From ae628903ab6cc9a04fdf8d4ff3f0c5b2ffa6f939 Mon Sep 17 00:00:00 2001
From: Pierre Ossman <pierre@ossman.eu>
Date: Sun, 3 May 2009 20:45:03 +0200
Subject: [PATCH] sdhci: avoid changing voltage needlessly
Because of granularity issues, sometimes we told the hardware to change
to the voltage we were already at. Rework the logic so this doesn't
happen.
Signed-off-by: Pierre Ossman <pierre@ossman.eu>
---
drivers/mmc/host/sdhci.c | 53 +++++++++++++++++++++-------------------
drivers/mmc/host/sdhci.h | 2 +-
2 files changed, 29 insertions(+), 26 deletions(-)
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 9234be2226e7..1432a35690dd 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1005,12 +1005,34 @@ static void sdhci_set_power(struct sdhci_host *host, unsigned short power)
{
u8 pwr;
- if (host->power == power)
+ if (power == (unsigned short)-1)
+ pwr = 0;
+ else {
+ switch (1 << power) {
+ case MMC_VDD_165_195:
+ pwr = SDHCI_POWER_180;
+ break;
+ case MMC_VDD_29_30:
+ case MMC_VDD_30_31:
+ pwr = SDHCI_POWER_300;
+ break;
+ case MMC_VDD_32_33:
+ case MMC_VDD_33_34:
+ pwr = SDHCI_POWER_330;
+ break;
+ default:
+ BUG();
+ }
+ }
+
+ if (host->pwr == pwr)
return;
- if (power == (unsigned short)-1) {
+ host->pwr = pwr;
+
+ if (pwr == 0) {
sdhci_writeb(host, 0, SDHCI_POWER_CONTROL);
- goto out;
+ return;
}
/*
@@ -1020,35 +1042,16 @@ static void sdhci_set_power(struct sdhci_host *host, unsigned short power)
if (!(host->quirks & SDHCI_QUIRK_SINGLE_POWER_WRITE))
sdhci_writeb(host, 0, SDHCI_POWER_CONTROL);
- pwr = SDHCI_POWER_ON;
-
- switch (1 << power) {
- case MMC_VDD_165_195:
- pwr |= SDHCI_POWER_180;
- break;
- case MMC_VDD_29_30:
- case MMC_VDD_30_31:
- pwr |= SDHCI_POWER_300;
- break;
- case MMC_VDD_32_33:
- case MMC_VDD_33_34:
- pwr |= SDHCI_POWER_330;
- break;
- default:
- BUG();
- }
-
/*
* At least the Marvell CaFe chip gets confused if we set the voltage
* and set turn on power at the same time, so set the voltage first.
*/
if ((host->quirks & SDHCI_QUIRK_NO_SIMULT_VDD_AND_POWER))
- sdhci_writeb(host, pwr & ~SDHCI_POWER_ON, SDHCI_POWER_CONTROL);
+ sdhci_writeb(host, pwr, SDHCI_POWER_CONTROL);
- sdhci_writeb(host, pwr, SDHCI_POWER_CONTROL);
+ pwr |= SDHCI_POWER_ON;
-out:
- host->power = power;
+ sdhci_writeb(host, pwr, SDHCI_POWER_CONTROL);
}
/*****************************************************************************\
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index 65c6f996bbd3..2de08349c3ca 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -255,7 +255,7 @@ struct sdhci_host {
unsigned int timeout_clk; /* Timeout freq (KHz) */
unsigned int clock; /* Current clock (MHz) */
- unsigned short power; /* Current voltage */
+ u8 pwr; /* Current voltage */
struct mmc_request *mrq; /* Current request */
struct mmc_command *cmd; /* Current command */
--
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