From 5bddf92e689c0a3da57f4fd17b83d4eb1e436b80 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Tue, 4 May 2021 13:09:11 +0100 Subject: [PATCH] hw/misc/mps2-scc: Support using CFG0 bit 0 for remapping MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On some boards, SCC config register CFG0 bit 0 controls whether parts of the board memory map are remapped. Support this with: * a device property scc-cfg0 so the board can specify the initial value of the CFG0 register * an outbound GPIO line which tracks bit 0 and which the board can wire up to provide the remapping Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Reviewed-by: Philippe Mathieu-Daudé Message-id: 20210504120912.23094-3-peter.maydell@linaro.org --- hw/misc/mps2-scc.c | 13 ++++++++++--- include/hw/misc/mps2-scc.h | 9 +++++++++ 2 files changed, 19 insertions(+), 3 deletions(-) diff --git a/hw/misc/mps2-scc.c b/hw/misc/mps2-scc.c index c56aca86ad..b3b42a792c 100644 --- a/hw/misc/mps2-scc.c +++ b/hw/misc/mps2-scc.c @@ -23,6 +23,7 @@ #include "qemu/bitops.h" #include "trace.h" #include "hw/sysbus.h" +#include "hw/irq.h" #include "migration/vmstate.h" #include "hw/registerfields.h" #include "hw/misc/mps2-scc.h" @@ -186,10 +187,13 @@ static void mps2_scc_write(void *opaque, hwaddr offset, uint64_t value, switch (offset) { case A_CFG0: /* - * TODO on some boards bit 0 controls RAM remapping; - * on others bit 1 is CPU_WAIT. + * On some boards bit 0 controls board-specific remapping; + * we always reflect bit 0 in the 'remap' GPIO output line, + * and let the board wire it up or not as it chooses. + * TODO on some boards bit 1 is CPU_WAIT. */ s->cfg0 = value; + qemu_set_irq(s->remap, s->cfg0 & 1); break; case A_CFG1: s->cfg1 = value; @@ -283,7 +287,7 @@ static void mps2_scc_reset(DeviceState *dev) int i; trace_mps2_scc_reset(); - s->cfg0 = 0; + s->cfg0 = s->cfg0_reset; s->cfg1 = 0; s->cfg2 = 0; s->cfg5 = 0; @@ -308,6 +312,7 @@ static void mps2_scc_init(Object *obj) memory_region_init_io(&s->iomem, obj, &mps2_scc_ops, s, "mps2-scc", 0x1000); sysbus_init_mmio(sbd, &s->iomem); + qdev_init_gpio_out_named(DEVICE(obj), &s->remap, "remap", 1); } static void mps2_scc_realize(DeviceState *dev, Error **errp) @@ -353,6 +358,8 @@ static Property mps2_scc_properties[] = { DEFINE_PROP_UINT32("scc-cfg4", MPS2SCC, cfg4, 0), DEFINE_PROP_UINT32("scc-aid", MPS2SCC, aid, 0), DEFINE_PROP_UINT32("scc-id", MPS2SCC, id, 0), + /* Reset value for CFG0 register */ + DEFINE_PROP_UINT32("scc-cfg0", MPS2SCC, cfg0_reset, 0), /* * These are the initial settings for the source clocks on the board. * In hardware they can be configured via a config file read by the diff --git a/include/hw/misc/mps2-scc.h b/include/hw/misc/mps2-scc.h index ea261ea30d..3b2d13ac9c 100644 --- a/include/hw/misc/mps2-scc.h +++ b/include/hw/misc/mps2-scc.h @@ -18,8 +18,14 @@ * + QOM property "scc-cfg4": value of the read-only CFG4 register * + QOM property "scc-aid": value of the read-only SCC_AID register * + QOM property "scc-id": value of the read-only SCC_ID register + * + QOM property "scc-cfg0": reset value of the CFG0 register * + QOM property array "oscclk": reset values of the OSCCLK registers * (which are accessed via the SYS_CFG channel provided by this device) + * + named GPIO output "remap": this tracks the value of CFG0 register + * bit 0. Boards where this bit controls memory remapping should + * connect this GPIO line to a function performing that mapping. + * Boards where bit 0 has no special function should leave the GPIO + * output disconnected. */ #ifndef MPS2_SCC_H #define MPS2_SCC_H @@ -55,6 +61,9 @@ struct MPS2SCC { uint32_t num_oscclk; uint32_t *oscclk; uint32_t *oscclk_reset; + uint32_t cfg0_reset; + + qemu_irq remap; }; #endif