Re: [PATCH 0/5] Add Maxim 77802 PMIC support
On pon, 2014-06-09 at 09:04 -0700, Doug Anderson wrote: Krzystof, On Mon, Jun 9, 2014 at 3:16 AM, Krzysztof Kozlowski k.kozlow...@samsung.com wrote: On pon, 2014-06-09 at 11:37 +0200, Javier Martinez Canillas wrote: MAX77802 is a PMIC that contains 10 high efficiency Buck regulators, 32 Low-dropout (LDO) regulators, two 32kHz buffered clock outputs, a Real-Time-Clock (RTC) and a I2C interface to program the individual regulators, clocks and the RTC. This series are based on drivers added by Simon Glass to the Chrome OS kernel and adds support for the Maxim 77802 Power Management IC, their regulators, clocks, RTC and I2C interface. It is composed of patches: [PATCH 1/5] mfd: Add driver for Maxim 77802 Power Management IC [PATCH 2/5] regulator: Add driver for Maxim 77802 PMIC regulators [PATCH 3/5] clk: Add driver for Maxim 77802 PMIC clocks [PATCH 4/5] rtc: Add driver for Maxim 77802 PMIC Real-Time-Clock [PATCH 5/5] ARM: dts: Add max77802 device node for exynos5420-peach-pit Patches 1-4 add support for the different devices and Patch 5 enables the MAX77802 PMIC on the Exynos5420 based Peach pit board. Hi, The main mfd, mfd irq, clk and rtc drivers look very similar to max77686 drivers. I haven't checked other Maxim drivers but I think there will be a lot of similarities with them also. It is almost common for Maxim chipsets to share components between each other. I think there is no need in duplicating all that stuff once again in new driver for another Maxim-almost-the-same-as-others-XYZ chipset. Just merge it with max77686 (or other better candidate). The only difference is in regulator driver. I am not sure whether this is a result of differences in chip or differences in driver design. Yes, we thought the same thing when we added support for the max77802 in the ChromeOS tree. Unfortunately it didn't work out half as well as we thought it would. When Javier was asking advice about sending things upstream we suggested that perhaps he should split the two up. You can see the result of the combined driver the ChromeOS tree (the code there is older, probably misnamed as max77xxx, and doesn't have the proper clock pieces, but you can get the gist): https://chromium.googlesource.com/chromiumos/third_party/kernel/+/chromeos-3.8/drivers/regulator/max77xxx-regulator.c https://chromium.googlesource.com/chromiumos/third_party/kernel/+/chromeos-3.8/drivers/rtc/rtc-max77xxx.c Specific problems that made it ugly to have a combined driver: * The RTC has many subtle differences between the 77686 and 77802. They expanded it to handle a 200 year timeframe instead of 100 and that meant that they had to shuffle the bits around everywhere. They also moved it to have the same i2c address as the main PMIC so all addresses are different (see max77686_map in the RTC link above). The difference in RTC registers seems the biggest but it can be solved in readable manner. I see other differences but there aren't many. It just hurts seeing so much code duplication: $ sed -e 's/max77686/max77802/g' -e 's/MAX77686/MAX77802/g' \ -i drivers/rtc/rtc-max77686.c $ diff -ubB drivers/rtc/rtc-max77686.c drivers/rtc/rtc-max77802.c The combined RTC driver from ChromeOS seems fine to me... but I do not insist. * The regulator itself has similar concepts between the two, but the list of bucks / ldos and how they behave is quite different. Trying to understand the complex tables in https://chromium.googlesource.com/chromiumos/third_party/kernel/+/chromeos-3.8/drivers/regulator/max77xxx-regulator.c was not easy. If we really need to write a single driver it certainly can be done, but please look at the above to be sure this is what you want. Sure, I don't stick to the idea of one merged driver where this increases code size and complexity. I see your point that merging regulator drivers won't bring benefits but please: $ sed -e 's/max77686/max77802/g' -e 's/MAX77686/MAX77802/g' \ -i drivers/clk/clk-max77686.c $ diff -ubB drivers/clk/clk-max77686.c drivers/clk/clk-max77802.c The difference in number of clocks (2 vs 3) is not an obstacle here. The same applies to main MFD driver and IRQ code. However MAX77686 doesn't use regmap_irq_chip so it needs changes before merging the IRQ code into one piece. Best regards, Krzysztof NOTE: it's possible that things could be more sane with more driver redesign, possibly making things more data driven. The thing that would be really nice to do would be to avoid all of the crazy regulator_zzz_desc_zzz macros, maybe? I'd have to actually try doing it to be sure it's cleaner, though... -Doug -- To unsubscribe from this list: send the line unsubscribe linux-samsung-soc in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 0/5] Add Maxim 77802 PMIC support
On wto, 2014-06-10 at 00:55 +0200, Javier Martinez Canillas wrote: Hello Krzystof, Thanks a lot for your feedback. On 06/09/2014 06:04 PM, Doug Anderson wrote: Krzystof, On Mon, Jun 9, 2014 at 3:16 AM, Krzysztof Kozlowski k.kozlow...@samsung.com wrote: On pon, 2014-06-09 at 11:37 +0200, Javier Martinez Canillas wrote: MAX77802 is a PMIC that contains 10 high efficiency Buck regulators, 32 Low-dropout (LDO) regulators, two 32kHz buffered clock outputs, a Real-Time-Clock (RTC) and a I2C interface to program the individual regulators, clocks and the RTC. This series are based on drivers added by Simon Glass to the Chrome OS kernel and adds support for the Maxim 77802 Power Management IC, their regulators, clocks, RTC and I2C interface. It is composed of patches: [PATCH 1/5] mfd: Add driver for Maxim 77802 Power Management IC [PATCH 2/5] regulator: Add driver for Maxim 77802 PMIC regulators [PATCH 3/5] clk: Add driver for Maxim 77802 PMIC clocks [PATCH 4/5] rtc: Add driver for Maxim 77802 PMIC Real-Time-Clock [PATCH 5/5] ARM: dts: Add max77802 device node for exynos5420-peach-pit Patches 1-4 add support for the different devices and Patch 5 enables the MAX77802 PMIC on the Exynos5420 based Peach pit board. Hi, The main mfd, mfd irq, clk and rtc drivers look very similar to max77686 drivers. I haven't checked other Maxim drivers but I think there will be a lot of similarities with them also. It is almost common for Maxim chipsets to share components between each other. I think there is no need in duplicating all that stuff once again in new driver for another Maxim-almost-the-same-as-others-XYZ chipset. Just merge it with max77686 (or other better candidate). The only difference is in regulator driver. I am not sure whether this is a result of differences in chip or differences in driver design. Yes, we thought the same thing when we added support for the max77802 in the ChromeOS tree. Unfortunately it didn't work out half as well as we thought it would. When Javier was asking advice about sending things upstream we suggested that perhaps he should split the two up. You can see the result of the combined driver the ChromeOS tree (the code there is older, probably misnamed as max77xxx, and doesn't have the proper clock pieces, but you can get the gist): https://chromium.googlesource.com/chromiumos/third_party/kernel/+/chromeos-3.8/drivers/regulator/max77xxx-regulator.c https://chromium.googlesource.com/chromiumos/third_party/kernel/+/chromeos-3.8/drivers/rtc/rtc-max77xxx.c Specific problems that made it ugly to have a combined driver: * The RTC has many subtle differences between the 77686 and 77802. They expanded it to handle a 200 year timeframe instead of 100 and that meant that they had to shuffle the bits around everywhere. They also moved it to have the same i2c address as the main PMIC so all addresses are different (see max77686_map in the RTC link above). * The regulator itself has similar concepts between the two, but the list of bucks / ldos and how they behave is quite different. Trying to understand the complex tables in https://chromium.googlesource.com/chromiumos/third_party/kernel/+/chromeos-3.8/drivers/regulator/max77xxx-regulator.c was not easy. There are other differences that were not mentioned: - The max77802 uses a single register to enable RTC alarm while max77686 uses 1 bit from a set of registers. But still this will be one additional 'if' statement in one common code... - Each chip has some regulators that are not available and you have to take care of those exceptions (e.g: LDO16, LDO22 and LD31 on max77802). Missing/new regulator does not look like a problem to me in combined driver from ChromeOS. The main problem with combined driver for regulators is that you still need to provide all the regulator_ops/regulator_desc for each of the chipsets. Thus the combined driver is almost as big as two drivers. - The max77802 has 2 clocks outputs while the max77686 has three. This leads to one exception in combined clock driver. This will still reduce LOC. So, as Doug said there are many differences on these two chips besides the regulators. It's true that these two drivers share a lot of the structure and there is code duplication (this applies to most maxim drivers btw) but I have my doubts that the combined approach will make the code more easy to maintain. The biggest problem is the i2c addresses space being different so you need an indirection level to access registers and have duplicated registers definition for each chip. Yep, I agree. I had the same problem with S5M/S2M RTC driver and I am not quite sure that I've chosen the right solution :). If we really need to write a single driver it certainly can be done, but please look at the above to be sure this is what you want. Yes, if the
Re: [PATCH 0/5] Add Maxim 77802 PMIC support
Hello Krzysztof, On 10/06/2014, at 09:32, Krzysztof Kozlowski k.kozlow...@samsung.com wrote: On pon, 2014-06-09 at 09:04 -0700, Doug Anderson wrote: Krzystof, On Mon, Jun 9, 2014 at 3:16 AM, Krzysztof Kozlowski k.kozlow...@samsung.com wrote: On pon, 2014-06-09 at 11:37 +0200, Javier Martinez Canillas wrote: MAX77802 is a PMIC that contains 10 high efficiency Buck regulators, 32 Low-dropout (LDO) regulators, two 32kHz buffered clock outputs, a Real-Time-Clock (RTC) and a I2C interface to program the individual regulators, clocks and the RTC. This series are based on drivers added by Simon Glass to the Chrome OS kernel and adds support for the Maxim 77802 Power Management IC, their regulators, clocks, RTC and I2C interface. It is composed of patches: [PATCH 1/5] mfd: Add driver for Maxim 77802 Power Management IC [PATCH 2/5] regulator: Add driver for Maxim 77802 PMIC regulators [PATCH 3/5] clk: Add driver for Maxim 77802 PMIC clocks [PATCH 4/5] rtc: Add driver for Maxim 77802 PMIC Real-Time-Clock [PATCH 5/5] ARM: dts: Add max77802 device node for exynos5420-peach-pit Patches 1-4 add support for the different devices and Patch 5 enables the MAX77802 PMIC on the Exynos5420 based Peach pit board. Hi, The main mfd, mfd irq, clk and rtc drivers look very similar to max77686 drivers. I haven't checked other Maxim drivers but I think there will be a lot of similarities with them also. It is almost common for Maxim chipsets to share components between each other. I think there is no need in duplicating all that stuff once again in new driver for another Maxim-almost-the-same-as-others-XYZ chipset. Just merge it with max77686 (or other better candidate). The only difference is in regulator driver. I am not sure whether this is a result of differences in chip or differences in driver design. Yes, we thought the same thing when we added support for the max77802 in the ChromeOS tree. Unfortunately it didn't work out half as well as we thought it would. When Javier was asking advice about sending things upstream we suggested that perhaps he should split the two up. You can see the result of the combined driver the ChromeOS tree (the code there is older, probably misnamed as max77xxx, and doesn't have the proper clock pieces, but you can get the gist): https://chromium.googlesource.com/chromiumos/third_party/kernel/+/chromeos-3.8/drivers/regulator/max77xxx-regulator.c https://chromium.googlesource.com/chromiumos/third_party/kernel/+/chromeos-3.8/drivers/rtc/rtc-max77xxx.c Specific problems that made it ugly to have a combined driver: * The RTC has many subtle differences between the 77686 and 77802. They expanded it to handle a 200 year timeframe instead of 100 and that meant that they had to shuffle the bits around everywhere. They also moved it to have the same i2c address as the main PMIC so all addresses are different (see max77686_map in the RTC link above). The difference in RTC registers seems the biggest but it can be solved in readable manner. I see other differences but there aren't many. It just hurts seeing so much code duplication: $ sed -e 's/max77686/max77802/g' -e 's/MAX77686/MAX77802/g' \ -i drivers/rtc/rtc-max77686.c $ diff -ubB drivers/rtc/rtc-max77686.c drivers/rtc/rtc-max77802.c The combined RTC driver from ChromeOS seems fine to me... but I do not insist. * The regulator itself has similar concepts between the two, but the list of bucks / ldos and how they behave is quite different. Trying to understand the complex tables in https://chromium.googlesource.com/chromiumos/third_party/kernel/+/chromeos-3.8/drivers/regulator/max77xxx-regulator.c was not easy. If we really need to write a single driver it certainly can be done, but please look at the above to be sure this is what you want. Sure, I don't stick to the idea of one merged driver where this increases code size and complexity. I see your point that merging regulator drivers won't bring benefits but please: $ sed -e 's/max77686/max77802/g' -e 's/MAX77686/MAX77802/g' \ -i drivers/clk/clk-max77686.c $ diff -ubB drivers/clk/clk-max77686.c drivers/clk/clk-max77802.c I agree that there is too much duplicated code between those two and others Maxim PMIC drivers. I also agree that at some point we have to stop duplicating code and clean up all this. So, I think that instead of trying to make a single driver support two similar but different PMIC I can factor out the generic code in a max-core driver so the PMIC specific code is small and well contained. I'll work on that and post a v2. Thanks a lot for your feedback and best regards, Javier The difference in number of clocks (2 vs 3) is not an obstacle here. The same applies to main MFD driver and IRQ code. However MAX77686 doesn't use regmap_irq_chip so it needs changes before merging the IRQ code into one piece. Best regards, Krzysztof NOTE: it's possible
[PATCH 0/5] Add Maxim 77802 PMIC support
MAX77802 is a PMIC that contains 10 high efficiency Buck regulators, 32 Low-dropout (LDO) regulators, two 32kHz buffered clock outputs, a Real-Time-Clock (RTC) and a I2C interface to program the individual regulators, clocks and the RTC. This series are based on drivers added by Simon Glass to the Chrome OS kernel and adds support for the Maxim 77802 Power Management IC, their regulators, clocks, RTC and I2C interface. It is composed of patches: [PATCH 1/5] mfd: Add driver for Maxim 77802 Power Management IC [PATCH 2/5] regulator: Add driver for Maxim 77802 PMIC regulators [PATCH 3/5] clk: Add driver for Maxim 77802 PMIC clocks [PATCH 4/5] rtc: Add driver for Maxim 77802 PMIC Real-Time-Clock [PATCH 5/5] ARM: dts: Add max77802 device node for exynos5420-peach-pit Patches 1-4 add support for the different devices and Patch 5 enables the MAX77802 PMIC on the Exynos5420 based Peach pit board. Lee, Patches 2-4 depend on Patch 1 so I think that it makes sense if you take 1-4 through your mfd tree once the relevant maintainers ack the drivers added to the other subsystems (regulator, clk and rtc). Patch 5 can go through Kukjin tree since is just DTS changes. Thanks a lot and best regards, Javier -- 2.0.0.rc2 -- To unsubscribe from this list: send the line unsubscribe linux-samsung-soc in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 0/5] Add Maxim 77802 PMIC support
On pon, 2014-06-09 at 11:37 +0200, Javier Martinez Canillas wrote: MAX77802 is a PMIC that contains 10 high efficiency Buck regulators, 32 Low-dropout (LDO) regulators, two 32kHz buffered clock outputs, a Real-Time-Clock (RTC) and a I2C interface to program the individual regulators, clocks and the RTC. This series are based on drivers added by Simon Glass to the Chrome OS kernel and adds support for the Maxim 77802 Power Management IC, their regulators, clocks, RTC and I2C interface. It is composed of patches: [PATCH 1/5] mfd: Add driver for Maxim 77802 Power Management IC [PATCH 2/5] regulator: Add driver for Maxim 77802 PMIC regulators [PATCH 3/5] clk: Add driver for Maxim 77802 PMIC clocks [PATCH 4/5] rtc: Add driver for Maxim 77802 PMIC Real-Time-Clock [PATCH 5/5] ARM: dts: Add max77802 device node for exynos5420-peach-pit Patches 1-4 add support for the different devices and Patch 5 enables the MAX77802 PMIC on the Exynos5420 based Peach pit board. Hi, The main mfd, mfd irq, clk and rtc drivers look very similar to max77686 drivers. I haven't checked other Maxim drivers but I think there will be a lot of similarities with them also. It is almost common for Maxim chipsets to share components between each other. I think there is no need in duplicating all that stuff once again in new driver for another Maxim-almost-the-same-as-others-XYZ chipset. Just merge it with max77686 (or other better candidate). The only difference is in regulator driver. I am not sure whether this is a result of differences in chip or differences in driver design. Best regards, Krzysztof Lee, Patches 2-4 depend on Patch 1 so I think that it makes sense if you take 1-4 through your mfd tree once the relevant maintainers ack the drivers added to the other subsystems (regulator, clk and rtc). Patch 5 can go through Kukjin tree since is just DTS changes. Thanks a lot and best regards, Javier -- To unsubscribe from this list: send the line unsubscribe linux-samsung-soc in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 0/5] Add Maxim 77802 PMIC support
Krzystof, On Mon, Jun 9, 2014 at 3:16 AM, Krzysztof Kozlowski k.kozlow...@samsung.com wrote: On pon, 2014-06-09 at 11:37 +0200, Javier Martinez Canillas wrote: MAX77802 is a PMIC that contains 10 high efficiency Buck regulators, 32 Low-dropout (LDO) regulators, two 32kHz buffered clock outputs, a Real-Time-Clock (RTC) and a I2C interface to program the individual regulators, clocks and the RTC. This series are based on drivers added by Simon Glass to the Chrome OS kernel and adds support for the Maxim 77802 Power Management IC, their regulators, clocks, RTC and I2C interface. It is composed of patches: [PATCH 1/5] mfd: Add driver for Maxim 77802 Power Management IC [PATCH 2/5] regulator: Add driver for Maxim 77802 PMIC regulators [PATCH 3/5] clk: Add driver for Maxim 77802 PMIC clocks [PATCH 4/5] rtc: Add driver for Maxim 77802 PMIC Real-Time-Clock [PATCH 5/5] ARM: dts: Add max77802 device node for exynos5420-peach-pit Patches 1-4 add support for the different devices and Patch 5 enables the MAX77802 PMIC on the Exynos5420 based Peach pit board. Hi, The main mfd, mfd irq, clk and rtc drivers look very similar to max77686 drivers. I haven't checked other Maxim drivers but I think there will be a lot of similarities with them also. It is almost common for Maxim chipsets to share components between each other. I think there is no need in duplicating all that stuff once again in new driver for another Maxim-almost-the-same-as-others-XYZ chipset. Just merge it with max77686 (or other better candidate). The only difference is in regulator driver. I am not sure whether this is a result of differences in chip or differences in driver design. Yes, we thought the same thing when we added support for the max77802 in the ChromeOS tree. Unfortunately it didn't work out half as well as we thought it would. When Javier was asking advice about sending things upstream we suggested that perhaps he should split the two up. You can see the result of the combined driver the ChromeOS tree (the code there is older, probably misnamed as max77xxx, and doesn't have the proper clock pieces, but you can get the gist): https://chromium.googlesource.com/chromiumos/third_party/kernel/+/chromeos-3.8/drivers/regulator/max77xxx-regulator.c https://chromium.googlesource.com/chromiumos/third_party/kernel/+/chromeos-3.8/drivers/rtc/rtc-max77xxx.c Specific problems that made it ugly to have a combined driver: * The RTC has many subtle differences between the 77686 and 77802. They expanded it to handle a 200 year timeframe instead of 100 and that meant that they had to shuffle the bits around everywhere. They also moved it to have the same i2c address as the main PMIC so all addresses are different (see max77686_map in the RTC link above). * The regulator itself has similar concepts between the two, but the list of bucks / ldos and how they behave is quite different. Trying to understand the complex tables in https://chromium.googlesource.com/chromiumos/third_party/kernel/+/chromeos-3.8/drivers/regulator/max77xxx-regulator.c was not easy. If we really need to write a single driver it certainly can be done, but please look at the above to be sure this is what you want. NOTE: it's possible that things could be more sane with more driver redesign, possibly making things more data driven. The thing that would be really nice to do would be to avoid all of the crazy regulator_zzz_desc_zzz macros, maybe? I'd have to actually try doing it to be sure it's cleaner, though... -Doug -- To unsubscribe from this list: send the line unsubscribe linux-samsung-soc in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 0/5] Add Maxim 77802 PMIC support
Hello Krzystof, Thanks a lot for your feedback. On 06/09/2014 06:04 PM, Doug Anderson wrote: Krzystof, On Mon, Jun 9, 2014 at 3:16 AM, Krzysztof Kozlowski k.kozlow...@samsung.com wrote: On pon, 2014-06-09 at 11:37 +0200, Javier Martinez Canillas wrote: MAX77802 is a PMIC that contains 10 high efficiency Buck regulators, 32 Low-dropout (LDO) regulators, two 32kHz buffered clock outputs, a Real-Time-Clock (RTC) and a I2C interface to program the individual regulators, clocks and the RTC. This series are based on drivers added by Simon Glass to the Chrome OS kernel and adds support for the Maxim 77802 Power Management IC, their regulators, clocks, RTC and I2C interface. It is composed of patches: [PATCH 1/5] mfd: Add driver for Maxim 77802 Power Management IC [PATCH 2/5] regulator: Add driver for Maxim 77802 PMIC regulators [PATCH 3/5] clk: Add driver for Maxim 77802 PMIC clocks [PATCH 4/5] rtc: Add driver for Maxim 77802 PMIC Real-Time-Clock [PATCH 5/5] ARM: dts: Add max77802 device node for exynos5420-peach-pit Patches 1-4 add support for the different devices and Patch 5 enables the MAX77802 PMIC on the Exynos5420 based Peach pit board. Hi, The main mfd, mfd irq, clk and rtc drivers look very similar to max77686 drivers. I haven't checked other Maxim drivers but I think there will be a lot of similarities with them also. It is almost common for Maxim chipsets to share components between each other. I think there is no need in duplicating all that stuff once again in new driver for another Maxim-almost-the-same-as-others-XYZ chipset. Just merge it with max77686 (or other better candidate). The only difference is in regulator driver. I am not sure whether this is a result of differences in chip or differences in driver design. Yes, we thought the same thing when we added support for the max77802 in the ChromeOS tree. Unfortunately it didn't work out half as well as we thought it would. When Javier was asking advice about sending things upstream we suggested that perhaps he should split the two up. You can see the result of the combined driver the ChromeOS tree (the code there is older, probably misnamed as max77xxx, and doesn't have the proper clock pieces, but you can get the gist): https://chromium.googlesource.com/chromiumos/third_party/kernel/+/chromeos-3.8/drivers/regulator/max77xxx-regulator.c https://chromium.googlesource.com/chromiumos/third_party/kernel/+/chromeos-3.8/drivers/rtc/rtc-max77xxx.c Specific problems that made it ugly to have a combined driver: * The RTC has many subtle differences between the 77686 and 77802. They expanded it to handle a 200 year timeframe instead of 100 and that meant that they had to shuffle the bits around everywhere. They also moved it to have the same i2c address as the main PMIC so all addresses are different (see max77686_map in the RTC link above). * The regulator itself has similar concepts between the two, but the list of bucks / ldos and how they behave is quite different. Trying to understand the complex tables in https://chromium.googlesource.com/chromiumos/third_party/kernel/+/chromeos-3.8/drivers/regulator/max77xxx-regulator.c was not easy. There are other differences that were not mentioned: - The max77802 uses a single register to enable RTC alarm while max77686 uses 1 bit from a set of registers. - Each chip has some regulators that are not available and you have to take care of those exceptions (e.g: LDO16, LDO22 and LD31 on max77802). - The max77802 has 2 clocks outputs while the max77686 has three. So, as Doug said there are many differences on these two chips besides the regulators. It's true that these two drivers share a lot of the structure and there is code duplication (this applies to most maxim drivers btw) but I have my doubts that the combined approach will make the code more easy to maintain. The biggest problem is the i2c addresses space being different so you need an indirection level to access registers and have duplicated registers definition for each chip. If we really need to write a single driver it certainly can be done, but please look at the above to be sure this is what you want. Yes, if the combined driver is preferred over having a separate driver for max77802 then I will try to find the more elegant way to merge both drivers. But I tried to do it already and I can't say I liked the end result more than having two separate drivers. NOTE: it's possible that things could be more sane with more driver redesign, possibly making things more data driven. The thing that would be really nice to do would be to avoid all of the crazy regulator_zzz_desc_zzz macros, maybe? I'd have to actually try doing it to be sure it's cleaner, though... Another option is to use an hybrid approach. Merge the mfd core, irq and clk drivers but have different platform drivers for rtc and regulators. Still the end result is not great imho but better
Re: [PATCH 0/5] Add Maxim 77802 PMIC support
Javier, On Mon, Jun 9, 2014 at 3:55 PM, Javier Martinez Canillas javier.marti...@collabora.co.uk wrote: * The RTC has many subtle differences between the 77686 and 77802. They expanded it to handle a 200 year timeframe instead of 100 and that meant that they had to shuffle the bits around everywhere. They also moved it to have the same i2c address as the main PMIC so all addresses are different (see max77686_map in the RTC link above). There are other differences that were not mentioned: - The max77802 uses a single register to enable RTC alarm while max77686 uses 1 bit from a set of registers. Ironically this is one and the same issue, but you're right that it's more major than I made it out to be. See RTCYEARA2. My theory is that to account for more possible year values they needed all 8 bits. That meant that the enable bit needed to move to a different register. ...and once you moved one enable you might as well move them all, I guess. -- To unsubscribe from this list: send the line unsubscribe linux-samsung-soc in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
