Add JTAG bitbang driver
Signed-off-by: Wjatscheslaw Stoljarski <wjatscheslaw.stoljarski@kiwigrid.com> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
This commit is contained in:
Wjatscheslaw Stoljarski
Sascha Hauer
parent
3f96b4938c
commit
082ee53440
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@ -12,6 +12,7 @@ source "drivers/video/Kconfig"
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source "drivers/mci/Kconfig"
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source "drivers/clk/Kconfig"
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source "drivers/mfd/Kconfig"
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source "drivers/misc/Kconfig"
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source "drivers/led/Kconfig"
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source "drivers/eeprom/Kconfig"
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source "drivers/input/Kconfig"
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@ -15,5 +15,6 @@ obj-$(CONFIG_LED) += led/
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obj-y += eeprom/
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obj-$(CONFIG_PWM) += pwm/
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obj-y += input/
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obj-y += misc/
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obj-y += dma/
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obj-y += watchdog/
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@ -0,0 +1,17 @@
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#
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# Misc strange devices
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#
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menuconfig MISC_DEVICES
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bool "Misc devices "
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help
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Add support for misc strange devices
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if MISC_DEVICES
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config JTAG
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tristate "JTAG Bitbang driver"
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help
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Controls JTAG chains connected to I/O pins
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endif # MISC_DEVICES
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@ -0,0 +1,5 @@
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#
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# Makefile for misc devices that really don't fit anywhere else.
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#
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obj-$(CONFIG_JTAG) += jtag.o
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@ -0,0 +1,392 @@
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/*
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* drivers/misc/jtag.c - More infos in include/jtag.h
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*
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* Written Aug 2009 by Davide Rizzo <elpa.rizzo@gmail.com>
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*
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* Ported to barebox Jul 2012 by
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* Wjatscheslaw Stoljarski <wjatscheslaw.stoljarski@kiwigrid.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#include <fs.h>
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#include <errno.h>
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//#include <linux/list.h>
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#include <jtag.h>
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#include <gpio.h>
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#include <driver.h>
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#include <malloc.h>
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#include <common.h>
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#include <init.h>
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#include <ioctl.h>
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#define VERSION_MAJ 1
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#define VERSION_MIN 0
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/* Max devices in the jtag chain */
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#define MAX_DEVICES 16
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struct jtag_info {
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struct jtag_platdata *pdata;
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struct cdev cdev;
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unsigned int devices; /* Number of devices found in the jtag chain */
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/* Instruction register length of every device in the chain */
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unsigned int ir_len[MAX_DEVICES]; /* [devices] */
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};
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static const unsigned long bypass = 0xFFFFFFFF;
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static void pulse_tms0(const struct jtag_platdata *pdata)
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{
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gpio_set_value(pdata->gpio_tms, 0);
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gpio_set_value(pdata->gpio_tclk, 0);
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gpio_set_value(pdata->gpio_tclk, 1);
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}
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static void pulse_tms1(const struct jtag_platdata *pdata)
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{
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gpio_set_value(pdata->gpio_tms, 1);
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gpio_set_value(pdata->gpio_tclk, 0);
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gpio_set_value(pdata->gpio_tclk, 1);
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}
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static void jtag_reset(const struct jtag_platdata *pdata)
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{
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gpio_set_value(pdata->gpio_tms, 1);
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gpio_set_value(pdata->gpio_tclk, 0);
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gpio_set_value(pdata->gpio_tclk, 1);
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gpio_set_value(pdata->gpio_tclk, 0);
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gpio_set_value(pdata->gpio_tclk, 1);
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gpio_set_value(pdata->gpio_tclk, 0);
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gpio_set_value(pdata->gpio_tclk, 1);
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gpio_set_value(pdata->gpio_tclk, 0);
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gpio_set_value(pdata->gpio_tclk, 1);
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gpio_set_value(pdata->gpio_tclk, 0);
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gpio_set_value(pdata->gpio_tclk, 1);
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}
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static void jtag_output(const struct jtag_platdata *pdata,
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const unsigned long *data, unsigned int bitlen, int notlast)
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{
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unsigned int a;
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unsigned long mask;
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gpio_set_value(pdata->gpio_tms, 0);
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while (bitlen > 0) {
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for (a = *data++, mask = 0x00000001; mask != 0 && bitlen > 0;
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mask <<= 1, bitlen--) {
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gpio_set_value(pdata->gpio_tdo, (a & mask) ? 1 : 0);
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if ((bitlen == 1) && !notlast)
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gpio_set_value(pdata->gpio_tms, 1);
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gpio_set_value(pdata->gpio_tclk, 0);
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gpio_set_value(pdata->gpio_tclk, 1);
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}
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}
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}
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static int jtag_ioctl(struct cdev *inode, int cmd, void *arg)
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{
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int ret = 0;
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struct jtag_info *info = (struct jtag_info *)inode->priv;
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int devices = info->devices;
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struct jtag_cmd *jcmd = (struct jtag_cmd *)arg;
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struct jtag_platdata *pdata = info->pdata;
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if (_IOC_TYPE(cmd) != JTAG_IOC_MAGIC) return -ENOTTY;
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if (_IOC_NR(cmd) > JTAG_IOC_MAXNR) return -ENOTTY;
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switch (cmd) {
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case JTAG_GET_DEVICES:
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/* Returns how many devices found in the chain */
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ret = info->devices;
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break;
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case JTAG_GET_ID:
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/* Returns ID register of selected device */
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if ((((struct jtag_rd_id *)arg)->device < 0) ||
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(((struct jtag_rd_id *)arg)->device >= devices)) {
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ret = -EINVAL;
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break;
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}
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jtag_reset(pdata);
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pulse_tms0(pdata);
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pulse_tms1(pdata);
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pulse_tms0(pdata);
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pulse_tms0(pdata);
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while (devices-- > 0) {
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unsigned long id = 0;
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pulse_tms0(pdata);
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if (gpio_get_value(pdata->gpio_tdi)) {
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unsigned long mask;
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for (id = 1, mask = 0x00000002; (mask != 0);
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mask <<= 1) {
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pulse_tms0(pdata);
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if (gpio_get_value(pdata->gpio_tdi))
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id |= mask;
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}
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}
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if (devices == ((struct jtag_rd_id *)arg)->device) {
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((struct jtag_rd_id *)arg)->id = id;
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ret = 0;
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break;
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}
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}
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jtag_reset(pdata);
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break;
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case JTAG_SET_IR_LENGTH:
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/* Sets up IR length of one device */
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if ((jcmd->device >= 0) && (jcmd->device < devices))
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info->ir_len[jcmd->device] = jcmd->bitlen;
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else
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ret = -EINVAL;
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break;
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case JTAG_RESET:
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/* Resets all JTAG states */
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jtag_reset(pdata);
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break;
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case JTAG_IR_WR:
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/*
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* Writes Instruction Register
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* If device == -1 writes same Instruction Register in
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* all devices.
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* If device >= 0 writes Instruction Register in selected
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* device and loads BYPASS instruction in all others.
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*/
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if ((jcmd->device < -1) || (jcmd->device >= devices)) {
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ret = -EINVAL;
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break;
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}
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pulse_tms0(pdata);
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pulse_tms1(pdata);
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pulse_tms1(pdata);
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pulse_tms0(pdata);
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pulse_tms0(pdata);
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while (devices-- > 0) {
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if ((jcmd->device == -1) || (jcmd->device == devices))
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/* Loads desired instruction */
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jtag_output(pdata, jcmd->data,
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info->ir_len[devices], devices);
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else
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/* Loads BYPASS instruction */
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jtag_output(pdata, &bypass,
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info->ir_len[devices], devices);
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}
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pulse_tms1(pdata);
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pulse_tms0(pdata);
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break;
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case JTAG_DR_WR:
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/*
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* Writes Data Register of all devices
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* If device == -1 writes same Data Register in all devices.
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* If device >= 0 writes Data Register in selected device
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* and loads BYPASS instruction in all others.
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*/
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if ((jcmd->device < -1) || (jcmd->device >= devices)) {
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ret = -EINVAL;
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break;
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}
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pulse_tms0(pdata);
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pulse_tms1(pdata);
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pulse_tms0(pdata);
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pulse_tms0(pdata);
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while (devices-- > 0) {
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if ((jcmd->device == -1) || (devices == jcmd->device))
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/* Loads desired data */
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jtag_output(pdata, jcmd->data, jcmd->bitlen,
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devices);
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else
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/* Loads 1 dummy bit in BYPASS data register */
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jtag_output(pdata, &bypass, 1, devices);
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}
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pulse_tms1(pdata);
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pulse_tms0(pdata);
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break;
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case JTAG_DR_RD:
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/* Reads data register of selected device */
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if ((jcmd->device < 0) || (jcmd->device >= devices))
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ret = -EINVAL;
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else {
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unsigned long mask;
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int bitlen = jcmd->bitlen;
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unsigned long *data = jcmd->data;
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pulse_tms0(pdata);
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pulse_tms1(pdata);
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pulse_tms0(pdata);
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pulse_tms0(pdata);
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devices -= (jcmd->device + 1);
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while (devices-- > 0)
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pulse_tms0(pdata);
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while (bitlen > 0) {
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for (*data = 0, mask = 0x00000001;
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(mask != 0) && (bitlen > 0);
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mask <<= 1, bitlen--) {
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if (bitlen == 1)
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pulse_tms1(pdata);
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else
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pulse_tms0(pdata);
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if (gpio_get_value(pdata->gpio_tdi))
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*data |= mask;
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}
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data++;
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}
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pulse_tms1(pdata);
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pulse_tms0(pdata);
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}
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break;
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case JTAG_CLK:
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/* Generates arg clock pulses */
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gpio_set_value(pdata->gpio_tms, 0);
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while ((*(unsigned int *) arg)--) {
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gpio_set_value(pdata->gpio_tclk, 0);
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gpio_set_value(pdata->gpio_tclk, 1);
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}
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break;
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default:
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ret = -EFAULT;
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}
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return ret;
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}
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static struct file_operations jtag_operations = {
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.ioctl = jtag_ioctl,
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};
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static int jtag_probe(struct device_d *pdev)
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{
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int i, ret;
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struct jtag_info *info;
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struct jtag_platdata *pdata = pdev->platform_data;
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/* Setup gpio pins */
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gpio_direction_output(pdata->gpio_tms, 0);
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gpio_direction_output(pdata->gpio_tclk, 1);
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gpio_direction_output(pdata->gpio_tdo, 0);
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gpio_direction_input(pdata->gpio_tdi);
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if (pdata->use_gpio_trst) {
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/*
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* Keep fixed at 1 because some devices in the chain could
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* not use it, to reset chain use jtag_reset()
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*/
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gpio_direction_output(pdata->gpio_trst, 1);
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}
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/* Find how many devices in chain */
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jtag_reset(pdata);
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pulse_tms0(pdata);
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pulse_tms1(pdata);
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pulse_tms1(pdata);
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pulse_tms0(pdata);
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pulse_tms0(pdata);
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gpio_set_value(pdata->gpio_tdo, 1);
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/* Fills all IR with bypass instruction */
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for (i = 0; i < 32 * MAX_DEVICES; i++)
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pulse_tms0(pdata);
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pulse_tms1(pdata);
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pulse_tms1(pdata);
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pulse_tms1(pdata);
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pulse_tms0(pdata);
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pulse_tms0(pdata);
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gpio_set_value(pdata->gpio_tdo, 0);
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/* Fills all 1-bit bypass register with 0 */
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for (i = 0; i < MAX_DEVICES + 2; i++)
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pulse_tms0(pdata);
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gpio_set_value(pdata->gpio_tdo, 1);
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/* Counts chain's bit length */
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for (i = 0; i < MAX_DEVICES + 1; i++) {
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pulse_tms0(pdata);
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if (gpio_get_value(pdata->gpio_tdi))
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break;
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}
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dev_notice(pdev, "%d devices found in chain\n", i);
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/* Allocate structure with chain specific infos */
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info = xzalloc(sizeof(struct jtag_info) + sizeof(info->ir_len[0]) * i);
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info->devices = i;
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info->pdata = pdata;
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pdev->priv = info;
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info->cdev.name = JTAG_NAME;
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info->cdev.dev = pdev;
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info->cdev.ops = &jtag_operations;
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info->cdev.priv = info;
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ret = devfs_create(&info->cdev);
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if (ret)
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goto fail_devfs_create;
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return 0;
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fail_devfs_create:
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pdev->priv = NULL;
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free(info);
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return ret;
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}
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static void jtag_info(struct device_d *pdev)
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{
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int dn, ret;
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struct jtag_rd_id jid;
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struct jtag_info *info = pdev->priv;
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printf(" JTAG:\n");
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printf(" Devices found: %d\n", info->devices);
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for (dn = 0; dn < info->devices; dn++) {
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jid.device = dn;
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ret = jtag_ioctl(&info->cdev, JTAG_GET_ID, &jid);
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printf(" Device number: %d\n", dn);
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if (ret == -1)
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printf(" JTAG_GET_ID failed: %s\n", strerror(errno));
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else
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printf(" ID: 0x%lX\n", jid.id);
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}
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}
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static void jtag_remove(struct device_d *pdev)
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{
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struct jtag_info *info = (struct jtag_info *) pdev->priv;
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devfs_remove(&info->cdev);
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pdev->priv = NULL;
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free(info);
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dev_notice(pdev, "Device removed\n");
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}
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static struct driver_d jtag_driver = {
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.name = JTAG_NAME,
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.probe = jtag_probe,
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.remove = jtag_remove,
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.info = jtag_info,
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};
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static int jtag_module_init(void)
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{
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return register_driver(&jtag_driver);
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}
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device_initcall(jtag_module_init);
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MODULE_AUTHOR("Davide Rizzo <elpa.rizzo@gmail.com>");
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MODULE_AUTHOR("Wjatscheslaw Stoljarski <wjatscheslaw.stoljarski@kiwigrid.com>");
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MODULE_DESCRIPTION("JTAG bitbang driver");
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MODULE_LICENSE("GPL");
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@ -0,0 +1,109 @@
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/*
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* include/linux/jtag.h
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*
|
||||
* Written Aug 2009 by Davide Rizzo <elpa.rizzo@gmail.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.
|
||||
*
|
||||
* 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.
|
||||
*/
|
||||
|
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/*
|
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* This driver manages one or more jtag chains controlled by host pins.
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* Jtag chains must be defined during setup using jtag_platdata structs.
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* All operations must be done from user programs using ioctls to /dev/jtag
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* Typical operation sequence is:
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* - open() the device (normally /dev/jtag)
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* - ioctl JTAG_GET_DEVICES reads how many devices in the chain
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* (repeat for each chip in the chain)
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* - ioctl JTAG_GET_ID identifies the chip
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* - ioctl JTAG_SET_IR_LENGTH sets the instruction register length
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* Before accessing the data registers, instruction registers' lenghtes
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* MUST be programmed for all chips.
|
||||
* After this initialization, you can execute JTAG_IR_WR, JTAG_DR_RD, JTAG_DR_WR
|
||||
* commands in any sequence.
|
||||
*/
|
||||
|
||||
#ifndef __JTAG_H__
|
||||
#define __JTAG_H__
|
||||
|
||||
/* Controller's gpio_tdi must be connected to last device's gpio_tdo */
|
||||
/* Controller's gpio_tdo must be connected to first device's gpio_tdi */
|
||||
struct jtag_platdata {
|
||||
unsigned int gpio_tclk;
|
||||
unsigned int gpio_tms;
|
||||
unsigned int gpio_tdi;
|
||||
unsigned int gpio_tdo;
|
||||
unsigned int gpio_trst;
|
||||
int use_gpio_trst;
|
||||
};
|
||||
|
||||
#define JTAG_NAME "jtag"
|
||||
|
||||
/* structures used for passing arguments to ioctl */
|
||||
|
||||
struct jtag_rd_id {
|
||||
int device; /* Device in the chain */
|
||||
unsigned long id;
|
||||
};
|
||||
|
||||
struct jtag_cmd {
|
||||
int device; /* Device in the chain (-1 = all devices) */
|
||||
unsigned int bitlen; /* Bit length of the register to be transfered */
|
||||
unsigned long *data; /* Data to be transfered */
|
||||
};
|
||||
|
||||
/* Use 'j' as magic number */
|
||||
#define JTAG_IOC_MAGIC 'j'
|
||||
|
||||
/* ioctl commands */
|
||||
|
||||
/* Resets jtag chain status, arg is ignored */
|
||||
#define JTAG_RESET _IO(JTAG_IOC_MAGIC, 0)
|
||||
|
||||
/* Returns the number of devices in the jtag chain, arg is ignored. */
|
||||
#define JTAG_GET_DEVICES _IO(JTAG_IOC_MAGIC, 1)
|
||||
|
||||
/* arg must point to a jtag_rd_id structure.
|
||||
Fills up the id field with ID of selected device */
|
||||
#define JTAG_GET_ID _IOR(JTAG_IOC_MAGIC, 2, struct jtag_rd_id)
|
||||
|
||||
/* arg must point to a struct jtag_cmd.
|
||||
Programs the Instruction Register length of specified device at bitlen value.
|
||||
*data is ignored. */
|
||||
#define JTAG_SET_IR_LENGTH _IOW(JTAG_IOC_MAGIC, 3, struct jtag_rd_id)
|
||||
|
||||
/* arg must point to a struct jtag_cmd.
|
||||
Writes *data in the Instruction Register of selected device, and BYPASS
|
||||
instruction into Instruction Registers of all other devices in the chain.
|
||||
If device == -1, the Instruction Registers of all devices are programmed
|
||||
to the same value.
|
||||
bitlen is always ignored, before using this command you have to program all
|
||||
Instruction Register's lengthes with JTAG_SET_IR_LENGTH command. */
|
||||
#define JTAG_IR_WR _IOW(JTAG_IOC_MAGIC, 4, struct jtag_cmd)
|
||||
|
||||
/* arg must point to a struct jtag_cmd.
|
||||
Reads data register of selected device, with length bitlen */
|
||||
#define JTAG_DR_RD _IOR(JTAG_IOC_MAGIC, 5, struct jtag_cmd)
|
||||
|
||||
/* arg must point to a struct jtag_cmd.
|
||||
Writes data register of selected device, with length bitlen.
|
||||
If device == -1, writes same data on all devices. */
|
||||
#define JTAG_DR_WR _IOW(JTAG_IOC_MAGIC, 6, struct jtag_cmd)
|
||||
|
||||
/* Generates arg pulses on TCLK pin */
|
||||
#define JTAG_CLK _IOW(JTAG_IOC_MAGIC, 7, unsigned int *)
|
||||
|
||||
#define JTAG_IOC_MAXNR 9
|
||||
|
||||
#endif /* __JTAG_H__ */
|
||||
Loading…
Reference in New Issue