Re: [PATCH v18 3/3] drm/ingenic: Add dw-hdmi driver specialization for jz4780

From: Neil Armstrong
Date: Mon Apr 11 2022 - 10:24:36 EST


On 07/04/2022 13:16, H. Nikolaus Schaller wrote:
From: Paul Boddie <paul@xxxxxxxxxxxxx>

A specialisation of the generic Synopsys HDMI driver is employed for
JZ4780 HDMI support. This requires a new driver, plus device tree and
configuration modifications.

Here we add Kconfig DRM_INGENIC_DW_HDMI, Makefile and driver code.

Note that there is no hpd-gpio installed on the CI20 board HDMI
connector. Hence there is no hpd detection by the connector driver
and we have to enable polling in the dw-hdmi core driver.

For that we need to set .poll_enabled but that struct component
can only be accessed by core code. Hence we use the public
setter function drm_kms_helper_hotplug_event() introduced before.

Also note that we disable Color Space Conversion since it is not
working on jz4780.

Signed-off-by: Paul Boddie <paul@xxxxxxxxxxxxx>
Signed-off-by: Ezequiel Garcia <ezequiel@xxxxxxxxxxxxx>
Signed-off-by: H. Nikolaus Schaller <hns@xxxxxxxxxxxxx>
---
drivers/gpu/drm/ingenic/Kconfig | 9 ++
drivers/gpu/drm/ingenic/Makefile | 1 +
drivers/gpu/drm/ingenic/ingenic-dw-hdmi.c | 103 ++++++++++++++++++++++
3 files changed, 113 insertions(+)
create mode 100644 drivers/gpu/drm/ingenic/ingenic-dw-hdmi.c

diff --git a/drivers/gpu/drm/ingenic/Kconfig b/drivers/gpu/drm/ingenic/Kconfig
index 001f59fb06d56..090830bcbde7f 100644
--- a/drivers/gpu/drm/ingenic/Kconfig
+++ b/drivers/gpu/drm/ingenic/Kconfig
@@ -24,4 +24,13 @@ config DRM_INGENIC_IPU
The Image Processing Unit (IPU) will appear as a second primary plane.
+config DRM_INGENIC_DW_HDMI
+ tristate "Ingenic specific support for Synopsys DW HDMI"
+ depends on MACH_JZ4780
+ select DRM_DW_HDMI
+ help
+ Choose this option to enable Synopsys DesignWare HDMI based driver.
+ If you want to enable HDMI on Ingenic JZ4780 based SoC, you should
+ select this option.
+
endif
diff --git a/drivers/gpu/drm/ingenic/Makefile b/drivers/gpu/drm/ingenic/Makefile
index d313326bdddbb..f10cc1c5a5f22 100644
--- a/drivers/gpu/drm/ingenic/Makefile
+++ b/drivers/gpu/drm/ingenic/Makefile
@@ -1,3 +1,4 @@
obj-$(CONFIG_DRM_INGENIC) += ingenic-drm.o
ingenic-drm-y = ingenic-drm-drv.o
ingenic-drm-$(CONFIG_DRM_INGENIC_IPU) += ingenic-ipu.o
+obj-$(CONFIG_DRM_INGENIC_DW_HDMI) += ingenic-dw-hdmi.o
diff --git a/drivers/gpu/drm/ingenic/ingenic-dw-hdmi.c b/drivers/gpu/drm/ingenic/ingenic-dw-hdmi.c
new file mode 100644
index 0000000000000..72f8b44998a51
--- /dev/null
+++ b/drivers/gpu/drm/ingenic/ingenic-dw-hdmi.c
@@ -0,0 +1,103 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 2011-2013 Freescale Semiconductor, Inc.
+ * Copyright (C) 2019, 2020 Paul Boddie <paul@xxxxxxxxxxxxx>
+ *
+ * Derived from dw_hdmi-imx.c with i.MX portions removed.
+ */
+
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+
+#include <drm/bridge/dw_hdmi.h>
+#include <drm/drm_of.h>
+#include <drm/drm_print.h>
+
+static const struct dw_hdmi_mpll_config ingenic_mpll_cfg[] = {
+ { 45250000, { { 0x01e0, 0x0000 }, { 0x21e1, 0x0000 }, { 0x41e2, 0x0000 } } },
+ { 92500000, { { 0x0140, 0x0005 }, { 0x2141, 0x0005 }, { 0x4142, 0x0005 } } },
+ { 148500000, { { 0x00a0, 0x000a }, { 0x20a1, 0x000a }, { 0x40a2, 0x000a } } },
+ { 216000000, { { 0x00a0, 0x000a }, { 0x2001, 0x000f }, { 0x4002, 0x000f } } },
+ { ~0UL, { { 0x0000, 0x0000 }, { 0x0000, 0x0000 }, { 0x0000, 0x0000 } } }
+};
+
+static const struct dw_hdmi_curr_ctrl ingenic_cur_ctr[] = {
+ /*pixelclk bpp8 bpp10 bpp12 */
+ { 54000000, { 0x091c, 0x091c, 0x06dc } },
+ { 58400000, { 0x091c, 0x06dc, 0x06dc } },
+ { 72000000, { 0x06dc, 0x06dc, 0x091c } },
+ { 74250000, { 0x06dc, 0x0b5c, 0x091c } },
+ { 118800000, { 0x091c, 0x091c, 0x06dc } },
+ { 216000000, { 0x06dc, 0x0b5c, 0x091c } },
+ { ~0UL, { 0x0000, 0x0000, 0x0000 } },
+};
+
+/*
+ * Resistance term 133Ohm Cfg
+ * PREEMP config 0.00
+ * TX/CK level 10
+ */
+static const struct dw_hdmi_phy_config ingenic_phy_config[] = {
+ /*pixelclk symbol term vlev */
+ { 216000000, 0x800d, 0x0005, 0x01ad},
+ { ~0UL, 0x0000, 0x0000, 0x0000}
+};
+
+static enum drm_mode_status
+ingenic_dw_hdmi_mode_valid(struct dw_hdmi *hdmi, void *data,
+ const struct drm_display_info *info,
+ const struct drm_display_mode *mode)
+{
+ if (mode->clock < 13500)
+ return MODE_CLOCK_LOW;
+ /* FIXME: Hardware is capable of 270MHz, but setup data is missing. */
+ if (mode->clock > 216000)
+ return MODE_CLOCK_HIGH;
+
+ return MODE_OK;
+}
+
+static struct dw_hdmi_plat_data ingenic_dw_hdmi_plat_data = {
+ .mpll_cfg = ingenic_mpll_cfg,
+ .cur_ctr = ingenic_cur_ctr,
+ .phy_config = ingenic_phy_config,
+ .mode_valid = ingenic_dw_hdmi_mode_valid,
+ .output_port = 1,
+};
+
+static const struct of_device_id ingenic_dw_hdmi_dt_ids[] = {
+ { .compatible = "ingenic,jz4780-dw-hdmi" },
+ { /* Sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, ingenic_dw_hdmi_dt_ids);
+
+static void ingenic_dw_hdmi_cleanup(void *data)
+{
+ struct dw_hdmi *hdmi = (struct dw_hdmi *)data;
+
+ dw_hdmi_remove(hdmi);
+}
+
+static int ingenic_dw_hdmi_probe(struct platform_device *pdev)
+{
+ struct dw_hdmi *hdmi;
+
+ hdmi = dw_hdmi_probe(pdev, &ingenic_dw_hdmi_plat_data);
+ if (IS_ERR(hdmi))
+ return PTR_ERR(hdmi);
+
+ return devm_add_action_or_reset(&pdev->dev, ingenic_dw_hdmi_cleanup, hdmi);
+}
+
+static struct platform_driver ingenic_dw_hdmi_driver = {
+ .probe = ingenic_dw_hdmi_probe,
+ .driver = {
+ .name = "dw-hdmi-ingenic",
+ .of_match_table = ingenic_dw_hdmi_dt_ids,
+ },
+};
+module_platform_driver(ingenic_dw_hdmi_driver);
+
+MODULE_DESCRIPTION("JZ4780 Specific DW-HDMI Driver Extension");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:dw-hdmi-ingenic");

Looks fine, LGTM now we figured out all the details !

Reviewed-by: Neil Armstrong <narmstrong@xxxxxxxxxxxx>