OMAP: clock: fix configuration of J-Type DPLLs to work for OMAP3 and OMAP4

J-Type DPLLs have additional configuration parameters that need to
be programmed when setting the multipler and divider for the DPLL.
These parameters being the sigma delta divider (SD_DIV) for the DPLL
and the digital controlled oscillator (DCO) to be used by the DPLL.

The current code is implemented specifically to configure the
OMAP3630 PER J-Type DPLL. The OMAP4430 USB DPLL is also a J-Type DPLL
and so this code needs to be updated to work for both OMAP3 and OMAP4
devices and any other future devices that have J-TYPE DPLLs.

For the OMAP3630 PER DPLL both the SD_DIV and DCO paramenters are
used but for the OMAP4430 USB DPLL only the SD_DIV field is used.
The current implementation will only program the SD_DIV and DCO
fields if the DPLL has both and hence this does not work for
OMAP4430.

In order to make the code more generic add two new fields to the
dpll_data structure for the SD_DIV field and DCO field bit-masks
and only program these fields if the masks are defined for a specific
DPLL. This simplifies the code and allows us to remove the flag
DPLL_NO_DCO_SEL.

Tested on OMAP36xx Zoom3 and OMAP4 Blaze.

Signed-off-by: Jon Hunter <jon-hunter@ti.com>
[paul@pwsan.com: removed explicit inlining and added '_' prefix on lookup_*()
 functions; added testing info to commit message; added 35xx comments back in]
Signed-off-by: Paul Walmsley <paul@pwsan.com>

1 files changed, 35 insertions, 18 deletions

diff --git a/arch/arm/mach-omap2/dpll3xxx.c b/arch/arm/mach-omap2/dpll3xxx.c
index cb535ee4e8fe..5df9f53e6d01 100644
--- a/arch/arm/mach-omap2/dpll3xxx.c
+++ b/arch/arm/mach-omap2/dpll3xxx.c
@@ -223,10 +223,9 @@ static int _omap3_noncore_dpll_stop(struct clk *clk)
 }
 
 /**
- * lookup_dco_sddiv -  Set j-type DPLL4 compensation variables
+ * _lookup_dco - Lookup DCO used by j-type DPLL
  * @clk: pointer to a DPLL struct clk
  * @dco: digital control oscillator selector
- * @sd_div: target sigma-delta divider
  * @m: DPLL multiplier to set
  * @n: DPLL divider to set
  *
@@ -235,11 +234,9 @@ static int _omap3_noncore_dpll_stop(struct clk *clk)
  * XXX This code is not needed for 3430/AM35xx; can it be optimized
  * out in non-multi-OMAP builds for those chips?
  */
-static void lookup_dco_sddiv(struct clk *clk, u8 *dco, u8 *sd_div, u16 m,
-                             u8 n)
+static void _lookup_dco(struct clk *clk, u8 *dco, u16 m, u8 n)
 {
-        unsigned long fint, clkinp, sd; /* watch out for overflow */
-        int mod1, mod2;
+        unsigned long fint, clkinp; /* watch out for overflow */
 
         clkinp = clk->parent->rate;
         fint = (clkinp / n) * m;
@@ -248,6 +245,27 @@ static void lookup_dco_sddiv(struct clk *clk, u8 *dco, u8 *sd_div, u16 m,
                 *dco = 2;
         else
                 *dco = 4;
+}
+
+/**
+ * _lookup_sddiv - Calculate sigma delta divider for j-type DPLL
+ * @clk: pointer to a DPLL struct clk
+ * @sd_div: target sigma-delta divider
+ * @m: DPLL multiplier to set
+ * @n: DPLL divider to set
+ *
+ * See 36xx TRM section 3.5.3.3.3.2 "Type B DPLL (Low-Jitter)"
+ *
+ * XXX This code is not needed for 3430/AM35xx; can it be optimized
+ * out in non-multi-OMAP builds for those chips?
+ */
+static void _lookup_sddiv(struct clk *clk, u8 *sd_div, u16 m, u8 n)
+{
+        unsigned long clkinp, sd; /* watch out for overflow */
+        int mod1, mod2;
+
+        clkinp = clk->parent->rate;
+
         /*
          * target sigma-delta to near 250MHz
          * sd = ceil[(m/(n+1)) * (clkinp_MHz / 250)]
@@ -276,6 +294,7 @@ static void lookup_dco_sddiv(struct clk *clk, u8 *dco, u8 *sd_div, u16 m,
 static int omap3_noncore_dpll_program(struct clk *clk, u16 m, u8 n, u16 freqsel)
 {
         struct dpll_data *dd = clk->dpll_data;
+        u8 dco, sd_div;
         u32 v;
 
         /* 3430 ES2 TRM: 4.7.6.9 DPLL Programming Sequence */
@@ -298,18 +317,16 @@ static int omap3_noncore_dpll_program(struct clk *clk, u16 m, u8 n, u16 freqsel)
         v |= m << __ffs(dd->mult_mask);
         v |= (n - 1) << __ffs(dd->div1_mask);
 
-        /*
-         * XXX This code is not needed for 3430/AM35XX; can it be optimized
-         * out in non-multi-OMAP builds for those chips?
-         */
-        if ((dd->flags & DPLL_J_TYPE) && !(dd->flags & DPLL_NO_DCO_SEL)) {
-                u8 dco, sd_div;
-                lookup_dco_sddiv(clk, &dco, &sd_div, m, n);
-                /* XXX This probably will need revision for OMAP4 */
-                v &= ~(OMAP3630_PERIPH_DPLL_DCO_SEL_MASK
-                        | OMAP3630_PERIPH_DPLL_SD_DIV_MASK);
-                v |= dco << __ffs(OMAP3630_PERIPH_DPLL_DCO_SEL_MASK);
-                v |= sd_div << __ffs(OMAP3630_PERIPH_DPLL_SD_DIV_MASK);
+        /* Configure dco and sd_div for dplls that have these fields */
+        if (dd->dco_mask) {
+                _lookup_dco(clk, &dco, m, n);
+                v &= ~(dd->dco_mask);
+                v |= dco << __ffs(dd->dco_mask);
+        }
+        if (dd->sddiv_mask) {
+                _lookup_sddiv(clk, &sd_div, m, n);
+                v &= ~(dd->sddiv_mask);
+                v |= sd_div << __ffs(dd->sddiv_mask);
         }
 
         __raw_writel(v, dd->mult_div1_reg);