[PATCHV4 4/4] OMAP: I2C: I2C register restore only if context is lost
From: Shubhrajyoti D <hidden>
Date: 2011-07-21 15:23:38
Also in:
linux-i2c, linux-omap
Subsystem:
i2c subsystem, i2c subsystem host drivers, omap i2c driver, omap1 support, omap2+ support, the rest · Maintainers:
Andi Shyti, Vignesh R, Aaro Koskinen, Janusz Krzysztofik, Andreas Kemnade, Kevin Hilman, Roger Quadros, Tony Lindgren, Linus Torvalds
Currently i2c register restore is done always. Adding conditional restore. The i2c register restore is done only if the context is lost. Acked-by: Santosh Shilimkar <redacted> Signed-off-by: Shubhrajyoti D <redacted> --- drivers/i2c/busses/i2c-omap.c | 24 +++++++++++++++++------- 1 files changed, 17 insertions(+), 7 deletions(-)
diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index 75bb62d..dffdbfd 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c@@ -40,6 +40,7 @@ #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
@@ -200,6 +201,7 @@ struct omap_i2c_dev { u16 syscstate; u16 westate; u16 errata; + u32 dev_lost_count; }; const static u8 reg_map_ip_v1[] = {
@@ -260,6 +262,17 @@ static inline u16 omap_i2c_read_reg(struct omap_i2c_dev *i2c_dev, int reg) (i2c_dev->regs[reg] << i2c_dev->reg_shift)); } +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 void omap_i2c_unidle(struct omap_i2c_dev *dev) { struct platform_device *pdev;
@@ -273,13 +286,9 @@ static void omap_i2c_unidle(struct omap_i2c_dev *dev) pm_runtime_get_sync(&pdev->dev); if (pdata->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_WE_REG, dev->westate); - omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN); + u32 loss_cnt = omap_device_get_context_loss_count(pdev); + if (dev->dev_lost_count != loss_cnt) + omap_i2c_restore(dev); } dev->idle = 0;
@@ -318,6 +327,7 @@ static void omap_i2c_idle(struct omap_i2c_dev *dev) } dev->idle = 1; + dev->dev_lost_count = omap_device_get_context_loss_count(pdev); pm_runtime_put_sync(&pdev->dev); }
--
1.7.1