When entering deep sleep, the value in the registers I2CFDR and
I2CDFSRR are lost. This causes I2C access to fail after resuming.
Add suspend/resume routines to save/restore the registers
I2CFDR and I2CDFSRR.
Signed-off-by: Zhao Chenhui <chenhui.zhao@xxxxxxxxxxxxx>
Signed-off-by: Li Yang <leoli@xxxxxxxxxxxxx>
---
drivers/i2c/busses/i2c-mpc.c | 30 ++++++++++++++++++++++++++++++
1 files changed, 30 insertions(+), 0 deletions(-)
diff --git a/drivers/i2c/busses/i2c-mpc.c b/drivers/i2c/busses/i2c-mpc.c
index a8ebb84..fb2627b 100644
--- a/drivers/i2c/busses/i2c-mpc.c
+++ b/drivers/i2c/busses/i2c-mpc.c
@@ -64,6 +64,9 @@ struct mpc_i2c {
struct i2c_adapter adap;
int irq;
u32 real_clk;
+#ifdef CONFIG_PM
+ u8 fdr, dfsrr;
+#endif
};
struct mpc_i2c_divider {
@@ -668,6 +671,30 @@ static int __devexit fsl_i2c_remove(struct platform_device *op)
return 0;
};
+#ifdef CONFIG_PM
+static int mpc_i2c_suspend(struct device *dev)
+{
+ struct mpc_i2c *i2c = dev_get_drvdata(dev);
+
+ i2c->fdr = readb(i2c->base + MPC_I2C_FDR);
+ i2c->dfsrr = readb(i2c->base + MPC_I2C_DFSRR);
+
+ return 0;
+}
+
+static int mpc_i2c_resume(struct device *dev)
+{
+ struct mpc_i2c *i2c = dev_get_drvdata(dev);
+
+ writeb(i2c->fdr, i2c->base + MPC_I2C_FDR);
+ writeb(i2c->dfsrr, i2c->base + MPC_I2C_DFSRR);
+
+ return 0;
+}
+
+SIMPLE_DEV_PM_OPS(mpc_i2c_pm_ops, mpc_i2c_suspend, mpc_i2c_resume);
+#endif
+
static struct mpc_i2c_data mpc_i2c_data_512x __devinitdata = {
.setup = mpc_i2c_setup_512x,
};
@@ -712,6 +739,9 @@ static struct platform_driver mpc_i2c_driver = {
.owner = THIS_MODULE,
.name = DRV_NAME,
.of_match_table = mpc_i2c_of_match,
+#ifdef CONFIG_PM
+ .pm = &mpc_i2c_pm_ops,
+#endif
},
};
--
1.6.4.1
--
To unsubscribe from this list: send the line "unsubscribe linux-i2c" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
