[PATCH v2] Add JTAG bitbang driver
Sascha Hauer
s.hauer at pengutronix.de
Mon Aug 13 15:42:59 EDT 2012
Hi Wjatscheslaw,
Sorry for the delay. I was not sure whether I should apply this patch
or just keep it here for reference. The problem is that it's not very
useful without some code actually using this driver. I decided to apply
it, because the 'devinfo' information makes it kind of self contained.
Thanks for the patch
Sascha
On Thu, Aug 09, 2012 at 02:44:49PM +0200, Wjatscheslaw Stoljarski wrote:
> From: "Wjatscheslaw Stoljarski" <wjatscheslaw.stoljarski at kiwigrid.com>
>
> Signed-off-by: Wjatscheslaw Stoljarski <wjatscheslaw.stoljarski at kiwigrid.com>
> ---
> drivers/Kconfig | 1 +
> drivers/Makefile | 1 +
> drivers/misc/Kconfig | 17 +++
> drivers/misc/Makefile | 5 +
> drivers/misc/jtag.c | 392 +++++++++++++++++++++++++++++++++++++++++++++++++
> include/jtag.h | 109 ++++++++++++++
> 6 files changed, 525 insertions(+)
> create mode 100644 drivers/misc/Kconfig
> create mode 100644 drivers/misc/Makefile
> create mode 100644 drivers/misc/jtag.c
> create mode 100644 include/jtag.h
>
> diff --git a/drivers/Kconfig b/drivers/Kconfig
> index 883b0e7..e596c50 100644
> --- a/drivers/Kconfig
> +++ b/drivers/Kconfig
> @@ -12,6 +12,7 @@ source "drivers/video/Kconfig"
> source "drivers/mci/Kconfig"
> source "drivers/clk/Kconfig"
> source "drivers/mfd/Kconfig"
> +source "drivers/misc/Kconfig"
> source "drivers/led/Kconfig"
> source "drivers/eeprom/Kconfig"
> source "drivers/input/Kconfig"
> diff --git a/drivers/Makefile b/drivers/Makefile
> index ea3263f..005ab24 100644
> --- a/drivers/Makefile
> +++ b/drivers/Makefile
> @@ -15,5 +15,6 @@ obj-$(CONFIG_LED) += led/
> obj-y += eeprom/
> obj-$(CONFIG_PWM) += pwm/
> obj-y += input/
> +obj-y += misc/
> obj-y += dma/
> obj-y += watchdog/
> diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
> new file mode 100644
> index 0000000..c3d31ec
> --- /dev/null
> +++ b/drivers/misc/Kconfig
> @@ -0,0 +1,17 @@
> +#
> +# Misc strange devices
> +#
> +
> +menuconfig MISC_DEVICES
> + bool "Misc devices "
> + help
> + Add support for misc strange devices
> +
> +if MISC_DEVICES
> +
> +config JTAG
> + tristate "JTAG Bitbang driver"
> + help
> + Controls JTAG chains connected to I/O pins
> +
> +endif # MISC_DEVICES
> diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
> new file mode 100644
> index 0000000..b085577
> --- /dev/null
> +++ b/drivers/misc/Makefile
> @@ -0,0 +1,5 @@
> +#
> +# Makefile for misc devices that really don't fit anywhere else.
> +#
> +
> +obj-$(CONFIG_JTAG) += jtag.o
> diff --git a/drivers/misc/jtag.c b/drivers/misc/jtag.c
> new file mode 100644
> index 0000000..99fd081
> --- /dev/null
> +++ b/drivers/misc/jtag.c
> @@ -0,0 +1,392 @@
> +/*
> + * drivers/misc/jtag.c - More infos in include/jtag.h
> + *
> + * Written Aug 2009 by Davide Rizzo <elpa.rizzo at gmail.com>
> + *
> + * Ported to barebox Jul 2012 by
> + * Wjatscheslaw Stoljarski <wjatscheslaw.stoljarski at 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 at gmail.com>");
> +MODULE_AUTHOR("Wjatscheslaw Stoljarski <wjatscheslaw.stoljarski at kiwigrid.com>");
> +MODULE_DESCRIPTION("JTAG bitbang driver");
> +MODULE_LICENSE("GPL");
> diff --git a/include/jtag.h b/include/jtag.h
> new file mode 100644
> index 0000000..26c95fb
> --- /dev/null
> +++ b/include/jtag.h
> @@ -0,0 +1,109 @@
> +/*
> + * include/linux/jtag.h
> + *
> + * Written Aug 2009 by Davide Rizzo <elpa.rizzo at 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.
> + */
> +
> +/*
> + * This driver manages one or more jtag chains controlled by host pins.
> + * Jtag chains must be defined during setup using jtag_platdata structs.
> + * All operations must be done from user programs using ioctls to /dev/jtag
> + * Typical operation sequence is:
> + * - open() the device (normally /dev/jtag)
> + * - ioctl JTAG_GET_DEVICES reads how many devices in the chain
> + * (repeat for each chip in the chain)
> + * - ioctl JTAG_GET_ID identifies the chip
> + * - ioctl JTAG_SET_IR_LENGTH sets the instruction register length
> + * Before accessing the data registers, instruction registers' lenghtes
> + * 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__ */
> --
> 1.7.9.5
>
>
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