[PATCH v2 4/7] clk: meson: mpll: add init callback and regs

From: Jerome Brunet
Date: Mon May 13 2019 - 08:33:40 EST


Until now (gx and axg), the mpll setting on boot (whatever the
bootloader) was good enough to generate a clean fractional division.

It is not the case on the g12a. While moving away from the vendor u-boot,
it was noticed the fractional part of the divider was no longer applied.
Like on the pll, some magic settings need to applied on the mpll
register.

This change adds the ability to do that on the mpll driver.

Signed-off-by: Jerome Brunet <jbrunet@xxxxxxxxxxxx>
---
drivers/clk/meson/clk-mpll.c | 35 ++++++++++++++++++++++++-----------
drivers/clk/meson/clk-mpll.h | 2 ++
2 files changed, 26 insertions(+), 11 deletions(-)

diff --git a/drivers/clk/meson/clk-mpll.c b/drivers/clk/meson/clk-mpll.c
index d3f42e086431..2d39a8bc367c 100644
--- a/drivers/clk/meson/clk-mpll.c
+++ b/drivers/clk/meson/clk-mpll.c
@@ -115,8 +115,30 @@ static int mpll_set_rate(struct clk_hw *hw,
else
__acquire(mpll->lock);

- /* Enable and set the fractional part */
+ /* Set the fractional part */
meson_parm_write(clk->map, &mpll->sdm, sdm);
+
+ /* Set the integer divider part */
+ meson_parm_write(clk->map, &mpll->n2, n2);
+
+ if (mpll->lock)
+ spin_unlock_irqrestore(mpll->lock, flags);
+ else
+ __release(mpll->lock);
+
+ return 0;
+}
+
+static void mpll_init(struct clk_hw *hw)
+{
+ struct clk_regmap *clk = to_clk_regmap(hw);
+ struct meson_clk_mpll_data *mpll = meson_clk_mpll_data(clk);
+
+ if (mpll->init_count)
+ regmap_multi_reg_write(clk->map, mpll->init_regs,
+ mpll->init_count);
+
+ /* Enable the fractional part */
meson_parm_write(clk->map, &mpll->sdm_en, 1);

/* Set spread spectrum if possible */
@@ -126,19 +148,9 @@ static int mpll_set_rate(struct clk_hw *hw,
meson_parm_write(clk->map, &mpll->ssen, ss);
}

- /* Set the integer divider part */
- meson_parm_write(clk->map, &mpll->n2, n2);
-
/* Set the magic misc bit if required */
if (MESON_PARM_APPLICABLE(&mpll->misc))
meson_parm_write(clk->map, &mpll->misc, 1);
-
- if (mpll->lock)
- spin_unlock_irqrestore(mpll->lock, flags);
- else
- __release(mpll->lock);
-
- return 0;
}

const struct clk_ops meson_clk_mpll_ro_ops = {
@@ -151,6 +163,7 @@ const struct clk_ops meson_clk_mpll_ops = {
.recalc_rate = mpll_recalc_rate,
.round_rate = mpll_round_rate,
.set_rate = mpll_set_rate,
+ .init = mpll_init,
};
EXPORT_SYMBOL_GPL(meson_clk_mpll_ops);

diff --git a/drivers/clk/meson/clk-mpll.h b/drivers/clk/meson/clk-mpll.h
index 0f948430fed4..a991d568c43a 100644
--- a/drivers/clk/meson/clk-mpll.h
+++ b/drivers/clk/meson/clk-mpll.h
@@ -18,6 +18,8 @@ struct meson_clk_mpll_data {
struct parm n2;
struct parm ssen;
struct parm misc;
+ const struct reg_sequence *init_regs;
+ unsigned int init_count;
spinlock_t *lock;
u8 flags;
};
--
2.20.1