/**
* omap_device_set_rate - Set a new rate at which the device is to operate
* @req_dev : pointer to the device requesting the scaling.
* @dev : pointer to the device that is to be scaled
* @rate : the rnew rate for the device.
*
* This API gets the device opp table associated with this device and
* tries putting the device to the requested rate and the voltage domain
* associated with the device to the voltage corresponding to the
* requested rate. Since multiple devices can be assocciated with a
* voltage domain this API finds out the possible voltage the
* voltage domain can enter and then decides on the final device
* rate. Return 0 on success else the error value
*/
int omap_device_set_rate(struct device *req_dev, struct device *dev,
unsigned long rate)
{
struct omap_opp *opp;
unsigned long volt, freq, min_freq, max_freq, flags;
struct voltagedomain *voltdm;
struct platform_device *pdev;
struct omap_device *od;
int ret;
pdev = container_of(dev, struct platform_device, dev);
od = _find_by_pdev(pdev);
/* if in low power DPLL cascading mode, bail out early */
if (cpu_is_omap44xx()) {
read_lock_irqsave(&dpll_cascading_lock, flags);
if (in_dpll_cascading) {
ret = -EINVAL;
goto out;
}
}
/*
* Figure out if the desired frquency lies between the
* maximum and minimum possible for the particular device
*/
min_freq = 0;
if (IS_ERR(opp_find_freq_ceil(dev, &min_freq))) {
dev_err(dev, "%s: Unable to find lowest opp\n", __func__);
ret = -ENODEV;
goto out;
}
max_freq = ULONG_MAX;
if (IS_ERR(opp_find_freq_floor(dev, &max_freq))) {
dev_err(dev, "%s: Unable to find highest opp\n", __func__);
ret = -ENODEV;
goto out;
}
if (rate < min_freq)
freq = min_freq;
else if (rate > max_freq)
freq = max_freq;
else
freq = rate;
/* Get the possible rate from the opp layer */
opp = opp_find_freq_ceil(dev, &freq);
if (IS_ERR(opp)) {
dev_dbg(dev, "%s: Unable to find OPP for freq%ld\n",
__func__, rate);
ret = -ENODEV;
goto out;
}
if (unlikely(freq != rate))
dev_dbg(dev, "%s: Available freq %ld != dpll freq %ld.\n",
__func__, freq, rate);
/* Get the voltage corresponding to the requested frequency */
volt = opp_get_voltage(opp);
/*
* Call into the voltage layer to get the final voltage possible
* for the voltage domain associated with the device.
*/
voltdm = od->hwmods[0]->voltdm;
ret = omap_voltage_add_userreq(voltdm, req_dev, &volt);
if (ret) {
dev_err(dev, "%s: Unable to get the final volt for scaling\n",
__func__);
goto out;
}
/* Do the actual scaling */
ret = omap_voltage_scale(voltdm);
out:
if (cpu_is_omap44xx())
read_unlock_irqrestore(&dpll_cascading_lock, flags);
return ret;
}
/**
* omap_device_scale() - Set a new rate at which the device is to operate
* @req_dev: pointer to the device requesting the scaling.
* @dev: pointer to the device that is to be scaled
* @rate: the rnew rate for the device.
*
* This API gets the device opp table associated with this device and
* tries putting the device to the requested rate and the voltage domain
* associated with the device to the voltage corresponding to the
* requested rate. Since multiple devices can be assocciated with a
* voltage domain this API finds out the possible voltage the
* voltage domain can enter and then decides on the final device
* rate. Return 0 on success else the error value
*/
int omap_device_scale(struct device *req_dev, struct device *dev,
unsigned long rate)
{
struct opp *opp;
unsigned long volt, freq, min_freq, max_freq;
struct voltagedomain *voltdm;
struct platform_device *pdev;
struct omap_device *od;
int ret;
pdev = container_of(dev, struct platform_device, dev);
od = _find_by_pdev(pdev);
/*
* Figure out if the desired frquency lies between the
* maximum and minimum possible for the particular device
*/
min_freq = 0;
if (IS_ERR(opp_find_freq_ceil(dev, &min_freq))) {
dev_err(dev, "%s: Unable to find lowest opp\n", __func__);
return -ENODEV;
}
max_freq = ULONG_MAX;
if (IS_ERR(opp_find_freq_floor(dev, &max_freq))) {
dev_err(dev, "%s: Unable to find highest opp\n", __func__);
return -ENODEV;
}
if (rate < min_freq)
freq = min_freq;
else if (rate > max_freq)
freq = max_freq;
else
freq = rate;
opp = opp_find_freq_ceil(dev, &freq);
if (IS_ERR(opp)) {
dev_err(dev, "%s: Unable to find OPP for freq%ld\n",
__func__, rate);
return -ENODEV;
}
/* Get the voltage corresponding to the requested frequency */
volt = opp_get_voltage(opp);
/*
* Call into the voltage layer to get the final voltage possible
* for the voltage domain associated with the device.
*/
voltdm = od->hwmods[0]->voltdm;
ret = omap_voltage_add_request(voltdm, req_dev, &volt);
if (ret) {
dev_err(dev, "%s: Unable to get the final volt for scaling\n",
__func__);
return ret;
}
/* Do the actual scaling */
return omap_voltage_scale(voltdm, volt);
}
