FYI, This API is required for multiple DMA errata's which require putting DMA controller in no mstandby mode before stopping dma. The applicable errata's: 1. Errata ID: i557(Applicable for omap36xx all ES versions) The channel hangs when the Pause bit (DMA4_CDPi [7] ) is cleared through config port while in Standby. 2. Errata ID: i541(all omap2plus except omap4) sDMA FIFO draining does not finish Peter has posted patch for this errata https://patchwork.kernel.org/patch/224132/ 3. Errata ID: i88(only omap3430 ES1.0) Special programming model needed to disable DMA before end of block -Manjunath > -----Original Message----- > From: linux-omap-owner@xxxxxxxxxxxxxxx > [mailto:linux-omap-owner@xxxxxxxxxxxxxxx] On Behalf Of G, > Manjunath Kondaiah > Sent: Saturday, October 02, 2010 9:09 AM > To: linux-omap@xxxxxxxxxxxxxxx > Cc: Kevin Hilman; Paul Walmsley > Subject: [PATCH] OMAP2plus: PM: omap_device: API for set/get > MIDLE mode > > Certain errata's in OMAP2plus processors will require > disabling master standby mode before completing on going > operation. Without this, the results will be unpredictable. > Ex: OMAP3430 ES1.0(Errata ID:i88) will require DMA to be put > in no mstandby mode before disabling the channel after > completing the data transfer operation. > > Since current implementation of PM run time framework does > not support changing sysconfig settings during middle of the > on going operation, these API's will support the same. > > These API's should be used by device drivers only incase of > erratum applicable to their modules if there is no other > methods to resolve. > > Signed-off-by: G, Manjunath Kondaiah <manjugk@xxxxxx> > Cc: Kevin Hilman <khilman@xxxxxxxxxxxxxxxxxxx> > Cc: Paul Walmsley <paul@xxxxxxxxx> > --- > arch/arm/mach-omap2/omap_hwmod.c | 83 > ++++++++++++++++++++++++++ > arch/arm/plat-omap/include/plat/omap_hwmod.h | 3 + > arch/arm/plat-omap/omap_device.c | 36 +++++++++++ > 3 files changed, 122 insertions(+), 0 deletions(-) > > diff --git a/arch/arm/mach-omap2/omap_hwmod.c > b/arch/arm/mach-omap2/omap_hwmod.c > index 955861a..4f638fe 100644 > --- a/arch/arm/mach-omap2/omap_hwmod.c > +++ b/arch/arm/mach-omap2/omap_hwmod.c > @@ -250,6 +250,35 @@ static int > _set_master_standbymode(struct omap_hwmod *oh, u8 standbymode, } > > /** > + * _get_master_standbymode: get the OCP_SYSCONFIG MIDLEMODE field in > +@midlemode > + * @oh: struct omap_hwmod * > + * @standbymode: pointer to get mstandby mode bits(shifted to bit 0) > + * > + * Get the master standby mode bits in @midlemode for the @oh hwmod. > + * Does not fetch the data from the hardware instead returns value > + * from sysc_cache. Returns -EINVAL upon error or 0 upon success. > + */ > +static int _get_master_standbymode(struct omap_hwmod *oh, u32 > +*midlemode) { > + u32 mstandby_mask; > + u8 mstandby_shift; > + > + if (!oh->class->sysc || > + !(oh->class->sysc->sysc_flags & SYSC_HAS_MIDLEMODE)) > + return -EINVAL; > + > + if (!oh->class->sysc->sysc_fields) { > + WARN(1, "omap_hwmod: %s: offset struct for > sysconfig not" > + " provided in class\n", > oh->name); > + return -EINVAL; > + } > + > + *midlemode = ((oh->_sysc_cache) & mstandby_mask) >> > mstandby_shift; > + > + return 0; > +} > + > +/** > * _set_slave_idlemode: set the OCP_SYSCONFIG SIDLEMODE field in @v > * @oh: struct omap_hwmod * > * @idlemode: SIDLEMODE field bits > @@ -1421,6 +1450,60 @@ int > omap_hwmod_set_slave_idlemode(struct omap_hwmod *oh, u8 idlemode) } > > /** > + * omap_hwmod_set_master_idlemode - set the hwmod's OCP > master idlemode > + * @oh: struct omap_hwmod * > + * @idlemode: SIDLEMODE field bits (shifted to bit 0) > + * > + * Sets the IP block's OCP master idlemode in hardware, and > updates our > + * local copy. Intended to be used by drivers that have some erratum > + * that requires direct manipulation of the MIDLEMODE bits. Returns > + * -EINVAL if @oh is null, or passes along the return value from > + * _set_master_standbymode(). > + * > + * Any users of this function should be scrutinized carefully. > + */ > +int omap_hwmod_set_master_idlemode(struct omap_hwmod *oh, u8 > midlemode) > +{ > + u32 v; > + int retval = 0; > + > + if (!oh) > + return -EINVAL; > + > + v = oh->_sysc_cache; > + > + retval = _set_master_standbymode(oh, midlemode, &v); > + if (!retval) > + _write_sysconfig(v, oh); > + > + return retval; > +} > + > +/** > + * omap_hwmod_get_master_idlemode - set the hwmod's OCP > master idlemode > + * @oh: struct omap_hwmod * > + * @idlemode: pointer to get SIDLEMODE field bits (shifted to bit 0) > + * > + * Gets the IP block's OCP master idlemode from our local copy. > +Intended > + * to be used by drivers that have some erratum that requires direct > + * manipulation of the MIDLEMODE bits. Returns -EINVAL if > @oh is null, > + * or passes along the return value from _get_master_standbymode(). > + * > + * Any users of this function should be scrutinized carefully. > + */ > +int omap_hwmod_get_master_idlemode(struct omap_hwmod *oh, u32 > +*idlemode) { > + int retval = 0; > + > + if (!oh) > + return -EINVAL; > + > + retval = _get_master_standbymode(oh, idlemode); > + > + return retval; > +} > + > +/** > * omap_hwmod_register - register a struct omap_hwmod > * @oh: struct omap_hwmod * > * > diff --git a/arch/arm/plat-omap/include/plat/omap_hwmod.h > b/arch/arm/plat-omap/include/plat/omap_hwmod.h > index c1835af..13d5f0a 100644 > --- a/arch/arm/plat-omap/include/plat/omap_hwmod.h > +++ b/arch/arm/plat-omap/include/plat/omap_hwmod.h > @@ -524,6 +524,9 @@ int omap_hwmod_disable_clocks(struct > omap_hwmod *oh); > > int omap_hwmod_set_slave_idlemode(struct omap_hwmod *oh, u8 > idlemode); > > +int omap_hwmod_set_master_idlemode(struct omap_hwmod *oh, u8 > +midlemode); int omap_hwmod_get_master_idlemode(struct > omap_hwmod *oh, > +u32 *idlemode); > + > int omap_hwmod_reset(struct omap_hwmod *oh); void > omap_hwmod_ocp_barrier(struct omap_hwmod *oh); > > diff --git a/arch/arm/plat-omap/omap_device.c > b/arch/arm/plat-omap/omap_device.c > index abe933c..d782314 100644 > --- a/arch/arm/plat-omap/omap_device.c > +++ b/arch/arm/plat-omap/omap_device.c > @@ -584,6 +584,42 @@ int omap_device_idle(struct > platform_device *pdev) } > > /** > + * omap_device_mstandby - set/get mstandby mode an omap_device > + * @od: struct omap_device * to idle > + * @midlemode: MIDLEMODE field bits (shifted to bit 0) > + * @set_mstandby: flag for mstandby get/set > + * > + * Sets/Gets the IP block's OCP master standby in hardware. Intended > + * to be used by drivers that have some erratum that requires direct > + * manipulation of the MSTANDBYMODE bits. Returns -EINVAL if the > + * omap_device is not currently enabled or passes along the return > +value > + * of > omap_hwmod_set_master_idlemode()/omap_hwmod_get_master_idlemode(). > + */ > +int omap_device_mstandby(struct platform_device *pdev, u8 *midlemode, > + bool set_mstandby) > +{ > + int ret, i; > + struct omap_device *od; > + struct omap_hwmod *oh; > + > + od = _find_by_pdev(pdev); > + if (od->_state != OMAP_DEVICE_STATE_ENABLED) { > + WARN(1, "omap_device: %s.%d: %s() called from > invalid state %d\n", > + od->pdev.name, od->pdev.id, __func__, od->_state); > + return -EINVAL; > + } > + > + oh = *od->hwmods; > + for (i = 0; i < od->hwmods_cnt; i++) { > + if (set_mstandby) > + ret = > omap_hwmod_set_master_idlemode(oh, *midlemode); > + else > + ret = > omap_hwmod_get_master_idlemode(oh, midlemode); > + } > + return ret; > +} > + > +/** > * omap_device_shutdown - shut down an omap_device > * @od: struct omap_device * to shut down > * > -- > 1.7.0.4 > > -- > To unsubscribe from this list: send the line "unsubscribe > linux-omap" in the body of a message to > majordomo@xxxxxxxxxxxxxxx More majordomo info at > http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
