Re: [PATCH v4 0/7] Add TI EMIF SDRAM controller driver
Greg, On Monday 23 April 2012 08:14 PM, Shilimkar, Santosh wrote: On Mon, Apr 23, 2012 at 7:57 PM, Greg KH g...@kroah.com wrote: On Mon, Apr 23, 2012 at 04:34:46PM +0530, Shilimkar, Santosh wrote: Afzal, On Mon, Apr 23, 2012 at 4:26 PM, Mohammed, Afzal af...@ti.com wrote: Hi Aneesh, On Fri, Apr 13, 2012 at 01:28:55, V, Aneesh wrote: Thanks. I will wait for your review then. Once I have your comments I will re-work and submit in the new directory structure proposed. Do you have a plan on submitting EMIF driver in the new proposed (drivers/memory) directory. Or shall I submit GPMC driver by creating the new memory directory. Greg mentioned that he plans to do a review of EMIF driver. We were waiting for his comments before sending the updated series. No, don't wait for me, please resend, I was waiting for you :) Thanks Greg !! Will start working on updating the patch set and post it on list. Have posted the updated version [1] as per discussion on this thread. Regards Santosh [1] http://www.spinics.net/lists/arm-kernel/msg171869.html -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
RE: [PATCH v4 0/7] Add TI EMIF SDRAM controller driver
Hi Aneesh, On Fri, Apr 13, 2012 at 01:28:55, V, Aneesh wrote: Thanks. I will wait for your review then. Once I have your comments I will re-work and submit in the new directory structure proposed. Do you have a plan on submitting EMIF driver in the new proposed (drivers/memory) directory. Or shall I submit GPMC driver by creating the new memory directory. Regards Afzal -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH v4 0/7] Add TI EMIF SDRAM controller driver
Afzal, On Mon, Apr 23, 2012 at 4:26 PM, Mohammed, Afzal af...@ti.com wrote: Hi Aneesh, On Fri, Apr 13, 2012 at 01:28:55, V, Aneesh wrote: Thanks. I will wait for your review then. Once I have your comments I will re-work and submit in the new directory structure proposed. Do you have a plan on submitting EMIF driver in the new proposed (drivers/memory) directory. Or shall I submit GPMC driver by creating the new memory directory. Greg mentioned that he plans to do a review of EMIF driver. We were waiting for his comments before sending the updated series. Please go ahead in creating directory. Regards Santosh -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
RE: [PATCH v4 0/7] Add TI EMIF SDRAM controller driver
Hi Santosh, On Mon, Apr 23, 2012 at 16:34:46, Shilimkar, Santosh wrote: Please go ahead in creating directory. Thanks for the quick reply. Regards Afzal -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH v4 0/7] Add TI EMIF SDRAM controller driver
On Mon, Apr 23, 2012 at 04:34:46PM +0530, Shilimkar, Santosh wrote: Afzal, On Mon, Apr 23, 2012 at 4:26 PM, Mohammed, Afzal af...@ti.com wrote: Hi Aneesh, On Fri, Apr 13, 2012 at 01:28:55, V, Aneesh wrote: Thanks. I will wait for your review then. Once I have your comments I will re-work and submit in the new directory structure proposed. Do you have a plan on submitting EMIF driver in the new proposed (drivers/memory) directory. Or shall I submit GPMC driver by creating the new memory directory. Greg mentioned that he plans to do a review of EMIF driver. We were waiting for his comments before sending the updated series. No, don't wait for me, please resend, I was waiting for you :) -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH v4 0/7] Add TI EMIF SDRAM controller driver
On Mon, Apr 23, 2012 at 7:57 PM, Greg KH g...@kroah.com wrote: On Mon, Apr 23, 2012 at 04:34:46PM +0530, Shilimkar, Santosh wrote: Afzal, On Mon, Apr 23, 2012 at 4:26 PM, Mohammed, Afzal af...@ti.com wrote: Hi Aneesh, On Fri, Apr 13, 2012 at 01:28:55, V, Aneesh wrote: Thanks. I will wait for your review then. Once I have your comments I will re-work and submit in the new directory structure proposed. Do you have a plan on submitting EMIF driver in the new proposed (drivers/memory) directory. Or shall I submit GPMC driver by creating the new memory directory. Greg mentioned that he plans to do a review of EMIF driver. We were waiting for his comments before sending the updated series. No, don't wait for me, please resend, I was waiting for you :) Thanks Greg !! Will start working on updating the patch set and post it on list. Regards Santosh -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH v4 0/7] Add TI EMIF SDRAM controller driver
On Thu, Apr 12, 2012 at 08:50:55PM +0200, Cousson, Benoit wrote: + Felipe, Hi Paul, On 4/12/2012 7:00 PM, Paul Walmsley wrote: Hi On Thu, 12 Apr 2012, Mohammed, Afzal wrote: On Thu, Apr 12, 2012 at 18:40:45, Greg KH wrote: On Thu, Apr 12, 2012 at 12:17:49PM +0530, Santosh Shilimkar wrote: I was hoping that we will have some thing like drivers/memory/* but since it doesn't exist, we used drivers/misc. Why not create it? I have no objection to that, it makes it more obvious as to what this really is. There is another memory controller used in a few TI SoCs, namely GPMC [1], do you prefer having it too there. As of now it is not a driver, platform code handles GPMC, a patch series for converting it into a driver (but still residing in platform folder) was sent a few days back [2,3]. Probably the GPMC driver should go into a slightly different place than SDRC/EMIF. GPMC is actually a general-purpose parallel bus driver. It's used to interface Ethernet controllers, UARTs, FPGAs, NAND/NOR flash, SRAM, etc. It cannot be used to control DRAM, at least not without a separate DRAM controller chip. SDRC/EMIF are both DRAM controllers. That's all they do. They can't be used to control anything else. They implement DRAM refresh, etc. The LPDDR2 spec does consider as well NVM (Non Volatile Memory), so I think we should stick to driver/memory for EMIF. So perhaps something like drivers/memory/dram/ for the SDRAM controllers, and maybe drivers/memory/ for the GPMC? In fact Felipe was considering something else for that kind of general purpose bus driver like GMPC, C2C and LLI... ... But I do not remember the name :-) the name matters very little :-) But the idea was to avoid writing yet another bus driver and just use the platform_bus instead. We would do all the channel/port setup before hand and far-end device driver wouldn't have to know if it's integrated into the SoC or plugged though LLI/C2C/GPMC. From the driver's perspective it would look the same. -- balbi signature.asc Description: Digital signature
Re: [PATCH v4 0/7] Add TI EMIF SDRAM controller driver
On Wed, 2012-04-11 at 20:44 -0600, Paul Walmsley wrote: This is useful not only for OMAP4 and AM3517/3505, but also will probably be useful for the C6x chips that Mark Salter is working on. I have been keeping an occasional eye on these patches but I don't see any usefulness for the currently supported C6X chips. The current set of supported chips use a completely different DDR controller. There is an EMIF controller on some which provides a parallel bus for connecting to external devices (NOR flash, etc) but it looks completely different from the OMAP EMIF. I think the TI DaVinci chips have EMIF (and other IO blocks) similar to C6X which could use common drivers. --Mark -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH v4 0/7] Add TI EMIF SDRAM controller driver
On Thursday 12 April 2012 08:30 AM, Greg KH wrote: On Wed, Apr 11, 2012 at 08:44:39PM -0600, Paul Walmsley wrote: Cc Mark Greer, Mark Salter Hi Greg, Aneesh, On Sat, 17 Mar 2012, Aneesh V wrote: Add a driver for the EMIF SDRAM controller used in TI SoCs EMIF is an SDRAM controller that supports, based on its revision, one or more of LPDDR2/DDR2/DDR3 protocols.This driver adds support for LPDDR2. Just checking to see what the current state of this series is. Greg, are you considering this for merging, or are there remaining issues? Aneesh, do you have any remaining issues to resolve with this set? What about the review comment about devfreq? Devfreq is not suitable for this driver. I already replied on this thread [1] Acting on frequency change is just one function of the controller driver and that too need not bed to attached with devfreq. The driver has features like temperature handling as per JDEC specs, active power managements modes, system wide suspend power management like self refresh and also configuration which can help memory hotplug for power savings and initialising the DDR timings to avoid boot-loader defaults.The controller IP works in conjunction with PRCM (OMAP Power IP) block to achieve some of this functionality. I was hoping that we will have some thing like drivers/memory/* but since it doesn't exist, we used drivers/misc. Regards Santosh [1] https://lkml.org/lkml/2012/3/19/178 This is useful not only for OMAP4 and AM3517/3505, but also will probably be useful for the C6x chips that Mark Salter is working on. It's still in my to-review queue, that I'm slowly making my way through. So it's not lost, but I would like to get the devfreq interface question cleared up first. Let us know if you need more clarification on devfreq part. Thanks for looking into it. Regards Santosh -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH v4 0/7] Add TI EMIF SDRAM controller driver
On Thu, Apr 12, 2012 at 12:17:49PM +0530, Santosh Shilimkar wrote: I was hoping that we will have some thing like drivers/memory/* but since it doesn't exist, we used drivers/misc. Why not create it? I have no objection to that, it makes it more obvious as to what this really is. greg k-h -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
RE: [PATCH v4 0/7] Add TI EMIF SDRAM controller driver
Hi Greg, On Thu, Apr 12, 2012 at 18:40:45, Greg KH wrote: On Thu, Apr 12, 2012 at 12:17:49PM +0530, Santosh Shilimkar wrote: I was hoping that we will have some thing like drivers/memory/* but since it doesn't exist, we used drivers/misc. Why not create it? I have no objection to that, it makes it more obvious as to what this really is. There is another memory controller used in a few TI SoCs, namely GPMC [1], do you prefer having it too there. As of now it is not a driver, platform code handles GPMC, a patch series for converting it into a driver (but still residing in platform folder) was sent a few days back [2,3]. Regards Afzal [1] GPMC (General Purpose Memory Controller) in brief: GPMC is an unified memory controller dedicated to interfacing external memory devices like Asynchronous SRAM like memories and application specific integrated circuit devices. Asynchronous, synchronous, and page mode burst NOR flash devices NAND flash Pseudo-SRAM devices GPMC has to be configured as required by timings of the connected peripheral. It needs to be configured only initially. Once it is configured it can be used to handle different protocols like NAND, NOR. Various kinds of devices like ethernet, uart, usb, fpga etc can work using GPMC interface. GPMC has a seperate additional functionality of NAND handling [2] https://lkml.org/lkml/2012/4/5/210 [3] https://lkml.org/lkml/2012/4/5/212 -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH v4 0/7] Add TI EMIF SDRAM controller driver
On Thu, Apr 12, 2012 at 01:34:15PM +, Mohammed, Afzal wrote: Hi Greg, On Thu, Apr 12, 2012 at 18:40:45, Greg KH wrote: On Thu, Apr 12, 2012 at 12:17:49PM +0530, Santosh Shilimkar wrote: I was hoping that we will have some thing like drivers/memory/* but since it doesn't exist, we used drivers/misc. Why not create it? I have no objection to that, it makes it more obvious as to what this really is. There is another memory controller used in a few TI SoCs, namely GPMC [1], do you prefer having it too there. Sure, why not? As of now it is not a driver, platform code handles GPMC, a patch series for converting it into a driver (but still residing in platform folder) was sent a few days back [2,3]. People are moving things out of the platform folder, so drivers/memory makes sense. thanks, greg k-h -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
RE: [PATCH v4 0/7] Add TI EMIF SDRAM controller driver
Hi Greg, On Thu, Apr 12, 2012 at 19:40:50, Greg KH wrote: There is another memory controller used in a few TI SoCs, namely GPMC [1], do you prefer having it too there. Sure, why not? Thanks a lot, we were struggling to find a suitable location for the driver. Regards Afzal -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH v4 0/7] Add TI EMIF SDRAM controller driver
On Thu, Apr 12, 2012 at 6:40 PM, Greg KH g...@kroah.com wrote: On Thu, Apr 12, 2012 at 12:17:49PM +0530, Santosh Shilimkar wrote: I was hoping that we will have some thing like drivers/memory/* but since it doesn't exist, we used drivers/misc. Why not create it? I have no objection to that, it makes it more obvious as to what this really is. Looks like I should have this question earlier. EMIF driver is perfect candidate for drivers/memory/ Thanks Greg for suggestion. We will go ahead and create drivers/memory and have EMIF drivers there. Regards Santosh -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH v4 0/7] Add TI EMIF SDRAM controller driver
Mohammed, Afzal af...@ti.com writes: Hi Greg, On Thu, Apr 12, 2012 at 18:40:45, Greg KH wrote: On Thu, Apr 12, 2012 at 12:17:49PM +0530, Santosh Shilimkar wrote: I was hoping that we will have some thing like drivers/memory/* but since it doesn't exist, we used drivers/misc. Why not create it? I have no objection to that, it makes it more obvious as to what this really is. There is another memory controller used in a few TI SoCs, namely GPMC [1], do you prefer having it too there. As of now it is not a driver, platform code handles GPMC, a patch series for converting it into a driver (but still residing in platform folder) was sent a few days back [2,3]. IMO, wherever EMIF ends up, GPMC should as well. Kevin [1] GPMC (General Purpose Memory Controller) in brief: GPMC is an unified memory controller dedicated to interfacing external memory devices like Asynchronous SRAM like memories and application specific integrated circuit devices. Asynchronous, synchronous, and page mode burst NOR flash devices NAND flash Pseudo-SRAM devices GPMC has to be configured as required by timings of the connected peripheral. It needs to be configured only initially. Once it is configured it can be used to handle different protocols like NAND, NOR. Various kinds of devices like ethernet, uart, usb, fpga etc can work using GPMC interface. GPMC has a seperate additional functionality of NAND handling [2] https://lkml.org/lkml/2012/4/5/210 [3] https://lkml.org/lkml/2012/4/5/212 -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org 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 majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
RE: [PATCH v4 0/7] Add TI EMIF SDRAM controller driver
Hi On Thu, 12 Apr 2012, Mohammed, Afzal wrote: On Thu, Apr 12, 2012 at 18:40:45, Greg KH wrote: On Thu, Apr 12, 2012 at 12:17:49PM +0530, Santosh Shilimkar wrote: I was hoping that we will have some thing like drivers/memory/* but since it doesn't exist, we used drivers/misc. Why not create it? I have no objection to that, it makes it more obvious as to what this really is. There is another memory controller used in a few TI SoCs, namely GPMC [1], do you prefer having it too there. As of now it is not a driver, platform code handles GPMC, a patch series for converting it into a driver (but still residing in platform folder) was sent a few days back [2,3]. Probably the GPMC driver should go into a slightly different place than SDRC/EMIF. GPMC is actually a general-purpose parallel bus driver. It's used to interface Ethernet controllers, UARTs, FPGAs, NAND/NOR flash, SRAM, etc. It cannot be used to control DRAM, at least not without a separate DRAM controller chip. SDRC/EMIF are both DRAM controllers. That's all they do. They can't be used to control anything else. They implement DRAM refresh, etc. So perhaps something like drivers/memory/dram/ for the SDRAM controllers, and maybe drivers/memory/ for the GPMC? - Paul -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH v4 0/7] Add TI EMIF SDRAM controller driver
+ Felipe, Hi Paul, On 4/12/2012 7:00 PM, Paul Walmsley wrote: Hi On Thu, 12 Apr 2012, Mohammed, Afzal wrote: On Thu, Apr 12, 2012 at 18:40:45, Greg KH wrote: On Thu, Apr 12, 2012 at 12:17:49PM +0530, Santosh Shilimkar wrote: I was hoping that we will have some thing like drivers/memory/* but since it doesn't exist, we used drivers/misc. Why not create it? I have no objection to that, it makes it more obvious as to what this really is. There is another memory controller used in a few TI SoCs, namely GPMC [1], do you prefer having it too there. As of now it is not a driver, platform code handles GPMC, a patch series for converting it into a driver (but still residing in platform folder) was sent a few days back [2,3]. Probably the GPMC driver should go into a slightly different place than SDRC/EMIF. GPMC is actually a general-purpose parallel bus driver. It's used to interface Ethernet controllers, UARTs, FPGAs, NAND/NOR flash, SRAM, etc. It cannot be used to control DRAM, at least not without a separate DRAM controller chip. SDRC/EMIF are both DRAM controllers. That's all they do. They can't be used to control anything else. They implement DRAM refresh, etc. The LPDDR2 spec does consider as well NVM (Non Volatile Memory), so I think we should stick to driver/memory for EMIF. So perhaps something like drivers/memory/dram/ for the SDRAM controllers, and maybe drivers/memory/ for the GPMC? In fact Felipe was considering something else for that kind of general purpose bus driver like GMPC, C2C and LLI... ... But I do not remember the name :-) Regards, Benoit -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH v4 0/7] Add TI EMIF SDRAM controller driver
Hi Benoît, On Thu, 12 Apr 2012, Cousson, Benoit wrote: The LPDDR2 spec does consider as well NVM (Non Volatile Memory), so I think we should stick to driver/memory for EMIF. Hmm good point! So perhaps something like drivers/memory/dram/ for the SDRAM controllers, and maybe drivers/memory/ for the GPMC? In fact Felipe was considering something else for that kind of general purpose bus driver like GMPC, C2C and LLI... ... But I do not remember the name :-) It would be nice if we could separate IP blocks that can drive an Ethernet controller or modem chip from the DRAM controllers; they are quite different beasts from a common API standpoint. - Paul
Re: [PATCH v4 0/7] Add TI EMIF SDRAM controller driver
On 4/12/2012 9:15 PM, Paul Walmsley wrote: Hi Benoît, On Thu, 12 Apr 2012, Cousson, Benoit wrote: The LPDDR2 spec does consider as well NVM (Non Volatile Memory), so I think we should stick to driver/memory for EMIF. Hmm good point! So perhaps something like drivers/memory/dram/ for the SDRAM controllers, and maybe drivers/memory/ for the GPMC? In fact Felipe was considering something else for that kind of general purpose bus driver like GMPC, C2C and LLI... ... But I do not remember the name :-) It would be nice if we could separate IP blocks that can drive an Ethernet controller or modem chip from the DRAM controllers; they are quite different beasts from a common API standpoint. Yep, fully agree. In fact Felipe's suggestion was something like drivers/ocd for off-chip devices, but maybe something like drivers/gpbus will highlight a little bit more the bus controller aspect of such driver. Regards, Benoit -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH v4 0/7] Add TI EMIF SDRAM controller driver
Hi Greg, On Wed, Apr 11, 2012 at 8:00 PM, Greg KH g...@kroah.com wrote: On Wed, Apr 11, 2012 at 08:44:39PM -0600, Paul Walmsley wrote: Cc Mark Greer, Mark Salter Hi Greg, Aneesh, On Sat, 17 Mar 2012, Aneesh V wrote: Add a driver for the EMIF SDRAM controller used in TI SoCs EMIF is an SDRAM controller that supports, based on its revision, one or more of LPDDR2/DDR2/DDR3 protocols.This driver adds support for LPDDR2. Just checking to see what the current state of this series is. Greg, are you considering this for merging, or are there remaining issues? Aneesh, do you have any remaining issues to resolve with this set? What about the review comment about devfreq? I see that Santosh has already commented on this. My views are similar, that frequency update is only one of the many functions of the driver. This is useful not only for OMAP4 and AM3517/3505, but also will probably be useful for the C6x chips that Mark Salter is working on. It's still in my to-review queue, that I'm slowly making my way through. So it's not lost, but I would like to get the devfreq interface question cleared up first. Thanks. I will wait for your review then. Once I have your comments I will re-work and submit in the new directory structure proposed. thanks, Aneesh -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH v4 0/7] Add TI EMIF SDRAM controller driver
Cc Mark Greer, Mark Salter Hi Greg, Aneesh, On Sat, 17 Mar 2012, Aneesh V wrote: Add a driver for the EMIF SDRAM controller used in TI SoCs EMIF is an SDRAM controller that supports, based on its revision, one or more of LPDDR2/DDR2/DDR3 protocols.This driver adds support for LPDDR2. Just checking to see what the current state of this series is. Greg, are you considering this for merging, or are there remaining issues? Aneesh, do you have any remaining issues to resolve with this set? This is useful not only for OMAP4 and AM3517/3505, but also will probably be useful for the C6x chips that Mark Salter is working on. - Paul -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH v4 0/7] Add TI EMIF SDRAM controller driver
Hi Paul, On 04/11/2012 07:44 PM, Paul Walmsley wrote: Cc Mark Greer, Mark Salter Hi Greg, Aneesh, On Sat, 17 Mar 2012, Aneesh V wrote: Add a driver for the EMIF SDRAM controller used in TI SoCs EMIF is an SDRAM controller that supports, based on its revision, one or more of LPDDR2/DDR2/DDR3 protocols.This driver adds support for LPDDR2. Just checking to see what the current state of this series is. Greg, are you considering this for merging, or are there remaining issues? Aneesh, do you have any remaining issues to resolve with this set? No. I don't have anything remaining. It's just that I was on vacation for a while and couldn't find time for this after that. If Greg is fine with this, I can rebase it and send one final version with Reviewed-By's from Santosh and Benoit. thanks, Aneesh -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH v4 0/7] Add TI EMIF SDRAM controller driver
On Wed, Apr 11, 2012 at 08:44:39PM -0600, Paul Walmsley wrote: Cc Mark Greer, Mark Salter Hi Greg, Aneesh, On Sat, 17 Mar 2012, Aneesh V wrote: Add a driver for the EMIF SDRAM controller used in TI SoCs EMIF is an SDRAM controller that supports, based on its revision, one or more of LPDDR2/DDR2/DDR3 protocols.This driver adds support for LPDDR2. Just checking to see what the current state of this series is. Greg, are you considering this for merging, or are there remaining issues? Aneesh, do you have any remaining issues to resolve with this set? What about the review comment about devfreq? This is useful not only for OMAP4 and AM3517/3505, but also will probably be useful for the C6x chips that Mark Salter is working on. It's still in my to-review queue, that I'm slowly making my way through. So it's not lost, but I would like to get the devfreq interface question cleared up first. thanks, greg k-h -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH v4 0/7] Add TI EMIF SDRAM controller driver
thanks for the response Greg, Hi Aneesh, On Wed, 11 Apr 2012, Greg KH wrote: On Wed, Apr 11, 2012 at 08:44:39PM -0600, Paul Walmsley wrote: On Sat, 17 Mar 2012, Aneesh V wrote: Add a driver for the EMIF SDRAM controller used in TI SoCs EMIF is an SDRAM controller that supports, based on its revision, one or more of LPDDR2/DDR2/DDR3 protocols.This driver adds support for LPDDR2. Just checking to see what the current state of this series is. Greg, are you considering this for merging, or are there remaining issues? Aneesh, do you have any remaining issues to resolve with this set? What about the review comment about devfreq? This is useful not only for OMAP4 and AM3517/3505, but also will probably be useful for the C6x chips that Mark Salter is working on. It's still in my to-review queue, that I'm slowly making my way through. So it's not lost, but I would like to get the devfreq interface question cleared up first. Aneesh, care to address the devfreq comments? I haven't looked at the series closely, so unfortunately I'm not presently in a position to comment. - Paul -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: Re: [PATCH v4 0/7] Add TI EMIF SDRAM controller driver
2012/3/19 함명주 myungjoo@samsung.com: Kyungmin Parkkmp...@infradead.org 2012-03-17 15:10 (GMT+09:00) Hi, On 3/17/12, Aneesh V wrote: Add a driver for the EMIF SDRAM controller used in TI SoCs EMIF is an SDRAM controller that supports, based on its revision, one or more of LPDDR2/DDR2/DDR3 protocols.This driver adds support for LPDDR2. The driver supports the following features: - Calculates the DDR AC timing parameters to be set in EMIF registers using data from the device data-sheets and based on the DDR frequency. If data from data-sheets is not available default timing values from the JEDEC spec are used. These will be safe, but not necessarily optimal - API for changing timings during DVFS or at boot-up This means that you alreeady have callbacks to create a devfreq device driver that supports DVFS on the device. This doesn't need to be a misc device driver then. Nope. The callbacks mentioned above are mainly coming from the clock framework. Ofcourse the clock node trigger with voltage ramps would be triggered by some upper laver governor/framework like CPUFreq/DEVFREQ but as such this is not necessary. This is an indepdent driver and just like CPUFREQ notifies it's users for the frequency change, this driver will be notified to take any action on pre and post notification. Note that, the driver will be notified by regulator framework for the voltage ramp up/down cases too with notifiers. - Temperature alert configuration and handling of temperature alerts, if any for LPDDR2 devices * temperature alert is based on periodic polling of MR4 mode register in DDR devices automatically performed by hardware * timings are de-rated and brought back to nominal when temperature raises and falls respectively This can be a feature overriding max_freq inside the Omap EMIF devfreq device driver though it maybe (or not.. I just don't sure) be better to use thermal framework as well. That's absolute abuse and there is no need to link the temperature handling with DVFS. Reducing frequency can be one of the cooling techniques but that's not related to the temperature alert handling. Temperature handling in the EMIF driver is strictly as per the JDEC specs and that is to de-rate the timings when temperature threshold is crossed. The idea is drivers should be independent of all the global policy governors. Hope this is clear to you. Regards Santosh -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: Re: [PATCH v4 0/7] Add TI EMIF SDRAM controller driver
Kyungmin Parkkmp...@infradead.org 2012-03-17 15:10 (GMT+09:00) Hi, On 3/17/12, Aneesh V wrote: Add a driver for the EMIF SDRAM controller used in TI SoCs EMIF is an SDRAM controller that supports, based on its revision, one or more of LPDDR2/DDR2/DDR3 protocols.This driver adds support for LPDDR2. The driver supports the following features: - Calculates the DDR AC timing parameters to be set in EMIF registers using data from the device data-sheets and based on the DDR frequency. If data from data-sheets is not available default timing values from the JEDEC spec are used. These will be safe, but not necessarily optimal - API for changing timings during DVFS or at boot-up This means that you alreeady have callbacks to create a devfreq device driver that supports DVFS on the device. This doesn't need to be a misc device driver then. - Temperature alert configuration and handling of temperature alerts, if any for LPDDR2 devices * temperature alert is based on periodic polling of MR4 mode register in DDR devices automatically performed by hardware * timings are de-rated and brought back to nominal when temperature raises and falls respectively This can be a feature overriding max_freq inside the Omap EMIF devfreq device driver though it maybe (or not.. I just don't sure) be better to use thermal framework as well. Cheers! MyungJoo - Cache of calculated register values to avoid re-calculating them The driver will need some minor updates when it is eventually integrated with Dynamic Voltage and Frequency Scaling (DVFS). This can not be done now as DVFS support is not available in the mainline yet. Do you see the devfreq? it's designed for non-cpu device frequency. It's role is similar with cpufreq. Now samsung exynos uses devfreq for DRAM bus frequency. Thank you, Kyungmin Park Discussions with Santosh Shilimkar were immensely helpful in shaping up the interfaces. Vibhore Vardhan did the initial code snippet for thermal handling. Testing: - The driver is tested on OMAP4430 SDP. - The driver in a slightly adapted form is also tested on OMAP5. - Since mainline kernel doesn't have DVFS support yet, testing was done using a test module. - Temperature alert handling was tested with simulated interrupts and faked temperature values as testing all cases in real-life scenarios is difficult. - Tested the driver as a module Cc: Greg KH v4: - Converted instances of EXPORT_SYMBOL to EXPORT_SYMBOL_GPL - Removed un-necessary #ifndef __ASSEMBLY__' - Minor formatting fix v2: - Fixed a bug found in the implementation of errata i728 workaround - Fixed the value of frequency printed in debugfs - Dropped the hwmod patch as Paul has already posted a a hwmod series [1] that adds hwmod for EMIF - Converted instances of __init to __init_or_module [1] http://thread.gmane.org/gmane.linux.ports.arm.omap/72855 Aneesh V (7): misc: ddr: add LPDDR2 data from JESD209-2 misc: emif: add register definitions for EMIF misc: emif: add basic infrastructure for EMIF driver misc: emif: handle frequency and voltage change events misc: emif: add interrupt and temperature handling misc: emif: add one-time settings misc: emif: add debugfs entries for emif Documentation/misc-devices/ti-emif.txt | 58 ++ drivers/misc/Kconfig| 12 + drivers/misc/Makefile |1 + drivers/misc/emif.c | 1670 +++ drivers/misc/emif.h | 589 +++ include/linux/platform_data/emif_plat.h | 128 +++ include/misc/jedec_ddr.h| 175 lib/Kconfig |8 + lib/Makefile|2 + lib/jedec_ddr_data.c| 135 +++ 10 files changed, 2778 insertions(+), 0 deletions(-) create mode 100644 Documentation/misc-devices/ti-emif.txt create mode 100644 drivers/misc/emif.c create mode 100644 drivers/misc/emif.h create mode 100644 include/linux/platform_data/emif_plat.h create mode 100644 include/misc/jedec_ddr.h create mode 100644 lib/jedec_ddr_data.c ___ linux-arm-kernel mailing list linux-arm-ker...@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel -- MyungJoo Ham (함명주), PHD System S/W Lab, S/W Platform Team, Software Center Samsung Electronics Cell: +82-10-6714-2858
Re: [PATCH v4 0/7] Add TI EMIF SDRAM controller driver
Hi, On 3/17/12, Aneesh V ane...@ti.com wrote: Add a driver for the EMIF SDRAM controller used in TI SoCs EMIF is an SDRAM controller that supports, based on its revision, one or more of LPDDR2/DDR2/DDR3 protocols.This driver adds support for LPDDR2. The driver supports the following features: - Calculates the DDR AC timing parameters to be set in EMIF registers using data from the device data-sheets and based on the DDR frequency. If data from data-sheets is not available default timing values from the JEDEC spec are used. These will be safe, but not necessarily optimal - API for changing timings during DVFS or at boot-up - Temperature alert configuration and handling of temperature alerts, if any for LPDDR2 devices * temperature alert is based on periodic polling of MR4 mode register in DDR devices automatically performed by hardware * timings are de-rated and brought back to nominal when temperature raises and falls respectively - Cache of calculated register values to avoid re-calculating them The driver will need some minor updates when it is eventually integrated with Dynamic Voltage and Frequency Scaling (DVFS). This can not be done now as DVFS support is not available in the mainline yet. Do you see the devfreq? it's designed for non-cpu device frequency. It's role is similar with cpufreq. Now samsung exynos uses devfreq for DRAM bus frequency. Thank you, Kyungmin Park Discussions with Santosh Shilimkar santosh.shilim...@ti.com were immensely helpful in shaping up the interfaces. Vibhore Vardhan vvard...@gmail.com did the initial code snippet for thermal handling. Testing: - The driver is tested on OMAP4430 SDP. - The driver in a slightly adapted form is also tested on OMAP5. - Since mainline kernel doesn't have DVFS support yet, testing was done using a test module. - Temperature alert handling was tested with simulated interrupts and faked temperature values as testing all cases in real-life scenarios is difficult. - Tested the driver as a module Cc: Greg KH g...@kroah.com v4: - Converted instances of EXPORT_SYMBOL to EXPORT_SYMBOL_GPL - Removed un-necessary #ifndef __ASSEMBLY__' - Minor formatting fix v2: - Fixed a bug found in the implementation of errata i728 workaround - Fixed the value of frequency printed in debugfs - Dropped the hwmod patch as Paul has already posted a a hwmod series [1] that adds hwmod for EMIF - Converted instances of __init to __init_or_module [1] http://thread.gmane.org/gmane.linux.ports.arm.omap/72855 Aneesh V (7): misc: ddr: add LPDDR2 data from JESD209-2 misc: emif: add register definitions for EMIF misc: emif: add basic infrastructure for EMIF driver misc: emif: handle frequency and voltage change events misc: emif: add interrupt and temperature handling misc: emif: add one-time settings misc: emif: add debugfs entries for emif Documentation/misc-devices/ti-emif.txt | 58 ++ drivers/misc/Kconfig| 12 + drivers/misc/Makefile |1 + drivers/misc/emif.c | 1670 +++ drivers/misc/emif.h | 589 +++ include/linux/platform_data/emif_plat.h | 128 +++ include/misc/jedec_ddr.h| 175 lib/Kconfig |8 + lib/Makefile|2 + lib/jedec_ddr_data.c| 135 +++ 10 files changed, 2778 insertions(+), 0 deletions(-) create mode 100644 Documentation/misc-devices/ti-emif.txt create mode 100644 drivers/misc/emif.c create mode 100644 drivers/misc/emif.h create mode 100644 include/linux/platform_data/emif_plat.h create mode 100644 include/misc/jedec_ddr.h create mode 100644 lib/jedec_ddr_data.c ___ linux-arm-kernel mailing list linux-arm-ker...@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
[PATCH v4 0/7] Add TI EMIF SDRAM controller driver
Add a driver for the EMIF SDRAM controller used in TI SoCs EMIF is an SDRAM controller that supports, based on its revision, one or more of LPDDR2/DDR2/DDR3 protocols.This driver adds support for LPDDR2. The driver supports the following features: - Calculates the DDR AC timing parameters to be set in EMIF registers using data from the device data-sheets and based on the DDR frequency. If data from data-sheets is not available default timing values from the JEDEC spec are used. These will be safe, but not necessarily optimal - API for changing timings during DVFS or at boot-up - Temperature alert configuration and handling of temperature alerts, if any for LPDDR2 devices * temperature alert is based on periodic polling of MR4 mode register in DDR devices automatically performed by hardware * timings are de-rated and brought back to nominal when temperature raises and falls respectively - Cache of calculated register values to avoid re-calculating them The driver will need some minor updates when it is eventually integrated with Dynamic Voltage and Frequency Scaling (DVFS). This can not be done now as DVFS support is not available in the mainline yet. Discussions with Santosh Shilimkar santosh.shilim...@ti.com were immensely helpful in shaping up the interfaces. Vibhore Vardhan vvard...@gmail.com did the initial code snippet for thermal handling. Testing: - The driver is tested on OMAP4430 SDP. - The driver in a slightly adapted form is also tested on OMAP5. - Since mainline kernel doesn't have DVFS support yet, testing was done using a test module. - Temperature alert handling was tested with simulated interrupts and faked temperature values as testing all cases in real-life scenarios is difficult. - Tested the driver as a module Cc: Greg KH g...@kroah.com v4: - Converted instances of EXPORT_SYMBOL to EXPORT_SYMBOL_GPL - Removed un-necessary #ifndef __ASSEMBLY__' - Minor formatting fix v2: - Fixed a bug found in the implementation of errata i728 workaround - Fixed the value of frequency printed in debugfs - Dropped the hwmod patch as Paul has already posted a a hwmod series [1] that adds hwmod for EMIF - Converted instances of __init to __init_or_module [1] http://thread.gmane.org/gmane.linux.ports.arm.omap/72855 Aneesh V (7): misc: ddr: add LPDDR2 data from JESD209-2 misc: emif: add register definitions for EMIF misc: emif: add basic infrastructure for EMIF driver misc: emif: handle frequency and voltage change events misc: emif: add interrupt and temperature handling misc: emif: add one-time settings misc: emif: add debugfs entries for emif Documentation/misc-devices/ti-emif.txt | 58 ++ drivers/misc/Kconfig| 12 + drivers/misc/Makefile |1 + drivers/misc/emif.c | 1670 +++ drivers/misc/emif.h | 589 +++ include/linux/platform_data/emif_plat.h | 128 +++ include/misc/jedec_ddr.h| 175 lib/Kconfig |8 + lib/Makefile|2 + lib/jedec_ddr_data.c| 135 +++ 10 files changed, 2778 insertions(+), 0 deletions(-) create mode 100644 Documentation/misc-devices/ti-emif.txt create mode 100644 drivers/misc/emif.c create mode 100644 drivers/misc/emif.h create mode 100644 include/linux/platform_data/emif_plat.h create mode 100644 include/misc/jedec_ddr.h create mode 100644 lib/jedec_ddr_data.c -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
