diff options
author | Stefan Mavrodiev <stefan@olimex.com> | 2018-07-12 11:21:53 +0300 |
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committer | Thierry Reding <treding@nvidia.com> | 2018-09-27 14:27:24 +0200 |
commit | 17fd7a9d324fd3af613ddd76f0439481acaad23d (patch) | |
tree | a5f4e9e64ae6b8897ad1896d05fa516219fc9f65 /drivers/gpu/drm/panel/panel-olimex-lcd-olinuxino.c | |
parent | 6cbe7cd15f953a8bb49cab9b85077e1ee4e0e999 (diff) | |
download | linux-17fd7a9d324fd3af613ddd76f0439481acaad23d.tar.bz2 |
drm/panel: Add support for Olimex LCD-OLinuXino panel
This patch adds Olimex Ltd. LCD-OLinuXino bridge panel driver. The panel
is used with different LCDs (currently from 480x272 to 1280x800). A
small EEPROM chip is used for identification, which holds some factory
data and timing requirements.
Signed-off-by: Stefan Mavrodiev <stefan@olimex.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1531383729-13932-1-git-send-email-stefan@olimex.com
Diffstat (limited to 'drivers/gpu/drm/panel/panel-olimex-lcd-olinuxino.c')
-rw-r--r-- | drivers/gpu/drm/panel/panel-olimex-lcd-olinuxino.c | 330 |
1 files changed, 330 insertions, 0 deletions
diff --git a/drivers/gpu/drm/panel/panel-olimex-lcd-olinuxino.c b/drivers/gpu/drm/panel/panel-olimex-lcd-olinuxino.c new file mode 100644 index 000000000000..5e8d4523e9ed --- /dev/null +++ b/drivers/gpu/drm/panel/panel-olimex-lcd-olinuxino.c @@ -0,0 +1,330 @@ +// 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"); |