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authorPhilip Rakity <prakity@marvell.com>2012-05-27 18:36:44 -0700
committerChris Ball <cjb@laptop.org>2012-07-21 00:02:22 -0400
commitbad37e1ac6b1a73ed30702b24a45c27c4f53aada (patch)
treef296dfee6adbb7c7b781285cd447b3aed53fa0ed /drivers/mmc/host
parente480606ad43bb72fd82a9bd99cdcf21829a6e9c0 (diff)
downloadlinux-linaro-stable-bad37e1ac6b1a73ed30702b24a45c27c4f53aada.tar.gz
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>
Diffstat (limited to 'drivers/mmc/host')
-rw-r--r--drivers/mmc/host/sdhci.c28
-rw-r--r--drivers/mmc/host/sdhci.h1
2 files changed, 23 insertions, 6 deletions
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index f4b8b4db3a9a..a0853d03b330 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -2837,6 +2837,13 @@ int sdhci_add_host(struct sdhci_host *host)
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 @@ int sdhci_add_host(struct sdhci_host *host)
* 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 @@ int sdhci_add_host(struct sdhci_host *host)
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 f761f23d2a28..97653ea8942b 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