On Wed, Apr 1, 2009 at 7:13 AM, Wolfgang Grandegger <w...@grandegger.com> wrote:
> 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 compatibility.
>
> The generic I2C clock properties, especially the CPU-specific source
> clock pre-scaler are defined via the OF match table:
>
> static const struct of_device_id mpc_i2c_of_match[] = {
> ...
> {.compatible = "fsl,mpc8543-i2c",
> .data = &(struct fsl_i2c_match_data) {
> .setclock = mpc_i2c_setclock_8xxx,
> .prescaler = 2,
> },
> },
>
> The "data" field defines the relevant I2C setclock function and the
> relevant prescaler for the I2C source clock frequency.
>
> It uses arch-specific tables and functions to determine resonable
> Freqency Divider Register (fdr) values for MPC83xx, MPC85xx, MPC86xx,
> MPC5200 and MPC5200B.
>
> The i2c->flags field and the corresponding FSL_I2C_DEV_* definitions
> have been removed as they are obsolete.
>
> Furthermore dev_dbg() and dev_info() are now used to profit from a more
> comprehensive output.
>
> Signed-off-by: Wolfgang Grandegger <w...@grandegger.com>
> arch/powerpc/include/asm/mpc52xx.h | 11 +
> arch/powerpc/platforms/52xx/mpc52xx_common.c | 57 ++++++++++
> arch/powerpc/sysdev/fsl_soc.c | 90 ++++++++++++++++
> arch/powerpc/sysdev/fsl_soc.h | 12 ++
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
I mostly like this patch. However, as I mentioned in my other reply,
I'm going to NAK it because the divisor tables are not common code and
do not belong in common code files.
Other than that, I like this version of the patch and I think it is
almost finished. More comments below.
> -static void mpc_i2c_setclock(struct mpc_i2c *i2c)
> -{
> - /* Set clock and filters */
> - if (i2c->flags & FSL_I2C_DEV_SEPARATE_DFSRR) {
> - writeb(0x31, i2c->base + MPC_I2C_FDR);
> - writeb(0x10, i2c->base + MPC_I2C_DFSRR);
> - } else if (i2c->flags & FSL_I2C_DEV_CLOCK_5200)
> - writeb(0x3f, i2c->base + MPC_I2C_FDR);
> - else
> - writel(0x1031, i2c->base + MPC_I2C_FDR);
> +static void mpc_i2c_setclock_52xx(struct device_node *node,
> + struct mpc_i2c *i2c,
> + u32 clock, u32 prescaler)
> +{
> + int fdr = mpc52xx_i2c_get_fdr(node, clock, prescaler);
> +
> + if (fdr < 0)
> + fdr = 0x3f; /* backward compatibility */
> + writeb(fdr & 0xff, i2c->base + MPC_I2C_FDR);
> + dev_info(i2c->dev, "clock %d Hz (fdr=%d)\n", clock, fdr);
> +}
> +
> +static void mpc_i2c_setclock_8xxx(struct device_node *node,
> + struct mpc_i2c *i2c,
> + u32 clock, u32 prescaler)
> +{
> + int fdr = fsl_i2c_get_fdr(node, clock, prescaler);
> +
> + if (fdr < 0)
> + fdr = 0x1031; /* backward compatibility */
> + writeb(fdr & 0xff, i2c->base + MPC_I2C_FDR);
> + writeb((fdr >> 8) & 0xff, i2c->base + MPC_I2C_DFSRR);
> + dev_info(i2c->dev, "clock %d Hz (dfsrr=%d fdr=%d)\n",
> + clock, fdr >> 8, fdr & 0xff);
> }
Very neat and tidy indeed. I like this.
> Index: linux-2.6/arch/powerpc/sysdev/fsl_soc.c
> ===================================================================
> --- linux-2.6.orig/arch/powerpc/sysdev/fsl_soc.c 2009-03-31
> 21:27:52.000000000 +0200
> +++ linux-2.6/arch/powerpc/sysdev/fsl_soc.c 2009-04-01 12:09:18.796719327
> +0200
> @@ -39,7 +39,7 @@
> #include <sysdev/fsl_soc.h>
> #include <mm/mmu_decl.h>
> #include <asm/cpm2.h>
> -
> +#define DEBUG
^^^^^^^^^^^^^^^^^^^^^^^ oops?
g.
--
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.
_______________________________________________
Linuxppc-dev mailing list
Linuxppc-dev@ozlabs.org
https://ozlabs.org/mailman/listinfo/linuxppc-dev
