Hi GVRao,
Thank you for the patch.
On Thu, Jun 16, 2022 at 07:47:36PM +0530, Venkateshwar Rao Gannavarapu wrote:
> The Xilinx MIPI DSI Tx Subsystem soft IP is used to display video
> data from AXI-4 stream interface.
>
> It supports upto 4 lanes, optional register interface for the DPHY
> and multiple RGB color formats.
> This is a MIPI-DSI host driver and provides DSI bus for panels.
> This driver also helps to communicate with its panel using panel
> framework.
>
> Signed-off-by: Venkateshwar Rao Gannavarapu <venkateshwar.rao.gannavarapu@xxxxxxxxxx>
> ---
> drivers/gpu/drm/xlnx/Kconfig | 12 ++
> drivers/gpu/drm/xlnx/Makefile | 1 +
> drivers/gpu/drm/xlnx/xlnx_dsi.c | 429 ++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 442 insertions(+)
> create mode 100644 drivers/gpu/drm/xlnx/xlnx_dsi.c
>
> diff --git a/drivers/gpu/drm/xlnx/Kconfig b/drivers/gpu/drm/xlnx/Kconfig
> index f9cf93c..a75bd76 100644
> --- a/drivers/gpu/drm/xlnx/Kconfig
> +++ b/drivers/gpu/drm/xlnx/Kconfig
> @@ -1,3 +1,15 @@
> +config DRM_XLNX_DSI
> + tristate "Xilinx DRM DSI Subsystem Driver"
> + depends on ARCH_ZYNQMP || COMPILE_TEST
> + depends on DRM && OF
> + select DRM_KMS_HELPER
> + select DRM_MIPI_DSI
> + select DRM_PANEL_BRIDGE
You can drop DRM_PANEL_BRIDGE, the driver doesn't need it.
> + help
> + DRM bridge driver for Xilinx programmable DSI subsystem controller.
> + choose this option if you hava a Xilinx MIPI-DSI Tx subsytem in
s/choose/Choose/
> + video pipeline.
> +
> config DRM_ZYNQMP_DPSUB
> tristate "ZynqMP DisplayPort Controller Driver"
> depends on ARCH_ZYNQMP || COMPILE_TEST
> diff --git a/drivers/gpu/drm/xlnx/Makefile b/drivers/gpu/drm/xlnx/Makefile
> index 51c24b7..f90849b 100644
> --- a/drivers/gpu/drm/xlnx/Makefile
> +++ b/drivers/gpu/drm/xlnx/Makefile
> @@ -1,2 +1,3 @@
> +obj-$(CONFIG_DRM_XLNX_DSI) += xlnx_dsi.o
> zynqmp-dpsub-y := zynqmp_disp.o zynqmp_dpsub.o zynqmp_dp.o
> obj-$(CONFIG_DRM_ZYNQMP_DPSUB) += zynqmp-dpsub.o
> diff --git a/drivers/gpu/drm/xlnx/xlnx_dsi.c b/drivers/gpu/drm/xlnx/xlnx_dsi.c
> new file mode 100644
> index 0000000..39d8947
> --- /dev/null
> +++ b/drivers/gpu/drm/xlnx/xlnx_dsi.c
> @@ -0,0 +1,429 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Xilinx FPGA MIPI DSI Tx Controller driver.
> + *
> + * Copyright (C) 2022 Xilinx, Inc.
> + *
> + * Author: Venkateshwar Rao Gannavarapu <venkateshwar.rao.gannavarapu@xxxxxxxxxx>
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/module.h>
> +#include <linux/of_device.h>
I'd add at least platform_device.h to avoid depending on indirect
inclusion of headers.
> +
> +#include <drm/drm_atomic_helper.h>
> +#include <drm/drm_bridge.h>
> +#include <drm/drm_mipi_dsi.h>
> +#include <drm/drm_modes.h>
> +#include <drm/drm_of.h>
> +#include <drm/drm_panel.h>
Not needed.
> +#include <drm/drm_print.h>
> +
> +/* DSI Tx IP registers */
> +#define XDSI_CCR 0x00
> +#define XDSI_CCR_COREENB BIT(0)
> +#define XDSI_CCR_SOFTRST BIT(1)
> +#define XDSI_CCR_CRREADY BIT(2)
> +#define XDSI_CCR_CMDMODE BIT(3)
> +#define XDSI_CCR_DFIFORST BIT(4)
> +#define XDSI_CCR_CMDFIFORST BIT(5)
> +#define XDSI_PCR 0x04
> +#define XDSI_PCR_LANES_MASK 3
> +#define XDSI_PCR_VIDEOMODE(x) (((x) & 0x3) << 3)
> +#define XDSI_PCR_VIDEOMODE_MASK GENMASK(4, 3)
> +#define XDSI_PCR_VIDEOMODE_SHIFT 3
> +#define XDSI_PCR_BLLPTYPE(x) ((x) << 5)
> +#define XDSI_PCR_BLLPMODE(x) ((x) << 6)
> +#define XDSI_PCR_PIXELFORMAT_MASK GENMASK(12, 11)
> +#define XDSI_PCR_PIXELFORMAT_SHIFT 11
> +#define XDSI_PCR_EOTPENABLE(x) ((x) << 13)
> +#define XDSI_GIER 0x20
> +#define XDSI_ISR 0x24
> +#define XDSI_IER 0x28
> +#define XDSI_STR 0x2C
> +#define XDSI_STR_RDY_SHPKT BIT(6)
> +#define XDSI_STR_RDY_LNGPKT BIT(7)
> +#define XDSI_STR_DFIFO_FULL BIT(8)
> +#define XDSI_STR_DFIFO_EMPTY BIT(9)
> +#define XDSI_STR_WAITFR_DATA BIT(10)
> +#define XDSI_STR_CMD_EXE_PGS BIT(11)
> +#define XDSI_STR_CCMD_PROC BIT(12)
> +#define XDSI_CMD 0x30
> +#define XDSI_CMD_QUEUE_PACKET(x) ((x) & GENMASK(23, 0))
> +#define XDSI_DFR 0x34
> +#define XDSI_TIME1 0x50
> +#define XDSI_TIME1_BLLP_BURST(x) ((x) & GENMASK(15, 0))
> +#define XDSI_TIME1_HSA(x) (((x) & GENMASK(15, 0)) << 16)
> +#define XDSI_TIME2 0x54
> +#define XDSI_TIME2_VACT(x) ((x) & GENMASK(15, 0))
> +#define XDSI_TIME2_HACT(x) (((x) & GENMASK(15, 0)) << 16)
> +#define XDSI_HACT_MULTIPLIER GENMASK(1, 0)
> +#define XDSI_TIME3 0x58
> +#define XDSI_TIME3_HFP(x) ((x) & GENMASK(15, 0))
> +#define XDSI_TIME3_HBP(x) (((x) & GENMASK(15, 0)) << 16)
> +#define XDSI_TIME4 0x5c
> +#define XDSI_TIME4_VFP(x) ((x) & GENMASK(7, 0))
> +#define XDSI_TIME4_VBP(x) (((x) & GENMASK(7, 0)) << 8)
> +#define XDSI_TIME4_VSA(x) (((x) & GENMASK(7, 0)) << 16)
> +#define XDSI_NUM_DATA_T 4
> +
> +/**
> + * struct xlnx_dsi - Xilinx DSI-TX core
> + * @bridge: DRM bridge structure
> + * @dsi_host: DSI host device
> + * @next_bridge: bridge structure
> + * @dev: device structure
> + * @clks: clock source structure
> + * @iomem: Base address of DSI subsystem
> + * @mode_flags: DSI operation mode related flags
> + * @lanes: number of active data lanes supported by DSI controller
> + * @mul_factor: multiplication factor for HACT timing
> + * @format: pixel format for video mode of DSI controller
> + * @device_found: Flag to indicate device presence
> + */
> +struct xlnx_dsi {
> + struct drm_bridge bridge;
> + struct mipi_dsi_host dsi_host;
> + struct drm_bridge *next_bridge;
> + struct device *dev;
> + struct clk_bulk_data *clks;
> + void __iomem *iomem;
> + unsigned long mode_flags;
> + u32 lanes;
> + u32 mul_factor;
> + enum mipi_dsi_pixel_format format;
> + bool device_found;
> +};
> +
> +static const struct clk_bulk_data xdsi_clks[] = {
> + { .id = "s_axis_aclk" },
> + { .id = "dphy_clk_200M" },
> +};
> +
> +static inline struct xlnx_dsi *host_to_dsi(struct mipi_dsi_host *host)
> +{
> + return container_of(host, struct xlnx_dsi, dsi_host);
> +}
> +
> +static inline struct xlnx_dsi *bridge_to_dsi(struct drm_bridge *bridge)
> +{
> + return container_of(bridge, struct xlnx_dsi, bridge);
> +}
> +
> +static inline void xlnx_dsi_write(struct xlnx_dsi *dsi, int offset, u32 val)
> +{
> + writel(val, dsi->iomem + offset);
> +}
> +
> +static inline u32 xlnx_dsi_read(struct xlnx_dsi *dsi, int offset)
> +{
> + return readl(dsi->iomem + offset);
> +}
> +
> +static int xlnx_dsi_host_attach(struct mipi_dsi_host *host,
> + struct mipi_dsi_device *device)
> +{
> + struct xlnx_dsi *dsi = host_to_dsi(host);
> + struct device *dev = host->dev;
> +
> + dsi->mode_flags = device->mode_flags;
> +
> + if (dsi->lanes != device->lanes) {
> + dev_err(dsi->dev, "Mismatch of lanes. panel = %d, DSI = %d\n",
It's not necessarily a panel. You can write
dev_err(dsi->dev, "Mismatch of lanes, host: %u != device: %u\n",
dsi->lanes, device->lanes);
> + device->lanes, dsi->lanes);
> + return -EINVAL;
> + }
> +
> + if (dsi->format != device->format) {
> + dev_err(dsi->dev, "Mismatch of format. panel = %d, DSI = %d\n",
> + device->format, dsi->format);
Same here.
> + return -EINVAL;
> + }
> +
> + if (!dsi->device_found) {
> + dsi->next_bridge = devm_drm_of_get_bridge(dev,
As dev is the same as dsi->dev, I'd use dev->dsi here and drop the local
variable.
> + dev->of_node, 0, 0);
> + if (IS_ERR(dsi->next_bridge))
> + return PTR_ERR(dsi->next_bridge);
> + drm_bridge_add(&dsi->bridge);
> + dsi->device_found = true;
I don't think the device_found flag mechanism is right. You remove the
bridge in xlnx_dsi_host_detach(), so it should be added back here,
shouldn't it ?
The next question would then be what to do with the next bridge acquired
with devm_drm_of_get_bridge(). It looks like we have a lifetime
management issue here, and I don't think it's fair to ask you to fix the
bridge/panel core to get this driver merged, so I'm fine keeping this
for now even if it's incorrect. I'd like feedback from others though.
> + }
> +
> + return 0;
> +}
> +
> +static int xlnx_dsi_host_detach(struct mipi_dsi_host *host,
> + struct mipi_dsi_device *device)
> +{
> + struct xlnx_dsi *dsi = host_to_dsi(host);
> +
> + drm_bridge_remove(&dsi->bridge);
> + return 0;
> +}
> +
> +static const struct mipi_dsi_host_ops xlnx_dsi_ops = {
> + .attach = xlnx_dsi_host_attach,
> + .detach = xlnx_dsi_host_detach,
> +};
> +
> +static void
> +xlnx_dsi_bridge_disable(struct drm_bridge *bridge,
> + struct drm_bridge_state *old_bridge_state)
> +{
> + struct xlnx_dsi *dsi = bridge_to_dsi(bridge);
> + u32 reg = xlnx_dsi_read(dsi, XDSI_CCR);
> +
> + reg &= ~XDSI_CCR_COREENB;
> + xlnx_dsi_write(dsi, XDSI_CCR, reg);
> +}
> +
> +static void
> +xlnx_dsi_bridge_enable(struct drm_bridge *bridge,
> + struct drm_bridge_state *old_bridge_state)
> +{
> + struct xlnx_dsi *dsi = bridge_to_dsi(bridge);
> + struct drm_atomic_state *state = old_bridge_state->base.state;
> + struct drm_connector *connector;
> + struct drm_crtc *crtc;
> + const struct drm_crtc_state *crtc_state;
> + const struct drm_display_mode *mode;
> + u32 reg, video_mode;
> +
> + connector = drm_atomic_get_new_connector_for_encoder(state,
> + bridge->encoder);
> + crtc = drm_atomic_get_new_connector_state(state, connector)->crtc;
> + crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
> + mode = &crtc_state->adjusted_mode;
> +
> + reg = xlnx_dsi_read(dsi, XDSI_PCR);
> + video_mode = (reg & XDSI_PCR_VIDEOMODE_MASK) >> XDSI_PCR_VIDEOMODE_SHIFT;
> +
> + if (!video_mode && (dsi->mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE)) {
> + reg = XDSI_TIME1_HSA(mode->hsync_end -
> + mode->hsync_start);
This holds on a single line.
> + xlnx_dsi_write(dsi, XDSI_TIME1, reg);
> + }
> +
> + reg = XDSI_TIME4_VFP(mode->vsync_start - mode->vdisplay) |
> + XDSI_TIME4_VBP(mode->vtotal - mode->vsync_end) |
> + XDSI_TIME4_VSA(mode->vsync_end - mode->vsync_start);
> + xlnx_dsi_write(dsi, XDSI_TIME4, reg);
> +
> + reg = XDSI_TIME3_HFP(mode->hsync_start - mode->hdisplay) |
> + XDSI_TIME3_HBP(mode->htotal - mode->hsync_end);
> + xlnx_dsi_write(dsi, XDSI_TIME3, reg);
> +
> + reg = XDSI_TIME2_HACT(mode->hdisplay * dsi->mul_factor / 100) |
> + XDSI_TIME2_VACT(mode->vdisplay);
> + xlnx_dsi_write(dsi->iomem, XDSI_TIME2, reg);
> +
> + xlnx_dsi_write(dsi, XDSI_PCR, XDSI_PCR_VIDEOMODE(BIT(0)));
> +
> + /* Enable Core */
> + reg = xlnx_dsi_read(dsi, XDSI_CCR);
> + reg |= XDSI_CCR_COREENB;
> + xlnx_dsi_write(dsi, XDSI_CCR, reg);
> +}
> +
> +#define MAX_INPUT_SEL_FORMATS 3
> +static u32
> +*xlnx_dsi_bridge_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
> + struct drm_bridge_state *bridge_state,
> + struct drm_crtc_state *crtc_state,
> + struct drm_connector_state *conn_state,
> + u32 output_fmt,
> + unsigned int *num_input_fmts)
> +{
> + u32 *input_fmts;
> + unsigned int i = 0;
> +
> + *num_input_fmts = 0;
> + input_fmts = kcalloc(MAX_INPUT_SEL_FORMATS, sizeof(*input_fmts), GFP_KERNEL);
> + if (!input_fmts)
> + return NULL;
> +
> + switch (output_fmt) {
> + case MEDIA_BUS_FMT_FIXED:
> + input_fmts[i++] = MEDIA_BUS_FMT_RGB888_1X24;
> + break;
> + case MEDIA_BUS_FMT_RGB666_1X18:
> + input_fmts[i++] = MEDIA_BUS_FMT_RGB666_1X18;
> + break;
> + case MEDIA_BUS_FMT_RGB565_1X16:
> + input_fmts[i++] = MEDIA_BUS_FMT_RGB565_1X16;
> + break;
> + default: /* define */
> + }
As the cases are mutually exclusive, i will always be equal to 1. You
can drop the MAX_INPUT_SEL_FORMATS macro, the i variable, allocate a
single entry for input_fmts, and set inputs_fmts[0].
> +
> + *num_input_fmts = i;
> + if (*num_input_fmts == 0) {
> + kfree(input_fmts);
> + input_fmts = NULL;
> + }
> +
> + return input_fmts;
> +}
> +
> +static int xlnx_dsi_bridge_attach(struct drm_bridge *bridge,
> + enum drm_bridge_attach_flags flags)
> +{
> + struct xlnx_dsi *dsi = bridge_to_dsi(bridge);
> +
> + if (!dsi->next_bridge)
Can this ever happen ?
> + return 0;
> +
> + /* Attach the next bridge */
> + return drm_bridge_attach(bridge->encoder, dsi->next_bridge, bridge,
> + flags);
> +}
> +
> +static void xlnx_dsi_bridge_detach(struct drm_bridge *bridge)
> +{
> + struct xlnx_dsi *dsi = bridge_to_dsi(bridge);
> +
> + drm_of_panel_bridge_remove(dsi->dev->of_node, 1, 0);
This doesn't look right. Is it a leftover ? You should instead call
drm_bridge_detach() on the next bridge.
> +}
> +
> +static enum drm_mode_status
> +xlnx_dsi_bridge_mode_valid(struct drm_bridge *bridge,
> + const struct drm_display_info *info,
> + const struct drm_display_mode *mode)
> +{
> + if ((mode->hdisplay & XDSI_HACT_MULTIPLIER) != 0)
> + return MODE_BAD_WIDTH;
> +
> + return MODE_OK;
> +}
> +
> +static const struct drm_bridge_funcs xlnx_dsi_bridge_funcs = {
> + .atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
> + .atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
> + .atomic_reset = drm_atomic_helper_bridge_reset,
> + .atomic_disable = xlnx_dsi_bridge_disable,
> + .atomic_enable = xlnx_dsi_bridge_enable,
> + .atomic_get_input_bus_fmts = xlnx_dsi_bridge_atomic_get_input_bus_fmts,
> + .attach = xlnx_dsi_bridge_attach,
> + .detach = xlnx_dsi_bridge_detach,
> + .mode_valid = xlnx_dsi_bridge_mode_valid,
> +};
> +
> +static int xlnx_dsi_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct resource *res;
> + struct xlnx_dsi *dsi;
> + int ret;
> + const int xdsi_mul_fact[XDSI_NUM_DATA_T] = {300, 225, 225, 200};
static const, and you can move it as the first variable of the function.
> + u32 reg;
> +
> + dsi = devm_kzalloc(dev, sizeof(*dsi), GFP_KERNEL);
> + if (!dsi)
> + return -ENOMEM;
> +
> + dsi->dev = dev;
> + dsi->clks = devm_kmemdup(dev, xdsi_clks, sizeof(xdsi_clks),
> + GFP_KERNEL);
> + if (!dsi->clks)
> + return -ENOMEM;
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + dsi->iomem = devm_ioremap_resource(dev, res);
> + if (IS_ERR(dsi->iomem))
> + return PTR_ERR(dsi->iomem);
> +
> + ret = devm_clk_bulk_get(dev, ARRAY_SIZE(xdsi_clks), dsi->clks);
> + if (ret)
> + return ret;
> +
> + ret = clk_bulk_prepare_enable(ARRAY_SIZE(xdsi_clks), dsi->clks);
> + if (ret)
> + return ret;
Shouldn't this be done in the .atomic_enable() handler instead, possible
through runtime PM ?
> +
> + platform_set_drvdata(pdev, dsi);
> + dsi->dsi_host.ops = &xlnx_dsi_ops;
> + dsi->dsi_host.dev = dev;
> +
> + ret = mipi_dsi_host_register(&dsi->dsi_host);
> + if (ret) {
> + dev_err(dev, "Failed to register MIPI host: %d\n", ret);
> + goto err_clk_put;
> + }
> +
> + dsi->bridge.driver_private = dsi;
> + dsi->bridge.funcs = &xlnx_dsi_bridge_funcs;
> + dsi->bridge.of_node = pdev->dev.of_node;
> +
> + reg = xlnx_dsi_read(dsi, XDSI_PCR);
> + dsi->lanes = reg & XDSI_PCR_LANES_MASK;
> + dsi->format = (reg & XDSI_PCR_PIXELFORMAT_MASK) >>
> + XDSI_PCR_PIXELFORMAT_SHIFT;
OK, you'll need to enable clocks for this too, so runtime PM could be a
good option.
> +
> + if (dsi->lanes > 4 || dsi->lanes < 1) {
> + dev_err(dsi->dev, "%d invalid lanes\n", dsi->lanes);
dsi->lanes is unsigned, so %u.
> + return -EINVAL;
This leaves the clocks enabled.
> + }
> +
> + if (dsi->format > MIPI_DSI_FMT_RGB565) {
> + dev_err(dsi->dev, "Invalid xlnx,dsi-data-type string\n");
This is read from a register, not parsed from DT, so the message isn't
valid.
> + return -EINVAL;
> + }
> +
> + /*
> + * Used as a multiplication factor for HACT based on used
> + * DSI data type.
> + *
> + * e.g. for RGB666_L datatype and 1920x1080 resolution,
> + * the Hact (WC) would be as follows -
> + * 1920 pixels * 18 bits per pixel / 8 bits per byte
> + * = 1920 pixels * 2.25 bytes per pixel = 4320 bytes.
> + *
> + * Data Type - Multiplication factor
> + * RGB888 - 3
> + * RGB666_L - 2.25
> +- * RGB666_P - 2.25
> + * RGB565 - 2
> + *
> + * Since the multiplication factor is a floating number,
> + * a 100x multiplication factor is used.
> + */
> + dsi->mul_factor = xdsi_mul_fact[dsi->format];
> +
> + dev_dbg(dsi->dev, "DSI controller num lanes = %d\n", dsi->lanes);
> + dev_dbg(dsi->dev, "DSI controller format = %d\n", dsi->format);
You could combine both messages into a single one.
Are you missing a return 0 here ?
> +
> +err_clk_put:
> + clk_bulk_disable_unprepare(ARRAY_SIZE(xdsi_clks), dsi->clks);
> +
> + return ret;
> +}
> +
> +static int xlnx_dsi_remove(struct platform_device *pdev)
> +{
> + struct xlnx_dsi *dsi = platform_get_drvdata(pdev);
> +
> + mipi_dsi_host_unregister(&dsi->dsi_host);
> + clk_bulk_disable_unprepare(ARRAY_SIZE(xdsi_clks), dsi->clks);
> +
> + return 0;
> +}
> +
> +static const struct of_device_id xlnx_dsi_of_match[] = {
> + { .compatible = "xlnx,dsi-tx-v2.0"},
> + { }
> +};
> +MODULE_DEVICE_TABLE(of, xlnx_dsi_of_match);
> +
> +static struct platform_driver dsi_driver = {
> + .probe = xlnx_dsi_probe,
> + .remove = xlnx_dsi_remove,
> + .driver = {
> + .name = "xlnx-dsi",
> + .of_match_table = xlnx_dsi_of_match,
> + },
> +};
> +
> +module_platform_driver(dsi_driver);
> +
> +MODULE_AUTHOR("Venkateshwar Rao Gannavarapu <venkateshwar.rao.gannavarapu@xxxxxxxxxx>");
> +MODULE_DESCRIPTION("Xilinx MIPI DSI host controller driver");
> +MODULE_LICENSE("GPL");
--
Regards,
Laurent Pinchart
