drm/tve200: Add new driver for TVE200

This adds a new DRM driver for the Faraday Technology TVE200
block. This "TV Encoder" encodes a ITU-T BT.656 stream and can
be found in the StorLink SL3516 (later Cortina Systems CS3516)
as well as the Grain Media GM8180.

I do not have definitive word from anyone at Faraday that this
IP block is theirs, but it bears the hallmark of their 3-digit
version code (200) and is used in two SoCs from completely
different companies. (Grain Media was fully owned by Faraday
until it was transferred to NovoTek this january, and
Faraday did lots of work on the StorLink SoCs.)

The D-Link DIR-685 uses this in connection with the Ilitek
ILI9322 panel driver that supports BT.656 input, while the
GM8180 apparently has been used with the Cirrus Logic CS4954
digital video encoder. The oldest user seems to be
something called Techwall 2835.

This driver is heavily inspired by Eric Anholt's PL111
driver and therefore I have mentioned all the ancestor authors
in the header file.

Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20170820100557.24991-2-linus.walleij@linaro.org

1 files changed, 278 insertions, 0 deletions

diff --git a/drivers/gpu/drm/tve200/tve200_drv.c b/drivers/gpu/drm/tve200/tve200_drv.c
new file mode 100644
index 000000000000..fe742106db4e
--- /dev/null
+++ b/drivers/gpu/drm/tve200/tve200_drv.c
@@ -0,0 +1,278 @@
+/*
+ * Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org>
+ * Parts of this file were based on sources as follows:
+ *
+ * Copyright (C) 2006-2008 Intel Corporation
+ * Copyright (C) 2007 Amos Lee <amos_lee@storlinksemi.com>
+ * Copyright (C) 2007 Dave Airlie <airlied@linux.ie>
+ * Copyright (C) 2011 Texas Instruments
+ * Copyright (C) 2017 Eric Anholt
+ *
+ * This program is free software and is provided to you under the terms of the
+ * GNU General Public License version 2 as published by the Free Software
+ * Foundation, and any use by you of this program is subject to the terms of
+ * such GNU licence.
+ */
+
+/**
+ * DOC: Faraday TV Encoder TVE200 DRM Driver
+ *
+ * The Faraday TV Encoder TVE200 is also known as the Gemini TV Interface
+ * Controller (TVC) and is found in the Gemini Chipset from Storlink
+ * Semiconductor (later Storm Semiconductor, later Cortina Systems)
+ * but also in the Grain Media GM8180 chipset. On the Gemini the module
+ * is connected to 8 data lines and a single clock line, comprising an
+ * 8-bit BT.656 interface.
+ *
+ * This is a very basic YUV display driver. The datasheet specifies that
+ * it supports the ITU BT.656 standard. It requires a 27 MHz clock which is
+ * the hallmark of any TV encoder supporting both PAL and NTSC.
+ *
+ * This driver exposes a standard KMS interface for this TV encoder.
+ */
+
+#include <linux/clk.h>
+#include <linux/dma-buf.h>
+#include <linux/irq.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/shmem_fs.h>
+#include <linux/slab.h>
+#include <linux/version.h>
+
+#include <drm/drmP.h>
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_crtc_helper.h>
+#include <drm/drm_gem_cma_helper.h>
+#include <drm/drm_fb_cma_helper.h>
+#include <drm/drm_panel.h>
+
+#include "tve200_drm.h"
+
+#define DRIVER_DESC      "DRM module for Faraday TVE200"
+
+static const struct drm_mode_config_funcs mode_config_funcs = {
+	.fb_create = drm_fb_cma_create,
+	.atomic_check = drm_atomic_helper_check,
+	.atomic_commit = drm_atomic_helper_commit,
+};
+
+static int tve200_modeset_init(struct drm_device *dev)
+{
+	struct drm_mode_config *mode_config;
+	struct tve200_drm_dev_private *priv = dev->dev_private;
+	int ret = 0;
+
+	drm_mode_config_init(dev);
+	mode_config = &dev->mode_config;
+	mode_config->funcs = &mode_config_funcs;
+	mode_config->min_width = 352;
+	mode_config->max_width = 720;
+	mode_config->min_height = 240;
+	mode_config->max_height = 576;
+
+	ret = tve200_connector_init(dev);
+	if (ret) {
+		dev_err(dev->dev, "Failed to create tve200_drm_connector\n");
+		goto out_config;
+	}
+
+	/*
+	 * Don't actually attach if we didn't find a drm_panel
+	 * attached to us.
+	 */
+	if (!priv->connector.panel) {
+		dev_info(dev->dev,
+			 "deferring due to lack of DRM panel device\n");
+		ret = -EPROBE_DEFER;
+		goto out_config;
+	}
+	dev_info(dev->dev, "attached to panel %s\n",
+		 dev_name(priv->connector.panel->dev));
+
+	ret = tve200_display_init(dev);
+	if (ret) {
+		dev_err(dev->dev, "failed to init display\n");
+		goto out_config;
+	}
+
+	ret = drm_vblank_init(dev, 1);
+	if (ret) {
+		dev_err(dev->dev, "failed to init vblank\n");
+		goto out_config;
+	}
+
+	drm_mode_config_reset(dev);
+
+	/*
+	 * Passing in 16 here will make the RGB656 mode the default
+	 * Passing in 32 will use XRGB8888 mode
+	 */
+	priv->fbdev = drm_fbdev_cma_init(dev, 16,
+					 dev->mode_config.num_connector);
+	drm_kms_helper_poll_init(dev);
+
+	goto finish;
+
+out_config:
+	drm_mode_config_cleanup(dev);
+finish:
+	return ret;
+}
+
+DEFINE_DRM_GEM_CMA_FOPS(drm_fops);
+
+static void tve200_lastclose(struct drm_device *dev)
+{
+	struct tve200_drm_dev_private *priv = dev->dev_private;
+
+	drm_fbdev_cma_restore_mode(priv->fbdev);
+}
+
+static struct drm_driver tve200_drm_driver = {
+	.driver_features =
+		DRIVER_MODESET | DRIVER_GEM | DRIVER_PRIME | DRIVER_ATOMIC,
+	.lastclose = tve200_lastclose,
+	.ioctls = NULL,
+	.fops = &drm_fops,
+	.name = "tve200",
+	.desc = DRIVER_DESC,
+	.date = "20170703",
+	.major = 1,
+	.minor = 0,
+	.patchlevel = 0,
+	.dumb_create = drm_gem_cma_dumb_create,
+	.gem_free_object_unlocked = drm_gem_cma_free_object,
+	.gem_vm_ops = &drm_gem_cma_vm_ops,
+
+	.enable_vblank = tve200_enable_vblank,
+	.disable_vblank = tve200_disable_vblank,
+
+	.prime_handle_to_fd = drm_gem_prime_handle_to_fd,
+	.prime_fd_to_handle = drm_gem_prime_fd_to_handle,
+	.gem_prime_import = drm_gem_prime_import,
+	.gem_prime_export = drm_gem_prime_export,
+	.gem_prime_get_sg_table	= drm_gem_cma_prime_get_sg_table,
+	.gem_prime_import_sg_table = drm_gem_cma_prime_import_sg_table,
+	.gem_prime_vmap = drm_gem_cma_prime_vmap,
+	.gem_prime_vunmap = drm_gem_cma_prime_vunmap,
+	.gem_prime_mmap = drm_gem_cma_prime_mmap,
+};
+
+static int tve200_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct tve200_drm_dev_private *priv;
+	struct drm_device *drm;
+	struct resource *res;
+	int irq;
+	int ret;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	drm = drm_dev_alloc(&tve200_drm_driver, dev);
+	if (IS_ERR(drm))
+		return PTR_ERR(drm);
+	platform_set_drvdata(pdev, drm);
+	priv->drm = drm;
+	drm->dev_private = priv;
+
+	/* Clock the silicon so we can access the registers */
+	priv->pclk = devm_clk_get(dev, "PCLK");
+	if (IS_ERR(priv->pclk)) {
+		dev_err(dev, "unable to get PCLK\n");
+		ret = PTR_ERR(priv->pclk);
+		goto dev_unref;
+	}
+	ret = clk_prepare_enable(priv->pclk);
+	if (ret) {
+		dev_err(dev, "failed to enable PCLK\n");
+		goto dev_unref;
+	}
+
+	/* This clock is for the pixels (27MHz) */
+	priv->clk = devm_clk_get(dev, "TVE");
+	if (IS_ERR(priv->clk)) {
+		dev_err(dev, "unable to get TVE clock\n");
+		ret = PTR_ERR(priv->clk);
+		goto clk_disable;
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	priv->regs = devm_ioremap_resource(dev, res);
+	if (!priv->regs) {
+		dev_err(dev, "%s failed mmio\n", __func__);
+		ret = -EINVAL;
+		goto clk_disable;
+	}
+
+	irq = platform_get_irq(pdev, 0);
+	if (!irq) {
+		ret = -EINVAL;
+		goto clk_disable;
+	}
+
+	/* turn off interrupts before requesting the irq */
+	writel(0, priv->regs + TVE200_INT_EN);
+
+	ret = devm_request_irq(dev, irq, tve200_irq, 0, "tve200", priv);
+	if (ret) {
+		dev_err(dev, "failed to request irq %d\n", ret);
+		goto clk_disable;
+	}
+
+	ret = tve200_modeset_init(drm);
+	if (ret)
+		goto clk_disable;
+
+	ret = drm_dev_register(drm, 0);
+	if (ret < 0)
+		goto clk_disable;
+
+	return 0;
+
+clk_disable:
+	clk_disable_unprepare(priv->pclk);
+dev_unref:
+	drm_dev_unref(drm);
+	return ret;
+}
+
+static int tve200_remove(struct platform_device *pdev)
+{
+	struct drm_device *drm = platform_get_drvdata(pdev);
+	struct tve200_drm_dev_private *priv = drm->dev_private;
+
+	drm_dev_unregister(drm);
+	if (priv->fbdev)
+		drm_fbdev_cma_fini(priv->fbdev);
+	drm_mode_config_cleanup(drm);
+	clk_disable_unprepare(priv->pclk);
+	drm_dev_unref(drm);
+
+	return 0;
+}
+
+static const struct of_device_id tve200_of_match[] = {
+	{
+		.compatible = "faraday,tve200",
+	},
+	{},
+};
+
+static struct platform_driver tve200_driver = {
+	.driver = {
+		.name           = "tve200",
+		.of_match_table = of_match_ptr(tve200_of_match),
+	},
+	.probe = tve200_probe,
+	.remove = tve200_remove,
+};
+module_platform_driver(tve200_driver);
+
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>");
+MODULE_LICENSE("GPL");