Hi, * hvaibhav@xxxxxx <hvaibhav@xxxxxx> [130304 03:40]: > From: Vaibhav Hiremath <hvaibhav@xxxxxx> > > Currently there is no clean mechanism to control debugSS module and > you have to always keep clocks enabled, either, > > - By enabling it during boot as part of clk_init function. > Or > - By having HWMOD_INIT_NO_IDLE flag in hwmod data. > > Based on the discussion, > http://www.mail-archive.com/linux-omap@xxxxxxxxxxxxxxx/msg81771.html > > This patch introduces new kernel parameter "omap_debugss_en", > which will allow user to control debugSS module enable/disable > part during boot-time. I suggest you just make this part into a standard DT only device driver. That way the command line parsing and clock enabling can happen the normal way. Is there any reason why this could not be a loadable module? Regards, Tony > Signed-off-by: Vaibhav Hiremath <hvaibhav@xxxxxx> > Cc: Kevin Hilman <khilman@xxxxxxxxxx> > Cc: Paul Walmsley <paul@xxxxxxxxx> > Cc: Tony Lindgren <tony@xxxxxxxxxxx> > --- > Tested on > - AM335x based EVM and BeagleBone platforms > > Documentation/kernel-parameters.txt | 3 + > arch/arm/mach-omap2/Makefile | 2 +- > arch/arm/mach-omap2/debugss.c | 80 +++++++++++++++++++++++++++++++++++ > 3 files changed, 84 insertions(+), 1 deletions(-) > create mode 100644 arch/arm/mach-omap2/debugss.c > > diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt > index 6c72381..bf1c822 100644 > --- a/Documentation/kernel-parameters.txt > +++ b/Documentation/kernel-parameters.txt > @@ -2051,6 +2051,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted. > For example, to override I2C bus2: > omap_mux=i2c2_scl.i2c2_scl=0x100,i2c2_sda.i2c2_sda=0x100 > > + omap_debugss_en [OMAP] Enable Debug Sub-System module required > + for JTAG debugging. > + > oprofile.timer= [HW] > Use timer interrupt instead of performance counters > > diff --git a/arch/arm/mach-omap2/Makefile b/arch/arm/mach-omap2/Makefile > index d1156cf..aaf5cc2 100644 > --- a/arch/arm/mach-omap2/Makefile > +++ b/arch/arm/mach-omap2/Makefile > @@ -5,7 +5,7 @@ > # Common support > obj-y := id.o io.o control.o mux.o devices.o fb.o serial.o gpmc.o timer.o pm.o \ > common.o gpio.o dma.o wd_timer.o display.o i2c.o hdq1w.o omap_hwmod.o \ > - omap_device.o sram.o > + omap_device.o sram.o debugss.o > > omap-2-3-common = irq.o > hwmod-common = omap_hwmod.o \ > diff --git a/arch/arm/mach-omap2/debugss.c b/arch/arm/mach-omap2/debugss.c > new file mode 100644 > index 0000000..b45bf2c > --- /dev/null > +++ b/arch/arm/mach-omap2/debugss.c > @@ -0,0 +1,80 @@ > +/* > + * debugss.c: Debug Sus-System related code goes in here > + * > + * Copyright (C) {2013} Texas Instruments Incorporated - http://www.ti.com/ > + * > + * This file is automatically generated from the AM33XX hardware databases. > + * 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 version 2. > + * > + * This program is distributed "as is" WITHOUT ANY WARRANTY of any > + * kind, whether express or implied; without even the implied warranty > + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + */ > + > +#include <linux/init.h> > +#include <linux/err.h> > +#include <linux/clk.h> > + > +#include "omap_hwmod.h" > + > +static bool is_debugss_en; > + > +/** > + * omap_debugss_en - Enable debugss clock/module based on user config > + * > + * During kernel bootup, omap2 hwmod framework will disable all the > + * unused/unclaimed modules, which in turn also disables debugss module. > + * This breaks any further debugging capability provided by HW. > + * > + * > + * Introduce early param which allows user to enable clock/module - > + * > + * omap_debugss_en (For all OMAP2 architectures) > + * > + * Please note that, with this command-line param, module always remain > + * enabled. > + */ > +static int __init omap_debugss_en(char *str) > +{ > + is_debugss_en = true; > + return 0; > +} > +early_param("omap_debugss_en", omap_debugss_en); > + > +static int __init _omap2_debugss_enable(void) > +{ > + const char oh_name[10] = "debugss"; > + struct omap_hwmod *oh; > + int ret; > + > + if (is_debugss_en) { > + struct omap_hwmod_opt_clk *oc; > + int i; > + > + oh = omap_hwmod_lookup(oh_name); > + if (!oh) { > + pr_err("debugss device not found\n"); > + return 0; > + } > + > + /* Make sure that hwmod internal data structures are setup */ > + ret = omap_hwmod_setup_one(oh_name); > + if (ret) { > + pr_err("failed to setup hwmod for %s\n", oh_name); > + return 0; > + } > + /* Enable optional clocks */ > + for (i = oh->opt_clks_cnt, oc = oh->opt_clks; i > 0; i--, oc++) { > + if (oc->_clk) > + clk_prepare_enable(oc->_clk); > + } > + /* Enable debugss clock/module */ > + omap_hwmod_enable(oh); > + } > + > + return 0; > +} > +device_initcall(_omap2_debugss_enable); > -- > 1.7.0.4 > -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
