sh_mobile_meram: MERAM framework for LCDC

Based on the patch by Takanari Hayama <taki@igel.co.jp>

Adds support framework necessary to use Media RAM (MERAM)
caching functionality with the LCDC.  The MERAM is accessed
through up to 4 Interconnect Buffers (ICBs).

ICB numbers and MERAM address ranges to use are specified in
by filling in the .meram_cfg member of the LCDC platform data

Signed-off-by: Damian Hobson-Garcia <dhobsong@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 553 insertions, 0 deletions

diff --git a/drivers/video/sh_mobile_meram.c b/drivers/video/sh_mobile_meram.c
new file mode 100644
index 000000000000..bd68f3d43ab5
--- /dev/null
+++ b/drivers/video/sh_mobile_meram.c
@@ -0,0 +1,553 @@
+/*
+ * SuperH Mobile MERAM Driver for SuperH Mobile LCDC Driver
+ *
+ * Copyright (c) 2011	Damian Hobson-Garcia <dhobsong@igel.co.jp>
+ *                      Takanari Hayama <taki@igel.co.jp>
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+
+#include "sh_mobile_meram.h"
+
+/* meram registers */
+#define MExxCTL 0x0
+#define MExxBSIZE 0x4
+#define MExxMNCF 0x8
+#define MExxSARA 0x10
+#define MExxSARB 0x14
+#define MExxSBSIZE 0x18
+
+#define MERAM_MExxCTL_VAL(ctl, next_icb, addr)	\
+	((ctl) | (((next_icb) & 0x1f) << 11) | (((addr) & 0x7ff) << 16))
+#define	MERAM_MExxBSIZE_VAL(a, b, c) \
+	(((a) << 28) | ((b) << 16) | (c))
+
+#define MEVCR1 0x4
+#define MEACTS 0x10
+#define MEQSEL1 0x40
+#define MEQSEL2 0x44
+
+/* settings */
+#define MERAM_SEC_LINE 15
+#define MERAM_LINE_WIDTH 2048
+
+/*
+ * MERAM/ICB access functions
+ */
+
+#define MERAM_ICB_OFFSET(base, idx, off)	\
+	((base) + (0x400 + ((idx) * 0x20) + (off)))
+
+static inline void meram_write_icb(void __iomem *base, int idx, int off,
+	unsigned long val)
+{
+	iowrite32(val, MERAM_ICB_OFFSET(base, idx, off));
+}
+
+static inline unsigned long meram_read_icb(void __iomem *base, int idx, int off)
+{
+	return ioread32(MERAM_ICB_OFFSET(base, idx, off));
+}
+
+static inline void meram_write_reg(void __iomem *base, int off,
+		unsigned long val)
+{
+	iowrite32(val, base + off);
+}
+
+static inline unsigned long meram_read_reg(void __iomem *base, int off)
+{
+	return ioread32(base + off);
+}
+
+/*
+ * register ICB
+ */
+
+#define MERAM_CACHE_START(p)	 ((p) >> 16)
+#define MERAM_CACHE_END(p)	 ((p) & 0xffff)
+#define MERAM_CACHE_SET(o, s)	 ((((o) & 0xffff) << 16) | \
+				  (((o) + (s) - 1) & 0xffff))
+
+/*
+ * check if there's no overlaps in MERAM allocation.
+ */
+
+static inline int meram_check_overlap(struct sh_mobile_meram_priv *priv,
+				      struct sh_mobile_meram_icb *new)
+{
+	int i;
+	int used_start, used_end, meram_start, meram_end;
+
+	/* valid ICB? */
+	if (new->marker_icb & ~0x1f || new->cache_icb & ~0x1f)
+		return 1;
+
+	if (test_bit(new->marker_icb, &priv->used_icb) ||
+			test_bit(new->cache_icb,  &priv->used_icb))
+		return  1;
+
+	for (i = 0; i < priv->used_meram_cache_regions; i++) {
+		used_start = MERAM_CACHE_START(priv->used_meram_cache[i]);
+		used_end   = MERAM_CACHE_END(priv->used_meram_cache[i]);
+		meram_start = new->meram_offset;
+		meram_end   = new->meram_offset + new->meram_size;
+
+		if ((meram_start >= used_start && meram_start < used_end) ||
+			(meram_end > used_start && meram_end < used_end))
+			return 1;
+	}
+
+	return 0;
+}
+
+/*
+ * mark the specified ICB as used
+ */
+
+static inline void meram_mark(struct sh_mobile_meram_priv *priv,
+			      struct sh_mobile_meram_icb *new)
+{
+	int n;
+
+	if (new->marker_icb < 0 || new->cache_icb < 0)
+		return;
+
+	__set_bit(new->marker_icb, &priv->used_icb);
+	__set_bit(new->cache_icb, &priv->used_icb);
+
+	n = priv->used_meram_cache_regions;
+
+	priv->used_meram_cache[n] = MERAM_CACHE_SET(new->meram_offset,
+						    new->meram_size);
+
+	priv->used_meram_cache_regions++;
+}
+
+/*
+ * unmark the specified ICB as used
+ */
+
+static inline void meram_unmark(struct sh_mobile_meram_priv *priv,
+				struct sh_mobile_meram_icb *icb)
+{
+	int i;
+	unsigned long pattern;
+
+	if (icb->marker_icb < 0 || icb->cache_icb < 0)
+		return;
+
+	__clear_bit(icb->marker_icb, &priv->used_icb);
+	__clear_bit(icb->cache_icb, &priv->used_icb);
+
+	pattern = MERAM_CACHE_SET(icb->meram_offset, icb->meram_size);
+	for (i = 0; i < priv->used_meram_cache_regions; i++) {
+		if (priv->used_meram_cache[i] == pattern) {
+			while (i < priv->used_meram_cache_regions - 1) {
+				priv->used_meram_cache[i] =
+					priv->used_meram_cache[i + 1] ;
+				i++;
+			}
+			priv->used_meram_cache[i] = 0;
+			priv->used_meram_cache_regions--;
+			break;
+		}
+	}
+}
+
+
+/*
+ * set the next address to fetch
+ */
+static inline void meram_set_next_addr(struct sh_mobile_meram_priv *priv,
+				       struct sh_mobile_meram_cfg *cfg,
+				       unsigned long base_addr_y,
+				       unsigned long base_addr_c)
+{
+	unsigned long target;
+
+	target = (cfg->current_reg) ? MExxSARA : MExxSARB;
+	cfg->current_reg ^= 1;
+
+	/* set the next address to fetch */
+	meram_write_icb(priv->base, cfg->icb[0].cache_icb,  target,
+			base_addr_y);
+	meram_write_icb(priv->base, cfg->icb[0].marker_icb, target,
+			base_addr_y + cfg->icb[0].cache_unit);
+
+	if (cfg->pixelformat == SH_MOBILE_MERAM_PF_NV) {
+		meram_write_icb(priv->base, cfg->icb[1].cache_icb,  target,
+				base_addr_c);
+		meram_write_icb(priv->base, cfg->icb[1].marker_icb, target,
+				base_addr_c + cfg->icb[1].cache_unit);
+	}
+}
+
+/*
+ * get the next ICB address
+ */
+static inline void meram_get_next_icb_addr(struct sh_mobile_meram_info *pdata,
+					   struct sh_mobile_meram_cfg *cfg,
+					   unsigned long *icb_addr_y,
+					   unsigned long *icb_addr_c)
+{
+	unsigned long icb_offset;
+
+	if (pdata->addr_mode == SH_MOBILE_MERAM_MODE0)
+		icb_offset = 0x80000000 | (cfg->current_reg << 29);
+	else
+		icb_offset = 0xc0000000 | (cfg->current_reg << 23);
+
+	*icb_addr_y = icb_offset | (cfg->icb[0].marker_icb << 24);
+	if ((*icb_addr_c) && cfg->pixelformat == SH_MOBILE_MERAM_PF_NV)
+		*icb_addr_c = icb_offset | (cfg->icb[1].marker_icb << 24);
+}
+
+#define MERAM_CALC_BYTECOUNT(x, y) \
+	(((x) * (y) + (MERAM_LINE_WIDTH - 1)) & ~(MERAM_LINE_WIDTH - 1))
+
+/*
+ * initialize MERAM
+ */
+
+static int meram_init(struct sh_mobile_meram_priv *priv,
+		      struct sh_mobile_meram_icb *icb,
+		      int xres, int yres, int *out_pitch)
+{
+	unsigned long total_byte_count = MERAM_CALC_BYTECOUNT(xres, yres);
+	unsigned long bnm;
+	int lcdc_pitch, xpitch, line_cnt;
+	int save_lines;
+
+	/* adjust pitch to 1024, 2048, 4096 or 8192 */
+	lcdc_pitch = (xres - 1) | 1023;
+	lcdc_pitch = lcdc_pitch | (lcdc_pitch >> 1);
+	lcdc_pitch = lcdc_pitch | (lcdc_pitch >> 2);
+	lcdc_pitch += 1;
+
+	/* derive settings */
+	if (lcdc_pitch == 8192 && yres >= 1024) {
+		lcdc_pitch = xpitch = MERAM_LINE_WIDTH;
+		line_cnt = total_byte_count >> 11;
+		*out_pitch = xres;
+		save_lines = (icb->meram_size / 16 / MERAM_SEC_LINE);
+		save_lines *= MERAM_SEC_LINE;
+	} else {
+		xpitch = xres;
+		line_cnt = yres;
+		*out_pitch = lcdc_pitch;
+		save_lines = icb->meram_size / (lcdc_pitch >> 10) / 2;
+		save_lines &= 0xff;
+	}
+	bnm = (save_lines - 1) << 16;
+
+	/* TODO: we better to check if we have enough MERAM buffer size */
+
+	/* set up ICB */
+	meram_write_icb(priv->base, icb->cache_icb,  MExxBSIZE,
+			MERAM_MExxBSIZE_VAL(0x0, line_cnt - 1, xpitch - 1));
+	meram_write_icb(priv->base, icb->marker_icb, MExxBSIZE,
+			MERAM_MExxBSIZE_VAL(0xf, line_cnt - 1, xpitch - 1));
+
+	meram_write_icb(priv->base, icb->cache_icb,  MExxMNCF, bnm);
+	meram_write_icb(priv->base, icb->marker_icb, MExxMNCF, bnm);
+
+	meram_write_icb(priv->base, icb->cache_icb,  MExxSBSIZE, xpitch);
+	meram_write_icb(priv->base, icb->marker_icb, MExxSBSIZE, xpitch);
+
+	/* save a cache unit size */
+	icb->cache_unit = xres * save_lines;
+
+	/*
+	 * Set MERAM for framebuffer
+	 *
+	 * 0x70f:  WD = 0x3, WS=0x1, CM=0x1, MD=FB mode
+	 * we also chain the cache_icb and the marker_icb.
+	 * we also split the allocated MERAM buffer between two ICBs.
+	 */
+	meram_write_icb(priv->base, icb->cache_icb, MExxCTL,
+			MERAM_MExxCTL_VAL(0x70f, icb->marker_icb,
+					  icb->meram_offset));
+	meram_write_icb(priv->base, icb->marker_icb, MExxCTL,
+			MERAM_MExxCTL_VAL(0x70f, icb->cache_icb,
+					  icb->meram_offset +
+					  icb->meram_size / 2));
+
+	return 0;
+}
+
+static void meram_deinit(struct sh_mobile_meram_priv *priv,
+			struct sh_mobile_meram_icb *icb)
+{
+	/* disable ICB */
+	meram_write_icb(priv->base, icb->cache_icb,  MExxCTL, 0);
+	meram_write_icb(priv->base, icb->marker_icb, MExxCTL, 0);
+	icb->cache_unit = 0;
+}
+
+/*
+ * register the ICB
+ */
+
+static int sh_mobile_meram_register(struct sh_mobile_meram_info *pdata,
+				    struct sh_mobile_meram_cfg *cfg,
+				    int xres, int yres, int pixelformat,
+				    unsigned long base_addr_y,
+				    unsigned long base_addr_c,
+				    unsigned long *icb_addr_y,
+				    unsigned long *icb_addr_c,
+				    int *pitch)
+{
+	struct platform_device *pdev;
+	struct sh_mobile_meram_priv *priv;
+	int n, out_pitch;
+	int error = 0;
+
+	if (!pdata || !pdata->priv || !pdata->pdev || !cfg)
+		return -EINVAL;
+
+	if (pixelformat != SH_MOBILE_MERAM_PF_NV &&
+	    pixelformat != SH_MOBILE_MERAM_PF_RGB)
+		return -EINVAL;
+
+	priv = pdata->priv;
+	pdev = pdata->pdev;
+
+	dev_dbg(&pdev->dev, "registering %dx%d (%s) (y=%08lx, c=%08lx)",
+		xres, yres, (!pixelformat) ? "yuv" : "rgb",
+		base_addr_y, base_addr_c);
+
+	mutex_lock(&priv->lock);
+
+	/* we can't handle wider than 8192px */
+	if (xres > 8192) {
+		dev_err(&pdev->dev, "width exceeding the limit (> 8192).");
+		error = -EINVAL;
+		goto err;
+	}
+
+	if (priv->used_meram_cache_regions + 2 > SH_MOBILE_MERAM_ICB_NUM) {
+		dev_err(&pdev->dev, "no more ICB available.");
+		error = -EINVAL;
+		goto err;
+	}
+
+	/* do we have at least one ICB config? */
+	if (cfg->icb[0].marker_icb < 0 || cfg->icb[0].cache_icb < 0) {
+		dev_err(&pdev->dev, "at least one ICB is required.");
+		error = -EINVAL;
+		goto err;
+	}
+
+	/* make sure that there's no overlaps */
+	if (meram_check_overlap(priv, &cfg->icb[0])) {
+		dev_err(&pdev->dev, "conflicting config detected.");
+		error = -EINVAL;
+		goto err;
+	}
+	n = 1;
+
+	/* do the same if we have the second ICB set */
+	if (cfg->icb[1].marker_icb >= 0 && cfg->icb[1].cache_icb >= 0) {
+		if (meram_check_overlap(priv, &cfg->icb[1])) {
+			dev_err(&pdev->dev, "conflicting config detected.");
+			error = -EINVAL;
+			goto err;
+		}
+		n = 2;
+	}
+
+	if (pixelformat == SH_MOBILE_MERAM_PF_NV && n != 2) {
+		dev_err(&pdev->dev, "requires two ICB sets for planar Y/C.");
+		error =  -EINVAL;
+		goto err;
+	}
+
+	/* we now register the ICB */
+	cfg->pixelformat = pixelformat;
+	meram_mark(priv, &cfg->icb[0]);
+	if (pixelformat == SH_MOBILE_MERAM_PF_NV)
+		meram_mark(priv, &cfg->icb[1]);
+
+	/* initialize MERAM */
+	meram_init(priv, &cfg->icb[0], xres, yres, &out_pitch);
+	*pitch = out_pitch;
+	if (pixelformat == SH_MOBILE_MERAM_PF_NV)
+		meram_init(priv, &cfg->icb[1], xres, (yres + 1) / 2,
+			&out_pitch);
+
+	cfg->current_reg = 1;
+	meram_set_next_addr(priv, cfg, base_addr_y, base_addr_c);
+	meram_get_next_icb_addr(pdata, cfg, icb_addr_y, icb_addr_c);
+
+	dev_dbg(&pdev->dev, "registered - can access via y=%08lx, c=%08lx",
+		*icb_addr_y, *icb_addr_c);
+
+err:
+	mutex_unlock(&priv->lock);
+	return error;
+}
+
+static int sh_mobile_meram_unregister(struct sh_mobile_meram_info *pdata,
+				      struct sh_mobile_meram_cfg *cfg)
+{
+	struct sh_mobile_meram_priv *priv;
+
+	if (!pdata || !pdata->priv || !cfg)
+		return -EINVAL;
+
+	priv = pdata->priv;
+
+	mutex_lock(&priv->lock);
+
+	/* deinit & unmark */
+	if (cfg->pixelformat == SH_MOBILE_MERAM_PF_NV) {
+		meram_deinit(priv, &cfg->icb[1]);
+		meram_unmark(priv, &cfg->icb[1]);
+	}
+	meram_deinit(priv, &cfg->icb[0]);
+	meram_unmark(priv, &cfg->icb[0]);
+
+	mutex_unlock(&priv->lock);
+
+	return 0;
+}
+
+static int sh_mobile_meram_update(struct sh_mobile_meram_info *pdata,
+				  struct sh_mobile_meram_cfg *cfg,
+				  unsigned long base_addr_y,
+				  unsigned long base_addr_c,
+				  unsigned long *icb_addr_y,
+				  unsigned long *icb_addr_c)
+{
+	struct sh_mobile_meram_priv *priv;
+
+	if (!pdata || !pdata->priv || !cfg)
+		return -EINVAL;
+
+	priv = pdata->priv;
+
+	mutex_lock(&priv->lock);
+
+	meram_set_next_addr(priv, cfg, base_addr_y, base_addr_c);
+	meram_get_next_icb_addr(pdata, cfg, icb_addr_y, icb_addr_c);
+
+	mutex_unlock(&priv->lock);
+
+	return 0;
+}
+
+static struct sh_mobile_meram_ops sh_mobile_meram_ops = {
+	.module			= THIS_MODULE,
+	.meram_register		= sh_mobile_meram_register,
+	.meram_unregister	= sh_mobile_meram_unregister,
+	.meram_update		= sh_mobile_meram_update,
+};
+
+/*
+ * initialize MERAM
+ */
+
+static int sh_mobile_meram_remove(struct platform_device *pdev);
+
+static int __devinit sh_mobile_meram_probe(struct platform_device *pdev)
+{
+	struct sh_mobile_meram_priv *priv;
+	struct sh_mobile_meram_info *pdata = pdev->dev.platform_data;
+	struct resource *res;
+	int error;
+
+	if (!pdata) {
+		dev_err(&pdev->dev, "no platform data defined\n");
+		return -EINVAL;
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(&pdev->dev, "cannot get platform resources\n");
+		return -ENOENT;
+	}
+
+	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+	if (!priv) {
+		dev_err(&pdev->dev, "cannot allocate device data\n");
+		return -ENOMEM;
+	}
+
+	platform_set_drvdata(pdev, priv);
+
+	/* initialize private data */
+	mutex_init(&priv->lock);
+	priv->base = ioremap_nocache(res->start, resource_size(res));
+	if (!priv->base) {
+		dev_err(&pdev->dev, "ioremap failed\n");
+		error = -EFAULT;
+		goto err;
+	}
+	pdata->ops = &sh_mobile_meram_ops;
+	pdata->priv = priv;
+	pdata->pdev = pdev;
+
+	/* initialize ICB addressing mode */
+	if (pdata->addr_mode == SH_MOBILE_MERAM_MODE1)
+		meram_write_reg(priv->base, MEVCR1, 1 << 29);
+
+	dev_info(&pdev->dev, "sh_mobile_meram initialized.");
+
+	return 0;
+
+err:
+	sh_mobile_meram_remove(pdev);
+
+	return error;
+}
+
+
+static int sh_mobile_meram_remove(struct platform_device *pdev)
+{
+	struct sh_mobile_meram_priv *priv = platform_get_drvdata(pdev);
+
+	if (priv->base)
+		iounmap(priv->base);
+
+	mutex_destroy(&priv->lock);
+
+	kfree(priv);
+
+	return 0;
+}
+
+static struct platform_driver sh_mobile_meram_driver = {
+	.driver	= {
+		.name		= "sh_mobile_meram",
+		.owner		= THIS_MODULE,
+	},
+	.probe		= sh_mobile_meram_probe,
+	.remove		= sh_mobile_meram_remove,
+};
+
+static int __init sh_mobile_meram_init(void)
+{
+	return platform_driver_register(&sh_mobile_meram_driver);
+}
+
+static void __exit sh_mobile_meram_exit(void)
+{
+	platform_driver_unregister(&sh_mobile_meram_driver);
+}
+
+module_init(sh_mobile_meram_init);
+module_exit(sh_mobile_meram_exit);
+
+MODULE_DESCRIPTION("SuperH Mobile MERAM driver");
+MODULE_AUTHOR("Damian Hobson-Garcia / Takanari Hayama");
+MODULE_LICENSE("GPL v2");