From 97d2ed102eb1e896ac5d671dd2de8b35fcc8e5a9 Mon Sep 17 00:00:00 2001 From: Werner Almesberger Date: Thu, 19 Aug 2010 09:03:34 -0300 Subject: [PATCH] fw/boot/boot.c (boot_loader): removed description of IDBG-specific power sensing. --- fw/boot/boot.c | 24 ------------------------ 1 file changed, 24 deletions(-) diff --git a/fw/boot/boot.c b/fw/boot/boot.c index cf7e80f..eb7aec2 100644 --- a/fw/boot/boot.c +++ b/fw/boot/boot.c @@ -186,30 +186,6 @@ static void boot_loader(void) printk("%s #%u\n", build_date, build_number); - /* - * Very weakly pull SDA down and disable all pull-ups. - * - * We use SDA as a system power presence detector. When I2C is idle, - * SDA is kept high. This is accomplished with pull-ups in the system. - * We can therefore detect if IO_3V3 is any good by checking whether - * SDA is high. - * - * This should work even without our own pull-down. However, when the - * IDBG board is operating standalone (or, generally, if SDA isn't - * connected), SDA would float. We therefore have to pull it down a - * little. - */ - - /* - * Ben variant: - * - * We use exactly the same logic as on GTA01/02, but with different - * signals. P0_1 (I2C_SDA_PULL) and P0_2 (I2C_SDA) both connect to - * +V3.3, with a 1 kOhm resistor on P0_1. If the Ben is not powered, we - * can therefore pull +V3.3 to GND, and detect this condition. As on - * the GTA01/02, once the system is powered up, IDBG exits this loop. - */ - PLATFORM_SETUP; dfu_init();