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mmc: sdhci: if MAX_CURRENT is 0, try getting current from regulator

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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>
This commit is contained in:
Philip Rakity 2012-05-27 18:36:44 -07:00 committed by Chris Ball
parent e480606ad4
commit bad37e1ac6
2 changed files with 23 additions and 6 deletions
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28
drivers/mmc/host/sdhci.c
View File

@ -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

1
drivers/mmc/host/sdhci.h
View File

@ -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