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mmc: sh_mmcif: Restructure ->set_ios()

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Both from a runtime PM and clock management point of view, the ->set_ios()
code is unnecessary complex.

A suboptimal path is also executed when the mmc core requests a clock rate
of zero. As that happens during the card initialization phase, trying to
save power by decreasing the runtime PM usage count and gating the clock
via clk_disable_unprepare() is just superfluous.

Moreover, from a runtime PM point of view the core will anyway keep the
device active during the entire card initialization phase.

Restructure the code to rely on the ios->power_mode to understand when the
runtime PM usage count needs to be increased. Let's also deal with clock
rate changes by simply applying the rate.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This commit is contained in:
Ulf Hansson 2016-02-11 13:59:54 +01:00
parent 88ac2a2c30
commit 4caf653a55
1 changed files with 17 additions and 30 deletions
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47
drivers/mmc/host/sh_mmcif.c
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@ -248,7 +248,6 @@ struct sh_mmcif_host {
int sg_idx;
int sg_blkidx;
bool power;
bool card_present;
bool ccs_enable; /* Command Completion Signal support */
bool clk_ctrl2_enable;
struct mutex thread_lock;
@ -1091,42 +1090,30 @@ static void sh_mmcif_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
host->state = STATE_IOS;
spin_unlock_irqrestore(&host->lock, flags);
if (ios->power_mode == MMC_POWER_UP) {
if (!host->card_present) {
/* See if we also get DMA */
sh_mmcif_request_dma(host);
host->card_present = true;
}
switch (ios->power_mode) {
case MMC_POWER_UP:
sh_mmcif_set_power(host, ios);
} else if (ios->power_mode == MMC_POWER_OFF || !ios->clock) {
/* clock stop */
sh_mmcif_clock_control(host, 0);
if (ios->power_mode == MMC_POWER_OFF) {
if (host->card_present) {
sh_mmcif_release_dma(host);
host->card_present = false;
}
}
if (host->power) {
pm_runtime_put_sync(dev);
clk_disable_unprepare(host->clk);
host->power = false;
if (ios->power_mode == MMC_POWER_OFF)
sh_mmcif_set_power(host, ios);
}
host->state = STATE_IDLE;
return;
}
if (ios->clock) {
if (!host->power) {
clk_prepare_enable(host->clk);
pm_runtime_get_sync(dev);
host->power = true;
sh_mmcif_sync_reset(host);
sh_mmcif_request_dma(host);
host->power = true;
}
break;
case MMC_POWER_OFF:
sh_mmcif_set_power(host, ios);
if (host->power) {
sh_mmcif_clock_control(host, 0);
sh_mmcif_release_dma(host);
pm_runtime_put(dev);
clk_disable_unprepare(host->clk);
host->power = false;
}
break;
case MMC_POWER_ON:
sh_mmcif_clock_control(host, ios->clock);
break;
}
host->timing = ios->timing;