Hi Ricardo, On Wed, Mar 14, 2018 at 4:54 AM Ricardo Ribalda Delgado < ricardo.ribalda@xxxxxxxxx> wrote: > Hi Daniel > On Wed, Mar 14, 2018 at 1:36 AM, Daniel Kurtz <djkurtz@xxxxxxxxxxxx> wrote: > > > > AMD Carrizo / Stoneyridge use a DesignWare 8250 UART that uses a 48 MHz > > input clock. > > > > Allow these platforms to set up this clock by specifying a kernel command > > line like: > > earlycon=amdcz,mmio32,0xfedc6000,115200 > If the port and the mode (mmio32) is always fixed, couldn't we just > add those two into > early_amdcz_setup? There are multiple memory mapped UARTs on at least the one chip I am aware of, specifying the address here chooses which port to use as the early console. In fact, the recommended way is to have firmware specify an ACPI SPCR table with OEMID="AMDCZ " (see https://patchwork.kernel.org/patch/10281307/) to configure proper access and address. With an SPCR table in place, the kernel command line just becomes "earlycon", with no parameters. -Dan -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
