--- /dev/null
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * LCD-OLinuXino support for panel driver
+ *
+ * Copyright (C) 2018 Olimex Ltd.
+ * Author: Stefan Mavrodiev <stefan@olimex.com>
+ */
+
+#include <linux/backlight.h>
+#include <linux/crc32.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/regulator/consumer.h>
+
+#include <drm/drm_modes.h>
+#include <drm/drm_panel.h>
+#include <drm/drmP.h>
+
+#include <video/videomode.h>
+#include <video/display_timing.h>
+
+#define LCD_OLINUXINO_HEADER_MAGIC 0x4F4CB727
+#define LCD_OLINUXINO_DATA_LEN 256
+
+struct lcd_olinuxino_mode {
+ u32 pixelclock;
+ u32 hactive;
+ u32 hfp;
+ u32 hbp;
+ u32 hpw;
+ u32 vactive;
+ u32 vfp;
+ u32 vbp;
+ u32 vpw;
+ u32 refresh;
+ u32 flags;
+};
+
+struct lcd_olinuxino_info {
+ char name[32];
+ u32 width_mm;
+ u32 height_mm;
+ u32 bpc;
+ u32 bus_format;
+ u32 bus_flag;
+} __attribute__((__packed__));
+
+struct lcd_olinuxino_eeprom {
+ u32 header;
+ u32 id;
+ char revision[4];
+ u32 serial;
+ struct lcd_olinuxino_info info;
+ u32 num_modes;
+ u8 reserved[180];
+ u32 checksum;
+} __attribute__((__packed__));
+
+struct lcd_olinuxino {
+ struct drm_panel panel;
+ struct device *dev;
+ struct i2c_client *client;
+ struct mutex mutex;
+
+ bool prepared;
+ bool enabled;
+
+ struct backlight_device *backlight;
+ struct regulator *supply;
+ struct gpio_desc *enable_gpio;
+
+ struct lcd_olinuxino_eeprom eeprom;
+};
+
+static inline struct lcd_olinuxino *to_lcd_olinuxino(struct drm_panel *panel)
+{
+ return container_of(panel, struct lcd_olinuxino, panel);
+}
+
+static int lcd_olinuxino_disable(struct drm_panel *panel)
+{
+ struct lcd_olinuxino *lcd = to_lcd_olinuxino(panel);
+
+ if (!lcd->enabled)
+ return 0;
+
+ backlight_disable(lcd->backlight);
+
+ lcd->enabled = false;
+
+ return 0;
+}
+
+static int lcd_olinuxino_unprepare(struct drm_panel *panel)
+{
+ struct lcd_olinuxino *lcd = to_lcd_olinuxino(panel);
+
+ if (!lcd->prepared)
+ return 0;
+
+ gpiod_set_value_cansleep(lcd->enable_gpio, 0);
+ regulator_disable(lcd->supply);
+
+ lcd->prepared = false;
+
+ return 0;
+}
+
+static int lcd_olinuxino_prepare(struct drm_panel *panel)
+{
+ struct lcd_olinuxino *lcd = to_lcd_olinuxino(panel);
+ int ret;
+
+ if (lcd->prepared)
+ return 0;
+
+ ret = regulator_enable(lcd->supply);
+ if (ret < 0)
+ return ret;
+
+ gpiod_set_value_cansleep(lcd->enable_gpio, 1);
+ lcd->prepared = true;
+
+ return 0;
+}
+
+static int lcd_olinuxino_enable(struct drm_panel *panel)
+{
+ struct lcd_olinuxino *lcd = to_lcd_olinuxino(panel);
+
+ if (lcd->enabled)
+ return 0;
+
+ backlight_enable(lcd->backlight);
+
+ lcd->enabled = true;
+
+ return 0;
+}
+
+static int lcd_olinuxino_get_modes(struct drm_panel *panel)
+{
+ struct lcd_olinuxino *lcd = to_lcd_olinuxino(panel);
+ struct drm_connector *connector = lcd->panel.connector;
+ struct lcd_olinuxino_info *lcd_info = &lcd->eeprom.info;
+ struct drm_device *drm = lcd->panel.drm;
+ struct lcd_olinuxino_mode *lcd_mode;
+ struct drm_display_mode *mode;
+ u32 i, num = 0;
+
+ for (i = 0; i < lcd->eeprom.num_modes; i++) {
+ lcd_mode = (struct lcd_olinuxino_mode *)
+ &lcd->eeprom.reserved[i * sizeof(*lcd_mode)];
+
+ mode = drm_mode_create(drm);
+ if (!mode) {
+ dev_err(drm->dev, "failed to add mode %ux%u@%u\n",
+ lcd_mode->hactive,
+ lcd_mode->vactive,
+ lcd_mode->refresh);
+ continue;
+ }
+
+ mode->clock = lcd_mode->pixelclock;
+ mode->hdisplay = lcd_mode->hactive;
+ mode->hsync_start = lcd_mode->hactive + lcd_mode->hfp;
+ mode->hsync_end = lcd_mode->hactive + lcd_mode->hfp +
+ lcd_mode->hpw;
+ mode->htotal = lcd_mode->hactive + lcd_mode->hfp +
+ lcd_mode->hpw + lcd_mode->hbp;
+ mode->vdisplay = lcd_mode->vactive;
+ mode->vsync_start = lcd_mode->vactive + lcd_mode->vfp;
+ mode->vsync_end = lcd_mode->vactive + lcd_mode->vfp +
+ lcd_mode->vpw;
+ mode->vtotal = lcd_mode->vactive + lcd_mode->vfp +
+ lcd_mode->vpw + lcd_mode->vbp;
+ mode->vrefresh = lcd_mode->refresh;
+
+ /* Always make the first mode preferred */
+ if (i == 0)
+ mode->type |= DRM_MODE_TYPE_PREFERRED;
+ mode->type |= DRM_MODE_TYPE_DRIVER;
+
+ drm_mode_set_name(mode);
+ drm_mode_probed_add(connector, mode);
+
+ num++;
+ }
+
+ memcpy(connector->display_info.name, lcd_info->name, 32);
+ connector->display_info.width_mm = lcd_info->width_mm;
+ connector->display_info.height_mm = lcd_info->height_mm;
+ connector->display_info.bpc = lcd_info->bpc;
+
+ if (lcd_info->bus_format)
+ drm_display_info_set_bus_formats(&connector->display_info,
+ &lcd_info->bus_format, 1);
+ connector->display_info.bus_flags = lcd_info->bus_flag;
+
+ return num;
+}
+
+static const struct drm_panel_funcs lcd_olinuxino_funcs = {
+ .disable = lcd_olinuxino_disable,
+ .unprepare = lcd_olinuxino_unprepare,
+ .prepare = lcd_olinuxino_prepare,
+ .enable = lcd_olinuxino_enable,
+ .get_modes = lcd_olinuxino_get_modes,
+};
+
+static int lcd_olinuxino_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct device *dev = &client->dev;
+ struct lcd_olinuxino *lcd;
+ u32 checksum, i;
+ int ret = 0;
+
+ if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
+ I2C_FUNC_SMBUS_READ_I2C_BLOCK))
+ return -ENODEV;
+
+ lcd = devm_kzalloc(dev, sizeof(*lcd), GFP_KERNEL);
+ if (!lcd)
+ return -ENOMEM;
+
+ i2c_set_clientdata(client, lcd);
+ lcd->dev = dev;
+ lcd->client = client;
+
+ mutex_init(&lcd->mutex);
+
+ /* Copy data into buffer */
+ for (i = 0; i < LCD_OLINUXINO_DATA_LEN; i += I2C_SMBUS_BLOCK_MAX) {
+ mutex_lock(&lcd->mutex);
+ ret = i2c_smbus_read_i2c_block_data(client,
+ i,
+ I2C_SMBUS_BLOCK_MAX,
+ (u8 *)&lcd->eeprom + i);
+ mutex_unlock(&lcd->mutex);
+ if (ret < 0) {
+ dev_err(dev, "error reading from device at %02x\n", i);
+ return ret;
+ }
+ }
+
+ /* Check configuration checksum */
+ checksum = ~crc32(~0, (u8 *)&lcd->eeprom, 252);
+ if (checksum != lcd->eeprom.checksum) {
+ dev_err(dev, "configuration checksum does not match!\n");
+ return -EINVAL;
+ }
+
+ /* Check magic header */
+ if (lcd->eeprom.header != LCD_OLINUXINO_HEADER_MAGIC) {
+ dev_err(dev, "magic header does not match\n");
+ return -EINVAL;
+ }
+
+ dev_info(dev, "Detected %s, Rev. %s, Serial: %08x\n",
+ lcd->eeprom.info.name,
+ lcd->eeprom.revision,
+ lcd->eeprom.serial);
+
+ /*
+ * The eeprom can hold up to 4 modes.
+ * If the stored value is bigger, overwrite it.
+ */
+ if (lcd->eeprom.num_modes > 4) {
+ dev_warn(dev, "invalid number of modes, falling back to 4\n");
+ lcd->eeprom.num_modes = 4;
+ }
+
+ lcd->enabled = false;
+ lcd->prepared = false;
+
+ lcd->supply = devm_regulator_get(dev, "power");
+ if (IS_ERR(lcd->supply))
+ return PTR_ERR(lcd->supply);
+
+ lcd->enable_gpio = devm_gpiod_get(dev, "enable", GPIOD_OUT_LOW);
+ if (IS_ERR(lcd->enable_gpio))
+ return PTR_ERR(lcd->enable_gpio);
+
+ lcd->backlight = devm_of_find_backlight(dev);
+ if (IS_ERR(lcd->backlight))
+ return PTR_ERR(lcd->backlight);
+
+ drm_panel_init(&lcd->panel);
+ lcd->panel.dev = dev;
+ lcd->panel.funcs = &lcd_olinuxino_funcs;
+
+ return drm_panel_add(&lcd->panel);
+}
+
+static int lcd_olinuxino_remove(struct i2c_client *client)
+{
+ struct lcd_olinuxino *panel = i2c_get_clientdata(client);
+
+ drm_panel_remove(&panel->panel);
+
+ lcd_olinuxino_disable(&panel->panel);
+ lcd_olinuxino_unprepare(&panel->panel);
+
+ return 0;
+}
+
+static const struct of_device_id lcd_olinuxino_of_ids[] = {
+ { .compatible = "olimex,lcd-olinuxino" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, lcd_olinuxino_of_ids);
+
+static struct i2c_driver lcd_olinuxino_driver = {
+ .driver = {
+ .name = "lcd_olinuxino",
+ .of_match_table = lcd_olinuxino_of_ids,
+ },
+ .probe = lcd_olinuxino_probe,
+ .remove = lcd_olinuxino_remove,
+};
+
+module_i2c_driver(lcd_olinuxino_driver);
+
+MODULE_AUTHOR("Stefan Mavrodiev <stefan@olimex.com>");
+MODULE_DESCRIPTION("LCD-OLinuXino driver");
+MODULE_LICENSE("GPL");
projects / linux.git / commitdiff