i2c-designware: Check component type register

Designware component type register is checked before attaching to the device.

Signed-off-by: Jean-Hugues Deschenes <jean-hugues.deschenes@octasic.com>
Signed-off-by: Dirk Brandewie <dirk.brandewie@gmail.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>

diff --git a/drivers/i2c/busses/i2c-designware.c b/drivers/i2c/busses/i2c-designware.c
index 28335c3717d9782ed774ee9c0685079cb8eeca36..49386951f7fdc81356d6493edc0488a8ffd50e87 100644 (file)
--- a/drivers/i2c/busses/i2c-designware.c
+++ b/drivers/i2c/busses/i2c-designware.c
@@ -69,6 +69,7 @@
 #define DW_IC_TXFLR            0x74
 #define DW_IC_RXFLR            0x78
 #define DW_IC_COMP_PARAM_1     0xf4
+#define DW_IC_COMP_TYPE                0xfc
 #define DW_IC_TX_ABRT_SOURCE   0x80
 
 #define DW_IC_CON_MASTER               0x1
@@ -710,6 +711,7 @@ static int __devinit dw_i2c_probe(struct platform_device *pdev)
        struct i2c_adapter *adap;
        struct resource *mem, *ioarea;
        int irq, r;
+       u32 reg;
 
        /* NOTE: driver uses the static register mapping */
        mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
@@ -756,12 +758,19 @@ static int __devinit dw_i2c_probe(struct platform_device *pdev)
                r = -EBUSY;
                goto err_unuse_clocks;
        }
-       {
-               u32 param1 = dw_readl(dev, DW_IC_COMP_PARAM_1);
 
-               dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1;
-               dev->rx_fifo_depth = ((param1 >> 8)  & 0xff) + 1;
+       reg = dw_readl(dev, DW_IC_COMP_TYPE);
+       if (reg != 0x44570140) {
+               dev_err(&pdev->dev, "Unknown Synopsys component type: "
+                               "0x%08x\n",     reg);
+               r = -ENODEV;
+               goto err_iounmap;
        }
+
+       reg = dw_readl(dev, DW_IC_COMP_PARAM_1);
+       dev->tx_fifo_depth = ((reg >> 16) & 0xff) + 1;
+       dev->rx_fifo_depth = ((reg >> 8)  & 0xff) + 1;
+
        i2c_dw_init(dev);
 
        dw_writel(dev, 0, DW_IC_INTR_MASK); /* disable IRQ */