clk: meson: clk-pll: remove od parameters

Remove od parameters from pll clocks and add post dividers clocks
instead. Some clock, especially the one which feature several ods,
may provide output between those ods. Also, some drivers, such
as the hdmi driver, may require a more detailed control of the
clock dividers, compared to what CCF would perform automatically.

One added benefit of removing ods is that it also greatly reduce the
size of the rate parameter tables.

In the future, we could possibly take the predivider 'n' out of this
driver as well. To do so, we will need to understand the constraints
for the PLL to lock and whether or not it depends on the input clock
rate.

Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Tested-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>

1 files changed, 13 insertions, 27 deletions

diff --git a/drivers/clk/meson/clk-pll.c b/drivers/clk/meson/clk-pll.c
index 8aaefe67025f..348a866f09eb 100644
--- a/drivers/clk/meson/clk-pll.c
+++ b/drivers/clk/meson/clk-pll.c
@@ -11,15 +11,19 @@
  * In the most basic form, a Meson PLL is composed as follows:
  *
  *                     PLL
- *      +------------------------------+
- *      |                              |
- * in -----[ /N ]---[ *M ]---[ >>OD ]----->> out
- *      |         ^        ^           |
- *      +------------------------------+
- *                |        |
- *               FREF     VCO
+ *        +--------------------------------+
+ *        |                                |
+ *        |             +--+               |
+ *  in >>-----[ /N ]--->|  |      +-----+  |
+ *        |             |  |------| DCO |---->> out
+ *        |  +--------->|  |      +--v--+  |
+ *        |  |          +--+         |     |
+ *        |  |                       |     |
+ *        |  +--[ *(M + (F/Fmax) ]<--+     |
+ *        |                                |
+ *        +--------------------------------+
  *
- * out = in * (m + frac / frac_max) / (n << sum(ods))
+ * out = in * (m + frac / frac_max) / n
  */
 
 #include <linux/clk-provider.h>
@@ -46,7 +50,6 @@ static unsigned long __pll_params_to_rate(unsigned long parent_rate,
 					  struct meson_clk_pll_data *pll)
 {
 	u64 rate = (u64)parent_rate * pllt->m;
-	unsigned int od = pllt->od + pllt->od2 + pllt->od3;
 
 	if (frac && MESON_PARM_APPLICABLE(&pll->frac)) {
 		u64 frac_rate = (u64)parent_rate * frac;
@@ -55,7 +58,7 @@ static unsigned long __pll_params_to_rate(unsigned long parent_rate,
 					 (1 << pll->frac.width));
 	}
 
-	return DIV_ROUND_UP_ULL(rate, pllt->n << od);
+	return DIV_ROUND_UP_ULL(rate, pllt->n);
 }
 
 static unsigned long meson_clk_pll_recalc_rate(struct clk_hw *hw,
@@ -68,15 +71,6 @@ static unsigned long meson_clk_pll_recalc_rate(struct clk_hw *hw,
 
 	pllt.n = meson_parm_read(clk->map, &pll->n);
 	pllt.m = meson_parm_read(clk->map, &pll->m);
-	pllt.od = meson_parm_read(clk->map, &pll->od);
-
-	pllt.od2 = MESON_PARM_APPLICABLE(&pll->od2) ?
-		meson_parm_read(clk->map, &pll->od2) :
-		0;
-
-	pllt.od3 = MESON_PARM_APPLICABLE(&pll->od3) ?
-		meson_parm_read(clk->map, &pll->od3) :
-		0;
 
 	frac = MESON_PARM_APPLICABLE(&pll->frac) ?
 		meson_parm_read(clk->map, &pll->frac) :
@@ -93,8 +87,6 @@ static u16 __pll_params_with_frac(unsigned long rate,
 	u16 frac_max = (1 << pll->frac.width);
 	u64 val = (u64)rate * pllt->n;
 
-	val <<= pllt->od + pllt->od2 + pllt->od3;
-
 	if (pll->flags & CLK_MESON_PLL_ROUND_CLOSEST)
 		val = DIV_ROUND_CLOSEST_ULL(val * frac_max, parent_rate);
 	else
@@ -242,13 +234,7 @@ static int meson_clk_pll_set_rate(struct clk_hw *hw, unsigned long rate,
 
 	meson_parm_write(clk->map, &pll->n, pllt->n);
 	meson_parm_write(clk->map, &pll->m, pllt->m);
-	meson_parm_write(clk->map, &pll->od, pllt->od);
-
-	if (MESON_PARM_APPLICABLE(&pll->od2))
-		meson_parm_write(clk->map, &pll->od2, pllt->od2);
 
-	if (MESON_PARM_APPLICABLE(&pll->od3))
-		meson_parm_write(clk->map, &pll->od3, pllt->od3);
 
 	if (MESON_PARM_APPLICABLE(&pll->frac)) {
 		frac = __pll_params_with_frac(rate, parent_rate, pllt, pll);