Hi,
On 08/31/2017 09:25 PM, Boris Brezillon wrote:
Add a driver for Cadence DPI -> DSI bridge.
This driver only support a subset of Cadence DSI bridge capabilities.
Here is a non-exhaustive list of missing features:
* burst mode
* dynamic configuration of the DPHY based on the
* support for additional input interfaces (SDI input)
Signed-off-by: Boris Brezillon <boris.brezil...@free-electrons.com>
---
Changes in v3:
- replace magic values by real timing calculation. The DPHY PLL clock
is still hardcoded since we don't have a working DPHY block yet, and
this is the piece of HW we need to dynamically configure the PLL
rate based on the display refresh rate and the resolution.
- parse DSI devices represented with the OF-graph. This is needed to
support DSI devices controlled through an external bus like I2C or
SPI.
- use the DRM panel-bridge infrastructure to simplify the DRM panel
logic
Changes in v2:
- rebase on v4.12-rc1 and adapt to driver to the drm_bridge API changes
- return the correct error when devm_clk_get(sysclk) fails
- add missing depends on OF and select DRM_PANEL in the Kconfig entry
---
drivers/gpu/drm/bridge/Kconfig | 9 +
drivers/gpu/drm/bridge/Makefile | 1 +
drivers/gpu/drm/bridge/cdns-dsi.c | 1090 +++++++++++++++++++++++++++++++++++++
3 files changed, 1100 insertions(+)
create mode 100644 drivers/gpu/drm/bridge/cdns-dsi.c
diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
index adf9ae0e0b7c..88c324b12e16 100644
--- a/drivers/gpu/drm/bridge/Kconfig
+++ b/drivers/gpu/drm/bridge/Kconfig
@@ -25,6 +25,15 @@ config DRM_ANALOGIX_ANX78XX
the HDMI output of an application processor to MyDP
or DisplayPort.
+config DRM_CDNS_DSI
+ tristate "Cadence DPI/DSI bridge"
+ select DRM_KMS_HELPER
+ select DRM_MIPI_DSI
+ select DRM_PANEL
+ depends on OF
+ help
+ Support Cadence DPI to DSI bridge.
Maybe we can briefly mention here that it's a internal bridge/IP, and not an
external chip?
+
config DRM_DUMB_VGA_DAC
tristate "Dumb VGA DAC Bridge support"
depends on OF
diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
index defcf1e7ca1c..77b65e8ecf59 100644
--- a/drivers/gpu/drm/bridge/Makefile
+++ b/drivers/gpu/drm/bridge/Makefile
@@ -1,4 +1,5 @@
obj-$(CONFIG_DRM_ANALOGIX_ANX78XX) += analogix-anx78xx.o
+obj-$(CONFIG_DRM_CDNS_DSI) += cdns-dsi.o
obj-$(CONFIG_DRM_DUMB_VGA_DAC) += dumb-vga-dac.o
obj-$(CONFIG_DRM_LVDS_ENCODER) += lvds-encoder.o
obj-$(CONFIG_DRM_MEGACHIPS_STDPXXXX_GE_B850V3_FW) +=
megachips-stdpxxxx-ge-b850v3-fw.o
diff --git a/drivers/gpu/drm/bridge/cdns-dsi.c
b/drivers/gpu/drm/bridge/cdns-dsi.c
<snip>
+
+static void cdns_dsi_bridge_disable(struct drm_bridge *bridge)
+{
+ struct cdns_dsi_input *input = bridge_to_cdns_dsi_input(bridge);
+ struct cdns_dsi *dsi = input_to_dsi(input);
+ u32 val;
+
+ val = readl(dsi->regs + MCTL_MAIN_DATA_CTL);
+ val &= ~(IF_VID_SELECT_MASK | IF_VID_MODE | VID_EN | HOST_EOT_GEN |
+ DISP_EOT_GEN);
I see some truncation related sparse warnings here and a couple of other places
when building against arm32. Those would be nice to fix.
+ writel(val, dsi->regs + MCTL_MAIN_DATA_CTL);
+
+ val = readl(dsi->regs + MCTL_MAIN_EN) & ~IF_EN(input->id);
+ writel(val, dsi->regs + MCTL_MAIN_EN);
+}
+
+#define DSI_HBP_FRAME_OVERHEAD 12
+#define DSI_HSA_FRAME_OVERHEAD 14
+#define DSI_HFP_FRAME_OVERHEAD 6
+#define DSI_HSS_VSS_VSE_FRAME_OVERHEAD 4
+#define DSI_BLANKING_FRAME_OVERHEAD 6
+#define DSI_NULL_FRAME_OVERHEAD 6
+#define DSI_EOT_PKT_SIZE 4
+
+#define REG_WAKEUP_TIME_NS 800
+#define DPHY_PLL_RATE_HZ 108000000
+
+static void cdns_dsi_bridge_enable(struct drm_bridge *bridge)
+{
+ struct cdns_dsi_input *input = bridge_to_cdns_dsi_input(bridge);
+ struct cdns_dsi *dsi = input_to_dsi(input);
+ struct cdns_dsi_output *output = &dsi->output;
+ u32 hsize0, hsa, hline, tmp, reg_wakeup, div;
+ unsigned long dphy_pll_period, tx_byte_period;
+ struct drm_display_mode *mode;
+ int bpp, nlanes;
+
+ mode = &bridge->encoder->crtc->state->adjusted_mode;
+ bpp = mipi_dsi_pixel_format_to_bpp(output->dev->format);
+ nlanes = output->dev->lanes;
+
+ if (output->dev->mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE)
+ tmp = mode->crtc_htotal - mode->crtc_hsync_end;
+ else
+ tmp = mode->crtc_htotal - mode->crtc_hsync_start;
+ tmp = (tmp * bpp) / 8;
+ tmp = tmp < DSI_HBP_FRAME_OVERHEAD ? 0 : tmp - DSI_HBP_FRAME_OVERHEAD;
+ hsize0 = HBP_LEN(tmp);
+
+ tmp = mode->crtc_hsync_start - mode->crtc_hdisplay;
+ tmp = (tmp * bpp) / 8;
+ tmp = tmp < DSI_HFP_FRAME_OVERHEAD ? 0 : tmp - DSI_HFP_FRAME_OVERHEAD;
+ hsize0 |= HFP_LEN(tmp);
+
+ if (output->dev->mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE)
+ tmp = mode->crtc_hsync_end - mode->crtc_hsync_start;
+ else
+ tmp = 0;
+ tmp = (tmp * 8) / bpp;
+ tmp = tmp < DSI_HSA_FRAME_OVERHEAD ? 0 : tmp - DSI_HSA_FRAME_OVERHEAD;
+ hsa = tmp;
+ hsize0 |= HSA_LEN(tmp);
+
+ writel(hsize0, dsi->regs + VID_HSIZE1);
+ writel((mode->crtc_hdisplay * bpp) / 8, dsi->regs + VID_HSIZE2);
+
+ writel(VBP_LEN(mode->crtc_vtotal - mode->crtc_vsync_end - 1) |
+ VFP_LEN(mode->crtc_vsync_start - mode->crtc_vdisplay) |
+ VSA_LEN(mode->crtc_vsync_end - mode->crtc_vsync_start),
+ dsi->regs + VID_VSIZE1);
+ writel(mode->crtc_vdisplay, dsi->regs + VID_VSIZE2);
+
+ hline = (mode->crtc_htotal * bpp) / 8;
+ tmp = hline - DSI_HSA_FRAME_OVERHEAD;
+ if (output->dev->mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE)
+ tmp -= hsa + DSI_HSA_FRAME_OVERHEAD;
+
+ writel(BLK_LINE_PULSE_PKT_LEN(tmp), dsi->regs + VID_BLKSIZE2);
+ if (output->dev->mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE)
+ writel(MAX_LINE_LIMIT(tmp - DSI_NULL_FRAME_OVERHEAD),
+ dsi->regs + VID_VCA_SETTING2);
+
+ tmp = hline -
+ (DSI_HSS_VSS_VSE_FRAME_OVERHEAD + DSI_BLANKING_FRAME_OVERHEAD);
+ writel(BLK_LINE_EVENT_PKT_LEN(tmp), dsi->regs + VID_BLKSIZE1);
+ if (!(output->dev->mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE))
+ writel(MAX_LINE_LIMIT(tmp - DSI_NULL_FRAME_OVERHEAD),
+ dsi->regs + VID_VCA_SETTING2);
+
+ tmp = DIV_ROUND_UP(hline, nlanes) - DIV_ROUND_UP(hsa, nlanes);
+
+ if (!(output->dev->mode_flags & MIPI_DSI_MODE_EOT_PACKET))
+ tmp -= DIV_ROUND_UP(DSI_EOT_PKT_SIZE, nlanes);
+
+ dphy_pll_period = NSEC_PER_SEC / DPHY_PLL_RATE_HZ;
+ tx_byte_period = (dphy_pll_period * 2) / 8;
+ reg_wakeup = REG_WAKEUP_TIME_NS / dphy_pll_period;
+ writel(REG_WAKEUP_TIME(reg_wakeup) | REG_LINE_DURATION(tmp),
+ dsi->regs + VID_DPHY_TIME);
+
+ /*
+ * HSTX and LPRX timeouts are both expressed in TX byte clk cycles and
+ * both should be set to at least the time it takes to transmit a
+ * frame.
+ */
+ tmp = NSEC_PER_SEC / mode->vrefresh;
+ tmp /= tx_byte_period;
+
+ for (div = 0; div <= CLK_DIV_MAX; div++) {
+ if (tmp <= HSTX_TIMEOUT_MAX)
+ break;
+
+ tmp >>= 1;
+ }
+
+ if (tmp > HSTX_TIMEOUT_MAX)
+ tmp = HSTX_TIMEOUT_MAX;
+
+ writel(CLK_DIV(div) | HSTX_TIMEOUT(tmp),
+ dsi->regs + MCTL_DPHY_TIMEOUT1);
+
+ writel(LPRX_TIMEOUT(tmp), dsi->regs + MCTL_DPHY_TIMEOUT2);
+
+ if (output->dev->mode_flags & MIPI_DSI_MODE_VIDEO) {
+ switch (output->dev->format) {
+ case MIPI_DSI_FMT_RGB888:
+ tmp = VID_PIXEL_MODE_RGB888 |
+ VID_DATATYPE(MIPI_DSI_PACKED_PIXEL_STREAM_24);
+ break;
+
+ case MIPI_DSI_FMT_RGB666:
+ tmp = VID_PIXEL_MODE_RGB666 |
+ VID_DATATYPE(MIPI_DSI_PIXEL_STREAM_3BYTE_18);
+ break;
+
+ case MIPI_DSI_FMT_RGB666_PACKED:
+ tmp = VID_PIXEL_MODE_RGB666_PACKED |
+ VID_DATATYPE(MIPI_DSI_PACKED_PIXEL_STREAM_18);
+ break;
+
+ case MIPI_DSI_FMT_RGB565:
+ tmp = VID_PIXEL_MODE_RGB666_PACKED |
+ VID_DATATYPE(MIPI_DSI_PACKED_PIXEL_STREAM_16);
+ break;
+
+ default:
+ dev_err(dsi->base.dev, "Unsupported DSI format\n");
+ return;
+ }
+
+ if (output->dev->mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE)
+ tmp |= SYNC_PULSE_ACTIVE | SYNC_PULSE_HORIZONTAL;
+
+ tmp |= REG_BLKLINE_MODE(REG_BLK_MODE_BLANKING_PKT) |
+ REG_BLKEOL_MODE(REG_BLK_MODE_BLANKING_PKT) |
+ RECOVERY_MODE(RECOVERY_MODE_NEXT_HSYNC);
+
+ writel(tmp, dsi->regs + VID_MAIN_CTL);
+ }
+
+ tmp = readl(dsi->regs + MCTL_MAIN_DATA_CTL);
+ tmp &= ~(IF_VID_SELECT_MASK | HOST_EOT_GEN | IF_VID_MODE);
+
+ if (!(output->dev->mode_flags & MIPI_DSI_MODE_EOT_PACKET))
+ tmp |= HOST_EOT_GEN;
+
+ if (output->dev->mode_flags & MIPI_DSI_MODE_VIDEO)
+ tmp |= IF_VID_MODE | IF_VID_SELECT(input->id) | VID_EN;
+
+ writel(tmp, dsi->regs + MCTL_MAIN_DATA_CTL);
+
+ tmp = readl(dsi->regs + MCTL_MAIN_EN) | IF_EN(input->id);
+ writel(tmp, dsi->regs + MCTL_MAIN_EN);
+}
+
+static const struct drm_bridge_funcs cdns_dsi_bridge_funcs = {
+ .attach = cdns_dsi_bridge_attach,
+ .mode_valid = cdns_dsi_bridge_mode_valid,
+ .disable = cdns_dsi_bridge_disable,
+ .enable = cdns_dsi_bridge_enable,
+};
+
+static int cdns_dsi_init_link(struct cdns_dsi *dsi)
+{
+ struct cdns_dsi_output *output = &dsi->output;
+ unsigned long sysclk_period, ulpout;
+ u32 val;
+ int i;
+
+ writel(0, dsi->regs + MCTL_DPHY_STATIC);
+
+ val = 0;
+ for (i = 1; i < output->dev->lanes; i++)
+ val |= DATA_LANE_EN(i);
+
+ if (!(output->dev->mode_flags & MIPI_DSI_CLOCK_NON_CONTINUOUS))
+ val |= CLK_CONTINUOUS;
+
+ writel(val, dsi->regs + MCTL_MAIN_PHY_CTL);
+
+ /* ULPOUT should be set to 1ms and is expressed in sysclk cycles. */
+ sysclk_period = NSEC_PER_SEC / clk_get_rate(dsi->sysclk);
+ ulpout = DIV_ROUND_UP(NSEC_PER_MSEC, sysclk_period);
+ writel(CLK_LANE_ULPOUT_TIME(ulpout) | DATA_LANE_ULPOUT_TIME(ulpout),
+ dsi->regs + MCTL_ULPOUT_TIME);
+
+ writel(LINK_EN, dsi->regs + MCTL_MAIN_DATA_CTL);
+
+ val = CLK_LANE_EN | PLL_START;
+ for (i = 0; i < output->dev->lanes; i++)
+ val |= DATA_LANE_START(i);
+
+ writel(val, dsi->regs + MCTL_MAIN_EN);
+
+ ndelay(100);
+
+ return 0;
+}
+
+static int cdns_dsi_attach(struct mipi_dsi_host *host,
+ struct mipi_dsi_device *dev)
+{
+ struct cdns_dsi *dsi = to_cdns_dsi(host);
+ struct cdns_dsi_output *output = &dsi->output;
+ struct cdns_dsi_input *input = &dsi->input;
+ struct drm_bridge *bridge;
+ struct drm_panel *panel;
+ struct device_node *np;
+ int ret;
+
+ /*
+ * We currently do not support connecting several DSI devices to the
+ * same host. In order to support that we'd need the DRM bridge
+ * framework to allow dynamic reconfiguration of the bridge chain.
+ */
+ if (output->dev)
+ return -EBUSY;
+
+ /* We do not support burst mode yet. */
+ if (dev->mode_flags & MIPI_DSI_MODE_VIDEO_BURST)
+ return -ENOTSUPP;
+
+ /*
+ * The host <-> device link might be described using an OF-graph
+ * representation, in this case we extract the device of_node from
+ * this representation, otherwise we use dsidev->dev.of_node which
+ * should have been filled by the core.
+ */
+ np = of_graph_get_remote_node(dsi->base.dev->of_node, DSI_OUTPUT_PORT,
+ dev->channel);
+ if (!np)
+ np = of_node_get(dev->dev.of_node); > +
+ panel = of_drm_find_panel(np);
+ if (panel) {
+ bridge = drm_panel_bridge_add(panel, DRM_MODE_CONNECTOR_DSI);
+ } else {
+ bridge = of_drm_find_bridge(dev->dev.of_node);
+ if (!bridge)
+ bridge = ERR_PTR(-EINVAL);
+ }
+
+ of_node_put(np);
It would have been nice to use drm_of_find_panel_or_bridge() here, but I guess
you couldn't use it because you have to handle both OF-graph based links, and
children directly under the host DSI bus.
The patch looks good to me otherwise.
Thanks,
Archit
+
+ if (IS_ERR(bridge)) {
+ ret = PTR_ERR(bridge);
+ dev_err(host->dev, "failed to add DSI device %s (err = %d)",
+ dev->name, ret);
+ return ret;
+ }
+
+ output->dev = dev;
+ output->bridge = bridge;
+ output->panel = panel;
+
+ ret = cdns_dsi_init_link(dsi);
+ if (ret)
+ goto err_rst_output;
+
+ /*
+ * The DSI output has been properly configured, we can now safely
+ * register the input to the bridge framework so that it can take place
+ * in a display pipeline.
+ */
+ drm_bridge_add(&input->bridge);
+
+ return 0;
+
+err_rst_output:
+ if (panel)
+ drm_panel_bridge_remove(bridge);
+
+ output->bridge = NULL;
+ output->panel = NULL;
+ output->dev = NULL;
+
+ return ret;
+}
<snip>
--
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a Linux Foundation Collaborative Project
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