intel_mid_dma: Add runtime PM support
This patch adds runtime PM support in this dma driver
for 4 PCI Controllers
Whenever the driver is idle (no channels grabbed), it
can go to low power state
It also adds the PCI suspend and resume support
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
diff --git a/drivers/dma/intel_mid_dma.c b/drivers/dma/intel_mid_dma.c
index c2591e8..373396c 100644
--- a/drivers/dma/intel_mid_dma.c
+++ b/drivers/dma/intel_mid_dma.c
@@ -25,6 +25,7 @@
*/
#include <linux/pci.h>
#include <linux/interrupt.h>
+#include <linux/pm_runtime.h>
#include <linux/intel_mid_dma.h>
#define MAX_CHAN 4 /*max ch across controllers*/
@@ -247,13 +248,13 @@
struct middma_device *mid = to_middma_device(midc->chan.device);
/* channel is idle */
- if (midc->in_use && test_ch_en(midc->dma_base, midc->ch_id)) {
+ if (midc->busy && test_ch_en(midc->dma_base, midc->ch_id)) {
/*error*/
pr_err("ERR_MDMA: channel is busy in start\n");
/* The tasklet will hopefully advance the queue... */
return;
}
-
+ midc->busy = true;
/*write registers and en*/
iowrite32(first->sar, midc->ch_regs + SAR);
iowrite32(first->dar, midc->ch_regs + DAR);
@@ -290,7 +291,7 @@
param_txd = txd->callback_param;
list_move(&desc->desc_node, &midc->free_list);
-
+ midc->busy = false;
spin_unlock_bh(&midc->lock);
if (callback_txd) {
pr_debug("MDMA: TXD callback set ... calling\n");
@@ -434,7 +435,7 @@
return -ENXIO;
spin_lock_bh(&midc->lock);
- if (midc->in_use == false) {
+ if (midc->busy == false) {
spin_unlock_bh(&midc->lock);
return 0;
}
@@ -618,11 +619,11 @@
struct middma_device *mid = to_middma_device(chan->device);
struct intel_mid_dma_desc *desc, *_desc;
- if (true == midc->in_use) {
+ if (true == midc->busy) {
/*trying to free ch in use!!!!!*/
pr_err("ERR_MDMA: trying to free ch in use\n");
}
-
+ pm_runtime_put(&mid->pdev->dev);
spin_lock_bh(&midc->lock);
midc->descs_allocated = 0;
list_for_each_entry_safe(desc, _desc, &midc->active_list, desc_node) {
@@ -639,6 +640,7 @@
}
spin_unlock_bh(&midc->lock);
midc->in_use = false;
+ midc->busy = false;
/* Disable CH interrupts */
iowrite32(MASK_INTR_REG(midc->ch_id), mid->dma_base + MASK_BLOCK);
iowrite32(MASK_INTR_REG(midc->ch_id), mid->dma_base + MASK_ERR);
@@ -659,11 +661,20 @@
dma_addr_t phys;
int i = 0;
+ pm_runtime_get_sync(&mid->pdev->dev);
+
+ if (mid->state == SUSPENDED) {
+ if (dma_resume(mid->pdev)) {
+ pr_err("ERR_MDMA: resume failed");
+ return -EFAULT;
+ }
+ }
/* ASSERT: channel is idle */
if (test_ch_en(mid->dma_base, midc->ch_id)) {
/*ch is not idle*/
pr_err("ERR_MDMA: ch not idle\n");
+ pm_runtime_put(&mid->pdev->dev);
return -EIO;
}
midc->completed = chan->cookie = 1;
@@ -674,6 +685,7 @@
desc = pci_pool_alloc(mid->dma_pool, GFP_KERNEL, &phys);
if (!desc) {
pr_err("ERR_MDMA: desc failed\n");
+ pm_runtime_put(&mid->pdev->dev);
return -ENOMEM;
/*check*/
}
@@ -686,7 +698,8 @@
list_add_tail(&desc->desc_node, &midc->free_list);
}
spin_unlock_bh(&midc->lock);
- midc->in_use = false;
+ midc->in_use = true;
+ midc->busy = false;
pr_debug("MID_DMA: Desc alloc done ret: %d desc\n", i);
return i;
}
@@ -884,6 +897,7 @@
pr_debug("MDMA:Adding %d channel for this controller\n", dma->max_chan);
/*init CH structures*/
dma->intr_mask = 0;
+ dma->state = RUNNING;
for (i = 0; i < dma->max_chan; i++) {
struct intel_mid_dma_chan *midch = &dma->ch[i];
@@ -1070,6 +1084,9 @@
if (err)
goto err_dma;
+ pm_runtime_set_active(&pdev->dev);
+ pm_runtime_enable(&pdev->dev);
+ pm_runtime_allow(&pdev->dev);
return 0;
err_dma:
@@ -1104,6 +1121,85 @@
pci_disable_device(pdev);
}
+/* Power Management */
+/*
+* dma_suspend - PCI suspend function
+*
+* @pci: PCI device structure
+* @state: PM message
+*
+* This function is called by OS when a power event occurs
+*/
+int dma_suspend(struct pci_dev *pci, pm_message_t state)
+{
+ int i;
+ struct middma_device *device = pci_get_drvdata(pci);
+ pr_debug("MDMA: dma_suspend called\n");
+
+ for (i = 0; i < device->max_chan; i++) {
+ if (device->ch[i].in_use)
+ return -EAGAIN;
+ }
+ device->state = SUSPENDED;
+ pci_set_drvdata(pci, device);
+ pci_save_state(pci);
+ pci_disable_device(pci);
+ pci_set_power_state(pci, PCI_D3hot);
+ return 0;
+}
+
+/**
+* dma_resume - PCI resume function
+*
+* @pci: PCI device structure
+*
+* This function is called by OS when a power event occurs
+*/
+int dma_resume(struct pci_dev *pci)
+{
+ int ret;
+ struct middma_device *device = pci_get_drvdata(pci);
+
+ pr_debug("MDMA: dma_resume called\n");
+ pci_set_power_state(pci, PCI_D0);
+ pci_restore_state(pci);
+ ret = pci_enable_device(pci);
+ if (ret) {
+ pr_err("MDMA: device cant be enabled for %x\n", pci->device);
+ return ret;
+ }
+ device->state = RUNNING;
+ iowrite32(REG_BIT0, device->dma_base + DMA_CFG);
+ pci_set_drvdata(pci, device);
+ return 0;
+}
+
+static int dma_runtime_suspend(struct device *dev)
+{
+ struct pci_dev *pci_dev = to_pci_dev(dev);
+ return dma_suspend(pci_dev, PMSG_SUSPEND);
+}
+
+static int dma_runtime_resume(struct device *dev)
+{
+ struct pci_dev *pci_dev = to_pci_dev(dev);
+ return dma_resume(pci_dev);
+}
+
+static int dma_runtime_idle(struct device *dev)
+{
+ struct pci_dev *pdev = to_pci_dev(dev);
+ struct middma_device *device = pci_get_drvdata(pdev);
+ int i;
+
+ for (i = 0; i < device->max_chan; i++) {
+ if (device->ch[i].in_use)
+ return -EAGAIN;
+ }
+
+ return pm_schedule_suspend(dev, 0);
+}
+
/******************************************************************************
* PCI stuff
*/
@@ -1116,11 +1212,24 @@
};
MODULE_DEVICE_TABLE(pci, intel_mid_dma_ids);
+static const struct dev_pm_ops intel_mid_dma_pm = {
+ .runtime_suspend = dma_runtime_suspend,
+ .runtime_resume = dma_runtime_resume,
+ .runtime_idle = dma_runtime_idle,
+};
+
static struct pci_driver intel_mid_dma_pci = {
.name = "Intel MID DMA",
.id_table = intel_mid_dma_ids,
.probe = intel_mid_dma_probe,
.remove = __devexit_p(intel_mid_dma_remove),
+#ifdef CONFIG_PM
+ .suspend = dma_suspend,
+ .resume = dma_resume,
+ .driver = {
+ .pm = &intel_mid_dma_pm,
+ },
+#endif
};
static int __init intel_mid_dma_init(void)