From 0527e12e8264ae96b1fcc550b4a9e5940f4ffc30 Mon Sep 17 00:00:00 2001 From: Laurent Pinchart Date: Tue, 17 Jan 2017 10:29:03 +0200 Subject: [PATCH] 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 Reviewed-by: Jose Abreu Signed-off-by: Archit Taneja Link: http://patchwork.freedesktop.org/patch/msgid/20170117082910.27023-14-laurent.pinchart+renesas@ideasonboard.com --- drivers/gpu/drm/bridge/dw-hdmi.c | 25 +++++++++++++++++++------ drivers/gpu/drm/bridge/dw-hdmi.h | 8 ++++++++ 2 files changed, 27 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/bridge/dw-hdmi.c b/drivers/gpu/drm/bridge/dw-hdmi.c index 06c252f560ad..1809247745b8 100644 --- a/drivers/gpu/drm/bridge/dw-hdmi.c +++ b/drivers/gpu/drm/bridge/dw-hdmi.c @@ -1832,6 +1832,9 @@ __dw_hdmi_probe(struct platform_device *pdev, int irq; int ret; u32 val = 1; + u16 version; + u8 prod_id0; + u8 prod_id1; u8 config0; u8 config1; @@ -1914,12 +1917,22 @@ __dw_hdmi_probe(struct platform_device *pdev, } /* 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"); initialize_hdmi_ih_mutes(hdmi); diff --git a/drivers/gpu/drm/bridge/dw-hdmi.h b/drivers/gpu/drm/bridge/dw-hdmi.h index 08235aef2fa3..91d7fabbd6e5 100644 --- a/drivers/gpu/drm/bridge/dw-hdmi.h +++ b/drivers/gpu/drm/bridge/dw-hdmi.h @@ -545,6 +545,14 @@ #define HDMI_I2CM_FS_SCL_LCNT_0_ADDR 0x7E12 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, -- 2.20.1