[PATCH 12/20] drm/bridge: tc358775: correctly configure LVDS clock

From: Michael Walle
Date: Mon May 06 2024 - 09:39:16 EST


The driver assumes a DSI link with four lanes for now and has the LVDS
clock divider hardcoded to either 3 or 6. Take the number of lanes into
account, too. Also, explicitly set the clock source to the DSI clock.

While at it, replace the TC358775_LVCFG_PCLKDIV() and
TC358775_LVCFG_LVDLINK() inline functions style by the more common
linux bitfields functions.

Signed-off-by: Michael Walle <mwalle@xxxxxxxxxx>
---
drivers/gpu/drm/bridge/tc358775.c | 48 +++++++++++++++++----------------------
1 file changed, 21 insertions(+), 27 deletions(-)

diff --git a/drivers/gpu/drm/bridge/tc358775.c b/drivers/gpu/drm/bridge/tc358775.c
index e6d1f0c686ac..eea41054c6fa 100644
--- a/drivers/gpu/drm/bridge/tc358775.c
+++ b/drivers/gpu/drm/bridge/tc358775.c
@@ -139,6 +139,12 @@ enum {
};

#define LVCFG 0x049C /* LVDS Configuration */
+#define LVCFG_LVEN BIT(0)
+#define LVCFG_LVDLINK BIT(1)
+#define LVCFG_PCLKDIV GENMASK(7, 4)
+#define LVCFG_PCLKSEL GENMASK(11, 10)
+#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)
@@ -183,28 +189,8 @@ enum {
#define DEBUG01 0x05A4 /* LVDS Data */

#define DSI_CLEN_BIT BIT(0)
-#define DIVIDE_BY_3 3 /* PCLK=DCLK/3 */
-#define DIVIDE_BY_6 6 /* PCLK=DCLK/6 */
-#define LVCFG_LVEN_BIT BIT(0)
-
#define L0EN BIT(1)

-#define TC358775_LVCFG_PCLKDIV__MASK 0x000000f0
-#define TC358775_LVCFG_PCLKDIV__SHIFT 4
-static inline u32 TC358775_LVCFG_PCLKDIV(uint32_t val)
-{
- return ((val) << TC358775_LVCFG_PCLKDIV__SHIFT) &
- TC358775_LVCFG_PCLKDIV__MASK;
-}
-
-#define TC358775_LVCFG_LVDLINK__MASK 0x00000002
-#define TC358775_LVCFG_LVDLINK__SHIFT 1
-static inline u32 TC358775_LVCFG_LVDLINK(uint32_t val)
-{
- return ((val) << TC358775_LVCFG_LVDLINK__SHIFT) &
- TC358775_LVCFG_LVDLINK__MASK;
-}
-
enum tc358775_ports {
TC358775_DSI_IN,
TC358775_LVDS_OUT0,
@@ -327,6 +313,8 @@ static void tc_bridge_enable(struct drm_bridge *bridge)
struct tc_data *tc = bridge_to_tc(bridge);
u32 hback_porch, hsync_len, hfront_porch, hactive, htime1, htime2;
u32 vback_porch, vsync_len, vfront_porch, vactive, vtime1, vtime2;
+ int bpp = mipi_dsi_pixel_format_to_bpp(tc->dsi->format);
+ int clkdiv;
unsigned int val = 0;
struct drm_display_mode *mode;
struct drm_connector *connector = get_connector(bridge->encoder);
@@ -408,14 +396,20 @@ static void tc_bridge_enable(struct drm_bridge *bridge)

regmap_write(tc->regmap, VFUEN, VFUEN_EN);

- val = LVCFG_LVEN_BIT;
- if (tc->lvds_dual_link) {
- val |= TC358775_LVCFG_LVDLINK(1);
- val |= TC358775_LVCFG_PCLKDIV(DIVIDE_BY_6);
- } else {
- val |= TC358775_LVCFG_PCLKDIV(DIVIDE_BY_3);
- }
+ /* Configure LVDS clock */
+ clkdiv = bpp / tc->num_dsi_lanes;
+ if (!tc->lvds_dual_link)
+ clkdiv /= 2;
+
+ val = u32_encode_bits(clkdiv, LVCFG_PCLKDIV);
+ val |= u32_encode_bits(PCLKSEL_HSRCK, LVCFG_PCLKSEL);
+ if (tc->lvds_dual_link)
+ val |= LVCFG_LVDLINK;
+
regmap_write(tc->regmap, LVCFG, val);
+
+ /* Finally, enable the LVDS transmitter */
+ regmap_write(tc->regmap, LVCFG, val | LVCFG_LVEN);
}

/*

--
2.39.2