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authorLinus Walleij <linus.walleij@stericsson.com>2009-09-14 12:56:14 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2009-09-15 22:11:05 +0100
commita6a6464a0ecd20c5f1594a4fe5b24af6181b7366 (patch)
treef97039472b6a10b36d9e068e59f00c2bf290819e /drivers/mmc
parentbc581770cfdd8c17ea17d324dc05e2f9c599e7ca (diff)
ARM: 5697/1: MMCI Break out clock divider setup
This breaks out the clock divider set-up code from the mmci_set_ios() code and surrounds the two register writes with a host lock so we don't get collisions if (in future code) two code paths want to change the clock divider at the same time as can be the case if we get something like pre/post- clock frequency change notifications soonish. Signed-off-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'drivers/mmc')
-rw-r--r--drivers/mmc/host/mmci.c51
1 files changed, 34 insertions, 17 deletions
diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 8741d0f5146..031141a7c87 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -38,6 +38,33 @@
static unsigned int fmax = 515633;
+/*
+ * This must be called with host->lock held
+ */
+static void mmci_set_clkreg(struct mmci_host *host, unsigned int desired)
+{
+ u32 clk = 0;
+
+ if (desired) {
+ if (desired >= host->mclk) {
+ clk = MCI_CLK_BYPASS;
+ host->cclk = host->mclk;
+ } else {
+ clk = host->mclk / (2 * desired) - 1;
+ if (clk >= 256)
+ clk = 255;
+ host->cclk = host->mclk / (2 * (clk + 1));
+ }
+ if (host->hw_designer == 0x80)
+ clk |= MCI_FCEN; /* Bug fix in ST IP block */
+ clk |= MCI_CLK_ENABLE;
+ /* This hasn't proven to be worthwhile */
+ /* clk |= MCI_CLK_PWRSAVE; */
+ }
+
+ writel(clk, host->base + MMCICLOCK);
+}
+
static void
mmci_request_end(struct mmci_host *host, struct mmc_request *mrq)
{
@@ -419,22 +446,8 @@ static void mmci_request(struct mmc_host *mmc, struct mmc_request *mrq)
static void mmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
{
struct mmci_host *host = mmc_priv(mmc);
- u32 clk = 0, pwr = 0;
-
- if (ios->clock) {
- if (ios->clock >= host->mclk) {
- clk = MCI_CLK_BYPASS;
- host->cclk = host->mclk;
- } else {
- clk = host->mclk / (2 * ios->clock) - 1;
- if (clk >= 256)
- clk = 255;
- host->cclk = host->mclk / (2 * (clk + 1));
- }
- if (host->hw_designer == AMBA_VENDOR_ST)
- clk |= MCI_FCEN; /* Bug fix in ST IP block */
- clk |= MCI_CLK_ENABLE;
- }
+ u32 pwr = 0;
+ unsigned long flags;
if (host->plat->translate_vdd)
pwr |= host->plat->translate_vdd(mmc_dev(mmc), ios->vdd);
@@ -465,12 +478,16 @@ static void mmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
}
}
- writel(clk, host->base + MMCICLOCK);
+ spin_lock_irqsave(&host->lock, flags);
+
+ mmci_set_clkreg(host, ios->clock);
if (host->pwr != pwr) {
host->pwr = pwr;
writel(pwr, host->base + MMCIPOWER);
}
+
+ spin_unlock_irqrestore(&host->lock, flags);
}
static int mmci_get_ro(struct mmc_host *mmc)