mmc: sh_mmcif: Restructure ->set_ios()

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>

diff --git a/drivers/mmc/host/sh_mmcif.c b/drivers/mmc/host/sh_mmcif.c
index ee59786..cdefb01 100644 (file)
--- a/drivers/mmc/host/sh_mmcif.c
+++ b/drivers/mmc/host/sh_mmcif.c
@@ -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 */
+       switch (ios->power_mode) {
+       case MMC_POWER_UP:
+               sh_mmcif_set_power(host, ios);
+               if (!host->power) {
+                       clk_prepare_enable(host->clk);
+                       pm_runtime_get_sync(dev);
+                       sh_mmcif_sync_reset(host);
                        sh_mmcif_request_dma(host);
-                       host->card_present = true;
+                       host->power = true;
                }
+               break;
+       case MMC_POWER_OFF:
                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);
+                       sh_mmcif_clock_control(host, 0);
+                       sh_mmcif_release_dma(host);
+                       pm_runtime_put(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);
                }
+               break;
+       case MMC_POWER_ON:
                sh_mmcif_clock_control(host, ios->clock);
+               break;
        }
 
        host->timing = ios->timing;