Add JTAG bitbang driver

Signed-off-by: Wjatscheslaw Stoljarski <wjatscheslaw.stoljarski@kiwigrid.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

5 files changed, 416 insertions, 0 deletions

diff --git a/drivers/Kconfig b/drivers/Kconfig
index 883b0e7bc9..e596c50fbc 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 ea3263f615..005ab247ce 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 0000000000..c3d31ec9a2
--- /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 0000000000..b0855777a9
--- /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 0000000000..99fd081b31
--- /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@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");