DRM: Armada: Add Armada DRM driver

This patch adds support for the pair of LCD controllers on the Marvell
Armada 510 SoCs.  This driver supports:
- multiple contiguous scanout buffers for video and graphics
- shm backed cacheable buffer objects for X pixmaps for Vivante GPU
  acceleration
- dual lcd0 and lcd1 crt operation
- video overlay on each LCD crt via DRM planes
- page flipping of the main scanout buffers
- DRM prime for buffer export/import

This driver is trivial to extend to other Armada SoCs.

Included in this commit is the core driver with no output support; output
support is platform and encoder driver dependent.

Tested-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Reviewed-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

22 files changed, 3953 insertions, 0 deletions

diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index 955555d6ec88..3b5176dd1c86 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -225,6 +225,8 @@ source "drivers/gpu/drm/mgag200/Kconfig"
 
 source "drivers/gpu/drm/cirrus/Kconfig"
 
+source "drivers/gpu/drm/armada/Kconfig"
+
 source "drivers/gpu/drm/rcar-du/Kconfig"
 
 source "drivers/gpu/drm/shmobile/Kconfig"
diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index f089adfe70ee..385f460459d4 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -49,6 +49,7 @@ obj-$(CONFIG_DRM_EXYNOS) +=exynos/
 obj-$(CONFIG_DRM_GMA500) += gma500/
 obj-$(CONFIG_DRM_UDL) += udl/
 obj-$(CONFIG_DRM_AST) += ast/
+obj-$(CONFIG_DRM_ARMADA) += armada/
 obj-$(CONFIG_DRM_RCAR_DU) += rcar-du/
 obj-$(CONFIG_DRM_SHMOBILE) +=shmobile/
 obj-$(CONFIG_DRM_OMAP)  += omapdrm/
diff --git a/drivers/gpu/drm/armada/Kconfig b/drivers/gpu/drm/armada/Kconfig
new file mode 100644
index 000000000000..c7a0a944acfe
--- /dev/null
+++ b/drivers/gpu/drm/armada/Kconfig
@@ -0,0 +1,15 @@
+config DRM_ARMADA
+        tristate "DRM support for Marvell Armada SoCs"
+        depends on DRM && HAVE_CLK
+        select FB_CFB_FILLRECT
+        select FB_CFB_COPYAREA
+        select FB_CFB_IMAGEBLIT
+        select DRM_KMS_HELPER
+        help
+          Support the "LCD" controllers found on the Marvell Armada 510
+          devices.  There are two controllers on the device, each controller
+          supports graphics and video overlays.
+
+          This driver provides no built-in acceleration; acceleration is
+          performed by other IP found on the SoC.  This driver provides
+          kernel mode setting and buffer management to userspace.
diff --git a/drivers/gpu/drm/armada/Makefile b/drivers/gpu/drm/armada/Makefile
new file mode 100644
index 000000000000..d6f43e06150a
--- /dev/null
+++ b/drivers/gpu/drm/armada/Makefile
@@ -0,0 +1,7 @@
+armada-y        := armada_crtc.o armada_drv.o armada_fb.o armada_fbdev.o \
+                   armada_gem.o armada_output.o armada_overlay.o \
+                   armada_slave.o
+armada-y        += armada_510.o
+armada-$(CONFIG_DEBUG_FS) += armada_debugfs.o
+
+obj-$(CONFIG_DRM_ARMADA) := armada.o
diff --git a/drivers/gpu/drm/armada/armada_510.c b/drivers/gpu/drm/armada/armada_510.c
new file mode 100644
index 000000000000..a016888acd29
--- /dev/null
+++ b/drivers/gpu/drm/armada/armada_510.c
@@ -0,0 +1,86 @@
+/*
+ * Copyright (C) 2012 Russell King
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Armada 510 (aka Dove) variant support
+ */
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <drm/drmP.h>
+#include <drm/drm_crtc_helper.h>
+#include "armada_crtc.h"
+#include "armada_drm.h"
+#include "armada_hw.h"
+
+static int armada510_init(struct armada_private *priv, struct device *dev)
+{
+        priv->extclk[0] = devm_clk_get(dev, "ext_ref_clk_1");
+
+        if (IS_ERR(priv->extclk[0]) && PTR_ERR(priv->extclk[0]) == -ENOENT)
+                priv->extclk[0] = ERR_PTR(-EPROBE_DEFER);
+
+        return PTR_RET(priv->extclk[0]);
+}
+
+static int armada510_crtc_init(struct armada_crtc *dcrtc)
+{
+        /* Lower the watermark so to eliminate jitter at higher bandwidths */
+        armada_updatel(0x20, (1 << 11) | 0xff, dcrtc->base + LCD_CFG_RDREG4F);
+        return 0;
+}
+
+/*
+ * Armada510 specific SCLK register selection.
+ * This gets called with sclk = NULL to test whether the mode is
+ * supportable, and again with sclk != NULL to set the clocks up for
+ * that.  The former can return an error, but the latter is expected
+ * not to.
+ *
+ * We currently are pretty rudimentary here, always selecting
+ * EXT_REF_CLK_1 for LCD0 and erroring LCD1.  This needs improvement!
+ */
+static int armada510_crtc_compute_clock(struct armada_crtc *dcrtc,
+        const struct drm_display_mode *mode, uint32_t *sclk)
+{
+        struct armada_private *priv = dcrtc->crtc.dev->dev_private;
+        struct clk *clk = priv->extclk[0];
+        int ret;
+
+        if (dcrtc->num == 1)
+                return -EINVAL;
+
+        if (IS_ERR(clk))
+                return PTR_ERR(clk);
+
+        if (dcrtc->clk != clk) {
+                ret = clk_prepare_enable(clk);
+                if (ret)
+                        return ret;
+                dcrtc->clk = clk;
+        }
+
+        if (sclk) {
+                uint32_t rate, ref, div;
+
+                rate = mode->clock * 1000;
+                ref = clk_round_rate(clk, rate);
+                div = DIV_ROUND_UP(ref, rate);
+                if (div < 1)
+                        div = 1;
+
+                clk_set_rate(clk, ref);
+                *sclk = div | SCLK_510_EXTCLK1;
+        }
+
+        return 0;
+}
+
+const struct armada_variant armada510_ops = {
+        .has_spu_adv_reg = true,
+        .init = armada510_init,
+        .crtc_init = armada510_crtc_init,
+        .crtc_compute_clock = armada510_crtc_compute_clock,
+};
diff --git a/drivers/gpu/drm/armada/armada_crtc.c b/drivers/gpu/drm/armada/armada_crtc.c
new file mode 100644
index 000000000000..7b379fdb4e8c
--- /dev/null
+++ b/drivers/gpu/drm/armada/armada_crtc.c
@@ -0,0 +1,861 @@
+/*
+ * Copyright (C) 2012 Russell King
+ *  Rewritten from the dovefb driver, and Armada510 manuals.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/clk.h>
+#include <drm/drmP.h>
+#include <drm/drm_crtc_helper.h>
+#include "armada_crtc.h"
+#include "armada_drm.h"
+#include "armada_fb.h"
+#include "armada_gem.h"