[PATCH 04/10] OMAP: I2C: I2C register restore only if context is lost

[Shubhrajyoti D]

 Currently i2c register restore is done always.
 Adding conditional restore.
 The i2c register restore is done only if the context is lost.
 Also remove the definition of SYSS_RESETDONE_MASK and use the
 one in omap_hwmod.h.

Cc: Kevin Hilman <khilman at ti.com>
Cc: Ben Dooks <ben-linux at fluff.org>
Acked-by: Santosh Shilimkar <santosh.shilimkar at ti.com> 
Signed-off-by: Shubhrajyoti D <shubhrajyoti at ti.com>
---
Previous discurssion
http://lists.infradead.org/pipermail/linux-arm-kernel/2011-July/058747.html

 drivers/i2c/busses/i2c-omap.c |   36 +++++++++++++++++++++++-------------
 1 files changed, 23 insertions(+), 13 deletions(-)

diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index f19bb7e..c07e3e4 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -43,6 +43,7 @@
 #include <linux/slab.h>
 #include <linux/i2c-omap.h>
 #include <linux/pm_runtime.h>
+#include <plat/omap_device.h>
 
 /* I2C controller revisions */
 #define OMAP_I2C_OMAP1_REV_2		0x20
@@ -157,9 +158,6 @@ enum {
 #define OMAP_I2C_SYSTEST_SDA_I		(1 << 1)	/* SDA line sense in */
 #define OMAP_I2C_SYSTEST_SDA_O		(1 << 0)	/* SDA line drive out */
 
-/* OCP_SYSSTATUS bit definitions */
-#define SYSS_RESETDONE_MASK		(1 << 0)
-
 /* OCP_SYSCONFIG bit definitions */
 #define SYSC_CLOCKACTIVITY_MASK		(0x3 << 8)
 #define SYSC_SIDLEMODE_MASK		(0x3 << 3)
@@ -206,6 +204,7 @@ struct omap_i2c_dev {
 	u16			syscstate;
 	u16			westate;
 	u16			errata;
+	int			dev_lost_count;
 };
 
 static const u8 reg_map_ip_v1[] = {
@@ -1151,12 +1150,24 @@ omap_i2c_remove(struct platform_device *pdev)
 }
 
 #ifdef CONFIG_PM_RUNTIME
+static void omap_i2c_restore(struct omap_i2c_dev *dev)
+{
+	omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
+	omap_i2c_write_reg(dev, OMAP_I2C_PSC_REG, dev->pscstate);
+	omap_i2c_write_reg(dev, OMAP_I2C_SCLL_REG, dev->scllstate);
+	omap_i2c_write_reg(dev, OMAP_I2C_SCLH_REG, dev->sclhstate);
+	omap_i2c_write_reg(dev, OMAP_I2C_BUF_REG, dev->bufstate);
+	omap_i2c_write_reg(dev, OMAP_I2C_WE_REG, dev->westate);
+	omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
+}
 static int omap_i2c_runtime_suspend(struct device *dev)
 {
 	struct platform_device *pdev = to_platform_device(dev);
 	struct omap_i2c_dev *_dev = platform_get_drvdata(pdev);
 	u16 iv;
 
+	_dev->dev_lost_count = omap_device_get_context_loss_count(pdev);
+
 	_dev->iestate = omap_i2c_read_reg(_dev, OMAP_I2C_IE_REG);
 	if (_dev->dtrev == OMAP_I2C_IP_VERSION_2)
 		omap_i2c_write_reg(_dev, OMAP_I2C_IP_V2_IRQENABLE_CLR, 1);
@@ -1180,16 +1191,15 @@ static int omap_i2c_runtime_resume(struct device *dev)
 	struct platform_device *pdev = to_platform_device(dev);
 	struct omap_i2c_dev *_dev = platform_get_drvdata(pdev);
 
-	if (_dev->flags & OMAP_I2C_FLAG_RESET_REGS_POSTIDLE) {
-		omap_i2c_write_reg(_dev, OMAP_I2C_CON_REG, 0);
-		omap_i2c_write_reg(_dev, OMAP_I2C_PSC_REG, _dev->pscstate);
-		omap_i2c_write_reg(_dev, OMAP_I2C_SCLL_REG, _dev->scllstate);
-		omap_i2c_write_reg(_dev, OMAP_I2C_SCLH_REG, _dev->sclhstate);
-		omap_i2c_write_reg(_dev, OMAP_I2C_BUF_REG, _dev->bufstate);
-		omap_i2c_write_reg(_dev, OMAP_I2C_SYSC_REG, _dev->syscstate);
-		omap_i2c_write_reg(_dev, OMAP_I2C_WE_REG, _dev->westate);
-		omap_i2c_write_reg(_dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
-	}
+	int loss_cnt = omap_device_get_context_loss_count(pdev);
+	if (loss_cnt < 0)
+		return loss_cnt;
+
+	if (_dev->dev_lost_count == loss_cnt && _dev->dev_lost_count)
+		return 0;
+
+	if (_dev->flags & OMAP_I2C_FLAG_RESET_REGS_POSTIDLE)
+		omap_i2c_restore(_dev);
 
 	/*
 	 * Don't write to this register if the IE state is 0 as it can
-- 
1.7.1