clk: ux500: Support is_prepared callback for clk-prcmu

To be able to gate unused prcmu clocks from the clk_disable_unused sequence,
clk-prcmu now implements the is_prepared callback.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

1 files changed, 80 insertions, 54 deletions

diff --git a/drivers/clk/ux500/clk-prcmu.c b/drivers/clk/ux500/clk-prcmu.c
index 74faa7e3cf59..9d832567c6be 100644
--- a/drivers/clk/ux500/clk-prcmu.c
+++ b/drivers/clk/ux500/clk-prcmu.c
@@ -20,15 +20,23 @@
 struct clk_prcmu {
         struct clk_hw hw;
         u8 cg_sel;
+        int is_prepared;
         int is_enabled;
+        int opp_requested;
 };
 
 /* PRCMU clock operations. */
 
 static int clk_prcmu_prepare(struct clk_hw *hw)
 {
+        int ret;
         struct clk_prcmu *clk = to_clk_prcmu(hw);
-        return prcmu_request_clock(clk->cg_sel, true);
+
+        ret = prcmu_request_clock(clk->cg_sel, true);
+        if (!ret)
+                clk->is_prepared = 1;
+
+        return ret;;
 }
 
 static void clk_prcmu_unprepare(struct clk_hw *hw)
@@ -37,6 +45,14 @@ static void clk_prcmu_unprepare(struct clk_hw *hw)
         if (prcmu_request_clock(clk->cg_sel, false))
                 pr_err("clk_prcmu: %s failed to disable %s.\n", __func__,
                         hw->init->name);
+        else
+                clk->is_prepared = 0;
+}
+
+static int clk_prcmu_is_prepared(struct clk_hw *hw)
+{
+        struct clk_prcmu *clk = to_clk_prcmu(hw);
+        return clk->is_prepared;
 }
 
 static int clk_prcmu_enable(struct clk_hw *hw)
@@ -79,58 +95,52 @@ static int clk_prcmu_set_rate(struct clk_hw *hw, unsigned long rate,
         return prcmu_set_clock_rate(clk->cg_sel, rate);
 }
 
-static int request_ape_opp100(bool enable)
-{
-        static int reqs;
-        int err = 0;
-
-        if (enable) {
-                if (!reqs)
-                        err = prcmu_qos_add_requirement(PRCMU_QOS_APE_OPP,
-                                                        "clock", 100);
-                if (!err)
-                        reqs++;
-        } else {
-                reqs--;
-                if (!reqs)
-                        prcmu_qos_remove_requirement(PRCMU_QOS_APE_OPP,
-                                                "clock");
-        }
-        return err;
-}
-
 static int clk_prcmu_opp_prepare(struct clk_hw *hw)
 {
         int err;
         struct clk_prcmu *clk = to_clk_prcmu(hw);
 
-        err = request_ape_opp100(true);
-        if (err) {
-                pr_err("clk_prcmu: %s failed to request APE OPP100 for %s.\n",
-                        __func__, hw->init->name);
-                return err;
+        if (!clk->opp_requested) {
+                err = prcmu_qos_add_requirement(PRCMU_QOS_APE_OPP,
+                                                (char *)__clk_get_name(hw->clk),
+                                                100);
+                if (err) {
+                        pr_err("clk_prcmu: %s fail req APE OPP for %s.\n",
+                                __func__, hw->init->name);
+                        return err;
+                }
+                clk->opp_requested = 1;
         }
 
         err = prcmu_request_clock(clk->cg_sel, true);
-        if (err)
-                request_ape_opp100(false);
+        if (err) {
+                prcmu_qos_remove_requirement(PRCMU_QOS_APE_OPP,
+                                        (char *)__clk_get_name(hw->clk));
+                clk->opp_requested = 0;
+                return err;
+        }
 
-        return err;
+        clk->is_prepared = 1;
+        return 0;
 }
 
 static void clk_prcmu_opp_unprepare(struct clk_hw *hw)
 {
         struct clk_prcmu *clk = to_clk_prcmu(hw);
 
-        if (prcmu_request_clock(clk->cg_sel, false))
-                goto out_error;
-        if (request_ape_opp100(false))
-                goto out_error;
-        return;
-
-out_error:
-        pr_err("clk_prcmu: %s failed to disable %s.\n", __func__,
-                hw->init->name);
+        if (prcmu_request_clock(clk->cg_sel, false)) {
+                pr_err("clk_prcmu: %s failed to disable %s.\n", __func__,
+                        hw->init->name);
+                return;
+        }
+
+        if (clk->opp_requested) {
+                prcmu_qos_remove_requirement(PRCMU_QOS_APE_OPP,
+                                        (char *)__clk_get_name(hw->clk));
+                clk->opp_requested = 0;
+        }
+
+        clk->is_prepared = 0;
 }
 
 static int clk_prcmu_opp_volt_prepare(struct clk_hw *hw)
@@ -138,38 +148,49 @@ static int clk_prcmu_opp_volt_prepare(struct clk_hw *hw)
         int err;
         struct clk_prcmu *clk = to_clk_prcmu(hw);
 
-        err = prcmu_request_ape_opp_100_voltage(true);
-        if (err) {
-                pr_err("clk_prcmu: %s failed to request APE OPP VOLT for %s.\n",
-                        __func__, hw->init->name);
-                return err;
+        if (!clk->opp_requested) {
+                err = prcmu_request_ape_opp_100_voltage(true);
+                if (err) {
+                        pr_err("clk_prcmu: %s fail req APE OPP VOLT for %s.\n",
+                                __func__, hw->init->name);
+                        return err;
+                }
+                clk->opp_requested = 1;
         }
 
         err = prcmu_request_clock(clk->cg_sel, true);
-        if (err)
+        if (err) {
                 prcmu_request_ape_opp_100_voltage(false);
+                clk->opp_requested = 0;
+                return err;
+        }
 
-        return err;
+        clk->is_prepared = 1;
+        return 0;
 }
 
 static void clk_prcmu_opp_volt_unprepare(struct clk_hw *hw)
 {
         struct clk_prcmu *clk = to_clk_prcmu(hw);
 
-        if (prcmu_request_clock(clk->cg_sel, false))
-                goto out_error;
-        if (prcmu_request_ape_opp_100_voltage(false))
-                goto out_error;
-        return;
-
-out_error:
-        pr_err("clk_prcmu: %s failed to disable %s.\n", __func__,
-                hw->init->name);
+        if (prcmu_request_clock(clk->cg_sel, false)) {
+                pr_err("clk_prcmu: %s failed to disable %s.\n", __func__,
+                        hw->init->name);
+                return;
+        }
+
+        if (clk->opp_requested) {
+                prcmu_request_ape_opp_100_voltage(false);
+                clk->opp_requested = 0;
+        }
+
+        clk->is_prepared = 0;
 }
 
 static struct clk_ops clk_prcmu_scalable_ops = {
         .prepare = clk_prcmu_prepare,
         .unprepare = clk_prcmu_unprepare,
+        .is_prepared = clk_prcmu_is_prepared,
         .enable = clk_prcmu_enable,
         .disable = clk_prcmu_disable,
         .is_enabled = clk_prcmu_is_enabled,
@@ -181,6 +202,7 @@ static struct clk_ops clk_prcmu_scalable_ops = {
 static struct clk_ops clk_prcmu_gate_ops = {
         .prepare = clk_prcmu_prepare,
         .unprepare = clk_prcmu_unprepare,
+        .is_prepared = clk_prcmu_is_prepared,
         .enable = clk_prcmu_enable,
         .disable = clk_prcmu_disable,
         .is_enabled = clk_prcmu_is_enabled,
@@ -202,6 +224,7 @@ static struct clk_ops clk_prcmu_rate_ops = {
 static struct clk_ops clk_prcmu_opp_gate_ops = {
         .prepare = clk_prcmu_opp_prepare,
         .unprepare = clk_prcmu_opp_unprepare,
+        .is_prepared = clk_prcmu_is_prepared,
         .enable = clk_prcmu_enable,
         .disable = clk_prcmu_disable,
         .is_enabled = clk_prcmu_is_enabled,
@@ -211,6 +234,7 @@ static struct clk_ops clk_prcmu_opp_gate_ops = {
 static struct clk_ops clk_prcmu_opp_volt_scalable_ops = {
         .prepare = clk_prcmu_opp_volt_prepare,
         .unprepare = clk_prcmu_opp_volt_unprepare,
+        .is_prepared = clk_prcmu_is_prepared,
         .enable = clk_prcmu_enable,
         .disable = clk_prcmu_disable,
         .is_enabled = clk_prcmu_is_enabled,
@@ -242,7 +266,9 @@ static struct clk *clk_reg_prcmu(const char *name,
         }
 
         clk->cg_sel = cg_sel;
+        clk->is_prepared = 1;
         clk->is_enabled = 1;
+        clk->opp_requested = 0;
         /* "rate" can be used for changing the initial frequency */
         if (rate)
                 prcmu_set_clock_rate(cg_sel, rate);