| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <20250827150811.82496-1-nicolas.ferre@microchip.com>
Date: Wed, 27 Aug 2025 17:08:10 +0200
From: <nicolas.ferre@...rochip.com>
To: ARM Maintainers <arm@...nel.org>, Alexandre Belloni
<alexandre.belloni@...tlin.com>, Ryan Wanner <ryan.wanner@...rochip.com>,
Varshini Rajendran <varshini.rajendran@...rochip.com>, Claudiu Beznea
<claudiu.beznea@...on.dev>
CC: Linux CLK <linux-clk@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
<linux-arm-kernel@...ts.infradead.org>, Nicolas Ferre
<nicolas.ferre@...rochip.com>
Subject: [PATCH] clk: at91: clk-sam9x60-pll: force write to PLL_UPDT register
From: Nicolas Ferre <nicolas.ferre@...rochip.com>
This register is important for sequencing the commands to PLLs, so
actually write the update bits with regmap_write_bits() instead of
relying on a read/modify/write regmap command that could skip the actual
hardware write if the value is identical to the one read.
It's changed when modification is needed to the PLL, when
read-only operation is done, we could keep the call to
regmap_update_bits().
Add a comment to the sam9x60_div_pll_set_div() function that uses this
PLL_UPDT register so that it's used consistently, according to the
product's datasheet.
Signed-off-by: Nicolas Ferre <nicolas.ferre@...rochip.com>
Tested-by: Ryan Wanner <ryan.wanner@...rochip.com> # on sama7d65 and sam9x75
---
drivers/clk/at91/clk-sam9x60-pll.c | 33 ++++++++++++++++--------------
1 file changed, 18 insertions(+), 15 deletions(-)
diff --git a/drivers/clk/at91/clk-sam9x60-pll.c b/drivers/clk/at91/clk-sam9x60-pll.c
index cefd9948e103..a3198323126f 100644
--- a/drivers/clk/at91/clk-sam9x60-pll.c
+++ b/drivers/clk/at91/clk-sam9x60-pll.c
@@ -93,7 +93,7 @@ static int sam9x60_frac_pll_set(struct sam9x60_pll_core *core)
spin_lock_irqsave(core->lock, flags);
- regmap_update_bits(regmap, AT91_PMC_PLL_UPDT,
+ regmap_write_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;
@@ -128,7 +128,7 @@ static int sam9x60_frac_pll_set(struct sam9x60_pll_core *core)
udelay(10);
}
- regmap_update_bits(regmap, AT91_PMC_PLL_UPDT,
+ regmap_write_bits(regmap, AT91_PMC_PLL_UPDT,
AT91_PMC_PLL_UPDT_UPDATE | AT91_PMC_PLL_UPDT_ID_MSK,
AT91_PMC_PLL_UPDT_UPDATE | core->id);
@@ -136,7 +136,7 @@ static int sam9x60_frac_pll_set(struct sam9x60_pll_core *core)
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,
+ regmap_write_bits(regmap, AT91_PMC_PLL_UPDT,
AT91_PMC_PLL_UPDT_UPDATE | AT91_PMC_PLL_UPDT_ID_MSK,
AT91_PMC_PLL_UPDT_UPDATE | core->id);
@@ -164,7 +164,7 @@ static void sam9x60_frac_pll_unprepare(struct clk_hw *hw)
spin_lock_irqsave(core->lock, flags);
- regmap_update_bits(regmap, AT91_PMC_PLL_UPDT,
+ regmap_write_bits(regmap, AT91_PMC_PLL_UPDT,
AT91_PMC_PLL_UPDT_ID_MSK, core->id);
regmap_update_bits(regmap, AT91_PMC_PLL_CTRL0, AT91_PMC_PLL_CTRL0_ENPLL, 0);
@@ -173,7 +173,7 @@ static void sam9x60_frac_pll_unprepare(struct clk_hw *hw)
regmap_update_bits(regmap, AT91_PMC_PLL_ACR,
AT91_PMC_PLL_ACR_UTMIBG | AT91_PMC_PLL_ACR_UTMIVR, 0);
- regmap_update_bits(regmap, AT91_PMC_PLL_UPDT,
+ regmap_write_bits(regmap, AT91_PMC_PLL_UPDT,
AT91_PMC_PLL_UPDT_UPDATE | AT91_PMC_PLL_UPDT_ID_MSK,
AT91_PMC_PLL_UPDT_UPDATE | core->id);
@@ -262,7 +262,7 @@ static int sam9x60_frac_pll_set_rate_chg(struct clk_hw *hw, unsigned long rate,
spin_lock_irqsave(core->lock, irqflags);
- regmap_update_bits(regmap, AT91_PMC_PLL_UPDT, AT91_PMC_PLL_UPDT_ID_MSK,
+ regmap_write_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;
@@ -275,7 +275,7 @@ static int sam9x60_frac_pll_set_rate_chg(struct clk_hw *hw, unsigned long rate,
(frac->mul << core->layout->mul_shift) |
(frac->frac << core->layout->frac_shift));
- regmap_update_bits(regmap, AT91_PMC_PLL_UPDT,
+ regmap_write_bits(regmap, AT91_PMC_PLL_UPDT,
AT91_PMC_PLL_UPDT_UPDATE | AT91_PMC_PLL_UPDT_ID_MSK,
AT91_PMC_PLL_UPDT_UPDATE | core->id);
@@ -284,7 +284,7 @@ static int sam9x60_frac_pll_set_rate_chg(struct clk_hw *hw, unsigned long rate,
AT91_PMC_PLL_CTRL0_ENLOCK |
AT91_PMC_PLL_CTRL0_ENPLL);
- regmap_update_bits(regmap, AT91_PMC_PLL_UPDT,
+ regmap_write_bits(regmap, AT91_PMC_PLL_UPDT,
AT91_PMC_PLL_UPDT_UPDATE | AT91_PMC_PLL_UPDT_ID_MSK,
AT91_PMC_PLL_UPDT_UPDATE | core->id);
@@ -338,7 +338,10 @@ static const struct clk_ops sam9x60_frac_pll_ops_chg = {
.restore_context = sam9x60_frac_pll_restore_context,
};
-/* This function should be called with spinlock acquired. */
+/* This function should be called with spinlock acquired.
+ * Warning: this function must be called only if the same PLL ID was set in
+ * PLL_UPDT register previously.
+ */
static void sam9x60_div_pll_set_div(struct sam9x60_pll_core *core, u32 div,
bool enable)
{
@@ -350,7 +353,7 @@ static void sam9x60_div_pll_set_div(struct sam9x60_pll_core *core, u32 div,
core->layout->div_mask | ena_msk,
(div << core->layout->div_shift) | ena_val);
- regmap_update_bits(regmap, AT91_PMC_PLL_UPDT,
+ regmap_write_bits(regmap, AT91_PMC_PLL_UPDT,
AT91_PMC_PLL_UPDT_UPDATE | AT91_PMC_PLL_UPDT_ID_MSK,
AT91_PMC_PLL_UPDT_UPDATE | core->id);
@@ -366,7 +369,7 @@ static int sam9x60_div_pll_set(struct sam9x60_pll_core *core)
unsigned int val, cdiv;
spin_lock_irqsave(core->lock, flags);
- regmap_update_bits(regmap, AT91_PMC_PLL_UPDT,
+ regmap_write_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;
@@ -398,13 +401,13 @@ static void sam9x60_div_pll_unprepare(struct clk_hw *hw)
spin_lock_irqsave(core->lock, flags);
- regmap_update_bits(regmap, AT91_PMC_PLL_UPDT,
+ regmap_write_bits(regmap, AT91_PMC_PLL_UPDT,
AT91_PMC_PLL_UPDT_ID_MSK, core->id);
regmap_update_bits(regmap, AT91_PMC_PLL_CTRL0,
core->layout->endiv_mask, 0);
- regmap_update_bits(regmap, AT91_PMC_PLL_UPDT,
+ regmap_write_bits(regmap, AT91_PMC_PLL_UPDT,
AT91_PMC_PLL_UPDT_UPDATE | AT91_PMC_PLL_UPDT_ID_MSK,
AT91_PMC_PLL_UPDT_UPDATE | core->id);
@@ -518,7 +521,7 @@ static int sam9x60_div_pll_set_rate_chg(struct clk_hw *hw, unsigned long rate,
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,
+ regmap_write_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;
@@ -574,7 +577,7 @@ static int sam9x60_div_pll_notifier_fn(struct notifier_block *notifier,
div->div = div->safe_div;
spin_lock_irqsave(core.lock, irqflags);
- regmap_update_bits(regmap, AT91_PMC_PLL_UPDT, AT91_PMC_PLL_UPDT_ID_MSK,
+ regmap_write_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;
--
2.43.0
Powered by blists - more mailing lists