memstick: allow "set_param" method to return an error code

Some controllers (Jmicron, for instance) can report temporal failure
condition during power-on.  It is desirable to account for this using a
return value of "set_param" device method.  The return value can also be
handy to distinguish between supported and unsupported device parameters
in run time.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Alex Dubov <oakad@yahoo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 49 insertions, 18 deletions

diff --git a/drivers/memstick/host/jmb38x_ms.c b/drivers/memstick/host/jmb38x_ms.c
index 4e3bfbcdf155..9d82e67737db 100644
--- a/drivers/memstick/host/jmb38x_ms.c
+++ b/drivers/memstick/host/jmb38x_ms.c
@@ -609,36 +609,68 @@ static void jmb38x_ms_request(struct memstick_host *msh)
         spin_unlock_irqrestore(&host->lock, flags);
 }
 
-static void jmb38x_ms_reset(struct jmb38x_ms_host *host)
+static int jmb38x_ms_reset(struct jmb38x_ms_host *host)
 {
-        unsigned int host_ctl = readl(host->addr + HOST_CONTROL);
+        int cnt;
 
-        writel(HOST_CONTROL_RESET_REQ, host->addr + HOST_CONTROL);
+        writel(HOST_CONTROL_RESET_REQ | HOST_CONTROL_CLOCK_EN
+               | readl(host->addr + HOST_CONTROL),
+               host->addr + HOST_CONTROL);
+        mmiowb();
+
+        for (cnt = 0; cnt < 20; ++cnt) {
+                if (!(HOST_CONTROL_RESET_REQ
+                      & readl(host->addr + HOST_CONTROL)))
+                        goto reset_next;
 
-        while (HOST_CONTROL_RESET_REQ
-               & (host_ctl = readl(host->addr + HOST_CONTROL))) {
                 ndelay(20);
-                dev_dbg(&host->chip->pdev->dev, "reset %08x\n", host_ctl);
         }
+        dev_dbg(&host->chip->pdev->dev, "reset_req timeout\n");
+        return -EIO;
 
-        writel(HOST_CONTROL_RESET, host->addr + HOST_CONTROL);
+reset_next:
+        writel(HOST_CONTROL_RESET | HOST_CONTROL_CLOCK_EN
+               | readl(host->addr + HOST_CONTROL),
+               host->addr + HOST_CONTROL);
+        mmiowb();
+
+        for (cnt = 0; cnt < 20; ++cnt) {
+                if (!(HOST_CONTROL_RESET
+                      & readl(host->addr + HOST_CONTROL)))
+                        goto reset_ok;
+
+                ndelay(20);
+        }
+        dev_dbg(&host->chip->pdev->dev, "reset timeout\n");
+        return -EIO;
+
+reset_ok:
         mmiowb();
         writel(INT_STATUS_ALL, host->addr + INT_SIGNAL_ENABLE);
         writel(INT_STATUS_ALL, host->addr + INT_STATUS_ENABLE);
+        return 0;
 }
 
-static void jmb38x_ms_set_param(struct memstick_host *msh,
-                                enum memstick_param param,
-                                int value)
+static int jmb38x_ms_set_param(struct memstick_host *msh,
+                               enum memstick_param param,
+                               int value)
 {
         struct jmb38x_ms_host *host = memstick_priv(msh);
         unsigned int host_ctl = readl(host->addr + HOST_CONTROL);
         unsigned int clock_ctl = CLOCK_CONTROL_40MHZ, clock_delay = 0;
+        int rc = 0;
 
         switch (param) {
         case MEMSTICK_POWER:
                 if (value == MEMSTICK_POWER_ON) {
-                        jmb38x_ms_reset(host);
+                        rc = jmb38x_ms_reset(host);
+                        if (rc)
+                                return rc;
+
+                        host_ctl = 7;
+                        host_ctl |= HOST_CONTROL_POWER_EN
+                                 | HOST_CONTROL_CLOCK_EN;
+                        writel(host_ctl, host->addr + HOST_CONTROL);
 
                         writel(host->id ? PAD_PU_PD_ON_MS_SOCK1
                                         : PAD_PU_PD_ON_MS_SOCK0,
@@ -647,11 +679,7 @@ static void jmb38x_ms_set_param(struct memstick_host *msh,
                         writel(PAD_OUTPUT_ENABLE_MS,
                                host->addr + PAD_OUTPUT_ENABLE);
 
-                        host_ctl = 7;
-                        host_ctl |= HOST_CONTROL_POWER_EN
-                                 | HOST_CONTROL_CLOCK_EN;
-                        writel(host_ctl, host->addr + HOST_CONTROL);
-
+                        msleep(10);
                         dev_dbg(&host->chip->pdev->dev, "power on\n");
                 } else if (value == MEMSTICK_POWER_OFF) {
                         host_ctl &= ~(HOST_CONTROL_POWER_EN
@@ -660,7 +688,8 @@ static void jmb38x_ms_set_param(struct memstick_host *msh,
                         writel(0, host->addr + PAD_OUTPUT_ENABLE);
                         writel(PAD_PU_PD_OFF, host->addr + PAD_PU_PD);
                         dev_dbg(&host->chip->pdev->dev, "power off\n");
-                }
+                } else
+                        return -EINVAL;
                 break;
         case MEMSTICK_INTERFACE:
                 host_ctl &= ~(3 << HOST_CONTROL_IF_SHIFT);
@@ -686,12 +715,14 @@ static void jmb38x_ms_set_param(struct memstick_host *msh,
                         host_ctl &= ~HOST_CONTROL_REI;
                         clock_ctl = CLOCK_CONTROL_60MHZ;
                         clock_delay = 0;
-                }
+                } else
+                        return -EINVAL;
                 writel(host_ctl, host->addr + HOST_CONTROL);
                 writel(clock_ctl, host->addr + CLOCK_CONTROL);
                 writel(clock_delay, host->addr + CLOCK_DELAY);
                 break;
         };
+        return 0;
 }
 
 #ifdef CONFIG_PM