clk: bcm281xx: add clock policy support

Add support for CCU policy engine control, and also for setting the
mask bits for bus clocks that require a policy change to get
activated.  This includes adding validity checking framework for
CCUs, to validate the policy fields if defined.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

1 files changed, 92 insertions, 0 deletions

diff --git a/drivers/clk/bcm/clk-kona-setup.c b/drivers/clk/bcm/clk-kona-setup.c
index 825a2f2ab052..773ad7c7dd59 100644
--- a/drivers/clk/bcm/clk-kona-setup.c
+++ b/drivers/clk/bcm/clk-kona-setup.c
@@ -25,6 +25,31 @@ LIST_HEAD(ccu_list);	/* The list of set up CCUs */
 
 /* Validity checking */
 
+static bool ccu_data_offsets_valid(struct ccu_data *ccu)
+{
+        struct ccu_policy *ccu_policy = &ccu->policy;
+        u32 limit;
+
+        limit = ccu->range - sizeof(u32);
+        limit = round_down(limit, sizeof(u32));
+        if (ccu_policy_exists(ccu_policy)) {
+                if (ccu_policy->enable.offset > limit) {
+                        pr_err("%s: bad policy enable offset for %s "
+                                        "(%u > %u)\n", __func__,
+                                ccu->name, ccu_policy->enable.offset, limit);
+                        return false;
+                }
+                if (ccu_policy->control.offset > limit) {
+                        pr_err("%s: bad policy control offset for %s "
+                                        "(%u > %u)\n", __func__,
+                                ccu->name, ccu_policy->control.offset, limit);
+                        return false;
+                }
+        }
+
+        return true;
+}
+
 static bool clk_requires_trigger(struct kona_clk *bcm_clk)
 {
         struct peri_clk_data *peri = bcm_clk->u.peri;
@@ -54,6 +79,7 @@ static bool clk_requires_trigger(struct kona_clk *bcm_clk)
 static bool peri_clk_data_offsets_valid(struct kona_clk *bcm_clk)
 {
         struct peri_clk_data *peri;
+        struct bcm_clk_policy *policy;
         struct bcm_clk_gate *gate;
         struct bcm_clk_div *div;
         struct bcm_clk_sel *sel;
@@ -70,6 +96,15 @@ static bool peri_clk_data_offsets_valid(struct kona_clk *bcm_clk)
         limit = range - sizeof(u32);
         limit = round_down(limit, sizeof(u32));
 
+        policy = &peri->policy;
+        if (policy_exists(policy)) {
+                if (policy->offset > limit) {
+                        pr_err("%s: bad policy offset for %s (%u > %u)\n",
+                                __func__, name, policy->offset, limit);
+                        return false;
+                }
+        }
+
         gate = &peri->gate;
         if (gate_exists(gate)) {
                 if (gate->offset > limit) {
@@ -167,6 +202,36 @@ static bool bitfield_valid(u32 shift, u32 width, const char *field_name,
         return true;
 }
 
+static bool
+ccu_policy_valid(struct ccu_policy *ccu_policy, const char *ccu_name)
+{
+        struct bcm_lvm_en *enable = &ccu_policy->enable;
+        struct bcm_policy_ctl *control;
+
+        if (!bit_posn_valid(enable->bit, "policy enable", ccu_name))
+                return false;
+
+        control = &ccu_policy->control;
+        if (!bit_posn_valid(control->go_bit, "policy control GO", ccu_name))
+                return false;
+
+        if (!bit_posn_valid(control->atl_bit, "policy control ATL", ccu_name))
+                return false;
+
+        if (!bit_posn_valid(control->ac_bit, "policy control AC", ccu_name))
+                return false;
+
+        return true;
+}
+
+static bool policy_valid(struct bcm_clk_policy *policy, const char *clock_name)
+{
+        if (!bit_posn_valid(policy->bit, "policy", clock_name))
+                return false;
+
+        return true;
+}
+
 /*
  * All gates, if defined, have a status bit, and for hardware-only
  * gates, that's it.  Gates that can be software controlled also
@@ -312,6 +377,7 @@ static bool
 peri_clk_data_valid(struct kona_clk *bcm_clk)
 {
         struct peri_clk_data *peri;
+        struct bcm_clk_policy *policy;
         struct bcm_clk_gate *gate;
         struct bcm_clk_sel *sel;
         struct bcm_clk_div *div;
@@ -331,6 +397,11 @@ peri_clk_data_valid(struct kona_clk *bcm_clk)
 
         peri = bcm_clk->u.peri;
         name = bcm_clk->init_data.name;
+
+        policy = &peri->policy;
+        if (policy_exists(policy) && !policy_valid(policy, name))
+                return false;
+
         gate = &peri->gate;
         if (gate_exists(gate) && !gate_valid(gate, "gate", name))
                 return false;
@@ -679,6 +750,21 @@ static void kona_ccu_teardown(struct ccu_data *ccu)
         ccu->base = NULL;
 }
 
+static bool ccu_data_valid(struct ccu_data *ccu)
+{
+        struct ccu_policy *ccu_policy;
+
+        if (!ccu_data_offsets_valid(ccu))
+                return false;
+
+        ccu_policy = &ccu->policy;
+        if (ccu_policy_exists(ccu_policy))
+                if (!ccu_policy_valid(ccu_policy, ccu->name))
+                        return false;
+
+        return true;
+}
+
 /*
  * Set up a CCU.  Call the provided ccu_clks_setup callback to
  * initialize the array of clocks provided by the CCU.
@@ -718,6 +804,12 @@ void __init kona_dt_ccu_setup(struct ccu_data *ccu,
         }
 
         ccu->range = (u32)range;
+
+        if (!ccu_data_valid(ccu)) {
+                pr_err("%s: ccu data not valid for %s\n", __func__, node->name);
+                goto out_err;
+        }
+
         ccu->base = ioremap(res.start, ccu->range);
         if (!ccu->base) {
                 pr_err("%s: unable to map CCU registers for %s\n", __func__,