From mboxrd@z Thu Jan  1 00:00:00 1970
From: Alexander Shiyan <shc_work@mail.ru>
Date: Thu, 20 Mar 2014 16:24:34 +0000
Subject: [PATCH 1/3] video: clps711x: Add new Cirrus Logic CLPS711X framebuffer driver
Message-Id: <1395332675-23135-2-git-send-email-shc_work@mail.ru>
List-Id: <linux-fbdev.vger.kernel.org>
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
To: linux-fbdev@vger.kernel.org

This adds support for the framebuffer available in the Cirrus
Logic CLPS711X CPUs.
The driver have been tested with custom board equipped Cirrus Logic
EP7312 in DT and non-DT mode.

Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
---
 drivers/video/fbdev/clps711x-fb.c | 456 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 456 insertions(+)
 create mode 100644 drivers/video/fbdev/clps711x-fb.c

diff --git a/drivers/video/fbdev/clps711x-fb.c b/drivers/video/fbdev/clps711x-fb.c
new file mode 100644
index 0000000..87fd42d
--- /dev/null
+++ b/drivers/video/fbdev/clps711x-fb.c
@@ -0,0 +1,456 @@
+/*
+ * Cirrus Logic CLPS711X FB driver
+ *
+ * Copyright (C) 2014 Alexander Shiyan <shc_work@mail.ru>
+ * Based on driver by Russell King <rmk@arm.linux.org.uk>
+ *
+ * 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/clk.h>
+#include <linux/fb.h>
+#include <linux/io.h>
+#include <linux/lcd.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/mfd/syscon.h>
+#include <linux/mfd/syscon/clps711x.h>
+#include <linux/regulator/consumer.h>
+#include <video/of_display_timing.h>
+
+#define CLPS711X_FB_NAME	"clps711x-fb"
+#define CLPS711X_FB_BPP_MAX	(4)
+
+/* Registers relative to LCDCON */
+#define CLPS711X_LCDCON		(0x0000)
+# define LCDCON_GSEN		BIT(30)
+# define LCDCON_GSMD		BIT(31)
+#define CLPS711X_PALLSW		(0x0280)
+#define CLPS711X_PALMSW		(0x02c0)
+#define CLPS711X_FBADDR		(0x0d40)
+
+struct clps711x_fb_info {
+	struct clk		*clk;
+	void __iomem		*base;
+	struct regmap		*syscon;
+	resource_size_t		buffsize;
+	struct fb_videomode	mode;
+	struct regulator	*lcd_pwr;
+	u32			ac_prescale;
+	bool			cmap_invert;
+};
+
+static int clps711x_fb_setcolreg(u_int regno, u_int red, u_int green,
+				 u_int blue, u_int transp, struct fb_info *info)
+{
+	struct clps711x_fb_info *cfb = info->par;
+	u32 level, mask, shift;
+
+	if (regno >= BIT(info->var.bits_per_pixel))
+		return -EINVAL;
+
+	shift = 4 * (regno & 7);
+	mask  = 0xf << shift;
+	/* gray = 0.30*R + 0.58*G + 0.11*B */
+	level = (((red * 77 + green * 151 + blue * 28) >> 20) << shift) & mask;
+	if (cfb->cmap_invert)
+		level = 0xf - level;
+
+	regno = (regno < 8) ? CLPS711X_PALLSW : CLPS711X_PALMSW;
+
+	writel((readl(cfb->base + regno) & ~mask) | level, cfb->base + regno);
+
+	return 0;
+}
+
+static int clps711x_fb_check_var(struct fb_var_screeninfo *var,
+				 struct fb_info *info)
+{
+	u32 val;
+
+	if (var->bits_per_pixel < 1 ||
+	    var->bits_per_pixel > CLPS711X_FB_BPP_MAX)
+		return -EINVAL;
+
+	if (!var->pixclock)
+		return -EINVAL;
+
+	val = DIV_ROUND_UP(var->xres, 16) - 1;
+	if (val < 0x01 || val > 0x3f)
+		return -EINVAL;
+
+	val = DIV_ROUND_UP(var->yres * var->xres * var->bits_per_pixel, 128);
+	val--;
+	if (val < 0x001 || val > 0x1fff)
+		return -EINVAL;
+
+	var->transp.msb_right	= 0;
+	var->transp.offset	= 0;
+	var->transp.length	= 0;
+	var->red.msb_right	= 0;
+	var->red.offset		= 0;
+	var->red.length		= var->bits_per_pixel;
+	var->green		= var->red;
+	var->blue		= var->red;
+	var->grayscale		= var->bits_per_pixel > 1;
+
+	return 0;
+}
+
+static int clps711x_fb_set_par(struct fb_info *info)
+{
+	struct clps711x_fb_info *cfb = info->par;
+	resource_size_t size;
+	u32 lcdcon, pps;
+
+	size = (info->var.xres * info->var.yres * info->var.bits_per_pixel) / 8;
+	if (size > cfb->buffsize)
+		return -EINVAL;
+
+	switch (info->var.bits_per_pixel) {
+	case 1:
+		info->fix.visual = FB_VISUAL_MONO01;
+		break;
+	case 2:
+	case 4:
+		info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	info->fix.line_length = info->var.xres * info->var.bits_per_pixel / 8;
+	info->fix.smem_len = size;
+
+	lcdcon = (info->var.xres * info->var.yres *
+		  info->var.bits_per_pixel) / 128 - 1;
+	lcdcon |= ((info->var.xres / 16) - 1) << 13;
+	lcdcon |= (cfb->ac_prescale & 0x1f) << 25;
+
+	pps = clk_get_rate(cfb->clk) / (PICOS2KHZ(info->var.pixclock) * 1000);
+	if (pps)
+		pps--;
+	lcdcon |= (pps & 0x3f) << 19;
+
+	if (info->var.bits_per_pixel = 4)
+		lcdcon |= LCDCON_GSMD;
+	if (info->var.bits_per_pixel >= 2)
+		lcdcon |= LCDCON_GSEN;
+
+	/* LCDCON must only be changed while the LCD is disabled */
+	regmap_update_bits(cfb->syscon, SYSCON_OFFSET, SYSCON1_LCDEN, 0);
+	writel(lcdcon, cfb->base + CLPS711X_LCDCON);
+	regmap_update_bits(cfb->syscon, SYSCON_OFFSET,
+			   SYSCON1_LCDEN, SYSCON1_LCDEN);
+
+	return 0;
+}
+
+static int clps711x_fb_blank(int blank, struct fb_info *info)
+{
+	/* Return happy */
+	return 0;
+}
+
+static struct fb_ops clps711x_fb_ops = {
+	.owner		= THIS_MODULE,
+	.fb_setcolreg	= clps711x_fb_setcolreg,
+	.fb_check_var	= clps711x_fb_check_var,
+	.fb_set_par	= clps711x_fb_set_par,
+	.fb_blank	= clps711x_fb_blank,
+	.fb_fillrect	= sys_fillrect,
+	.fb_copyarea	= sys_copyarea,
+	.fb_imageblit	= sys_imageblit,
+};
+
+static int clps711x_lcd_check_fb(struct lcd_device *lcddev, struct fb_info *fi)
+{
+	struct clps711x_fb_info *cfb = dev_get_drvdata(&lcddev->dev);
+
+	return (!fi || fi->par = cfb) ? 1 : 0;
+}
+
+static int clps711x_lcd_get_power(struct lcd_device *lcddev)
+{
+	struct clps711x_fb_info *cfb = dev_get_drvdata(&lcddev->dev);
+
+	if (!IS_ERR_OR_NULL(cfb->lcd_pwr))
+		return regulator_is_enabled(cfb->lcd_pwr);
+
+	return 1;
+}
+
+static int clps711x_lcd_set_power(struct lcd_device *lcddev, int power)
+{
+	struct clps711x_fb_info *cfb = dev_get_drvdata(&lcddev->dev);
+
+	if (!IS_ERR_OR_NULL(cfb->lcd_pwr)) {
+		if (power)
+			return regulator_enable(cfb->lcd_pwr);
+		else
+			return regulator_disable(cfb->lcd_pwr);
+	}
+
+	return 0;
+}
+
+static struct lcd_ops clps711x_lcd_ops = {
+	.check_fb	= clps711x_lcd_check_fb,
+	.get_power	= clps711x_lcd_get_power,
+	.set_power	= clps711x_lcd_set_power,
+};
+
+static int clps711x_fb_get_mode(struct platform_device *pdev)
+{
+	struct fb_info *info = platform_get_drvdata(pdev);
+	bool *pinvert = dev_get_platdata(&pdev->dev);
+	struct clps711x_fb_info *cfb = info->par;
+	unsigned long pixclk;
+	unsigned int val;
+	int ret;
+
+	cfb->syscon = syscon_regmap_lookup_by_pdevname("syscon.1");
+	if (IS_ERR(cfb->syscon))
+		return PTR_ERR(cfb->syscon);
+
+	ret = regmap_read(cfb->syscon, SYSCON_OFFSET, &val);
+	if (ret)
+		return ret;
+
+	if (pinvert)
+		cfb->cmap_invert = *pinvert;
+
+	/* Get mode from LCD if active */
+	if (val & SYSCON1_LCDEN) {
+		val = readl(cfb->base + CLPS711X_LCDCON);
+
+		switch (val & (LCDCON_GSMD | LCDCON_GSEN)) {
+		case LCDCON_GSMD | LCDCON_GSEN:
+			info->var.bits_per_pixel = 4;
+			break;
+		case LCDCON_GSEN:
+			info->var.bits_per_pixel = 2;
+			break;
+		default:
+			info->var.bits_per_pixel = 1;
+			break;
+		}
+
+		cfb->mode.xres = (((val >> 13) & 0x3f) + 1) * 16;
+		cfb->mode.yres = (((val & 0x1fff) + 1) * 128) /
+				 (cfb->mode.xres * info->var.bits_per_pixel);
+		cfb->ac_prescale = (val >> 25) & 0x1f;
+		pixclk = clk_get_rate(cfb->clk) / (((val >> 19) & 0x3f) + 1);
+	} else {
+		/* Fixed setup for existing users */
+		info->var.bits_per_pixel = 4;
+		cfb->mode.xres = 640;
+		cfb->mode.yres = 240;
+		cfb->ac_prescale = 13;
+		pixclk = 10000000;
+	}
+
+	cfb->mode.refresh = pixclk / (cfb->mode.xres * cfb->mode.yres);
+	cfb->mode.pixclock = KHZ2PICOS(pixclk / 1000);
+
+	return 0;
+}
+
+static int clps711x_fb_get_mode_dt(struct platform_device *pdev)
+{
+	struct device_node *disp, *np = pdev->dev.of_node;
+	struct fb_info *info = platform_get_drvdata(pdev);
+	struct clps711x_fb_info *cfb = info->par;
+	int ret;
+
+	cfb->syscon +		syscon_regmap_lookup_by_compatible("cirrus,clps711x-syscon1");
+	if (IS_ERR(cfb->syscon))
+		return PTR_ERR(cfb->syscon);
+
+	disp = of_parse_phandle(np, "display", 0);
+	if (!disp) {
+		dev_err(&pdev->dev, "No display defined\n");
+		return -ENODATA;
+	}
+
+	ret = of_get_fb_videomode(disp, &cfb->mode, OF_USE_NATIVE_MODE);
+	if (ret)
+		return ret;
+
+	of_property_read_u32(disp, "ac-prescale", &cfb->ac_prescale);
+	cfb->cmap_invert = of_property_read_bool(disp, "cmap-invert");
+
+	return of_property_read_u32(disp, "bits-per-pixel",
+				    &info->var.bits_per_pixel);
+}
+
+static int clps711x_fb_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct clps711x_fb_info *cfb;
+	struct lcd_device *lcd;
+	struct fb_info *info;
+	struct resource *res;
+	int ret = -ENOENT;
+	u32 val;
+
+	if (fb_get_options(CLPS711X_FB_NAME, NULL))
+		return -ENODEV;
+
+	info = framebuffer_alloc(sizeof(*cfb), dev);
+	if (!info)
+		return -ENOMEM;
+
+	cfb = info->par;
+	platform_set_drvdata(pdev, info);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		goto out_fb_release;
+	cfb->base = devm_ioremap(dev, res->start, resource_size(res));
+	if (!cfb->base) {
+		ret = -ENOMEM;
+		goto out_fb_release;
+	}
+
+	info->fix.mmio_start = res->start;
+	info->fix.mmio_len = resource_size(res);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	info->screen_base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(info->screen_base)) {
+		ret = PTR_ERR(info->screen_base);
+		goto out_fb_release;
+	}
+
+	/* Physical address should be aligned to 256 MiB */
+	if (res->start & 0x0fffffff) {
+		ret = -EINVAL;
+		goto out_fb_release;
+	}
+
+	info->apertures = alloc_apertures(1);
+	if (!info->apertures) {
+		ret = -ENOMEM;
+		goto out_fb_release;
+	}
+
+	cfb->buffsize = resource_size(res);
+	info->fix.smem_start = res->start;
+	info->apertures->ranges[0].base = info->fix.smem_start;
+	info->apertures->ranges[0].size = cfb->buffsize;
+
+	cfb->clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(cfb->clk)) {
+		ret = PTR_ERR(cfb->clk);
+		goto out_fb_release;
+	}
+
+	ret = np ? clps711x_fb_get_mode_dt(pdev) : clps711x_fb_get_mode(pdev);
+	if (ret)
+		goto out_fb_release;
+
+	/* Force disable LCD on any mismatch */
+	if (info->fix.smem_start != (readb(cfb->base + CLPS711X_FBADDR) << 28))
+		regmap_update_bits(cfb->syscon, SYSCON_OFFSET,
+				   SYSCON1_LCDEN, 0);
+
+	ret = regmap_read(cfb->syscon, SYSCON_OFFSET, &val);
+	if (ret)
+		goto out_fb_release;
+
+	if (!(val & SYSCON1_LCDEN)) {
+		/* Setup start FB address */
+		writeb(info->fix.smem_start >> 28, cfb->base + CLPS711X_FBADDR);
+		/* Clean FB memory */
+		memset(info->screen_base, 0, cfb->buffsize);
+	}
+
+	cfb->lcd_pwr = devm_regulator_get(dev, "lcd");
+	if (PTR_ERR(cfb->lcd_pwr) = -EPROBE_DEFER) {
+		ret = -EPROBE_DEFER;
+		goto out_fb_release;
+	}
+
+	info->fbops = &clps711x_fb_ops;
+	info->flags = FBINFO_DEFAULT;
+	info->var.activate = FB_ACTIVATE_FORCE | FB_ACTIVATE_NOW;
+	info->var.height = -1;
+	info->var.width = -1;
+	info->var.vmode = FB_VMODE_NONINTERLACED;
+	info->fix.type = FB_TYPE_PACKED_PIXELS;
+	info->fix.accel = FB_ACCEL_NONE;
+	strlcpy(info->fix.id, CLPS711X_FB_NAME, sizeof(info->fix.id));
+	fb_videomode_to_var(&info->var, &cfb->mode);
+
+	ret = fb_alloc_cmap(&info->cmap, BIT(CLPS711X_FB_BPP_MAX), 0);
+	if (ret)
+		goto out_fb_release;
+
+	ret = fb_set_var(info, &info->var);
+	if (ret)
+		goto out_fb_dealloc_cmap;
+
+	ret = register_framebuffer(info);
+	if (ret)
+		goto out_fb_dealloc_cmap;
+
+	lcd = devm_lcd_device_register(dev, "clps711x-lcd", dev, cfb,
+				       &clps711x_lcd_ops);
+	if (!IS_ERR(lcd))
+		return 0;
+	
+	ret = PTR_ERR(lcd);
+	unregister_framebuffer(info);
+
+out_fb_dealloc_cmap:
+	regmap_update_bits(cfb->syscon, SYSCON_OFFSET, SYSCON1_LCDEN, 0);
+	fb_dealloc_cmap(&info->cmap);
+
+out_fb_release:
+	framebuffer_release(info);
+
+	return ret;
+}
+
+static int clps711x_fb_remove(struct platform_device *pdev)
+{
+	struct fb_info *info = platform_get_drvdata(pdev);
+	struct clps711x_fb_info *cfb = info->par;
+
+	regmap_update_bits(cfb->syscon, SYSCON_OFFSET, SYSCON1_LCDEN, 0);
+
+	unregister_framebuffer(info);
+	fb_dealloc_cmap(&info->cmap);
+	framebuffer_release(info);
+
+	return 0;
+}
+
+static const struct of_device_id __maybe_unused clps711x_fb_dt_ids[] = {
+	{ .compatible = "cirrus,clps711x-fb", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, clps711x_fb_dt_ids);
+
+static struct platform_driver clps711x_fb_driver = {
+	.driver	= {
+		.name		= CLPS711X_FB_NAME,
+		.owner		= THIS_MODULE,
+		.of_match_table	= of_match_ptr(clps711x_fb_dt_ids),
+	},
+	.probe	= clps711x_fb_probe,
+	.remove	= clps711x_fb_remove,
+};
+module_platform_driver(clps711x_fb_driver);
+
+MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
+MODULE_DESCRIPTION("Cirrus Logic CLPS711X FB driver");
+MODULE_LICENSE("GPL");
-- 
1.8.3.2