clk: at91: clk-sam9x60-pll: allow runtime changes for pll

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@microchip.com>
Link: https://lore.kernel.org/r/1605800597-16720-7-git-send-email-claudiu.beznea@microchip.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

diff --git a/drivers/clk/at91/clk-sam9x60-pll.c b/drivers/clk/at91/clk-sam9x60-pll.c
index 78f458a..34e3ab1 100644 (file)
--- 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 0a9364b..bedcd85 100644 (file)
--- 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 3c4c956..dd62bb2 100644 (file)
--- 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 d685e22..d7c2b73 100644 (file)
--- 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: