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barebox/drivers/misc/jtag.c

393 lines
9.8 KiB
C

/*
* drivers/misc/jtag.c - More infos in include/jtag.h
*
* Written Aug 2009 by Davide Rizzo <elpa.rizzo@gmail.com>
*
* Ported to barebox Jul 2012 by
* Wjatscheslaw Stoljarski <wjatscheslaw.stoljarski@kiwigrid.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.
*/
#include <fs.h>
#include <errno.h>
//#include <linux/list.h>
#include <jtag.h>
#include <gpio.h>
#include <driver.h>
#include <malloc.h>
#include <common.h>
#include <init.h>
#include <ioctl.h>
#define VERSION_MAJ 1
#define VERSION_MIN 0
/* Max devices in the jtag chain */
#define MAX_DEVICES 16
struct jtag_info {
struct jtag_platdata *pdata;
struct cdev cdev;
unsigned int devices; /* Number of devices found in the jtag chain */
/* Instruction register length of every device in the chain */
unsigned int ir_len[MAX_DEVICES]; /* [devices] */
};
static const unsigned long bypass = 0xFFFFFFFF;
static void pulse_tms0(const struct jtag_platdata *pdata)
{
gpio_set_value(pdata->gpio_tms, 0);
gpio_set_value(pdata->gpio_tclk, 0);
gpio_set_value(pdata->gpio_tclk, 1);
}
static void pulse_tms1(const struct jtag_platdata *pdata)
{
gpio_set_value(pdata->gpio_tms, 1);
gpio_set_value(pdata->gpio_tclk, 0);
gpio_set_value(pdata->gpio_tclk, 1);
}
static void jtag_reset(const struct jtag_platdata *pdata)
{
gpio_set_value(pdata->gpio_tms, 1);
gpio_set_value(pdata->gpio_tclk, 0);
gpio_set_value(pdata->gpio_tclk, 1);
gpio_set_value(pdata->gpio_tclk, 0);
gpio_set_value(pdata->gpio_tclk, 1);
gpio_set_value(pdata->gpio_tclk, 0);
gpio_set_value(pdata->gpio_tclk, 1);
gpio_set_value(pdata->gpio_tclk, 0);
gpio_set_value(pdata->gpio_tclk, 1);
gpio_set_value(pdata->gpio_tclk, 0);
gpio_set_value(pdata->gpio_tclk, 1);
}
static void jtag_output(const struct jtag_platdata *pdata,
const unsigned long *data, unsigned int bitlen, int notlast)
{
unsigned int a;
unsigned long mask;
gpio_set_value(pdata->gpio_tms, 0);
while (bitlen > 0) {
for (a = *data++, mask = 0x00000001; mask != 0 && bitlen > 0;
mask <<= 1, bitlen--) {
gpio_set_value(pdata->gpio_tdo, (a & mask) ? 1 : 0);
if ((bitlen == 1) && !notlast)
gpio_set_value(pdata->gpio_tms, 1);
gpio_set_value(pdata->gpio_tclk, 0);
gpio_set_value(pdata->gpio_tclk, 1);
}
}
}
static int jtag_ioctl(struct cdev *inode, int cmd, void *arg)
{
int ret = 0;
struct jtag_info *info = (struct jtag_info *)inode->priv;
int devices = info->devices;
struct jtag_cmd *jcmd = (struct jtag_cmd *)arg;
struct jtag_platdata *pdata = info->pdata;
if (_IOC_TYPE(cmd) != JTAG_IOC_MAGIC) return -ENOTTY;
if (_IOC_NR(cmd) > JTAG_IOC_MAXNR) return -ENOTTY;
switch (cmd) {
case JTAG_GET_DEVICES:
/* Returns how many devices found in the chain */
ret = info->devices;
break;
case JTAG_GET_ID:
/* Returns ID register of selected device */
if ((((struct jtag_rd_id *)arg)->device < 0) ||
(((struct jtag_rd_id *)arg)->device >= devices)) {
ret = -EINVAL;
break;
}
jtag_reset(pdata);
pulse_tms0(pdata);
pulse_tms1(pdata);
pulse_tms0(pdata);
pulse_tms0(pdata);
while (devices-- > 0) {
unsigned long id = 0;
pulse_tms0(pdata);
if (gpio_get_value(pdata->gpio_tdi)) {
unsigned long mask;
for (id = 1, mask = 0x00000002; (mask != 0);
mask <<= 1) {
pulse_tms0(pdata);
if (gpio_get_value(pdata->gpio_tdi))
id |= mask;
}
}
if (devices == ((struct jtag_rd_id *)arg)->device) {
((struct jtag_rd_id *)arg)->id = id;
ret = 0;
break;
}
}
jtag_reset(pdata);
break;
case JTAG_SET_IR_LENGTH:
/* Sets up IR length of one device */
if ((jcmd->device >= 0) && (jcmd->device < devices))
info->ir_len[jcmd->device] = jcmd->bitlen;
else
ret = -EINVAL;
break;
case JTAG_RESET:
/* Resets all JTAG states */
jtag_reset(pdata);
break;
case JTAG_IR_WR:
/*
* Writes Instruction Register
* If device == -1 writes same Instruction Register in
* all devices.
* If device >= 0 writes Instruction Register in selected
* device and loads BYPASS instruction in all others.
*/
if ((jcmd->device < -1) || (jcmd->device >= devices)) {
ret = -EINVAL;
break;
}
pulse_tms0(pdata);
pulse_tms1(pdata);
pulse_tms1(pdata);
pulse_tms0(pdata);
pulse_tms0(pdata);
while (devices-- > 0) {
if ((jcmd->device == -1) || (jcmd->device == devices))
/* Loads desired instruction */
jtag_output(pdata, jcmd->data,
info->ir_len[devices], devices);
else
/* Loads BYPASS instruction */
jtag_output(pdata, &bypass,
info->ir_len[devices], devices);
}
pulse_tms1(pdata);
pulse_tms0(pdata);
break;
case JTAG_DR_WR:
/*
* Writes Data Register of all devices
* If device == -1 writes same Data Register in all devices.
* If device >= 0 writes Data Register in selected device
* and loads BYPASS instruction in all others.
*/
if ((jcmd->device < -1) || (jcmd->device >= devices)) {
ret = -EINVAL;
break;
}
pulse_tms0(pdata);
pulse_tms1(pdata);
pulse_tms0(pdata);
pulse_tms0(pdata);
while (devices-- > 0) {
if ((jcmd->device == -1) || (devices == jcmd->device))
/* Loads desired data */
jtag_output(pdata, jcmd->data, jcmd->bitlen,
devices);
else
/* Loads 1 dummy bit in BYPASS data register */
jtag_output(pdata, &bypass, 1, devices);
}
pulse_tms1(pdata);
pulse_tms0(pdata);
break;
case JTAG_DR_RD:
/* Reads data register of selected device */
if ((jcmd->device < 0) || (jcmd->device >= devices))
ret = -EINVAL;
else {
unsigned long mask;
int bitlen = jcmd->bitlen;
unsigned long *data = jcmd->data;
pulse_tms0(pdata);
pulse_tms1(pdata);
pulse_tms0(pdata);
pulse_tms0(pdata);
devices -= (jcmd->device + 1);
while (devices-- > 0)
pulse_tms0(pdata);
while (bitlen > 0) {
for (*data = 0, mask = 0x00000001;
(mask != 0) && (bitlen > 0);
mask <<= 1, bitlen--) {
if (bitlen == 1)
pulse_tms1(pdata);
else
pulse_tms0(pdata);
if (gpio_get_value(pdata->gpio_tdi))
*data |= mask;
}
data++;
}
pulse_tms1(pdata);
pulse_tms0(pdata);
}
break;
case JTAG_CLK:
/* Generates arg clock pulses */
gpio_set_value(pdata->gpio_tms, 0);
while ((*(unsigned int *) arg)--) {
gpio_set_value(pdata->gpio_tclk, 0);
gpio_set_value(pdata->gpio_tclk, 1);
}
break;
default:
ret = -EFAULT;
}
return ret;
}
static struct file_operations jtag_operations = {
.ioctl = jtag_ioctl,
};
static int jtag_probe(struct device_d *pdev)
{
int i, ret;
struct jtag_info *info;
struct jtag_platdata *pdata = pdev->platform_data;
/* Setup gpio pins */
gpio_direction_output(pdata->gpio_tms, 0);
gpio_direction_output(pdata->gpio_tclk, 1);
gpio_direction_output(pdata->gpio_tdo, 0);
gpio_direction_input(pdata->gpio_tdi);
if (pdata->use_gpio_trst) {
/*
* Keep fixed at 1 because some devices in the chain could
* not use it, to reset chain use jtag_reset()
*/
gpio_direction_output(pdata->gpio_trst, 1);
}
/* Find how many devices in chain */
jtag_reset(pdata);
pulse_tms0(pdata);
pulse_tms1(pdata);
pulse_tms1(pdata);
pulse_tms0(pdata);
pulse_tms0(pdata);
gpio_set_value(pdata->gpio_tdo, 1);
/* Fills all IR with bypass instruction */
for (i = 0; i < 32 * MAX_DEVICES; i++)
pulse_tms0(pdata);
pulse_tms1(pdata);
pulse_tms1(pdata);
pulse_tms1(pdata);
pulse_tms0(pdata);
pulse_tms0(pdata);
gpio_set_value(pdata->gpio_tdo, 0);
/* Fills all 1-bit bypass register with 0 */
for (i = 0; i < MAX_DEVICES + 2; i++)
pulse_tms0(pdata);
gpio_set_value(pdata->gpio_tdo, 1);
/* Counts chain's bit length */
for (i = 0; i < MAX_DEVICES + 1; i++) {
pulse_tms0(pdata);
if (gpio_get_value(pdata->gpio_tdi))
break;
}
dev_notice(pdev, "%d devices found in chain\n", i);
/* Allocate structure with chain specific infos */
info = xzalloc(sizeof(struct jtag_info) + sizeof(info->ir_len[0]) * i);
info->devices = i;
info->pdata = pdata;
pdev->priv = info;
info->cdev.name = JTAG_NAME;
info->cdev.dev = pdev;
info->cdev.ops = &jtag_operations;
info->cdev.priv = info;
ret = devfs_create(&info->cdev);
if (ret)
goto fail_devfs_create;
return 0;
fail_devfs_create:
pdev->priv = NULL;
free(info);
return ret;
}
static void jtag_info(struct device_d *pdev)
{
int dn, ret;
struct jtag_rd_id jid;
struct jtag_info *info = pdev->priv;
printf(" JTAG:\n");
printf(" Devices found: %d\n", info->devices);
for (dn = 0; dn < info->devices; dn++) {
jid.device = dn;
ret = jtag_ioctl(&info->cdev, JTAG_GET_ID, &jid);
printf(" Device number: %d\n", dn);
if (ret == -1)
printf(" JTAG_GET_ID failed: %s\n", strerror(errno));
else
printf(" ID: 0x%lX\n", jid.id);
}
}
static void jtag_remove(struct device_d *pdev)
{
struct jtag_info *info = (struct jtag_info *) pdev->priv;
devfs_remove(&info->cdev);
pdev->priv = NULL;
free(info);
dev_notice(pdev, "Device removed\n");
}
static struct driver_d jtag_driver = {
.name = JTAG_NAME,
.probe = jtag_probe,
.remove = jtag_remove,
.info = jtag_info,
};
static int jtag_module_init(void)
{
return register_driver(&jtag_driver);
}
device_initcall(jtag_module_init);
MODULE_AUTHOR("Davide Rizzo <elpa.rizzo@gmail.com>");
MODULE_AUTHOR("Wjatscheslaw Stoljarski <wjatscheslaw.stoljarski@kiwigrid.com>");
MODULE_DESCRIPTION("JTAG bitbang driver");
MODULE_LICENSE("GPL");