powerpc/85xx: Enable display support for t1042rdb

Add a diu_ops implementation for t1042rdb.
Signed-off-by: Jason Jin <jason.jin@nxp.com>
[Meng Yi: Made file t1042rdb-specific]
Signed-off-by: Meng Yi <meng.yi@nxp.com>
[scottwood: clean up commit message]
Signed-off-by: Scott Wood <oss@buserror.net>

arch/powerpc/platforms/85xx/Makefile

@@ -22,6 +22,7 @@ obj-$(CONFIG_P1022_RDK)   += p1022_rdk.o
 obj-$(CONFIG_P1023_RDB)   += p1023_rdb.o
 obj-$(CONFIG_TWR_P102x)   += twr_p102x.o
 obj-$(CONFIG_CORENET_GENERIC)   += corenet_generic.o
+obj-$(CONFIG_FB_FSL_DIU)	+= t1042rdb_diu.o
 obj-$(CONFIG_STX_GP3)	  += stx_gp3.o
 obj-$(CONFIG_TQM85xx)	  += tqm85xx.o
 obj-$(CONFIG_SBC8548)     += sbc8548.o

arch/powerpc/platforms/85xx/t1042rdb_diu.c

+/*
+ * T1042 platform DIU operation
+ *
+ * Copyright 2014 Freescale Semiconductor Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+
+#include <sysdev/fsl_soc.h>
+
+/*DIU Pixel ClockCR offset in scfg*/
+#define CCSR_SCFG_PIXCLKCR      0x28
+
+/* DIU Pixel Clock bits of the PIXCLKCR */
+#define PIXCLKCR_PXCKEN		0x80000000
+#define PIXCLKCR_PXCKINV	0x40000000
+#define PIXCLKCR_PXCKDLY	0x0000FF00
+#define PIXCLKCR_PXCLK_MASK	0x00FF0000
+
+/* Some CPLD register definitions */
+#define CPLD_DIUCSR		0x16
+#define CPLD_DIUCSR_DVIEN	0x80
+#define CPLD_DIUCSR_BACKLIGHT	0x0f
+
+struct device_node *cpld_node;
+
+/**
+ * t1042rdb_set_monitor_port: switch the output to a different monitor port
+ */
+static void t1042rdb_set_monitor_port(enum fsl_diu_monitor_port port)
+{
+	static void __iomem *cpld_base;
+
+	cpld_base = of_iomap(cpld_node, 0);
+	if (!cpld_base) {
+		pr_err("%s: Could not map cpld registers\n", __func__);
+		goto exit;
+	}
+
+	switch (port) {
+	case FSL_DIU_PORT_DVI:
+		/* Enable the DVI(HDMI) port, disable the DFP and
+		 * the backlight
+		 */
+		clrbits8(cpld_base + CPLD_DIUCSR, CPLD_DIUCSR_DVIEN);
+		break;
+	case FSL_DIU_PORT_LVDS:
+		/*
+		 * LVDS also needs backlight enabled, otherwise the display
+		 * will be blank.
+		 */
+		/* Enable the DFP port, disable the DVI*/
+		setbits8(cpld_base + CPLD_DIUCSR, 0x01 << 8);
+		setbits8(cpld_base + CPLD_DIUCSR, 0x01 << 4);
+		setbits8(cpld_base + CPLD_DIUCSR, CPLD_DIUCSR_BACKLIGHT);
+		break;
+	default:
+		pr_err("%s: Unsupported monitor port %i\n", __func__, port);
+	}
+
+	iounmap(cpld_base);
+exit:
+	of_node_put(cpld_node);
+}
+
+/**
+ * t1042rdb_set_pixel_clock: program the DIU's clock
+ * @pixclock: pixel clock in ps (pico seconds)
+ */
+static void t1042rdb_set_pixel_clock(unsigned int pixclock)
+{
+	struct device_node *scfg_np;
+	void __iomem *scfg;
+	unsigned long freq;
+	u64 temp;
+	u32 pxclk;
+
+	scfg_np = of_find_compatible_node(NULL, NULL, "fsl,t1040-scfg");
+	if (!scfg_np) {
+		pr_err("%s: Missing scfg node. Can not display video.\n",
+		       __func__);
+		return;
+	}
+
+	scfg = of_iomap(scfg_np, 0);
+	of_node_put(scfg_np);
+	if (!scfg) {
+		pr_err("%s: Could not map device. Can not display video.\n",
+		       __func__);
+		return;
+	}
+
+	/* Convert pixclock into frequency */
+	temp = 1000000000000ULL;
+	do_div(temp, pixclock);
+	freq = temp;
+
+	/*
+	 * 'pxclk' is the ratio of the platform clock to the pixel clock.
+	 * This number is programmed into the PIXCLKCR register, and the valid
+	 * range of values is 2-255.
+	 */
+	pxclk = DIV_ROUND_CLOSEST(fsl_get_sys_freq(), freq);
+	pxclk = clamp_t(u32, pxclk, 2, 255);
+
+	/* Disable the pixel clock, and set it to non-inverted and no delay */
+	clrbits32(scfg + CCSR_SCFG_PIXCLKCR,
+		  PIXCLKCR_PXCKEN | PIXCLKCR_PXCKDLY | PIXCLKCR_PXCLK_MASK);
+
+	/* Enable the clock and set the pxclk */
+	setbits32(scfg + CCSR_SCFG_PIXCLKCR, PIXCLKCR_PXCKEN | (pxclk << 16));
+
+	iounmap(scfg);
+}
+
+/**
+ * t1042rdb_valid_monitor_port: set the monitor port for sysfs
+ */
+static enum fsl_diu_monitor_port
+t1042rdb_valid_monitor_port(enum fsl_diu_monitor_port port)
+{
+	switch (port) {
+	case FSL_DIU_PORT_DVI:
+	case FSL_DIU_PORT_LVDS:
+		return port;
+	default:
+		return FSL_DIU_PORT_DVI; /* Dual-link LVDS is not supported */
+	}
+}
+
+static int __init t1042rdb_diu_init(void)
+{
+	cpld_node = of_find_compatible_node(NULL, NULL, "fsl,t1042rdb-cpld");
+	if (!cpld_node)
+		return 0;
+
+	diu_ops.set_monitor_port	= t1042rdb_set_monitor_port;
+	diu_ops.set_pixel_clock		= t1042rdb_set_pixel_clock;
+	diu_ops.valid_monitor_port	= t1042rdb_valid_monitor_port;
+
+	return 0;
+}
+
+early_initcall(t1042rdb_diu_init);