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>

diff --git a/drivers/i2c/busses/i2c-bfin-twi.c b/drivers/i2c/busses/i2c-bfin-twi.c
index 48d084b..3c855ff 100644 (file)
--- 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;
 }