Subject: [PATCH v3 4/4] ARM: OMAP: gpmc: add DT bindings for GPMC timings and NAND

From: [email-masked] (Daniel Mack)
Date: Mon, 05 Nov 2012 13:58:22 +0100

On 05.11.2012 12:03, Philip, Avinash wrote:
> On Fri, Nov 02, 2012 at 20:55:56, Daniel Mack wrote:
>> This patch adds basic DT bindings for OMAP GPMC.
>>
>> The actual peripherals are instanciated from child nodes within the GPMC
>> node, and the only type of device that is currently supported is NAND.
>>
>> Code was added to parse the generic GPMC timing parameters and some
>> documentation with examples on how to use them.
>>
>> Successfully tested on an AM33xx board.
>>
>> Signed-off-by: Daniel Mack <[email-masked]>
> [...]
>> +
>> +		nand at 0,0 {
>> +			reg = <0 0 0>; /* CS0, offset 0 */
>> +			nand-bus-width = <16>;
>> +			nand-ecc-mode = "none";
>> +
>> +			gpmc,sync-clk = <0>;
>> +			gpmc,cs-on = <0>;
>> +			gpmc,cs-rd-off = <36>;
>> +			gpmc,cs-wr-off = <36>;
>> +			gpmc,adv-on = <6>;
>> +			gpmc,adv-rd-off = <24>;
>> +			gpmc,adv-wr-off = <36>;
>> +			gpmc,we-off = <30>;
>> +			gpmc,oe-off = <48>;
>> +			gpmc,access = <54>;
>> +			gpmc,rd-cycle = <72>;
>> +			gpmc,wr-cycle = <72>;
>> +			gpmc,wr-access = <30>;
>> +			gpmc,wr-data-mux-bus = <0>;
>> +
>> +			#address-cells = <1>;
>> +			#size-cells = <1>;
>> +
> 
> Can you take the timings (for example) from arago tree. The timings is tested in am335x-evm
> So the timings can be directly used to populate GPMC timings. Timings can found at
> 
> http://arago-project.org/git/projects/?p=linux-am33x.git;a=commitdiff;
> h=66bfbd2c5b35dc81edce0c24843c476161ab5978;hp=370630359cb8db711cf0941cd2a242e28ccfb61e
> 
> [...]
>> +static int gpmc_probe_dt(struct platform_device *pdev)
> 
> Can you take care of the following section mismatch.
> WARNING: vmlinux.o(.text+0x1e2d0): Section mismatch in reference
> from the function gpmc_probe_dt() to the function .init.text:gpmc_nand_init().

Sore, both fixed for v4.

> [...]
>> +
>> +		val = of_get_nand_ecc_mode(child);
>> +		if (val >= 0)
>> +			gpmc_nand_data->ecc_opt = val;
> 
> This will fail for BCH. Index of "soft_bch" is 5 & also don't have selection
> option between for BCH4 & BCH8 also.
> Can you use the of_property_read_u32 (as done early) to pass the ecc selection
> from dt file. This will help selection of BCH4 & BCH8 ecc options.

Hmm. Shouldn't we rather teach of_get_nand_ecc_mode() that two modes and
bring the enum in sync?

Daniel