clk: sunxi-ng: Add maximum rate constraint to NM PLLs

On some NM PLLs, frequency can be set above PLL working range.

Add a constraint for maximum supported rate. This way, drivers can
specify which is maximum allowed rate for PLL.

Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>

2 files changed, 37 insertions, 0 deletions

diff --git a/drivers/clk/sunxi-ng/ccu_nm.c b/drivers/clk/sunxi-ng/ccu_nm.c
index 4e2073307f34..6fe3c14f7b2d 100644
--- a/drivers/clk/sunxi-ng/ccu_nm.c
+++ b/drivers/clk/sunxi-ng/ccu_nm.c
@@ -124,6 +124,13 @@ static long ccu_nm_round_rate(struct clk_hw *hw, unsigned long rate,
                 return rate;
         }
 
+        if (nm->max_rate && rate > nm->max_rate) {
+                rate = nm->max_rate;
+                if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV)
+                        rate /= nm->fixed_post_div;
+                return rate;
+        }
+
         if (ccu_frac_helper_has_rate(&nm->common, &nm->frac, rate)) {
                 if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV)
                         rate /= nm->fixed_post_div;
diff --git a/drivers/clk/sunxi-ng/ccu_nm.h b/drivers/clk/sunxi-ng/ccu_nm.h
index 1d8b459c50b7..de232f2199a6 100644
--- a/drivers/clk/sunxi-ng/ccu_nm.h
+++ b/drivers/clk/sunxi-ng/ccu_nm.h
@@ -38,6 +38,7 @@ struct ccu_nm {
 
         unsigned int            fixed_post_div;
         unsigned int            min_rate;
+        unsigned int            max_rate;
 
         struct ccu_common       common;
 };
@@ -115,6 +116,35 @@ struct ccu_nm {
                 },                                                      \
         }
 
+#define SUNXI_CCU_NM_WITH_FRAC_GATE_LOCK_MIN_MAX(_struct, _name,        \
+                                                 _parent, _reg,         \
+                                                 _min_rate, _max_rate,  \
+                                                 _nshift, _nwidth,      \
+                                                 _mshift, _mwidth,      \
+                                                 _frac_en, _frac_sel,   \
+                                                 _frac_rate_0,          \
+                                                 _frac_rate_1,          \
+                                                 _gate, _lock, _flags)  \
+        struct ccu_nm _struct = {                                       \
+                .enable         = _gate,                                \
+                .lock           = _lock,                                \
+                .n              = _SUNXI_CCU_MULT(_nshift, _nwidth),    \
+                .m              = _SUNXI_CCU_DIV(_mshift, _mwidth),     \
+                .frac           = _SUNXI_CCU_FRAC(_frac_en, _frac_sel,  \
+                                                  _frac_rate_0,         \
+                                                  _frac_rate_1),        \
+                .min_rate       = _min_rate,                            \
+                .max_rate       = _max_rate,                            \
+                .common         = {                                     \
+                        .reg            = _reg,                         \
+                        .features       = CCU_FEATURE_FRACTIONAL,       \
+                        .hw.init        = CLK_HW_INIT(_name,            \
+                                                      _parent,          \
+                                                      &ccu_nm_ops,      \
+                                                      _flags),          \
+                },                                                      \
+        }
+
 #define SUNXI_CCU_NM_WITH_GATE_LOCK(_struct, _name, _parent, _reg,      \
                                     _nshift, _nwidth,                   \
                                     _mshift, _mwidth,                   \