[PATCH v2 3/4] video: add MIPI DBI framebuffer helpers
Philipp Zabel
p.zabel at pengutronix.de
Thu Mar 30 05:46:42 PDT 2023
Port helper functions for the panel-mipi-dbi driver from the Linux
kernel.
Signed-off-by: Philipp Zabel <p.zabel at pengutronix.de>
---
v2:
- Remove superfluous empty line
- Fix mipi_dbi_enable_flush() comment
- Remove unnecessary regulator checks
- Avoid memcpy to tx_buf if byte swapping can be avoided
- Allocate screen_base and tx_buf using dma_alloc(info->screen_size)
- Align mipi_dbi_fb_dirty() a bit more with the original Linux version
---
drivers/video/mipi_dbi.c | 226 +++++++++++++++++++++++++++++++++++++++
include/video/mipi_dbi.h | 63 +++++++++++
2 files changed, 289 insertions(+)
diff --git a/drivers/video/mipi_dbi.c b/drivers/video/mipi_dbi.c
index 50d2fc4b29b9..61b0fbcc49c6 100644
--- a/drivers/video/mipi_dbi.c
+++ b/drivers/video/mipi_dbi.c
@@ -8,11 +8,13 @@
#define pr_fmt(fmt) "mipi-dbi: " fmt
#include <common.h>
+#include <dma.h>
#include <linux/kernel.h>
#include <linux/sizes.h>
#include <gpiod.h>
#include <regulator.h>
#include <spi/spi.h>
+#include <video/backlight.h>
#include <video/mipi_dbi.h>
#include <video/vpl.h>
@@ -196,6 +198,168 @@ int mipi_dbi_command_stackbuf(struct mipi_dbi *dbi, u8 cmd, const u8 *data,
}
EXPORT_SYMBOL(mipi_dbi_command_stackbuf);
+/**
+ * mipi_dbi_buf_copy_swap - Copy a framebuffer swapping MSB/LSB of 16-bit values
+ * @dst: The destination buffer
+ * @info: The source framebuffer info
+ */
+static void mipi_dbi_buf_copy_swap(u16 *dst, struct fb_info *info)
+{
+ u16 *src = (u16 *)info->screen_base;
+ size_t len = info->xres * info->yres;
+ int i;
+
+ for (i = 0; i < len; i++) {
+ *dst++ = *src << 8 | *src >> 8;
+ src++;
+ }
+}
+
+static void mipi_dbi_set_window_address(struct mipi_dbi_dev *dbidev,
+ unsigned int xs, unsigned int xe,
+ unsigned int ys, unsigned int ye)
+{
+ struct mipi_dbi *dbi = &dbidev->dbi;
+
+ xs += dbidev->mode.left_margin;
+ xe += dbidev->mode.left_margin;
+ ys += dbidev->mode.upper_margin;
+ ye += dbidev->mode.upper_margin;
+
+ mipi_dbi_command(dbi, MIPI_DCS_SET_COLUMN_ADDRESS, (xs >> 8) & 0xff,
+ xs & 0xff, (xe >> 8) & 0xff, xe & 0xff);
+ mipi_dbi_command(dbi, MIPI_DCS_SET_PAGE_ADDRESS, (ys >> 8) & 0xff,
+ ys & 0xff, (ye >> 8) & 0xff, ye & 0xff);
+}
+
+static void mipi_dbi_fb_dirty(struct mipi_dbi_dev *dbidev, struct fb_info *info)
+{
+ struct mipi_dbi *dbi = &dbidev->dbi;
+ unsigned int height = info->yres;
+ unsigned int width = info->xres;
+ bool swap = dbi->swap_bytes;
+ int ret;
+ void *tr;
+
+ if (swap) {
+ tr = dbidev->tx_buf;
+ mipi_dbi_buf_copy_swap(tr, info);
+ } else {
+ tr = info->screen_base;
+ }
+
+ mipi_dbi_set_window_address(dbidev, 0, width - 1, 0, height - 1);
+
+ ret = mipi_dbi_command_buf(dbi, MIPI_DCS_WRITE_MEMORY_START, tr,
+ width * height * 2);
+ if (ret)
+ pr_err_once("Failed to update display %d\n", ret);
+}
+
+/**
+ * mipi_dbi_enable_flush - MIPI DBI enable helper
+ * @dbidev: MIPI DBI device structure
+ * @info: Framebuffer info
+ *
+ * Flushes the whole framebuffer and enables the backlight. Drivers can use this
+ * in their &fb_ops->fb_enable callback.
+ */
+void mipi_dbi_enable_flush(struct mipi_dbi_dev *dbidev,
+ struct fb_info *info)
+{
+ mipi_dbi_fb_dirty(dbidev, info);
+
+ if (dbidev->backlight)
+ backlight_set_brightness_default(dbidev->backlight);
+}
+EXPORT_SYMBOL(mipi_dbi_enable_flush);
+
+static void mipi_dbi_blank(struct mipi_dbi_dev *dbidev)
+{
+ u16 height = dbidev->mode.xres;
+ u16 width = dbidev->mode.yres;
+ struct mipi_dbi *dbi = &dbidev->dbi;
+ size_t len = width * height * 2;
+
+ memset(dbidev->tx_buf, 0, len);
+
+ mipi_dbi_set_window_address(dbidev, 0, width - 1, 0, height - 1);
+ mipi_dbi_command_buf(dbi, MIPI_DCS_WRITE_MEMORY_START, dbidev->tx_buf, len);
+}
+
+/**
+ * mipi_dbi_fb_disable - MIPI DBI framebuffer disable helper
+ * @info: Framebuffer info
+ *
+ * This function disables backlight if present, if not the display memory is
+ * blanked. The regulator is disabled if in use. Drivers can use this as their
+ * &fb_ops->fb_disable callback.
+ */
+void mipi_dbi_fb_disable(struct fb_info *info)
+{
+ struct mipi_dbi_dev *dbidev = container_of(info, struct mipi_dbi_dev, info);
+
+ if (dbidev->backlight)
+ backlight_set_brightness(dbidev->backlight, 0);
+ else
+ mipi_dbi_blank(dbidev);
+
+ regulator_disable(dbidev->regulator);
+ regulator_disable(dbidev->io_regulator);
+}
+EXPORT_SYMBOL(mipi_dbi_fb_disable);
+
+void mipi_dbi_fb_flush(struct fb_info *info)
+{
+ struct mipi_dbi_dev *dbidev = container_of(info, struct mipi_dbi_dev, info);
+
+ mipi_dbi_fb_dirty(dbidev, info);
+}
+EXPORT_SYMBOL(mipi_dbi_fb_flush);
+
+/**
+ * mipi_dbi_dev_init - MIPI DBI device initialization
+ * @dbidev: MIPI DBI device structure to initialize
+ * @ops: Framebuffer operations
+ * @mode: Display mode
+ *
+ * This function sets up a &fb_info with one fixed &fb_videomode.
+ * Additionally &mipi_dbi.tx_buf is allocated.
+ *
+ * Supported format: RGB565.
+ *
+ * Returns:
+ * Zero on success, negative error code on failure.
+ */
+int mipi_dbi_dev_init(struct mipi_dbi_dev *dbidev, struct fb_ops *ops,
+ struct fb_videomode *mode)
+{
+ struct fb_info *info = &dbidev->info;
+
+ info->mode = mode;
+ info->fbops = ops;
+ info->dev.parent = dbidev->dev;
+
+ info->xres = mode->xres;
+ info->yres = mode->yres;
+ info->bits_per_pixel = 16;
+ info->line_length = info->xres * 2;
+ info->screen_size = info->line_length * info->yres;
+ info->screen_base = dma_alloc(info->screen_size);
+ memset(info->screen_base, 0, info->screen_size);
+
+ info->red.length = 5;
+ info->red.offset = 11;
+ info->green.length = 6;
+ info->green.offset = 5;
+ info->blue.length = 5;
+ info->blue.offset = 0;
+
+ dbidev->tx_buf = dma_alloc(info->screen_size);
+
+ return 0;
+}
+
/**
* mipi_dbi_hw_reset - Hardware reset of controller
* @dbi: MIPI DBI structure
@@ -246,6 +410,68 @@ bool mipi_dbi_display_is_on(struct mipi_dbi *dbi)
}
EXPORT_SYMBOL(mipi_dbi_display_is_on);
+static int mipi_dbi_poweron_reset_conditional(struct mipi_dbi_dev *dbidev, bool cond)
+{
+ struct device *dev = dbidev->dev;
+ struct mipi_dbi *dbi = &dbidev->dbi;
+ int ret;
+
+ ret = regulator_enable(dbidev->regulator);
+ if (ret) {
+ dev_err(dev, "Failed to enable regulator (%d)\n", ret);
+ return ret;
+ }
+
+ ret = regulator_enable(dbidev->io_regulator);
+ if (ret) {
+ dev_err(dev, "Failed to enable I/O regulator (%d)\n", ret);
+ regulator_disable(dbidev->regulator);
+ return ret;
+ }
+
+ if (cond && mipi_dbi_display_is_on(dbi))
+ return 1;
+
+ mipi_dbi_hw_reset(dbi);
+ ret = mipi_dbi_command(dbi, MIPI_DCS_SOFT_RESET);
+ if (ret) {
+ dev_err(dev, "Failed to send reset command (%d)\n", ret);
+ regulator_disable(dbidev->io_regulator);
+ regulator_disable(dbidev->regulator);
+ return ret;
+ }
+
+ /*
+ * If we did a hw reset, we know the controller is in Sleep mode and
+ * per MIPI DSC spec should wait 5ms after soft reset. If we didn't,
+ * we assume worst case and wait 120ms.
+ */
+ if (dbi->reset)
+ mdelay(5);
+ else
+ mdelay(120);
+
+ return 0;
+}
+
+/**
+ * mipi_dbi_poweron_conditional_reset - MIPI DBI poweron and conditional reset
+ * @dbidev: MIPI DBI device structure
+ *
+ * This function enables the regulator if used and if the display is off, it
+ * does a hardware and software reset. If mipi_dbi_display_is_on() determines
+ * that the display is on, no reset is performed.
+ *
+ * Returns:
+ * Zero if the controller was reset, 1 if the display was already on, or a
+ * negative error code.
+ */
+int mipi_dbi_poweron_conditional_reset(struct mipi_dbi_dev *dbidev)
+{
+ return mipi_dbi_poweron_reset_conditional(dbidev, true);
+}
+EXPORT_SYMBOL(mipi_dbi_poweron_conditional_reset);
+
#if IS_ENABLED(CONFIG_SPI)
/**
diff --git a/include/video/mipi_dbi.h b/include/video/mipi_dbi.h
index 54526006935f..917f7ddd597f 100644
--- a/include/video/mipi_dbi.h
+++ b/include/video/mipi_dbi.h
@@ -11,6 +11,7 @@
#include <linux/types.h>
#include <spi/spi.h>
#include <driver.h>
+#include <fb.h>
struct regulator;
struct fb_videomode;
@@ -55,6 +56,61 @@ struct mipi_dbi {
struct list_head list;
};
+/**
+ * struct mipi_dbi_dev - MIPI DBI device
+ */
+struct mipi_dbi_dev {
+ /**
+ * @dev: Device
+ */
+ struct device *dev;
+
+ /**
+ * @info: Framebuffer info
+ */
+ struct fb_info info;
+
+ /**
+ * @mode: Fixed display mode
+ */
+ struct fb_videomode mode;
+
+ /**
+ * @tx_buf: Buffer used for transfer (copy clip rect area)
+ */
+ u8 *tx_buf;
+
+ /**
+ * @backlight_node: backlight device node (optional)
+ */
+ struct device_node *backlight_node;
+
+ /**
+ * @backlight: backlight device (optional)
+ */
+ struct backlight_device *backlight;
+
+ /**
+ * @regulator: power regulator (Vdd) (optional)
+ */
+ struct regulator *regulator;
+
+ /**
+ * @io_regulator: I/O power regulator (Vddi) (optional)
+ */
+ struct regulator *io_regulator;
+
+ /**
+ * @dbi: MIPI DBI interface
+ */
+ struct mipi_dbi dbi;
+
+ /**
+ * @driver_private: Driver private data.
+ */
+ void *driver_private;
+};
+
static inline const char *mipi_dbi_name(struct mipi_dbi *dbi)
{
return dev_name(&dbi->spi->dev);
@@ -62,8 +118,15 @@ static inline const char *mipi_dbi_name(struct mipi_dbi *dbi)
int mipi_dbi_spi_init(struct spi_device *spi, struct mipi_dbi *dbi,
int dc);
+int mipi_dbi_dev_init(struct mipi_dbi_dev *dbidev,
+ struct fb_ops *ops, struct fb_videomode *mode);
+void mipi_dbi_fb_flush(struct fb_info *info);
+void mipi_dbi_enable_flush(struct mipi_dbi_dev *dbidev,
+ struct fb_info *info);
+void mipi_dbi_fb_disable(struct fb_info *info);
void mipi_dbi_hw_reset(struct mipi_dbi *dbi);
bool mipi_dbi_display_is_on(struct mipi_dbi *dbi);
+int mipi_dbi_poweron_conditional_reset(struct mipi_dbi_dev *dbidev);
u32 mipi_dbi_spi_cmd_max_speed(struct spi_device *spi, size_t len);
int mipi_dbi_spi_transfer(struct spi_device *spi, u32 speed_hz,
--
2.39.2
More information about the barebox
mailing list