Merge tag 'clk' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc

clock management changes for i.MX

Another simple series related to clock management, this time only for
imx.

* tag 'clk' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  ARM: mxs: select HAVE_CLK_PREPARE for clock
  clk: add config option HAVE_CLK_PREPARE into Kconfig
  ASoC: mxs-saif: convert to clk_prepare/clk_unprepare
  video: mxsfb: convert to clk_prepare/clk_unprepare
  serial: mxs-auart: convert to clk_prepare/clk_unprepare
  net: flexcan: convert to clk_prepare/clk_unprepare
  mtd: gpmi-lib: convert to clk_prepare/clk_unprepare
  mmc: mxs-mmc: convert to clk_prepare/clk_unprepare
  dma: mxs-dma: convert to clk_prepare/clk_unprepare
  net: fec: add clk_prepare/clk_unprepare
  ARM: mxs: convert platform code to clk_prepare/clk_unprepare
  clk: add helper functions clk_prepare_enable and clk_disable_unprepare

Fix up trivial conflicts in drivers/net/ethernet/freescale/fec.c due to
commit 0ebafefcaa7a ("net: fec: add clk_prepare/clk_unprepare") clashing
trivially with commit e163cc97f9ac ("net/fec: fix the .remove code").

7 files changed, 37 insertions, 23 deletions

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index b3d7b77d2d51..9d66dfc33a5a 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -447,6 +447,7 @@ config ARCH_MXS
         select ARCH_REQUIRE_GPIOLIB
         select CLKDEV_LOOKUP
         select CLKSRC_MMIO
+        select HAVE_CLK_PREPARE
         help
           Support for Freescale MXS-based family of processors
 
diff --git a/arch/arm/mach-mxs/clock-mx23.c b/arch/arm/mach-mxs/clock-mx23.c
index 0163b6d83773..e12e11231dc7 100644
--- a/arch/arm/mach-mxs/clock-mx23.c
+++ b/arch/arm/mach-mxs/clock-mx23.c
@@ -545,11 +545,11 @@ int __init mx23_clocks_init(void)
          */
         clk_set_parent(&ssp_clk, &ref_io_clk);
 
-        clk_enable(&cpu_clk);
-        clk_enable(&hbus_clk);
-        clk_enable(&xbus_clk);
-        clk_enable(&emi_clk);
-        clk_enable(&uart_clk);
+        clk_prepare_enable(&cpu_clk);
+        clk_prepare_enable(&hbus_clk);
+        clk_prepare_enable(&xbus_clk);
+        clk_prepare_enable(&emi_clk);
+        clk_prepare_enable(&uart_clk);
 
         clkdev_add_table(lookups, ARRAY_SIZE(lookups));
 
diff --git a/arch/arm/mach-mxs/clock-mx28.c b/arch/arm/mach-mxs/clock-mx28.c
index df0ad3ce234b..5d68e4152220 100644
--- a/arch/arm/mach-mxs/clock-mx28.c
+++ b/arch/arm/mach-mxs/clock-mx28.c
@@ -804,11 +804,11 @@ int __init mx28_clocks_init(void)
         clk_set_parent(&ssp0_clk, &ref_io0_clk);
         clk_set_parent(&ssp1_clk, &ref_io0_clk);
 
-        clk_enable(&cpu_clk);
-        clk_enable(&hbus_clk);
-        clk_enable(&xbus_clk);
-        clk_enable(&emi_clk);
-        clk_enable(&uart_clk);
+        clk_prepare_enable(&cpu_clk);
+        clk_prepare_enable(&hbus_clk);
+        clk_prepare_enable(&xbus_clk);
+        clk_prepare_enable(&emi_clk);
+        clk_prepare_enable(&uart_clk);
 
         clk_set_parent(&lcdif_clk, &ref_pix_clk);
         clk_set_parent(&saif0_clk, &pll0_clk);
diff --git a/arch/arm/mach-mxs/clock.c b/arch/arm/mach-mxs/clock.c
index a7093c88e6a6..97a6f4acc6cc 100644
--- a/arch/arm/mach-mxs/clock.c
+++ b/arch/arm/mach-mxs/clock.c
@@ -74,10 +74,15 @@ static int __clk_enable(struct clk *clk)
         return 0;
 }
 
-/* This function increments the reference count on the clock and enables the
- * clock if not already enabled. The parent clock tree is recursively enabled
+/*
+ * The clk_enable/clk_disable could be called by drivers in atomic context,
+ * so they should not really hold mutex.  Instead, clk_prepare/clk_unprepare
+ * can hold a mutex, as the pair will only be called in non-atomic context.
+ * Before migrating to common clk framework, we can have __clk_enable and
+ * __clk_disable called in clk_prepare/clk_unprepare with mutex held and
+ * leave clk_enable/clk_disable as the dummy functions.
  */
-int clk_enable(struct clk *clk)
+int clk_prepare(struct clk *clk)
 {
         int ret = 0;
 
@@ -90,13 +95,9 @@ int clk_enable(struct clk *clk)
 
         return ret;
 }
-EXPORT_SYMBOL(clk_enable);
+EXPORT_SYMBOL(clk_prepare);
 
-/* This function decrements the reference count on the clock and disables
- * the clock when reference count is 0. The parent clock tree is
- * recursively disabled
- */
-void clk_disable(struct clk *clk)
+void clk_unprepare(struct clk *clk)
 {
         if (clk == NULL || IS_ERR(clk))
                 return;
@@ -105,6 +106,18 @@ void clk_disable(struct clk *clk)
         __clk_disable(clk);
         mutex_unlock(&clocks_mutex);
 }
+EXPORT_SYMBOL(clk_unprepare);
+
+int clk_enable(struct clk *clk)
+{
+        return 0;
+}
+EXPORT_SYMBOL(clk_enable);
+
+void clk_disable(struct clk *clk)
+{
+        /* nothing to do */
+}
 EXPORT_SYMBOL(clk_disable);
 
 /* Retrieve the *current* clock rate. If the clock itself
@@ -166,7 +179,7 @@ int clk_set_parent(struct clk *clk, struct clk *parent)
                 return ret;
 
         if (clk->usecount)
-                clk_enable(parent);
+                clk_prepare_enable(parent);
 
         mutex_lock(&clocks_mutex);
         ret = clk->set_parent(clk, parent);
diff --git a/arch/arm/mach-mxs/mach-mx28evk.c b/arch/arm/mach-mxs/mach-mx28evk.c
index eb0597be4e23..fdb0a5664dd6 100644
--- a/arch/arm/mach-mxs/mach-mx28evk.c
+++ b/arch/arm/mach-mxs/mach-mx28evk.c
@@ -229,7 +229,7 @@ static void __init mx28evk_fec_reset(void)
         /* Enable fec phy clock */
         clk = clk_get_sys("pll2", NULL);
         if (!IS_ERR(clk))
-                clk_enable(clk);
+                clk_prepare_enable(clk);
 
         /* Power up fec phy */
         ret = gpio_request(MX28EVK_FEC_PHY_POWER, "fec-phy-power");
diff --git a/arch/arm/mach-mxs/system.c b/arch/arm/mach-mxs/system.c
index b936633b7682..54f91ad1c965 100644
--- a/arch/arm/mach-mxs/system.c
+++ b/arch/arm/mach-mxs/system.c
@@ -66,7 +66,7 @@ static int __init mxs_arch_reset_init(void)
 
         clk = clk_get_sys("rtc", NULL);
         if (!IS_ERR(clk))
-                clk_enable(clk);
+                clk_prepare_enable(clk);
 
         return 0;
 }
diff --git a/arch/arm/mach-mxs/timer.c b/arch/arm/mach-mxs/timer.c
index cace0d2e5a55..564a63279f18 100644
--- a/arch/arm/mach-mxs/timer.c
+++ b/arch/arm/mach-mxs/timer.c
@@ -245,7 +245,7 @@ static int __init mxs_clocksource_init(struct clk *timer_clk)
 
 void __init mxs_timer_init(struct clk *timer_clk, int irq)
 {
-        clk_enable(timer_clk);
+        clk_prepare_enable(timer_clk);
 
         /*
          * Initialize timers to a known state