>>-----Original Message----- >>From: Kevin Hilman [mailto:khilman@xxxxxxxxxxxxxxxxxxx] >>Sent: Friday, November 12, 2010 5:04 AM >>To: Gopinath, Thara >>Cc: linux-omap@xxxxxxxxxxxxxxx; paul@xxxxxxxxx; Cousson, Benoit; Sripathy, >>Vishwanath; Sawant, Anand >>Subject: Re: [PATCH v2 06/14] OMAP: Voltage layer changes to support DVFS. >> >>Thara Gopinath <thara@xxxxxx> writes: >> >>> This patch introduces an API to take in the voltage domain and the >>> new voltage as parameter and to scale all the scalable devices >>> associated with the the voltage domain to the rate corresponding to the >>> new voltage and scale the voltage domain to the new voltage. >>> >>> Signed-off-by: Thara Gopinath <thara@xxxxxx> >>> --- >>> arch/arm/mach-omap2/voltage.c | 72 >>+++++++++++++++++++++++++++++ >>> arch/arm/plat-omap/include/plat/voltage.h | 7 +++ >>> 2 files changed, 79 insertions(+), 0 deletions(-) >>> >>> diff --git a/arch/arm/mach-omap2/voltage.c b/arch/arm/mach-omap2/voltage.c >>> index 6c2e4ef..458f8c1 100644 >>> --- a/arch/arm/mach-omap2/voltage.c >>> +++ b/arch/arm/mach-omap2/voltage.c >>> @@ -27,9 +27,11 @@ >>> #include <linux/spinlock.h> >>> #include <linux/plist.h> >>> #include <linux/slab.h> >>> +#include <linux/opp.h> >>> >>> #include <plat/common.h> >>> #include <plat/voltage.h> >>> +#include <plat/omap_device.h> >>> >>> #include "prm-regbits-34xx.h" >>> #include "prm44xx.h" >>> @@ -1678,6 +1680,76 @@ struct voltagedomain >>*omap_voltage_domain_lookup(char *name) >>> } >>> >>> /** >>> + * omap_voltage_scale : API to scale the devices associated with a >>> + * voltage domain vdd voltage. >>> + * @volt_domain : the voltage domain to be scaled >>> + * @volt : the new voltage for the voltage domain >>> + * >>> + * This API runs through the list of devices associated with the >>> + * voltage domain and scales the device rates to those corresponding >>> + * to the new voltage of the voltage domain. This API also scales >>> + * the voltage domain voltage to the new value. Returns 0 on success >>> + * else the error value. >>> + */ >>> +int omap_voltage_scale(struct voltagedomain *voltdm, unsigned long volt) >>> +{ >>> + unsigned long curr_volt; >>> + int is_volt_scaled = 0; >>> + struct omap_vdd_info *vdd; >>> + struct omap_vdd_dev_list *temp_dev; >>> + >>> + if (!voltdm || IS_ERR(voltdm)) { >>> + pr_warning("%s: VDD specified does not exist!\n", __func__); >>> + return -EINVAL; >>> + } >>> + >>> + vdd = container_of(voltdm, struct omap_vdd_info, voltdm); >>> + >>> + mutex_lock(&vdd->scaling_mutex); >>> + >>> + curr_volt = omap_voltage_get_nom_volt(voltdm); >>> + >>> + if (curr_volt == volt) { >>> + is_volt_scaled = 1; >>> + } else if (curr_volt < volt) { >>> + omap_voltage_scale_vdd(voltdm, volt); >>> + is_volt_scaled = 1; >>> + } >>> + >>> + list_for_each_entry(temp_dev, &vdd->dev_list, node) { >>> + struct device *dev; >>> + struct opp *opp; >>> + unsigned long freq; >>> + >>> + dev = temp_dev->dev; >>> + >>> + opp = opp_find_voltage(dev, volt); >>> + if (IS_ERR(opp)) { >>> + dev_err(dev, "%s: Unable to find OPP for" >>> + "volt%ld\n", __func__, volt); >>> + continue; >>> + } >>> + >>> + freq = opp_get_freq(opp); >>> + >>> + if (freq == omap_device_get_rate(dev)) { >>> + dev_warn(dev, "%s: Already at the requested" >>> + "rate %ld\n", __func__, freq); >> >>Does this need to be a warning? This happens relatively often and is normal. >>This should probably just be removed in favor of >> >> if (freq != omap_device_get_rate(dev)) >> omap_device_set_rate(dev, freq); Yes. There are other warnings also in the dvfs code which could be removed. Will remove them all in the next version Regards Thara -- 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
