On 04/17/2013 11:40 AM, Lars Poeschel wrote:
> Hi Javier!
>
> On Thursday 14 March 2013 at 22:54:11, Javier Martinez Canillas wrote:
>> Besides being used to interface with external memory devices,
>> the General-Purpose Memory Controller can be used to connect
>> Pseudo-SRAM devices such as ethernet controllers to OMAP2+
>> processors using the TI GPMC as a data bus.
>>
>> This patch allows an ethernet chip to be defined as an GPMC
>> child device node.
>>
>> Signed-off-by: Javier Martinez Canillas
>> <javier.martinez@xxxxxxxxxxxxxxx>
>>
>> ---
>> Changes since v2:
>> - remove optional #address-cells and #size-cells since are not
>> relevant for ethernet chips; suggested by Jon Hunter.
>>
>> Changes since v1:
>> - Improve the DT binding documentation explaining that even when the
>> GPMC maximum bus address width is 16-bit, it supports devices with
>> 32-bit registers address width and the device property especifying this
>> has to be set accordingly; suggested by Jon Hunter.
>>
>> Documentation/devicetree/bindings/net/gpmc-eth.txt | 97
>> ++++++++++++++++++++ arch/arm/mach-omap2/gpmc.c
>> | 8 ++
>> 2 files changed, 105 insertions(+), 0 deletions(-)
>> create mode 100644 Documentation/devicetree/bindings/net/gpmc-eth.txt
>>
>> diff --git a/Documentation/devicetree/bindings/net/gpmc-eth.txt
>> b/Documentation/devicetree/bindings/net/gpmc-eth.txt new file mode
>> 100644
>> index 0000000..24cb4e4
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/net/gpmc-eth.txt
>> @@ -0,0 +1,97 @@
>> +Device tree bindings for Ethernet chip connected to TI GPMC
>> +
>> +Besides being used to interface with external memory devices, the
>> +General-Purpose Memory Controller can be used to connect Pseudo-SRAM
>> devices +such as ethernet controllers to processors using the TI GPMC
>> as a data bus. +
>> +Ethernet controllers connected to TI GPMC are represented as child
>> nodes of +the GPMC controller with an "ethernet" name.
>> +
>> +All timing relevant properties as well as generic GPMC child properties
>> are +explained in a separate documents. Please refer to
>> +Documentation/devicetree/bindings/bus/ti-gpmc.txt
>> +
>> +For the properties relevant to the ethernet controller connected to the
>> GPMC +refer to the binding documentation of the device. For example,
>> the documentation +for the SMSC 911x is
>> Documentation/devicetree/bindings/net/smsc911x.txt +
>> +Child nodes need to specify the GPMC bus address width using the
>> "bank-width" +property but is possible that an ethernet controller also
>> has a property to +specify the I/O registers address width. Even when
>> the GPMC has a maximum 16-bit +address width, it supports devices with
>> 32-bit word registers. +For example with an SMSC LAN911x/912x
>> controller connected to the TI GPMC on an +OMAP2+ board, "bank-width =
>> <2>;" and "reg-io-width = <4>;".
>> +
>> +Required properties:
>> +- bank-width: Address width of the device in bytes. GPMC supports
>> 8-bit + and 16-bit devices and so must be either 1 or 2 bytes.
>> +- compatible: Compatible string property for the ethernet child
>> device. +- gpmc,cs-on: Chip-select assertion time
>> +- gpmc,cs-rd-off: Chip-select de-assertion time for reads
>> +- gpmc,cs-wr-off: Chip-select de-assertion time for writes
>> +- gpmc,oe-on: Output-enable assertion time
>> +- gpmc,oe-off Output-enable de-assertion time
>> +- gpmc,we-on: Write-enable assertion time
>> +- gpmc,we-off: Write-enable de-assertion time
>> +- gpmc,access: Start cycle to first data capture (read access)
>> +- gpmc,rd-cycle: Total read cycle time
>> +- gpmc,wr-cycle: Total write cycle time
>> +- reg: Chip-select, base address (relative to chip-select)
>> + and size of the memory mapped for the device.
>> + Note that base address will be typically 0 as this
>> + is the start of the chip-select.
>> +
>> +Optional properties:
>> +- gpmc,XXX Additional GPMC timings and settings parameters. See
>> + Documentation/devicetree/bindings/bus/ti-gpmc.txt
>> +
>> +Example:
>> +
>> +gpmc: gpmc@6e000000 {
>> + compatible = "ti,omap3430-gpmc";
>> + ti,hwmods = "gpmc";
>> + reg = <0x6e000000 0x1000>;
>> + interrupts = <20>;
>> + gpmc,num-cs = <8>;
>> + gpmc,num-waitpins = <4>;
>> + #address-cells = <2>;
>> + #size-cells = <1>;
>> +
>> + ranges = <5 0 0x2c000000 0x1000000>;
>> +
>> + ethernet@5,0 {
>> + compatible = "smsc,lan9221", "smsc,lan9115";
>> + reg = <5 0 0xff>;
>> + bank-width = <2>;
>> +
>> + gpmc,mux-add-data;
>> + gpmc,cs-on = <0>;
>> + gpmc,cs-rd-off = <186>;
>> + gpmc,cs-wr-off = <186>;
>> + gpmc,adv-on = <12>;
>> + gpmc,adv-rd-off = <48>;
>> + gpmc,adv-wr-off = <48>;
>> + gpmc,oe-on = <54>;
>> + gpmc,oe-off = <168>;
>> + gpmc,we-on = <54>;
>> + gpmc,we-off = <168>;
>> + gpmc,rd-cycle = <186>;
>> + gpmc,wr-cycle = <186>;
>> + gpmc,access = <114>;
>> + gpmc,page-burst-access = <6>;
>> + gpmc,bus-turnaround = <12>;
>> + gpmc,cycle2cycle-delay = <18>;
>> + gpmc,wr-data-mux-bus = <90>;
>> + gpmc,wr-access = <186>;
>> + gpmc,cycle2cycle-samecsen;
>> + gpmc,cycle2cycle-diffcsen;
>> +
>> + interrupt-parent = <&gpio6>;
>> + interrupts = <16>;
>> + vmmc-supply = <&vddvario>;
>> + vmmc_aux-supply = <&vdd33a>;
>> + reg-io-width = <4>;
>> +
>> + smsc,save-mac-address;
>> + };
>> +};
>> diff --git a/arch/arm/mach-omap2/gpmc.c b/arch/arm/mach-omap2/gpmc.c
>> index 898b44d..2bc276b 100644
>> --- a/arch/arm/mach-omap2/gpmc.c
>> +++ b/arch/arm/mach-omap2/gpmc.c
>> @@ -1559,6 +1559,14 @@ static int gpmc_probe_dt(struct platform_device
>> *pdev) }
>> }
>>
>> + for_each_node_by_name(child, "ethernet") {
>> + ret = gpmc_probe_generic_child(pdev, child);
>> + if (ret < 0) {
>> + of_node_put(child);
>> + return ret;
>> + }
>> + }
>> +
>> return 0;
>> }
>> #else
>
> I did a little testing on my am335x based device and this patch does
> introduce a problem for me. I am not sure if it is indeed related to this
> patch or if I created my device tree the wrong way. Maybe you can help a
> bit. Here are the relevant parts of kernel booting up:
>
> ...
>
> [ 0.136054] OMAP GPIO hardware version 0.1
> [ 0.139081] platform 481cc000.d_can: alias fck already exists
> [ 0.141593] omap-gpmc 50000000.gpmc: GPMC revision 6.0
> [ 0.141978] omap-gpmc 50000000.gpmc: cannot request GPMC CS 1242562560
> [ 0.141997] omap-gpmc 50000000.gpmc: failed to probe DT parameters
> [ 0.147869] bio: create slab <bio-0> at 0
> [ 0.162814] omap-dma-engine omap-dma-engine: OMAP DMA engine driver
>
> ...
>
> [ 1.013897] brd: module loaded
> [ 1.020964] loop: module loaded
> [ 1.024535] at24 0-0056: 512 byte 24c04 EEPROM, writable, 128
> bytes/write
> [ 1.049607] Unable to handle kernel NULL pointer dereference at virtual
> address 000001a4
> [ 1.058086] pgd = c0004000
> [ 1.060942] [000001a4] *pgd=00000000
> [ 1.064700] Internal error: Oops: 805 [#1] ARM
> [ 1.069350] Modules linked in:
> [ 1.072557] CPU: 0 Not tainted (3.9.0-rc1 #27)
> [ 1.077600] PC is at omap_hwcontrol+0x44/0x4c
> [ 1.082173] LR is at nand_command+0x64/0x204
> [ 1.086650] pc : [<c0297430>] lr : [<c0293294>] psr: 00000113
> [ 1.086650] sp : df059db8 ip : 00000000 fp : 00000001
> [ 1.098680] r10: c05dffe0 r9 : df059e10 r8 : ffffffff
> [ 1.104183] r7 : df25ea38 r6 : 00000005 r5 : 00000090 r4 : df25e810
> [ 1.111024] r3 : 000001a4 r2 : 00000085 r1 : 00000000 r0 : df25e800
> [ 1.117858] Flags: nzcv IRQs on FIQs on Mode SVC_32 ISA ARM Segment
> kernel
> [ 1.125514] Control: 10c5387d Table: 80004019 DAC: 00000015
> [ 1.131532] Process swapper (pid: 1, stack limit = 0xdf058238)
> [ 1.137637] Stack: (0xdf059db8 to 0xdf05a000)
> [ 1.142213] 9da0:
> df25ea38 df25e810
> [ 1.150788] 9dc0: 00000000 00000000 00000000 df059e10 c05dffe0 c0293764
> 00000000 e0832000
> [ 1.159357] 9de0: 08000000 00001000 00000000 c05c85d4 08000fff c0015308
> 00000000 00000004
> [ 1.167928] 9e00: 00000000 c05dffd0 df0d5ed0 00000000 0000008f c05dffe0
> 00000000 df25e800
> [ 1.176500] 9e20: c062b78c df25e810 df0d5ed0 00000000 0000008f c05dffe0
> 00000000 c0297944
> [ 1.185070] 9e40: 00000000 00000000 df059e70 df25d848 00000001 c00fee28
> c05dffe0 00000003
> [ 1.193637] 9e60: df00a62c c004f8cc 00000000 00000000 00000000 00000000
> c05e0014 c05dffe0
> [ 1.202209] 9e80: c05dffe8 c05dffe0 c062b170 c05e0014 00000000 c05f7c8c
> c05a40d8 c024da78
> [ 1.210783] 9ea0: c05dffe0 c024c78c c05dffe0 c05f7c8c c05e0014 00000000
> c0588360 c024c9ac
> [ 1.219354] 9ec0: c05f7c8c c024c920 df059ed0 c024b2ac df00a60c df0cf970
> df2585c0 c05f7c8c
> [ 1.227925] 9ee0: c05f25c0 df2585c0 00000000 c024b9c8 c0513f20 c062b788
> c05ae958 c05ae958
> [ 1.236495] 9f00: c05f7c8c df058000 00000000 c024cf90 c05ae958 c06049c0
> df058000 00000000
> [ 1.245070] 9f20: c0588360 c0008698 c0567ee4 c0a3cbe1 c0a3cbdc c05a40d8
> 00000000 c04db534
> [ 1.253650] 9f40: c05675f4 00000006 c0a3cbe6 00000006 00000000 c05ae958
> c05bac60 c06049c0
> [ 1.262227] 9f60: 00000007 c0588360 0000008f c05ae960 00000000 c0588290
> 00000006 00000006
> [ 1.270795] 9f80: c0588360 ff5c5cfb 00000000 c03ff488 00000000 00000000
> 00000000 00000000
> [ 1.279378] 9fa0: 00000000 c03ff490 00000000 c000e078 00000000 00000000
> 00000000 00000000
> [ 1.287944] 9fc0: 00000000 00000000 00000000 00000000 00000000 00000000
> 00000000 00000000
> [ 1.296529] 9fe0: 00000000 00000000 00000000 00000000 00000013 00000000
> dd5f5ddf 3d6ffed6
> [ 1.305120] [<c0297430>] (omap_hwcontrol+0x44/0x4c) from [<c0293294>]
> (nand_command+0x64/0x204)
> [ 1.314246] [<c0293294>] (nand_command+0x64/0x204) from [<c0293764>]
> (nand_scan_ident+0x70/0xc8c)
> [ 1.323553] [<c0293764>] (nand_scan_ident+0x70/0xc8c) from [<c0297944>]
> (omap_nand_probe+0x1dc/0x638)
> [ 1.333234] [<c0297944>] (omap_nand_probe+0x1dc/0x638) from [<c024da78>]
> (platform_drv_probe+0x18/0x1c)
> [ 1.343095] [<c024da78>] (platform_drv_probe+0x18/0x1c) from
> [<c024c78c>] (driver_probe_device+0x90/0x224)
> [ 1.353216] [<c024c78c>] (driver_probe_device+0x90/0x224) from
> [<c024c9ac>] (__driver_attach+0x8c/0x90)
> [ 1.363072] [<c024c9ac>] (__driver_attach+0x8c/0x90) from [<c024b2ac>]
> (bus_for_each_dev+0x68/0x8c)
> [ 1.372562] [<c024b2ac>] (bus_for_each_dev+0x68/0x8c) from [<c024b9c8>]
> (bus_add_driver+0x1bc/0x228)
> [ 1.382135] [<c024b9c8>] (bus_add_driver+0x1bc/0x228) from [<c024cf90>]
> (driver_register+0x78/0x14c)
> [ 1.391718] [<c024cf90>] (driver_register+0x78/0x14c) from [<c0008698>]
> (do_one_initcall+0x34/0x17c)
> [ 1.401304] [<c0008698>] (do_one_initcall+0x34/0x17c) from [<c0588290>]
> (kernel_init_freeable+0xdc/0x1ac)
> [ 1.411350] [<c0588290>] (kernel_init_freeable+0xdc/0x1ac) from
> [<c03ff490>] (kernel_init+0x8/0xe4)
> [ 1.420843] [<c03ff490>] (kernel_init+0x8/0xe4) from [<c000e078>]
> (ret_from_fork+0x14/0x3c)
> [ 1.429600] Code: e5c31000 e12fff1e f57ff04f e590349c (e5c31000)
> [ 1.436070] ---[ end trace 2af83d33cc671cfa ]---
> [ 1.440961] Kernel panic - not syncing: Attempted to kill init!
> exitcode=0x0000000b
>
> As you can see above, gpmc_probe fails. I digged a bit into it and this is
> because gpmc_probe_dt fails which in turn fails because
> gpmc_probe_generic_child in the "ethernet" part fails.
> The interesting part is that it finds an "ethernet" node. I did not
> configure one in the gpmc. am335x based devices include am33xx.dtsi in
> their device tree source. This file contains an "ethernet" node for the on-
> chip ethernet controller. Your code grabs this node and obviously fails to
> probe it. This is also where the strange CS value in the kernel output
> comes from (0x4a100000 == 1242562560). So I am not able to use the gpmc on
> any am33xx device because probing childs always fails.
> For reference here is the gpmc part of my device tree source:
>
> ocp {
>
> ...
>
> gpmc: gpmc@50000000 {
> compatible = "ti,am3352-gpmc";
> ti,hwmods = "gpmc";
> reg = <0x50000000 0x1000000>;
> interrupts = <100>;
>
> gpmc,num-cs = <7>;
> gpmc,num-waitpins = <2>;
> #address-cells = <2>;
> #size-cells = <1>;
> ranges = <0 0 0x08000000 0x20000000>; /* CS0 @addr 0x8000000, size
> 512MiB */
>
> nand@0,0 {
> reg = <0 0 0>; /* CS0, offset 0 */
> nand-bus-width = <8>;
> ti,nand-ecc-opt = "sw";
>
> gpmc,sync-clk = <0>;
> gpmc,cs-on = <0>;
> gpmc,cs-rd-off = <44>;
> gpmc,cs-wr-off = <44>;
> gpmc,adv-on = <6>;
> gpmc,adv-rd-off = <34>;
> gpmc,adv-wr-off = <44>;
> gpmc,we-off = <40>;
> gpmc,oe-off = <54>;
> gpmc,access = <64>;
> gpmc,rd-cycle = <82>;
> gpmc,wr-cycle = <82>;
> gpmc,wr-access = <40>;
> gpmc,wr-data-mux-bus = <0>;
>
> #address-cells = <1>;
> #size-cells = <1>;
>
> /* partitions go here */
> partition@0 {
> label = "u-boot";
> reg = <0x0000000 0x100000>;
> read-only;
> };
>
> uimage@100000 {
> label = "uImage";
> reg = <0x0100000 0x200000>;
> };
> };
> };
> };
>
> Is this a problem of my device tree ? If you need further information or if
> I can help debugging, let me know.
>
> Regards,
> Lars
>
Hi Lars,
Yes, in fact I just realized that for_each_node_by_name() expand to:
#define for_each_node_by_name(dn, name) \
for (dn = of_find_node_by_name(NULL, name); dn; \
dn = of_find_node_by_name(dn, name))
which means that it will search for a node with "name" on the complete
DeviceTree and this is wrong. It should only search on GPMC childs.
Could you please test the following patch? If it works for you I'll add a proper
description and submit it as a PATCH.
Thanks a lot and best regards,
Javier
>From d8dab9ae9a0284f17553875c2fddd806d9f6ab2e Mon Sep 17 00:00:00 2001
From: Javier Martinez Canillas <javier.martinez@xxxxxxxxxxxxxxx>
Date: Wed, 17 Apr 2013 13:50:30 +0200
Subject: [PATCH] ARM: OMAP2+: only search for GPMC DT child nodes on
probe
Signed-off-by: Javier Martinez Canillas <javier.martinez@xxxxxxxxxxxxxxx>
---
arch/arm/mach-omap2/gpmc.c | 51 ++++++++++++++++++++-----------------------
1 files changed, 24 insertions(+), 27 deletions(-)
diff --git a/arch/arm/mach-omap2/gpmc.c b/arch/arm/mach-omap2/gpmc.c
index ed946df..58e2415 100644
--- a/arch/arm/mach-omap2/gpmc.c
+++ b/arch/arm/mach-omap2/gpmc.c
@@ -1520,35 +1520,32 @@ static int gpmc_probe_dt(struct platform_device *pdev)
return ret;
}
- for_each_node_by_name(child, "nand") {
- ret = gpmc_probe_nand_child(pdev, child);
- if (ret < 0) {
- of_node_put(child);
- return ret;
- }
- }
-
- for_each_node_by_name(child, "onenand") {
- ret = gpmc_probe_onenand_child(pdev, child);
- if (ret < 0) {
- of_node_put(child);
- return ret;
- }
- }
+ for_each_child_of_node(pdev->dev.of_node, child) {
+ if (child->name) {
+ if (of_node_cmp(child->name, "nand") == 0) {
+ ret = gpmc_probe_nand_child(pdev, child);
+ if (ret < 0) {
+ of_node_put(child);
+ return ret;
+ }
+ }
- for_each_node_by_name(child, "nor") {
- ret = gpmc_probe_generic_child(pdev, child);
- if (ret < 0) {
- of_node_put(child);
- return ret;
- }
- }
+ if (of_node_cmp(child->name, "onenand") == 0) {
+ ret = gpmc_probe_onenand_child(pdev, child);
+ if (ret < 0) {
+ of_node_put(child);
+ return ret;
+ }
+ }
- for_each_node_by_name(child, "ethernet") {
- ret = gpmc_probe_generic_child(pdev, child);
- if (ret < 0) {
- of_node_put(child);
- return ret;
+ if (of_node_cmp(child->name, "ethernet") == 0 ||
+ of_node_cmp(child->name, "nor") == 0) {
+ ret = gpmc_probe_generic_child(pdev, child);
+ if (ret < 0) {
+ of_node_put(child);
+ return ret;
+ }
+ }
}
}
--
1.7.7.6
--
To unsubscribe from this list: send the line "unsubscribe linux-omap" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
