Read out the Vendor/Chip/Version ID registers from the chip before performing any configuration, and validate that the registers have correct values. This is mostly a simple test whether DSI register access does work, since that tends to be broken on various bridges.
Acked-by: Maxime Ripard maxime@cerno.tech Signed-off-by: Marek Vasut marex@denx.de Cc: Jagan Teki jagan@amarulasolutions.com Cc: Maxime Ripard maxime@cerno.tech Cc: Robert Foss robert.foss@linaro.org Cc: Sam Ravnborg sam@ravnborg.org Cc: Thomas Zimmermann tzimmermann@suse.de To: dri-devel@lists.freedesktop.org --- V2: Rebase on next-20220214 V3: Add AB from Maxime V4: No change V5: No change V6: No change --- drivers/gpu/drm/bridge/chipone-icn6211.c | 24 +++++++++++++++++++++++- 1 file changed, 23 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/bridge/chipone-icn6211.c b/drivers/gpu/drm/bridge/chipone-icn6211.c index f4dfb2297c71..a1bdb9be1927 100644 --- a/drivers/gpu/drm/bridge/chipone-icn6211.c +++ b/drivers/gpu/drm/bridge/chipone-icn6211.c @@ -151,6 +151,14 @@ static inline struct chipone *bridge_to_chipone(struct drm_bridge *bridge) return container_of(bridge, struct chipone, bridge); }
+static void chipone_readb(struct chipone *icn, u8 reg, u8 *val) +{ + if (icn->interface_i2c) + *val = i2c_smbus_read_byte_data(icn->client, reg); + else + mipi_dsi_generic_read(icn->dsi, (u8[]){reg, 1}, 2, val, 1); +} + static int chipone_writeb(struct chipone *icn, u8 reg, u8 val) { if (icn->interface_i2c) @@ -250,7 +258,21 @@ static void chipone_atomic_enable(struct drm_bridge *bridge, const struct drm_bridge_state *bridge_state; u16 hfp, hbp, hsync; u32 bus_flags; - u8 pol; + u8 pol, id[4]; + + chipone_readb(icn, VENDOR_ID, id); + chipone_readb(icn, DEVICE_ID_H, id + 1); + chipone_readb(icn, DEVICE_ID_L, id + 2); + chipone_readb(icn, VERSION_ID, id + 3); + + dev_dbg(icn->dev, + "Chip IDs: Vendor=0x%02x Device=0x%02x:0x%02x Version=0x%02x\n", + id[0], id[1], id[2], id[3]); + + if (id[0] != 0xc1 || id[1] != 0x62 || id[2] != 0x11) { + dev_dbg(icn->dev, "Invalid Chip IDs, aborting configuration\n"); + return; + }
/* Get the DPI flags from the bridge state. */ bridge_state = drm_atomic_get_new_bridge_state(state, bridge);