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authorLaxman Dewangan <ldewangan@nvidia.com>2013-04-24 15:24:27 +0530
committerVinod Koul <vinod.koul@intel.com>2013-05-02 22:19:20 +0530
commit3065c194670b61e213656ce25976d7c8a95e3c93 (patch)
treef2d9b86bbe35623d9885f517f38c965f569675af
parentMerge branch 'topic/of' into for-linus (diff)
downloadlinux-dev-3065c194670b61e213656ce25976d7c8a95e3c93.tar.xz
linux-dev-3065c194670b61e213656ce25976d7c8a95e3c93.zip
dma: tegra: implement suspend/resume callbacks
Implement suspend/resume callbacks to store APB DMA channel's register on suspend and restore APB DMA channel's register on resume. Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
-rw-r--r--drivers/dma/tegra20-apb-dma.c65
1 files changed, 65 insertions, 0 deletions
diff --git a/drivers/dma/tegra20-apb-dma.c b/drivers/dma/tegra20-apb-dma.c
index 5a0b66c2a60c..ce193409ebd3 100644
--- a/drivers/dma/tegra20-apb-dma.c
+++ b/drivers/dma/tegra20-apb-dma.c
@@ -30,6 +30,7 @@
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
+#include <linux/pm.h>
#include <linux/pm_runtime.h>
#include <linux/slab.h>
#include <linux/clk/tegra.h>
@@ -199,6 +200,7 @@ struct tegra_dma_channel {
/* Channel-slave specific configuration */
struct dma_slave_config dma_sconfig;
+ struct tegra_dma_channel_regs channel_reg;
};
/* tegra_dma: Tegra DMA specific information */
@@ -1440,11 +1442,74 @@ static int tegra_dma_runtime_resume(struct device *dev)
return 0;
}
+#ifdef CONFIG_PM_SLEEP
+static int tegra_dma_pm_suspend(struct device *dev)
+{
+ struct tegra_dma *tdma = dev_get_drvdata(dev);
+ int i;
+ int ret;
+
+ /* Enable clock before accessing register */
+ ret = tegra_dma_runtime_resume(dev);
+ if (ret < 0)
+ return ret;
+
+ tdma->reg_gen = tdma_read(tdma, TEGRA_APBDMA_GENERAL);
+ for (i = 0; i < tdma->chip_data->nr_channels; i++) {
+ struct tegra_dma_channel *tdc = &tdma->channels[i];
+ struct tegra_dma_channel_regs *ch_reg = &tdc->channel_reg;
+
+ ch_reg->csr = tdc_read(tdc, TEGRA_APBDMA_CHAN_CSR);
+ ch_reg->ahb_ptr = tdc_read(tdc, TEGRA_APBDMA_CHAN_AHBPTR);
+ ch_reg->apb_ptr = tdc_read(tdc, TEGRA_APBDMA_CHAN_APBPTR);
+ ch_reg->ahb_seq = tdc_read(tdc, TEGRA_APBDMA_CHAN_AHBSEQ);
+ ch_reg->apb_seq = tdc_read(tdc, TEGRA_APBDMA_CHAN_APBSEQ);
+ }
+
+ /* Disable clock */
+ tegra_dma_runtime_suspend(dev);
+ return 0;
+}
+
+static int tegra_dma_pm_resume(struct device *dev)
+{
+ struct tegra_dma *tdma = dev_get_drvdata(dev);
+ int i;
+ int ret;
+
+ /* Enable clock before accessing register */
+ ret = tegra_dma_runtime_resume(dev);
+ if (ret < 0)
+ return ret;
+
+ tdma_write(tdma, TEGRA_APBDMA_GENERAL, tdma->reg_gen);
+ tdma_write(tdma, TEGRA_APBDMA_CONTROL, 0);
+ tdma_write(tdma, TEGRA_APBDMA_IRQ_MASK_SET, 0xFFFFFFFFul);
+
+ for (i = 0; i < tdma->chip_data->nr_channels; i++) {
+ struct tegra_dma_channel *tdc = &tdma->channels[i];
+ struct tegra_dma_channel_regs *ch_reg = &tdc->channel_reg;
+
+ tdc_write(tdc, TEGRA_APBDMA_CHAN_APBSEQ, ch_reg->apb_seq);
+ tdc_write(tdc, TEGRA_APBDMA_CHAN_APBPTR, ch_reg->apb_ptr);
+ tdc_write(tdc, TEGRA_APBDMA_CHAN_AHBSEQ, ch_reg->ahb_seq);
+ tdc_write(tdc, TEGRA_APBDMA_CHAN_AHBPTR, ch_reg->ahb_ptr);
+ tdc_write(tdc, TEGRA_APBDMA_CHAN_CSR,
+ (ch_reg->csr & ~TEGRA_APBDMA_CSR_ENB));
+ }
+
+ /* Disable clock */
+ tegra_dma_runtime_suspend(dev);
+ return 0;
+}
+#endif
+
static const struct dev_pm_ops tegra_dma_dev_pm_ops = {
#ifdef CONFIG_PM_RUNTIME
.runtime_suspend = tegra_dma_runtime_suspend,
.runtime_resume = tegra_dma_runtime_resume,
#endif
+ SET_SYSTEM_SLEEP_PM_OPS(tegra_dma_pm_suspend, tegra_dma_pm_resume)
};
static struct platform_driver tegra_dmac_driver = {