[PATCH] drm/armada: add mmp2 support

* [PATCH] drm/armada: add mmp2 support
@ 2019-01-21  6:03 Lubomir Rintel
  2019-01-22 19:10 ` Russell King - ARM Linux admin
  0 siblings, 1 reply; 3+ messages in thread
From: Lubomir Rintel @ 2019-01-21  6:03 UTC (permalink / raw)
  To: Russell King
  Cc: David Airlie, Daniel Vetter, dri-devel, linux-kernel, Lubomir Rintel

Heavily based on the Armada 510 (Dove) support. Like with 510 support, this
also just supports a single source clock -- the "Display 1" clock as
generated by the APMU. This one was chosen because the OLPC XO 1.75 laptop
uses it for its internal panel.

If anyone uses this to drive a MIPI or HDMI encoder, they may want to
extend this to choose a different source for the pixel clock -- it should
be a reasonably straightforward thing to do.

The data sheet is not available, but James Cameron of OLPC kindly
provided some details about the LCD_SCLK_DIV register.

Link: https://lists.freedesktop.org/archives/dri-devel/2018-December/201021.html
Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
---
 drivers/gpu/drm/armada/Makefile      |  1 +
 drivers/gpu/drm/armada/armada_610.c  | 93 ++++++++++++++++++++++++++++
 drivers/gpu/drm/armada/armada_crtc.c |  4 ++
 drivers/gpu/drm/armada/armada_drm.h  |  1 +
 drivers/gpu/drm/armada/armada_hw.h   | 10 +++
 5 files changed, 109 insertions(+)
 create mode 100644 drivers/gpu/drm/armada/armada_610.c

diff --git a/drivers/gpu/drm/armada/Makefile b/drivers/gpu/drm/armada/Makefile
index 9bc3c3213724..5bbf86324cda 100644
--- a/drivers/gpu/drm/armada/Makefile
+++ b/drivers/gpu/drm/armada/Makefile
@@ -2,6 +2,7 @@
 armada-y	:= armada_crtc.o armada_drv.o armada_fb.o armada_fbdev.o \
 		   armada_gem.o armada_overlay.o armada_plane.o armada_trace.o
 armada-y	+= armada_510.o
+armada-y	+= armada_610.o
 armada-$(CONFIG_DEBUG_FS) += armada_debugfs.o
 
 obj-$(CONFIG_DRM_ARMADA) := armada.o
diff --git a/drivers/gpu/drm/armada/armada_610.c b/drivers/gpu/drm/armada/armada_610.c
new file mode 100644
index 000000000000..278b204038ea
--- /dev/null
+++ b/drivers/gpu/drm/armada/armada_610.c
@@ -0,0 +1,93 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2012 Russell King
+ * Copyright (C) 2018,2019 Lubomir Rintel
+ *
+ * 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 MMP2 variant support
+ */
+#include <linux/clk.h>
+#include <drm/drm_modes.h>
+#include <drm/drm_crtc.h>
+#include "armada_crtc.h"
+#include "armada_drm.h"
+#include "armada_hw.h"
+
+static int armada610_crtc_init(struct armada_crtc *dcrtc, struct device *dev)
+{
+	struct clk *clk;
+
+	clk = devm_clk_get(dev, "disp0");
+	if (IS_ERR(clk))
+		return PTR_ERR(clk) == -ENOENT ? -EPROBE_DEFER : PTR_ERR(clk);
+
+	dcrtc->extclk[0] = clk;
+
+	return 0;
+}
+
+/*
+ * 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.
+ */
+static int armada610_crtc_compute_clock(struct armada_crtc *dcrtc,
+	const struct drm_display_mode *mode, uint32_t *sclk)
+{
+	struct clk *clk = dcrtc->extclk[0];
+	uint32_t ret, rate, ref, div;
+
+	if (IS_ERR(clk))
+		return PTR_ERR(clk);
+
+	rate = mode->clock * 1000;
+	ref = clk_get_rate(clk);
+	div = DIV_ROUND_UP(ref, rate);
+
+	if (div < 2)
+		return -EINVAL;
+
+	if (dcrtc->clk != clk) {
+		ret = clk_prepare_enable(clk);
+		if (ret)
+			return ret;
+		dcrtc->clk = clk;
+	}
+
+	if (sclk) {
+		*sclk = 0x00001000; /* No idea */
+		*sclk |= 1 << 8; /* MIPI clock bypass */
+		*sclk |= SCLK_610_DISP0;
+		*sclk |= div;
+	}
+
+	return 0;
+}
+
+static void armada610_crtc_disable(struct armada_crtc *dcrtc)
+{
+	if (!IS_ERR(dcrtc->clk)) {
+		clk_disable_unprepare(dcrtc->clk);
+		dcrtc->clk = ERR_PTR(-EINVAL);
+	}
+}
+
+static void armada610_crtc_enable(struct armada_crtc *dcrtc,
+	const struct drm_display_mode *mode)
+{
+	if (IS_ERR(dcrtc->clk)) {
+		dcrtc->clk = dcrtc->extclk[0];
+		WARN_ON(clk_prepare_enable(dcrtc->clk));
+	}
+}
+
+const struct armada_variant armada610_ops = {
+	.init = armada610_crtc_init,
+	.compute_clock = armada610_crtc_compute_clock,
+	.disable = armada610_crtc_disable,
+	.enable = armada610_crtc_enable,
+};
diff --git a/drivers/gpu/drm/armada/armada_crtc.c b/drivers/gpu/drm/armada/armada_crtc.c
index da9360688b55..927be8898eb7 100644
--- a/drivers/gpu/drm/armada/armada_crtc.c
+++ b/drivers/gpu/drm/armada/armada_crtc.c
@@ -884,6 +884,10 @@ static const struct of_device_id armada_lcd_of_match[] = {
 		.compatible	= "marvell,dove-lcd",
 		.data		= &armada510_ops,
 	},
+	{
+		.compatible	= "marvell,mmp2-lcd",
+		.data		= &armada610_ops,
+	},
 	{}
 };
 MODULE_DEVICE_TABLE(of, armada_lcd_of_match);
diff --git a/drivers/gpu/drm/armada/armada_drm.h b/drivers/gpu/drm/armada/armada_drm.h
index f09083ff15d3..7cbcf33d0304 100644
--- a/drivers/gpu/drm/armada/armada_drm.h
+++ b/drivers/gpu/drm/armada/armada_drm.h
@@ -52,6 +52,7 @@ struct armada_variant {
 
 /* Variant ops */
 extern const struct armada_variant armada510_ops;
+extern const struct armada_variant armada610_ops;
 
 struct armada_private {
 	struct drm_device	drm;
diff --git a/drivers/gpu/drm/armada/armada_hw.h b/drivers/gpu/drm/armada/armada_hw.h
index 277580b36758..df2ff77b9c07 100644
--- a/drivers/gpu/drm/armada/armada_hw.h
+++ b/drivers/gpu/drm/armada/armada_hw.h
@@ -205,6 +205,16 @@ enum {
 	SCLK_510_FRAC_DIV_MASK	= 0xfff << 16,
 	SCLK_510_INT_DIV_MASK	= 0xffff << 0,
 
+	/* Armada 610 */
+	SCLK_610_AXI		= 0x0 << 30,
+	SCLK_610_DISP0		= 0x1 << 30,	/* LCD Display 1 */
+	SCLK_610_DISP1		= 0x2 << 30,	/* LCD Display 2 */
+	SCLK_610_PLL		= 0x3 << 30,	/* HDMI PLL clock */
+	SCLK_610_PANEL_CLK_DIS	= 0x1 << 28,	/* 1 = panel clock disabled */
+	SCLK_610_FRAC_DIV_MASK	= 0xfff << 16,
+	SCLK_610_MIPI_DIV_MASK	= 0xf << 8,	/* 0 = off, 1 = bypass, ... */
+	SCLK_610_INT_DIV_MASK	= 0xff << 0,
+
 	/* Armada 16x */
 	SCLK_16X_AHB		= 0x0 << 28,
 	SCLK_16X_PCLK		= 0x1 << 28,
-- 
2.20.1


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