| Message ID | 1311935813-8481-2-git-send-email-shubhrajyoti@ti.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Shubhrajyoti D <shubhrajyoti@ti.com> writes: > Under some error conditions the i2c driver may do a reset. ^ ^ minor: extra whitespace > Adding a reset field and support in the platform. s/platform/device-specific code/ > Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com> That being said, omap_device_shutdown() should already do a clean shutdown + reset for you, and i2c-omap.h already has a pointer for ->device_shutdown() so a new device_reset() should not be needed. IOW, simply adding pdata->device_shutdown = omap_device_shutdown() should work. Kevin > --- > arch/arm/plat-omap/i2c.c | 18 ++++++++++++++++++ > include/linux/i2c-omap.h | 1 + > 2 files changed, 19 insertions(+), 0 deletions(-) > > diff --git a/arch/arm/plat-omap/i2c.c b/arch/arm/plat-omap/i2c.c > index 2388b8e..be36cac 100644 > --- a/arch/arm/plat-omap/i2c.c > +++ b/arch/arm/plat-omap/i2c.c > @@ -146,6 +146,22 @@ static struct omap_device_pm_latency omap_i2c_latency[] = { > .flags = OMAP_DEVICE_LATENCY_AUTO_ADJUST, > }, > }; > +/** > + * omap2_i2c_reset - reset the omap i2c module. > + * @dev: struct device* > + */ > + > +static int omap2_i2c_reset(struct device *dev) > +{ > + int r = 0; > + struct platform_device *pdev = to_platform_device(dev); > + struct omap_device *odev = to_omap_device(pdev); > + struct omap_hwmod *oh; > + > + oh = odev->hwmods[0]; > + r = omap_hwmod_reset(oh); > + return r; > +} > > static inline int omap2_i2c_add_bus(int bus_id) > { > @@ -187,6 +203,8 @@ static inline int omap2_i2c_add_bus(int bus_id) > */ > if (cpu_is_omap34xx()) > pdata->set_mpu_wkup_lat = omap_pm_set_max_mpu_wakeup_lat_compat; > + > + pdata->device_reset = omap2_i2c_reset; > od = omap_device_build(name, bus_id, oh, pdata, > sizeof(struct omap_i2c_bus_platform_data), > omap_i2c_latency, ARRAY_SIZE(omap_i2c_latency), 0); > diff --git a/include/linux/i2c-omap.h b/include/linux/i2c-omap.h > index 98ae49b..8aa91b6 100644 > --- a/include/linux/i2c-omap.h > +++ b/include/linux/i2c-omap.h > @@ -38,6 +38,7 @@ struct omap_i2c_bus_platform_data { > int (*device_enable) (struct platform_device *pdev); > int (*device_shutdown) (struct platform_device *pdev); > int (*device_idle) (struct platform_device *pdev); > + int (*device_reset) (struct device *dev); > }; > > #endif
On Wednesday 03 August 2011 04:53 AM, Kevin Hilman wrote: > Shubhrajyoti D<shubhrajyoti@ti.com> writes: > >> Under some error conditions the i2c driver may do a reset. > ^ ^ > minor: extra whitespace > >> Adding a reset field and support in the platform. > s/platform/device-specific code/ > Yes will fix these. >> Signed-off-by: Shubhrajyoti D<shubhrajyoti@ti.com> > That being said, omap_device_shutdown() should already do a clean > shutdown + reset for you, and i2c-omap.h already has a pointer for > ->device_shutdown() so a new device_reset() should not be needed. > > IOW, simply adding pdata->device_shutdown = omap_device_shutdown() > should work. i2C has a special reset sequence ie Disable -> reset -> enable -> Poll on reset done. This function is implemented in omap_i2c_reset. The omap_hwmod_reset calls -> _reset which calls ocp_softrest or custom reset if it is present.The latter is true for I2C. However I see that omap_device_shutdown -> _assert_hardreset However for I2c there doesnt seem to be a HW reset line. Am I missing something? > Kevin > >> --- >> arch/arm/plat-omap/i2c.c | 18 ++++++++++++++++++ >> include/linux/i2c-omap.h | 1 + >> 2 files changed, 19 insertions(+), 0 deletions(-) >> >> diff --git a/arch/arm/plat-omap/i2c.c b/arch/arm/plat-omap/i2c.c >> index 2388b8e..be36cac 100644 >> --- a/arch/arm/plat-omap/i2c.c >> +++ b/arch/arm/plat-omap/i2c.c >> @@ -146,6 +146,22 @@ static struct omap_device_pm_latency omap_i2c_latency[] = { >> .flags = OMAP_DEVICE_LATENCY_AUTO_ADJUST, >> }, >> }; >> +/** >> + * omap2_i2c_reset - reset the omap i2c module. >> + * @dev: struct device* >> + */ >> + >> +static int omap2_i2c_reset(struct device *dev) >> +{ >> + int r = 0; >> + struct platform_device *pdev = to_platform_device(dev); >> + struct omap_device *odev = to_omap_device(pdev); >> + struct omap_hwmod *oh; >> + >> + oh = odev->hwmods[0]; >> + r = omap_hwmod_reset(oh); >> + return r; >> +} >> >> static inline int omap2_i2c_add_bus(int bus_id) >> { >> @@ -187,6 +203,8 @@ static inline int omap2_i2c_add_bus(int bus_id) >> */ >> if (cpu_is_omap34xx()) >> pdata->set_mpu_wkup_lat = omap_pm_set_max_mpu_wakeup_lat_compat; >> + >> + pdata->device_reset = omap2_i2c_reset; >> od = omap_device_build(name, bus_id, oh, pdata, >> sizeof(struct omap_i2c_bus_platform_data), >> omap_i2c_latency, ARRAY_SIZE(omap_i2c_latency), 0); >> diff --git a/include/linux/i2c-omap.h b/include/linux/i2c-omap.h >> index 98ae49b..8aa91b6 100644 >> --- a/include/linux/i2c-omap.h >> +++ b/include/linux/i2c-omap.h >> @@ -38,6 +38,7 @@ struct omap_i2c_bus_platform_data { >> int (*device_enable) (struct platform_device *pdev); >> int (*device_shutdown) (struct platform_device *pdev); >> int (*device_idle) (struct platform_device *pdev); >> + int (*device_reset) (struct device *dev); >> }; >> >> #endif
Shubhrajyoti <shubhrajyoti@ti.com> writes: > On Wednesday 03 August 2011 04:53 AM, Kevin Hilman wrote: >> Shubhrajyoti D<shubhrajyoti@ti.com> writes: >> >>> Under some error conditions the i2c driver may do a reset. >> ^ ^ >> minor: extra whitespace >> >>> Adding a reset field and support in the platform. >> s/platform/device-specific code/ >> > Yes will fix these. >>> Signed-off-by: Shubhrajyoti D<shubhrajyoti@ti.com> >> That being said, omap_device_shutdown() should already do a clean >> shutdown + reset for you, and i2c-omap.h already has a pointer for >> ->device_shutdown() so a new device_reset() should not be needed. >> >> IOW, simply adding pdata->device_shutdown = omap_device_shutdown() >> should work. > i2C has a special reset sequence ie Disable -> reset -> enable -> Poll > on reset done. > This function is implemented in omap_i2c_reset. The > > omap_hwmod_reset calls -> _reset > > which calls ocp_softrest or custom reset if it is present.The latter > is true for I2C. > > However I see that > > omap_device_shutdown -> _assert_hardreset However for I2c there doesnt seem to be a HW reset line. > > > Am I missing something? > No, my fault. I thought omap_device_shutdown() also did soft reset, but I see that's not the case. You can ignore my comments about using omap_device_shutdown. Kevin
diff --git a/arch/arm/plat-omap/i2c.c b/arch/arm/plat-omap/i2c.c index 2388b8e..be36cac 100644 --- a/arch/arm/plat-omap/i2c.c +++ b/arch/arm/plat-omap/i2c.c @@ -146,6 +146,22 @@ static struct omap_device_pm_latency omap_i2c_latency[] = { .flags = OMAP_DEVICE_LATENCY_AUTO_ADJUST, }, }; +/** + * omap2_i2c_reset - reset the omap i2c module. + * @dev: struct device* + */ + +static int omap2_i2c_reset(struct device *dev) +{ + int r = 0; + struct platform_device *pdev = to_platform_device(dev); + struct omap_device *odev = to_omap_device(pdev); + struct omap_hwmod *oh; + + oh = odev->hwmods[0]; + r = omap_hwmod_reset(oh); + return r; +} static inline int omap2_i2c_add_bus(int bus_id) { @@ -187,6 +203,8 @@ static inline int omap2_i2c_add_bus(int bus_id) */ if (cpu_is_omap34xx()) pdata->set_mpu_wkup_lat = omap_pm_set_max_mpu_wakeup_lat_compat; + + pdata->device_reset = omap2_i2c_reset; od = omap_device_build(name, bus_id, oh, pdata, sizeof(struct omap_i2c_bus_platform_data), omap_i2c_latency, ARRAY_SIZE(omap_i2c_latency), 0); diff --git a/include/linux/i2c-omap.h b/include/linux/i2c-omap.h index 98ae49b..8aa91b6 100644 --- a/include/linux/i2c-omap.h +++ b/include/linux/i2c-omap.h @@ -38,6 +38,7 @@ struct omap_i2c_bus_platform_data { int (*device_enable) (struct platform_device *pdev); int (*device_shutdown) (struct platform_device *pdev); int (*device_idle) (struct platform_device *pdev); + int (*device_reset) (struct device *dev); }; #endif
Under some error conditions the i2c driver may do a reset. Adding a reset field and support in the platform. Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com> --- arch/arm/plat-omap/i2c.c | 18 ++++++++++++++++++ include/linux/i2c-omap.h | 1 + 2 files changed, 19 insertions(+), 0 deletions(-)