mmc: sdhci: if MAX_CURRENT is 0, try getting current from regulator
The sd host controller spec indicates the the MAX_CURRENT value may
be returned as 0. In this case other methods need to be used to
return the current. If 0 is returned and there is a regulator,
ask the regulator for how much current is available.
Signed-off-by: Philip Rakity <prakity@marvell.com>
Signed-off-by: Mark F. Brown <mark.brown314@gmail.com>
Reviewed-by: Aaron Lu <aaron.lu@amd.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index f4b8b4d..a0853d0 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -2837,6 +2837,13 @@
SDHCI_RETUNING_MODE_SHIFT;
ocr_avail = 0;
+
+ host->vmmc = 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;
+ }
+
/*
* According to SD Host Controller spec v3.00, if the Host System
* can afford more than 150mA, Host Driver should set XPC to 1. Also
@@ -2845,6 +2852,21 @@
* value.
*/
max_current_caps = sdhci_readl(host, SDHCI_MAX_CURRENT);
+ if (!max_current_caps && host->vmmc) {
+ u32 curr = regulator_get_current_limit(host->vmmc);
+ if (curr > 0) {
+
+ /* convert to SDHCI_MAX_CURRENT format */
+ curr = curr/1000; /* convert to mA */
+ curr = curr/SDHCI_MAX_CURRENT_MULTIPLIER;
+
+ curr = min_t(u32, curr, SDHCI_MAX_CURRENT_LIMIT);
+ max_current_caps =
+ (curr << SDHCI_MAX_CURRENT_330_SHIFT) |
+ (curr << SDHCI_MAX_CURRENT_300_SHIFT) |
+ (curr << SDHCI_MAX_CURRENT_180_SHIFT);
+ }
+ }
if (caps[0] & SDHCI_CAN_VDD_330) {
int max_current_330;
@@ -2995,12 +3017,6 @@
if (ret)
goto untasklet;
- host->vmmc = 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;
- }
-
sdhci_init(host, 0);
#ifdef CONFIG_MMC_DEBUG
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index f761f23..97653ea 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -205,6 +205,7 @@
#define SDHCI_CAPABILITIES_1 0x44
#define SDHCI_MAX_CURRENT 0x48
+#define SDHCI_MAX_CURRENT_LIMIT 0xFF
#define SDHCI_MAX_CURRENT_330_MASK 0x0000FF
#define SDHCI_MAX_CURRENT_330_SHIFT 0
#define SDHCI_MAX_CURRENT_300_MASK 0x00FF00