[RFC PATCH] mmc: host: add a new cap to force set power control

From: Beata Baranowska
Date: Tue Jun 28 2016 - 05:48:37 EST


From: Chuanxiao Dong <chuanxiao.dong@xxxxxxxxx>

Even with a regulator, some host controller still needs to
set the power control register to make sure the inter logical
is working

Signed-off-by: Chuanxiao Dong <chuanxiao.dong@xxxxxxxxx>
---
drivers/mmc/host/sdhci-acpi.c | 5 ++++-
drivers/mmc/host/sdhci.c | 10 ++++++----
include/linux/mmc/host.h | 6 ++++++
3 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/drivers/mmc/host/sdhci-acpi.c b/drivers/mmc/host/sdhci-acpi.c
index 458ffb7637e5..23f436ec5803 100644
--- a/drivers/mmc/host/sdhci-acpi.c
+++ b/drivers/mmc/host/sdhci-acpi.c
@@ -275,7 +275,8 @@ static const struct sdhci_acpi_slot sdhci_acpi_slot_int_emmc = {
.caps = MMC_CAP_8_BIT_DATA | MMC_CAP_NONREMOVABLE |
MMC_CAP_HW_RESET | MMC_CAP_1_8V_DDR |
MMC_CAP_WAIT_WHILE_BUSY,
- .caps2 = MMC_CAP2_HC_ERASE_SZ,
+ .caps2 = MMC_CAP2_HC_ERASE_SZ |
+ MMC_CAP2_FORCE_SET_PWR_CTRL,
.flags = SDHCI_ACPI_RUNTIME_PM,
.quirks = SDHCI_QUIRK_NO_ENDATTR_IN_NOPDESC,
.quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN |
@@ -290,6 +291,7 @@ static const struct sdhci_acpi_slot sdhci_acpi_slot_int_sdio = {
.quirks2 = SDHCI_QUIRK2_HOST_OFF_CARD_ON,
.caps = MMC_CAP_NONREMOVABLE | MMC_CAP_POWER_OFF_CARD |
MMC_CAP_WAIT_WHILE_BUSY,
+ .caps2 = MMC_CAP2_FORCE_SET_PWR_CTRL,
.flags = SDHCI_ACPI_RUNTIME_PM,
.pm_caps = MMC_PM_KEEP_POWER,
.probe_slot = sdhci_acpi_sdio_probe_slot,
@@ -302,6 +304,7 @@ static const struct sdhci_acpi_slot sdhci_acpi_slot_int_sd = {
.quirks2 = SDHCI_QUIRK2_CARD_ON_NEEDS_BUS_ON |
SDHCI_QUIRK2_STOP_WITH_TC,
.caps = MMC_CAP_WAIT_WHILE_BUSY,
+ .caps2 = MMC_CAP2_FORCE_SET_PWR_CTRL,
.probe_slot = sdhci_acpi_sd_probe_slot,
};

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 0e3d7c056cb1..9b50648d320f 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1268,10 +1268,12 @@ static void sdhci_set_power_reg(struct sdhci_host *host, unsigned char mode,
mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, vdd);
spin_lock_irq(&host->lock);

- if (mode != MMC_POWER_OFF)
- sdhci_writeb(host, SDHCI_POWER_ON, SDHCI_POWER_CONTROL);
- else
- sdhci_writeb(host, 0, SDHCI_POWER_CONTROL);
+ if (!(mmc->caps2 & MMC_CAP2_FORCE_SET_PWR_CTRL)) {
+ if (mode != MMC_POWER_OFF)
+ sdhci_writeb(host, SDHCI_POWER_ON, SDHCI_POWER_CONTROL);
+ else
+ sdhci_writeb(host, 0, SDHCI_POWER_CONTROL);
+ }
}

void sdhci_set_power(struct sdhci_host *host, unsigned char mode,
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 45cde8cd39f2..0eee78d17722 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -303,6 +303,12 @@ struct mmc_host {
#define MMC_CAP2_NO_WRITE_PROTECT (1 << 18) /* No physical write protect pin, assume that card is always read-write */
#define MMC_CAP2_NO_SDIO (1 << 19) /* Do not send SDIO commands during initialization */

+/*
+ * For the host which needs to config its power control
+ * register even it has regulators
+ */
+#define MMC_CAP2_FORCE_SET_PWR_CTRL (1 << 20)
+
mmc_pm_flag_t pm_caps; /* supported pm features */

/* host specific block data */
--
1.9.1