HSI: omap_ssi_port: replace wkin_cken with atomic bitmap operations

This simplifies the code and avoids holding a spin_lock when
runtime pm calls are made. Once the irq_safe flag is removed
for omap_ssi's runtime pm, pm_runtime_get/put_sync can sleep,
which is a no-go while holding a spin_lock.

Signed-off-by: Sebastian Reichel <sre@kernel.org>
Tested-by: Pavel Machek <pavel@ucw.cz>

2 files changed, 7 insertions, 15 deletions

diff --git a/drivers/hsi/controllers/omap_ssi.h b/drivers/hsi/controllers/omap_ssi.h
index 88a523902a8f..6cdaad8805f7 100644
--- a/drivers/hsi/controllers/omap_ssi.h
+++ b/drivers/hsi/controllers/omap_ssi.h
@@ -35,6 +35,8 @@
 #define SSI_MAX_GDD_LCH         8
 #define SSI_BYTES_TO_FRAMES(x) ((((x) - 1) >> 2) + 1)
 
+#define SSI_WAKE_EN 0
+
 /**
  * struct omap_ssm_ctx - OMAP synchronous serial module (TX/RX) context
  * @mode: Bit transmission mode
@@ -75,7 +77,7 @@ struct omap_ssm_ctx {
  * @wake_irq: IRQ number for incoming wake line (-1 if none)
  * @wake_gpio: GPIO number for incoming wake line (-1 if none)
  * @pio_tasklet: Bottom half for PIO transfers and events
- * @wkin_cken: Keep track of clock references due to the incoming wake line
+ * @flags: flags to keep track of states
  * @wk_refcount: Reference count for output wake line
  * @sys_mpu_enable: Context for the interrupt enable register for irq 0
  * @sst: Context for the synchronous serial transmitter
@@ -99,7 +101,7 @@ struct omap_ssi_port {
         struct gpio_desc        *wake_gpio;
         struct tasklet_struct   pio_tasklet;
         bool                    wktest:1; /* FIXME: HACK to be removed */
-        bool                    wkin_cken:1; /* Workaround */
+        unsigned long           flags;
         unsigned int            wk_refcount;
         /* OMAP SSI port context */
         u32                     sys_mpu_enable; /* We use only one irq */
diff --git a/drivers/hsi/controllers/omap_ssi_port.c b/drivers/hsi/controllers/omap_ssi_port.c
index 9001b06312c3..0d3452393670 100644
--- a/drivers/hsi/controllers/omap_ssi_port.c
+++ b/drivers/hsi/controllers/omap_ssi_port.c
@@ -751,10 +751,8 @@ static int ssi_release(struct hsi_client *cl)
                  * Drop the clock reference for the incoming wake line
                  * if it is still kept high by the other side.
                  */
-                if (omap_port->wkin_cken) {
+                if (test_and_clear_bit(SSI_WAKE_EN, &omap_port->flags))
                         pm_runtime_put_sync(omap_port->pdev);
-                        omap_port->wkin_cken = 0;
-                }
                 pm_runtime_get_sync(omap_port->pdev);
                 /* Stop any SSI TX/RX without a client */
                 ssi_set_port_mode(omap_port, SSI_MODE_SLEEP);
@@ -981,12 +979,8 @@ static irqreturn_t ssi_wake_thread(int irq __maybe_unused, void *ssi_port)
                  * This workaround will avoid breaking the clock reference
                  * count when such a situation ocurrs.
                  */
-                spin_lock(&omap_port->lock);
-                if (!omap_port->wkin_cken) {
-                        omap_port->wkin_cken = 1;
+                if (!test_and_set_bit(SSI_WAKE_EN, &omap_port->flags))
                         pm_runtime_get_sync(omap_port->pdev);
-                }
-                spin_unlock(&omap_port->lock);
                 dev_dbg(&ssi->device, "Wake in high\n");
                 if (omap_port->wktest) { /* FIXME: HACK ! To be removed */
                         writel(SSI_WAKE(0),
@@ -1000,12 +994,8 @@ static irqreturn_t ssi_wake_thread(int irq __maybe_unused, void *ssi_port)
                                 omap_ssi->sys + SSI_CLEAR_WAKE_REG(port->num));
                 }
                 hsi_event(port, HSI_EVENT_STOP_RX);
-                spin_lock(&omap_port->lock);
-                if (omap_port->wkin_cken) {
+                if (test_and_clear_bit(SSI_WAKE_EN, &omap_port->flags))
                         pm_runtime_put_sync(omap_port->pdev);
-                        omap_port->wkin_cken = 0;
-                }
-                spin_unlock(&omap_port->lock);
         }
 
         return IRQ_HANDLED;