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>

diff --git a/Documentation/devicetree/bindings/mmc/synopsis-dw-mshc.txt b/Documentation/devicetree/bindings/mmc/synopsis-dw-mshc.txt
index 726fd21..d5cc94e 100644 (file)
--- 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.
 
 
 * 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
 Aliases:
 
 - All the MSHC controller nodes should be represented in the aliases node using


@@ -79,6 +82,7 @@ board specific portions as listed below.
                broken-cd;
                fifo-depth = <0x80>;
                card-detect-delay = <200>;
                broken-cd;
                fifo-depth = <0x80>;
                card-detect-delay = <200>;

+               vmmc-supply = <&buck8>;

 
                slot@0 {
                        reg = <0>;
 
                slot@0 {
                        reg = <0>;

diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index 7dca5e9..957f5d7 100644 (file)
--- 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 */
        }
 
 #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
        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;
        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;
        }
 
        host->quirks = host->pdata->quirks;


@@ -2386,6 +2391,7 @@ err_dmaunmap:
        if (host->use_dma && host->dma_ops->exit)
                host->dma_ops->exit(host);
 
        if (host->use_dma && host->dma_ops->exit)
                host->dma_ops->exit(host);
 

+err_regulator:

        if (host->vmmc)
                regulator_disable(host->vmmc);
 
        if (host->vmmc)
                regulator_disable(host->vmmc);