mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-05-02 05:07:46 -04:00
d888e9d783
Pinmuxing for DRA7x/AM57x family of processors need to be done in IO isolation as part of initial bootloader executed from SRAM. This is done as part of iodelay configuration sequence and is required due to the limitations introduced by erratum ID: i869[1] (IO Glitches can occur when changing IO settings) and elaborated in the Technical Reference Manual[2] 18.4.6.1.7 Isolation Requirements. Only peripheral that is permitted for dynamic pin mux configuration is MMC and DCAN. MMC is permitted to change to accommodate the requirements for varied speeds (which require IO-delay support in kernel as well). DCAN is a result of i893[1] (DCAN initialization sequence). DCAN pinmux is retained in this patch. MMC pinmux is missing from the dra7-evm.dts file and the board is relying on configuration done by bootloader. A subsequent patch will add MMC pinmux configuration. A side-effect of this patch is that NAND support is removed. NAND pins clash with VOUT3 on DRA7-EVM. U-Boot selects VOUT3 over NAND as per TI EVM application needs. [1] http://www.ti.com/lit/pdf/sprz429 [2] http://www.ti.com/lit/pdf/sprui30 Signed-off-by: Sekhar Nori <nsekhar@ti.com> Signed-off-by: Tony Lindgren <tony@atomide.com>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.