Le 26/07/2024 à 21:44, Alex Lanzano a écrit :
Add support for the monochrome Sharp Memory LCDs.
Signed-off-by: Alex Lanzano
<lanzano.alex-re5jqeeqqe8avxtiumw...@public.gmane.org>
Co-developed-by: Mehdi Djait
<mehdi.djait-ldxbnhwyfcjbdgjk7y7...@public.gmane.org>
Signed-off-by: Mehdi Djait <mehdi.djait-ldxbnhwyfcjbdgjk7y7...@public.gmane.org>
---
MAINTAINERS | 7 +
drivers/gpu/drm/tiny/Kconfig | 20 +
drivers/gpu/drm/tiny/Makefile | 1 +
drivers/gpu/drm/tiny/sharp-memory.c | 726 ++++++++++++++++++++++++++++
4 files changed, 754 insertions(+)
create mode 100644 drivers/gpu/drm/tiny/sharp-memory.c
Hi,
below some other tiny comments, hoping it helps.
Also "./scripts/checkpatch.pl --strict" gives some hints, should some be
of interest.
+static int sharp_memory_probe(struct spi_device *spi)
+{
+ int ret;
+ struct device *dev;
+ struct sharp_memory_device *smd;
+ enum sharp_memory_model model;
+ struct drm_device *drm;
+ const char *vcom_mode_str;
+
+ ret = spi_setup(spi);
+ if (ret < 0)
+ return dev_err_probe(&spi->dev, ret, "Failed to setup spi
device\n");
+
+ dev = &spi->dev;
6 times below, &spi->dev could be replaced by dev, to slightly simplify
things.
+ if (!dev->coherent_dma_mask) {
+ ret = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(32));
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to set dma
mask\n");
+ }
+
+ smd = devm_drm_dev_alloc(&spi->dev, &sharp_memory_drm_driver,
+ struct sharp_memory_device, drm);
Missing error handling.
+
+ spi_set_drvdata(spi, smd);
+
+ smd->spi = spi;
+ drm = &smd->drm;
+ ret = drmm_mode_config_init(drm);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to initialize drm
config\n");
+
+ smd->enable_gpio = devm_gpiod_get_optional(dev, "enable",
GPIOD_OUT_HIGH);
+ if (smd->enable_gpio == NULL)
Nitpick: if (!smd->enable_gpio)
+ dev_warn(&spi->dev, "Enable gpio not defined\n");
+
+ /*
+ * VCOM is a signal that prevents DC bias from being built up in
+ * the panel resulting in pixels being forever stuck in one state.
+ *
+ * This driver supports three different methods to generate this
+ * signal depending on EXTMODE pin:
+ *
+ * software (EXTMODE = L) - This mode uses a kthread to
+ * periodically send a "maintain display" message to the display,
+ * toggling the vcom bit on and off with each message
+ *
+ * external (EXTMODE = H) - This mode relies on an external
+ * clock to generate the signal on the EXTCOMM pin
+ *
+ * pwm (EXTMODE = H) - This mode uses a pwm device to generate
+ * the signal on the EXTCOMM pin
+ *
+ */
+ smd->vcom = 0;
Nitpick: devm_drm_dev_alloc() already zeroes the allocated memory. So
this is useless. Unless you think it gives some useful hint, it could be
removed.
+ if (device_property_read_string(&spi->dev, "vcom-mode", &vcom_mode_str))
+ return dev_err_probe(dev, -EINVAL,
+ "Unable to find vcom-mode node in device
tree\n");
+
+ if (!strcmp("software", vcom_mode_str)) {
+ smd->vcom_mode = SHARP_MEMORY_SOFTWARE_VCOM;
...
+ smd->pitch = (SHARP_ADDR_PERIOD + smd->mode->hdisplay +
SHARP_DUMMY_PERIOD) / 8;
+ smd->tx_buffer_size = (SHARP_MODE_PERIOD +
+ (SHARP_ADDR_PERIOD + (smd->mode->hdisplay) +
SHARP_DUMMY_PERIOD) *
+ smd->mode->vdisplay) / 8;
+
+ smd->tx_buffer = devm_kzalloc(&spi->dev, smd->tx_buffer_size,
GFP_KERNEL);
+ if (!smd->tx_buffer)
+ return dev_err_probe(&spi->dev, -ENOMEM, "Unable to alloc tx
buffer\n");
There is no need to log a message for memory allocation failure.
return -ENOMEM; should be just fine IMHO.
+
+ mutex_init(&smd->tx_mutex);
+
+ drm->mode_config.min_width = smd->mode->hdisplay;
+ drm->mode_config.max_width = smd->mode->hdisplay;
+ drm->mode_config.min_height = smd->mode->vdisplay;
+ drm->mode_config.max_height = smd->mode->vdisplay;
+
+ ret = sharp_memory_pipe_init(drm, smd,
+ sharp_memory_formats,
Nitpick: you could save 1 LoC if this is put at the end of the previous
line.
+ ARRAY_SIZE(sharp_memory_formats),
+ NULL);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to initialize display
pipeline.\n");
+
+ drm_plane_enable_fb_damage_clips(&smd->plane);
+ drm_mode_config_reset(drm);
+
+ ret = drm_dev_register(drm, 0);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to register drm
device.\n");
+
+ drm_fbdev_dma_setup(drm, 0);
+
+ return 0;
+}
...
CJ
