Re: [PATCH v3 2/5] clk: Ingenic: Adjust cgu code to make it compatible with X1830.

From: Paul Cercueil
Date: Sat Dec 14 2019 - 13:09:58 EST

Hi Zhou,

The patch looks good but it should be merged with [3/5]. Because right now it is not atomic, if you only have the first two patches applied the kernel won't compile.

-Paul


Le sam., dÃc. 14, 2019 at 23:33, åçæ (Zhou Yanjie) <zhouyanjie@xxxxxxxxxxxxxx> a Ãcrit :
The PLL of X1830 Soc from Ingenic has been greatly changed,
the bypass control is placed in another register, so now two
registers may needed to control the PLL. To this end, the
original "reg" was changed to "pll_reg", and a new "bypass_reg"
was introduced. In addition, when calculating rate, the PLL of
X1830 introduced an extra 2x multiplier, so a new "rate_multiplier"
was introduced.

Signed-off-by: åçæ (Zhou Yanjie) <zhouyanjie@xxxxxxxxxxxxxx>
---

Notes:
v1->v2:
1.Use two fields (pll_reg & bypass_reg) instead of the 2-values
array (reg[2]).
2.Remove the "pll_info->version" and add a "pll_info->rate_multiplier".
3.Fix the coding style and add more detailed commit message.
4.Change my Signed-off-by from "Zhou Yanjie <zhouyanjie@xxxxxxxx>"
to "åçæ (Zhou Yanjie) <zhouyanjie@xxxxxxxxxxxxxx>" because
the old mailbox is in an unstable state.

v2->v3:
Adjust order from [1/5] in v2 to [2/5] in v3.

drivers/clk/ingenic/cgu.c | 30 +++++++++++++++++++-----------
drivers/clk/ingenic/cgu.h | 8 ++++++--
2 files changed, 25 insertions(+), 13 deletions(-)

diff --git a/drivers/clk/ingenic/cgu.c b/drivers/clk/ingenic/cgu.c
index 8bd3998..3c95451 100644
--- a/drivers/clk/ingenic/cgu.c
+++ b/drivers/clk/ingenic/cgu.c
@@ -82,7 +82,7 @@ ingenic_pll_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
BUG_ON(clk_info->type != CGU_CLK_PLL);
pll_info = &clk_info->pll;

- ctl = readl(cgu->base + pll_info->reg);
+ ctl = readl(cgu->base + pll_info->pll_reg);

m = (ctl >> pll_info->m_shift) & GENMASK(pll_info->m_bits - 1, 0);
m += pll_info->m_offset;
@@ -90,6 +90,9 @@ ingenic_pll_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
n += pll_info->n_offset;
od_enc = ctl >> pll_info->od_shift;
od_enc &= GENMASK(pll_info->od_bits - 1, 0);
+
+ ctl = readl(cgu->base + pll_info->bypass_reg);
+
bypass = !pll_info->no_bypass_bit &&
!!(ctl & BIT(pll_info->bypass_bit));

@@ -103,7 +106,7 @@ ingenic_pll_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
BUG_ON(od == pll_info->od_max);
od++;

- return div_u64((u64)parent_rate * m, n * od);
+ return div_u64((u64)parent_rate * m * pll_info->rate_multiplier, n * od);
}

static unsigned long
@@ -136,7 +139,7 @@ ingenic_pll_calc(const struct ingenic_cgu_clk_info *clk_info,
if (pod)
*pod = od;

- return div_u64((u64)parent_rate * m, n * od);
+ return div_u64((u64)parent_rate * m * pll_info->rate_multiplier, n * od);
}

static inline const struct ingenic_cgu_clk_info *to_clk_info(
@@ -180,7 +183,7 @@ ingenic_pll_set_rate(struct clk_hw *hw, unsigned long req_rate,
clk_info->name, req_rate, rate);

spin_lock_irqsave(&cgu->lock, flags);
- ctl = readl(cgu->base + pll_info->reg);
+ ctl = readl(cgu->base + pll_info->pll_reg);

ctl &= ~(GENMASK(pll_info->m_bits - 1, 0) << pll_info->m_shift);
ctl |= (m - pll_info->m_offset) << pll_info->m_shift;
@@ -191,7 +194,7 @@ ingenic_pll_set_rate(struct clk_hw *hw, unsigned long req_rate,
ctl &= ~(GENMASK(pll_info->od_bits - 1, 0) << pll_info->od_shift);
ctl |= pll_info->od_encoding[od - 1] << pll_info->od_shift;

- writel(ctl, cgu->base + pll_info->reg);
+ writel(ctl, cgu->base + pll_info->pll_reg);
spin_unlock_irqrestore(&cgu->lock, flags);

return 0;
@@ -209,16 +212,21 @@ static int ingenic_pll_enable(struct clk_hw *hw)
u32 ctl;

spin_lock_irqsave(&cgu->lock, flags);
- ctl = readl(cgu->base + pll_info->reg);
+ ctl = readl(cgu->base + pll_info->bypass_reg);

ctl &= ~BIT(pll_info->bypass_bit);
+
+ writel(ctl, cgu->base + pll_info->bypass_reg);
+
+ ctl = readl(cgu->base + pll_info->pll_reg);
+
ctl |= BIT(pll_info->enable_bit);

- writel(ctl, cgu->base + pll_info->reg);
+ writel(ctl, cgu->base + pll_info->pll_reg);

/* wait for the PLL to stabilise */
for (i = 0; i < timeout; i++) {
- ctl = readl(cgu->base + pll_info->reg);
+ ctl = readl(cgu->base + pll_info->pll_reg);
if (ctl & BIT(pll_info->stable_bit))
break;
mdelay(1);
@@ -242,11 +250,11 @@ static void ingenic_pll_disable(struct clk_hw *hw)
u32 ctl;

spin_lock_irqsave(&cgu->lock, flags);
- ctl = readl(cgu->base + pll_info->reg);
+ ctl = readl(cgu->base + pll_info->pll_reg);

ctl &= ~BIT(pll_info->enable_bit);

- writel(ctl, cgu->base + pll_info->reg);
+ writel(ctl, cgu->base + pll_info->pll_reg);
spin_unlock_irqrestore(&cgu->lock, flags);
}

@@ -258,7 +266,7 @@ static int ingenic_pll_is_enabled(struct clk_hw *hw)
const struct ingenic_cgu_pll_info *pll_info = &clk_info->pll;
u32 ctl;

- ctl = readl(cgu->base + pll_info->reg);
+ ctl = readl(cgu->base + pll_info->pll_reg);

return !!(ctl & BIT(pll_info->enable_bit));
}
diff --git a/drivers/clk/ingenic/cgu.h b/drivers/clk/ingenic/cgu.h
index 0dc8004..f7b6908 100644
--- a/drivers/clk/ingenic/cgu.h
+++ b/drivers/clk/ingenic/cgu.h
@@ -16,7 +16,9 @@

/**
* struct ingenic_cgu_pll_info - information about a PLL
- * @reg: the offset of the PLL's control register within the CGU
+ * @pll_reg: the offset of the PLL's control register within the CGU
+ * @bypass_reg: the offset of the bypass control register within the CGU
+ * @rate_multiplier: the multiplier needed by pll rate calculation
* @m_shift: the number of bits to shift the multiplier value by (ie. the
* index of the lowest bit of the multiplier value in the PLL's
* control register)
@@ -43,7 +45,9 @@
* @no_bypass_bit: if set, the PLL has no bypass functionality
*/
struct ingenic_cgu_pll_info {
- unsigned reg;
+ unsigned pll_reg;
+ unsigned bypass_reg;
+ unsigned rate_multiplier;
const s8 *od_encoding;
u8 m_shift, m_bits, m_offset;
u8 n_shift, n_bits, n_offset;
--
2.7.4