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Commit 023b13a5 authored by Benjamin Herrenschmidt's avatar Benjamin Herrenschmidt Committed by Michael Ellerman
Browse files

powerpc/powernv: Add support for direct mapped LPC on POWER9 



Use the new non-PCI ISA bridge support to expose the POWER9
LPC bus as direct mapped via the ISA IO port range. This
enables direct access via drivers such as 8250

Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent b3c711a9

arch/powerpc/kernel/legacy_serial.c

+2 −1
Original line number Diff line number Diff line
@@ -233,7 +233,8 @@ static int __init add_legacy_isa_port(struct device_node *np, 
	 *

	 * Note: Don't even try on P8 lpc, we know it's not directly mapped

	 */

	if (!of_device_is_compatible(isa_brg, "ibm,power8-lpc")) {

	if (!of_device_is_compatible(isa_brg, "ibm,power8-lpc") ||

	    of_get_property(isa_brg, "ranges", NULL)) {

		taddr = of_translate_address(np, reg);

		if (taddr == OF_BAD_ADDR)

			taddr = 0;

arch/powerpc/platforms/powernv/opal-lpc.c

+13 −5
Original line number Diff line number Diff line
@@ -407,9 +407,17 @@ void opal_lpc_init(void) 
	if (opal_lpc_chip_id < 0)

		return;



	/* Does it support direct mapping ? */

	if (of_get_property(np, "ranges", NULL)) {

		pr_info("OPAL: Found memory mapped LPC bus on chip %d\n",

			opal_lpc_chip_id);

		isa_bridge_init_non_pci(np);

	} else {

		pr_info("OPAL: Found non-mapped LPC bus on chip %d\n",

			opal_lpc_chip_id);



		/* Setup special IO ops */

		ppc_pci_io = opal_lpc_io;

		isa_io_special = true;



	pr_info("OPAL: Power8 LPC bus found, chip ID %d\n", opal_lpc_chip_id);

	}

}