Re: [PATCH] OMAP3: PM: Scale VDD2 OPP for VDD1 OPP3 and higher

[Kevin Hilman <khilman@deeprootsystems.com>]

"Rajendra Nayak" <rnayak@ti.com> writes:

> This patch implements an implicit/internal constraint
> of 100Mhz for L3 bus while the VDD1 OPP is OPP3 or higher.
> The patch also removes the usage of bus_throughput_db
> from SRF.
> Applies on the latest pm branch.
>
> Signed-off-by: Rajendra Nayak <rnayak@ti.com>

Thanks, applied to PM branch.

Kevin

> ---
>  arch/arm/mach-omap2/pm.c           |    6 +++++-
>  arch/arm/mach-omap2/resource34xx.c |   37 ++++++++++++++++++++++++++++---------
>  arch/arm/mach-omap2/resource34xx.h |   13 -------------
>  3 files changed, 33 insertions(+), 23 deletions(-)
>
> Index: linux-omap-2.6/arch/arm/mach-omap2/resource34xx.c
> ===================================================================
> --- linux-omap-2.6.orig/arch/arm/mach-omap2/resource34xx.c	2008-12-16 11:11:28.000000000 +0530
> +++ linux-omap-2.6/arch/arm/mach-omap2/resource34xx.c	2008-12-16 16:04:43.017689014 +0530
> @@ -146,7 +146,7 @@ void init_opp(struct shared_resource *re
>  	resp->no_of_users = 0;
>  
>  	if (!mpu_opps || !dsp_opps || !l3_opps)
> -		return 0;
> +		return;
>  
>  	/* Initialize the current level of the OPP resource
>  	* to the  opp set by u-boot.
> @@ -161,11 +161,12 @@ void init_opp(struct shared_resource *re
>  	return;
>  }
>  
> +static struct device vdd2_dev;
> +
>  int set_opp(struct shared_resource *resp, u32 target_level)
>  {
> -	unsigned long mpu_freq, mpu_old_freq, l3_freq, tput, t_opp;
> +	unsigned long mpu_freq, mpu_old_freq, l3_freq, req_l3_freq, tput, t_opp;
>  	int ind;
> -	struct bus_throughput_db *tput_db;
>  	struct cpufreq_freqs freqs_notify;
>  
>  	if (resp->curr_level == target_level)
> @@ -188,6 +189,14 @@ int set_opp(struct shared_resource *resp
>  #endif
>  		t_opp = ID_VDD(PRCM_VDD1) |
>  			ID_OPP_NO(mpu_opps[target_level].opp_id);
> +
> +		/* For VDD1 OPP3 and above, make sure the interconnect
> +		 * is at 100Mhz or above.
> +		 * throughput in KiB/s for 100 Mhz = 100 * 1000 * 4.
> +		 */
> +		if (mpu_opps[target_level].opp_id >= 3)
> +			resource_request("vdd2_opp", &vdd2_dev, 400000);
> +
>  		if (resp->curr_level > target_level) {
>  			/* Scale Frequency and then voltage */
>  			clk_set_rate(vdd1_clk, mpu_freq);
> @@ -203,22 +212,32 @@ int set_opp(struct shared_resource *resp
>  #endif
>  			clk_set_rate(vdd1_clk, mpu_freq);
>  		}
> +
> +		/* Release the VDD2/interconnect constraint */
> +		if (mpu_opps[target_level].opp_id < 3)
> +			resource_release("vdd2_opp", &vdd2_dev);
> +
>  		resp->curr_level = curr_vdd1_prcm_set->opp_id;
>  #ifdef CONFIG_CPU_FREQ
>  		/* Send a post notification to CPUFreq */
>  		cpufreq_notify_transition(&freqs_notify, CPUFREQ_POSTCHANGE);
>  #endif
>  	} else if (strcmp(resp->name, "vdd2_opp") == 0) {
> -		tput_db = resp->resource_data;
>  		tput = target_level;
> -		/* using the throughput db map to the appropriate L3 Freq */
> -		for (ind = 1; ind < MAX_VDD2_OPP; ind++)
> -			if (tput_db->throughput[ind] > tput)
> +
> +		/* Convert the tput in KiB/s to Bus frequency in Mhz*/
> +		req_l3_freq = (tput * 1000)/4;
> +
> +		for (ind = 2; ind <= MAX_VDD2_OPP; ind++) {
> +			if ((l3_opps + ind)->rate >= req_l3_freq) {
>  				target_level = ind;
> +				break;
> +			}
> +		}
>  
>  		/* Set the highest OPP possible */
> -		if (ind == MAX_VDD2_OPP)
> -			target_level = ind-1;
> +		if (ind > MAX_VDD2_OPP)
> +			target_level = MAX_VDD2_OPP;
>  
>  		if (resp->curr_level == target_level)
>  			return 0;
> Index: linux-omap-2.6/arch/arm/mach-omap2/pm.c
> ===================================================================
> --- linux-omap-2.6.orig/arch/arm/mach-omap2/pm.c	2008-12-16 10:35:55.000000000 +0530
> +++ linux-omap-2.6/arch/arm/mach-omap2/pm.c	2008-12-16 16:01:48.580075608 +0530
> @@ -34,6 +34,7 @@
>  #include <mach/powerdomain.h>
>  #include <mach/omapdev.h>
>  #include <mach/resource.h>
> +#include <mach/omap-pm.h>
>  
>  #include "prm-regbits-34xx.h"
>  #include "pm.h"
> @@ -136,6 +137,7 @@ static ssize_t vdd_opp_store(struct kobj
>  			  const char *buf, size_t n)
>  {
>  	unsigned short value;
> +	unsigned long bus_tput;
>  
>  	if (sscanf(buf, "%hu", &value) != 1)
>  		return -EINVAL;
> @@ -151,7 +153,9 @@ static ssize_t vdd_opp_store(struct kobj
>  			printk(KERN_ERR "vdd_opp_store: Invalid value\n");
>  			return -EINVAL;
>  		}
> -		resource_request("vdd2_opp", &dummy_sysfs_dev, value);
> +		/* Convert OPP's requested to appr. bus throughtput in KiB/s */
> +		bus_tput = ((l3_opps + value)->rate/1000) * 4;
> +		resource_request("vdd2_opp", &dummy_sysfs_dev, bus_tput);
>  	} else {
>  		return -EINVAL;
>  	}
> Index: linux-omap-2.6/arch/arm/mach-omap2/resource34xx.h
> ===================================================================
> --- linux-omap-2.6.orig/arch/arm/mach-omap2/resource34xx.h	2008-12-16 10:35:55.000000000 +0530
> +++ linux-omap-2.6/arch/arm/mach-omap2/resource34xx.h	2008-12-16 15:28:22.341172791 +0530
> @@ -238,11 +238,6 @@ void init_freq(struct shared_resource *r
>  int set_freq(struct shared_resource *resp, u32 target_level);
>  int validate_freq(struct shared_resource *resp, u32 target_level);
>  
> -struct bus_throughput_db {
> -	/* Throughput for each OPP/Freq of the bus */
> -	unsigned long throughput[3];
> -};
> -
>  static struct shared_resource_ops opp_res_ops = {
>  	.init           = init_opp,
>  	.change_level   = set_opp,
> @@ -255,17 +250,9 @@ static struct shared_resource vdd1_opp =
>  	.ops            = &opp_res_ops,
>  };
>  
> -/* Throughput in KiB/s */
> -static struct bus_throughput_db l3_throughput_db = {
> -	.throughput[0] = 0,
> -	.throughput[1] = 2656000,
> -	.throughput[2] = 5312000,
> -};
> -
>  static struct shared_resource vdd2_opp = {
>  	.name           = "vdd2_opp",
>  	.omap_chip      = OMAP_CHIP_INIT(CHIP_IS_OMAP3430),
> -	.resource_data  = &l3_throughput_db,
>  	.ops            = &opp_res_ops,
>  };
>  
>
> --
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