diff options
| author | Philippe Mathieu-Daudé <f4bug@amsat.org> | 2018-07-09 14:51:34 +0100 |
|---|---|---|
| committer | Peter Maydell <peter.maydell@linaro.org> | 2018-07-09 14:51:34 +0100 |
| commit | 7abf56eed13a2338b8d3eda60e0d3c4e490a663f (patch) | |
| tree | e3e31b9bc77eb665ed6854b6a01b42b97233f853 | |
| parent | 973558a3f869e591d2406dd8226ec0c4e32a3c3e (diff) | |
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.c | 14 |
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 */ |