}
/**
- * pci_set_power_state - Set the power state of a PCI device
- * @dev: PCI device to be suspended
- * @state: PCI power state (D0, D1, D2, D3hot, D3cold) we're entering
+ * pci_raw_set_power_state - Use PCI PM registers to set the power state of
+ * given PCI device
+ * @dev: PCI device to handle.
+ * @pm: PCI PM capability offset of the device.
+ * @state: PCI power state (D0, D1, D2, D3hot) to put the device into.
*
- * Transition a device to a new power state, using the Power Management
- * Capabilities in the device's config space.
- *
- * RETURN VALUE:
- * -EINVAL if trying to enter a lower state than we're already in.
- * 0 if we're already in the requested state.
- * -EIO if device does not support PCI PM.
- * 0 if we can successfully change the power state.
+ * RETURN VALUE:
+ * -EINVAL if the requested state is invalid.
+ * -EIO if device does not support PCI PM or its PM capabilities register has a
+ * wrong version, or device doesn't support the requested state.
+ * 0 if device already is in the requested state.
+ * 0 if device's power state has been successfully changed.
*/
-int
-pci_set_power_state(struct pci_dev *dev, pci_power_t state)
+static int
+pci_raw_set_power_state(struct pci_dev *dev, int pm, pci_power_t state)
{
- int pm, need_restore = 0;
u16 pmcsr, pmc;
+ bool need_restore = false;
- /* bound the state we're entering */
- if (state > PCI_D3hot)
- state = PCI_D3hot;
-
- /*
- * If the device or the parent bridge can't support PCI PM, ignore
- * the request if we're doing anything besides putting it into D0
- * (which would only happen on boot).
- */
- if ((state == PCI_D1 || state == PCI_D2) && pci_no_d1d2(dev))
- return 0;
-
- /* find PCI PM capability in list */
- pm = pci_find_capability(dev, PCI_CAP_ID_PM);
-
- /* abort if the device doesn't support PM capabilities */
if (!pm)
return -EIO;
+ if (state < PCI_D0 || state > PCI_D3hot)
+ return -EINVAL;
+
/* Validate current state:
* Can enter D0 from any state, but if we can only go deeper
* to sleep if we're already in a low power state
*/
- if (state != PCI_D0 && dev->current_state > state) {
+ if (dev->current_state == state) {
+ /* we're already there */
+ return 0;
+ } else if (state != PCI_D0 && dev->current_state <= PCI_D3cold
+ && dev->current_state > state) {
dev_err(&dev->dev, "invalid power transition "
"(from state %d to %d)\n", dev->current_state, state);
return -EINVAL;
- } else if (dev->current_state == state)
- return 0; /* we're already there */
+ }
+ pci_read_config_word(dev, pm + PCI_PM_PMC, &pmc);
- pci_read_config_word(dev,pm + PCI_PM_PMC,&pmc);
if ((pmc & PCI_PM_CAP_VER_MASK) > 3) {
- dev_printk(KERN_DEBUG, &dev->dev, "unsupported PM cap regs "
- "version (%u)\n", pmc & PCI_PM_CAP_VER_MASK);
+ dev_err(&dev->dev, "unsupported PM cap regs version (%u)\n",
+ pmc & PCI_PM_CAP_VER_MASK);
return -EIO;
}
/* check if this device supports the desired state */
- if (state == PCI_D1 && !(pmc & PCI_PM_CAP_D1))
- return -EIO;
- else if (state == PCI_D2 && !(pmc & PCI_PM_CAP_D2))
+ if ((state == PCI_D1 && !(pmc & PCI_PM_CAP_D1))
+ || (state == PCI_D2 && !(pmc & PCI_PM_CAP_D2)))
return -EIO;
pci_read_config_word(dev, pm + PCI_PM_CTRL, &pmcsr);
case PCI_UNKNOWN: /* Boot-up */
if ((pmcsr & PCI_PM_CTRL_STATE_MASK) == PCI_D3hot
&& !(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET))
- need_restore = 1;
+ need_restore = true;
/* Fall-through: force to D0 */
default:
pmcsr = 0;
else if (state == PCI_D2 || dev->current_state == PCI_D2)
udelay(200);
- /*
- * Give firmware a chance to be called, such as ACPI _PRx, _PSx
- * Firmware method after native method ?
- */
- platform_pci_set_power_state(dev, state);
-
dev->current_state = state;
/* According to section 5.4.1 of the "PCI BUS POWER MANAGEMENT
return 0;
}
+/**
+ * pci_update_current_state - Read PCI power state of given device from its
+ * PCI PM registers and cache it
+ * @dev: PCI device to handle.
+ * @pm: PCI PM capability offset of the device.
+ */
+static void pci_update_current_state(struct pci_dev *dev, int pm)
+{
+ if (pm) {
+ u16 pmcsr;
+
+ pci_read_config_word(dev, pm + PCI_PM_CTRL, &pmcsr);
+ dev->current_state = (pmcsr & PCI_PM_CTRL_STATE_MASK);
+ }
+}
+
+/**
+ * pci_set_power_state - Set the power state of a PCI device
+ * @dev: PCI device to handle.
+ * @state: PCI power state (D0, D1, D2, D3hot) to put the device into.
+ *
+ * Transition a device to a new power state, using the platform formware and/or
+ * the device's PCI PM registers.
+ *
+ * RETURN VALUE:
+ * -EINVAL if the requested state is invalid.
+ * -EIO if device does not support PCI PM or its PM capabilities register has a
+ * wrong version, or device doesn't support the requested state.
+ * 0 if device already is in the requested state.
+ * 0 if device's power state has been successfully changed.
+ */
+int pci_set_power_state(struct pci_dev *dev, pci_power_t state)
+{
+ int pm, error;
+
+ /* bound the state we're entering */
+ if (state > PCI_D3hot)
+ state = PCI_D3hot;
+ else if (state < PCI_D0)
+ state = PCI_D0;
+ else if ((state == PCI_D1 || state == PCI_D2) && pci_no_d1d2(dev))
+ /*
+ * If the device or the parent bridge do not support PCI PM,
+ * ignore the request if we're doing anything other than putting
+ * it into D0 (which would only happen on boot).
+ */
+ return 0;
+
+ /* Find PCI PM capability in the list */
+ pm = pci_find_capability(dev, PCI_CAP_ID_PM);
+
+ if (state == PCI_D0 && platform_pci_power_manageable(dev)) {
+ /*
+ * Allow the platform to change the state, for example via ACPI
+ * _PR0, _PS0 and some such, but do not trust it.
+ */
+ int ret = platform_pci_set_power_state(dev, PCI_D0);
+ if (!ret)
+ pci_update_current_state(dev, pm);
+ }
+
+ error = pci_raw_set_power_state(dev, pm, state);
+
+ if (state > PCI_D0 && platform_pci_power_manageable(dev)) {
+ /* Allow the platform to finalize the transition */
+ int ret = platform_pci_set_power_state(dev, state);
+ if (!ret) {
+ pci_update_current_state(dev, pm);
+ error = 0;
+ }
+ }
+
+ return error;
+}
+
/**
* pci_choose_state - Choose the power state of a PCI device
* @dev: PCI device to be suspended
projects / linux-2.6-omap-h63xx.git / blobdiff