i2c: ocores: support big-endian register layout

This allows using OpenCores I2C controller attached to its host in
native-endian mode with bi-endian CPUs. Example of such system is Xtensa
XTFPGA platform.

Acked-by: Peter Korsgaard <peter@korsgaard.com>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

diff --git a/drivers/i2c/busses/i2c-ocores.c b/drivers/i2c/busses/i2c-ocores.c
index abf5db7e441ebab65fc7c8ad99b5f9bca6218b15..11b7b87311ed2ffb602dad86a31649bec0428dd8 100644 (file)
--- a/drivers/i2c/busses/i2c-ocores.c
+++ b/drivers/i2c/busses/i2c-ocores.c
@@ -92,6 +92,16 @@ static void oc_setreg_32(struct ocores_i2c *i2c, int reg, u8 value)
        iowrite32(value, i2c->base + (reg << i2c->reg_shift));
 }
 
+static void oc_setreg_16be(struct ocores_i2c *i2c, int reg, u8 value)
+{
+       iowrite16be(value, i2c->base + (reg << i2c->reg_shift));
+}
+
+static void oc_setreg_32be(struct ocores_i2c *i2c, int reg, u8 value)
+{
+       iowrite32be(value, i2c->base + (reg << i2c->reg_shift));
+}
+
 static inline u8 oc_getreg_8(struct ocores_i2c *i2c, int reg)
 {
        return ioread8(i2c->base + (reg << i2c->reg_shift));
@@ -107,6 +117,16 @@ static inline u8 oc_getreg_32(struct ocores_i2c *i2c, int reg)
        return ioread32(i2c->base + (reg << i2c->reg_shift));
 }
 
+static inline u8 oc_getreg_16be(struct ocores_i2c *i2c, int reg)
+{
+       return ioread16be(i2c->base + (reg << i2c->reg_shift));
+}
+
+static inline u8 oc_getreg_32be(struct ocores_i2c *i2c, int reg)
+{
+       return ioread32be(i2c->base + (reg << i2c->reg_shift));
+}
+
 static inline void oc_setreg(struct ocores_i2c *i2c, int reg, u8 value)
 {
        i2c->setreg(i2c, reg, value);
@@ -428,6 +448,9 @@ static int ocores_i2c_probe(struct platform_device *pdev)
                i2c->reg_io_width = 1; /* Set to default value */
 
        if (!i2c->setreg || !i2c->getreg) {
+               bool be = pdata ? pdata->big_endian :
+                       of_device_is_big_endian(pdev->dev.of_node);
+
                switch (i2c->reg_io_width) {
                case 1:
                        i2c->setreg = oc_setreg_8;
@@ -435,13 +458,13 @@ static int ocores_i2c_probe(struct platform_device *pdev)
                        break;
 
                case 2:
-                       i2c->setreg = oc_setreg_16;
-                       i2c->getreg = oc_getreg_16;
+                       i2c->setreg = be ? oc_setreg_16be : oc_setreg_16;
+                       i2c->getreg = be ? oc_getreg_16be : oc_getreg_16;
                        break;
 
                case 4:
-                       i2c->setreg = oc_setreg_32;
-                       i2c->getreg = oc_getreg_32;
+                       i2c->setreg = be ? oc_setreg_32be : oc_setreg_32;
+                       i2c->getreg = be ? oc_getreg_32be : oc_getreg_32;
                        break;
 
                default:

diff --git a/include/linux/i2c-ocores.h b/include/linux/i2c-ocores.h
index 1c06b5c7c308468204e53883398c11d29d12539a..01edd96fe1f76a3a1ccc06c49f49e2f0a6f3ce4a 100644 (file)
--- a/include/linux/i2c-ocores.h
+++ b/include/linux/i2c-ocores.h
@@ -15,6 +15,7 @@ struct ocores_i2c_platform_data {
        u32 reg_shift; /* register offset shift value */
        u32 reg_io_width; /* register io read/write width */
        u32 clock_khz; /* input clock in kHz */
+       bool big_endian; /* registers are big endian */
        u8 num_devices; /* number of devices in the devices list */
        struct i2c_board_info const *devices; /* devices connected to the bus */
 };