[PATCH v5 06/11] clk: at91: clk-sam9x60-pll: allow runtime changes for pll

From: Claudiu Beznea
Date: Thu Nov 19 2020 - 09:39:32 EST

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Allow runtime frequency changes for PLLs registered with proper flags.
This is necessary for CPU PLL on SAMA7G5 which is used by DVFS.

Signed-off-by: Claudiu Beznea <claudiu.beznea@xxxxxxxxxxxxx>
---
drivers/clk/at91/clk-sam9x60-pll.c | 145 ++++++++++++++++++++++++++++++++-----
drivers/clk/at91/pmc.h | 4 +-
drivers/clk/at91/sam9x60.c | 22 +++++-
drivers/clk/at91/sama7g5.c | 67 ++++++++++++-----
4 files changed, 197 insertions(+), 41 deletions(-)

diff --git a/drivers/clk/at91/clk-sam9x60-pll.c b/drivers/clk/at91/clk-sam9x60-pll.c
index 78f458a7b2ef..34e3ab13741a 100644
--- a/drivers/clk/at91/clk-sam9x60-pll.c
+++ b/drivers/clk/at91/clk-sam9x60-pll.c
@@ -229,6 +229,57 @@ static int sam9x60_frac_pll_set_rate(struct clk_hw *hw, unsigned long rate,
return sam9x60_frac_pll_compute_mul_frac(core, rate, parent_rate, true);
}

+static int sam9x60_frac_pll_set_rate_chg(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct sam9x60_pll_core *core = to_sam9x60_pll_core(hw);
+ struct sam9x60_frac *frac = to_sam9x60_frac(core);
+ struct regmap *regmap = core->regmap;
+ unsigned long irqflags;
+ unsigned int val, cfrac, cmul;
+ long ret;
+
+ ret = sam9x60_frac_pll_compute_mul_frac(core, rate, parent_rate, true);
+ if (ret <= 0)
+ return ret;
+
+ spin_lock_irqsave(core->lock, irqflags);
+
+ regmap_update_bits(regmap, AT91_PMC_PLL_UPDT, AT91_PMC_PLL_UPDT_ID_MSK,
+ core->id);
+ regmap_read(regmap, AT91_PMC_PLL_CTRL1, &val);
+ cmul = (val & core->layout->mul_mask) >> core->layout->mul_shift;
+ cfrac = (val & core->layout->frac_mask) >> core->layout->frac_shift;
+
+ if (cmul == frac->mul && cfrac == frac->frac)
+ goto unlock;
+
+ regmap_write(regmap, AT91_PMC_PLL_CTRL1,
+ (frac->mul << core->layout->mul_shift) |
+ (frac->frac << core->layout->frac_shift));
+
+ regmap_update_bits(regmap, AT91_PMC_PLL_UPDT,
+ AT91_PMC_PLL_UPDT_UPDATE | AT91_PMC_PLL_UPDT_ID_MSK,
+ AT91_PMC_PLL_UPDT_UPDATE | core->id);
+
+ regmap_update_bits(regmap, AT91_PMC_PLL_CTRL0,
+ AT91_PMC_PLL_CTRL0_ENLOCK | AT91_PMC_PLL_CTRL0_ENPLL,
+ AT91_PMC_PLL_CTRL0_ENLOCK |
+ AT91_PMC_PLL_CTRL0_ENPLL);
+
+ regmap_update_bits(regmap, AT91_PMC_PLL_UPDT,
+ AT91_PMC_PLL_UPDT_UPDATE | AT91_PMC_PLL_UPDT_ID_MSK,
+ AT91_PMC_PLL_UPDT_UPDATE | core->id);
+
+ while (!sam9x60_pll_ready(regmap, core->id))
+ cpu_relax();
+
+unlock:
+ spin_unlock_irqrestore(core->lock, irqflags);
+
+ return ret;
+}
+
static const struct clk_ops sam9x60_frac_pll_ops = {
.prepare = sam9x60_frac_pll_prepare,
.unprepare = sam9x60_frac_pll_unprepare,
@@ -238,6 +289,15 @@ static const struct clk_ops sam9x60_frac_pll_ops = {
.set_rate = sam9x60_frac_pll_set_rate,
};

+static const struct clk_ops sam9x60_frac_pll_ops_chg = {
+ .prepare = sam9x60_frac_pll_prepare,
+ .unprepare = sam9x60_frac_pll_unprepare,
+ .is_prepared = sam9x60_frac_pll_is_prepared,
+ .recalc_rate = sam9x60_frac_pll_recalc_rate,
+ .round_rate = sam9x60_frac_pll_round_rate,
+ .set_rate = sam9x60_frac_pll_set_rate_chg,
+};
+
static int sam9x60_div_pll_prepare(struct clk_hw *hw)
{
struct sam9x60_pll_core *core = to_sam9x60_pll_core(hw);
@@ -384,6 +444,44 @@ static int sam9x60_div_pll_set_rate(struct clk_hw *hw, unsigned long rate,
return 0;
}

+static int sam9x60_div_pll_set_rate_chg(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct sam9x60_pll_core *core = to_sam9x60_pll_core(hw);
+ struct sam9x60_div *div = to_sam9x60_div(core);
+ struct regmap *regmap = core->regmap;
+ unsigned long irqflags;
+ unsigned int val, cdiv;
+
+ div->div = DIV_ROUND_CLOSEST(parent_rate, rate) - 1;
+
+ spin_lock_irqsave(core->lock, irqflags);
+ regmap_update_bits(regmap, AT91_PMC_PLL_UPDT, AT91_PMC_PLL_UPDT_ID_MSK,
+ core->id);
+ regmap_read(regmap, AT91_PMC_PLL_CTRL0, &val);
+ cdiv = (val & core->layout->div_mask) >> core->layout->div_shift;
+
+ /* Stop if nothing changed. */
+ if (cdiv == div->div)
+ goto unlock;
+
+ regmap_update_bits(regmap, AT91_PMC_PLL_CTRL0,
+ core->layout->div_mask,
+ (div->div << core->layout->div_shift));
+
+ regmap_update_bits(regmap, AT91_PMC_PLL_UPDT,
+ AT91_PMC_PLL_UPDT_UPDATE | AT91_PMC_PLL_UPDT_ID_MSK,
+ AT91_PMC_PLL_UPDT_UPDATE | core->id);
+
+ while (!sam9x60_pll_ready(regmap, core->id))
+ cpu_relax();
+
+unlock:
+ spin_unlock_irqrestore(core->lock, irqflags);
+
+ return 0;
+}
+
static const struct clk_ops sam9x60_div_pll_ops = {
.prepare = sam9x60_div_pll_prepare,
.unprepare = sam9x60_div_pll_unprepare,
@@ -393,17 +491,26 @@ static const struct clk_ops sam9x60_div_pll_ops = {
.set_rate = sam9x60_div_pll_set_rate,
};

+static const struct clk_ops sam9x60_div_pll_ops_chg = {
+ .prepare = sam9x60_div_pll_prepare,
+ .unprepare = sam9x60_div_pll_unprepare,
+ .is_prepared = sam9x60_div_pll_is_prepared,
+ .recalc_rate = sam9x60_div_pll_recalc_rate,
+ .round_rate = sam9x60_div_pll_round_rate,
+ .set_rate = sam9x60_div_pll_set_rate_chg,
+};
+
struct clk_hw * __init
sam9x60_clk_register_frac_pll(struct regmap *regmap, spinlock_t *lock,
const char *name, const char *parent_name,
struct clk_hw *parent_hw, u8 id,
const struct clk_pll_characteristics *characteristics,
- const struct clk_pll_layout *layout, bool critical)
+ const struct clk_pll_layout *layout, u32 flags)
{
struct sam9x60_frac *frac;
struct clk_hw *hw;
struct clk_init_data init;
- unsigned long parent_rate, flags;
+ unsigned long parent_rate, irqflags;
unsigned int val;
int ret;

@@ -417,10 +524,12 @@ sam9x60_clk_register_frac_pll(struct regmap *regmap, spinlock_t *lock,
init.name = name;
init.parent_names = &parent_name;
init.num_parents = 1;
- init.ops = &sam9x60_frac_pll_ops;
- init.flags = CLK_SET_RATE_GATE;
- if (critical)
- init.flags |= CLK_IS_CRITICAL;
+ if (flags & CLK_SET_RATE_GATE)
+ init.ops = &sam9x60_frac_pll_ops;
+ else
+ init.ops = &sam9x60_frac_pll_ops_chg;
+
+ init.flags = flags;

frac->core.id = id;
frac->core.hw.init = &init;
@@ -429,7 +538,7 @@ sam9x60_clk_register_frac_pll(struct regmap *regmap, spinlock_t *lock,
frac->core.regmap = regmap;
frac->core.lock = lock;

- spin_lock_irqsave(frac->core.lock, flags);
+ spin_lock_irqsave(frac->core.lock, irqflags);
if (sam9x60_pll_ready(regmap, id)) {
regmap_update_bits(regmap, AT91_PMC_PLL_UPDT,
AT91_PMC_PLL_UPDT_ID_MSK, id);
@@ -457,7 +566,7 @@ sam9x60_clk_register_frac_pll(struct regmap *regmap, spinlock_t *lock,
goto free;
}
}
- spin_unlock_irqrestore(frac->core.lock, flags);
+ spin_unlock_irqrestore(frac->core.lock, irqflags);

hw = &frac->core.hw;
ret = clk_hw_register(NULL, hw);
@@ -469,7 +578,7 @@ sam9x60_clk_register_frac_pll(struct regmap *regmap, spinlock_t *lock,
return hw;

free:
- spin_unlock_irqrestore(frac->core.lock, flags);
+ spin_unlock_irqrestore(frac->core.lock, irqflags);
kfree(frac);
return hw;
}
@@ -478,12 +587,12 @@ struct clk_hw * __init
sam9x60_clk_register_div_pll(struct regmap *regmap, spinlock_t *lock,
const char *name, const char *parent_name, u8 id,
const struct clk_pll_characteristics *characteristics,
- const struct clk_pll_layout *layout, bool critical)
+ const struct clk_pll_layout *layout, u32 flags)
{
struct sam9x60_div *div;
struct clk_hw *hw;
struct clk_init_data init;
- unsigned long flags;
+ unsigned long irqflags;
unsigned int val;
int ret;

@@ -497,11 +606,11 @@ sam9x60_clk_register_div_pll(struct regmap *regmap, spinlock_t *lock,
init.name = name;
init.parent_names = &parent_name;
init.num_parents = 1;
- init.ops = &sam9x60_div_pll_ops;
- init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE |
- CLK_SET_RATE_PARENT;
- if (critical)
- init.flags |= CLK_IS_CRITICAL;
+ if (flags & CLK_SET_RATE_GATE)
+ init.ops = &sam9x60_div_pll_ops;
+ else
+ init.ops = &sam9x60_div_pll_ops_chg;
+ init.flags = flags;

div->core.id = id;
div->core.hw.init = &init;
@@ -510,14 +619,14 @@ sam9x60_clk_register_div_pll(struct regmap *regmap, spinlock_t *lock,
div->core.regmap = regmap;
div->core.lock = lock;

- spin_lock_irqsave(div->core.lock, flags);
+ spin_lock_irqsave(div->core.lock, irqflags);

regmap_update_bits(regmap, AT91_PMC_PLL_UPDT,
AT91_PMC_PLL_UPDT_ID_MSK, id);
regmap_read(regmap, AT91_PMC_PLL_CTRL0, &val);
div->div = FIELD_GET(PMC_PLL_CTRL0_DIV_MSK, val);

- spin_unlock_irqrestore(div->core.lock, flags);
+ spin_unlock_irqrestore(div->core.lock, irqflags);

hw = &div->core.hw;
ret = clk_hw_register(NULL, hw);
diff --git a/drivers/clk/at91/pmc.h b/drivers/clk/at91/pmc.h
index 0a9364bde339..bedcd85ad750 100644
--- a/drivers/clk/at91/pmc.h
+++ b/drivers/clk/at91/pmc.h
@@ -190,14 +190,14 @@ struct clk_hw * __init
sam9x60_clk_register_div_pll(struct regmap *regmap, spinlock_t *lock,
const char *name, const char *parent_name, u8 id,
const struct clk_pll_characteristics *characteristics,
- const struct clk_pll_layout *layout, bool critical);
+ const struct clk_pll_layout *layout, u32 flags);

struct clk_hw * __init
sam9x60_clk_register_frac_pll(struct regmap *regmap, spinlock_t *lock,
const char *name, const char *parent_name,
struct clk_hw *parent_hw, u8 id,
const struct clk_pll_characteristics *characteristics,
- const struct clk_pll_layout *layout, bool critical);
+ const struct clk_pll_layout *layout, u32 flags);

struct clk_hw * __init
at91_clk_register_programmable(struct regmap *regmap, const char *name,
diff --git a/drivers/clk/at91/sam9x60.c b/drivers/clk/at91/sam9x60.c
index 3c4c95603595..dd62bb2880cf 100644
--- a/drivers/clk/at91/sam9x60.c
+++ b/drivers/clk/at91/sam9x60.c
@@ -228,13 +228,24 @@ static void __init sam9x60_pmc_setup(struct device_node *np)
hw = sam9x60_clk_register_frac_pll(regmap, &pmc_pll_lock, "pllack_fracck",
"mainck", sam9x60_pmc->chws[PMC_MAIN],
0, &plla_characteristics,
- &pll_frac_layout, true);
+ &pll_frac_layout,
+ /*
+ * This feeds pllack_divck which
+ * feeds CPU. It should not be
+ * disabled.
+ */
+ CLK_IS_CRITICAL | CLK_SET_RATE_GATE);
if (IS_ERR(hw))
goto err_free;

hw = sam9x60_clk_register_div_pll(regmap, &pmc_pll_lock, "pllack_divck",
"pllack_fracck", 0, &plla_characteristics,
- &pll_div_layout, true);
+ &pll_div_layout,
+ /*
+ * This feeds CPU. It should not
+ * be disabled.
+ */
+ CLK_IS_CRITICAL | CLK_SET_RATE_GATE);
if (IS_ERR(hw))
goto err_free;

@@ -243,13 +254,16 @@ static void __init sam9x60_pmc_setup(struct device_node *np)
hw = sam9x60_clk_register_frac_pll(regmap, &pmc_pll_lock, "upllck_fracck",
"main_osc", main_osc_hw, 1,
&upll_characteristics,
- &pll_frac_layout, false);
+ &pll_frac_layout, CLK_SET_RATE_GATE);
if (IS_ERR(hw))
goto err_free;

hw = sam9x60_clk_register_div_pll(regmap, &pmc_pll_lock, "upllck_divck",
"upllck_fracck", 1, &upll_characteristics,
- &pll_div_layout, false);
+ &pll_div_layout,
+ CLK_SET_RATE_GATE |
+ CLK_SET_PARENT_GATE |
+ CLK_SET_RATE_PARENT);
if (IS_ERR(hw))
goto err_free;

diff --git a/drivers/clk/at91/sama7g5.c b/drivers/clk/at91/sama7g5.c
index d685e22b2014..d7c2b731ad20 100644
--- a/drivers/clk/at91/sama7g5.c
+++ b/drivers/clk/at91/sama7g5.c
@@ -95,15 +95,15 @@ static const struct clk_pll_layout pll_layout_divio = {
* @p: clock parent
* @l: clock layout
* @t: clock type
- * @f: true if clock is critical and cannot be disabled
+ * @f: clock flags
* @eid: export index in sama7g5->chws[] array
*/
static const struct {
const char *n;
const char *p;
const struct clk_pll_layout *l;
+ unsigned long f;
u8 t;
- u8 c;
u8 eid;
} sama7g5_plls[][PLL_ID_MAX] = {
[PLL_ID_CPU] = {
@@ -111,13 +111,18 @@ static const struct {
.p = "mainck",
.l = &pll_layout_frac,
.t = PLL_TYPE_FRAC,
- .c = 1, },
+ /*
+ * This feeds cpupll_divpmcck which feeds CPU. It should
+ * not be disabled.
+ */
+ .f = CLK_IS_CRITICAL, },

{ .n = "cpupll_divpmcck",
.p = "cpupll_fracck",
.l = &pll_layout_divpmc,
.t = PLL_TYPE_DIV,
- .c = 1,
+ /* This feeds CPU. It should not be disabled. */
+ .f = CLK_IS_CRITICAL | CLK_SET_RATE_PARENT,
.eid = PMC_CPUPLL, },
},

@@ -126,13 +131,22 @@ static const struct {
.p = "mainck",
.l = &pll_layout_frac,
.t = PLL_TYPE_FRAC,
- .c = 1, },
+ /*
+ * This feeds syspll_divpmcck which may feed critial parts
+ * of the systems like timers. Therefore it should not be
+ * disabled.
+ */
+ .f = CLK_IS_CRITICAL | CLK_SET_RATE_GATE, },

{ .n = "syspll_divpmcck",
.p = "syspll_fracck",
.l = &pll_layout_divpmc,
.t = PLL_TYPE_DIV,
- .c = 1,
+ /*
+ * This may feed critial parts of the systems like timers.
+ * Therefore it should not be disabled.
+ */
+ .f = CLK_IS_CRITICAL | CLK_SET_RATE_GATE,
.eid = PMC_SYSPLL, },
},

@@ -141,55 +155,71 @@ static const struct {
.p = "mainck",
.l = &pll_layout_frac,
.t = PLL_TYPE_FRAC,
- .c = 1, },
+ /*
+ * This feeds ddrpll_divpmcck which feeds DDR. It should not
+ * be disabled.
+ */
+ .f = CLK_IS_CRITICAL | CLK_SET_RATE_GATE, },

{ .n = "ddrpll_divpmcck",
.p = "ddrpll_fracck",
.l = &pll_layout_divpmc,
.t = PLL_TYPE_DIV,
- .c = 1, },
+ /* This feeds DDR. It should not be disabled. */
+ .f = CLK_IS_CRITICAL | CLK_SET_RATE_GATE, },
},

[PLL_ID_IMG] = {
{ .n = "imgpll_fracck",
.p = "mainck",
.l = &pll_layout_frac,
- .t = PLL_TYPE_FRAC, },
+ .t = PLL_TYPE_FRAC,
+ .f = CLK_SET_RATE_GATE, },

{ .n = "imgpll_divpmcck",
.p = "imgpll_fracck",
.l = &pll_layout_divpmc,
- .t = PLL_TYPE_DIV, },
+ .t = PLL_TYPE_DIV,
+ .f = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE |
+ CLK_SET_RATE_PARENT, },
},

[PLL_ID_BAUD] = {
{ .n = "baudpll_fracck",
.p = "mainck",
.l = &pll_layout_frac,
- .t = PLL_TYPE_FRAC, },
+ .t = PLL_TYPE_FRAC,
+ .f = CLK_SET_RATE_GATE, },

{ .n = "baudpll_divpmcck",
.p = "baudpll_fracck",
.l = &pll_layout_divpmc,
- .t = PLL_TYPE_DIV, },
+ .t = PLL_TYPE_DIV,
+ .f = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE |
+ CLK_SET_RATE_PARENT, },
},

[PLL_ID_AUDIO] = {
{ .n = "audiopll_fracck",
.p = "main_xtal",
.l = &pll_layout_frac,
- .t = PLL_TYPE_FRAC, },
+ .t = PLL_TYPE_FRAC,
+ .f = CLK_SET_RATE_GATE, },

{ .n = "audiopll_divpmcck",
.p = "audiopll_fracck",
.l = &pll_layout_divpmc,
.t = PLL_TYPE_DIV,
+ .f = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE |
+ CLK_SET_RATE_PARENT,
.eid = PMC_AUDIOPMCPLL, },

{ .n = "audiopll_diviock",
.p = "audiopll_fracck",
.l = &pll_layout_divio,
.t = PLL_TYPE_DIV,
+ .f = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE |
+ CLK_SET_RATE_PARENT,
.eid = PMC_AUDIOIOPLL, },
},

@@ -197,12 +227,15 @@ static const struct {
{ .n = "ethpll_fracck",
.p = "main_xtal",
.l = &pll_layout_frac,
- .t = PLL_TYPE_FRAC, },
+ .t = PLL_TYPE_FRAC,
+ .f = CLK_SET_RATE_GATE, },

{ .n = "ethpll_divpmcck",
.p = "ethpll_fracck",
.l = &pll_layout_divpmc,
- .t = PLL_TYPE_DIV, },
+ .t = PLL_TYPE_DIV,
+ .f = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE |
+ CLK_SET_RATE_PARENT, },
},
};

@@ -890,7 +923,7 @@ static void __init sama7g5_pmc_setup(struct device_node *np)
sama7g5_plls[i][j].p, parent_hw, i,
&pll_characteristics,
sama7g5_plls[i][j].l,
- sama7g5_plls[i][j].c);
+ sama7g5_plls[i][j].f);
break;

case PLL_TYPE_DIV:
@@ -899,7 +932,7 @@ static void __init sama7g5_pmc_setup(struct device_node *np)
sama7g5_plls[i][j].p, i,
&pll_characteristics,
sama7g5_plls[i][j].l,
- sama7g5_plls[i][j].c);
+ sama7g5_plls[i][j].f);
break;

default:
--
2.7.4

Next message: Claudiu Beznea: "[PATCH v5 07/11] clk: at91: sama7g5: remove mck0 from parent list of other clocks"
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