It is possible to specify a regulator that should be turned on when dw_mmc is probed. This regulator is optional, though a warning will be printed if it's missing. The fact that the regulator is optional means that (at the moment) it's not possible to use a regulator that probes _after_ dw_mmc. Fix this limitation by adding the ability to make vmmc required. If a vmmc-supply is specified in the device tree we'll assume that vmmc is required. Signed-off-by: Doug Anderson <dianders@xxxxxxxxxxxx> --- .../devicetree/bindings/mmc/synopsis-dw-mshc.txt | 3 +++ drivers/mmc/host/dw_mmc.c | 22 ++++++++++++++++++++-- include/linux/mmc/dw_mmc.h | 3 +++ 3 files changed, 26 insertions(+), 2 deletions(-) diff --git a/Documentation/devicetree/bindings/mmc/synopsis-dw-mshc.txt b/Documentation/devicetree/bindings/mmc/synopsis-dw-mshc.txt index 726fd21..b09d2d0 100644 --- a/Documentation/devicetree/bindings/mmc/synopsis-dw-mshc.txt +++ b/Documentation/devicetree/bindings/mmc/synopsis-dw-mshc.txt @@ -55,6 +55,9 @@ Optional properties: * broken-cd: as documented in mmc core bindings. +* vmmc-supply: The phandle to the regulator to use for vmmc. If this is + specified we'll defer probe until we can find this regulator. + Aliases: - All the MSHC controller nodes should be represented in the aliases node using diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c index bc3a1bc..d3a0f8a 100644 --- a/drivers/mmc/host/dw_mmc.c +++ b/drivers/mmc/host/dw_mmc.c @@ -1987,8 +1987,17 @@ static int dw_mci_init_slot(struct dw_mci *host, unsigned int id) host->vmmc = devm_regulator_get(mmc_dev(mmc), "vmmc"); if (IS_ERR(host->vmmc)) { - pr_info("%s: no vmmc regulator found\n", mmc_hostname(mmc)); + ret = PTR_ERR(host->vmmc); host->vmmc = NULL; + + if (host->pdata->vmmc_required) { + if (ret != -EPROBE_DEFER) + pr_err("%s: vmmc required: %d\n", + mmc_hostname(mmc), ret); + goto err_setup_bus; + } + pr_info("%s: no vmmc regulator found %d\n", mmc_hostname(mmc), + ret); } else { ret = regulator_enable(host->vmmc); if (ret) { @@ -2026,7 +2035,7 @@ static int dw_mci_init_slot(struct dw_mci *host, unsigned int id) err_setup_bus: mmc_free_host(mmc); - return -EINVAL; + return ret; } static void dw_mci_cleanup_slot(struct dw_mci_slot *slot, unsigned int id) @@ -2162,6 +2171,13 @@ static struct dw_mci_board *dw_mci_parse_dt(struct dw_mci *host) if (of_find_property(np, "enable-sdio-wakeup", NULL)) pdata->pm_caps |= MMC_PM_WAKE_SDIO_IRQ; + /* + * If vmmc is directly specified in the device tree then we'll assume + * it's required and honor EPROBE_DEFER so it can show up late. + */ + if (of_find_property(np, "vmmc-supply", NULL)) + pdata->vmmc_required = 1; + return pdata; } @@ -2352,6 +2368,8 @@ int dw_mci_probe(struct dw_mci *host) /* We need at least one slot to succeed */ for (i = 0; i < host->num_slots; i++) { ret = dw_mci_init_slot(host, i); + if (ret == -EPROBE_DEFER) + goto err_workqueue; if (ret) dev_dbg(host->dev, "slot %d init failed\n", i); else diff --git a/include/linux/mmc/dw_mmc.h b/include/linux/mmc/dw_mmc.h index 198f0fa..e84d288 100644 --- a/include/linux/mmc/dw_mmc.h +++ b/include/linux/mmc/dw_mmc.h @@ -244,6 +244,9 @@ struct dw_mci_board { /* delay in mS before detecting cards after interrupt */ u32 detect_delay_ms; + /* If true then we won't probe until vmmc is available */ + bool vmmc_required; + int (*init)(u32 slot_id, irq_handler_t , void *); int (*get_ro)(u32 slot_id); int (*get_cd)(u32 slot_id); -- 1.8.3 -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html