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.
Signed-off-by: Marek Vasut <[email protected]> Cc: Jagan Teki <[email protected]> Cc: Robert Foss <[email protected]> Cc: Sam Ravnborg <[email protected]> Cc: Thomas Zimmermann <[email protected]> To: [email protected] --- 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 3023edb6f31b5..85cba739afd9c 100644 --- a/drivers/gpu/drm/bridge/chipone-icn6211.c +++ b/drivers/gpu/drm/bridge/chipone-icn6211.c @@ -176,6 +176,14 @@ bridge_to_mode(struct drm_bridge *bridge, struct drm_atomic_state *state) return &crtc_state->adjusted_mode; } +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 void chipone_writeb(struct chipone *icn, u8 reg, u8 val) { if (icn->interface_i2c) @@ -274,7 +282,21 @@ 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); -- 2.34.1
