video: imxfb: Add DT support

Add devicetree support for imx framebuffer driver. It uses the generic
display bindings and helper functions.
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>

Documentation/devicetree/bindings/video/fsl,imx-fb.txt

+Freescale imx21 Framebuffer
+
+This framebuffer driver supports devices imx1, imx21, imx25, and imx27.
+
+Required properties:
+- compatible : "fsl,<chip>-fb", chip should be imx1 or imx21
+- reg : Should contain 1 register ranges(address and length)
+- interrupts : One interrupt of the fb dev
+
+Required nodes:
+- display: Phandle to a display node as described in
+	Documentation/devicetree/bindings/video/display-timing.txt
+	Additional, the display node has to define properties:
+	- bits-per-pixel: Bits per pixel
+	- fsl,pcr: LCDC PCR value
+
+Optional properties:
+- fsl,dmacr: DMA Control Register value. This is optional. By default, the
+	register is not modified as recommended by the datasheet.
+- fsl,lscr1: LCDC Sharp Configuration Register value.
+
+Example:
+
+	imxfb: fb@10021000 {
+		compatible = "fsl,imx21-fb";
+		interrupts = <61>;
+		reg = <0x10021000 0x1000>;
+		display = <&display0>;
+	};
+
+	...
+
+	display0: display0 {
+		model = "Primeview-PD050VL1";
+		native-mode = <&timing_disp0>;
+		bits-per-pixel = <16>;
+		fsl,pcr = <0xf0c88080>;	/* non-standard but required */
+		display-timings {
+			timing_disp0: 640x480 {
+				hactive = <640>;
+				vactive = <480>;
+				hback-porch = <112>;
+				hfront-porch = <36>;
+				hsync-len = <32>;
+				vback-porch = <33>;
+				vfront-porch = <33>;
+				vsync-len = <2>;
+				clock-frequency = <25000000>;
+			};
+		};
+	};

drivers/video/Kconfig

@@ -367,6 +367,8 @@ config FB_IMX
 	select FB_CFB_FILLRECT
 	select FB_CFB_COPYAREA
 	select FB_CFB_IMAGEBLIT
+	select FB_MODE_HELPERS
+	select VIDEOMODE_HELPERS
 
 config FB_CYBER2000
 	tristate "CyberPro 2000/2010/5000 support"

drivers/video/imxfb.c

@@ -31,6 +31,12 @@
 #include <linux/dma-mapping.h>
 #include <linux/io.h>
 #include <linux/math64.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+
+#include <video/of_display_timing.h>
+#include <video/of_videomode.h>
+#include <video/videomode.h>
 
 #include <linux/platform_data/video-imxfb.h>
 
@@ -112,10 +118,11 @@
 #define LCDISR_EOF	(1<<1)
 #define LCDISR_BOF	(1<<0)
 
+#define IMXFB_LSCR1_DEFAULT 0x00120300
+
 /* Used fb-mode. Can be set on kernel command line, therefore file-static. */
 static const char *fb_mode;
 
-
 /*
  * These are the bitfields for each
  * display depth that we support.
@@ -187,6 +194,19 @@ static struct platform_device_id imxfb_devtype[] = {
 };
 MODULE_DEVICE_TABLE(platform, imxfb_devtype);
 
+static struct of_device_id imxfb_of_dev_id[] = {
+	{
+		.compatible = "fsl,imx1-fb",
+		.data = &imxfb_devtype[IMX1_FB],
+	}, {
+		.compatible = "fsl,imx21-fb",
+		.data = &imxfb_devtype[IMX21_FB],
+	}, {
+		/* sentinel */
+	}
+};
+MODULE_DEVICE_TABLE(of, imxfb_of_dev_id);
+
 static inline int is_imx1_fb(struct imxfb_info *fbi)
 {
 	return fbi->devtype == IMX1_FB;
@@ -319,6 +339,9 @@ static const struct imx_fb_videomode *imxfb_find_mode(struct imxfb_info *fbi)
 	struct imx_fb_videomode *m;
 	int i;
 
+	if (!fb_mode)
+		return &fbi->mode[0];
+
 	for (i = 0, m = &fbi->mode[0]; i < fbi->num_modes; i++, m++) {
 		if (!strcmp(m->mode.name, fb_mode))
 			return m;
@@ -474,6 +497,9 @@ static int imxfb_bl_update_status(struct backlight_device *bl)
 	struct imxfb_info *fbi = bl_get_data(bl);
 	int brightness = bl->props.brightness;
 
+	if (!fbi->pwmr)
+		return 0;
+
 	if (bl->props.power != FB_BLANK_UNBLANK)
 		brightness = 0;
 	if (bl->props.fb_blank != FB_BLANK_UNBLANK)
@@ -684,10 +710,14 @@ static int imxfb_activate_var(struct fb_var_screeninfo *var, struct fb_info *inf
 
 	writel(fbi->pcr, fbi->regs + LCDC_PCR);
 #ifndef PWMR_BACKLIGHT_AVAILABLE
-	writel(fbi->pwmr, fbi->regs + LCDC_PWMR);
+	if (fbi->pwmr)
+		writel(fbi->pwmr, fbi->regs + LCDC_PWMR);
 #endif
 	writel(fbi->lscr1, fbi->regs + LCDC_LSCR1);
-	writel(fbi->dmacr, fbi->regs + LCDC_DMACR);
+
+	/* dmacr = 0 is no valid value, as we need DMA control marks. */
+	if (fbi->dmacr)
+		writel(fbi->dmacr, fbi->regs + LCDC_DMACR);
 
 	return 0;
 }
@@ -723,13 +753,12 @@ static int imxfb_resume(struct platform_device *dev)
 #define imxfb_resume	NULL
 #endif
 
-static int __init imxfb_init_fbinfo(struct platform_device *pdev)
+static int imxfb_init_fbinfo(struct platform_device *pdev)
 {
 	struct imx_fb_platform_data *pdata = pdev->dev.platform_data;
 	struct fb_info *info = dev_get_drvdata(&pdev->dev);
 	struct imxfb_info *fbi = info->par;
-	struct imx_fb_videomode *m;
-	int i;
+	struct device_node *np;
 
 	pr_debug("%s\n",__func__);
 
@@ -760,41 +789,95 @@ static int __init imxfb_init_fbinfo(struct platform_device *pdev)
 	info->fbops			= &imxfb_ops;
 	info->flags			= FBINFO_FLAG_DEFAULT |
 					  FBINFO_READS_FAST;
-	info->var.grayscale		= pdata->cmap_greyscale;
-	fbi->cmap_inverse		= pdata->cmap_inverse;
-	fbi->cmap_static		= pdata->cmap_static;
-	fbi->lscr1			= pdata->lscr1;
-	fbi->dmacr			= pdata->dmacr;
-	fbi->pwmr			= pdata->pwmr;
-	fbi->lcd_power			= pdata->lcd_power;
-	fbi->backlight_power		= pdata->backlight_power;
-
-	for (i = 0, m = &pdata->mode[0]; i < pdata->num_modes; i++, m++)
-		info->fix.smem_len = max_t(size_t, info->fix.smem_len,
-				m->mode.xres * m->mode.yres * m->bpp / 8);
+	if (pdata) {
+		info->var.grayscale		= pdata->cmap_greyscale;
+		fbi->cmap_inverse		= pdata->cmap_inverse;
+		fbi->cmap_static		= pdata->cmap_static;
+		fbi->lscr1			= pdata->lscr1;
+		fbi->dmacr			= pdata->dmacr;
+		fbi->pwmr			= pdata->pwmr;
+		fbi->lcd_power			= pdata->lcd_power;
+		fbi->backlight_power		= pdata->backlight_power;
+	} else {
+		np = pdev->dev.of_node;
+		info->var.grayscale = of_property_read_bool(np,
+						"cmap-greyscale");
+		fbi->cmap_inverse = of_property_read_bool(np, "cmap-inverse");
+		fbi->cmap_static = of_property_read_bool(np, "cmap-static");
+
+		fbi->lscr1 = IMXFB_LSCR1_DEFAULT;
+		of_property_read_u32(np, "fsl,lscr1", &fbi->lscr1);
+
+		of_property_read_u32(np, "fsl,dmacr", &fbi->dmacr);
+
+		/* These two function pointers could be used by some specific
+		 * platforms. */
+		fbi->lcd_power = NULL;
+		fbi->backlight_power = NULL;
+	}
+
+	return 0;
+}
+
+static int imxfb_of_read_mode(struct device *dev, struct device_node *np,
+		struct imx_fb_videomode *imxfb_mode)
+{
+	int ret;
+	struct fb_videomode *of_mode = &imxfb_mode->mode;
+	u32 bpp;
+	u32 pcr;
+
+	ret = of_property_read_string(np, "model", &of_mode->name);
+	if (ret)
+		of_mode->name = NULL;
+
+	ret = of_get_fb_videomode(np, of_mode, OF_USE_NATIVE_MODE);
+	if (ret) {
+		dev_err(dev, "Failed to get videomode from DT\n");
+		return ret;
+	}
+
+	ret = of_property_read_u32(np, "bits-per-pixel", &bpp);
+	ret |= of_property_read_u32(np, "fsl,pcr", &pcr);
+
+	if (ret) {
+		dev_err(dev, "Failed to read bpp and pcr from DT\n");
+		return -EINVAL;
+	}
+
+	if (bpp < 1 || bpp > 255) {
+		dev_err(dev, "Bits per pixel have to be between 1 and 255\n");
+		return -EINVAL;
+	}
+
+	imxfb_mode->bpp = bpp;
+	imxfb_mode->pcr = pcr;
 
 	return 0;
 }
 
-static int __init imxfb_probe(struct platform_device *pdev)
+static int imxfb_probe(struct platform_device *pdev)
 {
 	struct imxfb_info *fbi;
 	struct fb_info *info;
 	struct imx_fb_platform_data *pdata;
 	struct resource *res;
+	struct imx_fb_videomode *m;
+	const struct of_device_id *of_id;
 	int ret, i;
+	int bytes_per_pixel;
 
 	dev_info(&pdev->dev, "i.MX Framebuffer driver\n");
 
+	of_id = of_match_device(imxfb_of_dev_id, &pdev->dev);
+	if (of_id)
+		pdev->id_entry = of_id->data;
+
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!res)
 		return -ENODEV;
 
 	pdata = pdev->dev.platform_data;
-	if (!pdata) {
-		dev_err(&pdev->dev,"No platform_data available\n");
-		return -ENOMEM;
-	}
 
 	info = framebuffer_alloc(sizeof(struct imxfb_info), &pdev->dev);
 	if (!info)
@@ -802,15 +885,55 @@ static int __init imxfb_probe(struct platform_device *pdev)
 
 	fbi = info->par;
 
-	if (!fb_mode)
-		fb_mode = pdata->mode[0].mode.name;
-
 	platform_set_drvdata(pdev, info);
 
 	ret = imxfb_init_fbinfo(pdev);
 	if (ret < 0)
 		goto failed_init;
 
+	if (pdata) {
+		if (!fb_mode)
+			fb_mode = pdata->mode[0].mode.name;
+
+		fbi->mode = pdata->mode;
+		fbi->num_modes = pdata->num_modes;
+	} else {
+		struct device_node *display_np;
+		fb_mode = NULL;
+
+		display_np = of_parse_phandle(pdev->dev.of_node, "display", 0);
+		if (!display_np) {
+			dev_err(&pdev->dev, "No display defined in devicetree\n");
+			ret = -EINVAL;
+			goto failed_of_parse;
+		}
+
+		/*
+		 * imxfb does not support more modes, we choose only the native
+		 * mode.
+		 */
+		fbi->num_modes = 1;
+
+		fbi->mode = devm_kzalloc(&pdev->dev,
+				sizeof(struct imx_fb_videomode), GFP_KERNEL);
+		if (!fbi->mode) {
+			ret = -ENOMEM;
+			goto failed_of_parse;
+		}
+
+		ret = imxfb_of_read_mode(&pdev->dev, display_np, fbi->mode);
+		if (ret)
+			goto failed_of_parse;
+	}
+
+	/* Calculate maximum bytes used per pixel. In most cases this should
+	 * be the same as m->bpp/8 */
+	m = &fbi->mode[0];
+	bytes_per_pixel = (m->bpp + 7) / 8;
+	for (i = 0; i < fbi->num_modes; i++, m++)
+		info->fix.smem_len = max_t(size_t, info->fix.smem_len,
+				m->mode.xres * m->mode.yres * bytes_per_pixel);
+
 	res = request_mem_region(res->start, resource_size(res),
 				DRIVER_NAME);
 	if (!res) {
@@ -843,7 +966,8 @@ static int __init imxfb_probe(struct platform_device *pdev)
 		goto failed_ioremap;
 	}
 
-	if (!pdata->fixed_screen_cpu) {
+	/* Seems not being used by anyone, so no support for oftree */
+	if (!pdata || !pdata->fixed_screen_cpu) {
 		fbi->map_size = PAGE_ALIGN(info->fix.smem_len);
 		fbi->map_cpu = dma_alloc_writecombine(&pdev->dev,
 				fbi->map_size, &fbi->map_dma, GFP_KERNEL);
@@ -868,18 +992,16 @@ static int __init imxfb_probe(struct platform_device *pdev)
 		info->fix.smem_start = fbi->screen_dma;
 	}
 
-	if (pdata->init) {
+	if (pdata && pdata->init) {
 		ret = pdata->init(fbi->pdev);
 		if (ret)
 			goto failed_platform_init;
 	}
 
-	fbi->mode = pdata->mode;
-	fbi->num_modes = pdata->num_modes;
 
 	INIT_LIST_HEAD(&info->modelist);
-	for (i = 0; i < pdata->num_modes; i++)
-		fb_add_videomode(&pdata->mode[i].mode, &info->modelist);
+	for (i = 0; i < fbi->num_modes; i++)
+		fb_add_videomode(&fbi->mode[i].mode, &info->modelist);
 
 	/*
 	 * This makes sure that our colour bitfield
@@ -909,10 +1031,10 @@ static int __init imxfb_probe(struct platform_device *pdev)
 failed_register:
 	fb_dealloc_cmap(&info->cmap);
 failed_cmap:
-	if (pdata->exit)
+	if (pdata && pdata->exit)
 		pdata->exit(fbi->pdev);
 failed_platform_init:
-	if (!pdata->fixed_screen_cpu)
+	if (pdata && !pdata->fixed_screen_cpu)
 		dma_free_writecombine(&pdev->dev,fbi->map_size,fbi->map_cpu,
 			fbi->map_dma);
 failed_map:
@@ -921,6 +1043,7 @@ static int __init imxfb_probe(struct platform_device *pdev)
 failed_getclock:
 	release_mem_region(res->start, resource_size(res));
 failed_req:
+failed_of_parse:
 	kfree(info->pseudo_palette);
 failed_init:
 	framebuffer_release(info);
@@ -944,7 +1067,7 @@ static int imxfb_remove(struct platform_device *pdev)
 	unregister_framebuffer(info);
 
 	pdata = pdev->dev.platform_data;
-	if (pdata->exit)
+	if (pdata && pdata->exit)
 		pdata->exit(fbi->pdev);
 
 	fb_dealloc_cmap(&info->cmap);
@@ -971,6 +1094,7 @@ static struct platform_driver imxfb_driver = {
 	.shutdown	= imxfb_shutdown,
 	.driver		= {
 		.name	= DRIVER_NAME,
+		.of_match_table = imxfb_of_dev_id,
 	},
 	.id_table	= imxfb_devtype,
 };