Hi Boris,
Thank you very much for the review comments and your time...
On 30/4/2020 9:01 pm, Boris Brezillon wrote:
On Thu, 30 Apr 2020 14:36:00 +0200
Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx> wrote:
On Thu, 30 Apr 2020 17:07:03 +0800
"Ramuthevar, Vadivel MuruganX"
<vadivel.muruganx.ramuthevar@xxxxxxxxxxxxxxx> wrote:
The question is, is it the same value we have in nand_pa or it is
different?
Different address which is 0xE1400000 NAND_BASE_PHY address.
Then why didn't you tell me they didn't match when I suggested to pass
sorry, because you keep asking nand_pa after that only I realized that.
nand_pa? So now the question is, what does this address represent?
EBU-MODULE
_________ _______________________
| | | |NAND CTRL |
| FPI BUS |==>| CS0(0x174) | 0xE100 ( 0xE14/0xE1C) NAND_PHY_BASE
|_________| |_CS1(0x17C)_|__________ |
EBU_CONRTROLLER_BASE : 0xE0F0_0000
HSNAND_BASE: 0xE100_0000
NAND_CS0: 0xE140_0000
NAND_CS1: 0xE1C0_0000
MEM_REGION_BASE_CS0: 0x17400 (internal to ebu controller )
MEM_REGION_BASE_CS1: 0x17C00
Hm, I wonder if we shouldn't use a 'ranges' property to describe this
address translation. Something like
ebu@xxx {
ranges = <0x17400000 0xe1400000 0x1000>,
<0x17c00000 0xe1c00000 0x1000>;
reg = <0x17400000>, <0x17c00000>;
reg-names = "cs-0", "cs-1";
}
The translated address (0xE1X00000) will be available in res->start,
and the non-translated one (0x17X00000) can be retrieved with
of_get_address(). All you'd have to do then would be calculate the
mask:
mask = (translated_address & original_address) >> 22;
num_comp_bits = fls(mask);
WARN_ON(mask != GENMASK(num_comp_bits - 1, 0));
Which allows you to properly set the ADDR_SEL() register without
relying on some hardcoded values:
writel(original_address | EBU_ADDR_SEL_REGEN |
EBU_ADDR_COMP_BITS(num_comp_bits),
ebu_host->ebu + EBU_ADDR_SEL(csid));
That's quite important if we want to merge the xway NAND driver with
this one.
Looks like the translation is done at the FPI bus declaration level (see
[1]). We really need to see the big picture to take a wise decision
about the bindings. Would you mind pasting your dsti/dts files
somewhere? It feels like the NAND controller is a sub-part of a more
generic 'memory' controller, in which case the NAND controller should be
declared as a child of this generic memory bus (called localbus in [1],
but maybe EBU is more accurate).
[1]https://github.com/xieyaxiongfly/Atheros_CSI_tool_OpenWRT_src/blob/master/target/linux/lantiq/files-4.14/arch/mips/boot/dts/vr9.dtsi#L162
for the ebu-nand node in the dts file.
ebu_nand: ebu_nand@e0f00000 {
compatible = "intel,lgm-ebu-nand";
reg = <0xe0f00000 0x100 //EBU_NAND controller
0xe1000000 0x300 //NAND ECC Extension access
0xe1400000 0x80000
0xe1c00000 0x10000>;
reg-names = "ebunand", "hsnand", "nand_cs0", "nand_cs1";
dmas = <&dma0 8>, <&dma0 9>;
dma-names = "ebu_rx", "ebu_tx";
clocks = <&cgu0 LGM_GCLK_EBU>;
};
&ebu_nand {
status = "disabled";
nand,cs = <1>;
nand-ecc-mode = "hw";
pinctrl-names = "default";
pinctrl-0 = <&ebu_nand_base &ebu_cs1>;
};
This is not comes under fpi in our devicetree.
Regards
Vadivel
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