i2c: Blackfin I2C Driver: Functional power management support

PM_SUSPEND_MEM: Blackfin does not maintain register state through
Hibernate. Save and restore peripheral base initialization during
PM transitions.

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>

1 files changed, 24 insertions, 11 deletions

diff --git a/drivers/i2c/busses/i2c-bfin-twi.c b/drivers/i2c/busses/i2c-bfin-twi.c
index 48d084bdf7c8..3c855ff2992f 100644
--- a/drivers/i2c/busses/i2c-bfin-twi.c
+++ b/drivers/i2c/busses/i2c-bfin-twi.c
@@ -49,6 +49,8 @@ struct bfin_twi_iface {
         struct i2c_msg          *pmsg;
         int                     msg_num;
         int                     cur_msg;
+        u16                     saved_clkdiv;
+        u16                     saved_control;
         void __iomem            *regs_base;
 };
 
@@ -565,32 +567,43 @@ static u32 bfin_twi_functionality(struct i2c_adapter *adap)
                I2C_FUNC_I2C;
 }
 
-
 static struct i2c_algorithm bfin_twi_algorithm = {
         .master_xfer   = bfin_twi_master_xfer,
         .smbus_xfer    = bfin_twi_smbus_xfer,
         .functionality = bfin_twi_functionality,
 };
 
-
-static int i2c_bfin_twi_suspend(struct platform_device *dev, pm_message_t state)
+static int i2c_bfin_twi_suspend(struct platform_device *pdev, pm_message_t state)
 {
-        struct bfin_twi_iface *iface = platform_get_drvdata(dev);
+        struct bfin_twi_iface *iface = platform_get_drvdata(pdev);
+
+        iface->saved_clkdiv = read_CLKDIV(iface);
+        iface->saved_control = read_CONTROL(iface);
+
+        free_irq(iface->irq, iface);
 
         /* Disable TWI */
-        write_CONTROL(iface, read_CONTROL(iface) & ~TWI_ENA);
-        SSYNC();
+        write_CONTROL(iface, iface->saved_control & ~TWI_ENA);
 
         return 0;
 }
 
-static int i2c_bfin_twi_resume(struct platform_device *dev)
+static int i2c_bfin_twi_resume(struct platform_device *pdev)
 {
-        struct bfin_twi_iface *iface = platform_get_drvdata(dev);
+        struct bfin_twi_iface *iface = platform_get_drvdata(pdev);
 
-        /* Enable TWI */
-        write_CONTROL(iface, read_CONTROL(iface) | TWI_ENA);
-        SSYNC();
+        int rc = request_irq(iface->irq, bfin_twi_interrupt_entry,
+                IRQF_DISABLED, pdev->name, iface);
+        if (rc) {
+                dev_err(&pdev->dev, "Can't get IRQ %d !\n", iface->irq);
+                return -ENODEV;
+        }
+
+        /* Resume TWI interface clock as specified */
+        write_CLKDIV(iface, iface->saved_clkdiv);
+
+        /* Resume TWI */
+        write_CONTROL(iface, iface->saved_control);
 
         return 0;
 }