Re: [PATCH 2/2] drm/panel: add BOE tv101wum-ll2 panel driver
From: Neil Armstrong
Date: Wed Jul 24 2024 - 03:51:09 EST
On 23/07/2024 21:17, Doug Anderson wrote:
Hi,
On Tue, Jul 9, 2024 at 6:06 AM Neil Armstrong <neil.armstrong@xxxxxxxxxx> wrote:
diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile
index 5581387707c6..79c90894b6a4 100644
--- a/drivers/gpu/drm/panel/Makefile
+++ b/drivers/gpu/drm/panel/Makefile
@@ -7,6 +7,7 @@ obj-$(CONFIG_DRM_PANEL_BOE_BF060Y8M_AJ0) += panel-boe-bf060y8m-aj0.o
obj-$(CONFIG_DRM_PANEL_BOE_HIMAX8279D) += panel-boe-himax8279d.o
obj-$(CONFIG_DRM_PANEL_BOE_TH101MB31UIG002_28A) += panel-boe-th101mb31ig002-28a.o
obj-$(CONFIG_DRM_PANEL_BOE_TV101WUM_NL6) += panel-boe-tv101wum-nl6.o
+obj-$(CONFIG_DRM_PANEL_BOE_TV101WUM_LL2) += panel-boe-tv101wum-ll2.o
nit: please sort. L comes before N.
Good catch, thx
obj-$(CONFIG_DRM_PANEL_DSI_CM) += panel-dsi-cm.o
obj-$(CONFIG_DRM_PANEL_LVDS) += panel-lvds.o
obj-$(CONFIG_DRM_PANEL_SIMPLE) += panel-simple.o
diff --git a/drivers/gpu/drm/panel/panel-boe-tv101wum-ll2.c b/drivers/gpu/drm/panel/panel-boe-tv101wum-ll2.c
new file mode 100644
index 000000000000..5513cb48d949
--- /dev/null
+++ b/drivers/gpu/drm/panel/panel-boe-tv101wum-ll2.c
@@ -0,0 +1,240 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Generated with linux-mdss-dsi-panel-driver-generator from vendor device tree:
+// Copyright (c) 2013, The Linux Foundation. All rights reserved.
+// Copyright (c) 2024, Neil Armstrong <neil.armstrong@xxxxxxxxxx>
+
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/regulator/consumer.h>
+#include <linux/module.h>
+#include <linux/of.h>
nit: sort header files?
Will do while I'm it, but I don't personally care of the include order..
+static int boe_tv101wum_ll2_prepare(struct drm_panel *panel)
+{
+ struct boe_tv101wum_ll2 *ctx = to_boe_tv101wum_ll2(panel);
+ struct device *dev = &ctx->dsi->dev;
+ int ret;
+
+ ret = regulator_bulk_enable(ARRAY_SIZE(ctx->supplies),
+ ctx->supplies);
+ if (ret < 0)
+ return ret;
+
+ boe_tv101wum_ll2_reset(ctx);
+
+ ret = boe_tv101wum_ll2_on(ctx);
+ if (ret < 0) {
+ dev_err(dev, "Failed to initialize panel: %d\n", ret);
nit: Do you really need this error message? The "_multi" variants are
all chatty and print the error message, so we don't really need this
here...
Yeah you're right, it's a leftover of the linux-mdss-dsi-panel-driver-generator
+ gpiod_set_value_cansleep(ctx->reset_gpio, 1);
+ return ret;
Shouldn't you turn off the regulators?
Indeed
+static int boe_tv101wum_ll2_unprepare(struct drm_panel *panel)
+{
+ struct boe_tv101wum_ll2 *ctx = to_boe_tv101wum_ll2(panel);
+ struct device *dev = &ctx->dsi->dev;
+ int ret;
+
+ ret = boe_tv101wum_ll2_off(ctx);
+ if (ret < 0)
+ dev_err(dev, "Failed to un-initialize panel: %d\n", ret);
nit: Do you really need this error message? The "_multi" variants are
all chatty and print the error message, so we don't really need this
here...
Another leftover
+
+ gpiod_set_value_cansleep(ctx->reset_gpio, 1);
+
+ regulator_bulk_disable(ARRAY_SIZE(ctx->supplies), ctx->supplies);
+
+ return 0;
Maybe add a comment justifying why you don't return the error code
that boe_tv101wum_ll2_off() returned?
Good point, as far as I remember I always avoided returning errors
when disabling things, I'll investigate
+static int boe_tv101wum_ll2_get_modes(struct drm_panel *panel,
+ struct drm_connector *connector)
+{
+ return drm_connector_helper_get_modes_fixed(connector, &boe_tv101wum_ll2_mode);
Random question for you: on panels that don't use the
drm_connector_helper the "bpc" gets set here. Is there a reason why
some panel drivers (like this one) don't set bpc?
Good question, I'll check
+static int boe_tv101wum_ll2_probe(struct mipi_dsi_device *dsi)
+{
+ struct device *dev = &dsi->dev;
+ struct boe_tv101wum_ll2 *ctx;
+ int ret;
+
+ ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
+ if (!ctx)
+ return -ENOMEM;
+
+ ctx->supplies[0].supply = "vsp";
+ ctx->supplies[1].supply = "vsn";
+
+ ret = devm_regulator_bulk_get(&dsi->dev, ARRAY_SIZE(ctx->supplies),
+ ctx->supplies);
Any chance I can convince you to use devm_regulator_bulk_get_const()?
Then you can list your supply structures as "static const" instead of
having to initialize them via code.
You convinced me!
+ if (ret < 0)
+ return ret;
+
+ ctx->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
+ if (IS_ERR(ctx->reset_gpio))
+ return dev_err_probe(dev, PTR_ERR(ctx->reset_gpio),
+ "Failed to get reset-gpios\n");
+
+ ctx->dsi = dsi;
+ mipi_dsi_set_drvdata(dsi, ctx);
+
+ dsi->lanes = 4;
+ dsi->format = MIPI_DSI_FMT_RGB888;
+ dsi->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_BURST |
+ MIPI_DSI_MODE_VIDEO_HSE;
+
+ drm_panel_init(&ctx->panel, dev, &boe_tv101wum_ll2_panel_funcs,
+ DRM_MODE_CONNECTOR_DSI);
+ ctx->panel.prepare_prev_first = true;
+
+ ret = drm_panel_of_backlight(&ctx->panel);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to get backlight\n");
+
+ drm_panel_add(&ctx->panel);
Any chance you could add devm_drm_panel_add() and then use it? Then
you can fully get rid of your remove and error handling since
devm_mipi_dsi_attach() already exists. Note that this would not change
object lifetimes at all since you're already calling
drm_panel_remove() in your remove code--it would just clean up the
code...
Yep I'll use it
+static struct mipi_dsi_driver boe_tv101wum_ll2_driver = {
+ .probe = boe_tv101wum_ll2_probe,
+ .remove = boe_tv101wum_ll2_remove,
+ .driver = {
+ .name = "panel-boe-tv101wum_ll2",
+ .of_match_table = boe_tv101wum_ll2_of_match,
+ },
+};
+module_mipi_dsi_driver(boe_tv101wum_ll2_driver);
+
+MODULE_DESCRIPTION("DRM driver for Boe TV101WUM-LL2 Panel");
Should "Boe" be "BOE" ?
Good point aswell!
Thanks for the review
Neil