diff options
| author | Jean-Hugues Deschenes <jean-hugues.deschenes@octasic.com> | 2010-01-27 14:19:52 -0500 |
|---|---|---|
| committer | Ben Dooks <ben-linux@fluff.org> | 2010-02-03 02:35:59 +0000 |
| commit | 545eb087465eec1d656f766941a85d68189fee84 (patch) | |
| tree | e2a3077976a37fdb448a6528a7c0e74554e37542 /drivers/i2c | |
| parent | 3b1dc6496526f51974f9f41eb1056fa93ad79f56 (diff) | |
i2c-designware: Allow mixed endianness accesses
Allows CPUs of a given endianness to access a dw controller of a different
endianness. Endianncess difference is detected at run time through the dw
component type register.
Signed-off-by: Jean-Hugues Deschenes <jean-hugues.deschenes@octasic.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Diffstat (limited to 'drivers/i2c')
| -rw-r--r-- | drivers/i2c/busses/i2c-designware.c | 17 |
1 files changed, 15 insertions, 2 deletions
diff --git a/drivers/i2c/busses/i2c-designware.c b/drivers/i2c/busses/i2c-designware.c index 32f6232ba6af..8c2f64224a4a 100644 --- a/drivers/i2c/busses/i2c-designware.c +++ b/drivers/i2c/busses/i2c-designware.c @@ -36,6 +36,7 @@ #include <linux/interrupt.h> #include <linux/platform_device.h> #include <linux/io.h> +#include <linux/swab.h> /* * Registers offset @@ -192,6 +193,7 @@ static char *abort_sources[] = { * @status: i2c master status, one of STATUS_* * @abort_source: copy of the TX_ABRT_SOURCE register * @irq: interrupt number for the i2c master + * @swab: true if the instantiated IP is of different endianess * @adapter: i2c subsystem adapter node * @tx_fifo_depth: depth of the hardware tx fifo * @rx_fifo_depth: depth of the hardware rx fifo @@ -215,6 +217,7 @@ struct dw_i2c_dev { unsigned int status; u32 abort_source; int irq; + int swab; struct i2c_adapter adapter; unsigned int tx_fifo_depth; unsigned int rx_fifo_depth; @@ -222,11 +225,19 @@ struct dw_i2c_dev { static u32 dw_readl(struct dw_i2c_dev *dev, int offset) { - return readl(dev->base + offset); + u32 value = readl(dev->base + offset); + + if (dev->swab) + return swab32(value); + else + return value; } static void dw_writel(struct dw_i2c_dev *dev, u32 b, int offset) { + if (dev->swab) + b = swab32(b); + writel(b, dev->base + offset); } @@ -759,7 +770,9 @@ static int __devinit dw_i2c_probe(struct platform_device *pdev) } reg = dw_readl(dev, DW_IC_COMP_TYPE); - if (reg != 0x44570140) { + if (reg == ___constant_swab32(0x44570140)) + dev->swab = 1; + else if (reg != 0x44570140) { dev_err(&pdev->dev, "Unknown Synopsys component type: " "0x%08x\n", reg); r = -ENODEV; |