Patch for I2C transmit overflow error

[linux-2.6-omap-h63xx.git] / drivers / i2c / busses / i2c-omap.c

diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index 55779f55ace5c0e8839a52265ccf26c410a1223a..3c4e5816156c6efd2f7b835421bb84ef1e00ea74 100644 (file)
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -160,7 +160,7 @@ static inline u16 omap_i2c_read_reg(struct omap_i2c_dev *i2c_dev, int reg)
        return __raw_readw(i2c_dev->base + reg);
 }
 
-static int omap_i2c_get_clocks(struct omap_i2c_dev *dev)
+static int __init omap_i2c_get_clocks(struct omap_i2c_dev *dev)
 {
        if (cpu_is_omap16xx() || cpu_class_is_omap2()) {
                dev->iclk = clk_get(dev->dev, "i2c_ick");
@@ -209,22 +209,28 @@ static void omap_i2c_unidle(struct omap_i2c_dev *dev)
        if (dev->iclk != NULL)
                clk_enable(dev->iclk);
        clk_enable(dev->fclk);
+       dev->idle = 0;
        if (dev->iestate)
                omap_i2c_write_reg(dev, OMAP_I2C_IE_REG, dev->iestate);
-       dev->idle = 0;
 }
 
 static void omap_i2c_idle(struct omap_i2c_dev *dev)
 {
        u16 iv;
 
-       dev->idle = 1;
        dev->iestate = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG);
        omap_i2c_write_reg(dev, OMAP_I2C_IE_REG, 0);
        if (dev->rev1)
                iv = omap_i2c_read_reg(dev, OMAP_I2C_IV_REG);
        else
                omap_i2c_write_reg(dev, OMAP_I2C_STAT_REG, dev->iestate);
+       /*
+        * The wmb() is to ensure that the I2C interrupt mask write
+        * reaches the I2C controller before the dev->idle store
+        * occurs.
+        */
+       wmb();
+       dev->idle = 1;
        clk_disable(dev->fclk);
        if (dev->iclk != NULL)
                clk_disable(dev->iclk);
@@ -529,6 +535,9 @@ omap_i2c_ack_stat(struct omap_i2c_dev *dev, u16 stat)
        omap_i2c_write_reg(dev, OMAP_I2C_STAT_REG, stat);
 }
 
+/* rev1 devices are apparently only on some 15xx */
+#ifdef CONFIG_ARCH_OMAP15XX
+
 static irqreturn_t
 omap_i2c_rev1_isr(int this_irq, void *dev_id)
 {
@@ -583,6 +592,9 @@ omap_i2c_rev1_isr(int this_irq, void *dev_id)
 
        return IRQ_HANDLED;
 }
+#else
+#define omap_i2c_rev1_isr              0
+#endif
 
 static irqreturn_t
 omap_i2c_isr(int this_irq, void *dev_id)
@@ -649,6 +661,7 @@ omap_i2c_isr(int this_irq, void *dev_id)
                                }
                        }
                        omap_i2c_ack_stat(dev, stat & (OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR));
+                       continue;
                }
                if (stat & (OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR)) {
                        u8 num_bytes = 1;
@@ -682,13 +695,14 @@ omap_i2c_isr(int this_irq, void *dev_id)
                                omap_i2c_write_reg(dev, OMAP_I2C_DATA_REG, w);
                        }
                        omap_i2c_ack_stat(dev, stat & (OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR));
+                       continue;
                }
                if (stat & OMAP_I2C_STAT_ROVR) {
                        dev_err(dev->dev, "Receive overrun\n");
                        dev->cmd_err |= OMAP_I2C_STAT_ROVR;
                }
                if (stat & OMAP_I2C_STAT_XUDF) {
-                       dev_err(dev->dev, "Transmit overflow\n");
+                       dev_err(dev->dev, "Transmit underflow\n");
                        dev->cmd_err |= OMAP_I2C_STAT_XUDF;
                }
        }
@@ -701,7 +715,7 @@ static const struct i2c_algorithm omap_i2c_algo = {
        .functionality  = omap_i2c_func,
 };
 
-static int
+static int __init
 omap_i2c_probe(struct platform_device *pdev)
 {
        struct omap_i2c_dev     *dev;
@@ -844,14 +858,14 @@ static struct platform_driver omap_i2c_driver = {
 };
 
 /* I2C may be needed to bring up other drivers */
-static int __init
+static int __devinit
 omap_i2c_init_driver(void)
 {
        return platform_driver_register(&omap_i2c_driver);
 }
 subsys_initcall(omap_i2c_init_driver);
 
-static void __exit omap_i2c_exit_driver(void)
+static void __devexit omap_i2c_exit_driver(void)
 {
        platform_driver_unregister(&omap_i2c_driver);
 }