1 files changed, 409 insertions, 0 deletions

diff --git a/drivers/i2c/busses/i2c-parport.c b/drivers/i2c/busses/i2c-parport.c
new file mode 100644
index 000000000..0af86a542
--- /dev/null
+++ b/drivers/i2c/busses/i2c-parport.c
@@ -0,0 +1,409 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* ------------------------------------------------------------------------ *
+ * i2c-parport.c I2C bus over parallel port                                 *
+ * ------------------------------------------------------------------------ *
+   Copyright (C) 2003-2011 Jean Delvare <jdelvare@suse.de>
+
+   Based on older i2c-philips-par.c driver
+   Copyright (C) 1995-2000 Simon G. Vogl
+   With some changes from:
+   Frodo Looijaard <frodol@dds.nl>
+   Kyösti Mälkki <kmalkki@cc.hut.fi>
+
+ * ------------------------------------------------------------------------ */
+
+#define pr_fmt(fmt) "i2c-parport: " fmt
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/parport.h>
+#include <linux/i2c.h>
+#include <linux/i2c-algo-bit.h>
+#include <linux/i2c-smbus.h>
+#include <linux/slab.h>
+#include <linux/list.h>
+#include <linux/mutex.h>
+
+#define PORT_DATA	0
+#define PORT_STAT	1
+#define PORT_CTRL	2
+
+struct lineop {
+	u8 val;
+	u8 port;
+	u8 inverted;
+};
+
+struct adapter_parm {
+	struct lineop setsda;
+	struct lineop setscl;
+	struct lineop getsda;
+	struct lineop getscl;
+	struct lineop init;
+	unsigned int smbus_alert:1;
+};
+
+static const struct adapter_parm adapter_parm[] = {
+	/* type 0: Philips adapter */
+	{
+		.setsda	= { 0x80, PORT_DATA, 1 },
+		.setscl	= { 0x08, PORT_CTRL, 0 },
+		.getsda	= { 0x80, PORT_STAT, 0 },
+		.getscl	= { 0x08, PORT_STAT, 0 },
+	},
+	/* type 1: home brew teletext adapter */
+	{
+		.setsda	= { 0x02, PORT_DATA, 0 },
+		.setscl	= { 0x01, PORT_DATA, 0 },
+		.getsda	= { 0x80, PORT_STAT, 1 },
+	},
+	/* type 2: Velleman K8000 adapter */
+	{
+		.setsda	= { 0x02, PORT_CTRL, 1 },
+		.setscl	= { 0x08, PORT_CTRL, 1 },
+		.getsda	= { 0x10, PORT_STAT, 0 },
+	},
+	/* type 3: ELV adapter */
+	{
+		.setsda	= { 0x02, PORT_DATA, 1 },
+		.setscl	= { 0x01, PORT_DATA, 1 },
+		.getsda	= { 0x40, PORT_STAT, 1 },
+		.getscl	= { 0x08, PORT_STAT, 1 },
+	},
+	/* type 4: ADM1032 evaluation board */
+	{
+		.setsda	= { 0x02, PORT_DATA, 1 },
+		.setscl	= { 0x01, PORT_DATA, 1 },
+		.getsda	= { 0x10, PORT_STAT, 1 },
+		.init	= { 0xf0, PORT_DATA, 0 },
+		.smbus_alert = 1,
+	},
+	/* type 5: ADM1025, ADM1030 and ADM1031 evaluation boards */
+	{
+		.setsda	= { 0x02, PORT_DATA, 1 },
+		.setscl	= { 0x01, PORT_DATA, 1 },
+		.getsda	= { 0x10, PORT_STAT, 1 },
+	},
+	/* type 6: Barco LPT->DVI (K5800236) adapter */
+	{
+		.setsda	= { 0x02, PORT_DATA, 1 },
+		.setscl	= { 0x01, PORT_DATA, 1 },
+		.getsda	= { 0x20, PORT_STAT, 0 },
+		.getscl	= { 0x40, PORT_STAT, 0 },
+		.init	= { 0xfc, PORT_DATA, 0 },
+	},
+	/* type 7: One For All JP1 parallel port adapter */
+	{
+		.setsda	= { 0x01, PORT_DATA, 0 },
+		.setscl	= { 0x02, PORT_DATA, 0 },
+		.getsda	= { 0x80, PORT_STAT, 1 },
+		.init	= { 0x04, PORT_DATA, 1 },
+	},
+	/* type 8: VCT-jig */
+	{
+		.setsda	= { 0x04, PORT_DATA, 1 },
+		.setscl	= { 0x01, PORT_DATA, 1 },
+		.getsda	= { 0x40, PORT_STAT, 0 },
+		.getscl	= { 0x80, PORT_STAT, 1 },
+	},
+};
+
+/* ----- Device list ------------------------------------------------------ */
+
+struct i2c_par {
+	struct pardevice *pdev;
+	struct i2c_adapter adapter;
+	struct i2c_algo_bit_data algo_data;
+	struct i2c_smbus_alert_setup alert_data;
+	struct i2c_client *ara;
+	struct list_head node;
+};
+
+static LIST_HEAD(adapter_list);
+static DEFINE_MUTEX(adapter_list_lock);
+
+#define MAX_DEVICE 4
+static int parport[MAX_DEVICE] = {0, -1, -1, -1};
+module_param_array(parport, int, NULL, 0);
+MODULE_PARM_DESC(parport,
+		 "List of parallel ports to bind to, by index.\n"
+		 " At most " __stringify(MAX_DEVICE) " devices are supported.\n"
+		 " Default is one device connected to parport0.\n"
+);
+
+static int type = -1;
+module_param(type, int, 0);
+MODULE_PARM_DESC(type,
+	"Type of adapter:\n"
+	" 0 = Philips adapter\n"
+	" 1 = home brew teletext adapter\n"
+	" 2 = Velleman K8000 adapter\n"
+	" 3 = ELV adapter\n"
+	" 4 = ADM1032 evaluation board\n"
+	" 5 = ADM1025, ADM1030 and ADM1031 evaluation boards\n"
+	" 6 = Barco LPT->DVI (K5800236) adapter\n"
+	" 7 = One For All JP1 parallel port adapter\n"
+	" 8 = VCT-jig\n"
+);
+
+/* ----- Low-level parallel port access ----------------------------------- */
+
+static void port_write_data(struct parport *p, unsigned char d)
+{
+	parport_write_data(p, d);
+}
+
+static void port_write_control(struct parport *p, unsigned char d)
+{
+	parport_write_control(p, d);
+}
+
+static unsigned char port_read_data(struct parport *p)
+{
+	return parport_read_data(p);
+}
+
+static unsigned char port_read_status(struct parport *p)
+{
+	return parport_read_status(p);
+}
+
+static unsigned char port_read_control(struct parport *p)
+{
+	return parport_read_control(p);
+}
+
+static void (* const port_write[])(struct parport *, unsigned char) = {
+	port_write_data,
+	NULL,
+	port_write_control,
+};
+
+static unsigned char (* const port_read[])(struct parport *) = {
+	port_read_data,
+	port_read_status,
+	port_read_control,
+};
+
+/* ----- Unified line operation functions --------------------------------- */
+
+static inline void line_set(struct parport *data, int state,
+	const struct lineop *op)
+{
+	u8 oldval = port_read[op->port](data);
+
+	/* Touch only the bit(s) needed */
+	if ((op->inverted && !state) || (!op->inverted && state))
+		port_write[op->port](data, oldval | op->val);
+	else
+		port_write[op->port](data, oldval & ~op->val);
+}
+
+static inline int line_get(struct parport *data,
+	const struct lineop *op)
+{
+	u8 oldval = port_read[op->port](data);
+
+	return ((op->inverted && (oldval & op->val) != op->val)
+	    || (!op->inverted && (oldval & op->val) == op->val));
+}
+
+/* ----- I2C algorithm call-back functions and structures ----------------- */
+
+static void parport_setscl(void *data, int state)
+{
+	line_set((struct parport *) data, state, &adapter_parm[type].setscl);
+}
+
+static void parport_setsda(void *data, int state)
+{
+	line_set((struct parport *) data, state, &adapter_parm[type].setsda);
+}
+
+static int parport_getscl(void *data)
+{
+	return line_get((struct parport *) data, &adapter_parm[type].getscl);
+}
+
+static int parport_getsda(void *data)
+{
+	return line_get((struct parport *) data, &adapter_parm[type].getsda);
+}
+
+/* Encapsulate the functions above in the correct structure.
+   Note that this is only a template, from which the real structures are
+   copied. The attaching code will set getscl to NULL for adapters that
+   cannot read SCL back, and will also make the data field point to
+   the parallel port structure. */
+static const struct i2c_algo_bit_data parport_algo_data = {
+	.setsda		= parport_setsda,
+	.setscl		= parport_setscl,
+	.getsda		= parport_getsda,
+	.getscl		= parport_getscl,
+	.udelay		= 10, /* ~50 kbps */
+	.timeout	= HZ,
+};
+
+/* ----- I2c and parallel port call-back functions and structures --------- */
+
+static void i2c_parport_irq(void *data)
+{
+	struct i2c_par *adapter = data;
+	struct i2c_client *ara = adapter->ara;
+
+	if (ara) {
+		dev_dbg(&ara->dev, "SMBus alert received\n");
+		i2c_handle_smbus_alert(ara);
+	} else
+		dev_dbg(&adapter->adapter.dev,
+			"SMBus alert received but no ARA client!\n");
+}
+
+static void i2c_parport_attach(struct parport *port)
+{
+	struct i2c_par *adapter;
+	int i;
+	struct pardev_cb i2c_parport_cb;
+
+	if (type < 0) {
+		pr_warn("adapter type unspecified\n");
+		return;
+	}
+
+	if (type >= ARRAY_SIZE(adapter_parm)) {
+		pr_warn("invalid type (%d)\n", type);
+		return;
+	}
+
+	for (i = 0; i < MAX_DEVICE; i++) {
+		if (parport[i] == -1)
+			continue;
+		if (port->number == parport[i])
+			break;
+	}
+	if (i == MAX_DEVICE) {
+		pr_debug("Not using parport%d.\n", port->number);
+		return;
+	}
+
+	adapter = kzalloc(sizeof(struct i2c_par), GFP_KERNEL);
+	if (!adapter)
+		return;
+	memset(&i2c_parport_cb, 0, sizeof(i2c_parport_cb));
+	i2c_parport_cb.flags = PARPORT_FLAG_EXCL;
+	i2c_parport_cb.irq_func = i2c_parport_irq;
+	i2c_parport_cb.private = adapter;
+
+	pr_debug("attaching to %s\n", port->name);
+	parport_disable_irq(port);
+	adapter->pdev = parport_register_dev_model(port, "i2c-parport",
+						   &i2c_parport_cb, i);
+	if (!adapter->pdev) {
+		pr_err("Unable to register with parport\n");
+		goto err_free;
+	}
+
+	/* Fill the rest of the structure */
+	adapter->adapter.owner = THIS_MODULE;
+	adapter->adapter.class = I2C_CLASS_HWMON;
+	strscpy(adapter->adapter.name, "Parallel port adapter",
+		sizeof(adapter->adapter.name));
+	adapter->algo_data = parport_algo_data;
+	/* Slow down if we can't sense SCL */
+	if (!adapter_parm[type].getscl.val) {
+		adapter->algo_data.getscl = NULL;
+		adapter->algo_data.udelay = 50; /* ~10 kbps */
+	}
+	adapter->algo_data.data = port;
+	adapter->adapter.algo_data = &adapter->algo_data;
+	adapter->adapter.dev.parent = port->physport->dev;
+
+	if (parport_claim_or_block(adapter->pdev) < 0) {
+		dev_err(&adapter->pdev->dev,
+			"Could not claim parallel port\n");
+		goto err_unregister;
+	}
+
+	/* Reset hardware to a sane state (SCL and SDA high) */
+	parport_setsda(port, 1);
+	parport_setscl(port, 1);
+	/* Other init if needed (power on...) */
+	if (adapter_parm[type].init.val) {
+		line_set(port, 1, &adapter_parm[type].init);
+		/* Give powered devices some time to settle */
+		msleep(100);
+	}
+
+	if (i2c_bit_add_bus(&adapter->adapter) < 0) {
+		dev_err(&adapter->pdev->dev, "Unable to register with I2C\n");
+		goto err_unregister;
+	}
+
+	/* Setup SMBus alert if supported */
+	if (adapter_parm[type].smbus_alert) {
+		struct i2c_client *ara;
+
+		ara = i2c_new_smbus_alert_device(&adapter->adapter,
+						 &adapter->alert_data);
+		if (!IS_ERR(ara)) {
+			adapter->ara = ara;
+			parport_enable_irq(port);
+		} else {
+			dev_warn(&adapter->pdev->dev,
+				 "Failed to register ARA client\n");
+		}
+	}
+
+	/* Add the new adapter to the list */
+	mutex_lock(&adapter_list_lock);
+	list_add_tail(&adapter->node, &adapter_list);
+	mutex_unlock(&adapter_list_lock);
+	return;
+
+ err_unregister:
+	parport_release(adapter->pdev);
+	parport_unregister_device(adapter->pdev);
+ err_free:
+	kfree(adapter);
+}
+
+static void i2c_parport_detach(struct parport *port)
+{
+	struct i2c_par *adapter, *_n;
+
+	/* Walk the list */
+	mutex_lock(&adapter_list_lock);
+	list_for_each_entry_safe(adapter, _n, &adapter_list, node) {
+		if (adapter->pdev->port == port) {
+			if (adapter->ara) {
+				parport_disable_irq(port);
+				i2c_unregister_device(adapter->ara);
+			}
+			i2c_del_adapter(&adapter->adapter);
+
+			/* Un-init if needed (power off...) */
+			if (adapter_parm[type].init.val)
+				line_set(port, 0, &adapter_parm[type].init);
+
+			parport_release(adapter->pdev);
+			parport_unregister_device(adapter->pdev);
+			list_del(&adapter->node);
+			kfree(adapter);
+		}
+	}
+	mutex_unlock(&adapter_list_lock);
+}
+
+static struct parport_driver i2c_parport_driver = {
+	.name = "i2c-parport",
+	.match_port = i2c_parport_attach,
+	.detach = i2c_parport_detach,
+	.devmodel = true,
+};
+module_parport_driver(i2c_parport_driver);
+
+MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>");
+MODULE_DESCRIPTION("I2C bus over parallel port");
+MODULE_LICENSE("GPL");