On Wed, Aug 24, 2016 at 08:46:37AM +0300, Vladimir Zapolskiy wrote: > The change adds support of internal HDMI I2C master controller, this > subdevice is used by default, if "ddc-i2c-bus" DT property is omitted. > > The main purpose of this functionality is to support reading EDID from > an HDMI monitor on boards, which don't have an I2C bus connected to > DDC pins. > > The current implementation does not support "I2C Master Interface > Extended Read Mode" to read data addressed by non-zero segment > pointer, this means that if EDID has more than 1 extension blocks, > EDID reading operation won't succeed, in my practice all tested HDMI > monitors have at maximum one extension block. > > Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@xxxxxxxxxx> > --- > The change is based on top of v4.8.0-rc1 and a fix in DW HDMI driver > https://patchwork.kernel.org/patch/9284717/ > > Changes from v5 to v6: > * rebased on top of v4.8.0-rc1 > * fixed one improper resource deallocation on error path of dw_hdmi_bind() > * added a comment describing a mutex asked by checkpatch.pl --strict > > Link to version v5: https://patchwork.kernel.org/patch/7279831/ > > Changes from v4 to v5: > * do I2C bus controller initialization only once in bind() as it was done > in v1-v3 of the change. > > Changes from v3 to v4, thanks to Doug and Philipp for review: > * set speed mode after software reset in dw_hdmi_i2c_init() > * by default set standard speed mode instead of fast speed mode, on iMX6Q > this configures SCL to 100 KHz, which is compliant with HDMI 1.3a spec > * do I2C bus controller reinitialization on every data transfer, > this change hopefully solves some observed problems on RK3288 platform > * added short functional change description to dw_hdmi.txt > > v3 of the change was > > Tested-by: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx> > > Changes from v2 to v3, thanks to Russell: > * moved register field value definitions to dw_hdmi.h > * made completions uninterruptible to avoid transfer retries if interrupted > * use one completion for both read and write transfers as in v1, > operation_reg is removed > * redundant i2c->stat = 0 is removed from dw_hdmi_i2c_read/write() > * struct i2c_algorithm dw_hdmi_algorithm is qualified as const > * dw_hdmi_i2c_adapter() does not modify struct dw_hdmi on error path > * dw_hdmi_i2c_irq() does not modify hdmi->i2c->stat, if interrupt is > not for I2CM > * spin lock is removed from dw_hdmi_i2c_irq() > * removed spin lock from dw_hdmi_i2c_xfer() around write to > HDMI_IH_MUTE_I2CM_STAT0 register > * split loop over message array in dw_hdmi_i2c_xfer() to validation > and transfer parts > * added a mutex to serialize I2C transfer requests, i2c->lock is > completely removed > * removed if(len) check from dw_hdmi_i2c_write(), hardware supports > only len>0 transfers > * described extension blocks <= 1 limitation in the commit message > * a number of minor clean ups > > Changes from v1 to v2: > * fixed a devm_kfree() signature > * split completions for read and write operations > > .../devicetree/bindings/display/bridge/dw_hdmi.txt | 4 +- Acked-by: Rob Herring <robh@xxxxxxxxxx> > drivers/gpu/drm/bridge/dw-hdmi.c | 265 ++++++++++++++++++++- > drivers/gpu/drm/bridge/dw-hdmi.h | 19 ++ > 3 files changed, 281 insertions(+), 7 deletions(-) _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
