RE: [PATCH v3 10/11] OMAP3: PM: Program correct init voltages for VDD1 and VDD2

From: "Gopinath, Thara" <thara@ti.com>
To: Kevin Hilman <khilman@deeprootsystems.com>
Cc: "linux-omap@vger.kernel.org" <linux-omap@vger.kernel.org>,
	"paul@pwsan.com" <paul@pwsan.com>,
	"Cousson, Benoit" <b-cousson@ti.com>,
	"Sripathy, Vishwanath" <vishwanath.bs@ti.com>,
	"Sawant, Anand" <sawant@ti.com>
Subject: RE: [PATCH v3 10/11] OMAP3: PM: Program correct init voltages for VDD1 and VDD2
Date: Fri, 22 Oct 2010 20:14:51 +0530	[thread overview]
Message-ID: <5A47E75E594F054BAF48C5E4FC4B92AB035EB95EAD@dbde02.ent.ti.com> (raw)
In-Reply-To: <871v7spc07.fsf@deeprootsystems.com>


>>-----Original Message-----
>>From: Kevin Hilman [mailto:khilman@deeprootsystems.com]
>>Sent: Friday, October 15, 2010 5:23 AM
>>To: Gopinath, Thara
>>Cc: linux-omap@vger.kernel.org; paul@pwsan.com; Cousson, Benoit; Sripathy,
>>Vishwanath; Sawant, Anand
>>Subject: Re: [PATCH v3 10/11] OMAP3: PM: Program correct init voltages for
>>VDD1 and VDD2
>>
>>Thara Gopinath <thara@ti.com> writes:
>>
>>> By default the system boots up at nominal voltage for every
>>> voltage domain in the system. This patch puts VDD1 and VDD2
>>> to the correct boot up voltage as per the opp tables specified.
>>> This patch implements this by matching the rate of the main clock
>>> of the voltage domain with the opp table and picking up the correct
>>> voltage.
>>>
>>> Signed-off-by: Thara Gopinath <thara@ti.com>
>>
>>For de-coupling the init from OPP, I like this approach better.  Thanks.
Most welcome!!
>>
>>Minor comment below...
>>
>>> ---
>>>  arch/arm/mach-omap2/pm.c |   67
>>+++++++++++++++++++++++++++++++++++++++++++++-
>>>  1 files changed, 66 insertions(+), 1 deletions(-)
>>>
>>> diff --git a/arch/arm/mach-omap2/pm.c b/arch/arm/mach-omap2/pm.c
>>> index 71c5a77..86c7bf1 100644
>>> --- a/arch/arm/mach-omap2/pm.c
>>> +++ b/arch/arm/mach-omap2/pm.c
>>> @@ -13,6 +13,7 @@
>>>  #include <linux/init.h>
>>>  #include <linux/io.h>
>>>  #include <linux/err.h>
>>> +#include <linux/clk.h>
>>>
>>>  #include <plat/omap-pm.h>
>>>  #include <plat/omap_device.h>
>>> @@ -20,6 +21,7 @@
>>>
>>>  #include <plat/powerdomain.h>
>>>  #include <plat/clockdomain.h>
>>> +#include <plat/voltage.h>
>>>
>>>  #include "pm.h"
>>>
>>> @@ -138,12 +140,75 @@ err:
>>>  	return ret;
>>>  }
>>>
>>> +/*
>>> + * This is to be called during init to put the various voltage
>>> + * domains to the voltage as per the opp table. Typically we boot up
>>> + * at the nominal voltage. So this function finds out the rate of
>>> + * the clock associated with the voltage domain, finds out the correct
>>> + * opp entry and puts the voltage domain to the voltage specifies
>>> + * in the opp entry
>>> + */
>>> +static int __init omap2_set_init_voltage(char *vdd_name, char *clk_name,
>>> +						struct device *dev)
>>> +{
>>> +	struct voltagedomain *voltdm;
>>> +	struct clk *_clk;
>>
>>s/_clk/clk/
Will it not conflict with struct clk??

Regards
Thara

>>
>>> +	struct omap_opp *opp;
>>> +	unsigned long freq, bootup_volt;
>>> +
>>> +	if (!vdd_name || !clk_name || !dev) {
>>> +		printk(KERN_ERR "%s: Invalid parameters!\n", __func__);
>>> +		goto exit;
>>> +	}
>>> +
>>> +	voltdm = omap_voltage_domain_get(vdd_name);
>>> +	if (IS_ERR(voltdm)) {
>>> +		printk(KERN_ERR "%s: Unable to get vdd pointer for vdd_%s\n",
>>> +			__func__, vdd_name);
>>> +		goto exit;
>>> +	}
>>> +
>>> +	_clk =  clk_get(NULL, clk_name);
>>> +	if (IS_ERR(_clk)) {
>>> +		printk(KERN_ERR "%s: unable to get clk %s\n",
>>> +			__func__, clk_name);
>>> +		goto exit;
>>> +	}
>>> +
>>> +	freq = _clk->rate;
>>> +	opp = opp_find_freq_ceil(dev, &freq);
>>> +	if (IS_ERR(opp)) {
>>> +		printk(KERN_ERR "%s: unable to find boot up OPP for vdd_%s\n",
>>> +			__func__, vdd_name);
>>> +		goto exit;
>>> +	}
>>> +
>>> +	bootup_volt = opp_get_voltage(opp);
>>> +	if (!bootup_volt) {
>>> +		printk(KERN_ERR "%s: unable to find voltage corresponding"
>>> +			"to the bootup OPP for vdd_%s\n", __func__, vdd_name);
>>> +		goto exit;
>>> +	}
>>> +
>>> +	omap_voltage_scale_vdd(voltdm, bootup_volt);
>>> +
>>> +	return 0;
>>> +
>>> +exit:
>>> +	printk(KERN_ERR "%s: Unable to put vdd_%s to its init voltage\n\n",
>>> +		__func__, vdd_name);
>>> +	return -EINVAL;
>>> +}
>>> +
>>>  static int __init omap2_common_pm_init(void)
>>>  {
>>>  	omap2_init_processor_devices();
>>>
>>> -	if (cpu_is_omap34xx())
>>> +	if (cpu_is_omap34xx()) {
>>>  		omap3_pm_init_opp_table();
>>> +		omap2_set_init_voltage("mpu", "dpll1_ck", mpu_dev);
>>> +		omap2_set_init_voltage("core", "l3_ick", l3_dev);
>>> +	}
>>>
>>>  	omap_pm_if_init();