]> www.pilppa.org Git - linux-2.6-omap-h63xx.git/commitdiff
Add c2 port support
authorRodolfo Giometti <giometti@linux.it>
Wed, 12 Nov 2008 21:27:12 +0000 (13:27 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Thu, 13 Nov 2008 01:17:18 +0000 (17:17 -0800)
C2port implements a two wire serial communication protocol (bit
banging) designed to enable in-system programming, debugging, and
boundary-scan testing on low pin-count Silicon Labs devices.

Currently this code supports only flash programming through sysfs
interface but extensions shoud be easy to add.

Signed-off-by: Rodolfo Giometti <giometti@linux.it>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Documentation/ABI/testing/sysfs-c2port [new file with mode: 0644]
Documentation/c2port.txt [new file with mode: 0644]
drivers/misc/Kconfig
drivers/misc/Makefile
drivers/misc/c2port/Kconfig [new file with mode: 0644]
drivers/misc/c2port/Makefile [new file with mode: 0644]
drivers/misc/c2port/core.c [new file with mode: 0644]
include/linux/c2port.h [new file with mode: 0644]

diff --git a/Documentation/ABI/testing/sysfs-c2port b/Documentation/ABI/testing/sysfs-c2port
new file mode 100644 (file)
index 0000000..716cffc
--- /dev/null
@@ -0,0 +1,88 @@
+What:          /sys/class/c2port/
+Date:          October 2008
+Contact:       Rodolfo Giometti <giometti@linux.it>
+Description:
+               The /sys/class/c2port/ directory will contain files and
+               directories that will provide a unified interface to
+               the C2 port interface.
+
+What:          /sys/class/c2port/c2portX
+Date:          October 2008
+Contact:       Rodolfo Giometti <giometti@linux.it>
+Description:
+               The /sys/class/c2port/c2portX/ directory is related to X-th
+               C2 port into the system. Each directory will contain files to
+               manage and control its C2 port.
+
+What:          /sys/class/c2port/c2portX/access
+Date:          October 2008
+Contact:       Rodolfo Giometti <giometti@linux.it>
+Description:
+               The /sys/class/c2port/c2portX/access file enable the access
+               to the C2 port from the system. No commands can be sent
+               till this entry is set to 0.
+
+What:          /sys/class/c2port/c2portX/dev_id
+Date:          October 2008
+Contact:       Rodolfo Giometti <giometti@linux.it>
+Description:
+               The /sys/class/c2port/c2portX/dev_id file show the device ID
+               of the connected micro.
+
+What:          /sys/class/c2port/c2portX/flash_access
+Date:          October 2008
+Contact:       Rodolfo Giometti <giometti@linux.it>
+Description:
+               The /sys/class/c2port/c2portX/flash_access file enable the
+               access to the on-board flash of the connected micro.
+               No commands can be sent till this entry is set to 0.
+
+What:          /sys/class/c2port/c2portX/flash_block_size
+Date:          October 2008
+Contact:       Rodolfo Giometti <giometti@linux.it>
+Description:
+               The /sys/class/c2port/c2portX/flash_block_size file show
+               the on-board flash block size of the connected micro.
+
+What:          /sys/class/c2port/c2portX/flash_blocks_num
+Date:          October 2008
+Contact:       Rodolfo Giometti <giometti@linux.it>
+Description:
+               The /sys/class/c2port/c2portX/flash_blocks_num file show
+               the on-board flash blocks number of the connected micro.
+
+What:          /sys/class/c2port/c2portX/flash_data
+Date:          October 2008
+Contact:       Rodolfo Giometti <giometti@linux.it>
+Description:
+               The /sys/class/c2port/c2portX/flash_data file export
+               the content of the on-board flash of the connected micro.
+
+What:          /sys/class/c2port/c2portX/flash_erase
+Date:          October 2008
+Contact:       Rodolfo Giometti <giometti@linux.it>
+Description:
+               The /sys/class/c2port/c2portX/flash_erase file execute
+               the "erase" command on the on-board flash of the connected
+               micro.
+
+What:          /sys/class/c2port/c2portX/flash_erase
+Date:          October 2008
+Contact:       Rodolfo Giometti <giometti@linux.it>
+Description:
+               The /sys/class/c2port/c2portX/flash_erase file show the
+               on-board flash size of the connected micro.
+
+What:          /sys/class/c2port/c2portX/reset
+Date:          October 2008
+Contact:       Rodolfo Giometti <giometti@linux.it>
+Description:
+               The /sys/class/c2port/c2portX/reset file execute a "reset"
+               command on the connected micro.
+
+What:          /sys/class/c2port/c2portX/rev_id
+Date:          October 2008
+Contact:       Rodolfo Giometti <giometti@linux.it>
+Description:
+               The /sys/class/c2port/c2portX/rev_id file show the revision ID
+               of the connected micro.
diff --git a/Documentation/c2port.txt b/Documentation/c2port.txt
new file mode 100644 (file)
index 0000000..d9bf93e
--- /dev/null
@@ -0,0 +1,90 @@
+                       C2 port support
+                       ---------------
+
+(C) Copyright 2007 Rodolfo Giometti <giometti@enneenne.com>
+
+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.
+
+
+
+Overview
+--------
+
+This driver implements the support for Linux of Silicon Labs (Silabs)
+C2 Interface used for in-system programming of micro controllers.
+
+By using this driver you can reprogram the in-system flash without EC2
+or EC3 debug adapter. This solution is also useful in those systems
+where the micro controller is connected via special GPIOs pins.
+
+References
+----------
+
+The C2 Interface main references are at (http://www.silabs.com)
+Silicon Laboratories site], see:
+
+- AN127: FLASH Programming via the C2 Interface at
+http://www.silabs.com/public/documents/tpub_doc/anote/Microcontrollers/Small_Form_Factor/en/an127.pdf, and
+
+- C2 Specification at
+http://www.silabs.com/public/documents/tpub_doc/spec/Microcontrollers/en/C2spec.pdf,
+
+however it implements a two wire serial communication protocol (bit
+banging) designed to enable in-system programming, debugging, and
+boundary-scan testing on low pin-count Silicon Labs devices. Currently
+this code supports only flash programming but extensions are easy to
+add.
+
+Using the driver
+----------------
+
+Once the driver is loaded you can use sysfs support to get C2port's
+info or read/write in-system flash.
+
+# ls /sys/class/c2port/c2port0/
+access            flash_block_size  flash_erase       rev_id
+dev_id            flash_blocks_num  flash_size        subsystem/
+flash_access      flash_data        reset             uevent
+
+Initially the C2port access is disabled since you hardware may have
+such lines multiplexed with other devices so, to get access to the
+C2port, you need the command:
+
+# echo 1 > /sys/class/c2port/c2port0/access
+
+after that you should read the device ID and revision ID of the
+connected micro controller:
+
+# cat /sys/class/c2port/c2port0/dev_id
+8
+# cat /sys/class/c2port/c2port0/rev_id
+1
+
+However, for security reasons, the in-system flash access in not
+enabled yet, to do so you need the command:
+
+# echo 1 > /sys/class/c2port/c2port0/flash_access
+
+After that you can read the whole flash:
+
+# cat /sys/class/c2port/c2port0/flash_data > image
+
+erase it:
+
+# echo 1 > /sys/class/c2port/c2port0/flash_erase
+
+and write it:
+
+# cat image > /sys/class/c2port/c2port0/flash_data
+
+after writing you have to reset the device to execute the new code:
+
+# echo 1 > /sys/class/c2port/c2port0/reset
index dcac7ca76937dcfd14bd5f60f1d0d8e82a4c6ad4..fee7304102af8158ca3882bccb854f0f6fcb2bbe 100644 (file)
@@ -498,4 +498,6 @@ config SGI_GRU_DEBUG
        This option enables addition debugging code for the SGI GRU driver. If
        you are unsure, say N.
 
        This option enables addition debugging code for the SGI GRU driver. If
        you are unsure, say N.
 
+source "drivers/misc/c2port/Kconfig"
+
 endif # MISC_DEVICES
 endif # MISC_DEVICES
index bb14633d13628d8ec89a8d5fda60426cf50eed30..817f7f5ab3bd2c21476033c195dbba93bf58d05b 100644 (file)
@@ -32,3 +32,4 @@ obj-$(CONFIG_KGDB_TESTS)      += kgdbts.o
 obj-$(CONFIG_SGI_XP)           += sgi-xp/
 obj-$(CONFIG_SGI_GRU)          += sgi-gru/
 obj-$(CONFIG_HP_ILO)           += hpilo.o
 obj-$(CONFIG_SGI_XP)           += sgi-xp/
 obj-$(CONFIG_SGI_GRU)          += sgi-gru/
 obj-$(CONFIG_HP_ILO)           += hpilo.o
+obj-$(CONFIG_C2PORT)           += c2port/
diff --git a/drivers/misc/c2port/Kconfig b/drivers/misc/c2port/Kconfig
new file mode 100644 (file)
index 0000000..f1bad2b
--- /dev/null
@@ -0,0 +1,24 @@
+#
+# C2 port devices
+#
+
+menuconfig C2PORT
+       tristate "Silicon Labs C2 port support (EXPERIMENTAL)"
+       depends on EXPERIMENTAL
+       default no
+       help
+         This option enables support for Silicon Labs C2 port used to
+         program Silicon micro controller chips (and other 8051 compatible).
+
+         If your board have no such micro controllers you don't need this
+         interface at all.
+
+         To compile this driver as a module, choose M here: the module will
+         be called c2port_core. Note that you also need a client module
+         usually called c2port-*.
+
+         If you are not sure, say N here.
+
+if C2PORT
+
+endif # C2PORT
diff --git a/drivers/misc/c2port/Makefile b/drivers/misc/c2port/Makefile
new file mode 100644 (file)
index 0000000..3c610a2
--- /dev/null
@@ -0,0 +1 @@
+obj-$(CONFIG_C2PORT)           += core.o
diff --git a/drivers/misc/c2port/core.c b/drivers/misc/c2port/core.c
new file mode 100644 (file)
index 0000000..976b35d
--- /dev/null
@@ -0,0 +1,1002 @@
+/*
+ *  Silicon Labs C2 port core Linux support
+ *
+ *  Copyright (c) 2007 Rodolfo Giometti <giometti@linux.it>
+ *  Copyright (c) 2007 Eurotech S.p.A. <info@eurotech.it>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/ctype.h>
+#include <linux/delay.h>
+#include <linux/idr.h>
+
+#include <linux/c2port.h>
+
+#define DRIVER_NAME             "c2port"
+#define DRIVER_VERSION          "0.51.0"
+
+static DEFINE_SPINLOCK(c2port_idr_lock);
+static DEFINE_IDR(c2port_idr);
+
+/*
+ * Local variables
+ */
+
+static struct class *c2port_class;
+
+/*
+ * C2 registers & commands defines
+ */
+
+/* C2 registers */
+#define C2PORT_DEVICEID                0x00
+#define C2PORT_REVID           0x01
+#define C2PORT_FPCTL           0x02
+#define C2PORT_FPDAT           0xB4
+
+/* C2 interface commands */
+#define C2PORT_GET_VERSION     0x01
+#define C2PORT_DEVICE_ERASE    0x03
+#define C2PORT_BLOCK_READ      0x06
+#define C2PORT_BLOCK_WRITE     0x07
+#define C2PORT_PAGE_ERASE      0x08
+
+/* C2 status return codes */
+#define C2PORT_INVALID_COMMAND 0x00
+#define C2PORT_COMMAND_FAILED  0x02
+#define C2PORT_COMMAND_OK      0x0d
+
+/*
+ * C2 port low level signal managements
+ */
+
+static void c2port_reset(struct c2port_device *dev)
+{
+       struct c2port_ops *ops = dev->ops;
+
+       /* To reset the device we have to keep clock line low for at least
+        * 20us.
+        */
+       local_irq_disable();
+       ops->c2ck_set(dev, 0);
+       udelay(25);
+       ops->c2ck_set(dev, 1);
+       local_irq_enable();
+
+       udelay(1);
+}
+
+static void c2port_strobe_ck(struct c2port_device *dev)
+{
+       struct c2port_ops *ops = dev->ops;
+
+       /* During hi-low-hi transition we disable local IRQs to avoid
+        * interructions since C2 port specification says that it must be
+        * shorter than 5us, otherwise the microcontroller may consider
+        * it as a reset signal!
+        */
+       local_irq_disable();
+       ops->c2ck_set(dev, 0);
+       udelay(1);
+       ops->c2ck_set(dev, 1);
+       local_irq_enable();
+
+       udelay(1);
+}
+
+/*
+ * C2 port basic functions
+ */
+
+static void c2port_write_ar(struct c2port_device *dev, u8 addr)
+{
+       struct c2port_ops *ops = dev->ops;
+       int i;
+
+       /* START field */
+       c2port_strobe_ck(dev);
+
+       /* INS field (11b, LSB first) */
+       ops->c2d_dir(dev, 0);
+       ops->c2d_set(dev, 1);
+       c2port_strobe_ck(dev);
+       ops->c2d_set(dev, 1);
+       c2port_strobe_ck(dev);
+
+       /* ADDRESS field */
+       for (i = 0; i < 8; i++) {
+               ops->c2d_set(dev, addr & 0x01);
+               c2port_strobe_ck(dev);
+
+               addr >>= 1;
+       }
+
+       /* STOP field */
+       ops->c2d_dir(dev, 1);
+       c2port_strobe_ck(dev);
+}
+
+static int c2port_read_ar(struct c2port_device *dev, u8 *addr)
+{
+       struct c2port_ops *ops = dev->ops;
+       int i;
+
+       /* START field */
+       c2port_strobe_ck(dev);
+
+       /* INS field (10b, LSB first) */
+       ops->c2d_dir(dev, 0);
+       ops->c2d_set(dev, 0);
+       c2port_strobe_ck(dev);
+       ops->c2d_set(dev, 1);
+       c2port_strobe_ck(dev);
+
+       /* ADDRESS field */
+       ops->c2d_dir(dev, 1);
+       *addr = 0;
+       for (i = 0; i < 8; i++) {
+               *addr >>= 1;    /* shift in 8-bit ADDRESS field LSB first */
+
+               c2port_strobe_ck(dev);
+               if (ops->c2d_get(dev))
+                       *addr |= 0x80;
+       }
+
+       /* STOP field */
+       c2port_strobe_ck(dev);
+
+       return 0;
+}
+
+static int c2port_write_dr(struct c2port_device *dev, u8 data)
+{
+       struct c2port_ops *ops = dev->ops;
+       int timeout, i;
+
+       /* START field */
+       c2port_strobe_ck(dev);
+
+       /* INS field (01b, LSB first) */
+       ops->c2d_dir(dev, 0);
+       ops->c2d_set(dev, 1);
+       c2port_strobe_ck(dev);
+       ops->c2d_set(dev, 0);
+       c2port_strobe_ck(dev);
+
+       /* LENGTH field (00b, LSB first -> 1 byte) */
+       ops->c2d_set(dev, 0);
+       c2port_strobe_ck(dev);
+       ops->c2d_set(dev, 0);
+       c2port_strobe_ck(dev);
+
+       /* DATA field */
+       for (i = 0; i < 8; i++) {
+               ops->c2d_set(dev, data & 0x01);
+               c2port_strobe_ck(dev);
+
+               data >>= 1;
+       }
+
+       /* WAIT field */
+       ops->c2d_dir(dev, 1);
+       timeout = 20;
+       do {
+               c2port_strobe_ck(dev);
+               if (ops->c2d_get(dev))
+                       break;
+
+               udelay(1);
+       } while (--timeout > 0);
+       if (timeout == 0)
+               return -EIO;
+
+       /* STOP field */
+       c2port_strobe_ck(dev);
+
+       return 0;
+}
+
+static int c2port_read_dr(struct c2port_device *dev, u8 *data)
+{
+       struct c2port_ops *ops = dev->ops;
+       int timeout, i;
+
+       /* START field */
+       c2port_strobe_ck(dev);
+
+       /* INS field (00b, LSB first) */
+       ops->c2d_dir(dev, 0);
+       ops->c2d_set(dev, 0);
+       c2port_strobe_ck(dev);
+       ops->c2d_set(dev, 0);
+       c2port_strobe_ck(dev);
+
+       /* LENGTH field (00b, LSB first -> 1 byte) */
+       ops->c2d_set(dev, 0);
+       c2port_strobe_ck(dev);
+       ops->c2d_set(dev, 0);
+       c2port_strobe_ck(dev);
+
+       /* WAIT field */
+       ops->c2d_dir(dev, 1);
+       timeout = 20;
+       do {
+               c2port_strobe_ck(dev);
+               if (ops->c2d_get(dev))
+                       break;
+
+               udelay(1);
+       } while (--timeout > 0);
+       if (timeout == 0)
+               return -EIO;
+
+       /* DATA field */
+       *data = 0;
+       for (i = 0; i < 8; i++) {
+               *data >>= 1;    /* shift in 8-bit DATA field LSB first */
+
+               c2port_strobe_ck(dev);
+               if (ops->c2d_get(dev))
+                       *data |= 0x80;
+       }
+
+       /* STOP field */
+       c2port_strobe_ck(dev);
+
+       return 0;
+}
+
+static int c2port_poll_in_busy(struct c2port_device *dev)
+{
+       u8 addr;
+       int ret, timeout = 20;
+
+       do {
+               ret = (c2port_read_ar(dev, &addr));
+               if (ret < 0)
+                       return -EIO;
+
+               if (!(addr & 0x02))
+                       break;
+
+               udelay(1);
+       } while (--timeout > 0);
+       if (timeout == 0)
+               return -EIO;
+
+       return 0;
+}
+
+static int c2port_poll_out_ready(struct c2port_device *dev)
+{
+       u8 addr;
+       int ret, timeout = 10000; /* erase flash needs long time... */
+
+       do {
+               ret = (c2port_read_ar(dev, &addr));
+               if (ret < 0)
+                       return -EIO;
+
+               if (addr & 0x01)
+                       break;
+
+               udelay(1);
+       } while (--timeout > 0);
+       if (timeout == 0)
+               return -EIO;
+
+       return 0;
+}
+
+/*
+ * sysfs methods
+ */
+
+static ssize_t c2port_show_name(struct device *dev,
+                               struct device_attribute *attr, char *buf)
+{
+       struct c2port_device *c2dev = dev_get_drvdata(dev);
+
+       return sprintf(buf, "%s\n", c2dev->name);
+}
+
+static ssize_t c2port_show_flash_blocks_num(struct device *dev,
+                               struct device_attribute *attr, char *buf)
+{
+       struct c2port_device *c2dev = dev_get_drvdata(dev);
+       struct c2port_ops *ops = c2dev->ops;
+
+       return sprintf(buf, "%d\n", ops->blocks_num);
+}
+
+static ssize_t c2port_show_flash_block_size(struct device *dev,
+                               struct device_attribute *attr, char *buf)
+{
+       struct c2port_device *c2dev = dev_get_drvdata(dev);
+       struct c2port_ops *ops = c2dev->ops;
+
+       return sprintf(buf, "%d\n", ops->block_size);
+}
+
+static ssize_t c2port_show_flash_size(struct device *dev,
+                               struct device_attribute *attr, char *buf)
+{
+       struct c2port_device *c2dev = dev_get_drvdata(dev);
+       struct c2port_ops *ops = c2dev->ops;
+
+       return sprintf(buf, "%d\n", ops->blocks_num * ops->block_size);
+}
+
+static ssize_t c2port_show_access(struct device *dev,
+                               struct device_attribute *attr, char *buf)
+{
+       struct c2port_device *c2dev = dev_get_drvdata(dev);
+
+       return sprintf(buf, "%d\n", c2dev->access);
+}
+
+static ssize_t c2port_store_access(struct device *dev,
+                               struct device_attribute *attr,
+                               const char *buf, size_t count)
+{
+       struct c2port_device *c2dev = dev_get_drvdata(dev);
+       struct c2port_ops *ops = c2dev->ops;
+       int status, ret;
+
+       ret = sscanf(buf, "%d", &status);
+       if (ret != 1)
+               return -EINVAL;
+
+       mutex_lock(&c2dev->mutex);
+
+       c2dev->access = !!status;
+
+       /* If access is "on" clock should be HIGH _before_ setting the line
+        * as output and data line should be set as INPUT anyway */
+       if (c2dev->access)
+               ops->c2ck_set(c2dev, 1);
+       ops->access(c2dev, c2dev->access);
+       if (c2dev->access)
+               ops->c2d_dir(c2dev, 1);
+
+       mutex_unlock(&c2dev->mutex);
+
+       return count;
+}
+
+static ssize_t c2port_store_reset(struct device *dev,
+                               struct device_attribute *attr,
+                               const char *buf, size_t count)
+{
+       struct c2port_device *c2dev = dev_get_drvdata(dev);
+
+       /* Check the device access status */
+       if (!c2dev->access)
+               return -EBUSY;
+
+       mutex_lock(&c2dev->mutex);
+
+       c2port_reset(c2dev);
+       c2dev->flash_access = 0;
+
+       mutex_unlock(&c2dev->mutex);
+
+       return count;
+}
+
+static ssize_t __c2port_show_dev_id(struct c2port_device *dev, char *buf)
+{
+       u8 data;
+       int ret;
+
+       /* Select DEVICEID register for C2 data register accesses */
+       c2port_write_ar(dev, C2PORT_DEVICEID);
+
+       /* Read and return the device ID register */
+       ret = c2port_read_dr(dev, &data);
+       if (ret < 0)
+               return ret;
+
+       return sprintf(buf, "%d\n", data);
+}
+
+static ssize_t c2port_show_dev_id(struct device *dev,
+                               struct device_attribute *attr, char *buf)
+{
+       struct c2port_device *c2dev = dev_get_drvdata(dev);
+       ssize_t ret;
+
+       /* Check the device access status */
+       if (!c2dev->access)
+               return -EBUSY;
+
+       mutex_lock(&c2dev->mutex);
+       ret = __c2port_show_dev_id(c2dev, buf);
+       mutex_unlock(&c2dev->mutex);
+
+       if (ret < 0)
+               dev_err(dev, "cannot read from %s\n", c2dev->name);
+
+       return ret;
+}
+
+static ssize_t __c2port_show_rev_id(struct c2port_device *dev, char *buf)
+{
+       u8 data;
+       int ret;
+
+       /* Select REVID register for C2 data register accesses */
+       c2port_write_ar(dev, C2PORT_REVID);
+
+       /* Read and return the revision ID register */
+       ret = c2port_read_dr(dev, &data);
+       if (ret < 0)
+               return ret;
+
+       return sprintf(buf, "%d\n", data);
+}
+
+static ssize_t c2port_show_rev_id(struct device *dev,
+                               struct device_attribute *attr, char *buf)
+{
+       struct c2port_device *c2dev = dev_get_drvdata(dev);
+       ssize_t ret;
+
+       /* Check the device access status */
+       if (!c2dev->access)
+               return -EBUSY;
+
+       mutex_lock(&c2dev->mutex);
+       ret = __c2port_show_rev_id(c2dev, buf);
+       mutex_unlock(&c2dev->mutex);
+
+       if (ret < 0)
+               dev_err(c2dev->dev, "cannot read from %s\n", c2dev->name);
+
+       return ret;
+}
+
+static ssize_t c2port_show_flash_access(struct device *dev,
+                               struct device_attribute *attr, char *buf)
+{
+       struct c2port_device *c2dev = dev_get_drvdata(dev);
+
+       return sprintf(buf, "%d\n", c2dev->flash_access);
+}
+
+static ssize_t __c2port_store_flash_access(struct c2port_device *dev,
+                                               int status)
+{
+       int ret;
+
+       /* Check the device access status */
+       if (!dev->access)
+               return -EBUSY;
+
+       dev->flash_access = !!status;
+
+       /* If flash_access is off we have nothing to do... */
+       if (dev->flash_access == 0)
+               return 0;
+
+       /* Target the C2 flash programming control register for C2 data
+        * register access */
+       c2port_write_ar(dev, C2PORT_FPCTL);
+
+       /* Write the first keycode to enable C2 Flash programming */
+       ret = c2port_write_dr(dev, 0x02);
+       if (ret < 0)
+               return ret;
+
+       /* Write the second keycode to enable C2 Flash programming */
+       ret = c2port_write_dr(dev, 0x01);
+       if (ret < 0)
+               return ret;
+
+       /* Delay for at least 20ms to ensure the target is ready for
+        * C2 flash programming */
+       mdelay(25);
+
+       return 0;
+}
+
+static ssize_t c2port_store_flash_access(struct device *dev,
+                               struct device_attribute *attr,
+                               const char *buf, size_t count)
+{
+       struct c2port_device *c2dev = dev_get_drvdata(dev);
+       int status;
+       ssize_t ret;
+
+       ret = sscanf(buf, "%d", &status);
+       if (ret != 1)
+               return -EINVAL;
+
+       mutex_lock(&c2dev->mutex);
+       ret = __c2port_store_flash_access(c2dev, status);
+       mutex_unlock(&c2dev->mutex);
+
+       if (ret < 0) {
+               dev_err(c2dev->dev, "cannot enable %s flash programming\n",
+                       c2dev->name);
+               return ret;
+       }
+
+       return count;
+}
+
+static ssize_t __c2port_write_flash_erase(struct c2port_device *dev)
+{
+       u8 status;
+       int ret;
+
+       /* Target the C2 flash programming data register for C2 data register
+        * access.
+        */
+       c2port_write_ar(dev, C2PORT_FPDAT);
+
+       /* Send device erase command */
+       c2port_write_dr(dev, C2PORT_DEVICE_ERASE);
+
+       /* Wait for input acknowledge */
+       ret = c2port_poll_in_busy(dev);
+       if (ret < 0)
+               return ret;
+
+       /* Should check status before starting FLASH access sequence */
+
+       /* Wait for status information */
+       ret = c2port_poll_out_ready(dev);
+       if (ret < 0)
+               return ret;
+
+       /* Read flash programming interface status */
+       ret = c2port_read_dr(dev, &status);
+       if (ret < 0)
+               return ret;
+       if (status != C2PORT_COMMAND_OK)
+               return -EBUSY;
+
+       /* Send a three-byte arming sequence to enable the device erase.
+        * If the sequence is not received correctly, the command will be
+        * ignored.
+        * Sequence is: 0xde, 0xad, 0xa5.
+        */
+       c2port_write_dr(dev, 0xde);
+       ret = c2port_poll_in_busy(dev);
+       if (ret < 0)
+               return ret;
+       c2port_write_dr(dev, 0xad);
+       ret = c2port_poll_in_busy(dev);
+       if (ret < 0)
+               return ret;
+       c2port_write_dr(dev, 0xa5);
+       ret = c2port_poll_in_busy(dev);
+       if (ret < 0)
+               return ret;
+
+       ret = c2port_poll_out_ready(dev);
+       if (ret < 0)
+               return ret;
+
+       return 0;
+}
+
+static ssize_t c2port_store_flash_erase(struct device *dev,
+                               struct device_attribute *attr,
+                               const char *buf, size_t count)
+{
+       struct c2port_device *c2dev = dev_get_drvdata(dev);
+       int ret;
+
+       /* Check the device and flash access status */
+       if (!c2dev->access || !c2dev->flash_access)
+               return -EBUSY;
+
+       mutex_lock(&c2dev->mutex);
+       ret = __c2port_write_flash_erase(c2dev);
+       mutex_unlock(&c2dev->mutex);
+
+       if (ret < 0) {
+               dev_err(c2dev->dev, "cannot erase %s flash\n", c2dev->name);
+               return ret;
+       }
+
+       return count;
+}
+
+static ssize_t __c2port_read_flash_data(struct c2port_device *dev,
+                               char *buffer, loff_t offset, size_t count)
+{
+       struct c2port_ops *ops = dev->ops;
+       u8 status, nread = 128;
+       int i, ret;
+
+       /* Check for flash end */
+       if (offset >= ops->block_size * ops->blocks_num)
+               return 0;
+
+       if (ops->block_size * ops->blocks_num - offset < nread)
+               nread = ops->block_size * ops->blocks_num - offset;
+       if (count < nread)
+               nread = count;
+       if (nread == 0)
+               return nread;
+
+       /* Target the C2 flash programming data register for C2 data register
+        * access */
+       c2port_write_ar(dev, C2PORT_FPDAT);
+
+       /* Send flash block read command */
+       c2port_write_dr(dev, C2PORT_BLOCK_READ);
+
+       /* Wait for input acknowledge */
+       ret = c2port_poll_in_busy(dev);
+       if (ret < 0)
+               return ret;
+
+       /* Should check status before starting FLASH access sequence */
+
+       /* Wait for status information */
+       ret = c2port_poll_out_ready(dev);
+       if (ret < 0)
+               return ret;
+
+       /* Read flash programming interface status */
+       ret = c2port_read_dr(dev, &status);
+       if (ret < 0)
+               return ret;
+       if (status != C2PORT_COMMAND_OK)
+               return -EBUSY;
+
+       /* Send address high byte */
+       c2port_write_dr(dev, offset >> 8);
+       ret = c2port_poll_in_busy(dev);
+       if (ret < 0)
+               return ret;
+
+       /* Send address low byte */
+       c2port_write_dr(dev, offset & 0x00ff);
+       ret = c2port_poll_in_busy(dev);
+       if (ret < 0)
+               return ret;
+
+       /* Send address block size */
+       c2port_write_dr(dev, nread);
+       ret = c2port_poll_in_busy(dev);
+       if (ret < 0)
+               return ret;
+
+       /* Should check status before reading FLASH block */
+
+       /* Wait for status information */
+       ret = c2port_poll_out_ready(dev);
+       if (ret < 0)
+               return ret;
+
+       /* Read flash programming interface status */
+       ret = c2port_read_dr(dev, &status);
+       if (ret < 0)
+               return ret;
+       if (status != C2PORT_COMMAND_OK)
+               return -EBUSY;
+
+       /* Read flash block */
+       for (i = 0; i < nread; i++) {
+               ret = c2port_poll_out_ready(dev);
+               if (ret < 0)
+                       return ret;
+
+               ret = c2port_read_dr(dev, buffer+i);
+               if (ret < 0)
+                       return ret;
+       }
+
+       return nread;
+}
+
+static ssize_t c2port_read_flash_data(struct kobject *kobj,
+                               struct bin_attribute *attr,
+                               char *buffer, loff_t offset, size_t count)
+{
+       struct c2port_device *c2dev =
+                       dev_get_drvdata(container_of(kobj,
+                                               struct device, kobj));
+       ssize_t ret;
+
+       /* Check the device and flash access status */
+       if (!c2dev->access || !c2dev->flash_access)
+               return -EBUSY;
+
+       mutex_lock(&c2dev->mutex);
+       ret = __c2port_read_flash_data(c2dev, buffer, offset, count);
+       mutex_unlock(&c2dev->mutex);
+
+       if (ret < 0)
+               dev_err(c2dev->dev, "cannot read %s flash\n", c2dev->name);
+
+       return ret;
+}
+
+static ssize_t __c2port_write_flash_data(struct c2port_device *dev,
+                               char *buffer, loff_t offset, size_t count)
+{
+       struct c2port_ops *ops = dev->ops;
+       u8 status, nwrite = 128;
+       int i, ret;
+
+       if (nwrite > count)
+               nwrite = count;
+       if (ops->block_size * ops->blocks_num - offset < nwrite)
+               nwrite = ops->block_size * ops->blocks_num - offset;
+
+       /* Check for flash end */
+       if (offset >= ops->block_size * ops->blocks_num)
+               return -EINVAL;
+
+       /* Target the C2 flash programming data register for C2 data register
+        * access */
+       c2port_write_ar(dev, C2PORT_FPDAT);
+
+       /* Send flash block write command */
+       c2port_write_dr(dev, C2PORT_BLOCK_WRITE);
+
+       /* Wait for input acknowledge */
+       ret = c2port_poll_in_busy(dev);
+       if (ret < 0)
+               return ret;
+
+       /* Should check status before starting FLASH access sequence */
+
+       /* Wait for status information */
+       ret = c2port_poll_out_ready(dev);
+       if (ret < 0)
+               return ret;
+
+       /* Read flash programming interface status */
+       ret = c2port_read_dr(dev, &status);
+       if (ret < 0)
+               return ret;
+       if (status != C2PORT_COMMAND_OK)
+               return -EBUSY;
+
+       /* Send address high byte */
+       c2port_write_dr(dev, offset >> 8);
+       ret = c2port_poll_in_busy(dev);
+       if (ret < 0)
+               return ret;
+
+       /* Send address low byte */
+       c2port_write_dr(dev, offset & 0x00ff);
+       ret = c2port_poll_in_busy(dev);
+       if (ret < 0)
+               return ret;
+
+       /* Send address block size */
+       c2port_write_dr(dev, nwrite);
+       ret = c2port_poll_in_busy(dev);
+       if (ret < 0)
+               return ret;
+
+       /* Should check status before writing FLASH block */
+
+       /* Wait for status information */
+       ret = c2port_poll_out_ready(dev);
+       if (ret < 0)
+               return ret;
+
+       /* Read flash programming interface status */
+       ret = c2port_read_dr(dev, &status);
+       if (ret < 0)
+               return ret;
+       if (status != C2PORT_COMMAND_OK)
+               return -EBUSY;
+
+       /* Write flash block */
+       for (i = 0; i < nwrite; i++) {
+               ret = c2port_write_dr(dev, *(buffer+i));
+               if (ret < 0)
+                       return ret;
+
+               ret = c2port_poll_in_busy(dev);
+               if (ret < 0)
+                       return ret;
+
+       }
+
+       /* Wait for last flash write to complete */
+       ret = c2port_poll_out_ready(dev);
+       if (ret < 0)
+               return ret;
+
+       return nwrite;
+}
+
+static ssize_t c2port_write_flash_data(struct kobject *kobj,
+                               struct bin_attribute *attr,
+                               char *buffer, loff_t offset, size_t count)
+{
+       struct c2port_device *c2dev =
+                       dev_get_drvdata(container_of(kobj,
+                                               struct device, kobj));
+       int ret;
+
+       /* Check the device access status */
+       if (!c2dev->access || !c2dev->flash_access)
+               return -EBUSY;
+
+       mutex_lock(&c2dev->mutex);
+       ret = __c2port_write_flash_data(c2dev, buffer, offset, count);
+       mutex_unlock(&c2dev->mutex);
+
+       if (ret < 0)
+               dev_err(c2dev->dev, "cannot write %s flash\n", c2dev->name);
+
+       return ret;
+}
+
+/*
+ * Class attributes
+ */
+
+static struct device_attribute c2port_attrs[] = {
+       __ATTR(name, 0444, c2port_show_name, NULL),
+       __ATTR(flash_blocks_num, 0444, c2port_show_flash_blocks_num, NULL),
+       __ATTR(flash_block_size, 0444, c2port_show_flash_block_size, NULL),
+       __ATTR(flash_size, 0444, c2port_show_flash_size, NULL),
+       __ATTR(access, 0644, c2port_show_access, c2port_store_access),
+       __ATTR(reset, 0200, NULL, c2port_store_reset),
+       __ATTR(dev_id, 0444, c2port_show_dev_id, NULL),
+       __ATTR(rev_id, 0444, c2port_show_rev_id, NULL),
+
+       __ATTR(flash_access, 0644, c2port_show_flash_access,
+                                       c2port_store_flash_access),
+       __ATTR(flash_erase, 0200, NULL, c2port_store_flash_erase),
+       __ATTR_NULL,
+};
+
+static struct bin_attribute c2port_bin_attrs = {
+       .attr   = {
+               .name   = "flash_data",
+               .mode   = 0644
+       },
+       .read   = c2port_read_flash_data,
+       .write  = c2port_write_flash_data,
+       /* .size is computed at run-time */
+};
+
+/*
+ * Exported functions
+ */
+
+struct c2port_device *c2port_device_register(char *name,
+                                       struct c2port_ops *ops, void *devdata)
+{
+       struct c2port_device *c2dev;
+       int id, ret;
+
+       if (unlikely(!ops) || unlikely(!ops->access) || \
+               unlikely(!ops->c2d_dir) || unlikely(!ops->c2ck_set) || \
+               unlikely(!ops->c2d_get) || unlikely(!ops->c2d_set))
+               return ERR_PTR(-EINVAL);
+
+       c2dev = kmalloc(sizeof(struct c2port_device), GFP_KERNEL);
+       if (unlikely(!c2dev))
+               return ERR_PTR(-ENOMEM);
+
+       ret = idr_pre_get(&c2port_idr, GFP_KERNEL);
+       if (!ret) {
+               ret = -ENOMEM;
+               goto error_idr_get_new;
+       }
+
+       spin_lock_irq(&c2port_idr_lock);
+       ret = idr_get_new(&c2port_idr, c2dev, &id);
+       spin_unlock_irq(&c2port_idr_lock);
+
+       if (ret < 0)
+               goto error_idr_get_new;
+       c2dev->id = id;
+
+       c2dev->dev = device_create(c2port_class, NULL, 0, c2dev,
+                                       "c2port%d", id);
+       if (unlikely(!c2dev->dev)) {
+               ret = -ENOMEM;
+               goto error_device_create;
+       }
+       dev_set_drvdata(c2dev->dev, c2dev);
+
+       strncpy(c2dev->name, name, C2PORT_NAME_LEN);
+       c2dev->ops = ops;
+       mutex_init(&c2dev->mutex);
+
+       /* Create binary file */
+       c2port_bin_attrs.size = ops->blocks_num * ops->block_size;
+       ret = device_create_bin_file(c2dev->dev, &c2port_bin_attrs);
+       if (unlikely(ret))
+               goto error_device_create_bin_file;
+
+       /* By default C2 port access is off */
+       c2dev->access = c2dev->flash_access = 0;
+       ops->access(c2dev, 0);
+
+       dev_info(c2dev->dev, "C2 port %s added\n", name);
+       dev_info(c2dev->dev, "%s flash has %d blocks x %d bytes "
+                               "(%d bytes total)\n",
+                               name, ops->blocks_num, ops->block_size,
+                               ops->blocks_num * ops->block_size);
+
+       return c2dev;
+
+error_device_create_bin_file:
+       device_destroy(c2port_class, 0);
+
+error_device_create:
+       spin_lock_irq(&c2port_idr_lock);
+       idr_remove(&c2port_idr, id);
+       spin_unlock_irq(&c2port_idr_lock);
+
+error_idr_get_new:
+       kfree(c2dev);
+
+       return ERR_PTR(ret);
+}
+EXPORT_SYMBOL(c2port_device_register);
+
+void c2port_device_unregister(struct c2port_device *c2dev)
+{
+       if (!c2dev)
+               return;
+
+       dev_info(c2dev->dev, "C2 port %s removed\n", c2dev->name);
+
+       device_remove_bin_file(c2dev->dev, &c2port_bin_attrs);
+       spin_lock_irq(&c2port_idr_lock);
+       idr_remove(&c2port_idr, c2dev->id);
+       spin_unlock_irq(&c2port_idr_lock);
+
+       device_destroy(c2port_class, c2dev->id);
+
+       kfree(c2dev);
+}
+EXPORT_SYMBOL(c2port_device_unregister);
+
+/*
+ * Module stuff
+ */
+
+static int __init c2port_init(void)
+{
+       printk(KERN_INFO "Silicon Labs C2 port support v. " DRIVER_VERSION
+               " - (C) 2007 Rodolfo Giometti\n");
+
+       c2port_class = class_create(THIS_MODULE, "c2port");
+       if (!c2port_class) {
+               printk(KERN_ERR "c2port: failed to allocate class\n");
+               return -ENOMEM;
+       }
+       c2port_class->dev_attrs = c2port_attrs;
+
+       return 0;
+}
+
+static void __exit c2port_exit(void)
+{
+       class_destroy(c2port_class);
+}
+
+module_init(c2port_init);
+module_exit(c2port_exit);
+
+MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
+MODULE_DESCRIPTION("Silicon Labs C2 port support v. " DRIVER_VERSION);
+MODULE_LICENSE("GPL");
diff --git a/include/linux/c2port.h b/include/linux/c2port.h
new file mode 100644 (file)
index 0000000..7b5a238
--- /dev/null
@@ -0,0 +1,65 @@
+/*
+ *  Silicon Labs C2 port Linux support
+ *
+ *  Copyright (c) 2007 Rodolfo Giometti <giometti@linux.it>
+ *  Copyright (c) 2007 Eurotech S.p.A. <info@eurotech.it>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation
+ */
+
+#include <linux/device.h>
+
+#define C2PORT_NAME_LEN                        32
+
+/*
+ * C2 port basic structs
+ */
+
+/* Main struct */
+struct c2port_ops;
+struct c2port_device {
+       unsigned int access:1;
+       unsigned int flash_access:1;
+
+       int id;
+       char name[C2PORT_NAME_LEN];
+       struct c2port_ops *ops;
+       struct mutex mutex;             /* prevent races during read/write */
+
+       struct device *dev;
+
+       void *private_data;
+};
+
+/* Basic operations */
+struct c2port_ops {
+       /* Flash layout */
+       unsigned short block_size;      /* flash block size in bytes */
+       unsigned short blocks_num;      /* flash blocks number */
+
+       /* Enable or disable the access to C2 port */
+       void (*access)(struct c2port_device *dev, int status);
+
+       /* Set C2D data line as input/output */
+       void (*c2d_dir)(struct c2port_device *dev, int dir);
+
+       /* Read/write C2D data line */
+       int (*c2d_get)(struct c2port_device *dev);
+       void (*c2d_set)(struct c2port_device *dev, int status);
+
+       /* Write C2CK clock line */
+       void (*c2ck_set)(struct c2port_device *dev, int status);
+};
+
+/*
+ * Exported functions
+ */
+
+#define to_class_dev(obj) container_of((obj), struct class_device, kobj)
+#define to_c2port_device(obj) container_of((obj), struct c2port_device, class)
+
+extern struct c2port_device *c2port_device_register(char *name,
+                                       struct c2port_ops *ops, void *devdata);
+extern void c2port_device_unregister(struct c2port_device *dev);