From e97b81ddbb8b8c72b85330ac4a454a4513dcba8a Mon Sep 17 00:00:00 2001 From: "Mark M. Hoffman" Date: Thu, 23 Mar 2006 16:50:25 +0100 Subject: [PATCH] i2c-parport: Make type parameter mandatory This patch forces the user to specify what type of adapter is present when loading i2c-parport or i2c-parport-light. If none is specified, the driver init simply fails - instead of assuming adapter type 0. This alleviates the sometimes lengthy boot time delays which can be caused by accidentally building one of these into a kernel along with several i2c slave drivers that have lengthy probe routines (e.g. hwmon drivers). Kconfig and documentation updated accordingly. Signed-off-by: Mark M. Hoffman Signed-off-by: Jean Delvare Signed-off-by: Greg Kroah-Hartman --- Documentation/i2c/busses/i2c-parport | 16 ++++++++++------ drivers/i2c/busses/Kconfig | 5 ++++- drivers/i2c/busses/i2c-parport-light.c | 9 +++++++-- drivers/i2c/busses/i2c-parport.c | 9 +++++++-- drivers/i2c/busses/i2c-parport.h | 2 +- 5 files changed, 29 insertions(+), 12 deletions(-) diff --git a/Documentation/i2c/busses/i2c-parport b/Documentation/i2c/busses/i2c-parport index d9f23c0763f..77b995dfca2 100644 --- a/Documentation/i2c/busses/i2c-parport +++ b/Documentation/i2c/busses/i2c-parport @@ -12,18 +12,22 @@ meant as a replacement for the older, individual drivers: teletext adapters) It currently supports the following devices: - * Philips adapter - * home brew teletext adapter - * Velleman K8000 adapter - * ELV adapter - * Analog Devices evaluation boards (ADM1025, ADM1030, ADM1031, ADM1032) - * Barco LPT->DVI (K5800236) adapter + * (type=0) Philips adapter + * (type=1) home brew teletext adapter + * (type=2) Velleman K8000 adapter + * (type=3) ELV adapter + * (type=4) Analog Devices ADM1032 evaluation board + * (type=5) Analog Devices evaluation boards: ADM1025, ADM1030, ADM1031 + * (type=6) Barco LPT->DVI (K5800236) adapter These devices use different pinout configurations, so you have to tell the driver what you have, using the type module parameter. There is no way to autodetect the devices. Support for different pinout configurations can be easily added when needed. +Earlier kernels defaulted to type=0 (Philips). But now, if the type +parameter is missing, the driver will simply fail to initialize. + Building your own adapter ------------------------- diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index 089c6f5b24d..d6d44946a28 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -286,7 +286,10 @@ config I2C_PARPORT This driver is a replacement for (and was inspired by) an older driver named i2c-philips-par. The new driver supports more devices, and makes it easier to add support for new devices. - + + An adapter type parameter is now mandatory. Please read the file + Documentation/i2c/busses/i2c-parport for details. + Another driver exists, named i2c-parport-light, which doesn't depend on the parport driver. This is meant for embedded systems. Don't say Y here if you intend to say Y or M there. diff --git a/drivers/i2c/busses/i2c-parport-light.c b/drivers/i2c/busses/i2c-parport-light.c index c63025a4c86..e09ebbb2f9f 100644 --- a/drivers/i2c/busses/i2c-parport-light.c +++ b/drivers/i2c/busses/i2c-parport-light.c @@ -121,9 +121,14 @@ static struct i2c_adapter parport_adapter = { static int __init i2c_parport_init(void) { - if (type < 0 || type >= ARRAY_SIZE(adapter_parm)) { + if (type < 0) { + printk(KERN_WARNING "i2c-parport: adapter type unspecified\n"); + return -ENODEV; + } + + if (type >= ARRAY_SIZE(adapter_parm)) { printk(KERN_WARNING "i2c-parport: invalid type (%d)\n", type); - type = 0; + return -ENODEV; } if (base == 0) { diff --git a/drivers/i2c/busses/i2c-parport.c b/drivers/i2c/busses/i2c-parport.c index 7e2e8cd1c14..934bd55bae1 100644 --- a/drivers/i2c/busses/i2c-parport.c +++ b/drivers/i2c/busses/i2c-parport.c @@ -241,9 +241,14 @@ static struct parport_driver i2c_parport_driver = { static int __init i2c_parport_init(void) { - if (type < 0 || type >= ARRAY_SIZE(adapter_parm)) { + if (type < 0) { + printk(KERN_WARNING "i2c-parport: adapter type unspecified\n"); + return -ENODEV; + } + + if (type >= ARRAY_SIZE(adapter_parm)) { printk(KERN_WARNING "i2c-parport: invalid type (%d)\n", type); - type = 0; + return -ENODEV; } return parport_register_driver(&i2c_parport_driver); diff --git a/drivers/i2c/busses/i2c-parport.h b/drivers/i2c/busses/i2c-parport.h index d702e5e0388..9ddd816d5d0 100644 --- a/drivers/i2c/busses/i2c-parport.h +++ b/drivers/i2c/busses/i2c-parport.h @@ -90,7 +90,7 @@ static struct adapter_parm adapter_parm[] = { }, }; -static int type; +static int type = -1; module_param(type, int, 0); MODULE_PARM_DESC(type, "Type of adapter:\n" -- cgit v1.2.3