[PATCH v3 2/2] drm/tiny: add display driver for philips pcd8544 display controller
Viktar Simanenka
viteosen at gmail.com
Thu Jul 20 12:40:26 UTC 2023
Add support for monochrome LCD SPI displays (such as Nokia 5110/3310 LCD)
based on PCD8544 LCD display controller.
Signed-off-by: Viktar Simanenka <viteosen at gmail.com>
---
v3:nothing changed from v2
v2:checked and fixed with sparse and smatch
changed param prefixes
v2 link: https://lore.kernel.org/linux-devicetree/20230719154450.620410-2-viteosen@gmail.com/
drivers/gpu/drm/tiny/Kconfig | 11 +
drivers/gpu/drm/tiny/Makefile | 1 +
drivers/gpu/drm/tiny/pcd8544.c | 506 +++++++++++++++++++++++++++++++++
3 files changed, 518 insertions(+)
create mode 100644 drivers/gpu/drm/tiny/pcd8544.c
diff --git a/drivers/gpu/drm/tiny/Kconfig b/drivers/gpu/drm/tiny/Kconfig
index f6889f649bc1..10caa0818253 100644
--- a/drivers/gpu/drm/tiny/Kconfig
+++ b/drivers/gpu/drm/tiny/Kconfig
@@ -172,6 +172,17 @@ config TINYDRM_MI0283QT
DRM driver for the Multi-Inno MI0283QT display panel
If M is selected the module will be called mi0283qt.
+config TINYDRM_PCD8544
+ tristate "DRM support for PCD8544 displays"
+ depends on DRM && SPI
+ select DRM_KMS_HELPER
+ select DRM_GEM_DMA_HELPER
+ select BACKLIGHT_CLASS_DEVICE
+ help
+ DRM driver for PCD8544 (Nokia 5110/3310) 84x48 LCD displays.
+
+ If M is selected the module will be called pcd8544.
+
config TINYDRM_REPAPER
tristate "DRM support for Pervasive Displays RePaper panels (V231)"
depends on DRM && SPI
diff --git a/drivers/gpu/drm/tiny/Makefile b/drivers/gpu/drm/tiny/Makefile
index 76dde89a044b..75bc112a02f9 100644
--- a/drivers/gpu/drm/tiny/Makefile
+++ b/drivers/gpu/drm/tiny/Makefile
@@ -13,6 +13,7 @@ obj-$(CONFIG_TINYDRM_ILI9225) += ili9225.o
obj-$(CONFIG_TINYDRM_ILI9341) += ili9341.o
obj-$(CONFIG_TINYDRM_ILI9486) += ili9486.o
obj-$(CONFIG_TINYDRM_MI0283QT) += mi0283qt.o
+obj-$(CONFIG_TINYDRM_PCD8544) += pcd8544.o
obj-$(CONFIG_TINYDRM_REPAPER) += repaper.o
obj-$(CONFIG_TINYDRM_ST7586) += st7586.o
obj-$(CONFIG_TINYDRM_ST7735R) += st7735r.o
diff --git a/drivers/gpu/drm/tiny/pcd8544.c b/drivers/gpu/drm/tiny/pcd8544.c
new file mode 100644
index 000000000000..73958b302a36
--- /dev/null
+++ b/drivers/gpu/drm/tiny/pcd8544.c
@@ -0,0 +1,506 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * DRM driver for Philips PCD8544 LCD controller/driver.
+ * Compatible with Nokia 5110/3310 84x48 LCD displays.
+ *
+ * Copyright 2023 Viktar Simanenka <viteosen at gmail.com>
+ */
+
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/module.h>
+#include <linux/property.h>
+#include <linux/spi/spi.h>
+
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_damage_helper.h>
+#include <drm/drm_drv.h>
+#include <drm/drm_fb_dma_helper.h>
+#include <drm/drm_fb_helper.h>
+#include <drm/drm_fbdev_generic.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_probe_helper.h>
+#include <drm/drm_rect.h>
+#include <drm/drm_simple_kms_helper.h>
+
+/*
+ * The display is monochrome, every bit in buffer is a pixel.
+ * Display RAM divided into 6 banks along y-axis, each bank 84 bytes along x-axis.
+ * Driver uses horizontal addressing.
+ */
+
+#define PCD8544_FUNCTIONSET 0x20
+#define PCD8544_DISPLAYCONTROL 0x08
+#define PCD8544_SETYADDR 0x40
+#define PCD8544_SETXADDR 0x80
+#define PCD8544_SETBIAS 0x10
+#define PCD8544_SETTEMPCOEF 0x04
+#define PCD8544_SETVOP 0x80
+
+#define PCD8544_EXTENDED_INSTRUCTION 0x01
+#define PCD8544_VERTICAL_ADDRESSING 0x02
+#define PCD8544_DISPLAYNORMAL 0x04
+#define PCD8544_DISPLAYINVERTED 0x05
+
+struct pcd8544_device {
+ struct drm_device drm;
+ struct drm_simple_display_pipe pipe;
+ struct drm_connector connector;
+ struct drm_display_mode mode;
+ struct spi_device *spi;
+
+ u32 width;
+ u32 height;
+ u8 *tx_buf; // Buffer used for transfer
+ size_t tx_buflen;
+
+ struct backlight_device *backlight;
+ struct gpio_desc *reset;
+ struct gpio_desc *dc;
+
+ u32 inverted;
+ u32 temperature_coeff;
+ u32 bias;
+ u32 voltage_op;
+};
+
+MODULE_PARM_DESC(inverted, "Invert display colors: 1 - enable, 0 - disable");
+MODULE_PARM_DESC(voltage_op, "Vop[6:0] LCD voltage operation coefficient: 0-127 (default: 0)");
+MODULE_PARM_DESC(temperature_coeff, "TC[1:0] Temperature compensation coefficient: 0-3 (default: 0)");
+MODULE_PARM_DESC(bias, "BS[2:0] Bias system coefficient: 0-7 (default: 4)");
+
+#define drm_to_dev(__dev) container_of(__dev, struct pcd8544_device, drm)
+
+static int pcd8544_spi_transfer(struct spi_device *spi, const void *buf, size_t len)
+{
+ size_t max_chunk = spi_max_transfer_size(spi);
+ struct spi_transfer tr = {
+ .bits_per_word = 8,
+ .speed_hz = 0,
+ };
+ struct spi_message m;
+ size_t chunk;
+ int ret;
+
+ max_chunk = ALIGN_DOWN(max_chunk, 2);
+
+ spi_message_init_with_transfers(&m, &tr, 1);
+
+ while (len) {
+ chunk = min(len, max_chunk);
+
+ tr.tx_buf = buf;
+ tr.len = chunk;
+ buf += chunk;
+ len -= chunk;
+
+ ret = spi_sync(spi, &m);
+ if (ret)
+ return ret;
+ }
+ return 0;
+}
+
+static int pcd8544_spi_command(struct pcd8544_device *pcd8544_dev, u8 cmd)
+{
+ struct spi_device *spi = pcd8544_dev->spi;
+
+ gpiod_set_value_cansleep(pcd8544_dev->dc, 0);
+
+ return pcd8544_spi_transfer(spi, &cmd, 1);
+}
+
+static int pcd8544_spi_data(struct pcd8544_device *pcd8544_dev,
+ const void *tx_buf, size_t len)
+{
+ struct spi_device *spi = pcd8544_dev->spi;
+
+ gpiod_set_value_cansleep(pcd8544_dev->dc, 1);
+
+ return pcd8544_spi_transfer(spi, tx_buf, len);
+}
+
+static void pcd8544_screen_update(struct pcd8544_device *pcd8544_dev,
+ const u8 *buf, size_t len, u8 addr_x, u8 addr_y)
+{
+ pcd8544_spi_command(pcd8544_dev, PCD8544_SETYADDR | addr_y);
+ pcd8544_spi_command(pcd8544_dev, PCD8544_SETXADDR | addr_x);
+ pcd8544_spi_data(pcd8544_dev, buf, len);
+}
+
+static int pcd8544_fb_xrgb8888_to_mono(u8 *dst, struct drm_framebuffer *fb,
+ struct drm_rect *clip)
+{
+ struct iosys_map fb_map[DRM_FORMAT_MAX_PLANES];
+ struct iosys_map fb_data[DRM_FORMAT_MAX_PLANES];
+ struct iosys_map buf_map;
+ u8 *buf;
+ unsigned int width = drm_rect_width(clip);
+ unsigned int height = drm_rect_height(clip);
+ unsigned int line_length = DIV_ROUND_UP(width, 8);
+ unsigned int bank_max = DIV_ROUND_UP(height, 8);
+ unsigned int x, y, bank;
+ int ret = 0;
+
+ buf = kcalloc(line_length, height, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ buf_map = (struct iosys_map)IOSYS_MAP_INIT_VADDR(buf);
+
+ ret = drm_gem_fb_begin_cpu_access(fb, DMA_FROM_DEVICE);
+ if (ret)
+ goto out_free;
+
+ ret = drm_gem_fb_vmap(fb, fb_map, fb_data);
+ if (ret)
+ goto out_end_cpu_access;
+
+ drm_fb_xrgb8888_to_mono(&buf_map, &line_length, fb_data, fb, clip);
+
+ drm_gem_fb_vunmap(fb, fb_map);
+
+ for (bank = 0; bank < bank_max; bank++) {
+ for (x = 0; x < width; x++) {
+ u8 data = 0;
+
+ for (y = 0; y < 8; y++) {
+ u8 byte = buf[(8 * bank + y) * line_length + x / 8];
+ u8 bit = (byte >> (x % 8)) & 1;
+
+ data |= bit << y;
+ }
+ *dst++ = data;
+ }
+ }
+
+out_end_cpu_access:
+ drm_gem_fb_end_cpu_access(fb, DMA_FROM_DEVICE);
+out_free:
+ kfree(buf);
+
+ return ret;
+}
+
+static void pcd8544_fb_dirty(struct drm_framebuffer *fb, struct drm_rect *rect)
+{
+ struct pcd8544_device *pcd8544_dev = drm_to_dev(fb->dev);
+ int idx, ret = 0;
+
+ if (!drm_dev_enter(fb->dev, &idx))
+ return;
+
+ /* Align rect y to display bank boundaries */
+ rect->y1 = round_down(rect->y1, 8);
+ rect->y2 = min_t(unsigned int, round_up(rect->y2, 8), pcd8544_dev->width);
+
+ ret = pcd8544_fb_xrgb8888_to_mono(pcd8544_dev->tx_buf, fb, rect);
+ if (ret)
+ goto err_msg;
+
+ /* if full update */
+ if (rect->x1 == 0 && rect->x2 == pcd8544_dev->width &&
+ rect->y1 == 0 && rect->y2 == pcd8544_dev->height) {
+ pcd8544_screen_update(pcd8544_dev, pcd8544_dev->tx_buf, pcd8544_dev->tx_buflen, 0, 0);
+ } else {
+ u32 rect_width = drm_rect_width(rect);
+ u32 bank_min = rect->y1 / 8;
+ u32 bank_max = rect->y2 / 8;
+
+ for (u32 bank = bank_min; bank <= bank_max; bank++)
+ pcd8544_screen_update(pcd8544_dev, &pcd8544_dev->tx_buf[rect_width * (bank - bank_min)],
+ rect_width, rect->x1, bank);
+ }
+
+err_msg:
+ if (ret)
+ dev_err_once(fb->dev->dev, "Failed to update display %d\n", ret);
+
+ drm_dev_exit(idx);
+}
+
+static enum drm_mode_status pcd8544_pipe_mode_valid(struct drm_simple_display_pipe *pipe,
+ const struct drm_display_mode *mode)
+{
+ struct drm_crtc *crtc = &pipe->crtc;
+ struct pcd8544_device *pcd8544_dev = drm_to_dev(crtc->dev);
+
+ return drm_crtc_helper_mode_valid_fixed(crtc, mode, &pcd8544_dev->mode);
+}
+
+static void pcd8544_pipe_enable(struct drm_simple_display_pipe *pipe,
+ struct drm_crtc_state *crtc_state,
+ struct drm_plane_state *plane_state)
+{
+ struct pcd8544_device *pcd8544_dev = drm_to_dev(pipe->crtc.dev);
+ struct drm_framebuffer *fb = plane_state->fb;
+ struct drm_rect rect = {
+ .x1 = 0,
+ .x2 = fb->width,
+ .y1 = 0,
+ .y2 = fb->height,
+ };
+ int idx;
+
+ if (!drm_dev_enter(pipe->crtc.dev, &idx))
+ return;
+
+ drm_dbg(pipe->crtc.dev, "\n");
+
+ /* Reset display */
+ gpiod_set_value_cansleep(pcd8544_dev->reset, 0);
+ usleep_range(20, 1000);
+ gpiod_set_value_cansleep(pcd8544_dev->reset, 1);
+ msleep(120);
+
+ /* Init */
+ pcd8544_spi_command(pcd8544_dev, PCD8544_FUNCTIONSET | PCD8544_EXTENDED_INSTRUCTION);
+ pcd8544_spi_command(pcd8544_dev, PCD8544_SETBIAS | (pcd8544_dev->bias & 0x7));
+ pcd8544_spi_command(pcd8544_dev, PCD8544_SETTEMPCOEF | (pcd8544_dev->temperature_coeff & 0x3));
+ pcd8544_spi_command(pcd8544_dev, PCD8544_SETVOP | (pcd8544_dev->voltage_op & 0x7F));
+ pcd8544_spi_command(pcd8544_dev, PCD8544_FUNCTIONSET);
+ if (pcd8544_dev->inverted)
+ pcd8544_spi_command(pcd8544_dev, PCD8544_DISPLAYCONTROL | PCD8544_DISPLAYINVERTED);
+ else
+ pcd8544_spi_command(pcd8544_dev, PCD8544_DISPLAYCONTROL | PCD8544_DISPLAYNORMAL);
+
+ pcd8544_fb_dirty(fb, &rect);
+
+ drm_dev_exit(idx);
+}
+
+static void pcd8544_pipe_disable(struct drm_simple_display_pipe *pipe)
+{
+ struct pcd8544_device *pcd8544_dev = drm_to_dev(pipe->crtc.dev);
+
+ drm_dbg(pipe->crtc.dev, "\n");
+
+ /* Clear screen */
+ memset(pcd8544_dev->tx_buf, 0, pcd8544_dev->tx_buflen);
+ pcd8544_screen_update(pcd8544_dev, pcd8544_dev->tx_buf, pcd8544_dev->tx_buflen, 0, 0);
+
+ if (pcd8544_dev->backlight)
+ backlight_disable(pcd8544_dev->backlight);
+}
+
+static void pcd8544_pipe_update(struct drm_simple_display_pipe *pipe,
+ struct drm_plane_state *old_state)
+{
+ struct drm_plane_state *state = pipe->plane.state;
+ struct drm_rect rect;
+
+ if (!pipe->crtc.state->active)
+ return;
+
+ if (drm_atomic_helper_damage_merged(old_state, state, &rect))
+ pcd8544_fb_dirty(state->fb, &rect);
+}
+
+static const struct drm_simple_display_pipe_funcs pcd8544_pipe_funcs = {
+ .mode_valid = pcd8544_pipe_mode_valid,
+ .enable = pcd8544_pipe_enable,
+ .disable = pcd8544_pipe_disable,
+ .update = pcd8544_pipe_update,
+};
+
+DEFINE_DRM_GEM_DMA_FOPS(pcd8544_fops);
+
+static int pcd8544_connector_get_modes(struct drm_connector *connector)
+{
+ struct pcd8544_device *pcd8544_dev = drm_to_dev(connector->dev);
+
+ return drm_connector_helper_get_modes_fixed(connector, &pcd8544_dev->mode);
+}
+
+static const struct drm_connector_helper_funcs pcd8544_connector_hfuncs = {
+ .get_modes = pcd8544_connector_get_modes,
+};
+
+static const struct drm_connector_funcs pcd8544_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 pcd8544_mode_config_funcs = {
+ .fb_create = drm_gem_fb_create_with_dirty,
+ .atomic_check = drm_atomic_helper_check,
+ .atomic_commit = drm_atomic_helper_commit,
+};
+
+static int __maybe_unused pcd8544_pm_suspend(struct device *dev)
+{
+ return drm_mode_config_helper_suspend(dev_get_drvdata(dev));
+}
+
+static int __maybe_unused pcd8544_pm_resume(struct device *dev)
+{
+ drm_mode_config_helper_resume(dev_get_drvdata(dev));
+
+ return 0;
+}
+
+static const struct dev_pm_ops pcd8544_pm_ops = {
+ SET_SYSTEM_SLEEP_PM_OPS(pcd8544_pm_suspend, pcd8544_pm_resume)
+};
+
+static const struct drm_driver pcd8544_driver = {
+ .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
+ .fops = &pcd8544_fops,
+ DRM_GEM_DMA_DRIVER_OPS_VMAP,
+ .name = "pcd8544",
+ .desc = "Philips PCD8544",
+ .date = "20230701",
+ .major = 1,
+ .minor = 0,
+};
+
+static const uint32_t pcd8544_formats[] = {
+ DRM_FORMAT_XRGB8888,
+};
+
+static struct drm_display_mode pcd8544_mode = {
+ DRM_SIMPLE_MODE(84, 48, 35, 28),
+};
+
+static const struct of_device_id pcd8544_of_match[] = {
+ { .compatible = "nxp,pcd8544" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, pcd8544_of_match);
+
+static const struct spi_device_id pcd8544_id[] = {
+ { "pcd8544", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(spi, pcd8544_id);
+
+static int pcd8544_probe(struct spi_device *spi)
+{
+ struct device *dev = &spi->dev;
+ struct pcd8544_device *pcd8544_dev;
+ struct drm_device *drm;
+ int ret;
+ static const uint64_t modifiers[] = {
+ DRM_FORMAT_MOD_LINEAR,
+ DRM_FORMAT_MOD_INVALID
+ };
+
+ pcd8544_dev = devm_drm_dev_alloc(dev, &pcd8544_driver, struct pcd8544_device, drm);
+ if (IS_ERR(pcd8544_dev))
+ return PTR_ERR(pcd8544_dev);
+
+ pcd8544_dev->spi = spi;
+
+ pcd8544_dev->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
+ if (IS_ERR(pcd8544_dev->reset))
+ return dev_err_probe(dev, PTR_ERR(pcd8544_dev->reset), "Failed to get GPIO 'reset'\n");
+
+ pcd8544_dev->dc = devm_gpiod_get(dev, "dc", GPIOD_OUT_LOW);
+ if (IS_ERR(pcd8544_dev->dc))
+ return dev_err_probe(dev, PTR_ERR(pcd8544_dev->dc), "Failed to get GPIO 'dc'\n");
+
+ pcd8544_dev->backlight = devm_of_find_backlight(dev);
+ if (IS_ERR(pcd8544_dev->backlight))
+ return PTR_ERR(pcd8544_dev->backlight);
+
+ pcd8544_dev->inverted = device_property_read_bool(dev, "nxp,inverted");
+ if (device_property_read_u32(dev, "nxp,temperature-coeff", &pcd8544_dev->temperature_coeff))
+ pcd8544_dev->temperature_coeff = 0;
+ if (device_property_read_u32(dev, "nxp,bias", &pcd8544_dev->bias))
+ pcd8544_dev->bias = 4;
+ if (device_property_read_u32(dev, "nxp,voltage-op", &pcd8544_dev->voltage_op))
+ pcd8544_dev->voltage_op = 0;
+
+ if (!dev->coherent_dma_mask) {
+ ret = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(32));
+ if (ret) {
+ dev_warn(dev, "Failed to set dma mask %d\n", ret);
+ return ret;
+ }
+ }
+
+ drm_mode_copy(&pcd8544_dev->mode, &pcd8544_mode);
+ pcd8544_dev->width = pcd8544_mode.hdisplay;
+ pcd8544_dev->height = pcd8544_mode.vdisplay;
+ pcd8544_dev->tx_buflen = pcd8544_dev->width * DIV_ROUND_UP(pcd8544_dev->height, 8);
+ pcd8544_dev->tx_buf = devm_kzalloc(dev, pcd8544_dev->tx_buflen, GFP_KERNEL);
+ if (!pcd8544_dev->tx_buf)
+ return -ENOMEM;
+
+ drm = &pcd8544_dev->drm;
+ ret = drmm_mode_config_init(drm);
+ if (ret)
+ return ret;
+
+ drm_connector_helper_add(&pcd8544_dev->connector, &pcd8544_connector_hfuncs);
+ ret = drm_connector_init(drm, &pcd8544_dev->connector, &pcd8544_connector_funcs, DRM_MODE_CONNECTOR_SPI);
+ if (ret)
+ return ret;
+
+ drm->mode_config.funcs = &pcd8544_mode_config_funcs;
+ drm->mode_config.min_width = pcd8544_dev->mode.hdisplay;
+ drm->mode_config.max_width = pcd8544_dev->mode.hdisplay;
+ drm->mode_config.min_height = pcd8544_dev->mode.vdisplay;
+ drm->mode_config.max_height = pcd8544_dev->mode.vdisplay;
+
+ ret = drm_simple_display_pipe_init(drm, &pcd8544_dev->pipe, &pcd8544_pipe_funcs,
+ pcd8544_formats, ARRAY_SIZE(pcd8544_formats),
+ modifiers, &pcd8544_dev->connector);
+ if (ret)
+ return ret;
+
+ drm_plane_enable_fb_damage_clips(&pcd8544_dev->pipe.plane);
+
+ spi_set_drvdata(spi, drm);
+
+ drm_mode_config_reset(drm);
+
+ ret = drm_dev_register(drm, 0);
+ if (ret)
+ return ret;
+
+ drm_dbg(drm, "SPI speed: %uMHz\n", spi->max_speed_hz / 1000000);
+
+ drm_fbdev_generic_setup(drm, 0);
+
+ return 0;
+}
+
+static void pcd8544_remove(struct spi_device *spi)
+{
+ struct drm_device *drm = spi_get_drvdata(spi);
+
+ drm_dev_unplug(drm);
+ drm_atomic_helper_shutdown(drm);
+}
+
+static void pcd8544_shutdown(struct spi_device *spi)
+{
+ drm_atomic_helper_shutdown(spi_get_drvdata(spi));
+}
+
+static struct spi_driver pcd8544_spi_driver = {
+ .driver = {
+ .name = "pcd8544",
+ .owner = THIS_MODULE,
+ .of_match_table = pcd8544_of_match,
+ .pm = &pcd8544_pm_ops,
+ },
+ .id_table = pcd8544_id,
+ .probe = pcd8544_probe,
+ .remove = pcd8544_remove,
+ .shutdown = pcd8544_shutdown,
+};
+module_spi_driver(pcd8544_spi_driver);
+
+MODULE_DESCRIPTION("Philips PCD8544 DRM driver");
+MODULE_AUTHOR("Viktar Simanenka <viteosen at gmail.com>");
+MODULE_LICENSE("GPL");
--
2.34.1
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