mmc: dw_mmc: Handle late vmmc regulators with EPROBE_DEFER

It is possible to specify a regulator that should be turned on when
dw_mmc is probed.  At the moment dw_mmc will fail to use the regulator
properly if the regulator probes after dw_mmc.  Fix this problem by
honoring EPROBE_DEFER.

At the same time move the regulator code out of the slot init code.
We only specify one regulator for the whole device and other parts of
the code (like suspend/resume) assume that the regulator has only been
enabled once.

Signed-off-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Chris Ball <cjb@laptop.org>

1 files changed, 20 insertions, 14 deletions

diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index 7dca5e92dcb4..957f5d7ea426 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -1991,19 +1991,6 @@ static int dw_mci_init_slot(struct dw_mci *host, unsigned int id)
 #endif /* CONFIG_MMC_DW_IDMAC */
         }
 
-        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));
-                host->vmmc = NULL;
-        } else {
-                ret = regulator_enable(host->vmmc);
-                if (ret) {
-                        dev_err(host->dev,
-                                "failed to enable regulator: %d\n", ret);
-                        goto err_setup_bus;
-                }
-        }
-
         if (dw_mci_get_cd(mmc))
                 set_bit(DW_MMC_CARD_PRESENT, &slot->flags);
         else
@@ -2235,11 +2222,29 @@ int dw_mci_probe(struct dw_mci *host)
                 }
         }
 
+        host->vmmc = devm_regulator_get(host->dev, "vmmc");
+        if (IS_ERR(host->vmmc)) {
+                ret = PTR_ERR(host->vmmc);
+                if (ret == -EPROBE_DEFER)
+                        goto err_clk_ciu;
+
+                dev_info(host->dev, "no vmmc regulator found: %d\n", ret);
+                host->vmmc = NULL;
+        } else {
+                ret = regulator_enable(host->vmmc);
+                if (ret) {
+                        if (ret != -EPROBE_DEFER)
+                                dev_err(host->dev,
+                                        "regulator_enable fail: %d\n", ret);
+                        goto err_clk_ciu;
+                }
+        }
+
         if (!host->bus_hz) {
                 dev_err(host->dev,
                         "Platform data must supply bus speed\n");
                 ret = -ENODEV;
-                goto err_clk_ciu;
+                goto err_regulator;
         }
 
         host->quirks = host->pdata->quirks;
@@ -2386,6 +2391,7 @@ err_dmaunmap:
         if (host->use_dma && host->dma_ops->exit)
                 host->dma_ops->exit(host);
 
+err_regulator:
         if (host->vmmc)
                 regulator_disable(host->vmmc);