| Message ID | 1400238230-26357-3-git-send-email-pekon@ti.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Pekon, On 05/16/2014 02:03 PM, Pekon Gupta wrote: > Adds pinmux and DT node for Micron (MT29F4G08AB) x8 NAND device present on > am437x-gp-evm board. > (1) As NAND Flash data lines are muxed with eMMC, Thus at a given time either > eMMC or NAND can be enabled. Selection between eMMC and NAND is controlled: > (a) By dynamically driving following GPIO pin from software > SPI2_CS0(GPIO) == 0 NAND is selected (default) > SPI2_CS0(GPIO) == 1 eMMC is selected > (b) By statically using Jumper (J89) on the board > > (2) As NAND device connnected to this board has page-size=4K and oob-size=224, > So ROM code expects boot-loaders to be flashed in BCH16 ECC scheme for > NAND boot. > > Signed-off-by: Pekon Gupta <pekon@ti.com> > Reviewed-by: Javier Martinez Canillas <javier@dowhile0.org> > --- > arch/arm/boot/dts/am437x-gp-evm.dts | 108 ++++++++++++++++++++++++++++++++++++ > 1 file changed, 108 insertions(+) > > diff --git a/arch/arm/boot/dts/am437x-gp-evm.dts b/arch/arm/boot/dts/am437x-gp-evm.dts > index 30ace1b..97b71e6 100644 > --- a/arch/arm/boot/dts/am437x-gp-evm.dts > +++ b/arch/arm/boot/dts/am437x-gp-evm.dts > @@ -150,6 +150,27 @@ > 0x14c (PIN_INPUT_PULLDOWN | MUX_MODE7) > >; > }; > + > + nand_flash_x8: nand_flash_x8 { > + pinctrl-single,pins = < > + 0x26c(PIN_OUTPUT_PULLDOWN | MUX_MODE7) /* spi2_cs0.gpio/eMMCorNANDsel */ > + 0x0 (PIN_INPUT | MUX_MODE0) /* gpmc_ad0.gpmc_ad0 */ > + 0x4 (PIN_INPUT | MUX_MODE0) /* gpmc_ad1.gpmc_ad1 */ > + 0x8 (PIN_INPUT | MUX_MODE0) /* gpmc_ad2.gpmc_ad2 */ > + 0xc (PIN_INPUT | MUX_MODE0) /* gpmc_ad3.gpmc_ad3 */ > + 0x10 (PIN_INPUT | MUX_MODE0) /* gpmc_ad4.gpmc_ad4 */ > + 0x14 (PIN_INPUT | MUX_MODE0) /* gpmc_ad5.gpmc_ad5 */ > + 0x18 (PIN_INPUT | MUX_MODE0) /* gpmc_ad6.gpmc_ad6 */ > + 0x1c (PIN_INPUT | MUX_MODE0) /* gpmc_ad7.gpmc_ad7 */ > + 0x70 (PIN_INPUT_PULLUP | MUX_MODE0) /* gpmc_wait0.gpmc_wait0 */ > + 0x74 (PIN_OUTPUT_PULLUP | MUX_MODE7) /* gpmc_wpn.gpmc_wpn */ > + 0x7c (PIN_OUTPUT | MUX_MODE0) /* gpmc_csn0.gpmc_csn0 */ > + 0x90 (PIN_OUTPUT | MUX_MODE0) /* gpmc_advn_ale.gpmc_advn_ale */ > + 0x94 (PIN_OUTPUT | MUX_MODE0) /* gpmc_oen_ren.gpmc_oen_ren */ > + 0x98 (PIN_OUTPUT | MUX_MODE0) /* gpmc_wen.gpmc_wen */ > + 0x9c (PIN_OUTPUT | MUX_MODE0) /* gpmc_be0n_cle.gpmc_be0n_cle */ > + >; > + }; > }; > > &i2c0 { > @@ -246,3 +267,90 @@ > phy_id = <&davinci_mdio>, <0>; > phy-mode = "rgmii"; > }; > + > +&elm { > + status = "okay"; > +}; > + > +&gpmc { > + status = "okay"; > + pinctrl-names = "default"; > + pinctrl-0 = <&nand_flash_x8>; > + ranges = <0 0 0 0x01000000>; /* minimum GPMC partition = 16MB */ > + nand@0,0 { > + reg = <0 0 0x37c>; /* device IO registers */ This register space is used by the parent GPMC node as well as the NAND controller. So doing a request_and_ioremap() on this space will fail as it is already taken by the GPMC driver. Further, the GPMC register space doesn't map to the GPMC memory map created by this Chip select but it is mapped to L3_IO space. i.e. (physical address 0x6e00 0000) We could have split the GPMC register space into GPMC part and NAND part but to add to the complexity, the register spaces for GPMC vs NAND are interleaved so it can't be easily split up. The way the NAND driver is currently written is that it expects the register addresses to come via platform data, primarily to get around this address interleaving issue. Apart from the GPMC register space, the NAND controller uses 4 bytes of GPMC memory map for I/O, and that is something that could be reflected here. e.g. reg = <0 0 4>; /* NAND I/O space */ But still, the start address can't be 0 and has to be assigned when this CS region is mapped. It is still unclear to me how that can be done. cheers, -roger > + ti,nand-ecc-opt = "bch8"; > + ti,elm-id = <&elm>; > + nand-bus-width = <8>; > + gpmc,device-width = <1>; > + gpmc,sync-clk-ps = <0>; > + gpmc,cs-on-ns = <0>; > + gpmc,cs-rd-off-ns = <40>; > + gpmc,cs-wr-off-ns = <40>; > + gpmc,adv-on-ns = <0>; > + gpmc,adv-rd-off-ns = <25>; > + gpmc,adv-wr-off-ns = <25>; > + gpmc,we-on-ns = <0>; > + gpmc,we-off-ns = <20>; > + gpmc,oe-on-ns = <3>; > + gpmc,oe-off-ns = <30>; > + gpmc,access-ns = <30>; > + gpmc,rd-cycle-ns = <40>; > + gpmc,wr-cycle-ns = <40>; > + gpmc,wait-pin = <0>; > + gpmc,wait-on-read; > + gpmc,wait-on-write; > + gpmc,bus-turnaround-ns = <0>; > + gpmc,cycle2cycle-delay-ns = <0>; > + gpmc,clk-activation-ns = <0>; > + gpmc,wait-monitoring-ns = <0>; > + gpmc,wr-access-ns = <40>; > + gpmc,wr-data-mux-bus-ns = <0>; > + /* MTD partition table */ > + /* All SPL-* partitions are sized to minimal length > + * which can be independently programmable. For > + * NAND flash this is equal to size of erase-block */ > + #address-cells = <1>; > + #size-cells = <1>; > + partition@0 { > + label = "NAND.SPL"; > + reg = <0x00000000 0x00040000>; > + }; > + partition@1 { > + label = "NAND.SPL.backup1"; > + reg = <0x00040000 0x00040000>; > + }; > + partition@2 { > + label = "NAND.SPL.backup2"; > + reg = <0x00080000 0x00040000>; > + }; > + partition@3 { > + label = "NAND.SPL.backup3"; > + reg = <0x000c0000 0x00040000>; > + }; > + partition@4 { > + label = "NAND.u-boot-spl-os"; > + reg = <0x00100000 0x00080000>; > + }; > + partition@5 { > + label = "NAND.u-boot"; > + reg = <0x00180000 0x00100000>; > + }; > + partition@6 { > + label = "NAND.u-boot-env"; > + reg = <0x00280000 0x00040000>; > + }; > + partition@7 { > + label = "NAND.u-boot-env.backup1"; > + reg = <0x002c0000 0x00040000>; > + }; > + partition@8 { > + label = "NAND.kernel"; > + reg = <0x00300000 0x00700000>; > + }; > + partition@9 { > + label = "NAND.file-system"; > + reg = <0x00a00000 0x1f600000>; > + }; > + }; > +}; > -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Roger, >From: Quadros, Roger > [...] >> +&gpmc { >> + status = "okay"; >> + pinctrl-names = "default"; >> + pinctrl-0 = <&nand_flash_x8>; >> + ranges = <0 0 0 0x01000000>; /* minimum GPMC partition = 16MB */ >> + nand@0,0 { >> + reg = <0 0 0x37c>; /* device IO registers */ > >This register space is used by the parent GPMC node as well as the NAND controller. So doing a >request_and_ioremap() on this space will fail as it is already taken by the GPMC driver. > >Further, the GPMC register space doesn't map to the GPMC memory map created by this Chip select >but it is mapped to L3_IO space. i.e. (physical address 0x6e00 0000) > >We could have split the GPMC register space into GPMC part and NAND part but to add to the >complexity, the register spaces for GPMC vs NAND are interleaved so it can't be easily split up. Sorry I din't get this part. NAND is one of the devices supported by GPMC controller. Hardware wise the it's the same engine is used for NAND, NOR and OneNAND and even other parallel interfaces like Camera, Ethernet, etc.. So how can be NAND and GPMC registers space be splitted ? I see gpmc.c as generic controller driver, which just does initializations and registering the device. Then it's upto the individual protocol drivers to probe the device and attach it to respective sub-system; like; (a) drivers/mtd/nand/omap2.c for NAND (b) drivers/mtd/chips/cfi_probe.c for NOR ... > The way >the NAND driver is currently written is that it expects the register addresses to come via platform data, >primarily to get around this address interleaving issue. > Yes, that is right. I don't know the historical reasons but that is correct also because, (1) large set of GPMC register configurations are common across all types of devices (like NAND, NOR, OneNAND, Ethernet). These register configurations define the signal timings and physical attributes of device (like device width, etc). (2) Individual protocol drivers (a) and (b) only uses a sub-set of registers for transferring data, much of which is based on type of protocol. So, large part of GPMC configurations remains static and can be Shared across all types of devices, hence those are put in gpmc.c >Apart from the GPMC register space, the NAND controller uses 4 bytes of GPMC memory map for I/O, >and that is something that could be reflected here. > >e.g. > reg = <0 0 4>; /* NAND I/O space */ > >But still, the start address can't be 0 and has to be assigned when this CS region is mapped. It is still >unclear to me how that can be done. > Yes, NAND is not directly mapped. So only 4-bytes of I/O size will do. But where to map these 4 bytes ? and which 4-bytes to map. So I have included complete GPMC register space-size. Also since GPMC has a constrain that every chip-select must have minimum of 16MB memory. So we specify it via <range> property to keep GPMC mapping consistent across all NAND, NOR, OneNAND, etc.. If you have any better approach in mind for keeping consistent memory mapping across different types of devices, then please suggest .. I'll try to get this done in next set of patches, if not these. Or May be you can take over as part of GPMC transition. >cheers, >-roger > with regards, pekon -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 05/16/2014 04:58 PM, Gupta, Pekon wrote: > Hi Roger, > >> From: Quadros, Roger >> > [...] >>> +&gpmc { >>> + status = "okay"; >>> + pinctrl-names = "default"; >>> + pinctrl-0 = <&nand_flash_x8>; >>> + ranges = <0 0 0 0x01000000>; /* minimum GPMC partition = 16MB */ >>> + nand@0,0 { >>> + reg = <0 0 0x37c>; /* device IO registers */ >> >> This register space is used by the parent GPMC node as well as the NAND controller. So doing a >> request_and_ioremap() on this space will fail as it is already taken by the GPMC driver. >> >> Further, the GPMC register space doesn't map to the GPMC memory map created by this Chip select >> but it is mapped to L3_IO space. i.e. (physical address 0x6e00 0000) >> >> We could have split the GPMC register space into GPMC part and NAND part but to add to the >> complexity, the register spaces for GPMC vs NAND are interleaved so it can't be easily split up. > Sorry I din't get this part. > NAND is one of the devices supported by GPMC controller. > Hardware wise the it's the same engine is used for NAND, NOR and OneNAND But GPMC register space is only used for 2 things, Chip Select configuration and NAND driver. GPMC registers are not used for NOR, OneNAND or other memory accessible devices. They don't need GPMC registers because their registers are mapped in the GPMC I/O space. > and even other parallel interfaces like Camera, Ethernet, etc.. > So how can be NAND and GPMC registers space be splitted ? - all Chip select configuration registers i.e. GPMC_CONFIG* should go to GPMC device - all the GPMC_NAND_*, GPMC_ECC_, and GPMC_BCH_* registers go to NAND device The tricky part is that all these registers are interleaved among each other and so the register map is fragmented. > > I see gpmc.c as generic controller driver, which just does initializations > and registering the device. Then it's upto the individual protocol drivers > to probe the device and attach it to respective sub-system; like; > (a) drivers/mtd/nand/omap2.c for NAND > (b) drivers/mtd/chips/cfi_probe.c for NOR > ... omap2.c needs GPMC registers, but cfi_probe.c and others don't need them. > > >> The way >> the NAND driver is currently written is that it expects the register addresses to come via platform data, >> primarily to get around this address interleaving issue. >> > Yes, that is right. > I don't know the historical reasons but that is correct also because, > (1) large set of GPMC register configurations are common across all > types of devices (like NAND, NOR, OneNAND, Ethernet). These > register configurations define the signal timings and physical attributes > of device (like device width, etc). > > (2) Individual protocol drivers (a) and (b) only uses a sub-set of registers > for transferring data, much of which is based on type of protocol. > > So, large part of GPMC configurations remains static and can be > Shared across all types of devices, hence those are put in gpmc.c Right, so just the GPMC configuration part needs to be with GPMC driver. The NAND controller bits don't need to be. > > >> Apart from the GPMC register space, the NAND controller uses 4 bytes of GPMC memory map for I/O, >> and that is something that could be reflected here. >> >> e.g. >> reg = <0 0 4>; /* NAND I/O space */ >> >> But still, the start address can't be 0 and has to be assigned when this CS region is mapped. It is still >> unclear to me how that can be done. >> > Yes, NAND is not directly mapped. So only 4-bytes of I/O size will do. > But where to map these 4 bytes ? and which 4-bytes to map. > So I have included complete GPMC register space-size. That is not the right solution. The mapping is done in the gpmc driver in gpmc_cs_request()/gpmc_cs_remap(). If a random address (meeting GPMC alignment needs) is specified within the GPMC 1GB space, the GPMC driver should configure the CS to map to that address. If 0 is specified then the GPMC must map it automatically to a sane address and then update the reg property before instantiating the child node's platform device. For the NAND controller, we don't even create a child device based on the OF node but instead legacy platform device, so this reg property isn't being even used. > > Also since GPMC has a constrain that every chip-select must have > minimum of 16MB memory. So we specify it via <range> property > to keep GPMC mapping consistent across all NAND, NOR, OneNAND, etc.. > > If you have any better approach in mind for keeping consistent > memory mapping across different types of devices, then please suggest .. > I'll try to get this done in next set of patches, if not these. > Or > May be you can take over as part of GPMC transition. As the driver doesn't rely on the reg address portion (at least for the NAND driver), you can leave this option out for now. cheers, -roger -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
* Roger Quadros <rogerq@ti.com> [140516 05:23]: > On 05/16/2014 02:03 PM, Pekon Gupta wrote: > > +&gpmc { > > + status = "okay"; > > + pinctrl-names = "default"; > > + pinctrl-0 = <&nand_flash_x8>; > > + ranges = <0 0 0 0x01000000>; /* minimum GPMC partition = 16MB */ > > + nand@0,0 { > > + reg = <0 0 0x37c>; /* device IO registers */ > > This register space is used by the parent GPMC node as well as the NAND controller. So doing a request_and_ioremap() on this space will fail as it is already taken by the GPMC driver. > > Further, the GPMC register space doesn't map to the GPMC memory map created by this Chip select but it is mapped to L3_IO space. i.e. (physical address 0x6e00 0000) > > We could have split the GPMC register space into GPMC part and NAND part but to add to the complexity, the register spaces for GPMC vs NAND are interleaved so it can't be easily split up. The way the NAND driver is currently written is that it expects the register addresses to come via platform data, primarily to get around this address interleaving issue. > > Apart from the GPMC register space, the NAND controller uses 4 bytes of GPMC memory map for I/O, and that is something that could be reflected here. > > e.g. > reg = <0 0 4>; /* NAND I/O space */ Guys, the reg size here is size of the IO region for the NAND driver, it should not have anything to do with the GPMC registers for the GPMC functions that the NAND driver may call. So it sounds like 0x37c is wrong, and 4 is the right value if the NAND chip has only one IO register. > But still, the start address can't be 0 and has to be assigned when this CS region is mapped. It is still unclear to me how that can be done. If the offset for the NAND driver needs to be different from 0, it can be in the offset. For example, the smsc,lan91c94 driver wants the IO address space to be at offset 0x300 to avoid some extra warnings during the boot. So for that, the reg entry is: reg = <1 0x300 0xf>; Where we have: 1 = chip select 0x300 = offset of smsc device register IO space from the start of 16MB minimum GPMC partition 0xf = size of smsc device register IO space that the Ethernet driver ioremaps Regards, Tony -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Tony, Roger, >From: Tony Lindgren [mailto:tony@atomide.com] > >* Roger Quadros <rogerq@ti.com> [140516 05:23]: >> On 05/16/2014 02:03 PM, Pekon Gupta wrote: >> > +&gpmc { >> > + status = "okay"; >> > + pinctrl-names = "default"; >> > + pinctrl-0 = <&nand_flash_x8>; >> > + ranges = <0 0 0 0x01000000>; /* minimum GPMC partition = 16MB */ >> > + nand@0,0 { >> > + reg = <0 0 0x37c>; /* device IO registers */ >> >> This register space is used by the parent GPMC node as well as the NAND controller. So doing a >request_and_ioremap() on this space will fail as it is already taken by the GPMC driver. >> >> Further, the GPMC register space doesn't map to the GPMC memory map created by this Chip select >but it is mapped to L3_IO space. i.e. (physical address 0x6e00 0000) >> >> We could have split the GPMC register space into GPMC part and NAND part but to add to the >complexity, the register spaces for GPMC vs NAND are interleaved so it can't be easily split up. The way >the NAND driver is currently written is that it expects the register addresses to come via platform data, >primarily to get around this address interleaving issue. >> >> Apart from the GPMC register space, the NAND controller uses 4 bytes of GPMC memory map for >I/O, and that is something that could be reflected here. >> >> e.g. >> reg = <0 0 4>; /* NAND I/O space */ > >Guys, the reg size here is size of the IO region for the >NAND driver, it should not have anything to do with the GPMC >registers for the GPMC functions that the NAND driver may call. > >So it sounds like 0x37c is wrong, and 4 is the right value if >the NAND chip has only one IO register. > Yes, Roger and myself both agree on the actual size of 4. But what I'm not sure is what should be offset for a io-remapped region. Apologies for my ignorance here, as I'm not good in this memory mapping concept.. - I understand that for 'memory mapped' device <offset> is with respect to base-address of chip-select. - But for indirectly mapped device (like NAND) how is <offset> calculated? Example: For CS0 in GPMC .. GPMC_NAND_COMMAND_0 = 0x007c GPMC_NAND_ADDRESS_0 = 0x0080 GPMC_NAND_DATA_0 = 0x0084 (1) Now, should the 'offset' for <reg> property used for NAND node connected at CS=0. reg = <0 ?? 4> (a) Should it be equal to 'GPMC_NAND_ADDRESS_0'? OR (b) There is no relation between 'GPMC register' and 'NAND partition' offset? (2) If considering (a) then should size consider only GPMC_NAND_ADDRESS_0 or also include GPMC_NAND_COMMAND_0 and GPMC_NAND_DATA_0? This is why I used the size of complete GPMC register space for NAND region also. >> But still, the start address can't be 0 and has to be assigned when this CS region is mapped. It is still >unclear to me how that can be done. > >If the offset for the NAND driver needs to be different from 0, >it can be in the offset. For example, the smsc,lan91c94 driver >wants the IO address space to be at offset 0x300 to avoid some >extra warnings during the boot. So for that, the reg entry is: > >reg = <1 0x300 0xf>; > >Where we have: > >1 = chip select >0x300 = offset of smsc device register IO space from the start of > 16MB minimum GPMC partition This is where my confusion lies, where is the 0x300 coming from? Is this the offset of I/O register in given Ethernet IP register space? >0xf = size of smsc device register IO space that the Ethernet > driver ioremaps > with regards, pekon -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Pekon, On 05/16/2014 09:52 PM, Gupta, Pekon wrote: > Hi Tony, Roger, > >> From: Tony Lindgren [mailto:tony@atomide.com] >> >> * Roger Quadros <rogerq@ti.com> [140516 05:23]: >>> On 05/16/2014 02:03 PM, Pekon Gupta wrote: >>>> +&gpmc { >>>> + status = "okay"; >>>> + pinctrl-names = "default"; >>>> + pinctrl-0 = <&nand_flash_x8>; >>>> + ranges = <0 0 0 0x01000000>; /* minimum GPMC partition = 16MB */ >>>> + nand@0,0 { >>>> + reg = <0 0 0x37c>; /* device IO registers */ >>> >>> This register space is used by the parent GPMC node as well as the NAND controller. So doing a >> request_and_ioremap() on this space will fail as it is already taken by the GPMC driver. >>> >>> Further, the GPMC register space doesn't map to the GPMC memory map created by this Chip select >> but it is mapped to L3_IO space. i.e. (physical address 0x6e00 0000) >>> >>> We could have split the GPMC register space into GPMC part and NAND part but to add to the >> complexity, the register spaces for GPMC vs NAND are interleaved so it can't be easily split up. The way >> the NAND driver is currently written is that it expects the register addresses to come via platform data, >> primarily to get around this address interleaving issue. >>> >>> Apart from the GPMC register space, the NAND controller uses 4 bytes of GPMC memory map for >> I/O, and that is something that could be reflected here. >>> >>> e.g. >>> reg = <0 0 4>; /* NAND I/O space */ >> >> Guys, the reg size here is size of the IO region for the >> NAND driver, it should not have anything to do with the GPMC >> registers for the GPMC functions that the NAND driver may call. >> >> So it sounds like 0x37c is wrong, and 4 is the right value if >> the NAND chip has only one IO register. >> > Yes, Roger and myself both agree on the actual size of 4. > But what I'm not sure is what should be offset for a io-remapped region. > > Apologies for my ignorance here, as I'm not good in this memory mapping concept.. > - I understand that for 'memory mapped' device <offset> is with respect to > base-address of chip-select. > - But for indirectly mapped device (like NAND) how is <offset> calculated? This would depend on what the NAND driver expects. In the current OMAP nand driver it expects only the memory mapped NAND I/O resource. > > Example: For CS0 in GPMC .. > GPMC_NAND_COMMAND_0 = 0x007c > GPMC_NAND_ADDRESS_0 = 0x0080 > GPMC_NAND_DATA_0 = 0x0084 OK, let's say that we want to update that NAND driver to accept a second memory resource which would be the GPMC registers starting from GPMC_NAND_COMMAND_0 (phy.addr 0x6e00 007c), then we need to define a new address in the ranges property of the gpmc node. Something like so ranges = <0 0 0x00000000 0x01000000 /* GPMC external map */ 1 0 0x6e000000 0x0000037c>; /* GPMC register map */ nand@0,0 { reg = <0 0 4 /* NAND I/O space */ 1 0x7c 3> /* NAND controller registers */ Since range 1 started from 0x6e000000 we specify offset as 0x7c. But at the moment the NAND driver doesn't directly access the GPMC register map so it should be sufficient to just specify the I/O space. > > (1) Now, should the 'offset' for <reg> property used for NAND node > connected at CS=0. reg = <0 ?? 4> > (a) Should it be equal to 'GPMC_NAND_ADDRESS_0'? > OR > (b) There is no relation between 'GPMC register' and 'NAND partition' offset? > > (2) If considering (a) then should size consider only GPMC_NAND_ADDRESS_0 > or also include GPMC_NAND_COMMAND_0 and GPMC_NAND_DATA_0? > > This is why I used the size of complete GPMC register space for NAND region also. > > >>> But still, the start address can't be 0 and has to be assigned when this CS region is mapped. It is still >> unclear to me how that can be done. >> >> If the offset for the NAND driver needs to be different from 0, >> it can be in the offset. For example, the smsc,lan91c94 driver >> wants the IO address space to be at offset 0x300 to avoid some >> extra warnings during the boot. So for that, the reg entry is: >> >> reg = <1 0x300 0xf>; >> >> Where we have: >> >> 1 = chip select >> 0x300 = offset of smsc device register IO space from the start of >> 16MB minimum GPMC partition > > This is where my confusion lies, where is the 0x300 coming from? > Is this the offset of I/O register in given Ethernet IP register space? I'm not sure about 0x300 but this is my guess. The smsc register addresses start at 0x300. In theory this could be aligned to the CS start address and we could have worked with 0 offset. But because of the 16MB min. granularity requirement for the GPMC CS start address, A23:A0 have to be 0. As CS start address can never be aligned to 0x300 we can't have 0 offset. cheers, -roger -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
* Roger Quadros <rogerq@ti.com> [140516 13:30]: > Pekon, > > On 05/16/2014 09:52 PM, Gupta, Pekon wrote: > > Hi Tony, Roger, > > > >> From: Tony Lindgren [mailto:tony@atomide.com] > >> > >> * Roger Quadros <rogerq@ti.com> [140516 05:23]: > >>> On 05/16/2014 02:03 PM, Pekon Gupta wrote: > >>>> +&gpmc { > >>>> + status = "okay"; > >>>> + pinctrl-names = "default"; > >>>> + pinctrl-0 = <&nand_flash_x8>; > >>>> + ranges = <0 0 0 0x01000000>; /* minimum GPMC partition = 16MB */ > >>>> + nand@0,0 { > >>>> + reg = <0 0 0x37c>; /* device IO registers */ > >>> > >>> This register space is used by the parent GPMC node as well as the NAND controller. So doing a > >> request_and_ioremap() on this space will fail as it is already taken by the GPMC driver. > >>> > >>> Further, the GPMC register space doesn't map to the GPMC memory map created by this Chip select > >> but it is mapped to L3_IO space. i.e. (physical address 0x6e00 0000) > >>> > >>> We could have split the GPMC register space into GPMC part and NAND part but to add to the > >> complexity, the register spaces for GPMC vs NAND are interleaved so it can't be easily split up. The way > >> the NAND driver is currently written is that it expects the register addresses to come via platform data, > >> primarily to get around this address interleaving issue. > >>> > >>> Apart from the GPMC register space, the NAND controller uses 4 bytes of GPMC memory map for > >> I/O, and that is something that could be reflected here. > >>> > >>> e.g. > >>> reg = <0 0 4>; /* NAND I/O space */ > >> > >> Guys, the reg size here is size of the IO region for the > >> NAND driver, it should not have anything to do with the GPMC > >> registers for the GPMC functions that the NAND driver may call. > >> > >> So it sounds like 0x37c is wrong, and 4 is the right value if > >> the NAND chip has only one IO register. > >> > > Yes, Roger and myself both agree on the actual size of 4. > > But what I'm not sure is what should be offset for a io-remapped region. > > > > Apologies for my ignorance here, as I'm not good in this memory mapping concept.. > > - I understand that for 'memory mapped' device <offset> is with respect to > > base-address of chip-select. > > - But for indirectly mapped device (like NAND) how is <offset> calculated? > > This would depend on what the NAND driver expects. In the current OMAP nand driver it expects only the memory mapped NAND I/O resource. > > > Example: For CS0 in GPMC .. > > GPMC_NAND_COMMAND_0 = 0x007c > > GPMC_NAND_ADDRESS_0 = 0x0080 > > GPMC_NAND_DATA_0 = 0x0084 > > OK, let's say that we want to update that NAND driver to accept a second memory resource which would be the GPMC registers starting from GPMC_NAND_COMMAND_0 (phy.addr 0x6e00 007c), then we need to define a new address in the ranges property of the gpmc node. > > Something like so > > ranges = <0 0 0x00000000 0x01000000 /* GPMC external map */ > 1 0 0x6e000000 0x0000037c>; /* GPMC register map */ > nand@0,0 { > reg = <0 0 4 /* NAND I/O space */ > 1 0x7c 3> /* NAND controller registers */ > > Since range 1 started from 0x6e000000 we specify offset as 0x7c. > > But at the moment the NAND driver doesn't directly access the GPMC register map so it should be sufficient to just specify the I/O space. > > > > > (1) Now, should the 'offset' for <reg> property used for NAND node > > connected at CS=0. reg = <0 ?? 4> > > (a) Should it be equal to 'GPMC_NAND_ADDRESS_0'? > > OR > > (b) There is no relation between 'GPMC register' and 'NAND partition' offset? > > > > (2) If considering (a) then should size consider only GPMC_NAND_ADDRESS_0 > > or also include GPMC_NAND_COMMAND_0 and GPMC_NAND_DATA_0? > > > > This is why I used the size of complete GPMC register space for NAND region also. The NAND driver should only ioremap the NAND register(s). The GPMC driver has the GPMC registers ioremapped, and should allow the NAND driver to use those registers via some functions in the GPMC code. Those functions should be ideally made available to the NAND driver by some Linux generic framework rather than custom exported functions. > >>> But still, the start address can't be 0 and has to be assigned when this CS region is mapped. It is still > >> unclear to me how that can be done. > >> > >> If the offset for the NAND driver needs to be different from 0, > >> it can be in the offset. For example, the smsc,lan91c94 driver > >> wants the IO address space to be at offset 0x300 to avoid some > >> extra warnings during the boot. So for that, the reg entry is: > >> > >> reg = <1 0x300 0xf>; > >> > >> Where we have: > >> > >> 1 = chip select > >> 0x300 = offset of smsc device register IO space from the start of > >> 16MB minimum GPMC partition > > > > This is where my confusion lies, where is the 0x300 coming from? > > Is this the offset of I/O register in given Ethernet IP register space? > > I'm not sure about 0x300 but this is my guess. > The smsc register addresses start at 0x300. In theory this could be aligned to the CS start address and we could have worked with 0 offset. But because of the 16MB min. granularity requirement for the GPMC CS start address, A23:A0 have to be 0. As CS start address can never be aligned to 0x300 we can't have 0 offset. The 0x300 is just a legacy requirement by the smc91x.c driver where it does some checking of the addresses. It still works just fine if 0x300 is set to 0, but will warn about the address space. Regards, Tony -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/arm/boot/dts/am437x-gp-evm.dts b/arch/arm/boot/dts/am437x-gp-evm.dts index 30ace1b..97b71e6 100644 --- a/arch/arm/boot/dts/am437x-gp-evm.dts +++ b/arch/arm/boot/dts/am437x-gp-evm.dts @@ -150,6 +150,27 @@ 0x14c (PIN_INPUT_PULLDOWN | MUX_MODE7) >; }; + + nand_flash_x8: nand_flash_x8 { + pinctrl-single,pins = < + 0x26c(PIN_OUTPUT_PULLDOWN | MUX_MODE7) /* spi2_cs0.gpio/eMMCorNANDsel */ + 0x0 (PIN_INPUT | MUX_MODE0) /* gpmc_ad0.gpmc_ad0 */ + 0x4 (PIN_INPUT | MUX_MODE0) /* gpmc_ad1.gpmc_ad1 */ + 0x8 (PIN_INPUT | MUX_MODE0) /* gpmc_ad2.gpmc_ad2 */ + 0xc (PIN_INPUT | MUX_MODE0) /* gpmc_ad3.gpmc_ad3 */ + 0x10 (PIN_INPUT | MUX_MODE0) /* gpmc_ad4.gpmc_ad4 */ + 0x14 (PIN_INPUT | MUX_MODE0) /* gpmc_ad5.gpmc_ad5 */ + 0x18 (PIN_INPUT | MUX_MODE0) /* gpmc_ad6.gpmc_ad6 */ + 0x1c (PIN_INPUT | MUX_MODE0) /* gpmc_ad7.gpmc_ad7 */ + 0x70 (PIN_INPUT_PULLUP | MUX_MODE0) /* gpmc_wait0.gpmc_wait0 */ + 0x74 (PIN_OUTPUT_PULLUP | MUX_MODE7) /* gpmc_wpn.gpmc_wpn */ + 0x7c (PIN_OUTPUT | MUX_MODE0) /* gpmc_csn0.gpmc_csn0 */ + 0x90 (PIN_OUTPUT | MUX_MODE0) /* gpmc_advn_ale.gpmc_advn_ale */ + 0x94 (PIN_OUTPUT | MUX_MODE0) /* gpmc_oen_ren.gpmc_oen_ren */ + 0x98 (PIN_OUTPUT | MUX_MODE0) /* gpmc_wen.gpmc_wen */ + 0x9c (PIN_OUTPUT | MUX_MODE0) /* gpmc_be0n_cle.gpmc_be0n_cle */ + >; + }; }; &i2c0 { @@ -246,3 +267,90 @@ phy_id = <&davinci_mdio>, <0>; phy-mode = "rgmii"; }; + +&elm { + status = "okay"; +}; + +&gpmc { + status = "okay"; + pinctrl-names = "default"; + pinctrl-0 = <&nand_flash_x8>; + ranges = <0 0 0 0x01000000>; /* minimum GPMC partition = 16MB */ + nand@0,0 { + reg = <0 0 0x37c>; /* device IO registers */ + ti,nand-ecc-opt = "bch8"; + ti,elm-id = <&elm>; + nand-bus-width = <8>; + gpmc,device-width = <1>; + gpmc,sync-clk-ps = <0>; + gpmc,cs-on-ns = <0>; + gpmc,cs-rd-off-ns = <40>; + gpmc,cs-wr-off-ns = <40>; + gpmc,adv-on-ns = <0>; + gpmc,adv-rd-off-ns = <25>; + gpmc,adv-wr-off-ns = <25>; + gpmc,we-on-ns = <0>; + gpmc,we-off-ns = <20>; + gpmc,oe-on-ns = <3>; + gpmc,oe-off-ns = <30>; + gpmc,access-ns = <30>; + gpmc,rd-cycle-ns = <40>; + gpmc,wr-cycle-ns = <40>; + gpmc,wait-pin = <0>; + gpmc,wait-on-read; + gpmc,wait-on-write; + gpmc,bus-turnaround-ns = <0>; + gpmc,cycle2cycle-delay-ns = <0>; + gpmc,clk-activation-ns = <0>; + gpmc,wait-monitoring-ns = <0>; + gpmc,wr-access-ns = <40>; + gpmc,wr-data-mux-bus-ns = <0>; + /* MTD partition table */ + /* All SPL-* partitions are sized to minimal length + * which can be independently programmable. For + * NAND flash this is equal to size of erase-block */ + #address-cells = <1>; + #size-cells = <1>; + partition@0 { + label = "NAND.SPL"; + reg = <0x00000000 0x00040000>; + }; + partition@1 { + label = "NAND.SPL.backup1"; + reg = <0x00040000 0x00040000>; + }; + partition@2 { + label = "NAND.SPL.backup2"; + reg = <0x00080000 0x00040000>; + }; + partition@3 { + label = "NAND.SPL.backup3"; + reg = <0x000c0000 0x00040000>; + }; + partition@4 { + label = "NAND.u-boot-spl-os"; + reg = <0x00100000 0x00080000>; + }; + partition@5 { + label = "NAND.u-boot"; + reg = <0x00180000 0x00100000>; + }; + partition@6 { + label = "NAND.u-boot-env"; + reg = <0x00280000 0x00040000>; + }; + partition@7 { + label = "NAND.u-boot-env.backup1"; + reg = <0x002c0000 0x00040000>; + }; + partition@8 { + label = "NAND.kernel"; + reg = <0x00300000 0x00700000>; + }; + partition@9 { + label = "NAND.file-system"; + reg = <0x00a00000 0x1f600000>; + }; + }; +};
Adds pinmux and DT node for Micron (MT29F4G08AB) x8 NAND device present on am437x-gp-evm board. (1) As NAND Flash data lines are muxed with eMMC, Thus at a given time either eMMC or NAND can be enabled. Selection between eMMC and NAND is controlled: (a) By dynamically driving following GPIO pin from software SPI2_CS0(GPIO) == 0 NAND is selected (default) SPI2_CS0(GPIO) == 1 eMMC is selected (b) By statically using Jumper (J89) on the board (2) As NAND device connnected to this board has page-size=4K and oob-size=224, So ROM code expects boot-loaders to be flashed in BCH16 ECC scheme for NAND boot. Signed-off-by: Pekon Gupta <pekon@ti.com> Reviewed-by: Javier Martinez Canillas <javier@dowhile0.org> --- arch/arm/boot/dts/am437x-gp-evm.dts | 108 ++++++++++++++++++++++++++++++++++++ 1 file changed, 108 insertions(+)