[PATCH 3/6] i2c-parport: define ports to connect

From: Sudip Mukherjee
Date: Wed May 20 2015 - 11:29:50 EST


As of now i2c-parport was connecting to all the available parallel
ports. Lets limit that to maximum of 4 instances and at the same time
define which instance connects to which parallel port.

Tested-by: Jean Delvare <jdelvare@xxxxxxx>
Signed-off-by: Sudip Mukherjee <sudip@xxxxxxxxxxxxxxx>
---

MODULE_PARM_DESC modified

drivers/i2c/busses/i2c-parport.c | 23 +++++++++++++++++++++++
1 file changed, 23 insertions(+)

diff --git a/drivers/i2c/busses/i2c-parport.c b/drivers/i2c/busses/i2c-parport.c
index a1fac5a..155da95 100644
--- a/drivers/i2c/busses/i2c-parport.c
+++ b/drivers/i2c/busses/i2c-parport.c
@@ -46,6 +46,9 @@ struct i2c_par {

static LIST_HEAD(adapter_list);
static DEFINE_MUTEX(adapter_list_lock);
+#define MAX_DEVICE 4
+static int parport[MAX_DEVICE] = {0, -1, -1, -1};
+

/* ----- Low-level parallel port access ----------------------------------- */

@@ -163,6 +166,19 @@ static void i2c_parport_irq(void *data)
static void i2c_parport_attach(struct parport *port)
{
struct i2c_par *adapter;
+ int i;
+ struct pardev_cb i2c_parport_cb;
+
+ for (i = 0; i < MAX_DEVICE; i++) {
+ if (parport[i] == -1)
+ continue;
+ if (port->number == parport[i])
+ break;
+ }
+ if (i == MAX_DEVICE) {
+ pr_debug("i2c-parport: Not using parport%d.\n", port->number);
+ return;
+ }

adapter = kzalloc(sizeof(struct i2c_par), GFP_KERNEL);
if (adapter == NULL) {
@@ -298,5 +314,12 @@ MODULE_AUTHOR("Jean Delvare <jdelvare@xxxxxxx>");
MODULE_DESCRIPTION("I2C bus over parallel port");
MODULE_LICENSE("GPL");

+module_param_array(parport, int, NULL, 0);
+MODULE_PARM_DESC(parport,
+ "List of parallel ports to bind to, by index.\n"
+ " Atmost " __stringify(MAX_DEVICE) " devices are supported.\n"
+ " Default is one device connected to parport0.\n"
+);
+
module_init(i2c_parport_init);
module_exit(i2c_parport_exit);
--
1.8.1.2

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