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[v2,1/2] dt-bindings: display: bridge: Add documentation for SN65DSI84

Message ID 20210203071256.42050-1-jagan@amarulasolutions.com
State New
Headers show
Series [v2,1/2] dt-bindings: display: bridge: Add documentation for SN65DSI84 | expand

Commit Message

Jagan Teki Feb. 3, 2021, 7:12 a.m. UTC 
SN65DSI84 is a Single Channel DSI to Dual-link LVDS bridge from
Texas Instruments.

SN65DSI83, SN65DSI85 are variants of the same family of bridge
controllers.

Right now the bridge driver is supporting a single link, dual-link
support requires to initiate I2C Channel B registers, so dt-bindings
documented with single link LVDS.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
---
Changes for v2:
- none

 .../bindings/display/bridge/ti,sn65dsi84.yaml | 127 ++++++++++++++++++
 1 file changed, 127 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/display/bridge/ti,sn65dsi84.yaml

Comments

Rob Herring Feb. 4, 2021, 5:40 p.m. UTC | #1 
On Wed, Feb 03, 2021 at 12:42:55PM +0530, Jagan Teki wrote:
> SN65DSI84 is a Single Channel DSI to Dual-link LVDS bridge from
> Texas Instruments.
> 
> SN65DSI83, SN65DSI85 are variants of the same family of bridge
> controllers.
> 
> Right now the bridge driver is supporting a single link, dual-link
> support requires to initiate I2C Channel B registers, so dt-bindings
> documented with single link LVDS.
> 
> Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
> ---
> Changes for v2:
> - none
> 
>  .../bindings/display/bridge/ti,sn65dsi84.yaml | 127 ++++++++++++++++++
>  1 file changed, 127 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/display/bridge/ti,sn65dsi84.yaml
> 
> diff --git a/Documentation/devicetree/bindings/display/bridge/ti,sn65dsi84.yaml b/Documentation/devicetree/bindings/display/bridge/ti,sn65dsi84.yaml
> new file mode 100644
> index 000000000000..891382a76c1a
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/display/bridge/ti,sn65dsi84.yaml
> @@ -0,0 +1,127 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/display/bridge/ti,sn65dsi84.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: TI SN65DSI84 MIPI DSI to LVDS bridge bindings
> +
> +maintainers:
> +  - Jagan Teki <jagan@amarulasolutions.com>
> +
> +description: |
> +  The SN65DSI84 DSI to FlatLink bridge features a single channel MIPI D-PHY receiver
> +  front-end configuration with 4 lanes per channel operating at 1 Gbps per lanes.
> +  The bridge decodes MIPI DSI 18bpp RGB666 and 240bpp RG888 packets and converts
> +  the formatted video data stream to a FlatLink compatible LVDS output operating
> +  at pixel clocks operating from 25 MHx to 154 MHz, offering a Dual-Link LVDS,
> +  Single-Link LVDS interface with four data lanes per link.
> +
> +  https://www.ti.com/product/SN65DSI84
> +
> +properties:
> +  compatible:
> +    const: ti,sn65dsi84
> +
> +  reg:
> +    maxItems: 1
> +    description: i2c address of the bridge, 0x2c

Just 'const: 0x2c' if that's the only valid address.

> +
> +  enable-gpios:
> +    maxItems: 1
> +    description: GPIO specifier for bridge enable pin (active high).
> +
> +  ports:
> +    type: object
> +    description:
> +      A node containing input and output port nodes with endpoint definitions
> +      as documented in
> +      Documentation/devicetree/bindings/media/video-interfaces.txt
> +    properties:
> +      "#address-cells":
> +        const: 1
> +
> +      "#size-cells":
> +        const: 0
> +
> +      port@0:
> +        type: object
> +        description: |
> +          DSI Input. The remote endpoint phandle should be a
> +          reference to a valid mipi_dsi_host device node.
> +
> +      port@1:
> +        type: object
> +        description: |
> +          Video port for LVDS output (panel or connector).

This needs to use the graph.yaml schema. See the ones in drm-misc-next 
that are already converted.

> +
> +    required:
> +      - port@0
> +      - port@1
> +
> +required:
> +  - compatible
> +  - reg
> +  - enable-gpios
> +  - ports
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/gpio/gpio.h>
> +
> +    dsi {
> +       #address-cells = <1>;
> +       #size-cells = <0>;
> +
> +       ports {
> +           #address-cells = <1>;
> +           #size-cells = <0>;
> +
> +           port@0 {
> +               reg = <0>;
> +               dsi_in: endpoint {
> +                   remote-endpoint = <&ltdc_ep0_out>;
> +               };
> +           };
> +
> +           port@1 {
> +               reg = <1>;
> +               dsi_out: endpoint {
> +                   remote-endpoint = <&bridge_in>;
> +                   data-lanes = <0 1>;
> +               };
> +           };
> +       };
> +    };
> +
> +    i2c6 {
> +       #address-cells = <1>;
> +       #size-cells = <0>;
> +
> +       bridge@2c {
> +           compatible = "ti,sn65dsi84";
> +           reg = <0x2c>;
> +           enable-gpios = <&gpiof 15 GPIO_ACTIVE_HIGH>;
> +
> +           ports {
> +               #address-cells = <1>;
> +               #size-cells = <0>;
> +
> +               port@0 {
> +                   reg = <0>;
> +                   bridge_in: endpoint {
> +                        remote-endpoint = <&dsi_out>;
> +                   };
> +               };
> +
> +               port@1 {
> +                   reg = <1>;
> +                   bridge_out: endpoint {
> +                        remote-endpoint = <&panel_in_lvds>;
> +                   };
> +               };
> +           };
> +       };
> +    };
> -- 
> 2.25.1
>
Jagan Teki Feb. 4, 2021, 9:15 p.m. UTC | #2 
On Wed, Feb 3, 2021 at 2:51 PM Michael Nazzareno Trimarchi
<michael@amarulasolutions.com> wrote:
>
> Hi
>
> On Wed, Feb 3, 2021 at 8:13 AM Jagan Teki <jagan@amarulasolutions.com> wrote:
> >
> > SN65DSI84 is a Single Channel DSI to Dual-link LVDS bridge from
> > Texas Instruments.
> >
> > SN65DSI83, SN65DSI85 are variants of the same family of bridge
> > controllers.
> >
> > Right now the bridge driver is supporting a single link, dual-link
> > support requires to initiate I2C Channel B registers.
> >
> > Tested with STM32MP1 MIPI DSI host design configuration.
> >
> > Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
> > ---
> > Changes for v2:
> > - dropped the mdelays between commands as delays in init script in
> >   datasheet is based Aardvark I2C host adaptor.
> >   https://e2e.ti.com/support/interface/f/138/t/974276
> >
> >  MAINTAINERS                           |   6 +
> >  drivers/gpu/drm/bridge/Kconfig        |  19 ++
> >  drivers/gpu/drm/bridge/Makefile       |   1 +
> >  drivers/gpu/drm/bridge/ti-sn65dsi84.c | 457 ++++++++++++++++++++++++++
> >  4 files changed, 483 insertions(+)
> >  create mode 100644 drivers/gpu/drm/bridge/ti-sn65dsi84.c
> >
> > diff --git a/MAINTAINERS b/MAINTAINERS
> > index 12dd1fff2a39..44750ff7640c 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -5984,6 +5984,12 @@ S:       Maintained
> >  F:     Documentation/devicetree/bindings/display/ti/
> >  F:     drivers/gpu/drm/omapdrm/
> >
> > +DRM DRIVERS FOR TI SN65DSI84 DSI TO LVDS BRIDGE
> > +M:     Jagan Teki <jagan@amarulasolutions.com>
> > +S:     Maintained
> > +F:     Documentation/devicetree/bindings/display/bridge/ti,sn65dsi84.yaml
> > +F:     drivers/gpu/drm/bridge/ti-sn65dsi84.c
> > +
> >  DRM DRIVERS FOR V3D
> >  M:     Eric Anholt <eric@anholt.net>
> >  S:     Supported
> > diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
> > index e4110d6ca7b3..6494881bffb3 100644
> > --- a/drivers/gpu/drm/bridge/Kconfig
> > +++ b/drivers/gpu/drm/bridge/Kconfig
> > @@ -232,6 +232,25 @@ config DRM_TI_TFP410
> >         help
> >           Texas Instruments TFP410 DVI/HDMI Transmitter driver
> >
> > +config DRM_TI_SN65DSI84
> > +       tristate "TI SN65DSI84 DSI to LVDS bridge"
> > +       depends on OF
> > +       select DRM_KMS_HELPER
> > +       select REGMAP_I2C
> > +       select DRM_PANEL
> > +       select DRM_MIPI_DSI
> > +       help
> > +         Texas Instruments SN65DSI84 Single Channel DSI to Dual-link LVDS
> > +         bridge driver.
> > +
> > +         Bridge decodes MIPI DSI 18bpp RGB666 and 240bpp RG888 packets and
> > +         converts the formatted video data stream to a FlatLink compatible
> > +         LVDS output operating at pixel clocks operating from 25 MHx to
> > +         154 MHz.
> > +
> > +         SN65DSI84 offers a Dual-Link LVDS, Single-Link LVDS interface with
> > +         four data lanes per link.
> > +
> >  config DRM_TI_SN65DSI86
> >         tristate "TI SN65DSI86 DSI to eDP bridge"
> >         depends on OF
> > diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
> > index 86e7acc76f8d..3906052ef639 100644
> > --- a/drivers/gpu/drm/bridge/Makefile
> > +++ b/drivers/gpu/drm/bridge/Makefile
> > @@ -20,6 +20,7 @@ obj-$(CONFIG_DRM_TOSHIBA_TC358767) += tc358767.o
> >  obj-$(CONFIG_DRM_TOSHIBA_TC358768) += tc358768.o
> >  obj-$(CONFIG_DRM_TOSHIBA_TC358775) += tc358775.o
> >  obj-$(CONFIG_DRM_I2C_ADV7511) += adv7511/
> > +obj-$(CONFIG_DRM_TI_SN65DSI84) += ti-sn65dsi84.o
> >  obj-$(CONFIG_DRM_TI_SN65DSI86) += ti-sn65dsi86.o
> >  obj-$(CONFIG_DRM_TI_TFP410) += ti-tfp410.o
> >  obj-$(CONFIG_DRM_TI_TPD12S015) += ti-tpd12s015.o
> > diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi84.c b/drivers/gpu/drm/bridge/ti-sn65dsi84.c
> > new file mode 100644
> > index 000000000000..27a9074db17e
> > --- /dev/null
> > +++ b/drivers/gpu/drm/bridge/ti-sn65dsi84.c
> > @@ -0,0 +1,457 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Copyright (c) 2021 Engicam srl
> > + * Copyright (C) 2021 Amarula Solutions(India)
> > + * Author: Jagan Teki <jagan@amarulasolutions.com>
> > + */
> > +
> > +#include <drm/drm_of.h>
> > +#include <drm/drm_panel.h>
> > +#include <drm/drm_print.h>
> > +#include <drm/drm_mipi_dsi.h>
> > +
> > +#include <linux/delay.h>
> > +#include <linux/gpio/consumer.h>
> > +#include <linux/i2c.h>
> > +#include <linux/module.h>
> > +#include <linux/regmap.h>
> > +
> > +/* sn65dsi84 registers */
> > +#define SN65DSI_SOFT_RESET             0x09
> > +#define SN65DSI_LVDS_CLK               0x0a
> > +#define SN65DSI_CLK_DIV                        0x0b
> > +#define SN65DSI_CLK_PLL                        0x0d
> > +#define SN65DSI_DSI_CFG                        0x10
> > +#define SN65DSI_DSI_CLK_EQ             0x11
> > +#define SN65DSI_DSI_CLK_RANGE          0x12
> > +#define SN65DSI_LVDS_MODE              0x18
> > +#define SN65DSI_CHA_LINE_LO            0x20
> > +#define SN65DSI_CHA_LINE_HI            0x21
> > +#define SN65DSI_CHA_VIRT_LO            0x24
> > +#define SN65DSI_CHA_VIRT_HI            0x25
> > +#define SN65DSI_CHA_SYNC_DELAY_LO      0x28
> > +#define SN65DSI_CHA_SYNC_DELAY_HI      0x29
> > +#define SN65DSI_CHA_HSYNC_WIDTH_LO     0x2c
> > +#define SN65DSI_CHA_HSYNC_WIDTH_HI     0x2d
> > +#define SN65DSI_CHA_VSYNC_WIDTH_LO     0x30
> > +#define SN65DSI_CHA_VSYNC_WIDTH_HI     0x31
> > +#define SN65DSI_CHA_HBACK_PORCH                0x34
> > +#define SN65DSI_CHA_VBACK_PORCH                0x36
> > +#define SN65DSI_CHA_HFRONT_PORCH       0x38
> > +#define SN65DSI_CHA_VFRONT_PORCH       0x3a
> > +#define SN65DSI_CHA_ERR                        0xe5
> > +
> > +/* sn65dsi register bits */
> > +#define SN65DSI_RESET_EN               BIT(0)
> > +#define SN65DSI_PLL_EN                 BIT(0)
> > +#define SN65DSI_LVDS_CLK_MASK          GENMASK(3, 1)
> > +#define SN65DSI_LVDS_CLK_SHIFT         1
> > +#define SN65DSI_LVDS_CLK_SRC_DSI       BIT(0)
> > +#define SN65DSI_CLK_DIV_MASK           GENMASK(7, 3)
> > +#define SN65DSI_CLK_DIV_SHIFT          3
> > +#define SN65DSI_DSI_LANE_MASK          GENMASK(4, 3)
> > +#define SN65DSI_DSI_LANE_SHIFT         3
> > +#define SN65DSI_LVDS_LINK_CFG          BIT(4)
> > +#define SN65DSI_LVDS_CHA_24BPP         BIT(3)
> > +#define SN65DSI_CHA_LOW_SYNC_DELAY     0x20
> > +#define SN65DSI_CHA_HIGH_SYNC_DELAY    0x00
> > +
> > +struct sn65dsi {
> > +       struct device                   *dev;
> > +       struct drm_bridge               bridge;
> > +       struct drm_bridge               *panel_bridge;
> > +
> > +       struct device_node              *host_node;
> > +       struct mipi_dsi_device          *dsi;
> > +       u8                              dsi_lanes;
> > +
> > +       struct regmap                   *regmap;
> > +       struct gpio_desc                *enable;
> > +};
>
> I suggest a better name. 3 different families are compatible here

sn65dsi83/84/85 are similar chips. Do you mean ti-sn65dsi8x.c it can
confuse with exiting ti-sn65dsi86.c, doesn't it?

> > +
> > +static const struct regmap_config sn65dsi_regmap_config = {
> > +       .reg_bits = 8,
> > +       .val_bits = 8,
> > +       .max_register = SN65DSI_CHA_ERR,
> > +       .name = "sn65dsi",
> > +       .cache_type = REGCACHE_RBTREE,
> > +};
> > +
> > +static inline struct sn65dsi *bridge_to_sn65dsi(struct drm_bridge *bridge)
> > +{
> > +       return container_of(bridge, struct sn65dsi, bridge);
> > +}
> > +
> > +static struct drm_display_mode *bridge_to_mode(struct drm_bridge *bridge)
> > +{
> > +       return &bridge->encoder->crtc->state->mode;
> > +}
> > +
> > +static void sn65dsi_setup_channels(struct sn65dsi *sn,
> > +                                  struct drm_display_mode *mode)
> > +{
> > +       u32 hsync_len, hfront_porch, hback_porch;
> > +       u32 vsync_len, vfront_porch, vback_porch;
> > +
> > +       hfront_porch = mode->hsync_start - mode->hdisplay;
> > +       hsync_len = mode->hsync_end - mode->hsync_start;
> > +       hback_porch = mode->htotal - mode->hsync_end;
> > +
> > +       vfront_porch = mode->vsync_start - mode->vdisplay;
> > +       vsync_len = mode->vsync_end - mode->vsync_start;
> > +       vback_porch = mode->vtotal - mode->vsync_end;
> > +
> > +       /* cha, lower 8-bits of hdisplay */
> > +       regmap_write(sn->regmap, SN65DSI_CHA_LINE_LO, mode->hdisplay & 0xff);
> > +
> > +       /* cha, upper 4-bits of hdisplay */
> > +       regmap_write(sn->regmap, SN65DSI_CHA_LINE_HI, (mode->hdisplay >> 8) & 0xff);
> > +
> > +       /* cha, lower 8-bits of vdisplay */
> > +       regmap_write(sn->regmap, SN65DSI_CHA_VIRT_LO, mode->vdisplay & 0xff);
> > +
> > +       /* cha, upper 4-bits of vdisplay */
> > +       regmap_write(sn->regmap, SN65DSI_CHA_VIRT_HI, (mode->vdisplay >> 8) & 0xff);
> > +
> > +       /*cha, lower sync delay */
> > +       regmap_write(sn->regmap, SN65DSI_CHA_SYNC_DELAY_LO, SN65DSI_CHA_LOW_SYNC_DELAY);
> > +
> > +       /*cha, upper sync delay */
> > +       regmap_write(sn->regmap, SN65DSI_CHA_SYNC_DELAY_HI, SN65DSI_CHA_HIGH_SYNC_DELAY);
> > +
> > +       /* cha, lower 8-bits of hsync_len */
> > +       regmap_write(sn->regmap, SN65DSI_CHA_HSYNC_WIDTH_LO, hsync_len & 0xff);
> > +
> > +       /* cha, upper 2-bits of hsync_len */
> > +       regmap_write(sn->regmap, SN65DSI_CHA_HSYNC_WIDTH_HI, (hsync_len >> 8) & 0xff);
> > +
> > +       /* cha, lower 8-bits of vsync_len */
> > +       regmap_write(sn->regmap, SN65DSI_CHA_VSYNC_WIDTH_LO, vsync_len & 0xff);
> > +
> > +       /* cha, upper 2-bits of vsync_len */
> > +       regmap_write(sn->regmap, SN65DSI_CHA_VSYNC_WIDTH_HI, (vsync_len >> 8) & 0xff);
> > +
> > +       /* cha, hback_porch */
> > +       regmap_write(sn->regmap, SN65DSI_CHA_HBACK_PORCH, hback_porch & 0xff);
> > +
> > +       /* cha, vback_porch */
> > +       regmap_write(sn->regmap, SN65DSI_CHA_VBACK_PORCH, vback_porch & 0xff);
> > +
> > +       /* cha, hfront_porch */
> > +       regmap_write(sn->regmap, SN65DSI_CHA_HFRONT_PORCH, hfront_porch & 0xff);
> > +
> > +       /* cha, vfront_porch */
> > +       regmap_write(sn->regmap, SN65DSI_CHA_VFRONT_PORCH, vfront_porch & 0xff);
> > +}
> > +
> > +static int sn65dsi_get_clk_range(int min, int max, unsigned long clock,
> > +                                unsigned long start, unsigned long diff)
> > +{
> > +       unsigned long next;
> > +       int i;
> > +
> > +       for (i = min; i <= max; i++) {
> > +               next = start + diff;
> > +               if (start <= clock && clock < next)
> > +                       return i;
> > +
> > +               start += diff;
> > +       }
> > +
> > +       return -EINVAL;
> > +}
> > +
> > +static void sn65dsi_enable(struct drm_bridge *bridge)
> > +{
> > +       struct sn65dsi *sn = bridge_to_sn65dsi(bridge);
> > +       struct drm_display_mode *mode = bridge_to_mode(bridge);
> > +       int bpp = mipi_dsi_pixel_format_to_bpp(sn->dsi->format);
> > +       unsigned int lanes = sn->dsi->lanes;
> > +       unsigned int pixel_clk = mode->clock * 1000;
> > +       unsigned int dsi_clk = pixel_clk * bpp / (lanes * 2);
> > +       unsigned int val;
> > +
> > +       /* reset SOFT_RESET bit */
> > +       regmap_write(sn->regmap, SN65DSI_SOFT_RESET, 0x0);
> > +
> > +       msleep(10);
> > +
> > +       /* reset PLL_EN bit */
> > +       regmap_write(sn->regmap, SN65DSI_CLK_PLL, 0x0);
> > +
> > +       msleep(10);
> > +
> > +       /* setup lvds clock */
> > +       val = sn65dsi_get_clk_range(0, 5, pixel_clk, 25000000, 25000000);
> > +       if (val < 0) {
> > +               DRM_DEV_ERROR(sn->dev, "invalid LVDS clock range %d\n", val);
> > +               return;
> > +       }
> > +
> > +       regmap_update_bits(sn->regmap, SN65DSI_LVDS_CLK,
> > +                          SN65DSI_LVDS_CLK_MASK,
> > +                          val << SN65DSI_LVDS_CLK_SHIFT);
> > +
> > +       regmap_update_bits(sn->regmap, SN65DSI_LVDS_CLK,
> > +                          SN65DSI_LVDS_CLK_SRC_DSI,
> > +                          SN65DSI_LVDS_CLK_SRC_DSI);
> > +
> > +       /* setup bridge clock divider */
> > +       val = (dsi_clk / pixel_clk) - 1;
> > +       regmap_update_bits(sn->regmap, SN65DSI_CLK_DIV,
> > +                          SN65DSI_CLK_DIV_MASK,
> > +                          val << SN65DSI_CLK_DIV_SHIFT);
> > +
> > +       /* configure dsi */
> > +       regmap_update_bits(sn->regmap, SN65DSI_DSI_CFG,
> > +                          SN65DSI_DSI_LANE_MASK,
> > +                          lanes << SN65DSI_DSI_LANE_SHIFT);
> > +
> > +       /* dsi clock range */
> > +       val = sn65dsi_get_clk_range(8, 100, dsi_clk, 40000000, 5000000);
> > +       if (val < 0) {
> > +               DRM_DEV_ERROR(sn->dev, "invalid DSI clock range %d\n", val);
> > +               return;
> > +       }
> > +
> > +       regmap_write(sn->regmap, SN65DSI_DSI_CLK_RANGE, val);
> > +
> > +       /* setup lvds channels */
> > +       regmap_read(sn->regmap, SN65DSI_LVDS_MODE, &val);
> > +       if (bpp == 24)
> > +               val |= SN65DSI_LVDS_CHA_24BPP;
> > +       regmap_write(sn->regmap, SN65DSI_LVDS_MODE, val);
>
> This register should have even how data are packed by dsi. There are two mode
> mode 1 and mode 2.

You mean BIT:3, 2 CHA_24BPP_MODE, CHB_24BPP_MODE?

The above SN64DSI_LVDS_CHA_24BPP is the same and it is updating CHA
for now as CHB is not supported yet.

>
> > +
> > +       /* TODO Channel B required to set up for dual-link LVDS */
> > +       sn65dsi_setup_channels(sn, mode);
> > +
> > +       /* set SOFT_RESET bit */
> > +       regmap_write(sn->regmap, SN65DSI_SOFT_RESET, SN65DSI_RESET_EN);
> > +
> > +       msleep(10);
> > +
> > +       /* set PLL_EN bit */
> > +       regmap_write(sn->regmap, SN65DSI_CLK_PLL, SN65DSI_PLL_EN);
> > +
> > +       msleep(10);
> > +}
> > +
> > +static void sn65dsi_disable(struct drm_bridge *bridge)
> > +{
> > +       struct sn65dsi *sn = bridge_to_sn65dsi(bridge);
> > +
> > +       /* set PLL_EN bit */
> > +       regmap_write(sn->regmap, SN65DSI_CLK_PLL, 0x0);
> > +
> > +       msleep(10);
> > +
> > +       /* set SOFT_RESET bit */
> > +       regmap_write(sn->regmap, SN65DSI_SOFT_RESET, 0x0);
> > +
> > +       msleep(10);
>
> Can you point me out the documenation where is written

I can see the sequence pointed in 7.4.3 Initialization Sequence

>
> > +}
> > +
> > +static void sn65dsi_post_disable(struct drm_bridge *bridge)
> > +{
> > +       struct sn65dsi *sn = bridge_to_sn65dsi(bridge);
> > +
> > +       gpiod_set_value_cansleep(sn->enable, 1);
> > +
> > +       msleep(10);
> > +
> > +       gpiod_set_value_cansleep(sn->enable, 0);
> > +
> > +       msleep(10);
>
> Again is there any description about the reset time in datasheet. If
> so, please point to the section
>
> > +}
> > +
> > +static void sn65dsi_pre_enable(struct drm_bridge *bridge)
> > +{
> > +       struct sn65dsi *sn = bridge_to_sn65dsi(bridge);
> > +
> > +       gpiod_set_value_cansleep(sn->enable, 0);
> > +
> > +       msleep(10);
> > +
> > +       gpiod_set_value_cansleep(sn->enable, 1);
> > +
> > +       msleep(10);
>
> Ditto
>
> > +}
> > +
> > +static int sn65dsi_attach(struct drm_bridge *bridge, enum drm_bridge_attach_flags flags)
> > +{
> > +       struct sn65dsi *sn = bridge_to_sn65dsi(bridge);
> > +       struct mipi_dsi_host *host;
> > +       struct mipi_dsi_device *dsi;
> > +       const struct mipi_dsi_device_info info = { .type = "sn65dsi",
> > +                                                  .channel = 0,
> > +                                                  .node = NULL,
> > +                                                };
> > +       int ret;
> > +
> > +       host = of_find_mipi_dsi_host_by_node(sn->host_node);
> > +       if (!host) {
> > +               DRM_DEV_ERROR(sn->dev, "failed to find dsi host\n");
> > +               return -EPROBE_DEFER;
> > +       }
> > +
> > +       dsi = mipi_dsi_device_register_full(host, &info);
> > +       if (IS_ERR(dsi)) {
> > +               DRM_DEV_ERROR(sn->dev, "failed to create dsi device\n");
> > +               return PTR_ERR(sn->dsi);
> > +       }
> > +
> > +       sn->dsi = dsi;
> > +       dsi->lanes = sn->dsi_lanes;
> > +       dsi->format = MIPI_DSI_FMT_RGB888;
> > +       dsi->mode_flags = MIPI_DSI_MODE_VIDEO;
> > +
> > +       ret = mipi_dsi_attach(dsi);
> > +       if (ret) {
> > +               DRM_DEV_ERROR(sn->dev, "failed to attach dsi host\n");
> > +               goto err_dsi_attach;
> > +       }
> > +
> > +       return drm_bridge_attach(bridge->encoder, sn->panel_bridge,
> > +                                &sn->bridge, flags);
> > +
> > +err_dsi_attach:
> > +       mipi_dsi_device_unregister(dsi);
> > +       return ret;
> > +}
> > +
> > +static const struct drm_bridge_funcs sn65dsi_bridge_funcs = {
> > +       .attach         = sn65dsi_attach,
> > +       .pre_enable     = sn65dsi_pre_enable,
> > +       .enable         = sn65dsi_enable,
> > +       .disable        = sn65dsi_disable,
> > +       .post_disable   = sn65dsi_post_disable,
> > +};
> > +
> > +static int sn65dsi_parse_dt(struct sn65dsi *sn)
> > +{
> > +       struct device *dev = sn->dev;
> > +       struct device_node *endpoint, *parent;
> > +       struct property *prop;
> > +       struct drm_panel *panel;
> > +       int len = 0;
> > +       int ret;
> > +
> > +       sn->enable = devm_gpiod_get(dev, "enable", GPIOD_OUT_LOW);
> > +       if (IS_ERR(sn->enable)) {
> > +               DRM_DEV_ERROR(dev, "failed to get enable gpio\n");
> > +               return PTR_ERR(sn->enable);
> > +       }
> > +
> > +       ret = drm_of_find_panel_or_bridge(dev->of_node, 1, 0, &panel, NULL);
> > +       if (ret < 0)
> > +               return ret;
> > +       if (!panel)
> > +               return -ENODEV;
> > +
> > +       sn->panel_bridge = devm_drm_panel_bridge_add(dev, panel);
> > +       if (IS_ERR(sn->panel_bridge))
> > +               return PTR_ERR(sn->panel_bridge);
> > +
> > +       /*
> > +        * To get the data-lanes of dsi, we need to access the port1 of dsi_out
> > +        * from the port0 of bridge.
> > +        */
> > +       endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 0, -1);
> > +       if (endpoint) {
>
> What is happen if you have no endpoint should not already fail?

You mean for !endpoint case? it would return -EINVAL. the next lanes
cases would return for no endpoint cases.

Jagan.
Laurent Pinchart Feb. 4, 2021, 10:29 p.m. UTC | #3 
Hi Jagan,

Thank you for the patch.

On Wed, Feb 03, 2021 at 12:42:56PM +0530, Jagan Teki wrote:
> SN65DSI84 is a Single Channel DSI to Dual-link LVDS bridge from
> Texas Instruments.
> 
> SN65DSI83, SN65DSI85 are variants of the same family of bridge
> controllers.
> 
> Right now the bridge driver is supporting a single link, dual-link
> support requires to initiate I2C Channel B registers.

MArek Vasut (on CC) has very recently posted a driver for the SN65DSI86.
Should the two drivers be merged together ?

> Tested with STM32MP1 MIPI DSI host design configuration.
> 
> Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
> ---
> Changes for v2:
> - dropped the mdelays between commands as delays in init script in
>   datasheet is based Aardvark I2C host adaptor.
>   https://e2e.ti.com/support/interface/f/138/t/974276
> 
>  MAINTAINERS                           |   6 +
>  drivers/gpu/drm/bridge/Kconfig        |  19 ++
>  drivers/gpu/drm/bridge/Makefile       |   1 +
>  drivers/gpu/drm/bridge/ti-sn65dsi84.c | 457 ++++++++++++++++++++++++++
>  4 files changed, 483 insertions(+)
>  create mode 100644 drivers/gpu/drm/bridge/ti-sn65dsi84.c
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 12dd1fff2a39..44750ff7640c 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -5984,6 +5984,12 @@ S:	Maintained
>  F:	Documentation/devicetree/bindings/display/ti/
>  F:	drivers/gpu/drm/omapdrm/
>  
> +DRM DRIVERS FOR TI SN65DSI84 DSI TO LVDS BRIDGE
> +M:	Jagan Teki <jagan@amarulasolutions.com>
> +S:	Maintained
> +F:	Documentation/devicetree/bindings/display/bridge/ti,sn65dsi84.yaml
> +F:	drivers/gpu/drm/bridge/ti-sn65dsi84.c
> +
>  DRM DRIVERS FOR V3D
>  M:	Eric Anholt <eric@anholt.net>
>  S:	Supported
> diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
> index e4110d6ca7b3..6494881bffb3 100644
> --- a/drivers/gpu/drm/bridge/Kconfig
> +++ b/drivers/gpu/drm/bridge/Kconfig
> @@ -232,6 +232,25 @@ config DRM_TI_TFP410
>  	help
>  	  Texas Instruments TFP410 DVI/HDMI Transmitter driver
>  
> +config DRM_TI_SN65DSI84
> +	tristate "TI SN65DSI84 DSI to LVDS bridge"
> +	depends on OF
> +	select DRM_KMS_HELPER
> +	select REGMAP_I2C
> +	select DRM_PANEL
> +	select DRM_MIPI_DSI
> +	help
> +	  Texas Instruments SN65DSI84 Single Channel DSI to Dual-link LVDS
> +	  bridge driver.
> +
> +	  Bridge decodes MIPI DSI 18bpp RGB666 and 240bpp RG888 packets and
> +	  converts the formatted video data stream to a FlatLink compatible
> +	  LVDS output operating at pixel clocks operating from 25 MHx to
> +	  154 MHz.
> +
> +	  SN65DSI84 offers a Dual-Link LVDS, Single-Link LVDS interface with
> +	  four data lanes per link.
> +
>  config DRM_TI_SN65DSI86
>  	tristate "TI SN65DSI86 DSI to eDP bridge"
>  	depends on OF
> diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
> index 86e7acc76f8d..3906052ef639 100644
> --- a/drivers/gpu/drm/bridge/Makefile
> +++ b/drivers/gpu/drm/bridge/Makefile
> @@ -20,6 +20,7 @@ obj-$(CONFIG_DRM_TOSHIBA_TC358767) += tc358767.o
>  obj-$(CONFIG_DRM_TOSHIBA_TC358768) += tc358768.o
>  obj-$(CONFIG_DRM_TOSHIBA_TC358775) += tc358775.o
>  obj-$(CONFIG_DRM_I2C_ADV7511) += adv7511/
> +obj-$(CONFIG_DRM_TI_SN65DSI84) += ti-sn65dsi84.o
>  obj-$(CONFIG_DRM_TI_SN65DSI86) += ti-sn65dsi86.o
>  obj-$(CONFIG_DRM_TI_TFP410) += ti-tfp410.o
>  obj-$(CONFIG_DRM_TI_TPD12S015) += ti-tpd12s015.o
> diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi84.c b/drivers/gpu/drm/bridge/ti-sn65dsi84.c
> new file mode 100644
> index 000000000000..27a9074db17e
> --- /dev/null
> +++ b/drivers/gpu/drm/bridge/ti-sn65dsi84.c
> @@ -0,0 +1,457 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (c) 2021 Engicam srl
> + * Copyright (C) 2021 Amarula Solutions(India)
> + * Author: Jagan Teki <jagan@amarulasolutions.com>
> + */
> +
> +#include <drm/drm_of.h>
> +#include <drm/drm_panel.h>
> +#include <drm/drm_print.h>
> +#include <drm/drm_mipi_dsi.h>
> +
> +#include <linux/delay.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/i2c.h>
> +#include <linux/module.h>
> +#include <linux/regmap.h>
> +
> +/* sn65dsi84 registers */
> +#define SN65DSI_SOFT_RESET		0x09
> +#define SN65DSI_LVDS_CLK		0x0a
> +#define SN65DSI_CLK_DIV			0x0b
> +#define SN65DSI_CLK_PLL			0x0d
> +#define SN65DSI_DSI_CFG			0x10
> +#define SN65DSI_DSI_CLK_EQ		0x11
> +#define SN65DSI_DSI_CLK_RANGE		0x12
> +#define SN65DSI_LVDS_MODE		0x18
> +#define SN65DSI_CHA_LINE_LO		0x20
> +#define SN65DSI_CHA_LINE_HI		0x21
> +#define SN65DSI_CHA_VIRT_LO		0x24
> +#define SN65DSI_CHA_VIRT_HI		0x25
> +#define SN65DSI_CHA_SYNC_DELAY_LO	0x28
> +#define SN65DSI_CHA_SYNC_DELAY_HI	0x29
> +#define SN65DSI_CHA_HSYNC_WIDTH_LO	0x2c
> +#define SN65DSI_CHA_HSYNC_WIDTH_HI	0x2d
> +#define SN65DSI_CHA_VSYNC_WIDTH_LO	0x30
> +#define SN65DSI_CHA_VSYNC_WIDTH_HI	0x31
> +#define SN65DSI_CHA_HBACK_PORCH		0x34
> +#define SN65DSI_CHA_VBACK_PORCH		0x36
> +#define SN65DSI_CHA_HFRONT_PORCH	0x38
> +#define SN65DSI_CHA_VFRONT_PORCH	0x3a
> +#define SN65DSI_CHA_ERR			0xe5
> +
> +/* sn65dsi register bits */
> +#define SN65DSI_RESET_EN		BIT(0)
> +#define SN65DSI_PLL_EN			BIT(0)
> +#define SN65DSI_LVDS_CLK_MASK		GENMASK(3, 1)
> +#define SN65DSI_LVDS_CLK_SHIFT		1
> +#define SN65DSI_LVDS_CLK_SRC_DSI	BIT(0)
> +#define SN65DSI_CLK_DIV_MASK		GENMASK(7, 3)
> +#define SN65DSI_CLK_DIV_SHIFT		3
> +#define SN65DSI_DSI_LANE_MASK		GENMASK(4, 3)
> +#define SN65DSI_DSI_LANE_SHIFT		3
> +#define SN65DSI_LVDS_LINK_CFG		BIT(4)
> +#define SN65DSI_LVDS_CHA_24BPP		BIT(3)
> +#define SN65DSI_CHA_LOW_SYNC_DELAY	0x20
> +#define SN65DSI_CHA_HIGH_SYNC_DELAY	0x00
> +
> +struct sn65dsi {
> +	struct device			*dev;
> +	struct drm_bridge		bridge;
> +	struct drm_bridge		*panel_bridge;
> +
> +	struct device_node		*host_node;
> +	struct mipi_dsi_device		*dsi;
> +	u8				dsi_lanes;
> +
> +	struct regmap			*regmap;
> +	struct gpio_desc		*enable;
> +};
> +
> +static const struct regmap_config sn65dsi_regmap_config = {
> +	.reg_bits = 8,
> +	.val_bits = 8,
> +	.max_register = SN65DSI_CHA_ERR,
> +	.name = "sn65dsi",
> +	.cache_type = REGCACHE_RBTREE,
> +};
> +
> +static inline struct sn65dsi *bridge_to_sn65dsi(struct drm_bridge *bridge)
> +{
> +	return container_of(bridge, struct sn65dsi, bridge);
> +}
> +
> +static struct drm_display_mode *bridge_to_mode(struct drm_bridge *bridge)
> +{
> +	return &bridge->encoder->crtc->state->mode;
> +}
> +
> +static void sn65dsi_setup_channels(struct sn65dsi *sn,
> +				   struct drm_display_mode *mode)
> +{
> +	u32 hsync_len, hfront_porch, hback_porch;
> +	u32 vsync_len, vfront_porch, vback_porch;
> +
> +	hfront_porch = mode->hsync_start - mode->hdisplay;
> +	hsync_len = mode->hsync_end - mode->hsync_start;
> +	hback_porch = mode->htotal - mode->hsync_end;
> +
> +	vfront_porch = mode->vsync_start - mode->vdisplay;
> +	vsync_len = mode->vsync_end - mode->vsync_start;
> +	vback_porch = mode->vtotal - mode->vsync_end;
> +
> +	/* cha, lower 8-bits of hdisplay */
> +	regmap_write(sn->regmap, SN65DSI_CHA_LINE_LO, mode->hdisplay & 0xff);
> +
> +	/* cha, upper 4-bits of hdisplay */
> +	regmap_write(sn->regmap, SN65DSI_CHA_LINE_HI, (mode->hdisplay >> 8) & 0xff);
> +
> +	/* cha, lower 8-bits of vdisplay */
> +	regmap_write(sn->regmap, SN65DSI_CHA_VIRT_LO, mode->vdisplay & 0xff);
> +
> +	/* cha, upper 4-bits of vdisplay */
> +	regmap_write(sn->regmap, SN65DSI_CHA_VIRT_HI, (mode->vdisplay >> 8) & 0xff);
> +
> +	/*cha, lower sync delay */
> +	regmap_write(sn->regmap, SN65DSI_CHA_SYNC_DELAY_LO, SN65DSI_CHA_LOW_SYNC_DELAY);
> +
> +	/*cha, upper sync delay */
> +	regmap_write(sn->regmap, SN65DSI_CHA_SYNC_DELAY_HI, SN65DSI_CHA_HIGH_SYNC_DELAY);
> +
> +	/* cha, lower 8-bits of hsync_len */
> +	regmap_write(sn->regmap, SN65DSI_CHA_HSYNC_WIDTH_LO, hsync_len & 0xff);
> +
> +	/* cha, upper 2-bits of hsync_len */
> +	regmap_write(sn->regmap, SN65DSI_CHA_HSYNC_WIDTH_HI, (hsync_len >> 8) & 0xff);
> +
> +	/* cha, lower 8-bits of vsync_len */
> +	regmap_write(sn->regmap, SN65DSI_CHA_VSYNC_WIDTH_LO, vsync_len & 0xff);
> +
> +	/* cha, upper 2-bits of vsync_len */
> +	regmap_write(sn->regmap, SN65DSI_CHA_VSYNC_WIDTH_HI, (vsync_len >> 8) & 0xff);
> +
> +	/* cha, hback_porch */
> +	regmap_write(sn->regmap, SN65DSI_CHA_HBACK_PORCH, hback_porch & 0xff);
> +
> +	/* cha, vback_porch */
> +	regmap_write(sn->regmap, SN65DSI_CHA_VBACK_PORCH, vback_porch & 0xff);
> +
> +	/* cha, hfront_porch */
> +	regmap_write(sn->regmap, SN65DSI_CHA_HFRONT_PORCH, hfront_porch & 0xff);
> +
> +	/* cha, vfront_porch */
> +	regmap_write(sn->regmap, SN65DSI_CHA_VFRONT_PORCH, vfront_porch & 0xff);
> +}
> +
> +static int sn65dsi_get_clk_range(int min, int max, unsigned long clock,
> +				 unsigned long start, unsigned long diff)
> +{
> +	unsigned long next;
> +	int i;
> +
> +	for (i = min; i <= max; i++) {
> +		next = start + diff;
> +		if (start <= clock && clock < next)
> +			return i;
> +
> +		start += diff;
> +	}
> +
> +	return -EINVAL;
> +}
> +
> +static void sn65dsi_enable(struct drm_bridge *bridge)
> +{
> +	struct sn65dsi *sn = bridge_to_sn65dsi(bridge);
> +	struct drm_display_mode *mode = bridge_to_mode(bridge);
> +	int bpp = mipi_dsi_pixel_format_to_bpp(sn->dsi->format);
> +	unsigned int lanes = sn->dsi->lanes;
> +	unsigned int pixel_clk = mode->clock * 1000;
> +	unsigned int dsi_clk = pixel_clk * bpp / (lanes * 2);
> +	unsigned int val;
> +
> +	/* reset SOFT_RESET bit */
> +	regmap_write(sn->regmap, SN65DSI_SOFT_RESET, 0x0);
> +
> +	msleep(10);
> +
> +	/* reset PLL_EN bit */
> +	regmap_write(sn->regmap, SN65DSI_CLK_PLL, 0x0);
> +
> +	msleep(10);
> +
> +	/* setup lvds clock */
> +	val = sn65dsi_get_clk_range(0, 5, pixel_clk, 25000000, 25000000);
> +	if (val < 0) {
> +		DRM_DEV_ERROR(sn->dev, "invalid LVDS clock range %d\n", val);
> +		return;
> +	}
> +
> +	regmap_update_bits(sn->regmap, SN65DSI_LVDS_CLK,
> +			   SN65DSI_LVDS_CLK_MASK,
> +			   val << SN65DSI_LVDS_CLK_SHIFT);
> +
> +	regmap_update_bits(sn->regmap, SN65DSI_LVDS_CLK,
> +			   SN65DSI_LVDS_CLK_SRC_DSI,
> +			   SN65DSI_LVDS_CLK_SRC_DSI);
> +
> +	/* setup bridge clock divider */
> +	val = (dsi_clk / pixel_clk) - 1;
> +	regmap_update_bits(sn->regmap, SN65DSI_CLK_DIV,
> +			   SN65DSI_CLK_DIV_MASK,
> +			   val << SN65DSI_CLK_DIV_SHIFT);
> +
> +	/* configure dsi */
> +	regmap_update_bits(sn->regmap, SN65DSI_DSI_CFG,
> +			   SN65DSI_DSI_LANE_MASK,
> +			   lanes << SN65DSI_DSI_LANE_SHIFT);
> +
> +	/* dsi clock range */
> +	val = sn65dsi_get_clk_range(8, 100, dsi_clk, 40000000, 5000000);
> +	if (val < 0) {
> +		DRM_DEV_ERROR(sn->dev, "invalid DSI clock range %d\n", val);
> +		return;
> +	}
> +
> +	regmap_write(sn->regmap, SN65DSI_DSI_CLK_RANGE, val);
> +
> +	/* setup lvds channels */
> +	regmap_read(sn->regmap, SN65DSI_LVDS_MODE, &val);
> +	if (bpp == 24)
> +		val |= SN65DSI_LVDS_CHA_24BPP;
> +	regmap_write(sn->regmap, SN65DSI_LVDS_MODE, val);
> +
> +	/* TODO Channel B required to set up for dual-link LVDS */
> +	sn65dsi_setup_channels(sn, mode);
> +
> +	/* set SOFT_RESET bit */
> +	regmap_write(sn->regmap, SN65DSI_SOFT_RESET, SN65DSI_RESET_EN);
> +
> +	msleep(10);
> +
> +	/* set PLL_EN bit */
> +	regmap_write(sn->regmap, SN65DSI_CLK_PLL, SN65DSI_PLL_EN);
> +
> +	msleep(10);
> +}
> +
> +static void sn65dsi_disable(struct drm_bridge *bridge)
> +{
> +	struct sn65dsi *sn = bridge_to_sn65dsi(bridge);
> +
> +	/* set PLL_EN bit */
> +	regmap_write(sn->regmap, SN65DSI_CLK_PLL, 0x0);
> +
> +	msleep(10);
> +
> +	/* set SOFT_RESET bit */
> +	regmap_write(sn->regmap, SN65DSI_SOFT_RESET, 0x0);
> +
> +	msleep(10);
> +}
> +
> +static void sn65dsi_post_disable(struct drm_bridge *bridge)
> +{
> +	struct sn65dsi *sn = bridge_to_sn65dsi(bridge);
> +
> +	gpiod_set_value_cansleep(sn->enable, 1);
> +
> +	msleep(10);
> +
> +	gpiod_set_value_cansleep(sn->enable, 0);
> +
> +	msleep(10);
> +}
> +
> +static void sn65dsi_pre_enable(struct drm_bridge *bridge)
> +{
> +	struct sn65dsi *sn = bridge_to_sn65dsi(bridge);
> +
> +	gpiod_set_value_cansleep(sn->enable, 0);
> +
> +	msleep(10);
> +
> +	gpiod_set_value_cansleep(sn->enable, 1);
> +
> +	msleep(10);
> +}
> +
> +static int sn65dsi_attach(struct drm_bridge *bridge, enum drm_bridge_attach_flags flags)
> +{
> +	struct sn65dsi *sn = bridge_to_sn65dsi(bridge);
> +	struct mipi_dsi_host *host;
> +	struct mipi_dsi_device *dsi;
> +	const struct mipi_dsi_device_info info = { .type = "sn65dsi",
> +						   .channel = 0,
> +						   .node = NULL,
> +						 };
> +	int ret;
> +
> +	host = of_find_mipi_dsi_host_by_node(sn->host_node);
> +	if (!host) {
> +		DRM_DEV_ERROR(sn->dev, "failed to find dsi host\n");
> +		return -EPROBE_DEFER;
> +	}
> +
> +	dsi = mipi_dsi_device_register_full(host, &info);
> +	if (IS_ERR(dsi)) {
> +		DRM_DEV_ERROR(sn->dev, "failed to create dsi device\n");
> +		return PTR_ERR(sn->dsi);
> +	}
> +
> +	sn->dsi = dsi;
> +	dsi->lanes = sn->dsi_lanes;
> +	dsi->format = MIPI_DSI_FMT_RGB888;
> +	dsi->mode_flags = MIPI_DSI_MODE_VIDEO;
> +
> +	ret = mipi_dsi_attach(dsi);
> +	if (ret) {
> +		DRM_DEV_ERROR(sn->dev, "failed to attach dsi host\n");
> +		goto err_dsi_attach;
> +	}
> +
> +	return drm_bridge_attach(bridge->encoder, sn->panel_bridge,
> +				 &sn->bridge, flags);
> +
> +err_dsi_attach:
> +	mipi_dsi_device_unregister(dsi);
> +	return ret;
> +}
> +
> +static const struct drm_bridge_funcs sn65dsi_bridge_funcs = {
> +	.attach		= sn65dsi_attach,
> +	.pre_enable	= sn65dsi_pre_enable,
> +	.enable		= sn65dsi_enable,
> +	.disable	= sn65dsi_disable,
> +	.post_disable	= sn65dsi_post_disable,
> +};
> +
> +static int sn65dsi_parse_dt(struct sn65dsi *sn)
> +{
> +	struct device *dev = sn->dev;
> +	struct device_node *endpoint, *parent;
> +	struct property *prop;
> +	struct drm_panel *panel;
> +	int len = 0;
> +	int ret;
> +
> +	sn->enable = devm_gpiod_get(dev, "enable", GPIOD_OUT_LOW);
> +	if (IS_ERR(sn->enable)) {
> +		DRM_DEV_ERROR(dev, "failed to get enable gpio\n");
> +		return PTR_ERR(sn->enable);
> +	}
> +
> +	ret = drm_of_find_panel_or_bridge(dev->of_node, 1, 0, &panel, NULL);
> +	if (ret < 0)
> +		return ret;
> +	if (!panel)
> +		return -ENODEV;
> +
> +	sn->panel_bridge = devm_drm_panel_bridge_add(dev, panel);
> +	if (IS_ERR(sn->panel_bridge))
> +		return PTR_ERR(sn->panel_bridge);
> +
> +	/*
> +	 * To get the data-lanes of dsi, we need to access the port1 of dsi_out
> +	 * from the port0 of bridge.
> +	 */
> +	endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 0, -1);
> +	if (endpoint) {
> +		/* dsi_out node */
> +		parent = of_graph_get_remote_port_parent(endpoint);
> +		of_node_put(endpoint);
> +		if (parent) {
> +			/* dsi port 1 */
> +			endpoint = of_graph_get_endpoint_by_regs(parent, 1, -1);
> +			of_node_put(parent);
> +			if (endpoint) {
> +				prop = of_find_property(endpoint, "data-lanes", &len);
> +				of_node_put(endpoint);
> +				if (!prop) {
> +					DRM_DEV_ERROR(dev, "failed to find data lane\n");
> +					return -EPROBE_DEFER;
> +				}
> +			}
> +		}
> +	}
> +
> +	sn->dsi_lanes = len / sizeof(u32);
> +	if (sn->dsi_lanes < 1 || sn->dsi_lanes > 4)
> +		return -EINVAL;
> +
> +	sn->host_node = of_graph_get_remote_node(dev->of_node, 0, 0);
> +	if (!sn->host_node)
> +		return -ENODEV;
> +
> +	of_node_put(sn->host_node);
> +
> +	return 0;
> +}
> +
> +static int sn65dsi_probe(struct i2c_client *client)
> +{
> +	struct sn65dsi *sn;
> +	int ret;
> +
> +	sn = devm_kzalloc(&client->dev, sizeof(*sn), GFP_KERNEL);
> +	if (!sn)
> +		return -ENOMEM;
> +
> +	i2c_set_clientdata(client, sn);
> +	sn->dev = &client->dev;
> +
> +	sn->regmap = devm_regmap_init_i2c(client, &sn65dsi_regmap_config);
> +	if (IS_ERR(sn->regmap)) {
> +		DRM_DEV_ERROR(&client->dev,
> +			      "regmap allocation failed (ret = %d)\n", ret);
> +		return PTR_ERR(sn->regmap);
> +	}
> +
> +	ret = sn65dsi_parse_dt(sn);
> +	if (ret)
> +		return ret;
> +
> +	sn->bridge.funcs = &sn65dsi_bridge_funcs;
> +	sn->bridge.of_node = client->dev.of_node;
> +
> +	drm_bridge_add(&sn->bridge);
> +
> +	return 0;
> +}
> +
> +static int sn65dsi_remove(struct i2c_client *client)
> +{
> +	struct sn65dsi *sn = i2c_get_clientdata(client);
> +
> +	drm_bridge_remove(&sn->bridge);
> +
> +	return 0;
> +}
> +
> +static struct i2c_device_id sn65dsi_i2c_id[] = {
> +	{ "sn65dsi84", 0},
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(i2c, sn65dsi_i2c_id);
> +
> +static const struct of_device_id sn65dsi_match_table[] = {
> +	{.compatible = "ti,sn65dsi84"},
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, sn65dsi_match_table);
> +
> +static struct i2c_driver sn65dsi_driver = {
> +	.driver = {
> +		.name = "ti-sn65dsi84",
> +		.of_match_table = sn65dsi_match_table,
> +	},
> +	.probe_new = sn65dsi_probe,
> +	.remove = sn65dsi_remove,
> +	.id_table = sn65dsi_i2c_id,
> +};
> +module_i2c_driver(sn65dsi_driver);
> +
> +MODULE_AUTHOR("Jagan Teki <jagan@amarulasolutions.com>");
> +MODULE_DESCRIPTION("SN65DSI84 DSI to LVDS bridge");
> +MODULE_LICENSE("GPL v2");
Marek Vasut Feb. 4, 2021, 11:20 p.m. UTC | #4 
On 2/4/21 11:29 PM, Laurent Pinchart wrote:
> Hi Jagan,
> 
> Thank you for the patch.
> 
> On Wed, Feb 03, 2021 at 12:42:56PM +0530, Jagan Teki wrote:
>> SN65DSI84 is a Single Channel DSI to Dual-link LVDS bridge from
>> Texas Instruments.
>>
>> SN65DSI83, SN65DSI85 are variants of the same family of bridge
>> controllers.
>>
>> Right now the bridge driver is supporting a single link, dual-link
>> support requires to initiate I2C Channel B registers.
> 
> MArek Vasut (on CC) has very recently posted a driver for the SN65DSI86.
> Should the two drivers be merged together ?

Since Jagan's V1 was out first, I will let Jagan pick whatever might be 
useful from the driver I posted, probably the O(1) clock rate 
calculation and some of the regmap stuff, and once there is some merged 
result, I am happy to test it on my hardware. The DSI83 is I think the 
same as DSI84, except with half of the channels.

[...]
Jagan Teki Feb. 5, 2021, 8:30 a.m. UTC | #5 
On Fri, Feb 5, 2021 at 4:50 AM Marek Vasut <marex@denx.de> wrote:
>
> On 2/4/21 11:29 PM, Laurent Pinchart wrote:
> > Hi Jagan,
> >
> > Thank you for the patch.
> >
> > On Wed, Feb 03, 2021 at 12:42:56PM +0530, Jagan Teki wrote:
> >> SN65DSI84 is a Single Channel DSI to Dual-link LVDS bridge from
> >> Texas Instruments.
> >>
> >> SN65DSI83, SN65DSI85 are variants of the same family of bridge
> >> controllers.
> >>
> >> Right now the bridge driver is supporting a single link, dual-link
> >> support requires to initiate I2C Channel B registers.
> >
> > MArek Vasut (on CC) has very recently posted a driver for the SN65DSI86.
> > Should the two drivers be merged together ?
>
> Since Jagan's V1 was out first, I will let Jagan pick whatever might be
> useful from the driver I posted, probably the O(1) clock rate
> calculation and some of the regmap stuff, and once there is some merged
> result, I am happy to test it on my hardware. The DSI83 is I think the
> same as DSI84, except with half of the channels.

Thanks. please wait for the v3 series, we can discuss further on top.

Jagan.
diff mbox series

Patch

diff --git a/Documentation/devicetree/bindings/display/bridge/ti,sn65dsi84.yaml b/Documentation/devicetree/bindings/display/bridge/ti,sn65dsi84.yaml
new file mode 100644
index 000000000000..891382a76c1a
--- /dev/null
+++ b/Documentation/devicetree/bindings/display/bridge/ti,sn65dsi84.yaml
@@ -0,0 +1,127 @@ 
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/display/bridge/ti,sn65dsi84.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: TI SN65DSI84 MIPI DSI to LVDS bridge bindings
+
+maintainers:
+  - Jagan Teki <jagan@amarulasolutions.com>
+
+description: |
+  The SN65DSI84 DSI to FlatLink bridge features a single channel MIPI D-PHY receiver
+  front-end configuration with 4 lanes per channel operating at 1 Gbps per lanes.
+  The bridge decodes MIPI DSI 18bpp RGB666 and 240bpp RG888 packets and converts
+  the formatted video data stream to a FlatLink compatible LVDS output operating
+  at pixel clocks operating from 25 MHx to 154 MHz, offering a Dual-Link LVDS,
+  Single-Link LVDS interface with four data lanes per link.
+
+  https://www.ti.com/product/SN65DSI84
+
+properties:
+  compatible:
+    const: ti,sn65dsi84
+
+  reg:
+    maxItems: 1
+    description: i2c address of the bridge, 0x2c
+
+  enable-gpios:
+    maxItems: 1
+    description: GPIO specifier for bridge enable pin (active high).
+
+  ports:
+    type: object
+    description:
+      A node containing input and output port nodes with endpoint definitions
+      as documented in
+      Documentation/devicetree/bindings/media/video-interfaces.txt
+    properties:
+      "#address-cells":
+        const: 1
+
+      "#size-cells":
+        const: 0
+
+      port@0:
+        type: object
+        description: |
+          DSI Input. The remote endpoint phandle should be a
+          reference to a valid mipi_dsi_host device node.
+
+      port@1:
+        type: object
+        description: |
+          Video port for LVDS output (panel or connector).
+
+    required:
+      - port@0
+      - port@1
+
+required:
+  - compatible
+  - reg
+  - enable-gpios
+  - ports
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+
+    dsi {
+       #address-cells = <1>;
+       #size-cells = <0>;
+
+       ports {
+           #address-cells = <1>;
+           #size-cells = <0>;
+
+           port@0 {
+               reg = <0>;
+               dsi_in: endpoint {
+                   remote-endpoint = <&ltdc_ep0_out>;
+               };
+           };
+
+           port@1 {
+               reg = <1>;
+               dsi_out: endpoint {
+                   remote-endpoint = <&bridge_in>;
+                   data-lanes = <0 1>;
+               };
+           };
+       };
+    };
+
+    i2c6 {
+       #address-cells = <1>;
+       #size-cells = <0>;
+
+       bridge@2c {
+           compatible = "ti,sn65dsi84";
+           reg = <0x2c>;
+           enable-gpios = <&gpiof 15 GPIO_ACTIVE_HIGH>;
+
+           ports {
+               #address-cells = <1>;
+               #size-cells = <0>;
+
+               port@0 {
+                   reg = <0>;
+                   bridge_in: endpoint {
+                        remote-endpoint = <&dsi_out>;
+                   };
+               };
+
+               port@1 {
+                   reg = <1>;
+                   bridge_out: endpoint {
+                        remote-endpoint = <&panel_in_lvds>;
+                   };
+               };
+           };
+       };
+    };