The I2C driver for the MPC currently uses a fixed speed hard-coded into
the driver. This patch adds the FDT properties "fdr" and "dfsrr" for the
corresponding I2C registers to make the speed configurable via FDT,
e.g.:
[EMAIL PROTECTED] {
compatible = "fsl-i2c";
reg = <0x3100 0x100>;
interrupts = <43 2>;
interrupt-parent = <&mpic>;
dfsrr = <0x20>;
fdr = <0x03>;
};
Signed-off-by: Wolfgang Grandegger <[EMAIL PROTECTED]>
---
Documentation/powerpc/dts-bindings/fsl/i2c.txt | 9 +++--
drivers/i2c/busses/i2c-mpc.c | 45 ++++++++++++++++++++-----
2 files changed, 42 insertions(+), 12 deletions(-)
Index: linux-2.6-galak/drivers/i2c/busses/i2c-mpc.c
===================================================================
--- linux-2.6-galak.orig/drivers/i2c/busses/i2c-mpc.c
+++ linux-2.6-galak/drivers/i2c/busses/i2c-mpc.c
@@ -56,6 +56,8 @@ struct mpc_i2c {
struct i2c_adapter adap;
int irq;
u32 flags;
+ u32 fdr;
+ u32 dfsrr;
};
static __inline__ void writeccr(struct mpc_i2c *i2c, u32 x)
@@ -156,13 +158,16 @@ static int i2c_wait(struct mpc_i2c *i2c,
static void mpc_i2c_setclock(struct mpc_i2c *i2c)
{
/* Set clock and filters */
+ pr_debug("I2C: flags=%#x fdr=%#x dfsrr=%#x\n",
+ i2c->flags, i2c->fdr, i2c->dfsrr);
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);
+ writeb(i2c->fdr, i2c->base + MPC_I2C_FDR);
+ writeb(i2c->dfsrr, i2c->base + MPC_I2C_DFSRR);
+ } else if (i2c->flags & FSL_I2C_DEV_CLOCK_5200) {
+ writeb(i2c->fdr, i2c->base + MPC_I2C_FDR);
+ } else {
+ writel(i2c->fdr, i2c->base + MPC_I2C_FDR);
+ }
}
static void mpc_i2c_start(struct mpc_i2c *i2c)
@@ -320,18 +325,40 @@ static int __devinit fsl_i2c_probe(struc
{
int result = 0;
struct mpc_i2c *i2c;
+ const u32 *prop;
+ int prop_len;
i2c = kzalloc(sizeof(*i2c), GFP_KERNEL);
if (!i2c)
return -ENOMEM;
- if (of_get_property(op->node, "dfsrr", NULL))
- i2c->flags |= FSL_I2C_DEV_SEPARATE_DFSRR;
-
if (of_device_is_compatible(op->node, "fsl,mpc5200-i2c") ||
of_device_is_compatible(op->node, "mpc5200-i2c"))
i2c->flags |= FSL_I2C_DEV_CLOCK_5200;
+ prop = of_get_property(op->node, "dfsrr", &prop_len);
+ if (prop) {
+ i2c->flags |= FSL_I2C_DEV_SEPARATE_DFSRR;
+ if (prop_len == sizeof(*prop))
+ i2c->dfsrr = *prop;
+ else
+ /* Set resonable default value */
+ i2c->dfsrr = 0x10;
+ }
+
+ prop = of_get_property(op->node, "fdr", &prop_len);
+ if (prop && prop_len == sizeof(*prop)) {
+ i2c->fdr = *prop;
+ } else {
+ /* Set resonable default values */
+ if (i2c->flags & FSL_I2C_DEV_SEPARATE_DFSRR)
+ i2c->fdr = 0x31;
+ else if (i2c->flags & FSL_I2C_DEV_CLOCK_5200)
+ i2c->fdr = 0x3f;
+ else
+ i2c->fdr = 0x1031;
+ }
+
init_waitqueue_head(&i2c->queue);
i2c->base = of_iomap(op->node, 0);
Index: linux-2.6-galak/Documentation/powerpc/dts-bindings/fsl/i2c.txt
===================================================================
--- linux-2.6-galak.orig/Documentation/powerpc/dts-bindings/fsl/i2c.txt
+++ linux-2.6-galak/Documentation/powerpc/dts-bindings/fsl/i2c.txt
@@ -16,10 +16,12 @@ Recommended properties :
controller you have.
- interrupt-parent : the phandle for the interrupt controller that
services interrupts for this device.
- - dfsrr : boolean; if defined, indicates that this I2C device has
- a digital filter sampling rate register
- fsl5200-clocking : boolean; if defined, indicated that this device
uses the FSL 5200 clocking mechanism.
+ - dfsrr : boolean or <v>; if defined, indicates that this I2C device has
+ a digital filter sampling rate register. Optionally you can specify a
+ value v for the this register.
+ - fdr : <v>, if defined, the FDR register will be set to the value v.
Example :
[EMAIL PROTECTED] {
@@ -28,5 +30,6 @@ Example :
reg = <3000 18>;
device_type = "i2c";
compatible = "fsl-i2c";
- dfsrr;
+ fdr = <0x20>
+ dfsrr = <0x03>;
};
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