diff options
Diffstat (limited to 'drivers/dma/sirf-dma.c')
| -rw-r--r-- | drivers/dma/sirf-dma.c | 134 |
1 files changed, 130 insertions, 4 deletions
diff --git a/drivers/dma/sirf-dma.c b/drivers/dma/sirf-dma.c index 716b23e4f327..6aec3ad814d3 100644 --- a/drivers/dma/sirf-dma.c +++ b/drivers/dma/sirf-dma.c @@ -9,6 +9,7 @@ #include <linux/module.h> #include <linux/dmaengine.h> #include <linux/dma-mapping.h> +#include <linux/pm_runtime.h> #include <linux/interrupt.h> #include <linux/io.h> #include <linux/slab.h> @@ -73,6 +74,11 @@ struct sirfsoc_dma_chan { int mode; }; +struct sirfsoc_dma_regs { + u32 ctrl[SIRFSOC_DMA_CHANNELS]; + u32 interrupt_en; +}; + struct sirfsoc_dma { struct dma_device dma; struct tasklet_struct tasklet; @@ -81,10 +87,13 @@ struct sirfsoc_dma { int irq; struct clk *clk; bool is_marco; + struct sirfsoc_dma_regs regs_save; }; #define DRV_NAME "sirfsoc_dma" +static int sirfsoc_dma_runtime_suspend(struct device *dev); + /* Convert struct dma_chan to struct sirfsoc_dma_chan */ static inline struct sirfsoc_dma_chan *dma_chan_to_sirfsoc_dma_chan(struct dma_chan *c) @@ -393,6 +402,8 @@ static int sirfsoc_dma_alloc_chan_resources(struct dma_chan *chan) LIST_HEAD(descs); int i; + pm_runtime_get_sync(sdma->dma.dev); + /* Alloc descriptors for this channel */ for (i = 0; i < SIRFSOC_DMA_DESCRIPTORS; i++) { sdesc = kzalloc(sizeof(*sdesc), GFP_KERNEL); @@ -425,6 +436,7 @@ static int sirfsoc_dma_alloc_chan_resources(struct dma_chan *chan) static void sirfsoc_dma_free_chan_resources(struct dma_chan *chan) { struct sirfsoc_dma_chan *schan = dma_chan_to_sirfsoc_dma_chan(chan); + struct sirfsoc_dma *sdma = dma_chan_to_sirfsoc_dma(chan); struct sirfsoc_dma_desc *sdesc, *tmp; unsigned long flags; LIST_HEAD(descs); @@ -445,6 +457,8 @@ static void sirfsoc_dma_free_chan_resources(struct dma_chan *chan) /* Free descriptors */ list_for_each_entry_safe(sdesc, tmp, &descs, node) kfree(sdesc); + + pm_runtime_put(sdma->dma.dev); } /* Send pending descriptor to hardware */ @@ -595,7 +609,7 @@ sirfsoc_dma_prep_cyclic(struct dma_chan *chan, dma_addr_t addr, spin_unlock_irqrestore(&schan->lock, iflags); if (!sdesc) - return 0; + return NULL; /* Place descriptor in prepared list */ spin_lock_irqsave(&schan->lock, iflags); @@ -723,14 +737,14 @@ static int sirfsoc_dma_probe(struct platform_device *op) tasklet_init(&sdma->tasklet, sirfsoc_dma_tasklet, (unsigned long)sdma); - clk_prepare_enable(sdma->clk); - /* Register DMA engine */ dev_set_drvdata(dev, sdma); + ret = dma_async_device_register(dma); if (ret) goto free_irq; + pm_runtime_enable(&op->dev); dev_info(dev, "initialized SIRFSOC DMAC driver\n"); return 0; @@ -747,13 +761,124 @@ static int sirfsoc_dma_remove(struct platform_device *op) struct device *dev = &op->dev; struct sirfsoc_dma *sdma = dev_get_drvdata(dev); - clk_disable_unprepare(sdma->clk); dma_async_device_unregister(&sdma->dma); free_irq(sdma->irq, sdma); irq_dispose_mapping(sdma->irq); + pm_runtime_disable(&op->dev); + if (!pm_runtime_status_suspended(&op->dev)) + sirfsoc_dma_runtime_suspend(&op->dev); + + return 0; +} + +static int sirfsoc_dma_runtime_suspend(struct device *dev) +{ + struct sirfsoc_dma *sdma = dev_get_drvdata(dev); + + clk_disable_unprepare(sdma->clk); + return 0; +} + +static int sirfsoc_dma_runtime_resume(struct device *dev) +{ + struct sirfsoc_dma *sdma = dev_get_drvdata(dev); + int ret; + + ret = clk_prepare_enable(sdma->clk); + if (ret < 0) { + dev_err(dev, "clk_enable failed: %d\n", ret); + return ret; + } + return 0; +} + +static int sirfsoc_dma_pm_suspend(struct device *dev) +{ + struct sirfsoc_dma *sdma = dev_get_drvdata(dev); + struct sirfsoc_dma_regs *save = &sdma->regs_save; + struct sirfsoc_dma_desc *sdesc; + struct sirfsoc_dma_chan *schan; + int ch; + int ret; + + /* + * if we were runtime-suspended before, resume to enable clock + * before accessing register + */ + if (pm_runtime_status_suspended(dev)) { + ret = sirfsoc_dma_runtime_resume(dev); + if (ret < 0) + return ret; + } + + /* + * DMA controller will lose all registers while suspending + * so we need to save registers for active channels + */ + for (ch = 0; ch < SIRFSOC_DMA_CHANNELS; ch++) { + schan = &sdma->channels[ch]; + if (list_empty(&schan->active)) + continue; + sdesc = list_first_entry(&schan->active, + struct sirfsoc_dma_desc, + node); + save->ctrl[ch] = readl_relaxed(sdma->base + + ch * 0x10 + SIRFSOC_DMA_CH_CTRL); + } + save->interrupt_en = readl_relaxed(sdma->base + SIRFSOC_DMA_INT_EN); + + /* Disable clock */ + sirfsoc_dma_runtime_suspend(dev); + + return 0; +} + +static int sirfsoc_dma_pm_resume(struct device *dev) +{ + struct sirfsoc_dma *sdma = dev_get_drvdata(dev); + struct sirfsoc_dma_regs *save = &sdma->regs_save; + struct sirfsoc_dma_desc *sdesc; + struct sirfsoc_dma_chan *schan; + int ch; + int ret; + + /* Enable clock before accessing register */ + ret = sirfsoc_dma_runtime_resume(dev); + if (ret < 0) + return ret; + + writel_relaxed(save->interrupt_en, sdma->base + SIRFSOC_DMA_INT_EN); + for (ch = 0; ch < SIRFSOC_DMA_CHANNELS; ch++) { + schan = &sdma->channels[ch]; + if (list_empty(&schan->active)) + continue; + sdesc = list_first_entry(&schan->active, + struct sirfsoc_dma_desc, + node); + writel_relaxed(sdesc->width, + sdma->base + SIRFSOC_DMA_WIDTH_0 + ch * 4); + writel_relaxed(sdesc->xlen, + sdma->base + ch * 0x10 + SIRFSOC_DMA_CH_XLEN); + writel_relaxed(sdesc->ylen, + sdma->base + ch * 0x10 + SIRFSOC_DMA_CH_YLEN); + writel_relaxed(save->ctrl[ch], + sdma->base + ch * 0x10 + SIRFSOC_DMA_CH_CTRL); + writel_relaxed(sdesc->addr >> 2, + sdma->base + ch * 0x10 + SIRFSOC_DMA_CH_ADDR); + } + + /* if we were runtime-suspended before, suspend again */ + if (pm_runtime_status_suspended(dev)) + sirfsoc_dma_runtime_suspend(dev); + return 0; } +static const struct dev_pm_ops sirfsoc_dma_pm_ops = { + SET_RUNTIME_PM_OPS(sirfsoc_dma_runtime_suspend, sirfsoc_dma_runtime_resume, NULL) + SET_SYSTEM_SLEEP_PM_OPS(sirfsoc_dma_pm_suspend, sirfsoc_dma_pm_resume) +}; + static struct of_device_id sirfsoc_dma_match[] = { { .compatible = "sirf,prima2-dmac", }, { .compatible = "sirf,marco-dmac", }, @@ -766,6 +891,7 @@ static struct platform_driver sirfsoc_dma_driver = { .driver = { .name = DRV_NAME, .owner = THIS_MODULE, + .pm = &sirfsoc_dma_pm_ops, .of_match_table = sirfsoc_dma_match, }, }; |