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path: root/drivers/clk/bcm/clk-kona.c
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Diffstat (limited to 'drivers/clk/bcm/clk-kona.c')
-rw-r--r--drivers/clk/bcm/clk-kona.c330
1 files changed, 289 insertions, 41 deletions
diff --git a/drivers/clk/bcm/clk-kona.c b/drivers/clk/bcm/clk-kona.c
index e3d339e0830..95af2e665dd 100644
--- a/drivers/clk/bcm/clk-kona.c
+++ b/drivers/clk/bcm/clk-kona.c
@@ -16,6 +16,14 @@
#include <linux/delay.h>
+/*
+ * "Policies" affect the frequencies of bus clocks provided by a
+ * CCU. (I believe these polices are named "Deep Sleep", "Economy",
+ * "Normal", and "Turbo".) A lower policy number has lower power
+ * consumption, and policy 2 is the default.
+ */
+#define CCU_POLICY_COUNT 4
+
#define CCU_ACCESS_PASSWORD 0xA5A500
#define CLK_GATE_DELAY_LOOP 2000
@@ -61,7 +69,7 @@ u64 do_div_round_closest(u64 dividend, unsigned long divisor)
/* Convert a divider into the scaled divisor value it represents. */
static inline u64 scaled_div_value(struct bcm_clk_div *div, u32 reg_div)
{
- return (u64)reg_div + ((u64)1 << div->frac_width);
+ return (u64)reg_div + ((u64)1 << div->u.s.frac_width);
}
/*
@@ -77,7 +85,7 @@ u64 scaled_div_build(struct bcm_clk_div *div, u32 div_value, u32 billionths)
BUG_ON(billionths >= BILLION);
combined = (u64)div_value * BILLION + billionths;
- combined <<= div->frac_width;
+ combined <<= div->u.s.frac_width;
return do_div_round_closest(combined, BILLION);
}
@@ -87,7 +95,7 @@ static inline u64
scaled_div_min(struct bcm_clk_div *div)
{
if (divider_is_fixed(div))
- return (u64)div->fixed;
+ return (u64)div->u.fixed;
return scaled_div_value(div, 0);
}
@@ -98,9 +106,9 @@ u64 scaled_div_max(struct bcm_clk_div *div)
u32 reg_div;
if (divider_is_fixed(div))
- return (u64)div->fixed;
+ return (u64)div->u.fixed;
- reg_div = ((u32)1 << div->width) - 1;
+ reg_div = ((u32)1 << div->u.s.width) - 1;
return scaled_div_value(div, reg_div);
}
@@ -115,7 +123,7 @@ divider(struct bcm_clk_div *div, u64 scaled_div)
BUG_ON(scaled_div < scaled_div_min(div));
BUG_ON(scaled_div > scaled_div_max(div));
- return (u32)(scaled_div - ((u64)1 << div->frac_width));
+ return (u32)(scaled_div - ((u64)1 << div->u.s.frac_width));
}
/* Return a rate scaled for use when dividing by a scaled divisor. */
@@ -125,7 +133,7 @@ scale_rate(struct bcm_clk_div *div, u32 rate)
if (divider_is_fixed(div))
return (u64)rate;
- return (u64)rate << div->frac_width;
+ return (u64)rate << div->u.s.frac_width;
}
/* CCU access */
@@ -207,9 +215,154 @@ __ccu_wait_bit(struct ccu_data *ccu, u32 reg_offset, u32 bit, bool want)
return true;
udelay(1);
}
+ pr_warn("%s: %s/0x%04x bit %u was never %s\n", __func__,
+ ccu->name, reg_offset, bit, want ? "set" : "clear");
+
return false;
}
+/* Policy operations */
+
+static bool __ccu_policy_engine_start(struct ccu_data *ccu, bool sync)
+{
+ struct bcm_policy_ctl *control = &ccu->policy.control;
+ u32 offset;
+ u32 go_bit;
+ u32 mask;
+ bool ret;
+
+ /* If we don't need to control policy for this CCU, we're done. */
+ if (!policy_ctl_exists(control))
+ return true;
+
+ offset = control->offset;
+ go_bit = control->go_bit;
+
+ /* Ensure we're not busy before we start */
+ ret = __ccu_wait_bit(ccu, offset, go_bit, false);
+ if (!ret) {
+ pr_err("%s: ccu %s policy engine wouldn't go idle\n",
+ __func__, ccu->name);
+ return false;
+ }
+
+ /*
+ * If it's a synchronous request, we'll wait for the voltage
+ * and frequency of the active load to stabilize before
+ * returning. To do this we select the active load by
+ * setting the ATL bit.
+ *
+ * An asynchronous request instead ramps the voltage in the
+ * background, and when that process stabilizes, the target
+ * load is copied to the active load and the CCU frequency
+ * is switched. We do this by selecting the target load
+ * (ATL bit clear) and setting the request auto-copy (AC bit
+ * set).
+ *
+ * Note, we do NOT read-modify-write this register.
+ */
+ mask = (u32)1 << go_bit;
+ if (sync)
+ mask |= 1 << control->atl_bit;
+ else
+ mask |= 1 << control->ac_bit;
+ __ccu_write(ccu, offset, mask);
+
+ /* Wait for indication that operation is complete. */
+ ret = __ccu_wait_bit(ccu, offset, go_bit, false);
+ if (!ret)
+ pr_err("%s: ccu %s policy engine never started\n",
+ __func__, ccu->name);
+
+ return ret;
+}
+
+static bool __ccu_policy_engine_stop(struct ccu_data *ccu)
+{
+ struct bcm_lvm_en *enable = &ccu->policy.enable;
+ u32 offset;
+ u32 enable_bit;
+ bool ret;
+
+ /* If we don't need to control policy for this CCU, we're done. */
+ if (!policy_lvm_en_exists(enable))
+ return true;
+
+ /* Ensure we're not busy before we start */
+ offset = enable->offset;
+ enable_bit = enable->bit;
+ ret = __ccu_wait_bit(ccu, offset, enable_bit, false);
+ if (!ret) {
+ pr_err("%s: ccu %s policy engine already stopped\n",
+ __func__, ccu->name);
+ return false;
+ }
+
+ /* Now set the bit to stop the engine (NO read-modify-write) */
+ __ccu_write(ccu, offset, (u32)1 << enable_bit);
+
+ /* Wait for indication that it has stopped. */
+ ret = __ccu_wait_bit(ccu, offset, enable_bit, false);
+ if (!ret)
+ pr_err("%s: ccu %s policy engine never stopped\n",
+ __func__, ccu->name);
+
+ return ret;
+}
+
+/*
+ * A CCU has four operating conditions ("policies"), and some clocks
+ * can be disabled or enabled based on which policy is currently in
+ * effect. Such clocks have a bit in a "policy mask" register for
+ * each policy indicating whether the clock is enabled for that
+ * policy or not. The bit position for a clock is the same for all
+ * four registers, and the 32-bit registers are at consecutive
+ * addresses.
+ */
+static bool policy_init(struct ccu_data *ccu, struct bcm_clk_policy *policy)
+{
+ u32 offset;
+ u32 mask;
+ int i;
+ bool ret;
+
+ if (!policy_exists(policy))
+ return true;
+
+ /*
+ * We need to stop the CCU policy engine to allow update
+ * of our policy bits.
+ */
+ if (!__ccu_policy_engine_stop(ccu)) {
+ pr_err("%s: unable to stop CCU %s policy engine\n",
+ __func__, ccu->name);
+ return false;
+ }
+
+ /*
+ * For now, if a clock defines its policy bit we just mark
+ * it "enabled" for all four policies.
+ */
+ offset = policy->offset;
+ mask = (u32)1 << policy->bit;
+ for (i = 0; i < CCU_POLICY_COUNT; i++) {
+ u32 reg_val;
+
+ reg_val = __ccu_read(ccu, offset);
+ reg_val |= mask;
+ __ccu_write(ccu, offset, reg_val);
+ offset += sizeof(u32);
+ }
+
+ /* We're done updating; fire up the policy engine again. */
+ ret = __ccu_policy_engine_start(ccu, true);
+ if (!ret)
+ pr_err("%s: unable to restart CCU %s policy engine\n",
+ __func__, ccu->name);
+
+ return ret;
+}
+
/* Gate operations */
/* Determine whether a clock is gated. CCU lock must be held. */
@@ -374,6 +527,35 @@ static int clk_gate(struct ccu_data *ccu, const char *name,
return -EIO;
}
+/* Hysteresis operations */
+
+/*
+ * If a clock gate requires a turn-off delay it will have
+ * "hysteresis" register bits defined. The first, if set, enables
+ * the delay; and if enabled, the second bit determines whether the
+ * delay is "low" or "high" (1 means high). For now, if it's
+ * defined for a clock, we set it.
+ */
+static bool hyst_init(struct ccu_data *ccu, struct bcm_clk_hyst *hyst)
+{
+ u32 offset;
+ u32 reg_val;
+ u32 mask;
+
+ if (!hyst_exists(hyst))
+ return true;
+
+ offset = hyst->offset;
+ mask = (u32)1 << hyst->en_bit;
+ mask |= (u32)1 << hyst->val_bit;
+
+ reg_val = __ccu_read(ccu, offset);
+ reg_val |= mask;
+ __ccu_write(ccu, offset, reg_val);
+
+ return true;
+}
+
/* Trigger operations */
/*
@@ -398,14 +580,14 @@ static u64 divider_read_scaled(struct ccu_data *ccu, struct bcm_clk_div *div)
u32 reg_div;
if (divider_is_fixed(div))
- return (u64)div->fixed;
+ return (u64)div->u.fixed;
flags = ccu_lock(ccu);
- reg_val = __ccu_read(ccu, div->offset);
+ reg_val = __ccu_read(ccu, div->u.s.offset);
ccu_unlock(ccu, flags);
/* Extract the full divider field from the register value */
- reg_div = bitfield_extract(reg_val, div->shift, div->width);
+ reg_div = bitfield_extract(reg_val, div->u.s.shift, div->u.s.width);
/* Return the scaled divisor value it represents */
return scaled_div_value(div, reg_div);
@@ -433,16 +615,17 @@ static int __div_commit(struct ccu_data *ccu, struct bcm_clk_gate *gate,
* state was defined in the device tree, we just find out
* what its current value is rather than updating it.
*/
- if (div->scaled_div == BAD_SCALED_DIV_VALUE) {
- reg_val = __ccu_read(ccu, div->offset);
- reg_div = bitfield_extract(reg_val, div->shift, div->width);
- div->scaled_div = scaled_div_value(div, reg_div);
+ if (div->u.s.scaled_div == BAD_SCALED_DIV_VALUE) {
+ reg_val = __ccu_read(ccu, div->u.s.offset);
+ reg_div = bitfield_extract(reg_val, div->u.s.shift,
+ div->u.s.width);
+ div->u.s.scaled_div = scaled_div_value(div, reg_div);
return 0;
}
/* Convert the scaled divisor to the value we need to record */
- reg_div = divider(div, div->scaled_div);
+ reg_div = divider(div, div->u.s.scaled_div);
/* Clock needs to be enabled before changing the rate */
enabled = __is_clk_gate_enabled(ccu, gate);
@@ -452,9 +635,10 @@ static int __div_commit(struct ccu_data *ccu, struct bcm_clk_gate *gate,
}
/* Replace the divider value and record the result */
- reg_val = __ccu_read(ccu, div->offset);
- reg_val = bitfield_replace(reg_val, div->shift, div->width, reg_div);
- __ccu_write(ccu, div->offset, reg_val);
+ reg_val = __ccu_read(ccu, div->u.s.offset);
+ reg_val = bitfield_replace(reg_val, div->u.s.shift, div->u.s.width,
+ reg_div);
+ __ccu_write(ccu, div->u.s.offset, reg_val);
/* If the trigger fails we still want to disable the gate */
if (!__clk_trigger(ccu, trig))
@@ -490,11 +674,11 @@ static int divider_write(struct ccu_data *ccu, struct bcm_clk_gate *gate,
BUG_ON(divider_is_fixed(div));
- previous = div->scaled_div;
+ previous = div->u.s.scaled_div;
if (previous == scaled_div)
return 0; /* No change */
- div->scaled_div = scaled_div;
+ div->u.s.scaled_div = scaled_div;
flags = ccu_lock(ccu);
__ccu_write_enable(ccu);
@@ -505,7 +689,7 @@ static int divider_write(struct ccu_data *ccu, struct bcm_clk_gate *gate,
ccu_unlock(ccu, flags);
if (ret)
- div->scaled_div = previous; /* Revert the change */
+ div->u.s.scaled_div = previous; /* Revert the change */
return ret;
@@ -802,23 +986,23 @@ static int selector_write(struct ccu_data *ccu, struct bcm_clk_gate *gate,
static int kona_peri_clk_enable(struct clk_hw *hw)
{
struct kona_clk *bcm_clk = to_kona_clk(hw);
- struct bcm_clk_gate *gate = &bcm_clk->peri->gate;
+ struct bcm_clk_gate *gate = &bcm_clk->u.peri->gate;
- return clk_gate(bcm_clk->ccu, bcm_clk->name, gate, true);
+ return clk_gate(bcm_clk->ccu, bcm_clk->init_data.name, gate, true);
}
static void kona_peri_clk_disable(struct clk_hw *hw)
{
struct kona_clk *bcm_clk = to_kona_clk(hw);
- struct bcm_clk_gate *gate = &bcm_clk->peri->gate;
+ struct bcm_clk_gate *gate = &bcm_clk->u.peri->gate;
- (void)clk_gate(bcm_clk->ccu, bcm_clk->name, gate, false);
+ (void)clk_gate(bcm_clk->ccu, bcm_clk->init_data.name, gate, false);
}
static int kona_peri_clk_is_enabled(struct clk_hw *hw)
{
struct kona_clk *bcm_clk = to_kona_clk(hw);
- struct bcm_clk_gate *gate = &bcm_clk->peri->gate;
+ struct bcm_clk_gate *gate = &bcm_clk->u.peri->gate;
return is_clk_gate_enabled(bcm_clk->ccu, gate) ? 1 : 0;
}
@@ -827,7 +1011,7 @@ static unsigned long kona_peri_clk_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct kona_clk *bcm_clk = to_kona_clk(hw);
- struct peri_clk_data *data = bcm_clk->peri;
+ struct peri_clk_data *data = bcm_clk->u.peri;
return clk_recalc_rate(bcm_clk->ccu, &data->div, &data->pre_div,
parent_rate);
@@ -837,20 +1021,72 @@ static long kona_peri_clk_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *parent_rate)
{
struct kona_clk *bcm_clk = to_kona_clk(hw);
- struct bcm_clk_div *div = &bcm_clk->peri->div;
+ struct bcm_clk_div *div = &bcm_clk->u.peri->div;
if (!divider_exists(div))
return __clk_get_rate(hw->clk);
/* Quietly avoid a zero rate */
- return round_rate(bcm_clk->ccu, div, &bcm_clk->peri->pre_div,
+ return round_rate(bcm_clk->ccu, div, &bcm_clk->u.peri->pre_div,
rate ? rate : 1, *parent_rate, NULL);
}
+static long kona_peri_clk_determine_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *best_parent_rate, struct clk **best_parent)
+{
+ struct kona_clk *bcm_clk = to_kona_clk(hw);
+ struct clk *clk = hw->clk;
+ struct clk *current_parent;
+ unsigned long parent_rate;
+ unsigned long best_delta;
+ unsigned long best_rate;
+ u32 parent_count;
+ u32 which;
+
+ /*
+ * If there is no other parent to choose, use the current one.
+ * Note: We don't honor (or use) CLK_SET_RATE_NO_REPARENT.
+ */
+ WARN_ON_ONCE(bcm_clk->init_data.flags & CLK_SET_RATE_NO_REPARENT);
+ parent_count = (u32)bcm_clk->init_data.num_parents;
+ if (parent_count < 2)
+ return kona_peri_clk_round_rate(hw, rate, best_parent_rate);
+
+ /* Unless we can do better, stick with current parent */
+ current_parent = clk_get_parent(clk);
+ parent_rate = __clk_get_rate(current_parent);
+ best_rate = kona_peri_clk_round_rate(hw, rate, &parent_rate);
+ best_delta = abs(best_rate - rate);
+
+ /* Check whether any other parent clock can produce a better result */
+ for (which = 0; which < parent_count; which++) {
+ struct clk *parent = clk_get_parent_by_index(clk, which);
+ unsigned long delta;
+ unsigned long other_rate;
+
+ BUG_ON(!parent);
+ if (parent == current_parent)
+ continue;
+
+ /* We don't support CLK_SET_RATE_PARENT */
+ parent_rate = __clk_get_rate(parent);
+ other_rate = kona_peri_clk_round_rate(hw, rate, &parent_rate);
+ delta = abs(other_rate - rate);
+ if (delta < best_delta) {
+ best_delta = delta;
+ best_rate = other_rate;
+ *best_parent = parent;
+ *best_parent_rate = parent_rate;
+ }
+ }
+
+ return best_rate;
+}
+
static int kona_peri_clk_set_parent(struct clk_hw *hw, u8 index)
{
struct kona_clk *bcm_clk = to_kona_clk(hw);
- struct peri_clk_data *data = bcm_clk->peri;
+ struct peri_clk_data *data = bcm_clk->u.peri;
struct bcm_clk_sel *sel = &data->sel;
struct bcm_clk_trig *trig;
int ret;
@@ -870,12 +1106,13 @@ static int kona_peri_clk_set_parent(struct clk_hw *hw, u8 index)
ret = selector_write(bcm_clk->ccu, &data->gate, sel, trig, index);
if (ret == -ENXIO) {
- pr_err("%s: gating failure for %s\n", __func__, bcm_clk->name);
+ pr_err("%s: gating failure for %s\n", __func__,
+ bcm_clk->init_data.name);
ret = -EIO; /* Don't proliferate weird errors */
} else if (ret == -EIO) {
pr_err("%s: %strigger failed for %s\n", __func__,
trig == &data->pre_trig ? "pre-" : "",
- bcm_clk->name);
+ bcm_clk->init_data.name);
}
return ret;
@@ -884,7 +1121,7 @@ static int kona_peri_clk_set_parent(struct clk_hw *hw, u8 index)
static u8 kona_peri_clk_get_parent(struct clk_hw *hw)
{
struct kona_clk *bcm_clk = to_kona_clk(hw);
- struct peri_clk_data *data = bcm_clk->peri;
+ struct peri_clk_data *data = bcm_clk->u.peri;
u8 index;
index = selector_read_index(bcm_clk->ccu, &data->sel);
@@ -897,7 +1134,7 @@ static int kona_peri_clk_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
struct kona_clk *bcm_clk = to_kona_clk(hw);
- struct peri_clk_data *data = bcm_clk->peri;
+ struct peri_clk_data *data = bcm_clk->u.peri;
struct bcm_clk_div *div = &data->div;
u64 scaled_div = 0;
int ret;
@@ -934,10 +1171,12 @@ static int kona_peri_clk_set_rate(struct clk_hw *hw, unsigned long rate,
ret = divider_write(bcm_clk->ccu, &data->gate, &data->div,
&data->trig, scaled_div);
if (ret == -ENXIO) {
- pr_err("%s: gating failure for %s\n", __func__, bcm_clk->name);
+ pr_err("%s: gating failure for %s\n", __func__,
+ bcm_clk->init_data.name);
ret = -EIO; /* Don't proliferate weird errors */
} else if (ret == -EIO) {
- pr_err("%s: trigger failed for %s\n", __func__, bcm_clk->name);
+ pr_err("%s: trigger failed for %s\n", __func__,
+ bcm_clk->init_data.name);
}
return ret;
@@ -948,7 +1187,7 @@ struct clk_ops kona_peri_clk_ops = {
.disable = kona_peri_clk_disable,
.is_enabled = kona_peri_clk_is_enabled,
.recalc_rate = kona_peri_clk_recalc_rate,
- .round_rate = kona_peri_clk_round_rate,
+ .determine_rate = kona_peri_clk_determine_rate,
.set_parent = kona_peri_clk_set_parent,
.get_parent = kona_peri_clk_get_parent,
.set_rate = kona_peri_clk_set_rate,
@@ -958,16 +1197,25 @@ struct clk_ops kona_peri_clk_ops = {
static bool __peri_clk_init(struct kona_clk *bcm_clk)
{
struct ccu_data *ccu = bcm_clk->ccu;
- struct peri_clk_data *peri = bcm_clk->peri;
- const char *name = bcm_clk->name;
+ struct peri_clk_data *peri = bcm_clk->u.peri;
+ const char *name = bcm_clk->init_data.name;
struct bcm_clk_trig *trig;
BUG_ON(bcm_clk->type != bcm_clk_peri);
+ if (!policy_init(ccu, &peri->policy)) {
+ pr_err("%s: error initializing policy for %s\n",
+ __func__, name);
+ return false;
+ }
if (!gate_init(ccu, &peri->gate)) {
pr_err("%s: error initializing gate for %s\n", __func__, name);
return false;
}
+ if (!hyst_init(ccu, &peri->hyst)) {
+ pr_err("%s: error initializing hyst for %s\n", __func__, name);
+ return false;
+ }
if (!div_init(ccu, &peri->gate, &peri->div, &peri->trig)) {
pr_err("%s: error initializing divider for %s\n", __func__,
name);
@@ -1012,13 +1260,13 @@ bool __init kona_ccu_init(struct ccu_data *ccu)
{
unsigned long flags;
unsigned int which;
- struct clk **clks = ccu->data.clks;
+ struct clk **clks = ccu->clk_data.clks;
bool success = true;
flags = ccu_lock(ccu);
__ccu_write_enable(ccu);
- for (which = 0; which < ccu->data.clk_num; which++) {
+ for (which = 0; which < ccu->clk_data.clk_num; which++) {
struct kona_clk *bcm_clk;
if (!clks[which])
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-03-30 04:26:50 +0000