drm/pl111: Support Nomadik LCDC variant

The Nomadik has a variant of the PL110 known as "Color LCD
Controller" LCDC. This variant has the same bit ordering as
the DRM subsystem (in difference from the other variants)
and adds a few bits for the control of 5551, 565 etc in the
control register. Notably it also adds a packed RGB888
24BPP mode.

We add support by detecting this variant and also adding a
small plug-in that will mux the LCDC out if the ASIC happens
to be muxed to the other graphics controller (they are
mutually exclusive).

Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20180621184450.25377-1-linus.walleij@linaro.org

diff --git a/drivers/gpu/drm/pl111/Makefile b/drivers/gpu/drm/pl111/Makefile
index 19a8189..0c70f0e 100644 (file)
--- a/drivers/gpu/drm/pl111/Makefile
+++ b/drivers/gpu/drm/pl111/Makefile
@@ -4,6 +4,7 @@ pl111_drm-y +=  pl111_display.o \
                pl111_drv.o
 
 pl111_drm-$(CONFIG_ARCH_VEXPRESS) += pl111_vexpress.o
+pl111_drm-$(CONFIG_ARCH_NOMADIK) += pl111_nomadik.o
 pl111_drm-$(CONFIG_DEBUG_FS) += pl111_debugfs.o
 
 obj-$(CONFIG_DRM_PL111) += pl111_drm.o

diff --git a/drivers/gpu/drm/pl111/pl111_display.c b/drivers/gpu/drm/pl111/pl111_display.c
index 19b0d00..a432eb7 100644 (file)
--- a/drivers/gpu/drm/pl111/pl111_display.c
+++ b/drivers/gpu/drm/pl111/pl111_display.c
@@ -223,48 +223,84 @@ static void pl111_display_enable(struct drm_simple_display_pipe *pipe,
 
        /* Hard-code TFT panel */
        cntl = CNTL_LCDEN | CNTL_LCDTFT | CNTL_LCDVCOMP(1);
+       /* On the ST Micro variant, assume all 24 bits are connected */
+       if (priv->variant->st_bitmux_control)
+               cntl |= CNTL_ST_CDWID_24;
 
-       /* Note that the the hardware's format reader takes 'r' from
+       /*
+        * Note that the the ARM hardware's format reader takes 'r' from
         * the low bit, while DRM formats list channels from high bit
-        * to low bit as you read left to right.
+        * to low bit as you read left to right. The ST Micro version of
+        * the PL110 (LCDC) however uses the standard DRM format.
         */
        switch (fb->format->format) {
+       case DRM_FORMAT_BGR888:
+               /* Only supported on the ST Micro variant */
+               if (priv->variant->st_bitmux_control)
+                       cntl |= CNTL_ST_LCDBPP24_PACKED | CNTL_BGR;
+               break;
+       case DRM_FORMAT_RGB888:
+               /* Only supported on the ST Micro variant */
+               if (priv->variant->st_bitmux_control)
+                       cntl |= CNTL_ST_LCDBPP24_PACKED;
+               break;
        case DRM_FORMAT_ABGR8888:
        case DRM_FORMAT_XBGR8888:
-               cntl |= CNTL_LCDBPP24;
+               if (priv->variant->st_bitmux_control)
+                       cntl |= CNTL_LCDBPP24 | CNTL_BGR;
+               else
+                       cntl |= CNTL_LCDBPP24;
                break;
        case DRM_FORMAT_ARGB8888:
        case DRM_FORMAT_XRGB8888:
-               cntl |= CNTL_LCDBPP24 | CNTL_BGR;
+               if (priv->variant->st_bitmux_control)
+                       cntl |= CNTL_LCDBPP24;
+               else
+                       cntl |= CNTL_LCDBPP24 | CNTL_BGR;
                break;
        case DRM_FORMAT_BGR565:
                if (priv->variant->is_pl110)
                        cntl |= CNTL_LCDBPP16;
+               else if (priv->variant->st_bitmux_control)
+                       cntl |= CNTL_LCDBPP16 | CNTL_ST_1XBPP_565 | CNTL_BGR;
                else
                        cntl |= CNTL_LCDBPP16_565;
                break;
        case DRM_FORMAT_RGB565:
                if (priv->variant->is_pl110)
-                       cntl |= CNTL_LCDBPP16;
+                       cntl |= CNTL_LCDBPP16 | CNTL_BGR;
+               else if (priv->variant->st_bitmux_control)
+                       cntl |= CNTL_LCDBPP16 | CNTL_ST_1XBPP_565;
                else
-                       cntl |= CNTL_LCDBPP16_565;
-               cntl |= CNTL_BGR;
+                       cntl |= CNTL_LCDBPP16_565 | CNTL_BGR;
                break;
        case DRM_FORMAT_ABGR1555:
        case DRM_FORMAT_XBGR1555:
                cntl |= CNTL_LCDBPP16;
+               if (priv->variant->st_bitmux_control)
+                       cntl |= CNTL_ST_1XBPP_5551 | CNTL_BGR;
                break;
        case DRM_FORMAT_ARGB1555:
        case DRM_FORMAT_XRGB1555:
-               cntl |= CNTL_LCDBPP16 | CNTL_BGR;
+               cntl |= CNTL_LCDBPP16;
+               if (priv->variant->st_bitmux_control)
+                       cntl |= CNTL_ST_1XBPP_5551;
+               else
+                       cntl |= CNTL_BGR;
                break;
        case DRM_FORMAT_ABGR4444:
        case DRM_FORMAT_XBGR4444:
                cntl |= CNTL_LCDBPP16_444;
+               if (priv->variant->st_bitmux_control)
+                       cntl |= CNTL_ST_1XBPP_444 | CNTL_BGR;
                break;
        case DRM_FORMAT_ARGB4444:
        case DRM_FORMAT_XRGB4444:
-               cntl |= CNTL_LCDBPP16_444 | CNTL_BGR;
+               cntl |= CNTL_LCDBPP16_444;
+               if (priv->variant->st_bitmux_control)
+                       cntl |= CNTL_ST_1XBPP_444;
+               else
+                       cntl |= CNTL_BGR;
                break;
        default:
                WARN_ONCE(true, "Unknown FB format 0x%08x\n",

diff --git a/drivers/gpu/drm/pl111/pl111_drm.h b/drivers/gpu/drm/pl111/pl111_drm.h
index ce4501d..1aa015c 100644 (file)
--- a/drivers/gpu/drm/pl111/pl111_drm.h
+++ b/drivers/gpu/drm/pl111/pl111_drm.h
@@ -36,11 +36,14 @@ struct drm_minor;
  * struct pl111_variant_data - encodes IP differences
  * @name: the name of this variant
  * @is_pl110: this is the early PL110 variant
+ * @is_lcdc: this is the ST Microelectronics Nomadik LCDC variant
  * @external_bgr: this is the Versatile Pl110 variant with external
  *     BGR/RGB routing
  * @broken_clockdivider: the clock divider is broken and we need to
  *     use the supplied clock directly
  * @broken_vblank: the vblank IRQ is broken on this variant
+ * @st_bitmux_control: this variant is using the ST Micro bitmux
+ *     extensions to the control register
  * @formats: array of supported pixel formats on this variant
  * @nformats: the length of the array of supported pixel formats
  * @fb_bpp: desired bits per pixel on the default framebuffer
@@ -48,9 +51,11 @@ struct drm_minor;
 struct pl111_variant_data {
        const char *name;
        bool is_pl110;
+       bool is_lcdc;
        bool external_bgr;
        bool broken_clockdivider;
        bool broken_vblank;
+       bool st_bitmux_control;
        const u32 *formats;
        unsigned int nformats;
        unsigned int fb_bpp;

diff --git a/drivers/gpu/drm/pl111/pl111_drv.c b/drivers/gpu/drm/pl111/pl111_drv.c
index 454ff08..054b936 100644 (file)
--- a/drivers/gpu/drm/pl111/pl111_drv.c
+++ b/drivers/gpu/drm/pl111/pl111_drv.c
@@ -75,6 +75,7 @@
 
 #include "pl111_drm.h"
 #include "pl111_versatile.h"
+#include "pl111_nomadik.h"
 
 #define DRIVER_DESC      "DRM module for PL111"
 
@@ -288,8 +289,8 @@ static int pl111_amba_probe(struct amba_device *amba_dev,
                priv->memory_bw = 0;
        }
 
-       /* The two variants swap this register */
-       if (variant->is_pl110) {
+       /* The two main variants swap this register */
+       if (variant->is_pl110 || variant->is_lcdc) {
                priv->ienb = CLCD_PL110_IENB;
                priv->ctrl = CLCD_PL110_CNTL;
        } else {
@@ -308,6 +309,7 @@ static int pl111_amba_probe(struct amba_device *amba_dev,
        ret = pl111_versatile_init(dev, priv);
        if (ret)
                goto dev_unref;
+       pl111_nomadik_init(dev);
 
        /* turn off interrupts before requesting the irq */
        writel(0, priv->regs + priv->ienb);
@@ -400,16 +402,50 @@ static const struct pl111_variant_data pl111_variant = {
        .fb_bpp = 32,
 };
 
+static const u32 pl110_nomadik_pixel_formats[] = {
+       DRM_FORMAT_RGB888,
+       DRM_FORMAT_BGR888,
+       DRM_FORMAT_ABGR8888,
+       DRM_FORMAT_XBGR8888,
+       DRM_FORMAT_ARGB8888,
+       DRM_FORMAT_XRGB8888,
+       DRM_FORMAT_BGR565,
+       DRM_FORMAT_RGB565,
+       DRM_FORMAT_ABGR1555,
+       DRM_FORMAT_XBGR1555,
+       DRM_FORMAT_ARGB1555,
+       DRM_FORMAT_XRGB1555,
+       DRM_FORMAT_ABGR4444,
+       DRM_FORMAT_XBGR4444,
+       DRM_FORMAT_ARGB4444,
+       DRM_FORMAT_XRGB4444,
+};
+
+static const struct pl111_variant_data pl110_nomadik_variant = {
+       .name = "LCDC (PL110 Nomadik)",
+       .formats = pl110_nomadik_pixel_formats,
+       .nformats = ARRAY_SIZE(pl110_nomadik_pixel_formats),
+       .is_lcdc = true,
+       .st_bitmux_control = true,
+       .broken_vblank = true,
+       .fb_bpp = 16,
+};
+
 static const struct amba_id pl111_id_table[] = {
        {
                .id = 0x00041110,
                .mask = 0x000fffff,
-               .data = (void*)&pl110_variant,
+               .data = (void *)&pl110_variant,
+       },
+       {
+               .id = 0x00180110,
+               .mask = 0x00fffffe,
+               .data = (void *)&pl110_nomadik_variant,
        },
        {
                .id = 0x00041111,
                .mask = 0x000fffff,
-               .data = (void*)&pl111_variant,
+               .data = (void *)&pl111_variant,
        },
        {0, 0},
 };

diff --git a/drivers/gpu/drm/pl111/pl111_nomadik.c b/drivers/gpu/drm/pl111/pl111_nomadik.c
new file mode 100644 (file)
index 0000000..6f385e5
--- /dev/null
+++ b/drivers/gpu/drm/pl111/pl111_nomadik.c
@@ -0,0 +1,36 @@
+// SPDX-License-Identifier: GPL-2.0+
+#include <linux/device.h>
+#include <linux/regmap.h>
+#include <linux/mfd/syscon.h>
+#include <linux/bitops.h>
+#include <linux/module.h>
+#include "pl111_nomadik.h"
+
+#define PMU_CTRL_OFFSET 0x0000
+#define PMU_CTRL_LCDNDIF BIT(26)
+
+void pl111_nomadik_init(struct device *dev)
+{
+       struct regmap *pmu_regmap;
+
+       /*
+        * Just bail out of this is not found, we could be running
+        * multiplatform on something else than Nomadik.
+        */
+       pmu_regmap =
+               syscon_regmap_lookup_by_compatible("stericsson,nomadik-pmu");
+       if (IS_ERR(pmu_regmap))
+               return;
+
+       /*
+        * This bit in the PMU controller multiplexes the two graphics
+        * blocks found in the Nomadik STn8815. The other one is called
+        * MDIF (Master Display Interface) and gets muxed out here.
+        */
+       regmap_update_bits(pmu_regmap,
+                          PMU_CTRL_OFFSET,
+                          PMU_CTRL_LCDNDIF,
+                          0);
+       dev_info(dev, "set Nomadik PMU mux to CLCD mode\n");
+}
+EXPORT_SYMBOL_GPL(pl111_nomadik_init);

diff --git a/drivers/gpu/drm/pl111/pl111_nomadik.h b/drivers/gpu/drm/pl111/pl111_nomadik.h
new file mode 100644 (file)
index 0000000..19d663d
--- /dev/null
+++ b/drivers/gpu/drm/pl111/pl111_nomadik.h
@@ -0,0 +1,18 @@
+// SPDX-License-Identifier: GPL-2.0+
+#include <linux/device.h>
+
+#ifndef PL111_NOMADIK_H
+#define PL111_NOMADIK_H
+#endif
+
+#ifdef CONFIG_ARCH_NOMADIK
+
+void pl111_nomadik_init(struct device *dev);
+
+#else
+
+static inline void pl111_nomadik_init(struct device *dev)
+{
+}
+
+#endif