Hi
some comments
On Fri, 1 Apr 2011, Avinash.H.M wrote:
> The i2c module has a special reset sequence. The sequence is
> - Disable the I2C.
> - Write to SOFTRESET bit.
> - Enable the I2C.
> - Poll on the RESETDONE bit.
> This sequence must be followed for i2c reset in omap2, omap3. The sequence is
> implemented as a function and the i2c_class is updated with the correct
> 'reset' pointer.
>
> Cc: Rajendra Nayak <rnayak@xxxxxx>
> Cc: Paul Walmsley <paul@xxxxxxxxx>
> Cc: Benoit Cousson <b-cousson@xxxxxx>
> Cc: Kevin Hilman <khilman@xxxxxx>
> Signed-off-by: Avinash.H.M <avinashhm@xxxxxx>
> ---
> arch/arm/mach-omap2/omap_hwmod.c | 59 ++++++++++++++++++++++++++
> arch/arm/mach-omap2/omap_hwmod_2420_data.c | 1 +
> arch/arm/mach-omap2/omap_hwmod_2430_data.c | 1 +
> arch/arm/mach-omap2/omap_hwmod_3xxx_data.c | 1 +
> arch/arm/plat-omap/include/plat/omap_hwmod.h | 2 +
> 5 files changed, 64 insertions(+), 0 deletions(-)
>
> diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c
> index e034294..f61c9c8 100644
> --- a/arch/arm/mach-omap2/omap_hwmod.c
> +++ b/arch/arm/mach-omap2/omap_hwmod.c
> @@ -156,6 +156,10 @@
> /* Name of the OMAP hwmod for the MPU */
> #define MPU_INITIATOR_NAME "mpu"
>
> +/* In register I2C_CON, Bit 15 is the I2C enable bit */
> +#define I2C_EN BIT(15)
> +#define I2C_CON_OFFSET 0x24
This stuff, along with omap_i2c_reset(), doesn't belong in omap_hwmod.c,
which is common code that is not I2C-specific. Please put it in
mach-omap2/i2c.c instead.
> +
> /* omap_hwmod_list contains all registered struct omap_hwmods */
> static LIST_HEAD(omap_hwmod_list);
>
> @@ -2369,3 +2373,58 @@ int omap_hwmod_no_setup_reset(struct omap_hwmod *oh)
>
> return 0;
> }
> +
> +/**
> + * omap_i2c_reset- reset the omap i2c module.
> + * @oh: struct omap_hwmod *
> + *
> + * The i2c moudle in omap2, omap3 had a special sequence to reset. The
> + * sequence is:
> + * - Disable the I2C.
> + * - Write to SOFTRESET bit.
> + * - Enable the I2C.
> + * - Poll on the RESETDONE bit.
> + * The sequence is implemented in below function. This is called for 2420,
> + * 2430 and omap3.
> + */
> +int omap_i2c_reset(struct omap_hwmod *oh)
> +{
> + u32 v = 0;
no need to initialize this to 0
> + int ret = 0, c = 0;
no need to initialize ret to 0
> +
> + /* Disable I2C */
> + v = omap_hwmod_read(oh, I2C_CON_OFFSET);
> + v = v & ~I2C_EN;
> + omap_hwmod_write(v, oh, I2C_CON_OFFSET);
> +
> + /* Write to the SOFTRESET bit */
> + v = oh->_sysc_cache;
> + ret = _set_softreset(oh, &v);
> + if (ret)
> + goto err1;
> + _write_sysconfig(v, oh);
> +
> + /* Enable I2C */
> + v = omap_hwmod_read(oh, I2C_CON_OFFSET);
> + v |= I2C_EN;
> + omap_hwmod_write(v, oh, I2C_CON_OFFSET);
> +
> + /* Poll on RESETDONE bit */
> + omap_test_timeout((omap_hwmod_read(oh,
> + oh->class->sysc->syss_offs)
> + & SYSS_RESETDONE_MASK),
> + MAX_MODULE_SOFTRESET_WAIT, c);
> +
> + if (c == MAX_MODULE_SOFTRESET_WAIT)
> + pr_warning("%s: %s: softreset failed (waited %d usec)\n",
> + __func__, oh->name, MAX_MODULE_SOFTRESET_WAIT);
> + else
> + pr_debug("%s: %s: softreset in %d usec\n", __func__,
> + oh->name, c);
> +
> + return 0;
> +
> +err1:
> + pr_warning("%s: returned error from _set_softreset\n", __func__);
> + return ret;
> +}
> diff --git a/arch/arm/mach-omap2/omap_hwmod_2420_data.c b/arch/arm/mach-omap2/omap_hwmod_2420_data.c
> index 8eb3ce1..82ff5f7 100644
> --- a/arch/arm/mach-omap2/omap_hwmod_2420_data.c
> +++ b/arch/arm/mach-omap2/omap_hwmod_2420_data.c
> @@ -1447,6 +1447,7 @@ static struct omap_hwmod_class_sysconfig i2c_sysc = {
> static struct omap_hwmod_class i2c_class = {
> .name = "i2c",
> .sysc = &i2c_sysc,
> + .reset = &omap_i2c_reset,
> };
>
> static struct omap_i2c_dev_attr i2c_dev_attr;
> diff --git a/arch/arm/mach-omap2/omap_hwmod_2430_data.c b/arch/arm/mach-omap2/omap_hwmod_2430_data.c
> index a860fb5..ce292f0 100644
> --- a/arch/arm/mach-omap2/omap_hwmod_2430_data.c
> +++ b/arch/arm/mach-omap2/omap_hwmod_2430_data.c
> @@ -1524,6 +1524,7 @@ static struct omap_hwmod_class_sysconfig i2c_sysc = {
> static struct omap_hwmod_class i2c_class = {
> .name = "i2c",
> .sysc = &i2c_sysc,
> + .reset = &omap_i2c_reset,
> };
>
> static struct omap_i2c_dev_attr i2c_dev_attr = {
> diff --git a/arch/arm/mach-omap2/omap_hwmod_3xxx_data.c b/arch/arm/mach-omap2/omap_hwmod_3xxx_data.c
> index b98e2df..c74f972 100644
> --- a/arch/arm/mach-omap2/omap_hwmod_3xxx_data.c
> +++ b/arch/arm/mach-omap2/omap_hwmod_3xxx_data.c
> @@ -1460,6 +1460,7 @@ static struct omap_hwmod omap3xxx_uart4_hwmod = {
> static struct omap_hwmod_class i2c_class = {
> .name = "i2c",
> .sysc = &i2c_sysc,
> + .reset = &omap_i2c_reset,
> };
>
> /*
> diff --git a/arch/arm/plat-omap/include/plat/omap_hwmod.h b/arch/arm/plat-omap/include/plat/omap_hwmod.h
> index 1adea9c..26b7ad3 100644
> --- a/arch/arm/plat-omap/include/plat/omap_hwmod.h
> +++ b/arch/arm/plat-omap/include/plat/omap_hwmod.h
> @@ -545,6 +545,8 @@ struct omap_hwmod {
> };
>
> int omap_hwmod_register(struct omap_hwmod **ohs);
> +int omap_i2c_reset(struct omap_hwmod *oh);
This should go into plat-omap/include/plat/i2c.h
> +
> struct omap_hwmod *omap_hwmod_lookup(const char *name);
> int omap_hwmod_for_each(int (*fn)(struct omap_hwmod *oh, void *data),
> void *data);
> --
> 1.7.1
>
- Paul
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