shinys000114/linux
1
0
Fork 0
mirror of https://github.com/hardkernel/linux.git synced 2026-06-11 05:17:10 +09:00
Code Issues Packages Projects Releases Wiki Activity

[ARM] Tegra: SPI: Suspend/resume.

Browse Source 
Save/restore SLINK_COMMAND_0 register.

Wait for in-progress transactions to complete before suspend.

Reject and WARN_ON transactions when suspended.

Change-Id: I0527781f0bf95781afa3a35a68282cde2f0189ae
Signed-off-by: Todd Poynor <toddpoynor@google.com>
This commit is contained in:
Todd Poynor
2010-07-30 12:09:22 -07:00
committed by Colin Cross
parent 0d2beae104
commit 6bdd0cc0ef
1 changed files with 57 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

58
drivers/spi/spi_tegra.c
View File

@@ -165,6 +165,8 @@ struct spi_tegra_data {
struct tegra_dma_channel *rx_dma;
u32 *rx_bb;
dma_addr_t rx_bb_phys;
bool is_suspended;
unsigned long save_slink_cmd;
};
@@ -450,9 +452,15 @@ static int spi_tegra_transfer(struct spi_device *spi, struct spi_message *m)
return -EINVAL;
}
spin_lock_irqsave(&tspi->lock, flags);
if (WARN_ON(tspi->is_suspended)) {
spin_unlock_irqrestore(&tspi->lock, flags);
return -EBUSY;
}
m->state = spi;
spin_lock_irqsave(&tspi->lock, flags);
was_empty = list_empty(&tspi->queue);
list_add_tail(&m->queue, &tspi->queue);
@@ -600,6 +608,50 @@ static int __devexit spi_tegra_remove(struct platform_device *pdev)
return 0;
}
#ifdef CONFIG_PM
static int spi_tegra_suspend(struct platform_device *pdev, pm_message_t state)
{
struct spi_master *master;
struct spi_tegra_data *tspi;
unsigned long flags;
unsigned limit = 500;
master = dev_get_drvdata(&pdev->dev);
tspi = spi_master_get_devdata(master);
spin_lock_irqsave(&tspi->lock, flags);
tspi->is_suspended = true;
WARN_ON(!list_empty(&tspi->queue));
while (!list_empty(&tspi->queue) && limit--) {
spin_unlock_irqrestore(&tspi->lock, flags);
msleep(10);
spin_lock_irqsave(&tspi->lock, flags);
}
tspi->save_slink_cmd = spi_tegra_readl(tspi, SLINK_COMMAND);
spin_unlock_irqrestore(&tspi->lock, flags);
return 0;
}
static int spi_tegra_resume(struct platform_device *pdev)
{
struct spi_master *master;
struct spi_tegra_data *tspi;
unsigned long flags;
master = dev_get_drvdata(&pdev->dev);
tspi = spi_master_get_devdata(master);
spin_lock_irqsave(&tspi->lock, flags);
clk_enable(tspi->clk);
spi_tegra_writel(tspi, tspi->save_slink_cmd, SLINK_COMMAND);
clk_disable(tspi->clk);
tspi->cur_speed = 0;
tspi->is_suspended = false;
spin_unlock_irqrestore(&tspi->lock, flags);
return 0;
}
#endif
MODULE_ALIAS("platform:spi_tegra");
static struct platform_driver spi_tegra_driver = {
@@ -608,6 +660,10 @@ static struct platform_driver spi_tegra_driver = {
.owner = THIS_MODULE,
},
.remove = __devexit_p(spi_tegra_remove),
#ifdef CONFIG_PM
.suspend = spi_tegra_suspend,
.resume = spi_tegra_resume,
#endif
};
static int __init spi_tegra_init(void)