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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>
This commit is contained in:
Laxman Dewangan 2013-04-24 15:24:27 +05:30 committed by Vinod Koul
parent b2396f7984
commit 3065c19467
1 changed files with 65 additions and 0 deletions
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65
drivers/dma/tegra20-apb-dma.c
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@ -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 = {