Davinci: support LPSC SwRstDisable state

The current clock control code always gates the clock (PSC state Disable = 2)
on clk_disable().  Some on-chip peripherals (e.g. LCD controller on TNETV107X)
need to be put into SwRstDisable = 0 on clock disable, to maintain
hardware sanity.

This patch extends the davinci_psc_config() arguments to pass in the desired
module state instead of a boolean enable/disable.  Further, clk_disable() now
checks for the PSC_SWRSTDISABLE clk flag before selecting the target state.

Signed-off-by: Cyril Chemparathy <cyril@ti.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>

4 files changed, 21 insertions, 9 deletions

diff --git a/arch/arm/mach-davinci/clock.c b/arch/arm/mach-davinci/clock.c
index 058c77f72a07..5de60ae57903 100644
--- a/arch/arm/mach-davinci/clock.c
+++ b/arch/arm/mach-davinci/clock.c
@@ -43,7 +43,8 @@ static void __clk_enable(struct clk *clk)
         if (clk->parent)
                 __clk_enable(clk->parent);
         if (clk->usecount++ == 0 && (clk->flags & CLK_PSC))
-                davinci_psc_config(psc_domain(clk), clk->gpsc, clk->lpsc, 1);
+                davinci_psc_config(psc_domain(clk), clk->gpsc, clk->lpsc,
+                                PSC_STATE_ENABLE);
 }
 
 static void __clk_disable(struct clk *clk)
@@ -52,7 +53,9 @@ static void __clk_disable(struct clk *clk)
                 return;
         if (--clk->usecount == 0 && !(clk->flags & CLK_PLL) &&
             (clk->flags & CLK_PSC))
-                davinci_psc_config(psc_domain(clk), clk->gpsc, clk->lpsc, 0);
+                davinci_psc_config(psc_domain(clk), clk->gpsc, clk->lpsc,
+                                (clk->flags & PSC_SWRSTDISABLE) ?
+                                PSC_STATE_SWRSTDISABLE : PSC_STATE_DISABLE);
         if (clk->parent)
                 __clk_disable(clk->parent);
 }
@@ -234,7 +237,10 @@ static int __init clk_disable_unused(void)
                         continue;
 
                 pr_info("Clocks: disable unused %s\n", ck->name);
-                davinci_psc_config(psc_domain(ck), ck->gpsc, ck->lpsc, 0);
+
+                davinci_psc_config(psc_domain(ck), ck->gpsc, ck->lpsc,
+                                (ck->flags & PSC_SWRSTDISABLE) ?
+                                PSC_STATE_SWRSTDISABLE : PSC_STATE_DISABLE);
         }
         spin_unlock_irq(&clockfw_lock);
 
diff --git a/arch/arm/mach-davinci/clock.h b/arch/arm/mach-davinci/clock.h
index aa0a61150325..53a0f7b90119 100644
--- a/arch/arm/mach-davinci/clock.h
+++ b/arch/arm/mach-davinci/clock.h
@@ -101,10 +101,11 @@ struct clk {
 
 /* Clock flags: SoC-specific flags start at BIT(16) */
 #define ALWAYS_ENABLED          BIT(1)
-#define CLK_PSC                 BIT(2)
-#define PSC_DSP                 BIT(3) /* PSC uses DSP domain, not ARM */
+#define CLK_PSC                 BIT(2)
+#define PSC_DSP                 BIT(3) /* PSC uses DSP domain, not ARM */
 #define CLK_PLL                 BIT(4) /* PLL-derived clock */
-#define PRE_PLL                 BIT(5) /* source is before PLL mult/div */
+#define PRE_PLL                 BIT(5) /* source is before PLL mult/div */
+#define PSC_SWRSTDISABLE        BIT(6) /* Disable state is SwRstDisable */
 
 #define CLK(dev, con, ck)       \
         {                       \
diff --git a/arch/arm/mach-davinci/include/mach/psc.h b/arch/arm/mach-davinci/include/mach/psc.h
index 651f6d8158fa..7dd2962ad586 100644
--- a/arch/arm/mach-davinci/include/mach/psc.h
+++ b/arch/arm/mach-davinci/include/mach/psc.h
@@ -189,13 +189,19 @@
 #define MDSTAT          0x800
 #define MDCTL           0xA00
 
+/* PSC module states */
+#define PSC_STATE_SWRSTDISABLE  0
+#define PSC_STATE_SYNCRST       1
+#define PSC_STATE_DISABLE       2
+#define PSC_STATE_ENABLE        3
+
 #define MDSTAT_STATE_MASK 0x1f
 
 #ifndef __ASSEMBLER__
 
 extern int davinci_psc_is_clk_active(unsigned int ctlr, unsigned int id);
 extern void davinci_psc_config(unsigned int domain, unsigned int ctlr,
-                unsigned int id, char enable);
+                unsigned int id, u32 next_state);
 
 #endif
 
diff --git a/arch/arm/mach-davinci/psc.c b/arch/arm/mach-davinci/psc.c
index adf6b5c7f1e5..d7cb438c4df6 100644
--- a/arch/arm/mach-davinci/psc.c
+++ b/arch/arm/mach-davinci/psc.c
@@ -47,12 +47,11 @@ int __init davinci_psc_is_clk_active(unsigned int ctlr, unsigned int id)
 
 /* Enable or disable a PSC domain */
 void davinci_psc_config(unsigned int domain, unsigned int ctlr,
-                unsigned int id, char enable)
+                unsigned int id, u32 next_state)
 {
         u32 epcpr, ptcmd, ptstat, pdstat, pdctl1, mdstat, mdctl;
         void __iomem *psc_base;
         struct davinci_soc_info *soc_info = &davinci_soc_info;
-        u32 next_state = enable ? 0x3 : 0x2; /* 0x3 enables, 0x2 disables */
 
         if (!soc_info->psc_bases || (ctlr >= soc_info->psc_bases_num)) {
                 pr_warning("PSC: Bad psc data: 0x%x[%d]\n",