[PATCH 14/20] drm/bridge: tc358775: configure PLL depending on the LVDS clock

From: Michael Walle
Date: Mon May 06 2024 - 09:39:40 EST


The PLL setting was hardcoded to a LVDS clock between 60MHz and 135MHz.
This adds support for slower frequencies. Also, rework the reset
sequence to match the initialization sequence provided by the vendor.

Signed-off-by: Michael Walle <mwalle@xxxxxxxxxx>
---
drivers/gpu/drm/bridge/tc358775.c | 50 ++++++++++++++++++++++++++++++++-------
1 file changed, 42 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/bridge/tc358775.c b/drivers/gpu/drm/bridge/tc358775.c
index 4ec059531c5f..e3fba7ac71ec 100644
--- a/drivers/gpu/drm/bridge/tc358775.c
+++ b/drivers/gpu/drm/bridge/tc358775.c
@@ -30,8 +30,6 @@
#include <drm/drm_panel.h>
#include <drm/drm_probe_helper.h>

-#define FLD_VAL(val, start, end) FIELD_PREP(GENMASK(start, end), val)
-
/* Registers */

/* DSI D-PHY Layer Registers */
@@ -146,10 +144,10 @@ enum {
#define PCLKSEL_HSRCK 0 /* DSI clock */

#define LVPHY0 0x04A0 /* LVDS PHY 0 */
-#define LV_PHY0_RST(v) FLD_VAL(v, 22, 22) /* PHY reset */
-#define LV_PHY0_IS(v) FLD_VAL(v, 15, 14)
-#define LV_PHY0_ND(v) FLD_VAL(v, 4, 0) /* Frequency range select */
-#define LV_PHY0_PRBS_ON(v) FLD_VAL(v, 20, 16) /* Clock/Data Flag pins */
+#define LVPHY0_LV_ND GENMASK(4, 0)
+#define LVPHY0_LV_FS GENMASK(6, 5)
+#define LVPHY0_LV_IS GENMASK(15, 14) /* charge pump current */
+#define LVPHY0_LV_RST BIT(22)

#define LVPHY1 0x04A4 /* LVDS PHY 1 */
#define SYSSTAT 0x0500 /* System Status */
@@ -223,6 +221,14 @@ struct tc_data {
enum tc3587x5_type type;
};

+struct tc358775_pll_settings {
+ unsigned int min_khz;
+ unsigned int max_khz;
+ u8 fs;
+ u8 nd;
+ u8 is;
+};
+
static inline struct tc_data *bridge_to_tc(struct drm_bridge *b)
{
return container_of(b, struct tc_data, bridge);
@@ -371,10 +377,38 @@ static void tc358775_configure_lvds_timings(struct tc_data *tc,
regmap_write(tc->regmap, VFUEN, VFUEN_EN);
}

-static void tc358775_configure_pll(struct tc_data *tc, int pixelclk)
+static const struct tc358775_pll_settings tc358775_pll_settings[] = {
+ { 25000, 30000, 2, 27, 1 },
+ { 30000, 60000, 1, 13, 1 },
+ { 60000, 135000, 0, 6, 1 },
+ {}
+};
+
+static void tc358775_configure_pll(struct tc_data *tc, unsigned int pixelclk)
{
+ const struct tc358775_pll_settings *settings;
+ unsigned int val;
+
+ if (tc->lvds_dual_link)
+ pixelclk /= 2;
+
+ for (settings = tc358775_pll_settings; settings->min_khz; settings++)
+ if (pixelclk > settings->min_khz &&
+ pixelclk < settings->max_khz)
+ break;
+
+ if (!settings->min_khz)
+ return;
+
+ val = u32_encode_bits(settings->fs, LVPHY0_LV_FS);
+ val |= u32_encode_bits(settings->nd, LVPHY0_LV_ND);
+ val |= u32_encode_bits(settings->is, LVPHY0_LV_IS);
+
+ regmap_write(tc->regmap, LVPHY0, val | LVPHY0_LV_RST);
+ usleep_range(100, 150);
+ regmap_write(tc->regmap, LVPHY0, val);
+
regmap_write(tc->regmap, SYSRST, SYS_RST_LCD);
- regmap_write(tc->regmap, LVPHY0, LV_PHY0_PRBS_ON(4) | LV_PHY0_ND(6));
}

static void tc358775_configure_color_mapping(struct tc_data *tc, u32 fmt)

--
2.39.2