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 (file)
--- 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 @@ static void midc_dostart(struct intel_mid_dma_chan *midc,
        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 @@ static void midc_descriptor_complete(struct intel_mid_dma_chan *midc,
        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 @@ static int intel_mid_dma_device_control(struct dma_chan *chan,
                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 @@ static void intel_mid_dma_free_chan_resources(struct dma_chan *chan)
        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 @@ static void intel_mid_dma_free_chan_resources(struct dma_chan *chan)
        }
        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 @@ static int intel_mid_dma_alloc_chan_resources(struct dma_chan *chan)
        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 @@ static int intel_mid_dma_alloc_chan_resources(struct dma_chan *chan)
                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 @@ static int intel_mid_dma_alloc_chan_resources(struct dma_chan *chan)
                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 @@ static int mid_setup_dma(struct pci_dev *pdev)
        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 @@ static int __devinit intel_mid_dma_probe(struct pci_dev *pdev,
        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 @@ static void __devexit intel_mid_dma_remove(struct pci_dev *pdev)
        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 @@ static struct pci_device_id intel_mid_dma_ids[] = {
 };
 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)

diff --git a/drivers/dma/intel_mid_dma_regs.h b/drivers/dma/intel_mid_dma_regs.h
index d81aa65..a12dd25 100644 (file)
--- a/drivers/dma/intel_mid_dma_regs.h
+++ b/drivers/dma/intel_mid_dma_regs.h
@@ -29,7 +29,7 @@
 #include <linux/dmapool.h>
 #include <linux/pci_ids.h>
 
-#define INTEL_MID_DMA_DRIVER_VERSION "1.0.5"
+#define INTEL_MID_DMA_DRIVER_VERSION "1.0.6"
 
 #define        REG_BIT0                0x00000001
 #define        REG_BIT8                0x00000100
@@ -152,6 +152,7 @@ union intel_mid_dma_cfg_hi {
        u32     cfg_hi;
 };
 
+
 /**
  * struct intel_mid_dma_chan - internal mid representation of a DMA channel
  * @chan: dma_chan strcture represetation for mid chan
@@ -166,6 +167,7 @@ union intel_mid_dma_cfg_hi {
  * @slave: dma slave struture
  * @descs_allocated: total number of decsiptors allocated
  * @dma: dma device struture pointer
+ * @busy: bool representing if ch is busy (active txn) or not
  * @in_use: bool representing if ch is in use or not
  */
 struct intel_mid_dma_chan {
@@ -181,6 +183,7 @@ struct intel_mid_dma_chan {
        struct intel_mid_dma_slave      *slave;
        unsigned int            descs_allocated;
        struct middma_device    *dma;
+       bool                    busy;
        bool                    in_use;
 };
 
@@ -190,6 +193,10 @@ static inline struct intel_mid_dma_chan *to_intel_mid_dma_chan(
        return container_of(chan, struct intel_mid_dma_chan, chan);
 }
 
+enum intel_mid_dma_state {
+       RUNNING = 0,
+       SUSPENDED,
+};
 /**
  * struct middma_device - internal representation of a DMA device
  * @pdev: PCI device
@@ -205,6 +212,7 @@ static inline struct intel_mid_dma_chan *to_intel_mid_dma_chan(
  * @max_chan: max number of chs supported (from drv_data)
  * @block_size: Block size of DMA transfer supported (from drv_data)
  * @pimr_mask: MMIO register addr for periphral interrupt (from drv_data)
+ * @state: dma PM device state
  */
 struct middma_device {
        struct pci_dev          *pdev;
@@ -220,6 +228,7 @@ struct middma_device {
        int                     max_chan;
        int                     block_size;
        unsigned int            pimr_mask;
+       enum intel_mid_dma_state state;
 };
 
 static inline struct middma_device *to_middma_device(struct dma_device *common)
@@ -257,4 +266,7 @@ static inline struct intel_mid_dma_desc *to_intel_mid_dma_desc
 {
        return container_of(txd, struct intel_mid_dma_desc, txd);
 }
+
+int dma_resume(struct pci_dev *pci);
+
 #endif /*__INTEL_MID_DMAC_REGS_H__*/