dev_err(&pdev->dev, "Unable to register with I2C\n");
+ goto exit_region;
+ }
+ return 0;
+
+exit_region:
+ release_region(res->start, res->end - res->start + 1);
+ return err;
+}
+
+static int __devexit i2c_floppy_remove(struct platform_device *pdev)
+{
+ struct resource *res;
+
+ i2c_del_adapter(&floppy_adapter);
+
+ res = platform_get_resource(pdev, IORESOURCE_IO, 0);
+ release_region(res->start, res->end - res->start + 1);
+ return 0;
+}
+
+static struct platform_driver i2c_floppy_driver = {
+ .driver = {
+ .owner = THIS_MODULE,
+ .name = DRVNAME,
+ },
+ .probe = i2c_floppy_probe,
+ .remove = __devexit_p(i2c_floppy_remove),
+};
+
+static int __init i2c_floppy_device_add(u16 address)
+{
+ struct resource res = {
+ .start = address,
+ .end = address + 7,
+ .name = DRVNAME,
+ .flags = IORESOURCE_IO,
+ };
+ int err;
+
+ pdev = platform_device_alloc(DRVNAME, -1);
+ if (!pdev) {
+ err = -ENOMEM;
+ printk(KERN_ERR DRVNAME ": Device allocation failed\n");
+ goto exit;
+ }
+
+ err = platform_device_add_resources(pdev, &res, 1);
+ if (err) {
+ printk(KERN_ERR DRVNAME ": Device resource addition failed "
+ "(%d)\n", err);
+ goto exit_device_put;
+ }
+
+ err = platform_device_add(pdev);
+ if (err) {
+ printk(KERN_ERR DRVNAME ": Device addition failed (%d)\n",
+ err);
+ goto exit_device_put;
+ }
+
+ return 0;
+
+exit_device_put:
+ platform_device_put(pdev);
+exit:
+ return err;
+}
+
+static int __init i2c_floppy_init(void)
+{
+ int err;
+
+ if (base == 0) {
+ pr_info(DRVNAME ": using default base 0x%x\n", DEFAULT_BASE);
+ base = DEFAULT_BASE;
+ }
+
+ /* Sets global pdev as a side effect */
+ err = i2c_floppy_device_add(base);
+ if (err)
+ goto exit;
+
+ err = platform_driver_register(&i2c_floppy_driver);
+ if (err)
+ goto exit_device;
+
+ return 0;
+
+exit_device:
+ platform_device_unregister(pdev);
+exit:
+ return err;
+}
+
+static void __exit i2c_floppy_exit(void)
+{
+ platform_driver_unregister(&i2c_floppy_driver);
+ platform_device_unregister(pdev);
+}
+
+
+MODULE_AUTHOR("Herbert Poetzl <[EMAIL PROTECTED]>");
+MODULE_DESCRIPTION("I2C bus over floppy controller");
+MODULE_LICENSE("GPL");
+
+module_init(i2c_floppy_init);
+module_exit(i2c_floppy_exit);
diff -NurpP --minimal linux-2.6.27-rc3/drivers/i2c/busses/Kconfig
linux-2.6.27-rc3-fi2c-v0.2/drivers/i2c/busses/Kconfig
--- linux-2.6.27-rc3/drivers/i2c/busses/Kconfig 2008-08-15 21:19:24.000000000
+0200
+++ linux-2.6.27-rc3-fi2c-v0.2/drivers/i2c/busses/Kconfig 2008-08-18
03:46:31.000000000 +0200
@@ -490,6 +490,22 @@ config I2C_VERSATILE
comment "External I2C/SMBus adapter drivers"
+config I2C_FLOPPY
+ tristate "Floppy controller adapter"
+ select I2C_ALGOBIT
+ default n
+ help
+ This supports a simple do-it-yourself floppy controller to
+ I2C adapters using the motor control lines for SDA and SCL,
+ and the drive change input for SDA readback.
+
+ This support is also available as a module. If so, the module
+ will be called i2c-floppy.
+
+ If you do not have such a device, and do not plan to build one,
+ it's safe to say N here. Do not say Y here and to the floppy
+ driver unless you know exactly what you are doing.
+
config I2C_PARPORT
tristate "Parallel port adapter"
depends on PARPORT
diff -NurpP --minimal linux-2.6.27-rc3/drivers/i2c/busses/Makefile
linux-2.6.27-rc3-fi2c-v0.2/drivers/i2c/busses/Makefile
--- linux-2.6.27-rc3/drivers/i2c/busses/Makefile 2008-08-15
21:19:24.000000000 +0200
+++ linux-2.6.27-rc3-fi2c-v0.2/drivers/i2c/busses/Makefile 2008-08-18
03:46:42.000000000 +0200
@@ -48,6 +48,7 @@ obj-$(CONFIG_I2C_SIMTEC) += i2c-simtec.o
obj-$(CONFIG_I2C_VERSATILE) += i2c-versatile.o
# External I2C/SMBus adapter drivers
+obj-$(CONFIG_I2C_FLOPPY) += i2c-floppy.o
obj-$(CONFIG_I2C_PARPORT) += i2c-parport.o
obj-$(CONFIG_I2C_PARPORT_LIGHT) += i2c-parport-light.o
obj-$(CONFIG_I2C_TAOS_EVM) += i2c-taos-evm.o
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