[RFC PATCH] drm: add Atmel LCDC display controller support
Sam Ravnborg
sam at ravnborg.org
Fri Jul 26 20:44:13 UTC 2019
This is the current state of the driver for the at91sam* LCDC IP.
Notice that it needs some other companion drivers and I posted this
code-drop only to support the request for help on the BGR versus RGB
issue.
That said - any review feedback will be appreciated!
Sam
>From c4c2274313dbb23f38626920834819735f70d899 Mon Sep 17 00:00:00 2001
From: Sam Ravnborg <sam at ravnborg.org>
Date: Thu, 27 Dec 2018 02:23:31 +0100
Subject: [PATCH 22/22] drm: add Atmel LCDC display controller support
This is a DRM based driver for the Atmel LCDC IP.
There exist today a framebuffer based driver and
this is a re-implmentation of the same on top of DRM.
The rewrite was based on the original fbdev driver
but the driver has also seen inspiration from
the atmel-hlcdc_dc driver and others.
The driver is not a full replacement:
- STN displays are not supported
STN displays are not considered relevant for
current kernels, and there is no plan to add STN support
The atmel-lcdc driver is divided into a few files:
atmel_lcdc.h - definitions shared by the driver implmentation
../linux/atmel-lcdc.h - definitions shared with the pwm subdriver
atmel_lcdc_drv.c - all the driver details such as DT support etc.
atmel_lcdc_pipe.c - the display pipeline, including the outputs
v3:
- reworked most of the driver after feedback and more testing
Signed-off-by: Sam Ravnborg <sam at ravnborg.org>
Cc: Nicolas Ferre <nicolas.ferre at atmel.com>
Cc: Boris Brezillon <boris.brezillon at free-electrons.com>
Cc: Alexandre Belloni <alexandre.belloni at bootlin.com>
---
drivers/gpu/drm/Makefile | 1 +
drivers/gpu/drm/atmel/Kconfig | 12 +
drivers/gpu/drm/atmel/Makefile | 3 +
drivers/gpu/drm/atmel/atmel_lcdc.h | 81 +++
drivers/gpu/drm/atmel/atmel_lcdc_drv.c | 408 ++++++++++++++
drivers/gpu/drm/atmel/atmel_lcdc_pipe.c | 675 ++++++++++++++++++++++++
6 files changed, 1180 insertions(+)
create mode 100644 drivers/gpu/drm/atmel/atmel_lcdc.h
create mode 100644 drivers/gpu/drm/atmel/atmel_lcdc_drv.c
create mode 100644 drivers/gpu/drm/atmel/atmel_lcdc_pipe.c
diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index d7f5328918ab..386fc6166de1 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -87,6 +87,7 @@ obj-$(CONFIG_DRM_UDL) += udl/
obj-$(CONFIG_DRM_AST) += ast/
obj-$(CONFIG_DRM_ARMADA) += armada/
obj-$(CONFIG_DRM_ATMEL_HLCDC) += atmel/
+obj-$(CONFIG_DRM_ATMEL_LCDC) += atmel/
obj-y += rcar-du/
obj-$(CONFIG_DRM_SHMOBILE) +=shmobile/
obj-y += omapdrm/
diff --git a/drivers/gpu/drm/atmel/Kconfig b/drivers/gpu/drm/atmel/Kconfig
index 5f67f001553b..1405ae2802a3 100644
--- a/drivers/gpu/drm/atmel/Kconfig
+++ b/drivers/gpu/drm/atmel/Kconfig
@@ -9,3 +9,15 @@ config DRM_ATMEL_HLCDC
help
Choose this option if you have an ATMEL SoC with an HLCDC display
controller (i.e. at91sam9n12, at91sam9x5 family or sama5d3 family).
+
+config DRM_ATMEL_LCDC
+ tristate "DRM Support for ATMEL LCDC Display Controller"
+ depends on DRM && OF && COMMON_CLK && MFD_ATMEL_LCDC
+ depends on ARM || COMPILE_TEST
+ select DRM_GEM_CMA_HELPER
+ select DRM_KMS_HELPER
+ select DRM_KMS_CMA_HELPER
+ select DRM_PANEL
+ help
+ Choose this option if you have an ATMEL SoC with an LCDC display
+ controller (found on many SoC's in the at91sam9 family).
diff --git a/drivers/gpu/drm/atmel/Makefile b/drivers/gpu/drm/atmel/Makefile
index 49dc89f36b73..9d95543f39a3 100644
--- a/drivers/gpu/drm/atmel/Makefile
+++ b/drivers/gpu/drm/atmel/Makefile
@@ -5,3 +5,6 @@ atmel-hlcdc-dc-y := atmel_hlcdc_crtc.o \
atmel_hlcdc_plane.o
obj-$(CONFIG_DRM_ATMEL_HLCDC) += atmel-hlcdc-dc.o
+
+atmel-lcdc-y := atmel_lcdc_drv.o atmel_lcdc_pipe.o
+obj-$(CONFIG_DRM_ATMEL_LCDC) += atmel-lcdc.o
diff --git a/drivers/gpu/drm/atmel/atmel_lcdc.h b/drivers/gpu/drm/atmel/atmel_lcdc.h
new file mode 100644
index 000000000000..e1b3290c3c81
--- /dev/null
+++ b/drivers/gpu/drm/atmel/atmel_lcdc.h
@@ -0,0 +1,81 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2018 Sam Ravnborg
+ *
+ * Author: Sam Ravnborg <sam at ravnborg.org>
+ */
+
+#ifndef __DRM_ATMEL_LCDC_H
+#define __DRM_ATMEL_LCDC_H
+
+#include <linux/workqueue.h>
+
+#include <drm/drm_connector.h>
+#include <drm/drm_simple_kms_helper.h>
+
+#include <linux/mfd/atmel-lcdc.h>
+
+struct clk;
+struct regmap;
+struct regulator;
+
+#define ATMEL_LCDC_DMA_BURST_LEN 8 /* words */
+
+/*
+ * struct atmel_lcdc_desc - CPU specific configuration properties
+ */
+struct atmel_lcdc_desc {
+ /* Default is 1, maybe we need to change this later */
+ int guard_time;
+
+ /* 512 or 2018 */
+ int fifo_size;
+
+ /* Maximum resolution */
+ int max_width;
+ int max_height;
+
+ /* false if "Pixel_clock = system_clock / (CLKVAL + 1) x 2" */
+ /* true if "Pixel_clock = system_clock / (CLKVAL + 1)" */
+ bool have_alt_pixclock;
+};
+
+/*
+ * Private data for the lcdc driver
+ */
+struct lcdc {
+ struct drm_device drm;
+ struct device *dev;
+
+ const struct atmel_lcdc_desc *desc;
+
+ struct atmel_mfd_lcdc *mfd;
+
+ bool wiring_reversed; /* Select between BGR or RGB */
+
+ struct drm_simple_display_pipe pipe;
+ struct work_struct reset_lcdc_work;
+
+ struct drm_panel *panel;
+ struct drm_connector *connector;
+
+ struct mutex enable_lock;
+ bool enabled;
+
+ /* Saved state during suspend */
+ struct {
+ u32 imr;
+ /* true if suspended */
+ bool state;
+ } suspend;
+};
+
+/* atmel_lcdc_pipe.c */
+int atmel_lcdc_vblank_init(struct lcdc *lcdc);
+void atmel_lcdc_vblank(struct lcdc *ldcd);
+
+void atmel_lcdc_start(struct lcdc *lcdc);
+void atmel_lcdc_stop(struct lcdc *lcdc);
+int atmel_lcdc_modeset_init(struct lcdc *lcdc);
+
+#endif /* __DRM_ATMEL_LCDC_H */
diff --git a/drivers/gpu/drm/atmel/atmel_lcdc_drv.c b/drivers/gpu/drm/atmel/atmel_lcdc_drv.c
new file mode 100644
index 000000000000..2c94761ea648
--- /dev/null
+++ b/drivers/gpu/drm/atmel/atmel_lcdc_drv.c
@@ -0,0 +1,408 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2018 Sam Ravnborg
+ *
+ * The driver is based on atmel_lcdfb which is:
+ * Copyright (C) 2007 Atmel Corporation
+ *
+ */
+
+/**
+ * DOC: Atmel LCD Controller Display Controller.
+ *
+ * The Atmel LCD Controller supports in the following configuration:
+ * - TFT only, 24 bits/pixel
+ * - Resolution up to 2048x2048
+ * - Single plane, crtc, one fixed output
+ *
+ * Features not (yet) ported from atmel_lcdfb:
+ * - set color / palette handling
+ */
+
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_crtc_helper.h>
+#include <drm/drm_drv.h>
+#include <drm/drm_fb_helper.h>
+#include <drm/drm_gem_cma_helper.h>
+#include <drm/drm_irq.h>
+#include <drm/drm_print.h>
+#include <drm/drm_probe_helper.h>
+
+#include "atmel_lcdc.h"
+
+/* Configuration of individual CPU's */
+static const struct atmel_lcdc_desc lcdc_at91sam9261 = {
+ .guard_time = 1,
+ .fifo_size = 512,
+ .max_width = 2048,
+ .max_height = 2048,
+ .have_alt_pixclock = false,
+};
+
+static const struct atmel_lcdc_desc lcdc_at91sam9263 = {
+ .guard_time = 1,
+ .fifo_size = 2048,
+ .max_width = 2048,
+ .max_height = 2048,
+ .have_alt_pixclock = false,
+};
+
+static const struct atmel_lcdc_desc lcdc_at91sam9g10 = {
+ .guard_time = 1,
+ .fifo_size = 512,
+ .max_width = 2048,
+ .max_height = 2048,
+ .have_alt_pixclock = false,
+};
+
+static const struct atmel_lcdc_desc lcdc_at91sam9g45 = {
+ .guard_time = 1,
+ .fifo_size = 512,
+ .max_width = 2048,
+ .max_height = 2048,
+ .have_alt_pixclock = true,
+};
+
+static const struct atmel_lcdc_desc lcdc_at91sam9g46 = {
+ .guard_time = 1,
+ .fifo_size = 512,
+ .max_width = 2048,
+ .max_height = 2048,
+ .have_alt_pixclock = true,
+};
+
+static const struct atmel_lcdc_desc lcdc_at91sam9m10 = {
+ .guard_time = 1,
+ .fifo_size = 512,
+ .max_width = 2048,
+ .max_height = 2048,
+ .have_alt_pixclock = true,
+};
+
+static const struct atmel_lcdc_desc lcdc_at91sam9m11 = {
+ .guard_time = 1,
+ .fifo_size = 512,
+ .max_width = 2048,
+ .max_height = 2048,
+ .have_alt_pixclock = true,
+};
+
+static const struct atmel_lcdc_desc lcdc_at91sam9rl = {
+ .guard_time = 1,
+ .fifo_size = 512,
+ .max_width = 2048,
+ .max_height = 2048,
+ .have_alt_pixclock = false,
+};
+
+static const struct of_device_id lcdc_of_match[] = {
+ { .compatible = "atmel,at91sam9261-lcdc", .data = &lcdc_at91sam9261 },
+ { .compatible = "atmel,at91sam9263-lcdc", .data = &lcdc_at91sam9263 },
+ { .compatible = "atmel,at91sam9g10-lcdc", .data = &lcdc_at91sam9g10 },
+ { .compatible = "atmel,at91sam9g45-lcdc", .data = &lcdc_at91sam9g45 },
+ { .compatible = "atmel,at91sam9g45es-lcdc", .data = &lcdc_at91sam9g45 },
+ { .compatible = "atmel,at91sam9g46-lcdc", .data = &lcdc_at91sam9g46 },
+ { .compatible = "atmel,at91sam9m10-lcdc", .data = &lcdc_at91sam9m10 },
+ { .compatible = "atmel,at91sam9m11-lcdc", .data = &lcdc_at91sam9m11 },
+ { .compatible = "atmel,at91sam9rl-lcdc", .data = &lcdc_at91sam9rl },
+ { /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, lcdc_of_match);
+
+
+/* scheduled worker to reset LCD */
+static void reset_lcdc_work(struct work_struct *work)
+{
+ struct lcdc *lcdc;
+
+ lcdc = container_of(work, struct lcdc, reset_lcdc_work);
+
+ mutex_lock(&lcdc->enable_lock);
+
+ /* Check that we are enabled and not suspended */
+ if (lcdc->enabled && !lcdc->suspend.state) {
+ atmel_lcdc_stop(lcdc);
+ atmel_lcdc_start(lcdc);
+ }
+ mutex_unlock(&lcdc->enable_lock);
+}
+
+static irqreturn_t lcdc_irq_handler(int irq, void *arg)
+{
+ struct drm_device *drm;
+ unsigned int status;
+ struct lcdc *lcdc;
+ unsigned int imr;
+ unsigned int isr;
+
+ drm = arg;
+ lcdc = drm->dev_private;
+
+ regmap_read(lcdc->mfd->regmap, ATMEL_LCDC_IMR, &imr);
+ regmap_read(lcdc->mfd->regmap, ATMEL_LCDC_ISR, &isr);
+ status = imr & isr;
+ if (!status)
+ return IRQ_NONE;
+
+ if (status & ATMEL_LCDC_LSTLNI)
+ atmel_lcdc_vblank(lcdc);
+
+ if (status & ATMEL_LCDC_UFLWI) {
+ DRM_DEV_INFO(lcdc->dev, "FIFO underflow %#x\n", status);
+ /* reset DMA and FIFO to avoid screen shifting */
+ schedule_work(&lcdc->reset_lcdc_work);
+ }
+
+ if (status & ATMEL_LCDC_OWRI)
+ DRM_DEV_INFO(lcdc->dev, "FIFO overwrite interrupt\n");
+
+ if (status & ATMEL_LCDC_MERI)
+ DRM_DEV_INFO(lcdc->dev, "DMA memory error\n");
+
+ /* Clear all reported (from ISR) interrupts */
+ regmap_write(lcdc->mfd->regmap, ATMEL_LCDC_ICR, isr);
+
+ return IRQ_HANDLED;
+}
+
+static int lcdc_irq_postinstall(struct drm_device *dev)
+{
+ struct lcdc *lcdc;
+ unsigned int ier;
+
+ lcdc = dev->dev_private;
+
+ ier = 0;
+ /* FIFO underflow interrupt enable */
+ ier |= ATMEL_LCDC_UFLWI;
+ /* FIFO overwrite interrupt enable */
+ ier |= ATMEL_LCDC_OWRI;
+ /* DMA memory error interrupt enable */
+ ier |= ATMEL_LCDC_MERI;
+ regmap_write(lcdc->mfd->regmap, ATMEL_LCDC_IER, ier);
+
+ return 0;
+}
+
+static void lcdc_irq_uninstall(struct drm_device *dev)
+{
+ struct lcdc *lcdc;
+ unsigned int isr;
+
+ lcdc = dev->dev_private;
+
+ /* disable all interrupts */
+ regmap_write(lcdc->mfd->regmap, ATMEL_LCDC_IDR, ~0);
+ regmap_write(lcdc->mfd->regmap, ATMEL_LCDC_ICR, ~0);
+
+ /* Clear any pending interrupts */
+ regmap_read(lcdc->mfd->regmap, ATMEL_LCDC_ISR, &isr);
+}
+
+static void lcdc_release(struct drm_device *drm)
+{
+ struct lcdc *lcdc;
+
+ lcdc = drm->dev_private;
+
+ flush_work(&lcdc->reset_lcdc_work);
+ drm_kms_helper_poll_fini(drm);
+
+ drm_mode_config_cleanup(drm);
+
+ pm_runtime_get_sync(drm->dev);
+ drm_irq_uninstall(drm);
+ pm_runtime_put_sync(drm->dev);
+ cancel_work_sync(&lcdc->reset_lcdc_work);
+ pm_runtime_disable(drm->dev);
+
+ drm_dev_fini(drm);
+ kfree(lcdc);
+}
+
+DEFINE_DRM_GEM_CMA_FOPS(lcdc_drm_fops);
+
+static struct drm_driver lcdc_drm_driver = {
+ .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
+ .name = ATMEL_LCDC_DRM_DRV_NAME,
+ .desc = "Atmel LCD Display Controller DRM",
+ .date = "20180808",
+ .major = 1,
+ .minor = 0,
+ .patchlevel = 0,
+
+ .irq_handler = lcdc_irq_handler,
+ .irq_preinstall = lcdc_irq_uninstall,
+ .irq_postinstall = lcdc_irq_postinstall,
+ .irq_uninstall = lcdc_irq_uninstall,
+
+ .fops = &lcdc_drm_fops,
+ .release = lcdc_release,
+
+ DRM_GEM_CMA_VMAP_DRIVER_OPS,
+};
+
+static int lcdc_probe(struct platform_device *pdev)
+{
+ const struct of_device_id *match;
+ struct atmel_mfd_lcdc *mfd;
+ struct drm_device *drm;
+ struct device *dev;
+ struct lcdc *lcdc;
+ int ret;
+
+ dev = pdev->dev.parent;
+ mfd = dev_get_drvdata(dev);
+ /* the MFD device driver prepares clocks etc. */
+ if (!mfd)
+ return -EPROBE_DEFER;
+
+
+ lcdc = kzalloc(sizeof(*lcdc), GFP_KERNEL);
+ if (!lcdc)
+ return -ENOMEM;
+
+ drm = &lcdc->drm;
+ ret = devm_drm_dev_init(dev, drm, &lcdc_drm_driver);
+ if (ret) {
+ kfree(lcdc);
+ return ret;
+ }
+
+ match = of_match_node(lcdc_of_match, dev->of_node);
+ if (!match || !match->data) {
+ DRM_DEV_ERROR(dev, "failed to find compatible match\n");
+ return -EINVAL;
+ }
+
+ lcdc->desc = match->data;
+
+ drm->dev_private = lcdc;
+ lcdc->dev = dev;
+ lcdc->mfd = mfd;
+ platform_set_drvdata(pdev, drm);
+
+ mutex_init(&lcdc->enable_lock);
+
+ /* reset of lcdc might sleep and require a preemptible task context */
+ INIT_WORK(&lcdc->reset_lcdc_work, reset_lcdc_work);
+
+ pm_runtime_enable(dev);
+
+ ret = atmel_lcdc_vblank_init(lcdc);
+ if (ret)
+ goto err_pm_runtime_disable;
+
+ ret = atmel_lcdc_modeset_init(lcdc);
+ if (ret)
+ goto err_pm_runtime_disable;
+
+ pm_runtime_get_sync(dev);
+
+ ret = drm_irq_install(drm, mfd->irq);
+ pm_runtime_put_sync(dev);
+ if (ret < 0) {
+ DRM_DEV_ERROR(dev, "failed to install IRQ: %d\n", ret);
+ goto err_pm_runtime_disable;
+ }
+
+ drm_kms_helper_poll_init(drm);
+
+ ret = drm_dev_register(drm, 0);
+ if (ret) {
+ DRM_DEV_ERROR(dev, "failed to register drm: %d\n", ret);
+ goto err_pm_runtime_disable;
+ }
+
+ ret = drm_fbdev_generic_setup(drm, 24);
+ if (ret < 0)
+ DRM_DEV_ERROR(dev, "failed to initialize fbdev: %d\n", ret);
+
+ return 0;
+
+err_pm_runtime_disable:
+ cancel_work_sync(&lcdc->reset_lcdc_work);
+ pm_runtime_disable(dev);
+
+ return ret;
+}
+
+static int lcdc_remove(struct platform_device *pdev)
+{
+ struct drm_device *drm;
+
+ drm = platform_get_drvdata(pdev);
+ drm_dev_unregister(drm);
+ drm_atomic_helper_shutdown(drm);
+
+ return 0;
+}
+
+static void lcdc_shutdown(struct platform_device *pdev)
+{
+ drm_atomic_helper_shutdown(platform_get_drvdata(pdev));
+}
+
+static int __maybe_unused lcdc_drm_suspend(struct device *dev)
+{
+ struct drm_device *drm;
+ struct lcdc *lcdc;
+ int ret;
+
+ drm = dev_get_drvdata(dev);
+ lcdc = drm->dev_private;
+
+ ret = drm_mode_config_helper_suspend(drm);
+ if (ret < 0)
+ return ret;
+
+ lcdc->suspend.state = true;
+
+ /* Disable interrupts */
+ regmap_read(lcdc->mfd->regmap, ATMEL_LCDC_IMR, &lcdc->suspend.imr);
+ regmap_write(lcdc->mfd->regmap, ATMEL_LCDC_IDR, lcdc->suspend.imr);
+
+ return 0;
+}
+
+static int __maybe_unused lcdc_drm_resume(struct device *dev)
+{
+ struct drm_device *drm;
+ struct lcdc *lcdc;
+
+ drm = dev_get_drvdata(dev);
+ lcdc = drm->dev_private;
+
+ /* Enable interrupts */
+ regmap_write(lcdc->mfd->regmap, ATMEL_LCDC_IER, lcdc->suspend.imr);
+
+ lcdc->suspend.state = false;
+ return drm_mode_config_helper_resume(drm);
+}
+
+static SIMPLE_DEV_PM_OPS(lcdc_pm_ops,
+ lcdc_drm_suspend, lcdc_drm_resume);
+
+static struct platform_driver lcdc_driver = {
+ .driver = {
+ .name = ATMEL_LCDC_DRM_DRV_NAME,
+ .of_match_table = lcdc_of_match,
+ .pm = &lcdc_pm_ops,
+ },
+ .probe = lcdc_probe,
+ .remove = lcdc_remove,
+ .shutdown = lcdc_shutdown,
+};
+
+module_platform_driver(lcdc_driver);
+
+MODULE_AUTHOR("Sam Ravnborg <sam at ravnborg.org>");
+MODULE_DESCRIPTION("Atmel LCDC Display Controller DRM Driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:atmel-lcdc");
diff --git a/drivers/gpu/drm/atmel/atmel_lcdc_pipe.c b/drivers/gpu/drm/atmel/atmel_lcdc_pipe.c
new file mode 100644
index 000000000000..c40175cd1e1f
--- /dev/null
+++ b/drivers/gpu/drm/atmel/atmel_lcdc_pipe.c
@@ -0,0 +1,675 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2018 Sam Ravnborg
+ *
+ */
+
+#include <linux/regulator/consumer.h>
+#include <linux/pm_runtime.h>
+
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_device.h>
+#include <drm/drm_fb_cma_helper.h>
+#include <drm/drm_fourcc.h>
+#include <drm/drm_gem_framebuffer_helper.h>
+#include <drm/drm_of.h>
+#include <drm/drm_panel.h>
+#include <drm/drm_print.h>
+#include <drm/drm_vblank.h>
+
+#include "atmel_lcdc.h"
+
+/**
+ * DOC: Display pipe for Atmel LCDC
+ *
+ * The LCDC display pipe utilize the drm_simple_kms_helper infrastructure
+ * to provide the necessary DRM functionality.
+ *
+ * The LCDC IP core is always used in setups with only a single
+ * output with direct connection to a panel.
+ */
+
+/*
+ * Atmel LCD controller 24 bit formats.
+ * Formats for reversed wiring included.
+ */
+static const u32 bgr_formats[] = {
+ DRM_FORMAT_XBGR8888,
+ DRM_FORMAT_BGR888,
+ DRM_FORMAT_BGR565,
+};
+
+static const u32 rgb_formats[] = {
+ DRM_FORMAT_XRGB8888,
+ DRM_FORMAT_RGB888,
+ DRM_FORMAT_RGB565,
+};
+
+static const u32* get_formats(bool reversed, size_t *nformats)
+{
+ if (reversed) {
+ /* B and R are swapped in HW */
+ *nformats = ARRAY_SIZE(rgb_formats);
+ return rgb_formats;
+ } else {
+ /* Normal wiring, use BGR formats */
+ *nformats = ARRAY_SIZE(bgr_formats);
+ return bgr_formats;
+ }
+}
+
+static void set_lcdcon2(struct lcdc *lcdc,
+ const struct drm_format_info *format)
+{
+ struct drm_format_name_buf format_buf;
+ struct drm_display_mode *dmode;
+ unsigned int lcdcon2;
+ u32 bus_flags;
+
+ dmode = &lcdc->pipe.crtc.state->adjusted_mode;
+
+ /* Control register 2 */
+ /* Only TFT supported (Controller supports STN too) */
+ lcdcon2 = ATMEL_LCDC_DISTYPE_TFT;
+
+ /* scan mode */
+ if (dmode->flags & DRM_MODE_FLAG_DBLSCAN)
+ lcdcon2 |= ATMEL_LCDC_SCANMOD_DUAL;
+ else
+ lcdcon2 |= ATMEL_LCDC_SCANMOD_SINGLE;
+
+ /* Interface width 4 bits (STN only) */
+ lcdcon2 |= ATMEL_LCDC_IFWIDTH_4;
+
+ switch (format->format) {
+ case DRM_FORMAT_XBGR8888:
+ case DRM_FORMAT_XRGB8888:
+ /* 32 bit layout */
+ lcdcon2 |= ATMEL_LCDC_PIXELSIZE_24;
+ break;
+ case DRM_FORMAT_BGR888:
+ case DRM_FORMAT_RGB888:
+ /* 24 bit layout */
+ lcdcon2 |= ATMEL_LCDC_PIXELSIZE_24_PACKED;
+ break;
+ case DRM_FORMAT_BGR565:
+ case DRM_FORMAT_RGB565:
+ /* 16 bit layout */
+ lcdcon2 |= ATMEL_LCDC_PIXELSIZE_16;
+ break;
+ default:
+ lcdcon2 |= ATMEL_LCDC_PIXELSIZE_24;
+ DRM_DEV_INFO(lcdc->dev, "Unsupported format %s\n",
+ drm_get_format_name(format->format, &format_buf));
+ }
+
+ /* LCDD Polarity normal */
+ lcdcon2 |= ATMEL_LCDC_INVVD_NORMAL;
+
+ /* vsync polarity - TODO: Check ! again */
+ if (!(dmode->flags & DRM_MODE_FLAG_PVSYNC))
+ lcdcon2 |= ATMEL_LCDC_INVFRAME_INVERTED;
+ else
+ lcdcon2 |= ATMEL_LCDC_INVFRAME_NORMAL;
+
+ /* hsync polarity - TODO: Check ! again*/
+ if (!(dmode->flags & DRM_MODE_FLAG_PHSYNC))
+ lcdcon2 |= ATMEL_LCDC_INVLINE_INVERTED;
+ else
+ lcdcon2 |= ATMEL_LCDC_INVLINE_NORMAL;
+
+ bus_flags = lcdc->connector->display_info.bus_flags;
+
+ /* dot clock (pix clock) polarity */
+ if (bus_flags & DRM_BUS_FLAG_PIXDATA_NEGEDGE)
+ lcdcon2 |= ATMEL_LCDC_INVCLK_INVERTED;
+ else
+ lcdcon2 |= ATMEL_LCDC_INVCLK_NORMAL;
+
+ /* Date Enable polarity */
+ if (bus_flags & DRM_BUS_FLAG_DE_LOW)
+ lcdcon2 |= ATMEL_LCDC_INVDVAL_INVERTED;
+ else
+ lcdcon2 |= ATMEL_LCDC_INVDVAL_NORMAL;
+
+ /* Clock is always active */
+ lcdcon2 |= ATMEL_LCDC_CLKMOD_ALWAYSACTIVE;
+
+ /* Memory layout */
+ if (format->format & DRM_FORMAT_BIG_ENDIAN)
+ lcdcon2 |= ATMEL_LCDC_MEMOR_BIG;
+ else
+ lcdcon2 |= ATMEL_LCDC_MEMOR_LITTLE;
+
+ regmap_write(lcdc->mfd->regmap, ATMEL_LCDC_LCDCON2, lcdcon2);
+}
+
+/* Check that the configuation is supported */
+static int lcdc_pipe_check(struct drm_simple_display_pipe *pipe,
+ struct drm_plane_state *pstate,
+ struct drm_crtc_state *cstate)
+{
+ const struct drm_display_mode *dmode;
+ struct drm_framebuffer *fb;
+ struct lcdc *lcdc;
+ long clk_rate;
+
+ lcdc = pipe->crtc.dev->dev_private;
+ dmode = &cstate->mode;
+ fb = pstate->fb;
+
+ if (!fb)
+ return 0;
+
+ /* Check if we can support the requested clock rate */
+ clk_rate = dmode->clock * 1000;
+ if (clk_rate > clk_get_rate(lcdc->mfd->lcdc_clk))
+ return -EINVAL;
+
+ /* Only one plane supported */
+ if (fb->format->num_planes != 1)
+ return -EINVAL;
+
+ return 0;
+}
+
+/*
+ * DMA config. Set frame size and burst length
+ * Frame_size equals size of visible area * bits / 32
+ * (size in 32 bit words)
+ */
+static void lcdc_pipe_enable_dma(struct lcdc *lcdc)
+{
+ const struct drm_format_info *format_info;
+ struct drm_plane_state *plane_state;
+ unsigned int width, height;
+ unsigned int frame_size;
+ unsigned int dmafrmcfg;
+
+ plane_state = lcdc->pipe.plane.state;
+ format_info = drm_format_info(plane_state->fb->format->format);
+ width = plane_state->crtc->state->adjusted_mode.hdisplay;
+ height = plane_state->crtc->state->adjusted_mode.vdisplay;
+
+ frame_size = width * height * format_info->depth;
+ dmafrmcfg = frame_size / 32;
+
+ dmafrmcfg |= (ATMEL_LCDC_DMA_BURST_LEN - 1) << ATMEL_LCDC_BLENGTH_OFFSET;
+
+ regmap_write(lcdc->mfd->regmap, ATMEL_LCDC_DMAFRMCFG, dmafrmcfg);
+}
+
+static void set_vertical_timing(struct lcdc *lcdc,
+ struct drm_display_mode *dmode)
+{
+ unsigned int tim1;
+ unsigned int vfp;
+ unsigned int vbp;
+ unsigned int vpw;
+ unsigned int vhdly;
+
+ /* VFP: Vertical Front Porch */
+ vfp = dmode->vsync_start - dmode->vdisplay;
+
+ /* VBP: Vertical Back Porch */
+ vbp = dmode->vtotal - dmode->vsync_end;
+
+ /* VPW: Vertical Synchronization pulse width */
+ vpw = dmode->vsync_end - dmode->vsync_start - 1;
+
+ /* VHDLY: Vertical to horizontal delay */
+ vhdly = 0;
+
+ tim1 = vfp << ATMEL_LCDC_VFP_OFFSET |
+ vbp << ATMEL_LCDC_VBP_OFFSET |
+ vpw << ATMEL_LCDC_VPW_OFFSET |
+ vhdly << ATMEL_LCDC_VHDLY_OFFSET;
+
+ DRM_DEV_DEBUG(lcdc->dev, " TIM1 = %08x\n", tim1);
+ regmap_write(lcdc->mfd->regmap, ATMEL_LCDC_TIM1, tim1);
+}
+
+static void set_horizontal_timing(struct lcdc *lcdc,
+ struct drm_display_mode *dmode)
+{
+ unsigned int tim2;
+ unsigned int hbp;
+ unsigned int hpw;
+ unsigned int hfp;
+
+ /* HBP: Horizontal Back Porch */
+ hbp = dmode->htotal - dmode->hsync_end - 1;
+
+ /* HPW: Horizontal synchronization pulse width */
+ hpw = dmode->hsync_end - dmode->hsync_start - 1;
+
+ /* HFP: Horizontal Front Porch */
+ hfp = dmode->hsync_start - dmode->hdisplay - 2;
+
+ tim2 = hbp << ATMEL_LCDC_HBP_OFFSET |
+ hpw << ATMEL_LCDC_HPW_OFFSET |
+ hfp << ATMEL_LCDC_HFP_OFFSET;
+
+ DRM_DEV_DEBUG(lcdc->dev, " TIM2 = %08x\n", tim2);
+ regmap_write(lcdc->mfd->regmap, ATMEL_LCDC_TIM2, tim2);
+}
+
+static void lcdc_pipe_enable_timing(struct lcdc *lcdc)
+{
+ struct drm_display_mode *dmode;
+ unsigned int value;
+
+ dmode = &lcdc->pipe.crtc.state->adjusted_mode;
+
+ /* Vertical & horizontal timing */
+ set_vertical_timing(lcdc, dmode);
+ set_horizontal_timing(lcdc, dmode);
+
+ /* Display size */
+ value = (dmode->crtc_hdisplay - 1) << ATMEL_LCDC_HOZVAL_OFFSET;
+ value |= dmode->crtc_vdisplay - 1;
+ DRM_DEV_DEBUG(lcdc->dev, " LCDFRMCFG = %08x\n", value);
+ regmap_write(lcdc->mfd->regmap, ATMEL_LCDC_LCDFRMCFG, value);
+
+ /* FIFO Threshold: Use formula from data sheet */
+ value = lcdc->desc->fifo_size - (2 * ATMEL_LCDC_DMA_BURST_LEN + 3);
+ DRM_DEV_DEBUG(lcdc->dev, " FIFO = %08x\n", value);
+ regmap_write(lcdc->mfd->regmap, ATMEL_LCDC_FIFO, value);
+
+ /*
+ * Toggle LCD_MODE every frame
+ * Note: register not documented, this is from atmel_lcdfb
+ */
+ regmap_write(lcdc->mfd->regmap, ATMEL_LCDC_MVAL, 0);
+}
+
+static void lcdc_pipe_enable_ctrl(struct lcdc *lcdc)
+{
+ const struct drm_format_info *format;
+ struct drm_display_mode *dmode;
+ unsigned long clk_value_khz;
+ unsigned int pix_factor;
+ unsigned int lcdcon1;
+
+ format = lcdc->pipe.crtc.primary->state->fb->format;
+ dmode = &lcdc->pipe.crtc.state->adjusted_mode;
+
+ /* LCDC Control register 1 */
+ /* Set pixel clock */
+ if (lcdc->desc->have_alt_pixclock)
+ pix_factor = 1;
+ else
+ pix_factor = 2;
+
+ clk_value_khz = clk_get_rate(lcdc->mfd->lcdc_clk) / 1000;
+ lcdcon1 = DIV_ROUND_UP(clk_value_khz, dmode->clock);
+
+ if (lcdcon1 < pix_factor) {
+ DRM_DEV_INFO(lcdc->dev, "Bypassing pixel clock divider\n");
+ regmap_write(lcdc->mfd->regmap,
+ ATMEL_LCDC_LCDCON1, ATMEL_LCDC_BYPASS);
+ } else {
+
+ lcdcon1 = (lcdcon1 / pix_factor) - 1;
+ DRM_DEV_DEBUG(lcdc->dev, "CLKVAL = 0x%08x\n", lcdcon1);
+ regmap_write(lcdc->mfd->regmap, ATMEL_LCDC_LCDCON1,
+ lcdcon1 << ATMEL_LCDC_CLKVAL_OFFSET);
+ dmode->clock = clk_value_khz / (pix_factor * (lcdcon1 + 1));
+ DRM_DEV_DEBUG(lcdc->dev, "updated pixclk: %u KHz\n",
+ dmode->clock);
+ }
+
+ /* LCDC Control register 2 */
+ set_lcdcon2(lcdc, format);
+}
+
+static void lcdc_pipe_enable(struct drm_simple_display_pipe *pipe,
+ struct drm_crtc_state *cstate,
+ struct drm_plane_state *plane_state)
+{
+ struct drm_device *drm;
+ struct drm_crtc *crtc;
+ struct lcdc *lcdc;
+
+ crtc = &pipe->crtc;
+ drm = crtc->dev;
+ lcdc = drm->dev_private;
+
+ mutex_lock(&lcdc->enable_lock);
+ pm_runtime_get_sync(drm->dev);
+ pm_runtime_forbid(drm->dev);
+
+ lcdc_pipe_enable_timing(lcdc);
+ lcdc_pipe_enable_dma(lcdc);
+ lcdc_pipe_enable_ctrl(lcdc);
+ atmel_lcdc_start(lcdc);
+ drm_crtc_vblank_on(&lcdc->pipe.crtc);
+
+ pm_runtime_put_sync(drm->dev);
+
+ lcdc->enabled = true;
+ mutex_unlock(&lcdc->enable_lock);
+}
+
+static void lcdc_pipe_disable(struct drm_simple_display_pipe *pipe)
+{
+ struct drm_device *drm;
+ struct drm_crtc *crtc;
+ struct lcdc *lcdc;
+
+ crtc = &pipe->crtc;
+ drm = crtc->dev;
+ lcdc = drm->dev_private;
+
+ mutex_lock(&lcdc->enable_lock);
+ pm_runtime_get_sync(drm->dev);
+
+ drm_crtc_vblank_off(crtc);
+ atmel_lcdc_stop(lcdc);
+
+ pm_runtime_allow(drm->dev);
+ pm_runtime_put_sync(drm->dev);
+
+ lcdc->enabled = false;
+ mutex_unlock(&lcdc->enable_lock);
+}
+
+
+static void lcdc_pipe_update_format(struct lcdc *lcdc,
+ struct drm_simple_display_pipe *pipe)
+{
+ struct drm_plane_state *plane_state;
+ struct drm_framebuffer *fb;
+
+ plane_state = pipe->plane.state;
+ fb = plane_state->fb;
+
+ if (fb)
+ set_lcdcon2(lcdc, fb->format);
+}
+
+/* Update DMA addr */
+static void lcdc_pipe_update_dma(struct lcdc *lcdc,
+ struct drm_simple_display_pipe *pipe)
+{
+ struct drm_plane_state *plane_state;
+ struct drm_framebuffer *fb;
+ dma_addr_t dma_addr;
+
+ plane_state = pipe->plane.state;
+ fb = plane_state->fb;
+
+ if (fb) {
+ dma_addr = drm_fb_cma_get_gem_addr(fb, pipe->plane.state, 0);
+
+ /* Set frame buffer DMA base address */
+ regmap_write(lcdc->mfd->regmap, ATMEL_LCDC_DMABADDR1, dma_addr);
+ }
+}
+
+static void lcdc_pipe_update_event(struct drm_simple_display_pipe *pipe)
+{
+ struct drm_pending_vblank_event *event;
+ struct drm_crtc *crtc;
+
+ crtc = &pipe->crtc;
+ if (!crtc)
+ return;
+
+ spin_lock_irq(&crtc->dev->event_lock);
+ event = crtc->state->event;
+ if (event) {
+ crtc->state->event = NULL;
+
+ if (drm_crtc_vblank_get(crtc) == 0)
+ drm_crtc_arm_vblank_event(crtc, event);
+ else
+ drm_crtc_send_vblank_event(crtc, event);
+ }
+ spin_unlock_irq(&crtc->dev->event_lock);
+}
+
+static void lcdc_pipe_update(struct drm_simple_display_pipe *pipe,
+ struct drm_plane_state *old_pstate)
+{
+ struct lcdc *lcdc;
+
+ lcdc = pipe->crtc.dev->dev_private;
+
+ /* Format management */
+ lcdc_pipe_update_format(lcdc, pipe);
+
+ /* DMA engine... */
+ lcdc_pipe_update_dma(lcdc, pipe);
+
+ /* vblank event handling */
+ lcdc_pipe_update_event(pipe);
+}
+
+static int lcdc_pipe_enable_vblank(struct drm_simple_display_pipe *pipe)
+{
+ struct drm_crtc *crtc;
+ struct lcdc *lcdc;
+
+ crtc = &pipe->crtc;
+ lcdc = crtc->dev->dev_private;
+
+ /* Last line interrupt enable */
+ regmap_write(lcdc->mfd->regmap, ATMEL_LCDC_IER, ATMEL_LCDC_LSTLNI);
+
+ return 0;
+}
+
+static void lcdc_pipe_disable_vblank(struct drm_simple_display_pipe *pipe)
+{
+ struct drm_crtc *crtc;
+ struct lcdc *lcdc;
+
+ crtc = &pipe->crtc;
+ lcdc = crtc->dev->dev_private;
+
+ /* Last line interrupt disable */
+ regmap_write(lcdc->mfd->regmap, ATMEL_LCDC_IDR, ATMEL_LCDC_LSTLNI);
+}
+
+const struct drm_simple_display_pipe_funcs lcdc_display_funcs = {
+ .check = lcdc_pipe_check,
+ .enable = lcdc_pipe_enable,
+ .disable = lcdc_pipe_disable,
+ .update = lcdc_pipe_update,
+ .prepare_fb = drm_gem_fb_simple_display_pipe_prepare_fb,
+ .enable_vblank = lcdc_pipe_enable_vblank,
+ .disable_vblank = lcdc_pipe_disable_vblank,
+};
+
+static int lcdc_get_of_wiring(struct lcdc *lcdc,
+ const struct device_node *ep)
+{
+ const char *str;
+ int ret;
+
+ // HACK
+ lcdc->wiring_reversed = true;
+
+ ret = of_property_read_string(ep, "wiring", &str);
+ if (ret)
+ return ret;
+
+ if (strcmp(str, "red-green-reversed") == 0) {
+ lcdc->wiring_reversed = true;
+ } else if (strcmp(str, "straight") == 0) {
+ /* Use default format */
+ } else {
+ DRM_DEV_ERROR(lcdc->dev, "unknown \"wiring\" property: %s\n",
+ str);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int lcdc_display_init(struct lcdc *lcdc)
+{
+ const u32 *formats;
+ size_t nformats;
+ int ret;
+
+ formats = get_formats(lcdc->wiring_reversed, &nformats);
+
+ ret = drm_simple_display_pipe_init(&lcdc->drm, &lcdc->pipe,
+ &lcdc_display_funcs,
+ formats, nformats,
+ NULL, NULL);
+ if (ret < 0)
+ DRM_DEV_ERROR(lcdc->dev, "failed to init display pipe: %d\n",
+ ret);
+
+ return ret;
+}
+
+static int lcdc_attach_panel(struct lcdc *lcdc)
+{
+ struct drm_bridge *bridge;
+ struct drm_panel *panel;
+ struct device_node *np;
+ struct device *dev;
+ int ret;
+
+ dev = lcdc->dev;
+ np = dev->of_node;
+ ret = drm_of_find_panel_or_bridge(np, 0, 0, &panel, NULL);
+ if (ret < 0)
+ return ret;
+
+ if (!panel) {
+ DRM_DEV_ERROR(dev, "no panel found\n");
+ return -ENODEV;
+ }
+
+ lcdc->panel = panel;
+ bridge = devm_drm_panel_bridge_add(dev, panel, DRM_MODE_CONNECTOR_DPI);
+ ret = PTR_ERR_OR_ZERO(bridge);
+ if (ret < 0) {
+ DRM_DEV_ERROR(dev, "failed to add bridge: %d\n", ret);
+ return ret;
+ }
+
+ ret = lcdc_display_init(lcdc);
+ if (ret < 0)
+ return ret;
+
+ ret = drm_simple_display_pipe_attach_bridge(&lcdc->pipe, bridge);
+ if (ret < 0)
+ DRM_DEV_ERROR(dev, "failed to attach bridge: %d\n", ret);
+
+ lcdc->connector = panel->connector;
+ return ret;
+}
+
+static int lcdc_create_output(struct lcdc *lcdc)
+{
+ struct device_node *endpoint;
+ struct device_node *np;
+ int ret;
+
+ /* port at 0/endpoint at 0 is the only port/endpoint */
+ np = lcdc->dev->of_node;
+ endpoint = of_graph_get_endpoint_by_regs(np, 0, 0);
+ if (!endpoint) {
+ DRM_DEV_ERROR(lcdc->dev, "failed to find endpoint node\n");
+ return -ENODEV;
+ }
+
+ lcdc_get_of_wiring(lcdc, endpoint);
+ of_node_put(endpoint);
+
+ ret = lcdc_attach_panel(lcdc);
+
+ return ret;
+}
+
+static const struct drm_mode_config_funcs mode_config_funcs = {
+ .fb_create = drm_gem_fb_create,
+ .atomic_check = drm_atomic_helper_check,
+ .atomic_commit = drm_atomic_helper_commit,
+};
+
+int atmel_lcdc_modeset_init(struct lcdc *lcdc)
+{
+ struct drm_device *drm;
+ struct device *dev;
+ int ret;
+
+ drm = &lcdc->drm;
+ dev = drm->dev;
+
+ drm_mode_config_init(drm);
+ ret = lcdc_create_output(lcdc);
+
+ if (ret) {
+ drm_mode_config_cleanup(drm);
+ return ret;
+ }
+
+ drm->mode_config.min_width = 0;
+ drm->mode_config.min_height = 0;
+ drm->mode_config.max_width = lcdc->desc->max_width;
+ drm->mode_config.max_height = lcdc->desc->max_height;
+ drm->mode_config.funcs = &mode_config_funcs;
+ drm->mode_config.quirk_addfb_rgb_to_bgr = !lcdc->wiring_reversed;
+
+ drm_mode_config_reset(drm);
+
+ return 0;
+}
+
+int atmel_lcdc_vblank_init(struct lcdc *lcdc)
+{
+ int ret;
+
+ ret = drm_vblank_init(&lcdc->drm, 1);
+ if (ret)
+ DRM_DEV_ERROR(lcdc->dev, "vblank init failed: %d\n", ret);
+
+ return ret;
+}
+
+void atmel_lcdc_vblank(struct lcdc *lcdc)
+{
+ drm_crtc_handle_vblank(&lcdc->pipe.crtc);
+}
+
+/*
+ * Start LCD Controller (DMA + PWR)
+ * Caller must hold enable_lock
+ */
+void atmel_lcdc_start(struct lcdc *lcdc)
+{
+ /* Enable DMA */
+ regmap_write(lcdc->mfd->regmap, ATMEL_LCDC_DMACON, ATMEL_LCDC_DMAEN);
+ /* Enable LCD */
+ regmap_write(lcdc->mfd->regmap, ATMEL_LCDC_PWRCON,
+ (lcdc->desc->guard_time << ATMEL_LCDC_GUARDT_OFFSET)
+ | ATMEL_LCDC_PWR);
+}
+
+/*
+ * Stop LCD Controller (PWR + DMA)
+ * Caller must hold enable_lock
+ */
+void atmel_lcdc_stop(struct lcdc *lcdc)
+{
+ unsigned int pwrcon;
+
+ might_sleep();
+
+ /* Turn off the LCD controller and the DMA controller */
+ regmap_write(lcdc->mfd->regmap, ATMEL_LCDC_PWRCON,
+ lcdc->desc->guard_time << ATMEL_LCDC_GUARDT_OFFSET);
+
+ regmap_write(lcdc->mfd->regmap, ATMEL_LCDC_DMACON, !(ATMEL_LCDC_DMAEN));
+
+ /* Wait for the LCDC core to become idle */
+ regmap_read_poll_timeout(lcdc->mfd->regmap, ATMEL_LCDC_PWRCON, pwrcon,
+ !(pwrcon & ATMEL_LCDC_BUSY), 100, 10000);
+}
--
2.20.1
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