On 08/01/2016 09:41 AM, Stephen Warren wrote:
On 07/31/2016 07:02 PM, Simon Glass wrote:
On 27 July 2016 at 15:24, Stephen Warren <swar...@wwwdotorg.org> wrote:
From: Stephen Warren <swar...@nvidia.com>
The Tegra BPMP (Boot and Power Management Processor) is a separate
auxiliary CPU embedded into Tegra to perform power management work, and
controls related features such as clocks, resets, power domains, PMIC
I2C
bus, etc. This driver provides the core low-level communication path by
which feature-specific drivers (such as clock) can make requests to the
BPMP. This driver is similar to an MFD driver in the Linux kernel. It is
unconditionally selected by CONFIG_TEGRA186 since virtually any Tegra186
build of U-Boot will need the feature.
diff --git a/arch/arm/include/asm/arch-tegra/bpmp_abi.h
+static ulong tegra186_bpmp_get_shmem(struct udevice *dev, int index)
+{
+ int ret;
+ struct fdtdec_phandle_args args;
+ struct udevice fakedev;
+ fdt_addr_t reg;
+
+ ret = fdtdec_parse_phandle_with_args(gd->fdt_blob,
dev->of_offset,
+ "shmem", NULL, 0,
index, &args);
+ if (ret < 0) {
+ error("fdtdec_parse_phandle_with_args() failed:
%d\n", ret);
+ return ret;
+ }
+
+ fakedev.of_offset = args.node;
+ reg = dev_get_addr_index(&fakedev, 0);
This is nasty. If you don't set fakedev.parent, how does this work?
Hmmm. Good question; I thought dev_get_addr_index() only used the
device's own of_offset, but it does look like it uses the parent device
too. I'll have to look into this.
How sad. It works because dev->parent happens to be 0, and address 0 is
part of the mapped MMIO space so is mapped in the MMU, and then
dev->parent->of_offset happens to be 0, so dev_get_addr_index() ends up
querying #address-calls/#size-cells from the root node, and those happen
to match the values for the node we're actually interested in:-(
I guess the simplest approach is to use
fdtdec_get_addr_size_auto_parent() or similar as you say, but also call
fdt_translate_address() afterwards.
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