[PATCH v9 2/2] drm/tiny: Add driver for Sharp Memory LCD

Alex Lanzano
2024-10-07T01:31:35Z

Add support for the monochrome Sharp Memory LCDs.

Co-developed-by: Mehdi Djait <mehdi.djait@bootlin.com>
Signed-off-by: Mehdi Djait <mehdi.djait@bootlin.com>
Signed-off-by: Alex Lanzano <lanzano.alex@gmail.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
MAINTAINERS | 6 +
drivers/gpu/drm/tiny/Kconfig | 20 +
drivers/gpu/drm/tiny/Makefile | 1 +
drivers/gpu/drm/tiny/sharp-memory.c | 666 ++++++++++++++++++++++++++++
4 files changed, 693 insertions(+)
create mode 100644 drivers/gpu/drm/tiny/sharp-memory.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 5432239f3c5d..f3b1a6115711 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7289,6 +7289,12 @@ S: Maintained
F: Documentation/devicetree/bindings/display/panel/samsung,s6d7aa0.yaml
F: drivers/gpu/drm/panel/panel-samsung-s6d7aa0.c

+DRM DRIVER FOR SHARP MEMORY LCD
+M: Alex Lanzano <lanzano.alex@gmail.com>
+S: Maintained
+F: Documentation/devicetree/bindings/display/sharp,ls010b7dh04.yaml
+F: drivers/gpu/drm/tiny/sharp-memory.c
+
DRM DRIVER FOR SITRONIX ST7586 PANELS
M: David Lechner <david@lechnology.com>
S: Maintained
diff --git a/drivers/gpu/drm/tiny/Kconfig b/drivers/gpu/drm/tiny/Kconfig
index f6889f649bc1..bc386954faa2 100644
--- a/drivers/gpu/drm/tiny/Kconfig
+++ b/drivers/gpu/drm/tiny/Kconfig
@@ -186,6 +186,26 @@ config TINYDRM_REPAPER

If M is selected the module will be called repaper.

+config TINYDRM_SHARP_MEMORY
+ tristate "DRM support for Sharp Memory LCD panels"
+ depends on DRM && SPI
+ select DRM_GEM_DMA_HELPER
+ select DRM_KMS_HELPER
+ help
+ DRM Driver for the following Sharp Memory Panels:
+ * 1.00" Sharp Memory LCD (LS010B7DH04)
+ * 1.10" Sharp Memory LCD (LS011B7DH03)
+ * 1.20" Sharp Memory LCD (LS012B7DD01)
+ * 1.28" Sharp Memory LCD (LS013B7DH03)
+ * 1.26" Sharp Memory LCD (LS013B7DH05)
+ * 1.80" Sharp Memory LCD (LS018B7DH02)
+ * 2.70" Sharp Memory LCD (LS027B7DH01)
+ * 2.70" Sharp Memory LCD (LS027B7DH01A)
+ * 3.20" Sharp Memory LCD (LS032B7DD02)
+ * 4.40" Sharp Memory LCD (LS044Q7DH01)
+
+ If M is selected the module will be called sharp_memory.
+
config TINYDRM_ST7586
tristate "DRM support for Sitronix ST7586 display panels"
depends on DRM && SPI
diff --git a/drivers/gpu/drm/tiny/Makefile b/drivers/gpu/drm/tiny/Makefile
index 76dde89a044b..4aaf56f8707d 100644
--- a/drivers/gpu/drm/tiny/Makefile
+++ b/drivers/gpu/drm/tiny/Makefile
@@ -14,5 +14,6 @@ obj-$(CONFIG_TINYDRM_ILI9341) += ili9341.o
obj-$(CONFIG_TINYDRM_ILI9486) += ili9486.o
obj-$(CONFIG_TINYDRM_MI0283QT) += mi0283qt.o
obj-$(CONFIG_TINYDRM_REPAPER) += repaper.o
+obj-$(CONFIG_TINYDRM_SHARP_MEMORY) += sharp-memory.o
obj-$(CONFIG_TINYDRM_ST7586) += st7586.o
obj-$(CONFIG_TINYDRM_ST7735R) += st7735r.o
diff --git a/drivers/gpu/drm/tiny/sharp-memory.c b/drivers/gpu/drm/tiny/sharp-memory.c
new file mode 100644
index 000000000000..397b305cce38
--- /dev/null
+++ b/drivers/gpu/drm/tiny/sharp-memory.c
@@ -0,0 +1,666 @@
+// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+
+#include <drm/drm_atomic.h>
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_connector.h>
+#include <drm/drm_damage_helper.h>
+#include <drm/drm_drv.h>
+#include <drm/drm_fb_dma_helper.h>
+#include <drm/drm_fbdev_dma.h>
+#include <drm/drm_format_helper.h>
+#include <drm/drm_framebuffer.h>
+#include <drm/drm_gem_atomic_helper.h>
+#include <drm/drm_gem_dma_helper.h>
+#include <drm/drm_gem_framebuffer_helper.h>
+#include <drm/drm_managed.h>
+#include <drm/drm_modes.h>
+#include <drm/drm_probe_helper.h>
+#include <drm/drm_rect.h>
+#include <linux/bitrev.h>
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/kthread.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/pwm.h>
+#include <linux/spi/spi.h>
+
+#define SHARP_MODE_PERIOD 8
+#define SHARP_ADDR_PERIOD 8
+#define SHARP_DUMMY_PERIOD 8
+
+#define SHARP_MEMORY_DISPLAY_MAINTAIN_MODE 0
+#define SHARP_MEMORY_DISPLAY_UPDATE_MODE 1
+#define SHARP_MEMORY_DISPLAY_CLEAR_MODE 4
+
+enum sharp_memory_model {
+ LS010B7DH04,
+ LS011B7DH03,
+ LS012B7DD01,
+ LS013B7DH03,
+ LS013B7DH05,
+ LS018B7DH02,
+ LS027B7DH01,
+ LS027B7DH01A,
+ LS032B7DD02,
+ LS044Q7DH01,
+};
+
+enum sharp_memory_vcom_mode {
+ SHARP_MEMORY_SOFTWARE_VCOM,
+ SHARP_MEMORY_EXTERNAL_VCOM,
+ SHARP_MEMORY_PWM_VCOM
+};
+
+struct sharp_memory_device {
+ struct drm_device drm;
+ struct spi_device *spi;
+
+ const struct drm_display_mode *mode;
+
+ struct drm_crtc crtc;
+ struct drm_plane plane;
+ struct drm_encoder encoder;
+ struct drm_connector connector;
+
+ struct gpio_desc *enable_gpio;
+
+ struct task_struct *sw_vcom_signal;
+ struct pwm_device *pwm_vcom_signal;
+
+ enum sharp_memory_vcom_mode vcom_mode;
+ u8 vcom;
+
+ u32 pitch;
+ u32 tx_buffer_size;
+ u8 *tx_buffer;
+
+ /* When vcom_mode == "software" a kthread is used to periodically send a
+ * 'maintain display' message over spi. This mutex ensures tx_buffer access
+ * and spi bus usage is synchronized in this case.
+ */
+ struct mutex tx_mutex;
+};
+
+static inline int sharp_memory_spi_write(struct spi_device *spi, void *buf, size_t len)
+{
+ /* Reverse the bit order */
+ for (u8 *b = buf; b < ((u8 *)buf) + len; ++b)
+ *b = bitrev8(*b);
+
+ return spi_write(spi, buf, len);
+}
+
+static inline struct sharp_memory_device *drm_to_sharp_memory_device(struct drm_device *drm)
+{
+ return container_of(drm, struct sharp_memory_device, drm);
+}
+
+DEFINE_DRM_GEM_DMA_FOPS(sharp_memory_fops);
+
+static const struct drm_driver sharp_memory_drm_driver = {
+ .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
+ .fops = &sharp_memory_fops,
+ DRM_GEM_DMA_DRIVER_OPS_VMAP,
+ .name = "sharp_memory_display",
+ .desc = "Sharp Display Memory LCD",
+ .date = "20231129",
+ .major = 1,
+ .minor = 0,
+};
+
+static inline void sharp_memory_set_tx_buffer_mode(u8 *buffer, u8 mode, u8 vcom)
+{
+ *buffer = mode | (vcom << 1);
+}
+
+static inline void sharp_memory_set_tx_buffer_addresses(u8 *buffer,
+ struct drm_rect clip,
+ u32 pitch)
+{
+ for (u32 line = 0; line < clip.y2; ++line)
+ buffer[line * pitch] = line + 1;
+}
+
+static void sharp_memory_set_tx_buffer_data(u8 *buffer,
+ struct drm_framebuffer *fb,
+ struct drm_rect clip,
+ u32 pitch,
+ struct drm_format_conv_state *fmtcnv_state)
+{
+ int ret;
+ struct iosys_map dst, vmap;
+ struct drm_gem_dma_object *dma_obj = drm_fb_dma_get_gem_obj(fb, 0);
+
+ ret = drm_gem_fb_begin_cpu_access(fb, DMA_FROM_DEVICE);
+ if (ret)
+ return;
+
+ iosys_map_set_vaddr(&dst, buffer);
+ iosys_map_set_vaddr(&vmap, dma_obj->vaddr);
+
+ drm_fb_xrgb8888_to_mono(&dst, &pitch, &vmap, fb, &clip, fmtcnv_state);
+
+ drm_gem_fb_end_cpu_access(fb, DMA_FROM_DEVICE);
+}
+
+static int sharp_memory_update_display(struct sharp_memory_device *smd,
+ struct drm_framebuffer *fb,
+ struct drm_rect clip,
+ struct drm_format_conv_state *fmtcnv_state)
+{
+ int ret;
+ u32 pitch = smd->pitch;
+ u8 vcom = smd->vcom;
+ u8 *tx_buffer = smd->tx_buffer;
+ u32 tx_buffer_size = smd->tx_buffer_size;
+
+ mutex_lock(&smd->tx_mutex);
+
+ /* Populate the transmit buffer with frame data */
+ sharp_memory_set_tx_buffer_mode(&tx_buffer[0],
+ SHARP_MEMORY_DISPLAY_UPDATE_MODE, vcom);
+ sharp_memory_set_tx_buffer_addresses(&tx_buffer[1], clip, pitch);
+ sharp_memory_set_tx_buffer_data(&tx_buffer[2], fb, clip, pitch, fmtcnv_state);
+
+ ret = sharp_memory_spi_write(smd->spi, tx_buffer, tx_buffer_size);
+
+ mutex_unlock(&smd->tx_mutex);
+
+ return ret;
+}
+
+static int sharp_memory_maintain_display(struct sharp_memory_device *smd)
+{
+ int ret;
+ u8 vcom = smd->vcom;
+ u8 *tx_buffer = smd->tx_buffer;
+
+ mutex_lock(&smd->tx_mutex);
+
+ sharp_memory_set_tx_buffer_mode(&tx_buffer[0], SHARP_MEMORY_DISPLAY_MAINTAIN_MODE, vcom);
+ tx_buffer[1] = 0; /* Write dummy data */
+ ret = sharp_memory_spi_write(smd->spi, tx_buffer, 2);
+
+ mutex_unlock(&smd->tx_mutex);
+
+ return ret;
+}
+
+static int sharp_memory_clear_display(struct sharp_memory_device *smd)
+{
+ int ret;
+ u8 vcom = smd->vcom;
+ u8 *tx_buffer = smd->tx_buffer;
+
+ mutex_lock(&smd->tx_mutex);
+
+ sharp_memory_set_tx_buffer_mode(&tx_buffer[0], SHARP_MEMORY_DISPLAY_CLEAR_MODE, vcom);
+ tx_buffer[1] = 0; /* write dummy data */
+ ret = sharp_memory_spi_write(smd->spi, tx_buffer, 2);
+
+ mutex_unlock(&smd->tx_mutex);
+
+ return ret;
+}
+
+static void sharp_memory_fb_dirty(struct drm_framebuffer *fb, struct drm_rect *rect,
+ struct drm_format_conv_state *fmtconv_state)
+{
+ struct drm_rect clip;
+ struct sharp_memory_device *smd = drm_to_sharp_memory_device(fb->dev);
+
+ /* Always update a full line regardless of what is dirty */
+ clip.x1 = 0;
+ clip.x2 = fb->width;
+ clip.y1 = rect->y1;
+ clip.y2 = rect->y2;
+
+ sharp_memory_update_display(smd, fb, clip, fmtconv_state);
+}
+
+static int sharp_memory_plane_atomic_check(struct drm_plane *plane,
+ struct drm_atomic_state *state)
+{
+ struct drm_plane_state *plane_state = drm_atomic_get_new_plane_state(state, plane);
+ struct sharp_memory_device *smd;
+ struct drm_crtc_state *crtc_state;
+
+ smd = container_of(plane, struct sharp_memory_device, plane);
+ crtc_state = drm_atomic_get_new_crtc_state(state, &smd->crtc);
+
+ return drm_atomic_helper_check_plane_state(plane_state, crtc_state,
+ DRM_PLANE_NO_SCALING,
+ DRM_PLANE_NO_SCALING,
+ false, false);
+}
+
+static void sharp_memory_plane_atomic_update(struct drm_plane *plane,
+ struct drm_atomic_state *state)
+{
+ struct drm_plane_state *old_state = drm_atomic_get_old_plane_state(state, plane);
+ struct drm_plane_state *plane_state = plane->state;
+ struct drm_format_conv_state fmtcnv_state = DRM_FORMAT_CONV_STATE_INIT;
+ struct sharp_memory_device *smd;
+ struct drm_rect rect;
+
+ smd = container_of(plane, struct sharp_memory_device, plane);
+ if (!smd->crtc.state->active)
+ return;
+
+ if (drm_atomic_helper_damage_merged(old_state, plane_state, &rect))
+ sharp_memory_fb_dirty(plane_state->fb, &rect, &fmtcnv_state);
+
+ drm_format_conv_state_release(&fmtcnv_state);
+}
+
+static const struct drm_plane_helper_funcs sharp_memory_plane_helper_funcs = {
+ .prepare_fb = drm_gem_plane_helper_prepare_fb,
+ .atomic_check = sharp_memory_plane_atomic_check,
+ .atomic_update = sharp_memory_plane_atomic_update,
+};
+
+static bool sharp_memory_format_mod_supported(struct drm_plane *plane,
+ u32 format,
+ u64 modifier)
+{
+ return modifier == DRM_FORMAT_MOD_LINEAR;
+}
+
+static const struct drm_plane_funcs sharp_memory_plane_funcs = {
+ .update_plane = drm_atomic_helper_update_plane,
+ .disable_plane = drm_atomic_helper_disable_plane,
+ .destroy = drm_plane_cleanup,
+ .reset = drm_atomic_helper_plane_reset,
+ .atomic_duplicate_state = drm_atomic_helper_plane_duplicate_state,
+ .atomic_destroy_state = drm_atomic_helper_plane_destroy_state,
+ .format_mod_supported = sharp_memory_format_mod_supported,
+};
+
+static enum drm_mode_status sharp_memory_crtc_mode_valid(struct drm_crtc *crtc,
+ const struct drm_display_mode *mode)
+{
+ struct sharp_memory_device *smd = drm_to_sharp_memory_device(crtc->dev);
+
+ return drm_crtc_helper_mode_valid_fixed(crtc, mode, smd->mode);
+}
+
+static int sharp_memory_crtc_check(struct drm_crtc *crtc,
+ struct drm_atomic_state *state)
+{
+ struct drm_crtc_state *crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
+ int ret;
+
+ if (!crtc_state->enable)
+ goto out;
+
+ ret = drm_atomic_helper_check_crtc_primary_plane(crtc_state);
+ if (ret)
+ return ret;
+
+out:
+ return drm_atomic_add_affected_planes(state, crtc);
+}
+
+static int sharp_memory_sw_vcom_signal_thread(void *data)
+{
+ struct sharp_memory_device *smd = data;
+
+ while (!kthread_should_stop()) {
+ smd->vcom ^= 1; /* Toggle vcom */
+ sharp_memory_maintain_display(smd);
+ msleep(1000);
+ }
+
+ return 0;
+}
+
+static void sharp_memory_crtc_enable(struct drm_crtc *crtc,
+ struct drm_atomic_state *state)
+{
+ struct sharp_memory_device *smd = drm_to_sharp_memory_device(crtc->dev);
+
+ sharp_memory_clear_display(smd);
+
+ if (smd->enable_gpio)
+ gpiod_set_value(smd->enable_gpio, 1);
+}
+
+static void sharp_memory_crtc_disable(struct drm_crtc *crtc,
+ struct drm_atomic_state *state)
+{
+ struct sharp_memory_device *smd = drm_to_sharp_memory_device(crtc->dev);
+
+ sharp_memory_clear_display(smd);
+
+ if (smd->enable_gpio)
+ gpiod_set_value(smd->enable_gpio, 0);
+}
+
+static const struct drm_crtc_helper_funcs sharp_memory_crtc_helper_funcs = {
+ .mode_valid = sharp_memory_crtc_mode_valid,
+ .atomic_check = sharp_memory_crtc_check,
+ .atomic_enable = sharp_memory_crtc_enable,
+ .atomic_disable = sharp_memory_crtc_disable,
+};
+
+static const struct drm_crtc_funcs sharp_memory_crtc_funcs = {
+ .reset = drm_atomic_helper_crtc_reset,
+ .destroy = drm_crtc_cleanup,
+ .set_config = drm_atomic_helper_set_config,
+ .page_flip = drm_atomic_helper_page_flip,
+ .atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
+ .atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
+};
+
+static const struct drm_encoder_funcs sharp_memory_encoder_funcs = {
+ .destroy = drm_encoder_cleanup,
+};
+
+static int sharp_memory_connector_get_modes(struct drm_connector *connector)
+{
+ struct sharp_memory_device *smd = drm_to_sharp_memory_device(connector->dev);
+
+ return drm_connector_helper_get_modes_fixed(connector, smd->mode);
+}
+
+static const struct drm_connector_helper_funcs sharp_memory_connector_hfuncs = {
+ .get_modes = sharp_memory_connector_get_modes,
+};
+
+static const struct drm_connector_funcs sharp_memory_connector_funcs = {
+ .reset = drm_atomic_helper_connector_reset,
+ .fill_modes = drm_helper_probe_single_connector_modes,
+ .destroy = drm_connector_cleanup,
+ .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
+ .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
+
+};
+
+static const struct drm_mode_config_funcs sharp_memory_mode_config_funcs = {
+ .fb_create = drm_gem_fb_create_with_dirty,
+ .atomic_check = drm_atomic_helper_check,
+ .atomic_commit = drm_atomic_helper_commit,
+};
+
+static const struct drm_display_mode sharp_memory_ls010b7dh04_mode = {
+ DRM_SIMPLE_MODE(128, 128, 18, 18),
+};
+
+static const struct drm_display_mode sharp_memory_ls011b7dh03_mode = {
+ DRM_SIMPLE_MODE(160, 68, 25, 10),
+};
+
+static const struct drm_display_mode sharp_memory_ls012b7dd01_mode = {
+ DRM_SIMPLE_MODE(184, 38, 29, 6),
+};
+
+static const struct drm_display_mode sharp_memory_ls013b7dh03_mode = {
+ DRM_SIMPLE_MODE(128, 128, 23, 23),
+};
+
+static const struct drm_display_mode sharp_memory_ls013b7dh05_mode = {
+ DRM_SIMPLE_MODE(144, 168, 20, 24),
+};
+
+static const struct drm_display_mode sharp_memory_ls018b7dh02_mode = {
+ DRM_SIMPLE_MODE(230, 303, 27, 36),
+};
+
+static const struct drm_display_mode sharp_memory_ls027b7dh01_mode = {
+ DRM_SIMPLE_MODE(400, 240, 58, 35),
+};
+
+static const struct drm_display_mode sharp_memory_ls032b7dd02_mode = {
+ DRM_SIMPLE_MODE(336, 536, 42, 68),
+};
+
+static const struct drm_display_mode sharp_memory_ls044q7dh01_mode = {
+ DRM_SIMPLE_MODE(320, 240, 89, 67),
+};
+
+static const struct spi_device_id sharp_memory_ids[] = {
+ {"ls010b7dh04", (kernel_ulong_t)&sharp_memory_ls010b7dh04_mode},
+ {"ls011b7dh03", (kernel_ulong_t)&sharp_memory_ls011b7dh03_mode},
+ {"ls012b7dd01", (kernel_ulong_t)&sharp_memory_ls012b7dd01_mode},
+ {"ls013b7dh03", (kernel_ulong_t)&sharp_memory_ls013b7dh03_mode},
+ {"ls013b7dh05", (kernel_ulong_t)&sharp_memory_ls013b7dh05_mode},
+ {"ls018b7dh02", (kernel_ulong_t)&sharp_memory_ls018b7dh02_mode},
+ {"ls027b7dh01", (kernel_ulong_t)&sharp_memory_ls027b7dh01_mode},
+ {"ls027b7dh01a", (kernel_ulong_t)&sharp_memory_ls027b7dh01_mode},
+ {"ls032b7dd02", (kernel_ulong_t)&sharp_memory_ls032b7dd02_mode},
+ {"ls044q7dh01", (kernel_ulong_t)&sharp_memory_ls044q7dh01_mode},
+ {},
+};
+MODULE_DEVICE_TABLE(spi, sharp_memory_ids);
+
+static const struct of_device_id sharp_memory_of_match[] = {
+ {.compatible = "sharp,ls010b7dh04", &sharp_memory_ls010b7dh04_mode},
+ {.compatible = "sharp,ls011b7dh03", &sharp_memory_ls011b7dh03_mode},
+ {.compatible = "sharp,ls012b7dd01", &sharp_memory_ls012b7dd01_mode},
+ {.compatible = "sharp,ls013b7dh03", &sharp_memory_ls013b7dh03_mode},
+ {.compatible = "sharp,ls013b7dh05", &sharp_memory_ls013b7dh05_mode},
+ {.compatible = "sharp,ls018b7dh02", &sharp_memory_ls018b7dh02_mode},
+ {.compatible = "sharp,ls027b7dh01", &sharp_memory_ls027b7dh01_mode},
+ {.compatible = "sharp,ls027b7dh01a", &sharp_memory_ls027b7dh01_mode},
+ {.compatible = "sharp,ls032b7dd02", &sharp_memory_ls032b7dd02_mode},
+ {.compatible = "sharp,ls044q7dh01", &sharp_memory_ls044q7dh01_mode},
+ {},
+};
+MODULE_DEVICE_TABLE(of, sharp_memory_of_match);
+
+static const u32 sharp_memory_formats[] = {
+ DRM_FORMAT_XRGB8888,
+};
+
+static int sharp_memory_pipe_init(struct drm_device *dev,
+ struct sharp_memory_device *smd,
+ const u32 *formats, unsigned int format_count,
+ const u64 *format_modifiers)
+{
+ int ret;
+ struct drm_encoder *encoder = &smd->encoder;
+ struct drm_plane *plane = &smd->plane;
+ struct drm_crtc *crtc = &smd->crtc;
+ struct drm_connector *connector = &smd->connector;
+
+ drm_plane_helper_add(plane, &sharp_memory_plane_helper_funcs);
+ ret = drm_universal_plane_init(dev, plane, 0,
+ &sharp_memory_plane_funcs,
+ formats, format_count,
+ format_modifiers,
+ DRM_PLANE_TYPE_PRIMARY, NULL);
+ if (ret)
+ return ret;
+
+ drm_crtc_helper_add(crtc, &sharp_memory_crtc_helper_funcs);
+ ret = drm_crtc_init_with_planes(dev, crtc, plane, NULL,
+ &sharp_memory_crtc_funcs, NULL);
+ if (ret)
+ return ret;
+
+ encoder->possible_crtcs = drm_crtc_mask(crtc);
+ ret = drm_encoder_init(dev, encoder, &sharp_memory_encoder_funcs,
+ DRM_MODE_ENCODER_NONE, NULL);
+ if (ret)
+ return ret;
+
+ ret = drm_connector_init(&smd->drm, &smd->connector,
+ &sharp_memory_connector_funcs,
+ DRM_MODE_CONNECTOR_SPI);
+ if (ret)
+ return ret;
+
+ drm_connector_helper_add(&smd->connector,
+ &sharp_memory_connector_hfuncs);
+
+ return drm_connector_attach_encoder(connector, encoder);
+}
+
+static int sharp_memory_init_pwm_vcom_signal(struct sharp_memory_device *smd)
+{
+ struct pwm_state pwm_state;
+ struct device *dev = &smd->spi->dev;
+
+ smd->pwm_vcom_signal = devm_pwm_get(dev, NULL);
+ if (IS_ERR(smd->pwm_vcom_signal))
+ return dev_err_probe(dev, -EINVAL, "Could not get pwm device\n");
+
+ pwm_init_state(smd->pwm_vcom_signal, &pwm_state);
+ pwm_set_relative_duty_cycle(&pwm_state, 1, 10);
+ pwm_state.enabled = true;
+ pwm_apply_might_sleep(smd->pwm_vcom_signal, &pwm_state);
+
+ return 0;
+}
+
+static int sharp_memory_probe(struct spi_device *spi)
+{
+ int ret;
+ struct device *dev;
+ struct sharp_memory_device *smd;
+ struct drm_device *drm;
+ const char *vcom_mode_str;
+
+ dev = &spi->dev;
+
+ ret = spi_setup(spi);
+ if (ret < 0)
+ return dev_err_probe(dev, ret, "Failed to setup spi device\n");
+
+ 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(dev, &sharp_memory_drm_driver,
+ struct sharp_memory_device, drm);
+ if (!smd)
+ return -ENOMEM;
+
+ 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)
+ dev_warn(dev, "Enable gpio not defined\n");
+
+ drm->mode_config.funcs = &sharp_memory_mode_config_funcs;
+ smd->mode = spi_get_device_match_data(spi);
+
+ 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(dev, smd->tx_buffer_size, GFP_KERNEL);
+ if (!smd->tx_buffer)
+ return -ENOMEM;
+
+ mutex_init(&smd->tx_mutex);
+
+ /*
+ * 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
+ *
+ */
+ if (device_property_read_string(dev, "sharp,vcom-mode", &vcom_mode_str))
+ return dev_err_probe(dev, -EINVAL,
+ "Unable to find sharp,vcom-mode node in device tree\n");
+
+ if (!strcmp("software", vcom_mode_str)) {
+ smd->vcom_mode = SHARP_MEMORY_SOFTWARE_VCOM;
+ smd->sw_vcom_signal = kthread_run(sharp_memory_sw_vcom_signal_thread,
+ smd, "sw_vcom_signal");
+
+ } else if (!strcmp("external", vcom_mode_str)) {
+ smd->vcom_mode = SHARP_MEMORY_EXTERNAL_VCOM;
+
+ } else if (!strcmp("pwm", vcom_mode_str)) {
+ smd->vcom_mode = SHARP_MEMORY_PWM_VCOM;
+ ret = sharp_memory_init_pwm_vcom_signal(smd);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "Failed to initialize external COM signal\n");
+ } else {
+ return dev_err_probe(dev, -EINVAL, "Invalid value set for vcom-mode\n");
+ }
+
+ 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,
+ 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;
+}
+
+static void sharp_memory_remove(struct spi_device *spi)
+{
+ struct sharp_memory_device *smd = spi_get_drvdata(spi);
+
+ drm_dev_unplug(&smd->drm);
+ drm_atomic_helper_shutdown(&smd->drm);
+
+ switch (smd->vcom_mode) {
+ case SHARP_MEMORY_SOFTWARE_VCOM:
+ kthread_stop(smd->sw_vcom_signal);
+ break;
+
+ case SHARP_MEMORY_EXTERNAL_VCOM:
+ break;
+
+ case SHARP_MEMORY_PWM_VCOM:
+ pwm_disable(smd->pwm_vcom_signal);
+ break;
+ }
+}
+
+static struct spi_driver sharp_memory_spi_driver = {
+ .driver = {
+ .name = "sharp_memory",
+ .of_match_table = sharp_memory_of_match,
+ },
+ .probe = sharp_memory_probe,
+ .remove = sharp_memory_remove,
+ .id_table = sharp_memory_ids,
+};
+module_spi_driver(sharp_memory_spi_driver);
+
+MODULE_AUTHOR("Alex Lanzano <lanzano.alex@gmail.com>");
+MODULE_DESCRIPTION("SPI Protocol driver for the sharp_memory display");
+MODULE_LICENSE("GPL");
--
2.46.2