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sdhci_xenon: improve the VCCQ voltage switch sequence

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Improve the VCCQ voltage switch, so that to properly
handle the SDHCI_HOST_CONTROL2 register signaling
flags and along with manipulating the regulator.

Reviewed by: manu
Obtained from: Semihalf
Sponsored by: Marvell
Differential Revision: https://reviews.freebsd.org/D30564
MFC after: 2 weeks

(cherry picked from commit c80e2ca57e)
This commit is contained in:
Marcin Wojtas 2021-05-27 20:39:12 +02:00
parent 68be9ab5bd
commit 7518736826
1 changed files with 68 additions and 16 deletions
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76
sys/dev/sdhci/sdhci_xenon.c
View File

@ -388,26 +388,32 @@ sdhci_xenon_switch_vccq(device_t brdev, device_t reqdev)
{
struct sdhci_xenon_softc *sc;
struct sdhci_slot *slot;
uint16_t hostctrl2;
int uvolt, err;
slot = device_get_ivars(reqdev);
if (slot->version < SDHCI_SPEC_300)
return (0);
sc = device_get_softc(brdev);
if (sc->mmc_helper.vqmmc_supply == NULL)
return EOPNOTSUPP;
slot = device_get_ivars(reqdev);
switch (slot->host.ios.vccq) {
case vccq_180:
uvolt = 1800000;
break;
case vccq_330:
uvolt = 3300000;
break;
default:
return EINVAL;
}
err = 0;
err = regulator_set_voltage(sc->mmc_helper.vqmmc_supply, uvolt, uvolt);
hostctrl2 = bus_read_2(sc->mem_res, SDHCI_HOST_CONTROL2);
switch (slot->host.ios.vccq) {
case vccq_330:
if (!(hostctrl2 & SDHCI_CTRL2_S18_ENABLE))
return (0);
hostctrl2 &= ~SDHCI_CTRL2_S18_ENABLE;
bus_write_2(sc->mem_res, SDHCI_HOST_CONTROL2, hostctrl2);
uvolt = 3300000;
err = regulator_set_voltage(sc->mmc_helper.vqmmc_supply,
uvolt, uvolt);
if (err != 0) {
device_printf(sc->dev,
"Cannot set vqmmc to %d<->%d\n",
@ -416,7 +422,53 @@ sdhci_xenon_switch_vccq(device_t brdev, device_t reqdev)
return (err);
}
/*
* According to the 'SD Host Controller Simplified
* Specification 4.20 the host driver should take more
* than 5ms for stable time of host voltage regulator
* from changing 1.8V Signaling Enable.
*/
DELAY(5000);
hostctrl2 = bus_read_2(sc->mem_res, SDHCI_HOST_CONTROL2);
if (!(hostctrl2 & SDHCI_CTRL2_S18_ENABLE))
return (0);
return EAGAIN;
case vccq_180:
if (!(slot->host.caps & MMC_CAP_SIGNALING_180)) {
return EINVAL;
}
if (hostctrl2 & SDHCI_CTRL2_S18_ENABLE)
return (0);
hostctrl2 |= SDHCI_CTRL2_S18_ENABLE;
bus_write_2(sc->mem_res, SDHCI_HOST_CONTROL2, hostctrl2);
uvolt = 1800000;
err = regulator_set_voltage(sc->mmc_helper.vqmmc_supply,
uvolt, uvolt);
if (err != 0) {
device_printf(sc->dev,
"Cannot set vqmmc to %d<->%d\n",
uvolt,
uvolt);
return (err);
}
/*
* According to the 'SD Host Controller Simplified
* Specification 4.20 the host driver should take more
* than 5ms for stable time of host voltage regulator
* from changing 1.8V Signaling Enable.
*/
DELAY(5000);
hostctrl2 = bus_read_2(sc->mem_res, SDHCI_HOST_CONTROL2);
if (hostctrl2 & SDHCI_CTRL2_S18_ENABLE)
return (0);
return EAGAIN;
default:
device_printf(brdev,
"Attempt to set unsupported signaling voltage\n");
return EINVAL;
}
}
static int