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 <[email protected]> Cc: Paul Walmsley <[email protected]> Cc: Benoit Cousson <[email protected]> Cc: Kevin Hilman <[email protected]> Signed-off-by: Avinash.H.M <[email protected]> --- 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 + /* 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; + int ret = 0, c = 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); + 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 -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
