UPSTREAM: drm: bridge: dw-hdmi: Reject invalid product IDs

The DWC HDMI TX can be recognized by the two product identification
registers. If the registers don't read as expect the IP will be very
different than what the driver has been designed for, or will be
misconfigured in a way that makes it non-operational (invalid memory
address, incorrect clocks, ...). We should reject this situation with an
error.

While this isn't critical for proper operation with supported IPs at the
moment, the driver will soon gain automatic device-specific handling
based on runtime device identification. This change makes it easier to
implement that without having to default to a random guess in case the
device can't be identified.

While at it print a readable version number in the device identification
message instead of raw register values.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Jose Abreu <joabreu@synopsys.com>
Signed-off-by: Archit Taneja <architt@codeaurora.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20170117082910.27023-14-laurent.pinchart+renesas@ideasonboard.com
Change-Id: Iaa8e17429e9b4033f97b2bf49504e6f390ce7c44
Signed-off-by: Zheng Yang <zhengyang@rock-chips.com>
(cherry pick from 0527e12e8264ae96b1fcc550b4a9e5940f4ffc30)

diff --git a/drivers/gpu/drm/bridge/dw-hdmi.c b/drivers/gpu/drm/bridge/dw-hdmi.c
index 901477a79c8b598140c5699e9976be6df01a724f..706dc344cc1c406ae2ae62d972ca3fdda73d3189 100644 (file)
--- a/drivers/gpu/drm/bridge/dw-hdmi.c
+++ b/drivers/gpu/drm/bridge/dw-hdmi.c
@@ -2402,6 +2402,9 @@ int dw_hdmi_bind(struct device *dev, struct device *master,
        struct dw_hdmi *hdmi;
        int ret;
        u32 val = 1;
+       u16 version;
+       u8 prod_id0;
+       u8 prod_id1;
        u8 config0;
        u8 config1;
 
@@ -2503,12 +2506,22 @@ int dw_hdmi_bind(struct device *dev, struct device *master,
        }
 
        /* Product and revision IDs */
-       dev_info(dev,
-                "Detected HDMI controller 0x%x:0x%x:0x%x:0x%x\n",
-                hdmi_readb(hdmi, HDMI_DESIGN_ID),
-                hdmi_readb(hdmi, HDMI_REVISION_ID),
-                hdmi_readb(hdmi, HDMI_PRODUCT_ID0),
-                hdmi_readb(hdmi, HDMI_PRODUCT_ID1));
+       version = (hdmi_readb(hdmi, HDMI_DESIGN_ID) << 8)
+               | (hdmi_readb(hdmi, HDMI_REVISION_ID) << 0);
+       prod_id0 = hdmi_readb(hdmi, HDMI_PRODUCT_ID0);
+       prod_id1 = hdmi_readb(hdmi, HDMI_PRODUCT_ID1);
+
+       if (prod_id0 != HDMI_PRODUCT_ID0_HDMI_TX ||
+           (prod_id1 & ~HDMI_PRODUCT_ID1_HDCP) != HDMI_PRODUCT_ID1_HDMI_TX) {
+               dev_err(dev, "Unsupported HDMI controller (%04x:%02x:%02x)\n",
+                       version, prod_id0, prod_id1);
+               ret = -ENODEV;
+               goto err_iahb;
+       }
+
+       dev_info(dev, "Detected HDMI TX controller v%x.%03x %s HDCP\n",
+                version >> 12, version & 0xfff,
+                prod_id1 & HDMI_PRODUCT_ID1_HDCP ? "with" : "without");
 
        init_hpd_work(hdmi);
        initialize_hdmi_ih_mutes(hdmi);

diff --git a/drivers/gpu/drm/bridge/dw-hdmi.h b/drivers/gpu/drm/bridge/dw-hdmi.h
index f8e25c926e62862adb2367ee7bd33f575ed307b9..29218a56ba7777b9ed261913f6ad31f925d580fc 100644 (file)
--- a/drivers/gpu/drm/bridge/dw-hdmi.h
+++ b/drivers/gpu/drm/bridge/dw-hdmi.h
@@ -556,6 +556,13 @@
 #define HDMI_I2CM_SDA_HOLD                      0x7E13
 
 enum {
+/* PRODUCT_ID0 field values */
+       HDMI_PRODUCT_ID0_HDMI_TX = 0xa0,
+
+/* PRODUCT_ID1 field values */
+       HDMI_PRODUCT_ID1_HDCP = 0xc0,
+       HDMI_PRODUCT_ID1_HDMI_RX = 0x02,
+       HDMI_PRODUCT_ID1_HDMI_TX = 0x01,
 
 /* CONFIG0_ID field values */
        HDMI_CONFIG0_I2S = 0x10,