Hi Philippe, (please avoid top posting) On 05/15/2017 12:33 PM, Philippe CORNU wrote: > Hi Neil, > Many thanks for your comments. > > The PHY part of the MIPI DSI is the main difference between all chipsets > based on the Synopsys DesignWare MIPI DSI. > There is no "generic DSI PHY interface" and that is probably why all soc > vendors have implemented their own drivers (RockChip, NXP/Freescale, > HiSilicon and now STM32). Sure, this is the same with the DW-HDMI, there is a Synopsys PHY, but also vendor PHYs. > > Regarding creating a "generic dw MIPI DSI bridge" as the recent dw hdmi > bridge, several attempts have been done in the past but without success: > * Liu Ying from Freescale in February 2015 > (https://lkml.org/lkml/2015/2/12/38). > * Chris Zhong from Rockchip in November 2015 > (http://www.mail-archive.com/linux-kernel@xxxxxxxxxxxxxxx/msg1024586.html). "Impossible n'est pas français !" (Georges Courteline, Le 51e Chasseurs, Marpon et Flammario, 1887, p. 23) I think it's worth the try, and will avoid a lot of code duplication among these drivers. And since it's a Synopsys IP, it will continue to appear in current and future SoCs. > > The Rockchip driver looks nice and is updated regularly. > So, instead of creating a new driver for the STM32 family, we decided to > use Rockchip’s in our own drm/stm directory and replace the > Rockchip-specific PHY by the STM32. Sure, it looks OK. Archit, any advices here ? > Comments are welcome :-) > Many thanks, > Philippe Thanks, Neil > > On 05/15/2017 10:22 AM, Neil Armstrong wrote: >> On 05/12/2017 04:56 PM, Philippe CORNU wrote: >>> This mipi dsi host driver is based on the Rockchip version of the >>> Synopsys Designware mipi dsi driver (rockchip/dw-mipi-dsi.c) >>> modified for the stm32 family: >>> - replace Rockchip digital & phy specific extensions with stm32's ones. >>> - add a bridge >>> >>> Signed-off-by: Philippe CORNU <philippe.cornu@xxxxxx> >>> --- >>> drivers/gpu/drm/stm/Kconfig | 7 + >>> drivers/gpu/drm/stm/Makefile | 2 + >>> drivers/gpu/drm/stm/dw-mipi-dsi.c | 1197 +++++++++++++++++++++++++++++++++++++ >>> 3 files changed, 1206 insertions(+) >>> create mode 100644 drivers/gpu/drm/stm/dw-mipi-dsi.c >>> >>> diff --git a/drivers/gpu/drm/stm/Kconfig b/drivers/gpu/drm/stm/Kconfig >>> index 2c4817f..0007789 100644 >>> --- a/drivers/gpu/drm/stm/Kconfig >>> +++ b/drivers/gpu/drm/stm/Kconfig >>> @@ -14,3 +14,10 @@ config DRM_STM >>> STMicroelectronics STM32 MCUs. >>> To compile this driver as a module, choose M here: the module >>> will be called stm-drm. >>> + >>> +config DRM_STM_DSI >>> + tristate "MIPI DSI support for STMicroelectronics SoC" >>> + depends on DRM_STM >>> + select DRM_MIPI_DSI >>> + help >>> + Choose this option for MIPI DSI support on STMicroelectronics SoC. >>> diff --git a/drivers/gpu/drm/stm/Makefile b/drivers/gpu/drm/stm/Makefile >>> index e114d45..e448a93 100644 >>> --- a/drivers/gpu/drm/stm/Makefile >>> +++ b/drivers/gpu/drm/stm/Makefile >>> @@ -4,4 +4,6 @@ stm-drm-y := \ >>> drv.o \ >>> ltdc.o >>> >>> +obj-$(CONFIG_DRM_STM_DSI) += dw-mipi-dsi.o >>> + >>> obj-$(CONFIG_DRM_STM) += stm-drm.o >>> diff --git a/drivers/gpu/drm/stm/dw-mipi-dsi.c b/drivers/gpu/drm/stm/dw-mipi-dsi.c >>> new file mode 100644 >>> index 0000000..4b7f7b9 >>> --- /dev/null >>> +++ b/drivers/gpu/drm/stm/dw-mipi-dsi.c >> >> >> Hi Philippe, >> >> First question, why couldn't this be transformed as a bridge driver along the Synopsys DW-HDMI driver ? >> >> Neil >> > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
