From: Martin Sperl <kernel@xxxxxxxxxxxxxxxx>
Control maximum mash levels that can get used via the device tree.
Signed-off-by: Martin Sperl <kernel@xxxxxxxxxxxxxxxx>
---
drivers/clk/bcm/clk-bcm2835.c | 39 +++++++++++++++++++++++++++--------
include/dt-bindings/clock/bcm2835.h | 9 ++++++++
2 files changed, 39 insertions(+), 9 deletions(-)
diff --git a/drivers/clk/bcm/clk-bcm2835.c b/drivers/clk/bcm/clk-bcm2835.c
index 8fccbd3..48c1ad0 100644
--- a/drivers/clk/bcm/clk-bcm2835.c
+++ b/drivers/clk/bcm/clk-bcm2835.c
@@ -303,10 +303,10 @@
#define BCM2835_MASH_MAX_FREQ 25000000u
enum bcm2835_clock_mash_type {
- MASH_NONE = 0,
- MASH_FRAC = 1,
- MASH_2ND_ORDER = 2,
- MASH_3RD_ORDER = 3
+ MASH_NONE = BCM2835_MASH_NONE,
+ MASH_FRAC = BCM2835_MASH_FRAC,
+ MASH_ORDER_2 = BCM2835_MASH_ORDER_2,
+ MASH_ORDER_3 = BCM2835_MASH_ORDER_3
};
/*
@@ -713,6 +713,7 @@ struct bcm2835_clock_data {
u32 frac_bits;
/* the mash value to use - see CM_MASH */
enum bcm2835_clock_mash_type mash;
+ bool mash_forced;
bool is_vpu_clock;
};
@@ -1508,7 +1509,7 @@ static divmash bcm2835_clock_choose_div(struct clk_hw *hw,
/* select mash mode */
if (data->frac_bits && divf)
- mash = data->mash ? data->mash : MASH_FRAC;
+ mash = data->mash_forced ? data->mash : MASH_FRAC;
/*
* handle possible limits for different mash levels with fall-tru
@@ -1517,17 +1518,17 @@ static divmash bcm2835_clock_choose_div(struct clk_hw *hw,
* http://elinux.org/BCM2835_datasheet_errata#p105_table
*/
switch (mash) {
- case MASH_3RD_ORDER:
+ case MASH_ORDER_3:
if ((divi >= divi_min + 3) &&
(divi + 4 <= divi_max) &&
(parent_rate / (divi - 3) <= BCM2835_MASH_MAX_FREQ))
- return divmash_calc(MASH_3RD_ORDER, div);
+ return divmash_calc(MASH_ORDER_3, div);
/* fall tru if not in bounds */
- case MASH_2ND_ORDER:
+ case MASH_ORDER_2:
if ((divi >= divi_min + 1) &&
(divi + 2 <= divi_max) &&
(parent_rate / (divi - 1) <= BCM2835_MASH_MAX_FREQ))
- return divmash_calc(MASH_2ND_ORDER, div);
+ return divmash_calc(MASH_ORDER_2, div);
/* fall tru if not in bounds */
case MASH_FRAC:
if ((divi >= divi_min) &&
@@ -1993,6 +1994,8 @@ static const struct bcm2835_clock_data *bcm2835_register_clock_of(
struct device *dev = cprman->dev;
struct device_node *nc;
struct bcm2835_clock_data *data;
+ int err;
+ u32 value;
/* find the corresponding dt-node */
nc = bcm2835_find_dt_node(cprman, id);
@@ -2008,6 +2011,24 @@ static const struct bcm2835_clock_data *bcm2835_register_clock_of(
/* apply overrides */
bcm2835_register_clock_of_parents(cprman, data, nc);
+ /* check for mash */
+ err = of_property_read_u32(nc, "brcm,mash-max-order", &value);
+ if (!err) {
+ switch (value) {
+ case MASH_NONE:
+ case MASH_FRAC:
+ case MASH_ORDER_2:
+ case MASH_ORDER_3:
+ data->mash = value;
+ data->mash_forced = 1;
+ break;
+ default:
+ dev_err(dev, "clock %s: undefined mash type: %d\n",
+ data->name, value);
+ break;
+ }
+ }
+
/* and return the result */
return data;
}
diff --git a/include/dt-bindings/clock/bcm2835.h b/include/dt-bindings/clock/bcm2835.h
index d29f181..eb73380 100644
--- a/include/dt-bindings/clock/bcm2835.h
+++ b/include/dt-bindings/clock/bcm2835.h
@@ -67,3 +67,12 @@
#define BCM2835_CLOCK_TD0 51
#define BCM2835_CLOCK_TD1 52
#define BCM2835_CLOCK_TEC 53
+
+/* the mash divider options */
+#define BCM2835_MASH_NONE 0
+#define BCM2835_MASH_ORDER_1 1
+#define BCM2835_MASH_ORDER_2 2
+#define BCM2835_MASH_ORDER_3 3
+
+#define BCM2835_MASH_INTEGER BCM2835_MASH_NONE
+#define BCM2835_MASH_FRAC BCM2835_MASH_ORDER_1
--
1.7.10.4
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