From: Matthias Wieloch <matthias.wieloch@xxxxxxxxxxxx>
The prescaler formula of the programmable clock has changed for sama5d2. Update
the driver accordingly.
Fixes: a2038077de9a ("clk: at91: add sama5d2 PMC driver")
Cc: <stable@xxxxxxxxxxxxxxx> # v4.20+
Signed-off-by: Nicolas Ferre <nicolas.ferre@xxxxxxxxxxxxx>
[nicolas.ferre@xxxxxxxxxxxxx: adapt the prescaler range,
fix clk_programmable_recalc_rate, split patch]
Signed-off-by: Matthias Wieloch <matthias.wieloch@xxxxxxxxxxxx>
Signed-off-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx>
---
v2: adapt to v5.1-rc1
remove unneeded sentence about DT in commit message
Stephen,
I think it would be good to see this fix going upstream during v5.1-rc phase.
Best regards,
Nicolas
drivers/clk/at91/clk-programmable.c | 57 ++++++++++++++++++++++-------
drivers/clk/at91/pmc.h | 2 +
drivers/clk/at91/sama5d2.c | 10 ++++-
3 files changed, 54 insertions(+), 15 deletions(-)
diff --git a/drivers/clk/at91/clk-programmable.c b/drivers/clk/at91/clk-programmable.c
index 89d6f3736dbf..f8edbb65eda3 100644
--- a/drivers/clk/at91/clk-programmable.c
+++ b/drivers/clk/at91/clk-programmable.c
@@ -20,8 +20,7 @@
#define PROG_ID_MAX 7
#define PROG_STATUS_MASK(id) (1 << ((id) + 8))
-#define PROG_PRES_MASK 0x7
-#define PROG_PRES(layout, pckr) ((pckr >> layout->pres_shift) & PROG_PRES_MASK)
+#define PROG_PRES(layout, pckr) ((pckr >> layout->pres_shift) & layout->pres_mask)
#define PROG_MAX_RM9200_CSS 3
struct clk_programmable {
@@ -37,20 +36,29 @@ static unsigned long clk_programmable_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct clk_programmable *prog = to_clk_programmable(hw);
+ const struct clk_programmable_layout *layout = prog->layout;
unsigned int pckr;
+ unsigned long rate;
regmap_read(prog->regmap, AT91_PMC_PCKR(prog->id), &pckr);
- return parent_rate >> PROG_PRES(prog->layout, pckr);
+ if (layout->is_pres_direct)
+ rate = parent_rate / (PROG_PRES(layout, pckr) + 1);
+ else
+ rate = parent_rate >> PROG_PRES(layout, pckr);
+
+ return rate;
}
static int clk_programmable_determine_rate(struct clk_hw *hw,
struct clk_rate_request *req)
{
+ struct clk_programmable *prog = to_clk_programmable(hw);
+ const struct clk_programmable_layout *layout = prog->layout;
struct clk_hw *parent;
long best_rate = -EINVAL;
unsigned long parent_rate;
- unsigned long tmp_rate;
+ unsigned long tmp_rate = 0;
int shift;
int i;
@@ -60,10 +68,18 @@ static int clk_programmable_determine_rate(struct clk_hw *hw,
continue;
parent_rate = clk_hw_get_rate(parent);
- for (shift = 0; shift < PROG_PRES_MASK; shift++) {
- tmp_rate = parent_rate >> shift;
- if (tmp_rate <= req->rate)
- break;
+ if (layout->is_pres_direct) {
+ for (shift = 0; shift <= layout->pres_mask; shift++) {
+ tmp_rate = parent_rate / (shift + 1);
+ if (tmp_rate <= req->rate)
+ break;
+ }
+ } else {
+ for (shift = 0; shift < layout->pres_mask; shift++) {
+ tmp_rate = parent_rate >> shift;
+ if (tmp_rate <= req->rate)
+ break;
+ }
}
if (tmp_rate > req->rate)
@@ -137,16 +153,23 @@ static int clk_programmable_set_rate(struct clk_hw *hw, unsigned long rate,
if (!div)
return -EINVAL;
- shift = fls(div) - 1;
+ if (layout->is_pres_direct) {
+ shift = div - 1;
- if (div != (1 << shift))
- return -EINVAL;
+ if (shift > layout->pres_mask)
+ return -EINVAL;
+ } else {
+ shift = fls(div) - 1;
- if (shift >= PROG_PRES_MASK)
- return -EINVAL;
+ if (div != (1 << shift))
+ return -EINVAL;
+
+ if (shift >= layout->pres_mask)
+ return -EINVAL;
+ }
regmap_update_bits(prog->regmap, AT91_PMC_PCKR(prog->id),
- PROG_PRES_MASK << layout->pres_shift,
+ layout->pres_mask << layout->pres_shift,
shift << layout->pres_shift);
return 0;
@@ -202,19 +225,25 @@ at91_clk_register_programmable(struct regmap *regmap,
}
const struct clk_programmable_layout at91rm9200_programmable_layout = {
+ .pres_mask = 0x7,
.pres_shift = 2,
.css_mask = 0x3,
.have_slck_mck = 0,
+ .is_pres_direct = 0,
};
const struct clk_programmable_layout at91sam9g45_programmable_layout = {
+ .pres_mask = 0x7,
.pres_shift = 2,
.css_mask = 0x3,
.have_slck_mck = 1,
+ .is_pres_direct = 0,
};
const struct clk_programmable_layout at91sam9x5_programmable_layout = {
+ .pres_mask = 0x7,
.pres_shift = 4,
.css_mask = 0x7,
.have_slck_mck = 0,
+ .is_pres_direct = 0,
};
diff --git a/drivers/clk/at91/pmc.h b/drivers/clk/at91/pmc.h
index 672a79bda88c..a0e5ce9c9b9e 100644
--- a/drivers/clk/at91/pmc.h
+++ b/drivers/clk/at91/pmc.h
@@ -71,9 +71,11 @@ struct clk_pll_characteristics {
};
struct clk_programmable_layout {
+ u8 pres_mask;
u8 pres_shift;
u8 css_mask;
u8 have_slck_mck;
+ u8 is_pres_direct;
};
extern const struct clk_programmable_layout at91rm9200_programmable_layout;
diff --git a/drivers/clk/at91/sama5d2.c b/drivers/clk/at91/sama5d2.c
index 1f70cb164b06..81943fac4537 100644
--- a/drivers/clk/at91/sama5d2.c
+++ b/drivers/clk/at91/sama5d2.c
@@ -125,6 +125,14 @@ static const struct {
.pll = true },
};
+static const struct clk_programmable_layout sama5d2_programmable_layout = {
+ .pres_mask = 0xff,
+ .pres_shift = 4,
+ .css_mask = 0x7,
+ .have_slck_mck = 0,
+ .is_pres_direct = 1,
+};
+
static void __init sama5d2_pmc_setup(struct device_node *np)
{
struct clk_range range = CLK_RANGE(0, 0);
@@ -249,7 +257,7 @@ static void __init sama5d2_pmc_setup(struct device_node *np)
hw = at91_clk_register_programmable(regmap, name,
parent_names, 6, i,
- &at91sam9x5_programmable_layout);
+ &sama5d2_programmable_layout);
if (IS_ERR(hw))
goto err_free;
}
--
2.17.1
