--- /dev/null
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * DRM driver for Ilitek ILI9486 panels
+ *
+ * Copyright 2020 Kamlesh Gurudasani <kamlesh.gurudasani@gmail.com>
+ */
+
+#include <linux/backlight.h>
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/module.h>
+#include <linux/property.h>
+#include <linux/spi/spi.h>
+
+#include <video/mipi_display.h>
+
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_drv.h>
+#include <drm/drm_fb_helper.h>
+#include <drm/drm_gem_cma_helper.h>
+#include <drm/drm_gem_framebuffer_helper.h>
+#include <drm/drm_mipi_dbi.h>
+#include <drm/drm_modeset_helper.h>
+
+#define ILI9486_ITFCTR1 0xb0
+#define ILI9486_PWCTRL1 0xc2
+#define ILI9486_VMCTRL1 0xc5
+#define ILI9486_PGAMCTRL 0xe0
+#define ILI9486_NGAMCTRL 0xe1
+#define ILI9486_DGAMCTRL 0xe2
+#define ILI9486_MADCTL_BGR BIT(3)
+#define ILI9486_MADCTL_MV BIT(5)
+#define ILI9486_MADCTL_MX BIT(6)
+#define ILI9486_MADCTL_MY BIT(7)
+
+/*
+ * The PiScreen/waveshare rpi-lcd-35 has a SPI to 16-bit parallel bus converter
+ * in front of the display controller. This means that 8-bit values have to be
+ * transferred as 16-bit.
+ */
+static int waveshare_command(struct mipi_dbi *mipi, u8 *cmd, u8 *par,
+ size_t num)
+{
+ struct spi_device *spi = mipi->spi;
+ void *data = par;
+ u32 speed_hz;
+ int i, ret;
+ u16 *buf;
+
+ buf = kmalloc(32 * sizeof(u16), GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ /*
+ * The displays are Raspberry Pi HATs and connected to the 8-bit only
+ * SPI controller, so 16-bit command and parameters need byte swapping
+ * before being transferred as 8-bit on the big endian SPI bus.
+ * Pixel data bytes have already been swapped before this function is
+ * called.
+ */
+ buf[0] = cpu_to_be16(*cmd);
+ gpiod_set_value_cansleep(mipi->dc, 0);
+ speed_hz = mipi_dbi_spi_cmd_max_speed(spi, 2);
+ ret = mipi_dbi_spi_transfer(spi, speed_hz, 8, buf, 2);
+ if (ret || !num)
+ goto free;
+
+ /* 8-bit configuration data, not 16-bit pixel data */
+ if (num <= 32) {
+ for (i = 0; i < num; i++)
+ buf[i] = cpu_to_be16(par[i]);
+ num *= 2;
+ speed_hz = mipi_dbi_spi_cmd_max_speed(spi, num);
+ data = buf;
+ }
+
+ gpiod_set_value_cansleep(mipi->dc, 1);
+ ret = mipi_dbi_spi_transfer(spi, speed_hz, 8, data, num);
+ free:
+ kfree(buf);
+
+ return ret;
+}
+
+static void waveshare_enable(struct drm_simple_display_pipe *pipe,
+ struct drm_crtc_state *crtc_state,
+ struct drm_plane_state *plane_state)
+{
+ struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(pipe->crtc.dev);
+ struct mipi_dbi *dbi = &dbidev->dbi;
+ u8 addr_mode;
+ int ret, idx;
+
+ if (!drm_dev_enter(pipe->crtc.dev, &idx))
+ return;
+
+ DRM_DEBUG_KMS("\n");
+
+ ret = mipi_dbi_poweron_conditional_reset(dbidev);
+ if (ret < 0)
+ goto out_exit;
+ if (ret == 1)
+ goto out_enable;
+
+ mipi_dbi_command(dbi, ILI9486_ITFCTR1);
+ mipi_dbi_command(dbi, MIPI_DCS_EXIT_SLEEP_MODE);
+ msleep(250);
+
+ mipi_dbi_command(dbi, MIPI_DCS_SET_PIXEL_FORMAT, 0x55);
+
+ mipi_dbi_command(dbi, ILI9486_PWCTRL1, 0x44);
+
+ mipi_dbi_command(dbi, ILI9486_VMCTRL1, 0x00, 0x00, 0x00, 0x00);
+
+ mipi_dbi_command(dbi, ILI9486_PGAMCTRL,
+ 0x0F, 0x1F, 0x1C, 0x0C, 0x0F, 0x08, 0x48, 0x98,
+ 0x37, 0x0A, 0x13, 0x04, 0x11, 0x0D, 0x0);
+ mipi_dbi_command(dbi, ILI9486_NGAMCTRL,
+ 0x0F, 0x32, 0x2E, 0x0B, 0x0D, 0x05, 0x47, 0x75,
+ 0x37, 0x06, 0x10, 0x03, 0x24, 0x20, 0x00);
+ mipi_dbi_command(dbi, ILI9486_DGAMCTRL,
+ 0x0F, 0x32, 0x2E, 0x0B, 0x0D, 0x05, 0x47, 0x75,
+ 0x37, 0x06, 0x10, 0x03, 0x24, 0x20, 0x00);
+
+ mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_ON);
+ msleep(100);
+
+ out_enable:
+ switch (dbidev->rotation) {
+ case 90:
+ addr_mode = ILI9486_MADCTL_MY;
+ break;
+ case 180:
+ addr_mode = ILI9486_MADCTL_MV;
+ break;
+ case 270:
+ addr_mode = ILI9486_MADCTL_MX;
+ break;
+ default:
+ addr_mode = ILI9486_MADCTL_MV | ILI9486_MADCTL_MY |
+ ILI9486_MADCTL_MX;
+ break;
+ }
+ addr_mode |= ILI9486_MADCTL_BGR;
+ mipi_dbi_command(dbi, MIPI_DCS_SET_ADDRESS_MODE, addr_mode);
+ mipi_dbi_enable_flush(dbidev, crtc_state, plane_state);
+ out_exit:
+ drm_dev_exit(idx);
+}
+
+static const struct drm_simple_display_pipe_funcs waveshare_pipe_funcs = {
+ .enable = waveshare_enable,
+ .disable = mipi_dbi_pipe_disable,
+ .update = mipi_dbi_pipe_update,
+ .prepare_fb = drm_gem_fb_simple_display_pipe_prepare_fb,
+};
+
+static const struct drm_display_mode waveshare_mode = {
+ DRM_SIMPLE_MODE(480, 320, 73, 49),
+};
+
+DEFINE_DRM_GEM_CMA_FOPS(ili9486_fops);
+
+static struct drm_driver ili9486_driver = {
+ .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
+ .fops = &ili9486_fops,
+ .release = mipi_dbi_release,
+ DRM_GEM_CMA_VMAP_DRIVER_OPS,
+ .debugfs_init = mipi_dbi_debugfs_init,
+ .name = "ili9486",
+ .desc = "Ilitek ILI9486",
+ .date = "20200118",
+ .major = 1,
+ .minor = 0,
+};
+
+static const struct of_device_id ili9486_of_match[] = {
+ { .compatible = "waveshare,rpi-lcd-35" },
+ { .compatible = "ozzmaker,piscreen" },
+ {},
+};
+MODULE_DEVICE_TABLE(of, ili9486_of_match);
+
+static const struct spi_device_id ili9486_id[] = {
+ { "ili9486", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(spi, ili9486_id);
+
+static int ili9486_probe(struct spi_device *spi)
+{
+ struct device *dev = &spi->dev;
+ struct mipi_dbi_dev *dbidev;
+ struct drm_device *drm;
+ struct mipi_dbi *dbi;
+ struct gpio_desc *dc;
+ u32 rotation = 0;
+ int ret;
+
+ dbidev = kzalloc(sizeof(*dbidev), GFP_KERNEL);
+ if (!dbidev)
+ return -ENOMEM;
+
+ dbi = &dbidev->dbi;
+ drm = &dbidev->drm;
+ ret = devm_drm_dev_init(dev, drm, &ili9486_driver);
+ if (ret) {
+ kfree(dbidev);
+ return ret;
+ }
+
+ drm_mode_config_init(drm);
+
+ dbi->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
+ if (IS_ERR(dbi->reset)) {
+ DRM_DEV_ERROR(dev, "Failed to get gpio 'reset'\n");
+ return PTR_ERR(dbi->reset);
+ }
+
+ dc = devm_gpiod_get(dev, "dc", GPIOD_OUT_LOW);
+ if (IS_ERR(dc)) {
+ DRM_DEV_ERROR(dev, "Failed to get gpio 'dc'\n");
+ return PTR_ERR(dc);
+ }
+
+ dbidev->backlight = devm_of_find_backlight(dev);
+ if (IS_ERR(dbidev->backlight))
+ return PTR_ERR(dbidev->backlight);
+
+ device_property_read_u32(dev, "rotation", &rotation);
+
+ ret = mipi_dbi_spi_init(spi, dbi, dc);
+ if (ret)
+ return ret;
+
+ dbi->command = waveshare_command;
+ dbi->read_commands = NULL;
+
+ ret = mipi_dbi_dev_init(dbidev, &waveshare_pipe_funcs,
+ &waveshare_mode, rotation);
+ if (ret)
+ return ret;
+
+ drm_mode_config_reset(drm);
+
+ ret = drm_dev_register(drm, 0);
+ if (ret)
+ return ret;
+
+ spi_set_drvdata(spi, drm);
+
+ drm_fbdev_generic_setup(drm, 0);
+
+ return 0;
+}
+
+static int ili9486_remove(struct spi_device *spi)
+{
+ struct drm_device *drm = spi_get_drvdata(spi);
+
+ drm_dev_unplug(drm);
+ drm_atomic_helper_shutdown(drm);
+
+ return 0;
+}
+
+static void ili9486_shutdown(struct spi_device *spi)
+{
+ drm_atomic_helper_shutdown(spi_get_drvdata(spi));
+}
+
+static struct spi_driver ili9486_spi_driver = {
+ .driver = {
+ .name = "ili9486",
+ .of_match_table = ili9486_of_match,
+ },
+ .id_table = ili9486_id,
+ .probe = ili9486_probe,
+ .remove = ili9486_remove,
+ .shutdown = ili9486_shutdown,
+};
+module_spi_driver(ili9486_spi_driver);
+
+MODULE_DESCRIPTION("Ilitek ILI9486 DRM driver");
+MODULE_AUTHOR("Kamlesh Gurudasani <kamlesh.gurudasani@gmail.com>");
+MODULE_LICENSE("GPL");
projects / kernel.git / commitdiff