From 4e17e1db96474af5620e3259754df4cb1c46521c Mon Sep 17 00:00:00 2001 From: Rodolfo Giometti Date: Wed, 12 Nov 2008 13:27:12 -0800 Subject: [PATCH] Add c2 port support 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 Cc: Greg KH Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/ABI/testing/sysfs-c2port | 88 +++ Documentation/c2port.txt | 90 +++ drivers/misc/Kconfig | 2 + drivers/misc/Makefile | 1 + drivers/misc/c2port/Kconfig | 24 + drivers/misc/c2port/Makefile | 1 + drivers/misc/c2port/core.c | 1002 ++++++++++++++++++++++++ include/linux/c2port.h | 65 ++ 8 files changed, 1273 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-c2port create mode 100644 Documentation/c2port.txt create mode 100644 drivers/misc/c2port/Kconfig create mode 100644 drivers/misc/c2port/Makefile create mode 100644 drivers/misc/c2port/core.c create mode 100644 include/linux/c2port.h diff --git a/Documentation/ABI/testing/sysfs-c2port b/Documentation/ABI/testing/sysfs-c2port new file mode 100644 index 00000000000..716cffc457e --- /dev/null +++ b/Documentation/ABI/testing/sysfs-c2port @@ -0,0 +1,88 @@ +What: /sys/class/c2port/ +Date: October 2008 +Contact: Rodolfo Giometti +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 +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 +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 +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 +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 +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 +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 +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 +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 +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 +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 +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 index 00000000000..d9bf93ea439 --- /dev/null +++ b/Documentation/c2port.txt @@ -0,0 +1,90 @@ + C2 port support + --------------- + +(C) Copyright 2007 Rodolfo Giometti + +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 diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig index dcac7ca7693..fee7304102a 100644 --- a/drivers/misc/Kconfig +++ b/drivers/misc/Kconfig @@ -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. +source "drivers/misc/c2port/Kconfig" + endif # MISC_DEVICES diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile index bb14633d136..817f7f5ab3b 100644 --- a/drivers/misc/Makefile +++ b/drivers/misc/Makefile @@ -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-$(CONFIG_C2PORT) += c2port/ diff --git a/drivers/misc/c2port/Kconfig b/drivers/misc/c2port/Kconfig new file mode 100644 index 00000000000..f1bad2b4032 --- /dev/null +++ b/drivers/misc/c2port/Kconfig @@ -0,0 +1,24 @@ +# +# C2 port devices +# + +menuconfig C2PORT + tristate "Silicon Labs C2 port support (EXPERIMENTAL)" + depends on EXPERIMENTAL + default no + help + This option enables support for Silicon Labs C2 port used to + program Silicon micro controller chips (and other 8051 compatible). + + If your board have no such micro controllers you don't need this + interface at all. + + To compile this driver as a module, choose M here: the module will + be called c2port_core. Note that you also need a client module + usually called c2port-*. + + If you are not sure, say N here. + +if C2PORT + +endif # C2PORT diff --git a/drivers/misc/c2port/Makefile b/drivers/misc/c2port/Makefile new file mode 100644 index 00000000000..3c610a2ba5e --- /dev/null +++ b/drivers/misc/c2port/Makefile @@ -0,0 +1 @@ +obj-$(CONFIG_C2PORT) += core.o diff --git a/drivers/misc/c2port/core.c b/drivers/misc/c2port/core.c new file mode 100644 index 00000000000..976b35d1d03 --- /dev/null +++ b/drivers/misc/c2port/core.c @@ -0,0 +1,1002 @@ +/* + * Silicon Labs C2 port core Linux support + * + * Copyright (c) 2007 Rodolfo Giometti + * Copyright (c) 2007 Eurotech S.p.A. + * + * 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 +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +#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 "); +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 index 00000000000..7b5a2388ba6 --- /dev/null +++ b/include/linux/c2port.h @@ -0,0 +1,65 @@ +/* + * Silicon Labs C2 port Linux support + * + * Copyright (c) 2007 Rodolfo Giometti + * Copyright (c) 2007 Eurotech S.p.A. + * + * 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 + +#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); -- 2.41.0