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authorPhilippe Mathieu-Daudé <f4bug@amsat.org>2018-07-09 14:51:34 +0100
committerPeter Maydell <peter.maydell@linaro.org>2018-07-09 14:51:34 +0100
commit7abf56eed13a2338b8d3eda60e0d3c4e490a663f (patch)
treee3e31b9bc77eb665ed6854b6a01b42b97233f853
parent973558a3f869e591d2406dd8226ec0c4e32a3c3e (diff)
downloadqemu-arm-7abf56eed13a2338b8d3eda60e0d3c4e490a663f.tar.gz
hw/sd/omap_mmc: Split 'pseudo-reset' from 'power-on-reset'
DeviceClass::reset models a "cold power-on" reset which can also be used to powercycle a device; but there is no "hot reset" (a.k.a. soft-reset) method available. The OMAP MMC Power-Up Control bit is not designed to powercycle a card, but to disable it without powering it off (pseudo-reset): Multimedia Card (MMC/SD/SDIO) Interface [SPRU765A] MMC_CON[11] Power-Up Control (POW) This bit must be set to 1 before any valid transaction to either MMC/SD or SPI memory cards. When 1, the card is considered powered-up and the controller core is enabled. When 0, the card is considered powered-down (system dependent), and the controller core logic is in pseudo-reset state. This is, the MMC_STAT flags and the FIFO pointers are reset, any access to MMC_DATA[DATA] has no effect, a write into the MMC.CMD register is ignored, and a setting of MMC_SPI[STR] to 1 is ignored. By splitting the 'pseudo-reset' code out of the 'power-on' reset function, this patch fixes a latent bug in omap_mmc_write(MMC_CON)i recently exposed by ecd219f7abb. Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Message-id: 20180706162155.8432-2-f4bug@amsat.org Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
-rw-r--r--hw/sd/omap_mmc.c14
1 files changed, 11 insertions, 3 deletions
diff --git a/hw/sd/omap_mmc.c b/hw/sd/omap_mmc.c
index 671264b650..d0c98ca021 100644
--- a/hw/sd/omap_mmc.c
+++ b/hw/sd/omap_mmc.c
@@ -1,6 +1,8 @@
/*
* OMAP on-chip MMC/SD host emulation.
*
+ * Datasheet: TI Multimedia Card (MMC/SD/SDIO) Interface (SPRU765A)
+ *
* Copyright (C) 2006-2007 Andrzej Zaborowski <balrog@zabor.org>
*
* This program is free software; you can redistribute it and/or
@@ -278,6 +280,12 @@ static void omap_mmc_update(void *opaque)
omap_mmc_interrupts_update(s);
}
+static void omap_mmc_pseudo_reset(struct omap_mmc_s *host)
+{
+ host->status = 0;
+ host->fifo_len = 0;
+}
+
void omap_mmc_reset(struct omap_mmc_s *host)
{
host->last_cmd = 0;
@@ -286,11 +294,9 @@ void omap_mmc_reset(struct omap_mmc_s *host)
host->dw = 0;
host->mode = 0;
host->enable = 0;
- host->status = 0;
host->mask = 0;
host->cto = 0;
host->dto = 0;
- host->fifo_len = 0;
host->blen = 0;
host->blen_counter = 0;
host->nblk = 0;
@@ -305,6 +311,8 @@ void omap_mmc_reset(struct omap_mmc_s *host)
qemu_set_irq(host->coverswitch, host->cdet_state);
host->clkdiv = 0;
+ omap_mmc_pseudo_reset(host);
+
/* Since we're still using the legacy SD API the card is not plugged
* into any bus, and we must reset it manually. When omap_mmc is
* QOMified this must move into the QOM reset function.
@@ -459,7 +467,7 @@ static void omap_mmc_write(void *opaque, hwaddr offset,
if (s->dw != 0 && s->lines < 4)
printf("4-bit SD bus enabled\n");
if (!s->enable)
- omap_mmc_reset(s);
+ omap_mmc_pseudo_reset(s);
break;
case 0x10: /* MMC_STAT */