On Tue, Mar 31, 2009 at 6:37 AM, Wolfgang Grandegger [off-list ref] wr=
ote:

This patch makes the I2C bus speed configurable by using the I2C node
property "clock-frequency". If the property is not defined, the old
fixed clock settings will be used for backward comptibility.

The generic I2C clock properties, especially the CPU-specific source
clock pre-scaler are defined via the OF match table:

=A0static const struct of_device_id mpc_i2c_of_match[] =3D {
=A0 =A0 =A0 =A0{.compatible =3D "fsl,mpc5200b-i2c",
=A0 =A0 =A0 =A0 .data =3D (void *)FSL_I2C_DEV_CLOCK_5200, },
=A0 =A0 =A0 =A0{.compatible =3D "fsl,mpc5200-i2c",
=A0 =A0 =A0 =A0 .data =3D (void *)FSL_I2C_DEV_CLOCK_5200, },
=A0 =A0 =A0 =A0{.compatible =3D "fsl,mpc8313-i2c",
=A0 =A0 =A0 =A0 .data =3D (void *)FSL_I2C_DEV_SEPARATE_DFSRR, },
=A0 =A0 =A0 =A0{.compatible =3D "fsl,mpc8543-i2c",
=A0 =A0 =A0 =A0 .data =3D (void *)(FSL_I2C_DEV_SEPARATE_DFSRR |
=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0FSL_I2C_DEV_CLOCK_DIV2=

), },

=A0 =A0 =A0 =A0{.compatible =3D "fsl,mpc8544-i2c",
=A0 =A0 =A0 =A0 .data =3D (void *)(FSL_I2C_DEV_SEPARATE_DFSRR |
=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0FSL_I2C_DEV_CLOCK_DIV2=

3), },

=A0 =A0 =A0 =A0/* Backward compatibility */
=A0 =A0 =A0 =A0{.compatible =3D "fsl-i2c", },
=A0 =A0 =A0 =A0{},
=A0};

Instead passing in a flag (and using an ugly cast to do it) which is
then checked inside the mpc_i2c_setclock(), you should do this
instead:

struct fsl_i2c_match_data {
        int static void *(setclock)(struct device_node *node, struct
mpc_i2c *i2c, u32 clock);
        int flags;
        /* Other stuff can go here */
};

static const struct of_device_id mpc_i2c_of_match[] =3D {
        {.compatible =3D "fsl,mpc5200b-i2c",
         .data =3D (struct fsl_i2c_match_data[]) { .setclock =3D
mpc_i2c_setclock_mpc5200, },
        },
        {.compatible =3D "fsl,mpc5200-i2c",
         .data =3D (struct fsl_i2c_match_data[]) { .setclock =3D
mpc_i2c_setclock_mpc5200, },
        },
        {.compatible =3D "fsl,mpc8313-i2c",
         .data =3D (struct fsl_i2c_match_data[]) { .setclock =3D
mpc_i2c_setclock_separate_dfsrr, },
        },
        {.compatible =3D "fsl,mpc8543-i2c",
         .data =3D (struct fsl_i2c_match_data[]) { .setclock =3D
mpc_i2c_setclock_separate_dfsrr, },
         .flags =3D FSL_I2C_DEV_CLOCK_DIV2,
        },
        {.compatible =3D "fsl,mpc8544-i2c",
         .data =3D (struct fsl_i2c_match_data[]) { .setclock =3D
mpc_i2c_setclock_separate_dfsrr, },
         .flags =3D FSL_I2C_DEV_CLOCK_DIV23,
        },
        /* Backward compatibility */
        {.compatible =3D "fsl-i2c",
         .data =3D (struct fsl_i2c_match_data[]) { .setclock =3D
mpc_i2c_setclock, },
        },
        {},
  };

The table definition is more verbose this way, but I think it results
in more understandable and easier to extend code.  It also adds lets
the compiler do more type checking for you.


Also, this ...

1 13:25:08.000000000 +0200

31721011 +0200

+int fsl_i2c_get_fdr(struct device_node *node, u32 i2c_clock, u32 i2c_fla=

gs)

+{
[...]
+}
+EXPORT_SYMBOL(fsl_i2c_get_fdr);

... and this ...

1 13:25:08.000000000 +0200

9-03-31 13:28:54.309718526 +0200

+int fsl_i2c_get_fdr(struct device_node *node, u32 i2c_clock, u32 i2c_fla=

gs)

+{
[...]
+}
+EXPORT_SYMBOL(fsl_i2c_get_fdr);

does not work on a multiplatform kernel.  Both 8xxx and 52xx support
can be selected at the same time.

g.

--=20
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.