[PATCH v2 09/18] drm/sun4i: Create minimal multipliers and dividers

Maxime Ripard
2017-11-27T15:41:33Z

The various outputs the TCON can provide have different constraints on the
dotclock divider. Let's make them configurable by the various mode_set
functions.

Reviewed-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
drivers/gpu/drm/sun4i/sun4i_dotclock.c | 10 +++++++---
drivers/gpu/drm/sun4i/sun4i_tcon.c | 2 ++
drivers/gpu/drm/sun4i/sun4i_tcon.h | 2 ++
3 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/sun4i/sun4i_dotclock.c b/drivers/gpu/drm/sun4i/sun4i_dotclock.c
index d401156490f3..023f39bda633 100644
--- a/drivers/gpu/drm/sun4i/sun4i_dotclock.c
+++ b/drivers/gpu/drm/sun4i/sun4i_dotclock.c
@@ -17,8 +17,9 @@
#include "sun4i_dotclock.h"

struct sun4i_dclk {
- struct clk_hw hw;
- struct regmap *regmap;
+ struct clk_hw hw;
+ struct regmap *regmap;
+ struct sun4i_tcon *tcon;
};

static inline struct sun4i_dclk *hw_to_dclk(struct clk_hw *hw)
@@ -73,11 +74,13 @@ static unsigned long sun4i_dclk_recalc_rate(struct clk_hw *hw,
static long sun4i_dclk_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *parent_rate)
{
+ struct sun4i_dclk *dclk = hw_to_dclk(hw);
+ struct sun4i_tcon *tcon = dclk->tcon;
unsigned long best_parent = 0;
u8 best_div = 1;
int i;

- for (i = 6; i <= 127; i++) {
+ for (i = tcon->dclk_min_div; i <= tcon->dclk_max_div; i++) {
unsigned long ideal = rate * i;
unsigned long rounded;

@@ -167,6 +170,7 @@ int sun4i_dclk_create(struct device *dev, struct sun4i_tcon *tcon)
dclk = devm_kzalloc(dev, sizeof(*dclk), GFP_KERNEL);
if (!dclk)
return -ENOMEM;
+ dclk->tcon = tcon;

init.name = clk_name;
init.ops = &sun4i_dclk_ops;
diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c
index f4284b51bdca..5b6cd7c43e4b 100644
--- a/drivers/gpu/drm/sun4i/sun4i_tcon.c
+++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c
@@ -177,6 +177,8 @@ static void sun4i_tcon0_mode_set_rgb(struct sun4i_tcon *tcon,
u8 clk_delay;
u32 val = 0;

+ tcon->dclk_min_div = 6;
+ tcon->dclk_max_div = 127;
sun4i_tcon0_mode_set_common(tcon, mode);

/* Adjust clock delay */
diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.h b/drivers/gpu/drm/sun4i/sun4i_tcon.h
index f61bf6d83b4a..4141fbd97ddf 100644
--- a/drivers/gpu/drm/sun4i/sun4i_tcon.h
+++ b/drivers/gpu/drm/sun4i/sun4i_tcon.h
@@ -169,6 +169,8 @@ struct sun4i_tcon {

/* Pixel clock */
struct clk *dclk;
+ u8 dclk_max_div;
+ u8 dclk_min_div;

/* Reset control */
struct reset_control *lcd_rst;
--
git-series 0.9.1