Hi Jon, I'm working on a similar memory controller for plat-orion. I have a few questions about your approach. On Wed, Feb 13, 2013 at 03:07:06PM -0600, Jon Hunter wrote: > > On 02/07/2013 03:51 AM, Mark Jackson wrote: > > Okay ... I have made some progress, but it's not ideal. > > > > Currently I've hacked the GPMC DT driver (gpmc_probe_dt(), etc) so it now handles setting up the > > chip selects and timings for NOR devices, e.g. > > > > gpmc: gpmc@50000000 { > > status = "okay"; > > ranges = <0 0 0x08000000 0x08000000>; /* CS0: NOR 16M */ > > Is that really 16M? Looks more like 128M :-) > > > nor@0,0 { > > compatible = "spansion,s29gl064n90t", "cfi-flash"; > > reg = <0 0 0>; > > I think that cfi-flash is expecting a length here. Here is > what I have ... > > +&gpmc { > + ranges = <0 0 0x08000000 0x04000000>; > + > + nor@0,0 { > + compatible = "cfi-flash"; > + linux,mtd-name= "intel,ge28f256l18b85"; > + #address-cells = <1>; > + #size-cells = <1>; > + reg = <0 0 0x04000000>; > + bank-width = <2>; > + > + partition@0 { > + label = "bootloader"; > + reg = <0 0x20000>; > + }; > + partition@0x20000 { > + label = "params"; > + reg = <0x20000 0x20000>; > + }; > + partition@0x40000 { > + label = "kernel"; > + reg = <0x40000 0x200000>; > + }; > + partition@0x240000 { > + label = "file-system"; > + reg = <0x240000 0x3dc0000>; > + }; > + }; > > > nor-flash@08000000 { > > compatible = "spansion,s29gl064n90t", "cfi-flash"; > > reg = <0x08000000 0x00800000>; > > bank-width = <2>; > > }; > > You don't need this extra entry if you add "simple-bus" to > the gpmc node compatible string. > That would be nice. However, I wonder what happens if cfi-flash probing fails: will the gpmc cs request by undone? See below... > + gpmc: gpmc@6800a000 { > + compatible = "ti,omap2420-gpmc", "simple-bus"; > + ti,hwmods = "gpmc"; > + reg = <0x6800a000 0x1000>; > + interrupts = <20>; > + > + gpmc,num-cs = <8>; > + gpmc,num-waitpins = <4>; > + #address-cells = <2>; > + #size-cells = <1>; > + }; > > Currently I have the following and this is working for me. > Please note that on my board the bootloader is configuring > the timings for me and so this is missing from the below > implementation and still needs to be added. > > Cheers > Jon > > From c0ede833fad704ab452b116154177e3a59166c7e Mon Sep 17 00:00:00 2001 > From: Jon Hunter <jon-hunter@xxxxxx> > Date: Fri, 8 Feb 2013 16:46:13 -0600 > Subject: [PATCH] ARM: OMAP2+: Add device-tree support for NOR flash > > --- > arch/arm/mach-omap2/gpmc.c | 69 ++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 69 insertions(+) > > diff --git a/arch/arm/mach-omap2/gpmc.c b/arch/arm/mach-omap2/gpmc.c > index bc90155..421320b 100644 > --- a/arch/arm/mach-omap2/gpmc.c > +++ b/arch/arm/mach-omap2/gpmc.c > @@ -26,6 +26,7 @@ > #include <linux/interrupt.h> > #include <linux/platform_device.h> > #include <linux/of.h> > +#include <linux/of_address.h> > #include <linux/of_mtd.h> > #include <linux/of_device.h> > #include <linux/mtd/nand.h> > @@ -517,6 +518,26 @@ static int gpmc_cs_delete_mem(int cs) > return r; > } > > +static int gpmc_cs_remap(int cs, u32 base) > +{ > + int r; > + u32 old_base, size; > + > + gpmc_cs_get_memconf(cs, &old_base, &size); > + if (base == old_base) > + return 0; > + gpmc_cs_disable_mem(cs); > + r = gpmc_cs_delete_mem(cs); > + if (IS_ERR_VALUE(r)) > + return r; > + r = gpmc_cs_insert_mem(cs, base, size); > + if (IS_ERR_VALUE(r)) > + return r; > + gpmc_cs_enable_mem(cs, base, size); > + > + return 0; > +} > + > int gpmc_cs_request(int cs, unsigned long size, unsigned long *base) > { > struct resource *res = &gpmc_cs_mem[cs]; > @@ -1305,6 +1326,45 @@ static int gpmc_probe_onenand_child(struct platform_device *pdev, > } > #endif > > +static int gpmc_probe_nor_child(struct platform_device *pdev, > + struct device_node *child) > +{ > + struct resource res; > + unsigned long base; > + int rc, cs; > + > + if (of_property_read_u32(child, "reg", &cs) < 0) { > + dev_err(&pdev->dev, "%s has no 'reg' property\n", > + child->full_name); > + return -ENODEV; > + } > + > + if (of_address_to_resource(child, 0, &res)) { > + dev_err(&pdev->dev, "%s has malformed 'reg' property\n", > + child->full_name); > + return -ENODEV; > + } > + > + rc = gpmc_cs_request(cs, res.end - res.start, &base); > + if (rc < 0) > + pr_err("%s: cannot request GPMC CS %d\n", __func__, cs); gpmc_cs_request will request a memory region from the resource allocator using allocate_resource(). How will this be released in case cfi-flash probe fails? IMHO, this works fine currently for NAND and OneNAND because we register the platform device explicitly and, thus, know if that fails. > + > + /* > + * gpmc_cs_request() will map the CS to an arbitary location > + * in the gpmc address space. When booting with device-tree we > + * want the NOR flash to be mapped to the location specified > + * in the device-tree blob. So remap the CS to this location. > + */ > + rc = gpmc_cs_remap(cs, res.start); > + if (rc < 0) { > + pr_err("%s: cannot remap GPMC CS %d to 0x%x\n", > + __func__, cs, res.start); > + gpmc_cs_free(cs); > + } > + > + return rc; > +} > + > static int gpmc_probe_dt(struct platform_device *pdev) > { > int ret; > @@ -1330,6 +1390,15 @@ static int gpmc_probe_dt(struct platform_device *pdev) > return ret; > } > } > + > + for_each_node_by_name(child, "nor") { > + ret = gpmc_probe_nor_child(pdev, child); > + if (ret < 0) { > + of_node_put(child); > + return ret; > + } > + } > + > return 0; > } > #else > -- Thanks, -- Ezequiel García, Free Electrons Embedded Linux, Kernel and Android Engineering http://free-electrons.com -- 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