spi: tegra: macro for enable/disable runtime pm inside driver

Add macro in the spi tegra driver for enabling/disabling
runtime PM specific to this driver.
Setting macro SPI_PM_RUNTIME_ENABLE to 1 will enable the
runtime pm and resetting to 0 make runtime pm disable.

The dynamic clock management i.e. enabling the clock before
transfer and disabling after transfer complete is done in
both the cases.
When runtime pm is enabled then clock control is done through
runtime pm callbacks otherwise it will be directly call the
clock control apis.

bug 1003103

Change-Id: I2544e8f3b3e5605e0247791653a5a0ed6c36e9b6
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Reviewed-on: http://git-master/r/112142
Reviewed-by: Automatic_Commit_Validation_User

1 files changed, 81 insertions, 33 deletions

diff --git a/drivers/spi/spi-tegra.c b/drivers/spi/spi-tegra.c
index c0de42bf4299..cf1b7bf40c62 100644
--- a/drivers/spi/spi-tegra.c
+++ b/drivers/spi/spi-tegra.c
@@ -42,6 +42,8 @@
 #include <mach/dma.h>
 #include <mach/clk.h>
 
+#define SPI_PM_RUNTIME_ENABLE 0
+
 #define SLINK_COMMAND		0x000
 #define   SLINK_BIT_LENGTH(x)		(((x) & 0x1f) << 0)
 #define   SLINK_WORD_SIZE(x)		(((x) & 0x1f) << 5)
@@ -174,6 +176,7 @@ struct spi_tegra_data {
 	struct spi_master	*master;
 	struct platform_device	*pdev;
 	spinlock_t		lock;
+	spinlock_t		reg_lock;
 	char			port_name[32];
 
 	struct clk		*clk;
@@ -214,7 +217,7 @@ struct spi_tegra_data {
 	bool			is_curr_dma_xfer;
 
 	bool			is_clkon_always;
-	bool			clk_state;
+	int			clk_state;
 	bool			is_suspended;
 
 	bool			is_hw_based_cs;
@@ -252,22 +255,75 @@ static int tegra_spi_runtime_resume(struct device *dev);
 static inline unsigned long spi_tegra_readl(struct spi_tegra_data *tspi,
 		    unsigned long reg)
 {
-	if (!tspi->clk_state)
+	unsigned long flags;
+	unsigned long val;
+
+	spin_lock_irqsave(&tspi->reg_lock, flags);
+	if (tspi->clk_state < 1)
 		BUG();
-	return readl(tspi->base + reg);
+	val = readl(tspi->base + reg);
+	spin_unlock_irqrestore(&tspi->reg_lock, flags);
+	return val;
 }
 
 static inline void spi_tegra_writel(struct spi_tegra_data *tspi,
 		    unsigned long val, unsigned long reg)
 {
-	if (!tspi->clk_state)
+	unsigned long flags;
+
+	spin_lock_irqsave(&tspi->reg_lock, flags);
+	if (tspi->clk_state < 1)
 		BUG();
 	writel(val, tspi->base + reg);
 
 	/* Synchronize write by reading back the register */
 	readl(tspi->base + SLINK_MAS_DATA);
+	spin_unlock_irqrestore(&tspi->reg_lock, flags);
 }
 
+static int tegra_spi_clk_disable(struct spi_tegra_data *tspi)
+{
+	unsigned long flags;
+
+	/* Flush all write which are in PPSB queue by reading back */
+	spi_tegra_readl(tspi, SLINK_MAS_DATA);
+
+	spin_lock_irqsave(&tspi->reg_lock, flags);
+	tspi->clk_state--;
+	spin_unlock_irqrestore(&tspi->reg_lock, flags);
+	clk_disable(tspi->clk);
+	clk_disable(tspi->sclk);
+	return 0;
+}
+
+static int tegra_spi_clk_enable(struct spi_tegra_data *tspi)
+{
+	unsigned long flags;
+
+	clk_enable(tspi->sclk);
+	clk_enable(tspi->clk);
+	spin_lock_irqsave(&tspi->reg_lock, flags);
+	tspi->clk_state++;
+	spin_unlock_irqrestore(&tspi->reg_lock, flags);
+	return 0;
+}
+
+#if SPI_PM_RUNTIME_ENABLE
+#define spi_pm_runtime_get_sync(dev) pm_runtime_get_sync(dev)
+#define spi_pm_runtime_put_sync(dev) pm_runtime_put_sync(dev)
+#define spi_pm_runtime_enable(dev) pm_runtime_enable(dev)
+#define spi_pm_runtime_disable(dev) pm_runtime_disable(dev)
+#define spi_pm_runtime_enabled(dev) pm_runtime_enabled(dev)
+#define spi_pm_runtime_status_suspended(dev) pm_runtime_status_suspended(dev)
+#else
+#define spi_pm_runtime_get_sync(dev) tegra_spi_runtime_resume(dev)
+#define spi_pm_runtime_put_sync(dev) tegra_spi_runtime_idle(dev)
+#define spi_pm_runtime_enable(dev) do { } while(0)
+#define spi_pm_runtime_disable(dev) do { } while(0)
+#define spi_pm_runtime_enabled(dev) true
+#define spi_pm_runtime_status_suspended(dev) true
+#endif
+
 static void cancel_dma(struct tegra_dma_channel *dma_chan,
 	struct tegra_dma_req *req)
 {
@@ -738,9 +794,9 @@ static void spi_tegra_start_transfer(struct spi_device *spi,
 
 	command2 = tspi->def_command2_reg;
 	if (is_first_of_msg) {
-		if ((ret = pm_runtime_get_sync(&tspi->pdev->dev)) < 0) {
+		if ((ret = spi_pm_runtime_get_sync(&tspi->pdev->dev)) < 0) {
 			dev_err(&tspi->pdev->dev,
-				"%s: pm_runtime_get_sync() returns %d\n",
+				"%s: spi_pm_runtime_get_sync() returns %d\n",
 				__func__, ret);
 			return;
 		}
@@ -855,7 +911,7 @@ static int spi_tegra_setup(struct spi_device *spi)
 		return -EINVAL;
 	}
 
-	pm_runtime_get_sync(&tspi->pdev->dev);
+	spi_pm_runtime_get_sync(&tspi->pdev->dev);
 
 	spin_lock_irqsave(&tspi->lock, flags);
 	val = tspi->def_command_reg;
@@ -867,7 +923,7 @@ static int spi_tegra_setup(struct spi_device *spi)
 	spi_tegra_writel(tspi, tspi->def_command_reg, SLINK_COMMAND);
 	spin_unlock_irqrestore(&tspi->lock, flags);
 
-	pm_runtime_put_sync(&tspi->pdev->dev);
+	spi_pm_runtime_put_sync(&tspi->pdev->dev);
 	return 0;
 }
 
@@ -1017,7 +1073,7 @@ static void spi_tegra_curr_transfer_complete(struct spi_tegra_data *tspi,
 			/* Provide delay to stablize the signal state */
 			spin_unlock_irqrestore(&tspi->lock, *irq_flags);
 			udelay(10);
-			pm_runtime_put_sync(&tspi->pdev->dev);
+			spi_pm_runtime_put_sync(&tspi->pdev->dev);
 			spin_lock_irqsave(&tspi->lock, *irq_flags);
 			tspi->is_transfer_in_progress = false;
 			/* Check if any new request has come between
@@ -1317,6 +1373,7 @@ static int __init spi_tegra_probe(struct platform_device *pdev)
 	tspi->is_transfer_in_progress = false;
 	tspi->is_suspended = false;
 	spin_lock_init(&tspi->lock);
+	spin_lock_init(&tspi->reg_lock);
 
 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!r) {
@@ -1422,8 +1479,8 @@ static int __init spi_tegra_probe(struct platform_device *pdev)
 	tspi->def_command2_reg = SLINK_CS_ACTIVE_BETWEEN;
 
 skip_dma_alloc:
-	pm_runtime_enable(&pdev->dev);
-	if (!pm_runtime_enabled(&pdev->dev)) {
+	spi_pm_runtime_enable(&pdev->dev);
+	if (!spi_pm_runtime_enabled(&pdev->dev)) {
 		ret = tegra_spi_runtime_resume(&pdev->dev);
 		if (ret) {
 			dev_err(&pdev->dev, "runtime resume failed %d", ret);
@@ -1433,7 +1490,7 @@ skip_dma_alloc:
 
 	/* Enable clock if it is require to be enable always */
 	if (tspi->is_clkon_always)
-		pm_runtime_get_sync(&pdev->dev);
+		spi_pm_runtime_get_sync(&pdev->dev);
 
 	master->dev.of_node = pdev->dev.of_node;
 	ret = spi_register_master(master);
@@ -1459,14 +1516,14 @@ exit_master_unregister:
 	spi_unregister_master(master);
 
 	if (tspi->is_clkon_always)
-		pm_runtime_put_sync(&pdev->dev);
+		spi_pm_runtime_put_sync(&pdev->dev);
 
 exit_pm_suspend:
-	if (!pm_runtime_status_suspended(&pdev->dev))
+	if (!spi_pm_runtime_status_suspended(&pdev->dev))
 		tegra_spi_runtime_idle(&pdev->dev);
 
 exit_pm_disable:
-	pm_runtime_disable(&pdev->dev);
+	spi_pm_runtime_disable(&pdev->dev);
 
 	spi_tegra_deinit_dma_param(tspi, false);
 
@@ -1496,10 +1553,10 @@ static int __devexit spi_tegra_remove(struct platform_device *pdev)
 
 	/* Disable clock if it is always enabled */
 	if (tspi->is_clkon_always)
-		pm_runtime_put_sync(&pdev->dev);
+		spi_pm_runtime_put_sync(&pdev->dev);
 
-	pm_runtime_disable(&pdev->dev);
-	if (!pm_runtime_status_suspended(&pdev->dev))
+	spi_pm_runtime_disable(&pdev->dev);
+	if (!spi_pm_runtime_status_suspended(&pdev->dev))
 		tegra_spi_runtime_idle(&pdev->dev);
 
 	destroy_workqueue(tspi->spi_workqueue);
@@ -1555,7 +1612,7 @@ static int spi_tegra_suspend(struct device *dev)
 
 	/* Disable clock if it is always enabled */
 	if (tspi->is_clkon_always)
-		pm_runtime_put_sync(dev);
+		spi_pm_runtime_put_sync(dev);
 
 	return 0;
 }
@@ -1572,11 +1629,11 @@ static int spi_tegra_resume(struct device *dev)
 
 	/* Enable clock if it is always enabled */
 	if (tspi->is_clkon_always)
-		pm_runtime_get_sync(dev);
+		spi_pm_runtime_get_sync(dev);
 
-	pm_runtime_get_sync(dev);
+	spi_pm_runtime_get_sync(dev);
 	spi_tegra_writel(tspi, tspi->command_reg, SLINK_COMMAND);
-	pm_runtime_put_sync(dev);
+	spi_pm_runtime_put_sync(dev);
 
 	spin_lock_irqsave(&tspi->lock, flags);
 
@@ -1604,13 +1661,7 @@ static int tegra_spi_runtime_idle(struct device *dev)
 	struct spi_master *master = dev_get_drvdata(dev);
 	struct spi_tegra_data *tspi = spi_master_get_devdata(master);
 
-	/* Flush all write which are in PPSB queue by reading back */
-	spi_tegra_readl(tspi, SLINK_MAS_DATA);
-
-	tspi->clk_state = 0;
-	clk_disable(tspi->clk);
-	clk_disable(tspi->sclk);
-	return 0;
+	return tegra_spi_clk_disable(tspi);
 }
 
 static int tegra_spi_runtime_resume(struct device *dev)
@@ -1618,10 +1669,7 @@ static int tegra_spi_runtime_resume(struct device *dev)
 	struct spi_master *master = dev_get_drvdata(dev);
 	struct spi_tegra_data *tspi = spi_master_get_devdata(master);
 
-	clk_enable(tspi->sclk);
-	clk_enable(tspi->clk);
-	tspi->clk_state = 1;
-	return 0;
+	return tegra_spi_clk_enable(tspi);
 }
 
 static const struct dev_pm_ops tegra_spi_dev_pm_ops = {